title: Ideal gas

text: The ideal gas law is an extension of experimentally discovered gas laws. It can also be derived from microscopic considerations.


title: Ideal gas

text: Real fluids at low density and high temperature approximate the behavior of a classical ideal gas. However, at lower temperatures or a higher density, a real fluid deviates strongly from the behavior of an ideal gas, particularly as it condenses from a gas into a liquid or as it deposits from a gas into a solid. This deviation is expressed as a compressibility factor.


title: Ideal gas

text: The other equation of state of an ideal gas must express Joule's second law, that the internal energy of a fixed mass of ideal gas is a function only of its temperature, with formula_8. For the present purposes it is convenient to postulate an exemplary version of this law by writing:


title: Ideal gas

text: That for an ideal gas depends only on temperature is a consequence of the ideal gas law, although in the general case depends on temperature and an integral is needed to compute .


title: Ideal gas

text: In order to switch from macroscopic quantities (left hand side of the following equation) to microscopic ones (right hand side), we use


title: Ideal gas

text: The probability distribution of particles by velocity or energy is given by the Maxwell speed distribution.


title: Ideal gas

text: The assumption of spherical particles is necessary so that there are no rotational modes allowed, unlike in a diatomic gas. The following three assumptions are very related: molecules are hard, collisions are elastic, and there are no inter-molecular forces. The assumption that the space between particles is much larger than the particles themselves is of paramount importance, and explains why the ideal gas approximation fails at high pressures.


title: Ideal gas

text: where is the entropy. This quantity is generally a function of temperature due to intermolecular and intramolecular forces, but for moderate temperatures it is approximately constant. Specifically, the Equipartition Theorem predicts that the constant for a monatomic gas is  =  while for a diatomic gas it is  =  if vibrations are neglected (which is often an excellent approximation). Since the heat capacity depends on the atomic or molecular nature of the gas, macroscopic measurements on heat capacity provide useful information on the microscopic structure of the molecules.


title: Ideal gas

text: Sometimes, a distinction is made between an ideal gas, where and could vary with temperature, and a perfect gas, for which this is not the case.


title: Ideal gas

text: For air, which is a mixture of gases, this ratio can be assumed to be 1.4 with only a small error over a wide temperature range.


title: Ideal gas

text: Using the results of thermodynamics only, we can go a long way in determining the expression for the entropy of an ideal gas. This is an important step since, according to the theory of thermodynamic potentials, if we can express the entropy as a function of ( is a thermodynamic potential), volume and the number of particles , then we will have a complete statement of the thermodynamic behavior of the ideal gas. We will be able to derive both the ideal gas law and the expression for internal energy from it.


title: Ideal gas

text: Since the entropy is an exact differential, using the chain rule, the change in entropy when going from a reference state 0 to some other state with entropy may be written as where:


title: Ideal gas

text: where the reference variables may be functions of the number of particles . Using the definition of the heat capacity at constant volume for the first differential and the appropriate Maxwell relation for the second we have:


title: Ideal gas

text: Expressing in terms of as developed in the above section, differentiating the ideal gas equation of state, and integrating yields:


title: Ideal gas

text: where all constants have been incorporated into the logarithm as which is some function of the particle number having the same dimensions as in order that the argument of the logarithm be dimensionless. We now impose the constraint that the entropy be extensive. This will mean that when the extensive parameters ( and ) are multiplied by a constant, the entropy will be multiplied by the same constant. Mathematically:


title: Ideal gas

text: Differentiating this with respect to , setting equal to 1, and then solving the differential equation yields :


title: Ideal gas

text: where may vary for different gases, but will be independent of the thermodynamic state of the gas. It will have the dimensions of . Substituting into the equation for the entropy:


title: Ideal gas

text: Since this is an expression for entropy in terms of , , and , it is a fundamental equation from which all other properties of the ideal gas may be derived.


title: Ideal gas

text: This is about as far as we can go using thermodynamics alone. Note that the above equation is flawed – as the temperature approaches zero, the entropy approaches negative infinity, in contradiction to the third law of thermodynamics. In the above "ideal" development, there is a critical point, not at absolute zero, at which the argument of the logarithm becomes unity, and the entropy becomes zero. This is unphysical. The above equation is a good approximation only when the argument of the logarithm is much larger than unity – the concept of an ideal gas breaks down at low values of . Nevertheless, there will be a "best" value of the constant in the sense that the predicted entropy is as close as possible to the actual entropy, given the flawed assumption of ideality. A quantum-mechanical derivation of this constant is developed in the derivation of the Sackur–Tetrode equation which expresses the entropy of a monatomic () ideal gas. In the Sackur–Tetrode theory the constant depends only upon the mass of the gas particle. The Sackur–Tetrode equation also suffers from a divergent entropy at absolute zero, but is a good approximation for the entropy of a monatomic ideal gas for high enough temperatures.


title: Ideal gas

text: The chemical potential of the ideal gas is calculated from the corresponding equation of state (see thermodynamic potential):


title: Ideal gas

text: The chemical potential is usually referenced to the potential at some standard pressure "P" so that, with formula_29:


title: Ideal gas

text: For a mixture ("j"=1,2...) of ideal gases, each at partial pressure "P", it can be shown that the chemical potential "μ" will be given by the above expression with the pressure "P" replaced by "P".


title: Ideal gas

text: The most informative way of writing the potentials is in terms of their natural variables, since each of these equations can be used to derive all of the other thermodynamic variables of the system. In terms of their natural variables, the thermodynamic potentials of a single-species ideal gas are:


title: Ideal gas

text: In statistical mechanics, the relationship between the Helmholtz free energy and the partition function is fundamental, and is used to calculate the thermodynamic properties of matter; see configuration integral for more details.


title: Ideal gas

text: In the above-mentioned Sackur–Tetrode equation, the best choice of the entropy constant was found to be proportional to the quantum thermal wavelength of a particle, and the point at which the argument of the logarithm becomes zero is roughly equal to the point at which the average distance between particles becomes equal to the thermal wavelength. In fact, quantum theory itself predicts the same thing. Any gas behaves as an ideal gas at high enough temperature and low enough density, but at the point where the Sackur–Tetrode equation begins to break down, the gas will begin to behave as a quantum gas, composed of either bosons or fermions. (See the gas in a box article for a derivation of the ideal quantum gases, including the ideal Boltzmann gas.)


title: Ideal gas

text: Gases tend to behave as an ideal gas over a wider range of pressures when the temperature reaches the Boyle temperature.


title: Ideal gas

text: The ideal Boltzmann gas yields the same results as the classical thermodynamic gas, but makes the following identification for the undetermined constant :


title: Ideal gas

text: An ideal gas of bosons (e.g. a photon gas) will be governed by Bose–Einstein statistics and the distribution of energy will be in the form of a Bose–Einstein distribution. An ideal gas of fermions will be governed by Fermi–Dirac statistics and the distribution of energy will be in the form of a Fermi–Dirac distribution.


title: Heat of combustion

text: The heating value (or energy value or calorific value) of a substance, usually a fuel or food (see food energy), is the amount of heat released during the combustion of a specified amount of it.


title: Heat of combustion

text: The "calorific value" is the total energy released as heat when a substance undergoes complete combustion with oxygen under standard conditions. The chemical reaction is typically a hydrocarbon or other organic molecule reacting with oxygen to form carbon dioxide and water and release heat. It may be expressed with the quantities:


title: Heat of combustion

text: There are two kinds of enthalpy of combustion, called high(er) and low(er) heat(ing) value, depending on how much the products are allowed to cool and whether compounds like are allowed to condense.


title: Heat of combustion

text: The high heat values are conventionally measured with a bomb calorimeter. Low heat values are calculated from high heat value test data. They may also be calculated as the difference between the heat of formation Δ"H" of the products and reactants (though this approach is somewhat artificial since most heats of formation are typically calculated from measured heats of combustion).


title: Heat of combustion

text: By convention, the (higher) heat of combustion is defined to be the heat released for the complete combustion of a compound in its standard state to form stable products in their standard states: hydrogen is converted to water (in its liquid state), carbon is converted to carbon dioxide gas, and nitrogen is converted to nitrogen gas. That is, the heat of combustion, Δ"H"°, is the heat of reaction of the following process:


title: Heat of combustion

text: Chlorine and sulfur are not quite standardized; they are usually assumed to convert to hydrogen chloride gas and or gas, respectively, or to dilute aqueous hydrochloric and sulfuric acids, respectively, when the combustion is conducted in a bomb calorimeter containing some quantity of water.


title: Heat of combustion

text: Zwolinski and Wilhoit defined, in 1972, "gross" and "net" values for heats of combustion. In the gross definition the products are the most stable compounds, e.g. (l), (l), (s) and (l). In the net definition the products are the gases produced when the compound is burned in an open flame, e.g. (g), (g), (g) and (g). In both definitions the products for C, F, Cl and N are (g), (g), (g) and (g), respectively.


title: Heat of combustion

text: The heating value of a fuel can be calculated with the results of ultimate analysis of fuel. From analysis, percentages of the combustibles in the fuel (carbon, hydrogen, sulfur) are known. Since the heat of combustion of these elements is known, the heating value can be calculated using Dulong's Formula:


title: Heat of combustion

text: where m, m, m, m, and m are the contents of carbon, hydrogen, oxygen, nitrogen, and sulfur on any (wet, dry or ash free) basis, respectively.


title: Heat of combustion

text: The higher heating value (HHV; "gross energy", "upper heating value", "gross calorific value" "GCV", or "higher calorific value"; "HCV") indicates the upper limit of the available thermal energy produced by a complete combustion of fuel. It is measured as a unit of energy per unit mass or volume of substance. The HHV is determined by bringing all the products of combustion back to the original pre-combustion temperature, and in particular condensing any vapor produced. Such measurements often use a standard temperature of . This is the same as the thermodynamic heat of combustion since the enthalpy change for the reaction assumes a common temperature of the compounds before and after combustion, in which case the water produced by combustion is condensed to a liquid. The higher heating value takes into account the latent heat of vaporization of water in the combustion products, and is useful in calculating heating values for fuels where condensation of the reaction products is practical (e.g., in a gas-fired boiler used for space heat). In other words, HHV assumes all the water component is in liquid state at the end of combustion (in product of combustion) and that heat delivered at temperatures below can be put to use.


