omniomni/omni-engineering huggingface dataset:
Ludvig Lorenz. Ludvig Valentin Lorenz ( ; 18 January 1829 – 9 June 1891) was a Danish physicist and mathematician. He developed mathematical formulae to describe phenomena such as the relation between the refraction of light and the density of a pure transparent substance, and the relation between a metal's electrical and thermal conductivity and temperature (Wiedemann–Franz–Lorenz law).

Biography
Lorenz was born in Helsingør and studied at the Technical University in Copenhagen. He became professor at the Military Academy in Copenhagen 1876. From 1887, his research was funded by the Carlsberg Foundation. He investigated the mathematical description for light propagation through a single homogeneous medium and described the passage of light between different media. The formula for the mathematical relationship between the refractive index and the density of a medium was published by Lorenz in 1869 and by Hendrik Lorentz (who discovered it independently) in 1878 and is therefore called the Lorentz–Lorenz equation. Using his electromagnetic theory of light he stated what is known as the Lorenz gauge condition, and was able to derive a correct value for the velocity of light. He also developed a theory of light scattering, publishing it in Danish in 1890 and in French in his Collected Works, published in 1898. It was later independently rediscovered by Gustav Mie in 1908, so it is sometimes referred to as Lorenz–Mie theory. Additionally, Lorenz laid the foundations for ellipsometry by using Fresnel's theory of refraction to discover that light reflected by a thin transition layer between two media becomes elliptically polarized.

References

External links 
 Scienceworld
 Cartage.org.lb
 "Sur la lumière réfléchie et réfractée par une sphère transparente" pp. 405-529, Œuvres scientifiques de L. Lorenz, Volume 1
 "Modern Electrodynamics" pp. 789-790

1829 births
1891 deaths
People from Helsingør
19th-century Danish mathematicians
Danish physicists
Optical physicists
Available water capacity. Available water capacity is the amount of water that can be stored in a soil profile and be available for growing crops. It is also known as available water content (AWC), profile available water (PAW) or total available water (TAW).

The concept, put forward by Frank Veihmeyer and Arthur Hendrickson, assumed that the water readily available to plants is the difference between the soil water content at field capacity () and permanent wilting point (): 

θa ≡ θfc − θpwp

Daniel Hillel criticised that the terms FC and PWP were never clearly defined, and lack physical basis, and that soil water is never equally available within this range. He further suggested that a useful concept should concurrently consider the properties of plant, soil and meteorological conditions.
 
Lorenzo A. Richards remarked that the concept of availability is oversimplified. He viewed that: the term availability involves two notions: (a) the ability of plant root to absorb and use the water with which it is in contact and (b) the readiness or velocity with which the soil water moves in to replace that which has been used by the plant.

Plant available water in sandy soils can be increased by the presence of sepiolite clay

See also
 Field capacity
 Integral energy
 Nonlimiting water range
 Permanent wilting point

References

Agricultural soil science
Water
Agrometeorology
Nonlimiting water range. The non-limiting water range (NLWR) represents the range of water content in the soil where limitations to plant growth (such as water potential, air-filled porosity, or soil strength) are minimal. John Letey (1985) from UC Riverside introduced the NLWR concept in an attempt to integrate several physical properties associated with plant or root growth to refine the concept of available water capacity. Alvaro Pires da Silva, Bev Kay, and Ed Perfect (University of Guelph, Ontario) (1994) refined the concept and termed it least limiting water range (LLWR).

The upper limit (wet end) of LLWR is determined not only by water content at field capacity (FC), but also the capability of providing adequate aeration for plant roots (usually taken as a minimum air filled porosity of  10%). The upper limit is then defined as:

min q {air filled porosity = 0.1, FC}.

Rather than air-filled porosity at 10%, LaoSheng Wu from UC Riverside proposed moisture content where Oxygen gas diffusion rate ODR value of 0.2 micro-g/cm2/min as criteria for satisfactory aeration status.

The lower limit (dry end) is not only limited to permanent wilting point (PWP) but also the ability of root penetration. This is measured as soil mechanical resistance taken at an arbitrary value, say penetration at 3 MPa.
The lower limit is defined as:

max q {mechanical resistance = 3 MPa, PWP}.

See also
Integral energy
Irrigation scheduling
Limiting factor
Moisture equivalent
Moisture stress
Pedotransfer function
Soil plant atmosphere continuum

References
 Da Silva A P, Kay B D and Perfect E 1994 Characterization of the least limiting water range of soils. Soil Sci. Soc. Am. J. 58, 1775-1781.
 Letey J 1985 Relationship between soil physical properties and crop production. Adv. Soil Sci. 1, 277-294.

