omniomni/omni-engineering huggingface dataset:
Multivariate optical element. A multivariate optical element (MOE), is the key part of a multivariate optical computer; an alternative to conventional spectrometry for the chemical analysis of materials.

It is helpful to understand how light is processed in a multivariate optical computer, as  compared to how it is processed in a spectrometer. For example, if we are studying the composition of a powder mixture using diffuse reflectance, a suitable light source   is directed at the powder mixture and light is collected, usually with a lens, after it has scattered from the powder surface. Light entering a spectrometer first strikes a device (either a grating or interferometer) that separates light of different wavelengths to be measured. A series of independent measurements is used to estimate the full spectrum of the mixture, and the spectrometer renders a measurement of the spectral intensity at many wavelengths. Multivariate statistics can then be applied to the spectrum produced.

In contrast, when using  multivariate optical computing, the light entering the instrument strikes an application specific multivariate optical element, which is uniquely tuned to the pattern that needs to be measured using multivariate analysis.

This system can produce the same result that multivariate analysis of a spectrum would produce. Thus, it can generally produce the same accuracy as laboratory grade spectroscopic systems, but with the fast speed inherent with a pure, passive, optical computer. The multivariate optical computer makes use of optical computing to realize the performance of a full spectroscopic system using traditional multivariate analysis. A side benefit is that the throughput and efficiency of the system is higher than conventional spectrometers, which increases the speed of analysis by orders of magnitude.

While each chemical problem presents its own unique challenges and opportunities, the design of a system  for a specific analysis is complex and requires the assembly of several pieces of a spectroscopic puzzle. The data necessary for a successful design are spectral characteristics of light sources, detectors and a variety of optics to be used in the final assemblage, dispersion characteristics of the materials used in the wavelength range of interest, and a set of calibrated sample spectra for pattern-recognition-based analysis. With these pieces assembled, suitable application specific multivariate optical computer designs can be generated and the performance accurately modeled and predicted.

See also
Optical computer

References
 
 
 
Spectroscopy
Direct-buried cable. Direct-buried cable (DBC) is a kind of communications or transmissions electrical cable which is especially designed to be buried under the ground without any other cover, sheath, or duct to protect it.

Most direct-buried cable is built to specific tolerances to heat, moisture, conductivity, and soil acidity. Unlike standard telecommunications and power cables, which have only a thin layer of insulation and a waterproof outer cover, DBC consists of multiple layers of heavy metallic-banded sheathing, reinforced by heavy rubber covers, shock absorbing gel, wrapped thread-fortified waterproof tape, and stiffened by a heavy metal core.

DBC is preferable in some areas since it is more resistant to being the focus of lightning discharges.

Communications 

Most cable of this kind is coaxial or bundled fiber-optic cable. In the 20th century much of it was filled cable. Direct-buried cable is cheaper and easier to lay than other kinds of cable that require protection from the earth. However, DBC is also easily cut during digging or other excavations. As a result, most direct-buried cable is found on side roads, not main thoroughfares.

Power 
Some power cabling is also direct-buried. This kind of cabling must follow strict regulatory procedures regarding installation  and backfilling. This is usually used for undergrounding in areas where overhead cabling is impractical or dangerous.

See also
 Undergrounding

References

External links 
 Guide to direct buried cabling procedures

Cables
Outline of industrial machinery. The following outline is provided as an overview of and topical guide to industrial machinery:

Essence of industrial machinery 
 Heavy equipment
 Hardware
 Industrial process
 Machine
 Machine tool
 Tool

Industrial machines 
 Agricultural equipment
 Assembly line
 Industrial robot
 Oil refinery
 Packaging and labeling
 Paper mill
 Sawmill
 Smelter
 Water wheel

Industrial processes 
 Bessemer process
 Food processing
 Manufacturing
 Mining
 Packaging and labeling

History of industrial machinery 
 History of agricultural machinery
 History of assembly lines
 History of the bessemer process
 History of heavy equipment
 History of industrial robots
 History of machines
 History of machine tools
 History of oil refineries
 History of packaging and labeling
 History of paper mills
 History of smelting
 History of water wheels

See also 
 Outline of industry

External links 

Industrial machinery
Industrial machinery
 
Industry-related lists
Table of thermodynamic equations. Common thermodynamic equations and quantities in thermodynamics, using mathematical notation, are as follows:

Definitions 

Many of the definitions below are also used in the thermodynamics of chemical reactions.

