omniomni/omni-engineering huggingface dataset:
Mahaicony River. The Mahaicony River is a small river in northern Guyana that drains into the Atlantic Ocean.  Mahaicony village is found at the mouth of the river.

Farming and cattle rearing are  the predominant human use of the lower reaches of the river. Sea defenses were built to protect the area from coastline erosion tangent to the river. Spring tides and heavy rains can deteriorate the natural mangrove defenses or man-built dams, which affects nearby settlements of Mahaicony, Content, and Dantzig. There is a koker at Mora Point for diverting water into the Jagdeo canal, and Mahaica-Mahaicony-Abary/-Agricultural Development Authority (MMA/ADA) Phase Two is a proposed conservancy project for additional drainage.

Settlement 
Ninety-six miles up the river is the village of Moraikobai. The river is an important transportation hub for the community.

Esau and Jacob is another riverside settlement.

See also
List of rivers of Guyana
List of rivers of the Americas by coastline

References

Rivers of Guyana
CO2 rocket. {{DISPLAYTITLE:CO2 rocket}}
A carbon dioxide rocket (CO2 rocket) is a type of rocket that uses carbon dioxide as a propellant. It should be fired outdoors.

Carbon dioxide rocket (slurry, hybrid, etc.) can be used in model rocketry, where it is also known as a pop rocket. Its engine could generate a specific impulse of around 280 seconds.

See also
Water rocket

References 

Model rocketry
Model rockets
Power Macintosh 6500. The Power Macintosh 6500 is a personal computer designed, manufactured and sold by Apple Computer from February 1997 to March 1998 as part of the Power Macintosh family. It was introduced with speeds of 225 and 250 MHz, with two faster models at 275 and 300 MHz being added a couple of months later.

The 6500 uses the same "InstaTower" case as the Power Macintosh 6400, and is also internally similar. However, there are some differences apart from the faster processor: The 6500 has no RAM soldered to the logic board (the 6400 had 8 MB, which also explains its higher memory ceiling), and uses a different graphics processor. Models from 250 MHz upward also include video in/out capability, some of them with a hardware-accelerated Avid capture card. Some models also include a Zip drive.  The Power Macintosh 5500 uses the same logic board in a 5200 style all-in-one case.

According to Apple, the Power Macintosh 6500 was the first personal computer to reach . This milestone was announced in conjunction with a three-day "technology fair" from April 4 to 6, 1997 at Walt Disney World, co-hosted by Apple and Disney.

The 6500 was discontinued in March 1998, a few months after the Power Macintosh G3 Mini Tower was introduced.

Models 
Introduced February 17, 1997:
 Power Macintosh 6500/225
 Power Macintosh 6500/250

Introduced April 4, 1997:
 Power Macintosh 6500/275
 Power Macintosh 6500/300

Introduced September 15, 1997:
All machines include a 12× CD-ROM drive and a 33.6 kbit/s modem.
 Power Macintosh 6500/225 Home Edition: 4 GB hard drive.  US$1,600.
 Power Macintosh 6500/250 Home Edition: 4 GB hard drive.  US$2,000.
 Power Macintosh 6500/275 Home Edition: 4 GB hard drive.  US$2,500.
 Power Macintosh 6500/275 Small Business Edition: 4 GB hard drive.  48 MB memory. Internal 100 MB Iomega zip drive. US$2,800.
 Power Macintosh 6500/275 Creative Studio Edition: 4 GB hard drive, 32 MB memory, 512 KB L2 cache, Avid Cinema card, Apple Video System, TV/FM Radio System.
 Power Macintosh 6500/300 Home Edition: 4 GB hard drive.  64 MB memory.  US$3,000.

Timeline

References

External links
The 6400 Zone, a 6400 and 6500-specific resource site
 Power Macintosh 6500 at apple-history.com
 Power Macintosh 6500/225, 6500/250, 6500/275 and 6500/300 at EveryMac.com

6500
6600
Macintosh towers
Computer-related introductions in 1997
Logic Trunked Radio. Logic Trunked Radio (LTR) is a radio system developed in the late 1970s by the E. F. Johnson Company.

LTR is distinguished from some other common trunked radio systems in that it does not have a dedicated control channel. LTR systems are limited to 20 channels (repeaters) per site and each site stands alone (not linked).  is Each repeater has its own controller and all of these controllers are coordinated together. Even though each controller monitors its own channel, one of the channel controllers is assigned to be a master and all the other controllers report to it.