title: Heat of combustion

text: The lower heating value (LHV; "net calorific value"; "NCV", or "lower calorific value"; "LCV") is another measure of available thermal energy produced by a combustion of fuel, measured as a unit of energy per unit mass or volume of substance. In contrast to the HHV, the LHV considers energy losses such as the energy used to vaporize water - although its exact definition is not uniformly agreed upon. One definition is simply to subtract the heat of vaporization of the water from the higher heating value. This treats any HO formed as a vapor. The energy required to vaporize the water therefore is not released as heat.


title: Heat of combustion

text: LHV calculations assume that the water component of a combustion process is in vapor state at the end of combustion, as opposed to the higher heating value (HHV) (a.k.a. "gross calorific value" or "gross CV") which assumes that all of the water in a combustion process is in a liquid state after a combustion process.


title: Heat of combustion

text: Another definition of the LHV is the amount of heat released when the products are cooled to . This means that the latent heat of vaporization of water and other reaction products is not recovered. It is useful in comparing fuels where condensation of the combustion products is impractical, or heat at a temperature below cannot be put to use.


title: Heat of combustion

text: One definition of lower heating value, adopted by the American Petroleum Institute (API), uses a reference temperature of .


title: Heat of combustion

text: Another definition, used by Gas Processors Suppliers Association (GPSA) and originally used by API (data collected for API research project 44), is the enthalpy of all combustion products minus the enthalpy of the fuel at the reference temperature (API research project 44 used 25 °C. GPSA currently uses 60 °F), minus the enthalpy of the stoichiometric oxygen (O) at the reference temperature, minus the heat of vaporization of the vapor content of the combustion products.


title: Heat of combustion

text: The definition in which the combustion products are all returned to the reference temperature is more easily calculated from the higher heating value than when using other definitions and will in fact give a slightly different answer.


title: Heat of combustion

text: Gross heating value accounts for water in the exhaust leaving as vapor, as does LHV, but gross heating value also includes liquid water in the fuel prior to combustion. This value is important for fuels like wood or coal, which will usually contain some amount of water prior to burning.


title: Heat of combustion

text: The higher heating value is experimentally determined in a bomb calorimeter. The combustion of a stoichiometric mixture of fuel and oxidizer (e.g. two moles of hydrogen and one mole of oxygen) in a steel container at is initiated by an ignition device and the reactions allowed to complete. When hydrogen and oxygen react during combustion, water vapor is produced. The vessel and its contents are then cooled to the original 25 °C and the higher heating value is determined as the heat released between identical initial and final temperatures.


title: Heat of combustion

text: When the lower heating value (LHV) is determined, cooling is stopped at 150 °C and the reaction heat is only partially recovered. The limit of 150 °C is based on acid gas dew-point.


title: Heat of combustion

text: Note: Higher heating value (HHV) is calculated with the product of water being in liquid form while lower heating value (LHV) is calculated with the product of water being in vapor form.


title: Heat of combustion

text: The difference between the two heating values depends on the chemical composition of the fuel. In the case of pure carbon or carbon monoxide, the two heating values are almost identical, the difference being the sensible heat content of carbon dioxide between 150 °C and 25 °C (sensible heat exchange causes a change of temperature, while latent heat is added or subtracted for phase transitions at constant temperature. Examples: heat of vaporization or heat of fusion). For hydrogen, the difference is much more significant as it includes the sensible heat of water vapor between 150 °C and 100 °C, the latent heat of condensation at 100 °C, and the sensible heat of the condensed water between 100 °C and 25 °C. All in all, the higher heating value of hydrogen is 18.2% above its lower heating value (142MJ/kg vs. 120MJ/kg). For hydrocarbons, the difference depends on the hydrogen content of the fuel. For gasoline and diesel the higher heating value exceeds the lower heating value by about 10% and 7%, respectively, and for natural gas about 11%.


title: Heat of combustion

text: where "H" is the heat of vaporization of water, "n" is the number of moles of water vaporized and "n" is the number of moles of fuel combusted.


title: Heat of combustion

text: Engine manufacturers typically rate their engines fuel consumption by the lower heating values since the exhaust is never condensed in the engine, and doing this allows them to publish more attractive numbers than are used in conventional power plant terms. The conventional power industry had used HHV (high heat value) exclusively for decades, even though virtually all of these plants did not condense exhaust either. American consumers should be aware that the corresponding fuel-consumption figure based on the higher heating value will be somewhat higher.


title: Heat of combustion

text: The difference between HHV and LHV definitions causes endless confusion when quoters do not bother to state the convention being used. since there is typically a 10% difference between the two methods for a power plant burning natural gas. For simply benchmarking part of a reaction the LHV may be appropriate, but HHV should be used for overall energy efficiency calculations if only to avoid confusion, and in any case, the value or convention should be clearly stated.


title: Heat of combustion

text: Both HHV and LHV can be expressed in terms of AR (all moisture counted), MF and MAF (only water from combustion of hydrogen). AR, MF, and MAF are commonly used for indicating the heating values of coal:


title: Heat of combustion

text: The International Energy Agency reports the following typical higher heating values per Standard cubic metre of gas:


title: Heat of combustion

text: The lower heating value of natural gas is normally about 90% of its higher heating value. This table is in Standard cubic metres (1atm, 15°C), to convert to values per Normal cubic metre (1atm, 0°C), multiply above table by 1.0549.


title: Vibration

text: Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin "vibrationem" ("shaking, brandishing"). The oscillations may be periodic, such as the motion of a pendulum—or random, such as the movement of a tire on a gravel road.


title: Vibration

text: Vibration can be desirable: for example, the motion of a tuning fork, the reed in a woodwind instrument or harmonica, a mobile phone, or the cone of a loudspeaker.


title: Vibration

text: In many cases, however, vibration is undesirable, wasting energy and creating unwanted sound. For example, the vibrational motions of engines, electric motors, or any mechanical device in operation are typically unwanted. Such vibrations could be caused by imbalances in the rotating parts, uneven friction, or the meshing of gear teeth. Careful designs usually minimize unwanted vibrations.


title: Vibration

text: The studies of sound and vibration are closely related. Sound, or pressure waves, are generated by vibrating structures (e.g. vocal cords); these pressure waves can also induce the vibration of structures (e.g. ear drum). Hence, attempts to reduce noise are often related to issues of vibration.


title: Vibration

text: Free vibration occurs when a mechanical system is set in motion with an initial input and allowed to vibrate freely. Examples of this type of vibration are pulling a child back on a swing and letting it go, or hitting a tuning fork and letting it ring. The mechanical system vibrates at one or more of its natural frequencies and damps down to motionlessness.


title: Vibration

text: Forced vibration is when a time-varying disturbance (load, displacement, velocity, or acceleration) is applied to a mechanical system. The disturbance can be a periodic and steady-state input, a transient input, or a random input. The periodic input can be a harmonic or a non-harmonic disturbance. Examples of these types of vibration include a washing machine shaking due to an imbalance, transportation vibration caused by an engine or uneven road, or the vibration of a building during an earthquake. For linear systems, the frequency of the steady-state vibration response resulting from the application of a periodic, harmonic input is equal to the frequency of the applied force or motion, with the response magnitude being dependent on the actual mechanical system.


title: Vibration

text: Damped vibration: When the energy of a vibrating system is gradually dissipated by friction and other resistances, the vibrations are said to be damped. The vibrations gradually reduce or change in frequency or intensity or cease and the system rests in its equilibrium position. An example of this type of vibration is the vehicular suspension dampened by the shock absorber.


title: Vibration

text: Vibration testing is accomplished by introducing a forcing function into a structure, usually with some type of shaker. Alternately, a DUT (device under test) is attached to the "table" of a shaker. Vibration testing is performed to examine the response of a device under test (DUT) to a defined vibration environment. The measured response may be ability to function in the vibration environment, fatigue life, resonant frequencies or squeak and rattle sound output (NVH). Squeak and rattle testing is performed with a special type of "quiet shaker" that produces very low sound levels while under operation.


title: Vibration

text: For relatively low frequency forcing (typically less than 100 Hz), servohydraulic (electrohydraulic) shakers are used. For higher frequencies (typically 5 Hz to 2000 Hz), electrodynamic shakers are used. Generally, one or more "input" or "control" points located on the DUT-side of a vibration fixture is kept at a specified acceleration. Other "response" points may experience higher vibration levels (resonance) or lower vibration level (anti-resonance or damping) than the control point(s). It is often desirable to achieve anti-resonance to keep a system from becoming too noisy, or to reduce strain on certain parts due to vibration modes caused by specific vibration frequencies.


title: Vibration

text: The most common types of vibration testing services conducted by vibration test labs are sinusoidal and random. Sine (one-frequency-at-a-time) tests are performed to survey the structural response of the device under test (DUT). During the early history of vibration testing, vibration machine controllers were limited only to controlling sine motion so only sine testing was performed. Later, more sophisticated analog and then digital controllers were able to provide random control (all frequencies at once). A random (all frequencies at once) test is generally considered to more closely replicate a real world environment, such as road inputs to a moving automobile.


title: Vibration

text: Most vibration testing is conducted in a 'single DUT axis' at a time, even though most real-world vibration occurs in various axes simultaneously. MIL-STD-810G, released in late 2008, Test Method 527, calls for multiple exciter testing. The "vibration test fixture" used to attach the DUT to the shaker table must be designed for the frequency range of the vibration test spectrum. It is difficult to design a vibration test fixture which duplicates the dynamic response (mechanical impedance) of the actual in-use mounting. For this reason, to ensure repeatability between vibration tests, vibration fixtures are designed to be resonance free within the test frequency range.


title: Vibration

text: Generally for smaller fixtures and lower frequency ranges, the designer can target a fixture design that is free of resonances in the test frequency range. This becomes more difficult as the DUT gets larger and as the test frequency increases. In these cases multi-point control strategies can mitigate some of the resonances that may be present in the future.


title: Vibration

text: Some vibration test methods limit the amount of crosstalk (movement of a response point in a mutually perpendicular direction to the axis under test) permitted to be exhibited by the vibration test fixture.


title: Vibration

text: Vibration analysis (VA), applied in an industrial or maintenance environment aims to reduce maintenance costs and equipment downtime by detecting equipment faults. VA is a key component of a condition monitoring (CM) program, and is often referred to as predictive maintenance (PdM). Most commonly VA is used to detect faults in rotating equipment (Fans, Motors, Pumps, and Gearboxes etc.) such as imbalance, misalignment, rolling element bearing faults and resonance conditions.