General basic quantities

General derived quantities

Thermal properties of matter

Thermal transfer

Equations 

The equations in this article are classified by subject.

Thermodynamic processes

Kinetic theory

Ideal gas

Entropy 

 , where kB is the Boltzmann constant, and Ω denotes the volume of macrostate in the phase space or otherwise called thermodynamic probability.
 , for reversible processes only

Statistical physics

Below are useful results from the Maxwell–Boltzmann distribution for an ideal gas, and the implications of the Entropy quantity. The distribution is valid for atoms or molecules constituting ideal gases.

Corollaries of the non-relativistic Maxwell–Boltzmann distribution are below.

Quasi-static and reversible processes 

For quasi-static and reversible processes, the first law of thermodynamics is:
 
where δQ is the heat supplied to the system and δW is the work done by the system.

Thermodynamic potentials 

The following energies are called the thermodynamic potentials,
 
and the corresponding fundamental thermodynamic relations or "master equations" are:

Maxwell's relations 

The four most common Maxwell's relations are:

More relations include the following.

Other differential equations are:

Quantum properties 

 
   Indistinguishable Particles
where N is number of particles, h is that Planck constant, I is moment of inertia, and Z is the partition function, in various forms:

Thermal properties of matter

Thermal transfer

Thermal efficiencies

See also 

 List of thermodynamic properties
 Antoine equation
 Bejan number
 Bowen ratio
 Bridgman's equations
 Clausius–Clapeyron relation
 Departure functions
 Duhem–Margules equation
 Ehrenfest equations
 Gibbs–Helmholtz equation
 Phase rule
 Kopp's law
 Noro–Frenkel law of corresponding states
 Onsager reciprocal relations
 Stefan number
 Thermodynamics
 Timeline of thermodynamics
 Triple product rule
 Exact differential

References 

 Atkins, Peter and de Paula, Julio  Physical Chemistry, 7th edition, W.H. Freeman and Company, 2002 .
 Chapters 1–10, Part 1: "Equilibrium".
 
 Landsberg, Peter T.  Thermodynamics and Statistical Mechanics. New York: Dover Publications, Inc., 1990. (reprinted from Oxford University Press, 1978).
 Lewis, G.N., and Randall, M., "Thermodynamics", 2nd Edition, McGraw-Hill Book Company, New York, 1961.
 Reichl, L.E., A Modern Course in Statistical Physics, 2nd edition, New York: John Wiley & Sons, 1998.
 Schroeder, Daniel V. Thermal Physics.  San Francisco: Addison Wesley Longman, 2000 .
 Silbey, Robert J., et al. Physical Chemistry, 4th ed. New Jersey: Wiley, 2004.
 Callen, Herbert B. (1985). Thermodynamics and an Introduction to Themostatistics, 2nd edition, New York: John Wiley & Sons.

External links 
 Thermodynamic equation calculator

Thermodynamic equations
Thermodynamics
Chemical engineering
STklos. STklos is a Scheme implementation that succeeded STk. It is a bytecode compiler with an ad hoc virtual machine which aims to be fast as well as light.

STklos is free software, released under the GNU General Public License.