Soil physics
Isopycnic. An isopycnic surface is a surface of constant density inside a fluid. Isopycnic surfaces contrast with isobaric or isothermal surfaces, which describe surfaces of constant pressure and constant temperature respectively.
Isopycnic surfaces are sometimes referred to as "iso-density" surfaces, although this is strictly incorrect.
Isopycnic typically describes surfaces, not processes.
Unless there is a flux of mass into or out of a control volume, a process which occurs at a constant density also occurs at a constant volume and is called an isochoric process and not an isopycnic process.

The term "isopycnic" is commonly encountered in the fluid dynamics of compressible fluids, such as in meteorology and geophysical fluid dynamics, astrophysics, or the fluid dynamics of explosions or high Mach number flows.It may also be applied to other situations where a continuous medium has smoothly varying density, such as in the case of an inhomogeneous colloidal suspension. In general isopycnic surfaces will occur in fluids in hydrostatic equilibrium coinciding with equipotential surfaces formed by gravity.

The term "isopycnic" is also encountered in biophysical chemistry, usually in reference to a process of separating particles, subcellular organelles, or other substances on the basis of their density.
Isopycnic centrifugation refers to a method wherein a density gradient is either pre-formed or forms during high speed centrifugation.
After this gradient is formed particles move within the gradient to the position having a density matching their own (this is in fact an incorrect description of the exact physical process but does describe the result in a meaningful way).
This technique is extremely powerful.

In geology, isopycnic surfaces occur especially in connection with cratons which are very old geologic formations at the core of the continents, little affected by tectonic events. These formations are often known as shields or platforms. These formations are, relative to other lithospheric formations, cooler and less dense but much more isopycnic.

References

See also
isopycnic centrifugation
 Isosteric

Atmospheric dynamics
Tectonics
Integral energy. Integral energy is the amount of energy required to remove water from soil with an initial water content  to water content of  (where ). It is calculated by integrating the water retention curve, soil water potential  with respect to :

It is proposed by Minasny and McBratney (2003) as alternative to available water capacity. (AWC)
The AWC concept assumes equal availability of water between two potentials and does not consider the path along the water retention curve. Integral energy takes into the account the path or energy (characterised by water retention curve) required to dry a soil at particular soil moisture content

See also
Available water capacity
Nonlimiting water range

References
Minasny, B., McBratney, A.B., 2003. Integral energy as a measure of soil-water availability. Plant and Soil 249(2), 253-262.

Soil physics
BURS. BURS (bottom-up rewrite system) theory tackles the problem of taking a complex expression tree or intermediate language term and finding a good translation to machine code for a particular architecture. Implementations of BURS often employ dynamic programming to solve this problem.

BURS can also be applied to the problem of designing an instruction set for an application-specific instruction set processor.

References
A. V. Aho, M. Ganapathi, and S. W. K. Tjiang. Code generation using tree matching and dynamic programming. ACM Transactions on Programming Languages and Systems, 11(4):491-516, October 1989.
Robert Giegerich and Susan L. Graham, editors. Code Generation - Concepts, Tools, Techniques. Workshops in Computing. Springer-Verlag, Berlin, Heidelberg, New York, 1992.

External links
https://strategoxt.org/Transform/BURG - short description of BURG including additional references to BURS and BURG

Computer languages
DO-232. DO-232 is an air traffic control software standard published by RTCA, Incorporated.

Flight Information Services (FIS) is defined as the non-control information needed by pilots to operate in the US National Airspace System (NAS) and internationally.  The timely, efficient exchange of FIS data is required for safety, efficiency and utility in aircraft operations.  Pilots, flight planners (e.g., pilots, dispatchers, schedulers), and controllers all need accurate, timely FIS data to plan (or re-plan) and assess the execution of flight operations.

Outline of contents
Introduction
FIS Data Link - Concepts and Needs
FIS Data Link in the FANS CNS/ATM Environment
System Architecture and Implementation Considerations
Current FIS Data Link Products and Plans
Summary and Recommendations
Appendix A: The National Aviation Weather Users Forum
Appendix B: Operational Descriptions of Initial FIS Request/Reply Data Link Products
Appendix C: Additional Details of Some of the Various Candidate Airborne Data Link Channels
Appendix D: Analysis Criteria - SAMA Preliminary Study

See also
Air traffic control
ACARS
Flight Information and Control of Operations

RTCA standards
Air traffic control
Annealing (glass). Annealing is a process of slowly cooling hot glass objects after they have been formed, to relieve residual internal stresses introduced during manufacture. Especially for smaller, simpler objects, annealing may be incidental to the process of manufacture, but in larger or more complex products it commonly demands a special process of annealing in a temperature-controlled kiln known as a lehr. Annealing of glass is critical to its durability. Glass that has not been properly annealed retains thermal stresses caused by quenching, which will indefinitely decrease the strength and reliability of the product. Inadequately annealed glass is likely to crack or shatter when subjected to relatively small temperature changes or to mechanical shock or stress. It even may fail spontaneously.