title: Vibration

text: VA can use the units of Displacement, Velocity and Acceleration displayed as a time waveform (TWF), but most commonly the spectrum is used, derived from a fast Fourier transform of the TWF. The vibration spectrum provides important frequency information that can pinpoint the faulty component.


title: Vibration

text: The fundamentals of vibration analysis can be understood by studying the simple Mass-spring-damper model. Indeed, even a complex structure such as an automobile body can be modeled as a "summation" of simple mass–spring–damper models. The mass–spring–damper model is an example of a simple harmonic oscillator. The mathematics used to describe its behavior is identical to other simple harmonic oscillators such as the RLC circuit.


title: Vibration

text: Note: This article does not include the step-by-step mathematical derivations, but focuses on major vibration analysis equations and concepts. Please refer to the references at the end of the article for detailed derivations.


title: Vibration

text: To start the investigation of the mass–spring–damper assume the damping is negligible and that there is no external force applied to the mass (i.e. free vibration). The force applied to the mass by the spring is proportional to the amount the spring is stretched "x" (assuming the spring is already compressed due to the weight of the mass). The proportionality constant, k, is the stiffness of the spring and has units of force/distance (e.g. lbf/in or N/m). The negative sign indicates that the force is always opposing the motion of the mass attached to it:


title: Vibration

text: The force generated by the mass is proportional to the acceleration of the mass as given by Newton's second law of motion:


title: Vibration

text: This solution says that it will oscillate with simple harmonic motion that has an amplitude of "A" and a frequency of "f". The number "f" is called the undamped natural frequency. For the simple mass–spring system, "f" is defined as:


title: Vibration

text: Note: angular frequency ω (ω=2 π "f") with the units of radians per second is often used in equations because it simplifies the equations, but is normally converted to ordinary frequency (units of Hz or equivalently cycles per second) when stating the frequency of a system. If the mass and stiffness of the system is known, the formula above can determine the frequency at which the system vibrates once set in motion by an initial disturbance. Every vibrating system has one or more natural frequencies that it vibrates at once disturbed. This simple relation can be used to understand in general what happens to a more complex system once we add mass or stiffness. For example, the above formula explains why, when a car or truck is fully loaded, the suspension feels ″softer″ than unloaded—the mass has increased, reducing the natural frequency of the system.


title: Vibration

text: Vibrational motion could be understood in terms of conservation of energy. In the above example the spring has been extended by a value of x and therefore some potential energy (formula_6) is stored in the spring. Once released, the spring tends to return to its un-stretched state (which is the minimum potential energy state) and in the process accelerates the mass. At the point where the spring has reached its un-stretched state all the potential energy that we supplied by stretching it has been transformed into kinetic energy (formula_7). The mass then begins to decelerate because it is now compressing the spring and in the process transferring the kinetic energy back to its potential. Thus oscillation of the spring amounts to the transferring back and forth of the kinetic energy into potential energy. In this simple model the mass continues to oscillate forever at the same magnitude—but in a real system, "damping" always dissipates the energy, eventually bringing the spring to rest.


title: Vibration

text: When a "viscous" damper is added to the model this outputs a force that is proportional to the velocity of the mass. The damping is called viscous because it models the effects of a fluid within an object. The proportionality constant "c" is called the damping coefficient and has units of Force over velocity (lbf⋅s/in or N⋅s/m).


title: Vibration

text: The solution to this equation depends on the amount of damping. If the damping is small enough, the system still vibrates—but eventually, over time, stops vibrating. This case is called underdamping, which is important in vibration analysis. If damping is increased just to the point where the system no longer oscillates, the system has reached the point of critical damping. If the damping is increased past critical damping, the system is overdamped. The value that the damping coefficient must reach for critical damping in the mass-spring-damper model is:


title: Vibration

text: To characterize the amount of damping in a system a ratio called the damping ratio (also known as damping factor and % critical damping) is used. This damping ratio is just a ratio of the actual damping over the amount of damping required to reach critical damping. The formula for the damping ratio (formula_11) of the mass-spring-damper model is:


title: Vibration

text: For example, metal structures (e.g., airplane fuselages, engine crankshafts) have damping factors less than 0.05, while automotive suspensions are in the range of 0.2–0.3. The solution to the underdamped system for the mass-spring-damper model is the following:


title: Vibration

text: The value of "X", the initial magnitude, and formula_14 the phase shift, are determined by the amount the spring is stretched. The formulas for these values can be found in the references.


title: Vibration

text: The major points to note from the solution are the exponential term and the cosine function. The exponential term defines how quickly the system “damps” down – the larger the damping ratio, the quicker it damps to zero. The cosine function is the oscillating portion of the solution, but the frequency of the oscillations is different from the undamped case.


title: Vibration

text: The frequency in this case is called the "damped natural frequency", formula_15 and is related to the undamped natural frequency by the following formula:


title: Vibration

text: The damped natural frequency is less than the undamped natural frequency, but for many practical cases the damping ratio is relatively small and hence the difference is negligible. Therefore, the damped and undamped description are often dropped when stating the natural frequency (e.g. with 0.1 damping ratio, the damped natural frequency is only 1% less than the undamped).


title: Vibration

text: The plots to the side present how 0.1 and 0.3 damping ratios effect how the system “rings” down over time. What is often done in practice is to experimentally measure the free vibration after an impact (for example by a hammer) and then determine the natural frequency of the system by measuring the rate of oscillation, as well as the damping ratio by measuring the rate of decay. The natural frequency and damping ratio are not only important in free vibration, but also characterize how a system behaves under forced vibration.


title: Vibration

text: The behavior of the spring mass damper model varies with the addition of a harmonic force. A force of this type could, for example, be generated by a rotating imbalance.


title: Vibration

text: The result states that the mass will oscillate at the same frequency, "f", of the applied force, but with a phase shift formula_20


title: Vibration

text: Where “r” is defined as the ratio of the harmonic force frequency over the undamped natural frequency of the mass–spring–damper model.


title: Vibration

text: The plot of these functions, called "the frequency response of the system", presents one of the most important features in forced vibration. In a lightly damped system when the forcing frequency nears the natural frequency (formula_25) the amplitude of the vibration can get extremely high. This phenomenon is called resonance (subsequently the natural frequency of a system is often referred to as the resonant frequency). In rotor bearing systems any rotational speed that excites a resonant frequency is referred to as a critical speed.


title: Vibration

text: If resonance occurs in a mechanical system it can be very harmful – leading to eventual failure of the system. Consequently, one of the major reasons for vibration analysis is to predict when this type of resonance may occur and then to determine what steps to take to prevent it from occurring. As the amplitude plot shows, adding damping can significantly reduce the magnitude of the vibration. Also, the magnitude can be reduced if the natural frequency can be shifted away from the forcing frequency by changing the stiffness or mass of the system. If the system cannot be changed, perhaps the forcing frequency can be shifted (for example, changing the speed of the machine generating the force).


title: Vibration

text: The following are some other points in regards to the forced vibration shown in the frequency response plots.


title: Vibration

text: Resonance is simple to understand if the spring and mass are viewed as energy storage elements – with the mass storing kinetic energy and the spring storing potential energy. As discussed earlier, when the mass and spring have no external force acting on them they transfer energy back and forth at a rate equal to the natural frequency. In other words, to efficiently pump energy into both mass and spring requires that the energy source feed the energy in at a rate equal to the natural frequency. Applying a force to the mass and spring is similar to pushing a child on swing, a push is needed at the correct moment to make the swing get higher and higher. As in the case of the swing, the force applied need not be high to get large motions, but must just add energy to the system.


title: Vibration

text: The damper, instead of storing energy, dissipates energy. Since the damping force is proportional to the velocity, the more the motion, the more the damper dissipates the energy. Therefore, there is a point when the energy dissipated by the damper equals the energy added by the force. At this point, the system has reached its maximum amplitude and will continue to vibrate at this level as long as the force applied stays the same. If no damping exists, there is nothing to dissipate the energy and, theoretically, the motion will continue to grow into infinity.


title: Vibration

text: In a previous section only a simple harmonic force was applied to the model, but this can be extended considerably using two powerful mathematical tools. The first is the Fourier transform that takes a signal as a function of time (time domain) and breaks it down into its harmonic components as a function of frequency (frequency domain). For example, by applying a force to the mass–spring–damper model that repeats the following cycle – a force equal to 1 newton for 0.5 second and then no force for 0.5 second. This type of force has the shape of a 1 Hz square wave.


title: Vibration

text: The Fourier transform of the square wave generates a frequency spectrum that presents the magnitude of the harmonics that make up the square wave (the phase is also generated, but is typically of less concern and therefore is often not plotted). The Fourier transform can also be used to analyze non-periodic functions such as transients (e.g. impulses) and random functions. The Fourier transform is almost always computed using the fast Fourier transform (FFT) computer algorithm in combination with a window function.


title: Vibration

text: In the case of our square wave force, the first component is actually a constant force of 0.5 newton and is represented by a value at 0 Hz in the frequency spectrum. The next component is a 1 Hz sine wave with an amplitude of 0.64. This is shown by the line at 1 Hz. The remaining components are at odd frequencies and it takes an infinite amount of sine waves to generate the perfect square wave. Hence, the Fourier transform allows you to interpret the force as a sum of sinusoidal forces being applied instead of a more "complex" force (e.g. a square wave).


title: Vibration

text: In the previous section, the vibration solution was given for a single harmonic force, but the Fourier transform in general gives multiple harmonic forces. The second mathematical tool, the superposition principle, allows the summation of the solutions from multiple forces if the system is linear. In the case of the spring–mass–damper model, the system is linear if the spring force is proportional to the displacement and the damping is proportional to the velocity over the range of motion of interest. Hence, the solution to the problem with a square wave is summing the predicted vibration from each one of the harmonic forces found in the frequency spectrum of the square wave.


title: Vibration

text: The solution of a vibration problem can be viewed as an input/output relation – where the force is the input and the output is the vibration. Representing the force and vibration in the frequency domain (magnitude and phase) allows the following relation:


title: Vibration

text: formula_31 is called the frequency response function (also referred to as the transfer function, but not technically as accurate) and has both a magnitude and phase component (if represented as a complex number, a real and imaginary component). The magnitude of the frequency response function (FRF) was presented earlier for the mass–spring–damper system.