In addition to implementing most of R5RS, and a large part of R7RS, STklos supports:
 an object system based on CLOS with multiple inheritance, generic functions, multimethods and a MOP
 a module system
 easy connection with the GTK toolkit
 a low-level macro system that compiles macro expanders into bytecode (syntax-rules is also present as a high-level macro system)
 a full Numerical tower implementation, as defined in R7RS
 Unicode support
 Perl compatible regular expressions via PCRE library
 a simple foreign function interface via libffi
 being compiled as a library and embedded in an application
 native threads, using the  libpthread library. The API conforms to SRFI-18
 a number of SRFIs
 easy access to SLIB
 an HTTP client

References

External links
 STklos home page
 STklos documentation

Scheme (programming language) interpreters
Scheme (programming language) implementations
Chez Scheme. Chez Scheme is a programming language, a dialect and implementation of the language Scheme which is a type of Lisp. It uses an incremental native-code compiler to produce native binary files for the x86 (IA-32, x86-64), PowerPC, SPARC, and AArch64 processor architectures.

History
The first version of Chez Scheme was developed by R. Kent Dybvig and completed in 1984.  Some copies of the original version were distributed in 1985.

Cadence Research Systems developed Chez Scheme until the company was purchased by Cisco Systems in 2011.  Cisco open-sourced Chez Scheme in 2016.

It has supported the R6RS standard since version 7.9.1. It is free and open-source software released under an Apache License, version 2.0. It was first released in 1985, by R. Kent Dybvig, originally licensed as proprietary software, and then released as open-source software on GitHub on 2016-05-13 with version 9.4.

Petite Chez Scheme
Petite Chez Scheme is a sibling implementation which uses a threaded interpreter design instead of Chez Scheme's incremental native-code compiler. Programs written for Chez Scheme run unchanged in Petite Chez Scheme, as long as they do not depend on using the compiler (for example foreign function interface is only available in the compiler). Petite Chez Scheme was originally freely distributable and is now distributed open-source as part of Chez Scheme.

Performance
In one series of benchmarks, Chez Scheme was among the fastest available Scheme implementations on the Sun SPARC processor architecture, while Petite Chez Scheme was among the slowest implementations on the more common x86 (Pentium 32-bit) processor architecture.

Libraries
Chez Scheme has a windowing system and computer graphics package called the Scheme Widget Library, and is supported by the portable SLIB library..  However the widget library is no longer maintained.

References

External links

The Development of Chez Scheme by R. Kent Dybvig

Chez Scheme formal project page on GitHub

Chez Scheme on the Scheme wiki

Formerly proprietary software
Scheme (programming language) compilers
Scheme (programming language) interpreters
Scheme (programming language) implementations
Software using the Apache license
R6RS Scheme
International Textbook Company. The International Textbook Company (I.T.C.) was founded in 1895 by publisher Thomas J. Foster in Scranton, Pennsylvania.  I.T.C. published instructional papers, booklets, and textbooks for the International Correspondence Schools, a subsidiary department. The textbook company and the school were dependent on each other since their founding.

The International Correspondence School started in 1891 as a question-answer column in the pages of the mining journal Colliery Engineer and Metal Miner, also published by Foster. This column was a response to the in-depth tests required of miners and inspectors by the Pennsylvania Mine Safety Act of 1885.

The I.T.C. merged the Colliery Engineer School of Mines, School of Mines, Correspondence Schools, and the International Correspondence School as the International Correspondence Schools of Scranton, Pennsylvania, under the new International Textbook Company.

Several Scranton correspondence schools had textbooks printed or published by I.T.C. as direct subsidiaries of the school, including the Institute of Business Science and the Woman's Institute of Domestic Arts & Sciences.

Foster's unethical business practices bankrupted the school and the book company. Philanthropic Scranton bankers and businessmen who saw the potential impact this school would have on their workforce and community reorganized it under receivership in 1905.   Many men and women who didn't have the means for schooling past grade 8 in the first half of the 20th century can thank them for their vision.  I.C.S. and other later schools such as The American School of Correspondence in Chicago, Illinois, provided a way to gain practical knowledge that could better their earning potential without quitting work for 3–4 years.