Typically on LTR systems, each of these controllers periodically sends out a data burst (approximately every 10 seconds on LTR Standard systems) so that the subscriber units know that the system is there and which channels are in use or available. The idle data burst can be turned off if desired by the system operator. Some systems will broadcast idle data bursts only on channels used as home channels and not on those used for "overflow" conversations. To a listener, the idle data burst will sound like a short blip of static like someone keyed up and unkeyed a radio within about 1/4 second. This data burst is not sent at the same time by all the channels but happen randomly throughout all the system channels.

References

External links 
Logic Trunked System article from 'Monitoring Times'

E.F. Johnson Company website
LTR description page at the MRA Company Website

 
Radio electronics
Radio resource management
Radio networks
Roger Morris (engineer). Roger Brian Morris (19 March 1933 – 15 June 2001) was a pioneer in railway engineering, having helped develop the rail system for the Channel Tunnel, the hovertrain project as well as a number of the railway systems in Eastern Europe and South America.

Morris was born in Liverpool, England.

In his later years he became a Fellow of Magdalene College, Cambridge.  During those years he functioned as an assistant to students attending the College.  His obituary in The Times described him as "a Cambridge don of an increasingly rare kind, concerned not just with academic results but the development of rounded personalities.  A friendly uncle to waves of students...he taught not only engineering, but how to get the most out of the university, and out of life."

References

1933 births
2001 deaths
British railway civil engineers
Fellows of Magdalene College, Cambridge
Engineers from Liverpool
Dynamics of Markovian particles. Dynamics of Markovian particles (DMP) is the basis of a theory for kinetics of particles in open heterogeneous systems. It can be looked upon as an application of the notion of stochastic process conceived as a physical entity; e.g. the particle moves because there is a transition probability acting on it.

Two particular features of DMP might be noticed: (1) an ergodic-like relation between the motion of particle and the corresponding steady state, and (2) the classic notion of geometric volume appears nowhere (e.g. a concept such as flow of "substance" is not expressed as liters per time unit but as number of particles per time unit).

Although primitive, DMP has been applied for solving a classic paradox of the absorption of mercury by fish and by mollusks. The theory has also been applied for a purely probabilistic derivation of the fundamental physical principle: conservation of mass; this might be looked upon as a contribution to the old and ongoing discussion of the relation between physics and probability theory.

Sources
Bergner—DMP, a kinetics of macroscopic particles in open heterogeneous systems

Dynamics (mechanics)
Markov models
Wehnelt cylinder. A Wehnelt cylinder (also known as Wehnelt cap, grid cap or simply Wehnelt) is an electrode in the electron gun assembly of some thermionic devices, used for focusing and control of the electron beam. It is named after Arthur Rudolph Berthold Wehnelt, a German physicist, who invented it during the years 1902 and 1903. Wehnelt cylinders are found in the electron guns of cathode ray tubes and electron microscopes, and in other applications where a thin, well-focused electron beam is required.

Structure
A Wehnelt cap has the shape of a topless, hollow cylinder. The bottom side of the cylinder has an aperture (through hole) located at its center, with a diameter that typically ranges from 200 to 1200 μm. The bottom face of the cylinder is often made from platinum or tantalum foil.

Operation
A Wehnelt acts as a control grid and it also serves as a convergent electrostatic lens. An electron emitter is positioned directly above the Wehnelt aperture, and an anode is located below the Wehnelt. The anode is biased to a high positive voltage (typically +1 kV to +30 kV) relative to the emitter so as to accelerate electrons from the emitter towards the anode, thus creating an electron beam that passes through the Wehnelt aperture.

The Wehnelt is biased to a negative voltage (typically −200V to −300V) relative to the emitter, which is usually a tungsten filament or Lanthanum hexaboride (LaB6) hot cathode with a V-shaped (or otherwise pointed) tip. This bias voltage creates a repulsive electrostatic field that suppresses emission of electrons from most areas of the cathode.

The emitter tip is positioned near the Wehnelt aperture so that, when appropriate bias voltage is applied to the Wehnelt, a small region of the tip has a net electric field (due to both anode attraction and Wehnelt repulsion) that allows emission from only that area of the tip. The Wehnelt bias voltage determines the tip's emission area, which in turn determines both the beam current and effective size of the beam's electron source.