title: Vibration

text: For example, calculating the FRF for a mass–spring–damper system with a mass of 1 kg, spring stiffness of 1.93 N/mm and a damping ratio of 0.1. The values of the spring and mass give a natural frequency of 7 Hz for this specific system. Applying the 1 Hz square wave from earlier allows the calculation of the predicted vibration of the mass. The figure illustrates the resulting vibration. It happens in this example that the fourth harmonic of the square wave falls at 7 Hz. The frequency response of the mass–spring–damper therefore outputs a high 7 Hz vibration even though the input force had a relatively low 7 Hz harmonic. This example highlights that the resulting vibration is dependent on both the forcing function and the system that the force is applied to.


title: Vibration

text: The figure also shows the time domain representation of the resulting vibration. This is done by performing an inverse Fourier Transform that converts frequency domain data to time domain. In practice, this is rarely done because the frequency spectrum provides all the necessary information.


title: Vibration

text: The frequency response function (FRF) does not necessarily have to be calculated from the knowledge of the mass, damping, and stiffness of the system—but can be measured experimentally. For example, if a known force over a range of frequencies is applied, and if the associated vibrations are measured, the frequency response function can be calculated, thereby characterizing the system. This technique is used in the field of experimental modal analysis to determine the vibration characteristics of a structure.


title: Vibration

text: The simple mass–spring–damper model is the foundation of vibration analysis, but what about more complex systems? The mass–spring–damper model described above is called a single degree of freedom (SDOF) model since the mass is assumed to only move up and down. In more complex systems, the system must be discretized into more masses that move in more than one direction, adding degrees of freedom. The major concepts of multiple degrees of freedom (MDOF) can be understood by looking at just a 2 degree of freedom model as shown in the figure.


title: Vibration

text: where formula_38 formula_39 and formula_40 are symmetric matrices referred respectively as the mass, damping, and stiffness matrices. The matrices are NxN square matrices where N is the number of degrees of freedom of the system.


title: Vibration

text: The following analysis involves the case where there is no damping and no applied forces (i.e. free vibration). The solution of a viscously damped system is somewhat more complicated.


title: Vibration

text: Note: Using the exponential solution of formula_43 is a mathematical trick used to solve linear differential equations. Using Euler's formula and taking only the real part of the solution it is the same cosine solution for the 1 DOF system. The exponential solution is only used because it is easier to manipulate mathematically.


title: Vibration

text: This is referred to an eigenvalue problem in mathematics and can be put in the standard format by pre-multiplying the equation by formula_47


title: Vibration

text: The solution to the problem results in N eigenvalues (i.e. formula_52), where N corresponds to the number of degrees of freedom. The eigenvalues provide the natural frequencies of the system. When these eigenvalues are substituted back into the original set of equations, the values of formula_53 that correspond to each eigenvalue are called the eigenvectors. These eigenvectors represent the mode shapes of the system. The solution of an eigenvalue problem can be quite cumbersome (especially for problems with many degrees of freedom), but fortunately most math analysis programs have eigenvalue routines.


title: Vibration

text: The eigenvalues and eigenvectors are often written in the following matrix format and describe the modal model of the system:


title: Vibration

text: A simple example using the 2 DOF model can help illustrate the concepts. Let both masses have a mass of 1 kg and the stiffness of all three springs equal 1000 N/m. The mass and stiffness matrix for this problem are then:


title: Vibration

text: The natural frequencies in the units of hertz are then (remembering formula_59) formula_60 and formula_61


title: Vibration

text: Since the system is a 2 DOF system, there are two modes with their respective natural frequencies and shapes. The mode shape vectors are not the absolute motion, but just describe relative motion of the degrees of freedom. In our case the first mode shape vector is saying that the masses are moving together in phase since they have the same value and sign. In the case of the second mode shape vector, each mass is moving in opposite direction at the same rate.


title: Vibration

text: When there are many degrees of freedom, one method of visualizing the mode shapes is by animating them using structural analysis software such as Femap, ANSYS or VA One by ESI Group. An example of animating mode shapes is shown in the figure below for a cantilevered -beam as demonstrated using modal analysis on ANSYS. In this case, the finite element method was used to generate an approximation of the mass and stiffness matrices by meshing the object of interest in order to solve a discrete eigenvalue problem. Note that, in this case, the finite element method provides an approximation of the meshed surface (for which there exists an infinite number of vibration modes and frequencies). Therefore, this relatively simple model that has over 100 degrees of freedom and hence as many natural frequencies and mode shapes, provides a good approximation for the first natural frequencies and modes. Generally, only the first few modes are important for practical applications.


title: Vibration

text: The eigenvectors have very important properties called orthogonality properties. These properties can be used to greatly simplify the solution of multi-degree of freedom models. It can be shown that the eigenvectors have the following properties:


title: Vibration

text: formula_65 and formula_66 are diagonal matrices that contain the modal mass and stiffness values for each one of the modes. (Note: Since the eigenvectors (mode shapes) can be arbitrarily scaled, the orthogonality properties are often used to scale the eigenvectors so the modal mass value for each mode is equal to 1. The modal mass matrix is therefore an identity matrix)


title: Vibration

text: These properties can be used to greatly simplify the solution of multi-degree of freedom models by making the following coordinate transformation.


title: Vibration

text: Using this coordinate transformation in the original free vibration differential equation results in the following equation.


title: Vibration

text: This equation is the foundation of vibration analysis for multiple degree of freedom systems. A similar type of result can be derived for damped systems. The key is that the modal mass and stiffness matrices are diagonal matrices and therefore the equations have been "decoupled". In other words, the problem has been transformed from a large unwieldy multiple degree of freedom problem into many single degree of freedom problems that can be solved using the same methods outlined above.


title: Vibration

text: Solving for "x" is replaced by solving for "q", referred to as the modal coordinates or modal participation factors.


title: Vibration

text: Written in this form it can be seen that the vibration at each of the degrees of freedom is just a linear sum of the mode shapes. Furthermore, how much each mode "participates" in the final vibration is defined by q, its modal participation factor.


title: Vibration

text: An unrestrained multi-degree of freedom system experiences both rigid-body translation and/or rotation and vibration. The existence of a rigid-body mode results in a zero natural frequency. The corresponding mode shape is called the rigid-body mode.


title: Suicide attempt

text: A suicide attempt is an attempt to die by suicide that results in survival. It may be referred to as a "failed" or "unsuccessful" suicide attempt, though these terms are discouraged by mental health professionals for implying that a suicide resulting in death is a successful and positive outcome.


title: Suicide attempt

text: In the United States, the National Institute of Mental Health reports there are 11 nonfatal suicide attempts for every suicide death. The American Association of Suicidology reports higher numbers, stating that there are 25 suicide attempts for every suicide completion. The ratio of suicide attempts to suicide death is about 25:1 in youths, compared to about 4:1 in elderly. A 2008 review found that nonfatal self-injury is more common in women, and a separate study from 2008/2009 found suicidal thoughts higher among females, as well as significant differences between genders for suicide planning and suicide attempts.


title: Suicide attempt

text: Suicide attempts are more common among adolescents in developing countries than developed ones. A 12-month prevalence of suicide attempt in developing countries between 2003 and 2015 was reported as 17%.


title: Suicide attempt

text: Without commonly agreed-upon operational definitions, some suicidology researchers regard many suicide attempts as parasuicide (para=near) or self harm behavior, rather than "true" suicide attempts, as in lacking suicidal intent.


title: Suicide attempt

text: Some suicide methods have higher rates of lethality than others. The use of firearms results in death 90% of the time. Wrist-slashing has a much lower lethality rate, comparatively. 75% of all suicide attempts are by drug overdose, a method that is often thwarted because the drug is nonlethal, or is used at a nonlethal dosage. These people survive 97% of the time.


title: Suicide attempt

text: A nonfatal suicide attempt is the strongest known clinical predictor of eventual suicide. Suicide risk among self-harm patients is hundreds of times higher than in the general population. It is often estimated that about 10–15% of people who attempt suicide eventually die by suicide. The mortality risk is highest during the first months and years after the attempt: almost 1% of individuals who attempt suicide will die by suicide if the attempt is repeated within one year. Recent meta-analytic evidence suggests that the association between suicide attempt and suicidal death may not be as strong as it was thought before.


title: Suicide attempt

text: Suicide attempts can result in serious and permanent injuries and/or disabilities. 700,000 (or more) Americans survive a suicide attempt each year. People who attempt either hanging or carbon monoxide poisoning and survive can face permanent brain damage due to cerebral anoxia. People who take a drug overdose and survive can face severe organ damage (e.g., liver failure). Individuals who jump from a height and survive may face irreversible damage to multiple organs, as well as the spine and brain.


title: Suicide attempt

text: While a majority sustain injuries that allow them to be released following emergency room treatment, a significant minority—about 116,000—are hospitalized, of whom 110,000 are eventually discharged alive. Their average hospital stay is 79 days. Some 89,000, 17% of these people, are permanently disabled.


title: Suicide attempt

text: Historically in the Christian church, people who attempted suicide were excommunicated because of the religiously polarizing nature of the topic. While previously criminally punishable, attempted suicide no longer is in most Western countries. It remains a criminal offense in most Islamic countries. In the late 19th century in Great Britain, attempted suicide was deemed to be equivalent to attempted murder and could be punished by hanging. In the United States, suicide is not illegal and almost no country in Europe currently considers attempted suicide to be a crime.


title: Suicide attempt

text: In India, attempted suicide was decriminalized by the Mental Healthcare Act, 2017, while Singapore removed attempted suicide from their criminal code in 2020; previously it had been punishable by up to one-year in prison.


title: Suicide attempt

text: Many other countries still prosecute suicide attempts. As of 2012, attempted suicide is a criminal offense in Uganda, and as of 2013, it is criminalized in Ghana.


title: Suicide attempt

text: Despite having its own laws, Maryland still reserves the right to prosecute people under the English Common laws that were in place when America declared independence in 1776. These laws were used to convict a man for attempted suicide in 2018, resulting in a three-year suspended sentence and two years of supervised probation.


title: Bob Orton Jr.

text: Robert Keith Orton Jr. (born November 10, 1950), better known by the ring name "Cowboy" Bob Orton, is an American semi-retired professional wrestler. He is the son of professional wrestler Bob Orton Sr., the brother of professional wrestler Barry Orton, and the father of professional wrestler Randy Orton. He is best known for his time in the WWF (World Wrestling Federation, now WWE). He has also wrestled for several promotions in the United States, Japan, and other countries.


title: Bob Orton Jr.

text: Bob Orton Jr. was born in Kansas City, Missouri, and is the son of professional wrestler Bob Orton Sr.


title: Bob Orton Jr.