The International Library of Technology was published by I.T.C. These books were bound volumes of the course materials for the more than 240 courses offered.  These books were used and made available in at least 184 colleges, including the U.S. Military Academy at West Point and Cornell University, and at least 649 public libraries.

Related
The International Correspondence Schools of Scranton, Pennsylvania, was a pioneer in post-secondary distance education.  It was operated under that name from 1895 until bankruptcy in 1996. I.C.S. is in operation today as the Penn Foster Career School. The American School of Correspondence in Chicago, Illinois, is still in operation as a private secondary school.

References 

Publishing companies established in 1895
Book publishing companies based in Pennsylvania
1895 establishments in Pennsylvania
Optical beam-induced current. Optical beam induced current (OBIC) is a semiconductor analysis technique performed using laser signal injection. The technique 
uses a scanning laser beam to create electron–hole pairs in a semiconductor sample. This induces a current which may be analyzed to determine the sample's properties, especially defects or anomalies.

Conventional OBIC scans an ultrafast laser beam over the surface of the sample, exciting some electrons into the conduction band through what is known as 'single-photon absorption'. As its name implies, single-photon absorption involves just a single photon to excite the electron into conduction. This can only occur if that single photon carries enough energy to overcome the band gap of the semiconductor (1.12 eV for Si) and provide the electron with enough energy to make it jump into the conduction band.

Uses 

The technique is used in semiconductor failure analysis to locate buried diffusion regions, damaged junctions and gate oxide shorts.

The OBIC technique may be used to detect the point at which a focused ion beam (FIB) milling operation in bulk silicon of an IC must be terminated (also known as endpoint). This is accomplished by using a laser to induce a photocurrent in the silicon while simultaneously monitoring the magnitude of the photocurrent by connecting an ammeter to the device's power and ground. As the bulk silicon is thinned, the photocurrent is increased and reaches a peak as the depletion region of the well to substrate junction is reached. This way, endpoint can be achieved to just below the well depth and the device remains operational.

See also
List of laser articles

Notes

References
.
.

Further reading 
 

Semiconductor analysis
Comparison of spreadsheet software. Spreadsheet is a class of application software design to analyze tabular data called "worksheets". A collection of worksheets is called a "workbook". Online spreadsheets do not depend on a particular operating system but require a standards-compliant web browser instead. One of the incentives for the creation of online spreadsheets was offering worksheet sharing and public sharing or workbooks as part of their features which enables collaboration between multiple users. Some on-line spreadsheets provide remote data update, allowing data values to be extracted from other users' spreadsheets even though they may be inactive at the time.

General

Operating system support
The operating systems the software can run on natively (without emulation).  Android and iOS apps can be optimized for Chromebooks and iPads which run the operating systems ChromeOS and iPadOS respectively, the operating optimizations include things like multitasking capabilities, large and multi-display support, better keyboard and mouse support.

Supported file formats
This table gives a comparison of what file formats each spreadsheet can import and export.  "Yes" means can both import and export.

Rows and Columns 

-* 32-bit addressable memory on Microsoft Windows, i.e. ~2.5 GB.

See also
List of spreadsheet software
Comparison of word processors
Comparison of office suites

Notes

References

Spreadsheets
spreadsheet software
Picolinic acid. Picolinic acid is an organic compound with the formula . It is a derivative of pyridine with a carboxylic acid (COOH) substituent at the 2-position. It is an isomer of nicotinic acid and isonicotinic acid, which have the carboxyl side chain at the 3- and 4-positions, respectively. It is a white solid although impure samples can appear tan. The compound is soluble in water.

Production
On a commercial scale, picolinic acid is produced by ammoxidation of 2-picoline followed by hydrolysis of the resulting nitrile:

It is also produced by oxidation of picoline with nitric acid.  