As the Wehnelt's negative bias voltage increases, the tip's emitting area (and along with it, the beam diameter and beam current) will decrease until it becomes so small that the beam is "pinched" off. In normal operation, the bias is typically set slightly more positive than the pinch bias, and determined by a balance between desired beam quality and beam current.

The Wehnelt bias controls beam focusing as well as the effective size of the electron source, which is essential for creating an electron beam that is to be focussed into a very small spot (for scanning electron microscopy) or a very parallel beam (for diffraction). Although a smaller source can be imaged to a smaller spot, or a more parallel beam, one obvious trade off is a smaller total beam current.

References 

Vacuum tubes
Electrodes
Railway engineering. Railway engineering is a multi-faceted engineering discipline dealing with the design, construction and operation of all types of rail transport systems. It encompasses a wide range of engineering disciplines, including civil engineering, computer engineering, electrical engineering, mechanical engineering, industrial engineering and production engineering. A great many other engineering sub-disciplines are also called upon.

History 
With the advent of the railways in the early nineteenth century, a need arose for a specialized group of engineers capable of dealing with the unique problems associated with railway engineering. As the railways expanded and became a major economic force, a great many engineers became involved in the field, probably the most notable in Britain being Richard Trevithick, George Stephenson and Isambard Kingdom Brunel. Today, railway systems engineering continues to be a vibrant field of engineering.

Subfields 
Mechanical engineering
 Command, control & railway signalling
Office systems design
Data center design
SCADA
Network design
 Electrical engineering
 Energy electrification
Third rail
 Fourth rail
Overhead contact system
 Civil engineering
 Permanent way engineering
 Light rail systems
 On-track plant
 Rail systems integration
 Train control systems
 Cab signalling
 Railway vehicle engineering
 Rolling resistance
 Curve resistance
 Wheel–rail interface
 Hunting oscillation
 Railway systems engineering
 Railway signalling
Fare collection
CCTV
Public address
Intrusion detection
Access control
 Systems integration

Professional organisations 

 In the UK: The Railway Division of the Institution of Mechanical Engineers (IMechE).
 In the US: The American Railway Engineering and Maintenance-of-Way Association (AREMA)
 In the Philippines: Philippine Railway Engineers' Association, (PREA) Inc.
 Worldwide: The Institute of Railway Signal Engineers (IRSE)

See also 

 Association of American Railroads
 Exsecant
 Degree of curvature 
List of engineering topics
List of engineers
 Minimum railway curve radius
 Radius of curvature (applications)
 Track transition curve
 Transition curve

External links
 Institution of Mechanical Engineers - Railway Division
 AAR

References 

 Engineering disciplines
 Rail technologies
Transportation engineering
Control panel (engineering). A control panel is a flat, often vertical, area where control or monitoring instruments are displayed or it is an enclosed unit that is the part of a system that users can access, such as the control panel of a security system (also called control unit).

They are found in factories to monitor and control machines or production lines and in places such as nuclear power plants, ships, aircraft and mainframe computers. Older control panels are most often equipped with push buttons and analog instruments, whereas nowadays in many cases touchscreens are used for monitoring and control purposes.

Gallery

Flat panels

Enclosed control unit

See also 

 Control stand
 Dashboard
 Electric switchboard
 Fire alarm control panel
 Front panel 
 Graphical user interface
 Control panel (computer)
 Dashboard (software) virtual
 Lighting control console
 Mixing console
 Patch board
 Plugboard
 Telephone switchboard

References

Control devices
Engineering, Printing and Manufacturing Union. The Engineering, Printing and Manufacturing Union (EPMU) was the largest private sector trade union in New Zealand. It was formed in 1996 by the merger of the Engineers' Union (EU), the Printing, Packaging and Manufacturing Union (PPMU), and the Communications and Energy Workers' Union (CEWU).

The EPMU represented workers in eleven industries, including:

 Engineering
 Print & Media
 Manufacturing
 Telecommunications
 Timber
 Aviation
 Plastics
 Postal & Logistics
 Petrochemical & Extractive
 Public Services & Infrastructure
 Food

The EPMU had 40,000 members and was affiliated with the New Zealand Council of Trade Unions and the New Zealand Labour Party. It was also an affiliate of the International Federation of Journalists. In October 2015, it merged with the Service & Food Workers Union to form E tū.