text: Orton trained with Hiro Matsuda, after dropping out of college, and at the age of 22, Orton made his debut in the promotion Championship Wrestling from Florida in 1972 with the ring name of Young Mr. Wrestling wrestling in instances with his father Bob Orton Sr. They won the tag team title from the promotion. Orton was one of the first wrestlers to use the Superplex as his finishing maneuver. Orton, in his early days in wrestling, used a gimmick of a masked wrestler known as The Invader. He often used this gimmick, until 1976.


title: Bob Orton Jr.

text: Orton spent time in Verne Gagne's American Wrestling Association in 1976 and 1978, a large portion of it under the tutelage of AWA MVP Manager Bobby Heenan. Orton feuded with Greg Gagne among others. Gagne-Orton was a featured match on the AWA undercard for the Muhammad Ali-Antonio Inoki mixed martial arts match.


title: Bob Orton Jr.

text: Orton had a brief stint back in the AWA in early 1988 following his November 1987 dismissal from the WWF, during which he renewed his alliance with Adrian Adonis from the WWF.


title: Bob Orton Jr.

text: Following experiencing success in the Florida, Central States, and Mid-South regions, Orton competed in the National Wrestling Alliance in 1980-1981 using a cowboy's gimmick. While he competed in the NWA, he won several matches and earned a reputation as a hard worker and legit tough wrestler. In 1982, he left the NWA to sign a contract with the World Wrestling Federation.


title: Bob Orton Jr.

text: In 1982, Orton competed in the World Wrestling Federation. He challenged Bob Backlund for the WWF Heavyweight Championship in Philadelphia, winning by count-out (the title cannot change of hands by disqualification or count-out).


title: Bob Orton Jr.

text: He returned to the NWA again in 1982 and captured the tag team title with Don Kernodle. The duo held the title for two months before succumbing to Wahoo McDaniel and Mark Youngblood.


title: Bob Orton Jr.

text: Together with Dick Slater, he had a feud with Ric Flair. Orton and Slater interfered in Flair's return match against NWA World Champion Harley Race, who had beaten Flair for the title. They attacked Flair with an aided piledriver, which caused Flair a severe injury in the neck and put Flair out of wrestling for several months, thus collecting a bounty placed on Flair's head by Race, who was reluctant to wrestle Flair in return matches for the title. In the run-up to this incident, Orton had been portrayed as a babyface and a longtime friend of Flair - his participation in the attack was thus portrayed as the betrayal of that friendship. Flair would eventually return in late 1983, attacking both Orton and Slater with a baseball bat (before going on to win back the title from Race at Starrcade '83).


title: Bob Orton Jr.

text: Orton re-joined the WWF in March 1984 for what would be the most famous run of his career. He was often addressed as "Ace" Orton by Roddy Piper, and was Piper's bodyguard. His other gimmick, wearing a cast during his matches, stemmed from legitimately having his left forearm broken in a match with Jimmy Snuka at the 1985 event "The War to Settle the Score" in Madison Square Garden. Although the injury healed in real life, the "cast" gimmick involved Orton—on "doctor's orders"—continuing to wear the cast, claiming the injury had not healed; Orton instead would use the cast to his advantage, striking his opponents behind the referee's back. He won several matches, with the cast and without the cast.


title: Bob Orton Jr.

text: In 1984, Orton was the #1 contender to the WWF Intercontinental Championship, eventually wrestling then-current champion Tito Santana. Orton was successful in winning untelevised matches and events against Santana, but Orton mostly won by either count-out or disqualification. Orton would also be successful in defeating Santana in non-title bouts, but Santana ultimately remained as the champ, and Santana eventually got the upper hand in the feud.


title: Bob Orton Jr.

text: Orton would also engage in a bitter feud with Jimmy Snuka through 1985 and 1986. Orton, just like with Santana, managed to achieve victories over Snuka but mainly in untelevised shows. Just like his feud with Santana, Snuka would get the upper hand in the feud.


title: Bob Orton Jr.

text: Orton was involved in the main event of the first WrestleMania at Madison Square Garden in 1985, being in the corner of Piper and 'Mr. Wonderful' Paul Orndorff in their match against Hulk Hogan and Mr. T. Orton accidentally cost his team the match after an attempted cheat backfired, resulting in him hitting Orndorff with the cast. Orton also competed in the main event against WWF Champion Hulk Hogan on Saturday Night's Main Event I on NBC broadcast May 11, 1985, which he lost by disqualification due to the interference of Piper. Orton took part in the 1985 King of the Ring tournament on July 8 he fought Paul Orndorff to a double disqualification


title: Bob Orton Jr.

text: Orton remained with Piper for the remainder of 1985, feuding with Orndorff and a variety of partners, such as Hogan, André the Giant, and Bruno Sammartino. In early 1986, Orndorff began wearing a cast as a neutralizer, and the WWF ordered both men to remove their casts. Also, in late 1985 and early 1986, Orton challenged Hogan for the WWF Heavyweight Championship; like his matches four years earlier against Backlund, Orton was not successful. On June 30, at a house show held on Bloomington, Minnesota, Orton and Piper surprisingly scored an upset victory over Orndorff and Hogan, albeit by DQ; this event also would be the first time Orton got a victory over Hogan as previous matches between them typically saw Hogan winning.


title: Bob Orton Jr.

text: Orton was dubbed "Boxing" Bob and "Battling" Bob in early 1986 after the cast came off and fought Mr. T at "Saturday Night's Main Event V", which served as a setup for the Piper-Mr. T match at WrestleMania 2. Prior to WrestleMania 2, "Boxing" Bob Orton defeated Jose Luis Rivera in a boxing match. At WrestleMania 2, Orton was introduced as "Ace in Comedy and Funnyman" by guest ring announcer Joan Rivers, who misread the card.


title: Bob Orton Jr.

text: Piper and Orton went their separate ways after WrestleMania, with Piper taking a hiatus and Orton in the meantime becoming the bodyguard for Piper's talk-segment successor "Adorable" Adrian Adonis; Adonis had Orton wear a pink cowboy hat. When Piper returned later in 1986 to reclaim his talk show segment (turning face in the process), Orton betrayed his long-time friend, sparking a violent feud between Piper and Orton and his new partners, which typically saw Piper winning. During this time, Orton formed a tag team with The Magnificent Muraco, with the duo managed by Mr. Fuji, and sometimes Jimmy Hart. During their first years as a team, the team of Muraco and Orton was given a fairly decent push, and both were able to easily defeat preliminary wrestlers when not teaming. They appeared at the opening match at WrestleMania III, losing to the Can-Am Connection (Rick Martel and Tom Zenk).


title: Bob Orton Jr.

text: The team of Muraco and Orton also got into a series of matches with The Killer Bees (a team composed of B. Brian Blair and Jumpin' Jim Brunzell). Both teams exchanged victories at televised events, but ultimately the Bees got the upper hand at untelevised events. Referee Danny Davis would usually disqualify the Bees as a part of his heel gimmick. They (along Tiger Chung Lee) were notable for being the first team to lose to The Young Stallions (a team composed by Jim Powers and Paul Roma) alongside Tito Santana.


title: Bob Orton Jr.

text: By 1987, the team of Muraco and Orton was clearly stepping down the card. While they were still able to defeat preliminary teams, Orton and Muraco would usually find themselves on the losing end to upper-card teams. Orton and Muraco then eventually started arguing during their matches, which also caused them to lose credibility as a team. This finally led to a match on "WWF Superstars of Wrestling" where Orton caused him and Muraco to lose a match when Orton kept Muraco from performing a Superplex, which was Orton's finishing move. Orton felt offended that Muraco was trying to steal his hold. This led to a brawl between both wrestlers that took place inside and outside the ring. On September 7, 1987, Orton and Muraco finally faced off at a WWF house show. This match ended in a double disqualification. Orton and Muraco faced off during the late months of 1987. By this point, the team was essentially disbanded, with the now turned face "The Rock" Magnificent Muraco getting the upper hand in the feud. During Orton's feud with Muraco, Mr. Fuji would return to manage Orton (Muraco dumped Mr. Fuji as his manager following his face turn). Orton's last televised match and victory as a whole in the WWF came on October 10, 1987, in a heated victory against preliminary wrestler Siva Afi. Orton's last match with the WWF came on November 7, 1987, where Orton fought preliminary wrestler Sam Houston to a draw in his home state of Missouri. Orton was fired after this for getting arrested for causing a disturbance at a Calgary airport.


title: Bob Orton Jr.

text: In 1989, Orton attempted to make a comeback to the WWF, losing to Ted DiBiase in a WWF house show at Springfield, MI on October 11. However, no contract was ever offered to him.


title: Bob Orton Jr.

text: By 1990, Orton was wrestling for the Arena Wrestling Alliance promotion. As the AWA had an agreement with the WWF to exchange talent, Orton made appearances for the WWF, at three house show-matches. All took place in New Zealand. Orton was also scheduled to make an appearance for a WWF show in Madison Square Garden in January 1990 against Bret Hart, but that was cancelled. Then Orton would depart from the company for 15 years before returning in 2005.


title: Bob Orton Jr.

text: After leaving the WWF, Orton took a short hiatus from wrestling, inactive until 1988, when Orton travelled to Japan. During this time, he wrestled for New Japan Pro-Wrestling, working with his brother Barry O, and they formed the team of the Gaspar Brothers, two hockey-masked pirates, with Bob using the ring name of Billy Gaspar while Barry called himself Barry Gaspar. They won several matches together, beating the teams of Nobuhiko Takada and Antonio Inoki, Kuniaki Kobayashi and Riki Choshu, Osamu Kido and Yoshiaki Fujiwara, Hiro Saito and Super Strong Machine and many others. After the team of the Gaspar Brothers ended, Orton briefly teamed with Dick Murdoch and Scott Hall in NJPW for the Japan Cup Elimination League. After wrestling a few more matches in 1989 with a low number of victories, Orton left New Japan.


title: Bob Orton Jr.