To anneal glass, it is necessary to heat it to its annealing temperature, at which its viscosity, η, drops to 1013 Poise (1013 dyne-second/cm2). For most kinds of glass, this annealing temperature is in the range of , and is the so-called stress-relief point or annealing point of the glass. At such a viscosity, the glass is still too hard for significant external deformation without breaking, but it is soft enough to relax internal strains by microscopic flow in response to the intense stresses they introduce internally. The piece then heat-soaks until its temperature is even throughout and the stress relaxation is adequate. The time necessary for this step varies depending on the type of glass and its maximum thickness. The glass then is permitted to cool at a predetermined rate until its temperature passes the strain point (η = 1014.5 Poise), below which even microscopic internal flow effectively stops and annealing stops with it. It then is safe to cool the product to room temperature at a rate limited by the heat capacity, thickness, thermal conductivity, and thermal expansion coefficient of the glass. After annealing is complete the material can be cut to size, drilled, or polished without risk of its internal stresses shattering it.

At the annealing point (η = 1013 Poise), stresses relax within several minutes, while at the strain point (η = 1014.5 Poise) stresses relax within several hours. Stresses acquired at temperatures above the strain point, and not relaxed by annealing, remain in the glass indefinitely and may cause either short-term or much delayed failure. Stresses resulting from cooling too rapidly below the strain point largely are considered temporary, although they may be sufficient to cause short-term failure.

See also
For other important temperatures in glass processing, see viscous liquid
Annealing (metallurgy)
Bologna bottle
Fabrication and testing (optical components)
Float glass
Tempered glass
Warm glass

References

Glass engineering and science
Glass production
Warm glass
Firing techniques
Input shaping. In control theory, input shaping is an open-loop control technique for reducing vibrations in computer-controlled machines. The method works by creating a command signal that cancels its own vibration. That is, a vibration excited by previous parts of the command signal is cancelled by vibration excited by latter parts of the command. Input shaping is implemented by convolving a sequence of impulses, known as an input shaper, with any arbitrary command. The shaped command that results from the convolution is then used to drive the system. If the impulses in the shaper are chosen correctly, then the shaped command will excite less residual vibration than the unshaped command. The amplitudes and time locations of the impulses are obtained from the system's natural frequencies and damping ratios. Shaping can be made very robust to errors in the system parameters.

References

External links
 Input shaping simulator demonstrates the filter principle on a gantry crane control problem.

Control theory
Cybernetics
Dynamics (mechanics)
Mechanical vibrations
David Urie. Prior to June 2007, David Urie was Vice-President and Program Manager of Rocketplane Limited, Inc., where he managed the design of the Rocketplane XP.

Prior to joining the Rocketplane team, Urie served as president of Concept Fusion, Inc., providing technical development services to established companies and start-up organizations. During his 30-year career with the Lockheed Martin Corporation, Urie led teams on Lockheed’s X-30 National Aerospace Plane and the HL-20 Personnel Launch System. He was Chief Engineer and then Program Manager of the SR-71 Blackbird reconnaissance system before initiating and heading the Single Stage to Orbit (SSTO) and X-33 Reusable Launch Vehicle (RLV) Programs at Lockheed. Urie's work as the program manager for the previously classified Have Region project demonstrated that rocket-powered single-stage-to-orbit vehicles were technically feasible, which led to the Lockheed Martin SSTO design approach.

As a Director of the Lockheed-Martin Skunk Works SSTO/RLV Advanced Technology Demonstration Program, Urie conceived and developed the aerospike rocket propelled lifting body that was selected by NASA as winner of the X-33 competition. He holds the patent on the design(), and he formed and headed a multi-company team encompassing all aspects of SSTO/RLV.

Urie was also Program Manager for the Trans-Atmospheric Vehicle (TAV) at Lockheed. His team built and successfully tested a large-scale cross section Mach 25 structure. He served on several advanced development projects in Flight Sciences and Operations Analysis.

Throughout his distinguished career, Urie has received numerous honors and awards, including the prestigious Engineer of the Year award from the American Institute of Aeronautics and Astronautics. He has published many articles, prepared and taught several short courses, given various lectures and presentations, and served as aerospace engineering curricula advisor to two universities.

See also
 Gene Salvay - colleague of Urie on the TAV at Lockheed
 Vince Weldon - also assisted on the TAV and X-33

References 

Living people
American aerospace engineers
Year of birth missing (living people)
Grammar-oriented programming. Grammar-oriented programming (GOP) and Grammar-oriented Object Design (GOOD) are good for designing and creating a domain-specific programming language (DSL) for a specific business domain.