References

External links
 EPMU official site.

New Zealand Council of Trade Unions
Trade unions in New Zealand
International Federation of Journalists
Manufacturing trade unions
Trade unions established in 1996
Trade unions disestablished in 2015
Vinylsilane. Vinylsilane refers to an organosilicon compound with chemical formula CH2=CHSiH3. It is a derivative of silane (SiH4).  The compound, which is a colorless gas, is mainly of theoretical interest.

Substituted vinylsilanes
More commonly used than the parent vinylsilane are vinyl-substituted silanes with other substituents on silicon.  In the area of organic synthesis, vinylsilanes are useful intermediates.

In the area of polymer chemistry and materials science, vinyltrimethoxysilane or vinyltriethoxysilane serve as monomers  and coupling agents.

Preparation
Vinylsilanes are often prepared by hydrosilylation of alkynes.  They can be made by the reaction of alkenyl lithium and Grignard reagents with chlorosilanes.  In some cases dehydrogenative silylation is another method.

References

Carbosilanes
Monomers
Vinyl compounds
Merck molecular force field. Merck molecular force field (MMFF) is a family of chemistry force fields developed by Merck Research Laboratories. They are based on the MM3 force field. MMFF is not optimized for one use, such as simulating proteins or small molecules, but tries to perform well for a wide range of organic chemistry calculations. The parameters in the force field have been derived from computational data consisting of approximately 2800 structures spanning a wide range of chemical classes.

The first published force field in the family is MMFF94. A set of molecular structures and the corresponding output of Halgren's MMFF94 implementation is provided at the Computational Chemistry List for validating other MMFF implementations.

One variant of MMFF94 is MMFF94s, which has different out-of-plane bending and dihedral torsion parameters in order to planarize delocalized trigonal nitrogen atoms, e.g. in aniline. The "s" in MMFF94s stands for "static", as MMFF94s better reflects time-averaged geometries than MMFF94.

See also
Comparison of force-field implementations

References

Force fields (chemistry)
CppUnit. CppUnit is a unit testing framework module for the C++ programming language. It allows unit-testing of C sources as well as C++ with minimal source modification. It was started around 2000 by Michael Feathers as a C++ port of JUnit for Windows and ported to Unix by Jerome Lacoste. The library is released under the GNU Lesser General Public License.

The framework runs tests in suites. Test result output is sent to a filter, the most basic being a simple pass or fail count printed out, or more advanced filters allowing XML output compatible with continuous integration reporting systems.

The project has been forked several times. The freedesktop.org version at GitHub, maintained by Markus Mohrhard of the LibreOffice project (which uses CppUnit heavily), was actively maintained until 2020, and is used in Linux distributions such as Debian, Ubuntu, Gentoo and Arch.


See also

List of unit testing frameworks

Further reading

References

External links
   (freedesktop.org version)

C++ libraries
Extreme programming
Freedesktop.org
Unit testing frameworks
SCIF (disambiguation). SCIF is an acronym for Sensitive compartmented information facility, an enclosure protecting United States secrets.

SCIF may also refer to:

 State Compensation Insurance Fund, a California government-owned workers' compensation insurer
 Safari Club International Foundation, the charitable arm of Safari Club International
 Symmetric Communication Interface, a low-level software library for memory and communication handling between a Xeon Phi Coprocessor and its host.
SCI Foundation, a non-profit initiative that works with governments in sub-Saharan African countries to develop sustainable programmes against parasitic worm infections

See also
 Skiff (disambiguation)
Microsoft FlexGo. FlexGo was a technology developed by Microsoft to enable users to pay for using a full-featured personal computer based on the amount of time it used for, similar to pay as you go for cell phones. Another method of payment was a monthly subscription.  It was introduced on May 21, 2006. IBM and other corporations were also adapting similar business models to expand into new markets. Microsoft began offering a Windows Vista based version of FlexGo in 2008. 

FlexGo had two computing models, a pay-as-you-go model, and a subscription based model. Users would get full access to their PC once they paid. The PC would inform users as their time ran out, and would lock the user out if they did not pay to extend their time.

Goals
FlexGo's main target audience was those in third world countries or people with unsteady income. It had been featured under a topic on Leo Laporte's This Week in Tech, Episode 57 "Vloggercon". 