text: On March 30, 1989, Orton made his debut with then National Wrestling Alliance member, World Championship Wrestling. Wrestling at a "WCW Saturday Night" taping in Atlanta, Georgia and managed by Gary Hart, Orton defeated Shane Douglas. On the April 1 episode of "Saturday Night", it was announced that Orton would be facing his former partner Dick Murdoch at the upcoming Clash of Champions VI. The following day at the Clash, Orton defeated Murdoch after Gary Hart interfered. He then went on a house show tour facing mostly preliminary opposition. On April 14 in Milwaukee, Wisconsin Orton suffered his first defeat, falling to Mike Justice. Murdoch challenged Orton to a bullrope match after he had interfered in one of Orton's matches, in which Orton defeated Trent Knight. He lost to Murdoch at the 1989 Wrestlewar in the bullrope match. Shortly after the match, Orton's manager "Playboy" Gary Hart started brawling with Murdoch, and then Orton attacked Murdoch with the cowbell of the bullrope, and threw him out of the ring, choking him, and attacking the referees that were trying to stop him in the process. After his release, Orton made a one-time appearance at a WCW house show in Kiel, Missouri, defeating Dutch Mantell.


title: Bob Orton Jr.

text: On February 3, 2005, Bob Orton was announced as a 2005 inductee into the WWE Hall of Fame. In the weeks preceding WrestleMania 21, Orton became entangled in his son Randy's feud with The Undertaker. During an episode of SmackDown!, Orton begged The Undertaker to show mercy on his son in order to distract The Undertaker long enough for his son to sneak into the ring and hit the RKO. At WrestleMania, he (unsuccessfully) interfered in the match between Orton and The Undertaker, striking The Undertaker with his cast. On August 21, 2005, at SummerSlam, Orton interfered in a rematch between Randy and The Undertaker, this time enabling his son to defeat The Undertaker. Orton then began accompanying Randy to ringside during his matches, and teamed with his son at No Mercy on October 9, 2005, defeating The Undertaker in a handicap casket match. The Ortons teamed together once again on the October 28, 2005 episode of "SmackDown!", joining forces with Ken Kennedy to face Roddy Piper, Batista, and Eddie Guerrero in a six-man tag team match. The match ended in defeat for the Ortons when Orton succumbed to Piper's sleeper hold. On the December 16, 2005 episode of SmackDown!, Orton disguised himself as one of the Undertaker's druids and carried The Undertaker's signature urn to ringside as The Undertaker came to the ring to confront Randy. Orton remained at ringside after the other druids had left, distracting The Undertaker and enabling Randy to attack him. Orton then handed Randy the urn, which Randy used to knock The Undertaker unconscious. At Armageddon, Orton (still holding the urn) accompanied Randy to ringside for his Hell in a Cell match with The Undertaker. He interfered in the match several times, but was ultimately unable to prevent The Undertaker from delivering a Tombstone Piledriver to both Ortons and then covering Randy for the win. On February 13, 2006, Orton was released from WWE.


title: Bob Orton Jr.

text: In 1990 he appeared in the Five Star Wrestling Federation in Baton Rouge which was headed by Grizzly Smith, and that same year, Orton appeared in International World Class Championship Wrestling. In 1991 he wrestled for Herb Abrams' Universal Wrestling Federation at their lone pay-per-view Beach Brawl, as well as their live wrestling special Blackjack Brawl. In the UWF, Orton was awarded the UWF Intercontinental Heavyweight Championship as well as winning the UWF Southern States Championship from former rival and tag-team partner Ron Garvin. Orton lost the UWF Southern States Championship to Paul Orndorff, although, Orton was awarded the title back in 1994 when Orndorff left the promotion, vacating the title in the process.


title: Bob Orton Jr.

text: In 1994, Orton made a few appearances for Jim Cornette's Smoky Mountain Wrestling. That same year, Orton wrestled for the American Wrestling Federation, and during his time in the AWF, he was managed by Oliver Humperdink. Orton challenged Tito Santana for the AWF Championship, with AWF commissioner Jim Brunzell as the special referee for the match, but Orton lost the match. During 1995 and 1996 he feuded with Santana. During Orton's time in the AWF, Orton received a big push, and he was the number one contender for Santana's AWF Championship in 1996. He won the AWF Championship in his second attempt, before losing the championship to Santana that same night in the last round. He had a brief feud in 1997 against "Sexy" Ace Steele in MVWA in St. Louis. In 1999, he appeared at the Heroes of Wrestling PPV, in which Orton was defeated by former rival Jimmy Snuka, after an interference of Snuka's manager Lou Albano. He retired from full-time active competition in that same year, but has continued to wrestle on a semi-regular basis.


title: Bob Orton Jr.

text: Orton returned to the ring at Millennium Wrestling Federation Soul Survivor II in 2004, teaming with Todd Hanson and Beau Douglas to defeat "The Ugandan Giant" Kamala, Gino Marktino, and Ox Baker's Executioner.


title: Bob Orton Jr.

text: On October 17, 2009, Orton (accompanied by his youngest son Nathan) performed at Independent Hardcore Wrestling against "Bloody" Harker Dirge, in a match for the Pro Wrestling Entertainment championship, losing by disqualification after Nathan attacked Dirge. This occasion marked Nathan Orton's first appearance in a professional wrestling event. In 2009, Orton appeared at the IWC "Night of Legends" event, performing against former rival Jimmy Snuka. Orton was defeated. In 2009, Orton faced Vance Desmond in the 2009 Winter Wrestlefest event, promoted by Canadian Promotion (ASW) Orton lost to Desmond.


title: Bob Orton Jr.

text: In 2010, Orton faced "Bullet" Bob Armstrong for the Juggalo Championship Wrestling "Wrestling Legend & Loonies 2010" event. Orton was defeated by Armstrong despite Orton dominating him most of the match. On November 19, 2011, Orton appeared in the main event of a Holy Havoc Championship Wrestling card in Springfield, Illinois, teaming with HHCW Heavyweight Champion Pretty Boy Floyd and Mr. Allstar Rex Gill to defeat The Irish Revolution (Mickey Thomas and Seamus Farnam) and Beast. On August 25, 2012, Orton appeared at a Wrestling Past Present Future (WPPF) event in East Moline, IL. The match was billed as "Cowboy versus Cowboy" due to Orton's opponent, "Cowboy" Troy Hansen also using the moniker "Cowboy". Orton won by pinfall.


title: Bob Orton Jr.

text: On February 9, 2013, Orton appeared at a Traditional Championship Wrestling (TCW) event in Jonesboro, Ark., where he managed and mentored International Heavyweight Champion "Mr. Saturday Night" Michael Barry in a feud with his cousin "All That" Alan Steel. He also participated in a non-televised dark match at the event when he turned on Barry and aligned himself with "The Empire" consisting of Matt Riviera and "Golden Boy" Greg Anthony. This team took on Michael Barry, Barrett Brown and John Saxon. The Empire along with Orton lost to Barry, Brown, and Saxon. On June 13, 2013, Orton faced Barrett Brown in a losing effort.


title: Bob Orton Jr.

text: On August 16, 2013, Orton and George South faced Tim Horner and Tom Prichard at the Brad Armstrong Memorial event. Orton and South lost to Horner and Prichard. On November 16, 2013, Orton teamed up with former rival Harker Dirge to take on the team of Attitude, Inc., Guy Smith and Spencer Powers, in tag team action at the monthly Pro Wrestling Glory show in Maroa, Illinois. Orton and Dirge won the match. On October 25, 2014, Orton wrestled rival "Spotlight" Spencer Powers for the Pinfall Wrestling Association P.W.A. Heavyweight title at the Jaycee's Center in Springfield, Illinois. Orton was defeated.


title: Bob Orton Jr.

text: On March 21, 2015, Orton participated in a 6-man tag team match teaming with Ricky Cruz and Red River Jack with Nikolai Volkoff as their manager to take on Chris Hargas, Bull Bronson and Attila Khan. Orton's team came victorious. In April 2015, Orton participated in a 2-on-1 handicap match taking on "Iron Man" Ken Kasa & Travis Cook for the St. Louis Wrestling promotion. Orton defeated Kasa and Cook after applying an RKO to Kasa. On May 30, 2015, Orton was the Special Guest of Pinfall Wrestling Association in Springfield, Illinois at their biggest show of the year, The Grand Wrestling Spectacle V. Orton defeated Bradley Stephens III (who was looking for a "Legend" to challenge).


title: Bob Orton Jr.

text: Orton made an appearance on the November 15, 2010 episode of WWE Raw as the show went old school, with appearances from past WWE wrestlers, announcers and other on-air personalities. He also appeared on the April 10, 2012 episode of WWE SmackDown and was attacked by Kane (offscreen) who had been feuding with his son Randy at the time. Orton appeared once again on June 18, 2017 at the Money in the Bank Pay-per-view, situated in the front row of the crowd along with fellow Hall of Famers Ric Flair and Sgt. Slaughter. During the match between his son Randy and Jinder Mahal he would be assaulted by the Singh brothers as they were ejected from ringside, this prompted Randy to attack the Singh brothers. However this distraction proved enough for Jinder to hit Randy with the Khallas for the victory.


title: Bob Orton Jr.

text: Orton is married to Elaine Orton, a nurse at "Christian Hospital NE" in Missouri, and they have two sons, Randy (also a professional wrestler), Nathan (a stand-up comedian), and a daughter, Becky. His first grandchild was born on July 12, 2008, when son Randy and his now ex-wife Samantha had their first child, a daughter, Alanna.


title: Bob Orton Jr.

text: On an episode of "WWE Confidential", he admitted that his forearm injury in the 1985 match with Jimmy Snuka was not a work and did not heal when he wore the cast. It wouldn't heal fully until he left the WWF in 1987.


title: Bob Orton Jr.

text: Around 1986, Orton was involved in an incident in Fresno, California, where the Fresno Police Department were called for an incident involving Orton and Roddy Piper in a hotel. Orton would end up naked and drunk on the roof of the hotel and would be shot three times with police tasers, according to Orton himself.


title: Bob Orton Jr.

text: As a teenager, Orton was diagnosed with hepatitis C, but apparently showed no apparent symptoms and would eventually no longer recall having the disease. Over 30 years later, in the midst of his feud with his son Randy against The Undertaker, Orton was retested and it was confirmed that he still carried the disease. The Undertaker was furious that he was uninformed of Orton's illness and learned that former Head of Talent Relations John Laurinaitis (who knew of Orton's disease) allowed him to blade, as at one point in the feud (during a Hell in a Cell match at Armageddon 2005), Orton spilled blood directly onto him, which could have caused him to contract the disease. This was the main reason Orton was let go by WWE in February 2006.


title: Pancasila (politics)

text: Pancasila () is the official, foundational philosophical theory of Indonesia. The name is made from two words originally derived from Sanskrit: ""pañca"" ("five") and ""śīla"" ("principles", "precepts").