In the laboratory, picolinic acid is formed from 2-methylpyridine by oxidation with potassium permanganate (KMnO4).

Reactions

Hydrogenation of picolinic acid gives piperidine-2-carboxylic acid, a precursor to the drug Mepivacaine.

Picolinic acid is a bidentate chelating agent of elements such as chromium, zinc, manganese, copper, iron, and molybdenum in the human body.

It is a substrate in the Mitsunobu reaction. In the Hammick reaction, picolinic acid reacts with ketones to give pyridine-2-carbonols:

Biosynthesis
Picolinic acid is a catabolite of the amino acid tryptophan through the kynurenine pathway. Its function is unclear, but it has been implicated in a variety of neuroprotective, immunological, and anti-proliferative effects. In addition, it is suggested to assist in the absorption of zinc(II) ions and other divalent or trivalent ions through the small intestine.

Picolinates 
Salts of picolinic acid (picolinates) include:
 Chromium(III) picolinate
 Zinc picolinate

See also 
 Dipicolinic acid

References 

2-Pyridyl compounds
Glycine receptor agonists
Chelating agents
Aromatic acids
Plasma-powered cannon. A plasma cannon (also called an electrothermal accelerator) is an experimental projectile weapon, which accelerates a projectile by means of a plasma discharge between electrodes at the rear of the barrel, generating a rapid increase in pressure. It functions similarly to other types of firearms, except that it uses a plasma discharge instead of a chemical propellant (e.g. black powder or nitrocellulose).

Design

To generate the energy required to make a plasma discharge,  a high current, high voltage source, and a large capacitor bank are used. Both are attached in series to the electrode system in the cannon's barrel. The capacitor is loaded with as high a voltage as possible. However, militarily useful energy is achieved with as little as several kilojoules. The capacitor is then discharged. The  gap between the electrodes ionizes, turning the non-flammable propellant medium  into a super heated conductive plasma. Associated volumetric expansion propels the projectile from the barrel at high velocity.

Advantages and disadvantages
The advantage of a plasma cannon is that it uses electricity as its energy source. The more energy that is supplied the faster the gases expand and the faster the projectile can be accelerated. This makes it possible to "dial-in" any velocity desired and allows the projectile to reach a speed at which it would be possible to "outrun" the burn rate of a conventional propellant.

A clear disadvantage of the plasma cannon is its weight. Even a small plasma cannon with only the firepower of an air gun weighs about  (without current supply). A foot soldier thus could not carry a plasma cannon powerful enough to be useful. It would have to be mounted in a stationary position or on a vehicle. It would be impossible for a soldier to carry a plasma cannon with the firepower of an actual cannon.

See also
 Electrothermal-chemical technology
 Plasma railgun

Further reading
Günter Wahl: Blitz und Donner selbst erzeugt (in German)

Artillery
Plasma technology and applications
Recovery testing. In software testing, recovery testing is the activity of testing how well an application is able to recover from crashes, hardware failures and other similar problems.

Recovery testing is the forced failure of the software in a variety of ways to verify that recovery is
properly performed. Recovery testing should not be confused with reliability testing, which tries to discover the specific point at which failure occurs. Recovery testing is basically done in order to check how fast and better the application can recover against any type of crash or hardware failure etc. Recovery testing is simulating failure modes or actually causing failures in a controlled environment. Following a failure, the failover mechanism is tested to ensure that data is not lost or corrupted and that any agreed service levels are maintained (e.g., function availability or response times). Type or extent of recovery is specified in the requirement specifications. It is basically testing how well a system recovers from crashes, hardware failures, or other catastrophic problems

Examples of recovery testing:
 While an application is running, suddenly restart the computer, and afterwards check the validness of the application's data integrity.
 While an application is receiving data from a network, unplug the connecting cable. After some time, plug the cable back in and analyze the application's ability to continue receiving data from the point at which the network connection disappeared.

See also
 Fault injection
 Failsafe

References

Software testing