GOOD can be used to drive the execution of the application or it can be used to embed the declarative processing logic of a context-aware component (CAC) or context-aware service (CAS). GOOD is a method for creating and maintaining dynamically reconfigurable software architectures driven by business-process architectures. The business compiler was used to capture business processes within real-time workshops for various lines of business and create an executable simulation of the processes used.

Instead of using one DSL for the entire programming activity, GOOD suggests the combination of defining domain-specific behavioral semantics in conjunction with the use of more traditional, general purpose programming languages.

See also
Adaptive grammar
Definite clause grammar
Extensible programming
Language-oriented programming
Dialecting
Transformation language

External links
 Manners Externalize Semantics for On-demand Composition of Context-aware Services
 "Empowering the Business Analyst for On-demand Computing"  for an example of using GOOD.

Domain-specific programming languages
Bis-HPPP. Bis-HPPP (2,2-bis[4(2,3-hydroxypropoxy)phenyl]propane) is an organic compound that is formed when the dental composite material bis-GMA is degraded by salivary esterases. It is also called BADGE·2H2O in reference to it being the hydrolyzed form of BADGE, which is used in the formation of epoxy resins. Structurally, it is a di-ether of bisphenol A.

Formation 
Together with methacrylic acid, bis-HPPP is released following the CE-catalyzed hydrolysis of 2,2-[4(2-hydroxy 3-methacryloxypropoxy)-phenyl]propane (bis-GMA). This reaction is very common in hydrolytic degradation of the dental resin since salivary esterases are able to cleave the ester bonds in acrylic polymers of dental composites.

Analysis by mass spectrometry demonstrated that hydrolytic reactions would cleave the ester bonds of both methacrylate units in bis-GMA and produce bis-HPPP along with two molecules of methacrylic acid.

References

Polyols
Phenol ethers
2,2-Bis(4-hydroxyphenyl)propanes
List of aircraft carriers in service by configuration. The list of aircraft carriers by configuration contains active aircraft carriers organized by the specific configuration of aircraft carrier designs. This list excludes seaplane carriers or helicopter carriers.

Carrier configurations 
There are three main configurations of aircraft carrier in service in the worlds navies:
 Catapult Assisted Take-Off Barrier Arrested Recovery (CATOBAR)
 Short Take-Off Barrier Arrested Recovery (STOBAR)
 Short Take-Off Vertical Landing (STOVL)

Navies with CATOBAR carriers 
 French Navy
 
 United States Navy
 
 
 
 
 
 
 
 
 
 
 
  *(equipped with EMALS)
  *

Navies with STOBAR carriers 
 Chinese Navy
 Type 001 - Modified 
 Liaoning
 Type 002 - Modified 
 Shandong
 Indian Navy
 Modified 
 INS Vikramaditya
 
 
 Russian Navy
 
 RFS Admiral Kuznetsov

Navies with STOVL carriers 
 Italian Navy
 ITS Cavour
 ITS Trieste
 Japan Maritime Self-Defense Force
 
 
 
 Royal Navy
 Queen Elizabeth class
 
 
 Spanish Navy
 
 SNS Juan Carlos I
 Turkish Navy
 
 
 United States Navy

See also
 List of amphibious warfare ships
 List of aircraft carriers
 List of aircraft carriers in service
 Timeline for aircraft carrier service
 List of aircraft carriers by country
 Helicopter Carrier

References

Type
Process function. In thermodynamics, a quantity that is well defined so as to describe the path of a process through the equilibrium state space of a thermodynamic system is termed a process function, or, alternatively, a process quantity, or a path function. As an example, mechanical work and heat are process functions because they describe quantitatively the transition between equilibrium states of a thermodynamic system.

Path functions depend on the path taken to reach one state from another. Different routes give different quantities. Examples of path functions include work, heat and arc length.  In contrast to path functions, state functions are independent of the path taken. Thermodynamic state variables are point functions, differing from path functions. For a given state, considered as a point, there is a definite value for each state variable and state function.

Infinitesimal changes in a process function  are often indicated by  to distinguish them from infinitesimal changes in a state function  which is written . The quantity  is an exact differential, while  is not, it is an inexact differential. Infinitesimal changes in a process function may be integrated, but the integral between two states depends on the particular path taken between the two states, whereas the integral of a state function is simply the difference of the state functions at the two points, independent of the path taken.

In general, a process function  may be either holonomic or non-holonomic. For a holonomic process function, an auxiliary state function (or integrating factor)  may be defined such that  is a state function. For a non-holonomic process function, no such function may be defined. In other words, for a holonomic process function,  may be defined such that  is an exact differential. For example, thermodynamic work is a holonomic process function since the integrating factor  (where  is pressure) will yield exact differential of the volume state function . The second law of thermodynamics as stated by Carathéodory essentially amounts to the statement that heat is a holonomic process function since the integrating factor  (where  is temperature) will yield the exact differential of an entropy state function .

References

See also
Thermodynamics

Thermodynamics