title: Pancasila (politics)

text: In 1942, the Empire of Japan invaded and occupied the Dutch East Indies. Following setbacks in the Pacific War, the Japanese promised future self-government for Indonesia and in September 1943, established the Central Advisory Council (CAC) in Java, chaired by pre-war independence activist Sukarno. On 15 November 1944, at the fourth session of the CAC, Sukarno gave a speech listing five guidelines for life for the Indonesian nation. These had been produced by a committee headed by Sukarno, and were dubbed the "Five Obligations" ("Panca Dharma"). They were:


title: Pancasila (politics)

text: On 1 March 1945, the Japanese 16th Army, which was responsible for Java during the Japanese occupation of the Dutch East Indies, announced the establishment of the Investigating Committee for Preparatory Work for Independence (BPUPK) to work on "preparations for independence in the region of the government of this island of Java." The first session of the BPUPK opened on 28 May 1945, and the following day began discussions on a basis for the future independent Indonesia. A number of speakers put forward proposals, and Wiranatakusumah suggested the "Panca Dharma".


title: Pancasila (politics)

text: On the final day of the first session, Indonesian nationalist Sukarno made a speech, later to become known as the "Birth of Pancasila Address", in which he outlined five principles, which he proposed would form the philosophical basis of an independent Indonesia. His original formulation was:


title: Pancasila (politics)

text: In his speech, Sukarno rejected the "Panca Dharma" as a name, saying that "dharma" meant 'obligation', but that he was proposing principles. He further said that he liked the symbolic meaning of "five" as there were Five Pillars of Islam, five fingers to a hand and five senses. He named the principles "Pancasila".


title: Pancasila (politics)

text: During the recess between the two BPUPK sessions, the Committee of Nine ("Panitia Sembilan"), composed of Sukarno, Mohammad Hatta, Mohammad Yamin, Alexander Andries Maramis, Ahmad Subardjo, Ki Hadikusumo, Wachid Hasyim, Agus Salim, and Abikusno, formulated a preamble to a constitution including Sukarno's philosophy. This became known as the Jakarta Charter. The order of Sukarno's principles was changed, thus: the fifth "sila" of theism and freedom of religion became first "sila"; the second "sila" remained, the original first "sila" was re-numbered as the third "sila", and the original third and fourth "sila" were re-numbered as the fourth and fifth "sila". Sukarno accepted this proposition of the other members. Further, the first "sila" of the Jakarta Charter and the Preamble of the Constitution of Indonesia of 1945, being the first of the original "sila" of Sukarno, was amended to read ""Ketuhanan dengan kewajiban menjalankan syariah Islam bagi pemeluk-pemeluknya"" ("The one divinity with the obligation for its Muslim adherents to carry out the Islamic law/Syari'ah"). On 18 August 1945 the PPKI amended it further by deleting "with the obligation for its Muslim adherents to carry out the Islamic law/Syari'ah" and therefore left the first "sila" as simply "Ketuhanan Yang Maha Esa".


title: Pancasila (politics)

text: By the first half of the 20th century, some ideologies that had been established or made their way to the Dutch East Indies included imperialism and its antithesis anti-colonial nationalism, traditional Javanese statecraft, Islamism, democracy, socialism, and communism. Proponents of these ideologies had formed political organizations or parties to forward their respective causes. The Islamist party Sarekat Islam was established in 1905 followed by Masyumi in 1943. The Communist Party was established in 1914, while Sukarno's nationalist Indonesian National Party was established in 1927. Favoring one ideology over another would not satisfy the whole spectrum of Indonesian people, thus it was decided that the new republic needed to synthesize a new ideology derived from indigenous Indonesian values as well as common shared values derived from various ideologies.


title: Pancasila (politics)

text: In 30 September 1960, Sukarno's speech in United Nations General Assembly XV, Sukarno affirmed that the first "sila" of Pancasila does not aim to persecute those who do not have a religion or are atheists. He said that "the one divinity" in the first "sila" are only characteristics for the nation, accepting the first "sila" not only means tolerating those who have different beliefs, but also to atheists or to people that does not believe in god because they recognize the first "sila" as their nation's characteristics.


title: Pancasila (politics)

text: Pancasila was influenced by certain aspects of selected world values and ideologies, such as nationalism, humanitarianism, individual rights, freedom of religion, democracy, socialism. The need to unify this diverse country also led to the formulation of the national motto, Bhinneka Tunggal Ika, which can be translated as unity in diversity. It declares the essential unity of its members despite ethnic, regional, social, or religious differences.


title: Pancasila (politics)

text: A commander of the 1st Military Regional Command/Bukit Barisan in 1966 described Pancasila as a form of religious socialism.


title: Pancasila (politics)

text: In the campaign for the 1955 legislative election, nationalist parties such as the Indonesian National Party (PNI) and the Communist Party of Indonesia (PKI) used Pancasila in an anti-Islam sense, to distinguish themselves from the Islamic Masyumi Party as they feared that if Masyumi won the election, Islam would replace Pancasila as the basis of the nation. In the Constitutional Assembly, elected in 1955 to produce a permanent constitution to replace the 1950 Provisional Constitution, the parties organized themselves into factions depending on their preference for the national philosophy. The Pancasila Block had 53.3% of the seats, while the Islamic Block had 44.8%. The debate over which should prevail was not resolved through debate as on 5 July 1959, President Sukarno dissolved the assembly by decree and reimposed the 1945 Constitution. As this included the Pancasila formulation, the Pancasila/Islam debate was ended.


title: Pancasila (politics)

text: The New Order administration of Suharto, the second President of Indonesia, strongly supported Pancasila. His government promoted the five principles as a key national ideology. They were outlined as representing the ancient wisdom of the Indonesian people, pre-dating the introduction of foreign religions such as Hinduism and Islam. In a July 1982 speech which reflected his attachment to Javanese beliefs, Suharto glorified Pancasila as a key to reach the perfect life (Javanese: ) of harmony with God and fellow men.


title: Pancasila (politics)

text: In 1978, Suharto secured a parliamentary resolution (Tap MPR No. 2/1978) on the "Pancasila Appreciation and Practicing Guide" ("Pedoman Penghayatan dan Pengamalan Pancasila" or "P4") and later began a mandatory program to indoctrinate all Indonesians—from primary school students to office workers—for the application of the P4 and in living the national values. After initially being careful not to offend the sensitivities of Muslim scholars who feared that the Pancasila might develop into a quasi-religious cult, he secured another parliamentary resolution in 1983 (Tap MPR No. 11/1983) that officially made obedience to Pancasila mandatory to all organizations in Indonesia, public or private. In practice, the administration of Suharto exploited the vagueness of the Pancasila to justify its acts and to condemn opponents as "anti-Pancasila".


title: Pancasila (politics)

text: The International Humanist and Ethical Union (IHEU), an atheist group, has criticized the first "sila" because it does not include a right to atheism, i.e. a rejection of theistic belief. The IHEU argued that this enables a culture of repression against atheists and that, as long as Indonesian law only recognizes the religions of Buddhism, Confucianism, Hinduism, and Islam, as well as both Catholic and Protestant Christianity, people who did not identify with any of them, including atheists, would "continue to experience official discrimination."


title: Pancasila (politics)

text: Criticism of the Pancasila is forbidden by the criminal code because the national emblem of Indonesia includes the Pancasila. According to article 68, its defamation carries a sentence of up to five years imprisonment or half a billion rupiah. In 2018, the controversial Islamic Defenders Front leader Muhammad Rizieq Shihab was charged under 154a and 320 of the Criminal Code on insulting the state ideology and defamation. The charges were later dropped.


title: Pancasila (politics)

text: The points of practice of Pancasila "(Butir-butir pengamalan Pancasila)" is outlined in the People's Consultative Assembly Decree No. 1/MPR/2003.


title: Michael Shea (diplomat)

text: Michael Sinclair MacAuslan Shea, (10 May 1938 – 17 October 2009) was Press Secretary to Queen Elizabeth II from 1978 to 1987. Earlier he had been a career diplomat and was also an author of political thrillers and non-fiction.


title: Michael Shea (diplomat)

text: Until the age of 14 Shea attended Lenzie Academy, where his mother was a teacher. He then attended Gordonstoun as a result of gaining a scholarship. He graduated from the University of Edinburgh, having read Economics; he also completed his doctorate at University of Edinburgh on economic development in West Africa. He was commissioned during his National Service into the Royal Corps of Signals in 1957. He entered the Foreign Service in 1963 and served in Ghana, West Germany, Romania and New York.


title: Michael Shea (diplomat)

text: After helping to arrange the Queen's official visit to the United States Bicentennial celebrations in 1976, Shea became her press secretary two years later. He was at the centre of a "mole hunt" in 1986 for the person who gave a briefing to a journalist on "The Sunday Times" in which it was said that the social policies being followed by the Thatcher government were causing the Queen "dismay", and that Margaret Thatcher's negative attitude to the Commonwealth of Nations caused displeasure. Members of Parliament called for Shea's resignation if he was responsible. The Queen's Private Secretary, Sir William Heseltine, responded to the controversy in a letter to "The Times" confirming Shea as the contact, but asserting that Shea's comments had been misreported.


title: Michael Shea (diplomat)

text: Shea left royal service the following year; some sources indicated that he was "dropped" from the role. He continued to deny that there was any connection with the earlier controversy. He was not knighted but was made a Lieutenant of the Victorian Order (LVO) in 1985 and Commander (CVO) in 1987.


title: Michael Shea (diplomat)

text: While First Secretary in Bonn, then the capital of West Germany, Shea began his career as a writer. A thriller, "Sonntag", was published under the pseudonym Michael Sinclair in 1971, the first of 20 books, most of them political thrillers, some set in the near future. "State of the Nation" (1997) and "Endgame" (2002) take place in an independent Scotland. His memoirs were published as "A View from the Sidelines" (2003).


title: Michael Shea (diplomat)

text: After he resigned as the Queen's press secretary, Shea worked for six years at Hanson plc as director of public relations. He can be heard in a private interview given to Brendan Bruce (former Conservative Party Director of Communications under Margaret Thatcher) for his book "Images of Power" (Kogan Page 1992) in the British Library Sound Archive. Other activities included service with National Galleries of Scotland as a trustee, with the Royal Edinburgh Military Tattoo as a director, and with the Royal Lyceum Theatre as chairman. Shea was also among the group that revived the Edinburgh Oyster Club.