Microsoft wanted to give people the opportunity to buy their very first computer using FlexGo, and pay for only the time they would use it. Microsoft also planned to team up with telecommunication companies to allow internet access to become a pay as you go feature. The main targeted areas for FlexGo are India, Hungary, Vietnam, Slovenia, and Brazil.

See also
 Pisonet, a type of vending machine in the Philippines which offers time-limited computer and internet access for a small fee

References

External links
FlexGo Technology
Microsoft Original License
Microsoft Pitches Pay-as-you-go PCs
Microsoft Brings Vista To Developing World PCs

Microsoft initiatives
Equivalent temperature. In atmospheric science, equivalent temperature is the temperature of air in a parcel from which all the water vapor has been extracted by an adiabatic process. 

Air contains water vapor that has been evaporated into it from liquid sources (lakes, sea, etc...). The energy needed to do that has been taken from the air. Taking a volume of air at temperature  and mixing ratio of  , drying it by condensation will restore energy to the airmass. This will depend on the latent heat release as: 

where:
  : latent heat of evaporation (2400 kJ/kg at 25°C to 2600 kJ/kg at −40°C)
  : specific heat at constant pressure for air (≈ 1004 J/(kg·K)) 

Tables exist for exact values of the last two coefficients.

See also 
 Wet-bulb temperature
 Potential temperature
 Atmospheric thermodynamics
 Equivalent potential temperature

Bibliography
 M Robitzsch, Aequivalenttemperatur und Aequivalentthemometer, Meteorologische Zeitschrift, 1928, pp. 313-315.
 M K Yau and R.R. Rogers, Short Course in Cloud Physics, Third Edition, published by Butterworth-Heinemann, January 1, 1989, 304 pages.  
 J.V. Iribarne and W.L. Godson, Atmospheric Thermodynamics, published by D. Reidel Publishing Company, Dordrecht, Holland, 1973, 222 pages

Atmospheric thermodynamics
Atmospheric temperature
Meteorological quantities
Emotion-sensitive software. Emotion-sensitive software (ESS) is software specifically designed to target and monitor emotional response in a human being. Some software measures anger by comparing the pitch of a voice to a regular, or calm, pitch. Another approach is the measurement of physical appearance. If a camera or similar recording device picks up a certain amount of red pigmentation in the skin the system can be alerted that this person is angered.

The competitive landscape in the Electronic Surveillance Software (ESS) industry is marked by a high level of secrecy regarding the operational details of these software systems. Many producers deliberately withhold information about the inner workings of their ESS products, a strategy that serves dual purposes: firstly, it intensifies competition among companies in the sector, as each strives to maintain a unique edge without revealing trade secrets that could be leveraged by competitors; secondly, this secrecy acts as a deterrent against individuals or entities who might try to circumvent the surveillance mechanisms.

One application of ESS was developed by University of Notre Dame Assistant Professor of Psychology Sidney D'Mello, Art Graesser from the University of Memphis and a colleague from Massachusetts Institute of Technology. They used the technology to create an electronic tutor that could assess a student's level of boredom and frustration based on facial expression and body language, and react accordingly.

References

Human–computer interaction
Affective computing
Robert A. Gearheart. Robert A. (Bob) Gearheart (born 1938) is an emeritus professor of environmental engineering at Cal Poly Humboldt, in Arcata, California.

Gearheart teaches courses in environmental impact assessment, hazardous waste management, water quality management, and Capstone.

His research interests include water and wastewater treatment, using appropriate technology, including constructed wetlands. He is also involved with a number of public and private sector agencies providing support for water supply facilities in developing countries, such as Indonesia, Kenya, Ghana, and Sierra Leone.

Gearheart is involved with the development of Arcata's Integrated Wetland and Wastewater Treatment Facility and the Arcata Marsh. The Arcata Marsh serves as a sewage treatment plant, a recreation area, a wildlife sanctuary and aquaculture project.

Gearheart received his B.A. in biology and mathematics from the University of North Texas, and his M.S. and Ph.D. in civil engineering from the University of Oklahoma.

References

External links
On-line workshop (broken link) with Bob Gearheart and Greg Gearheart (broken link)
The Sustainability Paradigm Dance Presentation by Bob Gearheart 
Emeritus web page

Environmental engineers
1938 births
Living people
University of Oklahoma alumni
University of North Texas alumni
California State Polytechnic University, Humboldt faculty
People from Arcata, California
Engineers from California