title: Michael Shea (diplomat)

text: Shea was portrayed by Nicholas Farrell in episode 8 of series 4 of "The Crown", in a storyline focusing on apartheid and the alleged rift between Margaret Thatcher and Queen Elizabeth II.


title: Leningrad Oblast

text: Leningrad Oblast (, , ) is a federal subject of Russia (an oblast). It was established on 1 August 1927, although it was not until 1946 that the oblast's borders had been mostly settled in their present position. The oblast was named after the city of Leningrad. In 1991, the city restored its original name, Saint Petersburg, but the oblast retains the name of Leningrad. The capital and largest city is Gatchina.


title: Leningrad Oblast

text: The oblast overlaps the historic region of Ingria and is bordered by Finland (Kymenlaakso and South Karelia) in the northwest and Estonia (Ida-Viru County) in the west, as well as five federal subjects of Russia: the Republic of Karelia in the northeast, Vologda Oblast in the east, Novgorod Oblast in the south, Pskov Oblast in the southwest, and the federal city of Saint Petersburg in the west.


title: Leningrad Oblast

text: The first governor of Leningrad Oblast was Vadim Gustov (in 1996–1998). The current governor, since 2012, is Aleksandr Drozdenko.


title: Leningrad Oblast

text: The oblast has an area of and a population of 1,716,868 (2010 Census); up from 1,669,205 recorded in the 2002 Census. Leningrad Oblast is highly industrialized.


title: Leningrad Oblast

text: Leningrad Oblast is located around the Gulf of Finland and south of two great freshwater lakes, Lake Ladoga and Lake Onega. The oblast includes the Karelian Isthmus and some islands, including Gogland in the Gulf of Finland and Konevets in Lake Ladoga.


title: Leningrad Oblast

text: Much of the area of the oblast belongs to the drainage basin of the Neva, which is the only outflow of Lake Ladoga. The Neva, which flows to the Gulf of Finland (the city of Saint Petersburg is located in its river delta) is relatively short, but its drainage basin is very large, including Lake Onega and Lake Ilmen. The Svir and the Volkhov flow from Lake Onega and Lake Ilmen, respectively, to Lake Ladoga. Other major tributaries of Lake Ladoga include the Vuoksi and the Syas. Rivers in the western part of the oblast flow to the Gulf of Finland; the two biggest rivers there are the Luga and the Narva, which forms the border of Russia and Estonia. Small areas in the east of the oblast lie within the river basin of the Chagodoshcha, a tributary of the Mologa, and of the Suda, both within the Volga basin. A ridgeline in Tikhvinsky District in the eastern oblast forms part of the divide between the Baltic Sea and Caspian Sea basins.


title: Leningrad Oblast

text: The terrain of Leningrad Oblast is relatively flat and mostly covered with forest and swamps. An exception is the rocky Karelian Isthmus, which contains a lake district, as well as the Vepsian Upland in the east. The biggest lakes on the isthmus are Lake Vuoksa, Lake Sukhodolskoye, and Lake Otradnoye.


title: Leningrad Oblast

text: Leningrad Oblast contains two federally protected natural areas, the Nizhnesvirsky Nature Reserve and Mshinskoye Boloto Zakaznik, both created to protect the forest and swamp landscapes of northwestern Russia.


title: Leningrad Oblast

text: The most taxonomically diverse vascular plant families are Asteraceae, Cyperaceae, Poaceae and Rosaceae. By far the most diverse genus is "Carex" (68 species). The diversity in genera "Hieracium" (with "Pilosella"), "Ranunculus" (with "Batrachium"), "Alchemilla", "Galium", "Potamogeton", "Salix", "Veronica", "Viola", "Juncus", "Artemisia", "Potentilla", "Rumex", "Festuca", "Epilobium", "Poa", "Trifolium", "Campanula", "Vicia", "Lathyrus", "Geranium" is also considerable. The territory has no endemic plant taxa. Vascular plant species of Leningrad Oblast listed in the red data book of Russia are "Botrychium simplex", "Cephalanthera rubra", "Cypripedium calceolus", "Epipogium aphyllum", "Lobelia dortmanna", "Myrica gale", "Ophrys insectifera", "Orchis militaris", "Pulsatilla pratensis", "Pulsatilla vernalis".


title: Leningrad Oblast

text: The territory of present-day Leningrad Oblast was populated shortly after the end of the Weichselian glaciation and now hosts numerous archaeological remnants. The Volga trade route and trade route from the Varangians to the Greeks crossed the territory. Staraya Ladoga, the first capital of legendary Rurik, founded in the 8th-9th century, is situated in the east of the oblast, on the Volkhov River.


title: Leningrad Oblast

text: In the 12th-15th centuries, the territory was divided between the Kingdom of Sweden and Novgorod Republic (see Swedish-Novgorodian Wars) and populated mostly by various Baltic Finns people such as Karelians (northwest), Izhorians and Votes (west), Vepsians (east), as well as Ilmen Slavs of Novgorod (south). During the Russo-Swedish Wars of the 15th-17th centuries, the border moved back and forth over the land.


title: Leningrad Oblast

text: The central part of the territory is known as the historical region of Ingria (or the land of Izhora) and in the 17th century, after most of the present-day territory of Leningrad Oblast was captured by Sweden with the Treaty of Stolbovo of 1617, became subject to substantial Finnish Lutheran population influx from Finnish Karelia (which included Karelian Isthmus, the northwestern part of present-day Leningrad Oblast) and Savonia. Having faced religious pressure from Lutheran pastors and Swedish authorities, the local Orthodox population of Russian and Finnic ancestry massively fled from Ingria to neighbour Russian provinces, so Ingrian Finns soon became the dominant ethnic group.


title: Leningrad Oblast

text: During the Great Northern War (1700–1721) the territory of what is now Leningrad Oblast was conquered from Sweden by Russia under Peter the Great, who founded Saint Petersburg amidst the land in 1703, which soon became the capital of the Russian Empire. In 1708, most of the territory was organized into Ingermanland Governorate under Governor General Alexander Menshikov. It was renamed Saint Petersburg Governorate in 1710 (the borders of that governorate, however, differed very significantly from those of the present-day oblast and included much of the areas of current Novgorod, Pskov, and Vologda Oblasts). In 1721, the territorial concessions of Sweden were confirmed with the Treaty of Nystad.


title: Leningrad Oblast

text: The life of the countryside was greatly influenced by the vicinity of the imperial capital, which became a growing market for its agricultural production as well as the main consumer of its mineral and forest resources. In 1719–1810, Ladoga Canal was dug between the Svir River and the Neva River as part of the Volga-Baltic waterway to bypass stormy waters of Lake Ladoga. Since the advent of rail transport in the late 19th century, the areas in the vicinity of Saint Petersburg had been popular summer resort destinations (dachas) for its residents. However, while Saint Petersburg itself was populated mostly by Russians from the very beginning, it was not until the 20th century that its surrounding population was Russified.


title: Leningrad Oblast

text: In 1914, with the beginning of World War I, Saint Petersburg was renamed Petrograd and the governorate was accordingly renamed Petrograd Governorate. After the Russian Revolution, in 1918, the capital was transferred from Petrograd to Moscow, farther from the borders of the country. In 1919, during the Russian Civil War, the Northwestern White Army advancing from Estonia and led by Nikolai Yudenich tried to capture Petrograd and even managed to reach its southern outskirts, but the attack against the Red Army under Leon Trotsky ultimately failed, and Yudenich retreated. The border with Estonia was established in the Russian-Estonian Treaty of Tartu of 1920. Finland-backed Ingrian Finns of North Ingria attempted to secede in 1918–1920, but were incorporated back with the Russian-Finnish Treaty of Tartu, which settled the border between Finland and Soviet Russia. In 1924, Petrograd was renamed Leningrad, and Petrograd Governorate was again renamed accordingly (Leningrad Governorate).


title: Leningrad Oblast

text: Leningrad Oblast was established on 1 August 1927, by the resolutions of the All-Russian Central Executive Committee "On the Establishment of Leningrad Oblast" and "On the Borders and Composition of the Okrugs of Leningrad Oblast" by merging Cherepovets, Leningrad, Murmansk, Novgorod, and Pskov Governorates. The territory of the oblast corresponded to the modern territories of the present-day Leningrad Oblast (with the exception of the Karelian Isthmus and the territories along the border with Estonia), Novgorod Oblast, Pskov Oblast, parts of Vologda Oblast, most of Murmansk Oblast, and the federal city of Saint Petersburg. The total area of the oblast was ; more than four times larger than the modern entity. Administratively, the oblast was divided into nine okrugs (Borovichi, Cherepovets, Leningrad, Lodeynoye Pole, Luga, Murmansk, Novgorod, Pskov, and Velikiye Luki), each of which was in turn subdivided into districts.


title: Leningrad Oblast

text: In 1929, Velikiye Luki Okrug was transferred to newly formed Western Oblast. Leningrad was administratively separated from Leningrad Oblast in December 1931. In 1935 five southernmost districts were made part of Kalinin Oblast. In 1936 some parts of the territory of Leningrad Suburban District of Leningrad was returned to Leningrad Oblast and divided into Vsevolozhsky District, Krasnoselsky District, Pargolovsky District and Slutsky District (renamed Pavlovsky District in 1944). Vologda Oblast, which has included the easternmost districts of Leningrad Oblast (former Cherepovets Governorate), was created in 1937. Murmansk Oblast was split from Leningrad Oblast in 1938.


title: Leningrad Oblast

text: In the autumn of 1934, the Forbidden Border Zone along the western border of the Soviet Union was established, where nobody could appear without special permission issued by the NKVD. It was officially only 7.5 km deep initially, but along the Estonian border it extended to as much as 90 km. The zone was to be cleansed of Finnic and other peoples who were considered "politically unreliable" by the regime. Starting from the 1929, the Soviet authorities carried out mass deportations of the Ingrian Finnish population of the oblast, which constituted the majority in many rural localities as late as in the beginning of the 20th century, to the east, replacing them with people from other parts of the Soviet Union.


title: Leningrad Oblast

text: On 30 November 1939, the Soviet Union waged the Winter War against neighbouring Finland and with the Moscow Peace Treaty in 1940 gained some territories, including the Karelian Isthmus. Their Karelian population was hastily evacuated to inner Finland and later replaced with people from other parts of the Soviet Union. A small part of the territory (the municipalities of Kanneljärvi, Koivisto and Rautu) was incorporated into Leningrad Oblast, the rest being included within the Karelo-Finnish Soviet Socialist Republic.