omniomni/omni-engineering huggingface dataset:
Enthalpy of sublimation. In thermodynamics, the enthalpy of sublimation, or heat of sublimation, is the heat required to sublimate (change from solid to gas) one mole of a substance at a given combination of temperature and pressure, usually standard temperature and pressure (STP). It is equal to the cohesive energy of the solid. For elemental metals, it is also equal to the standard enthalpy of formation of the gaseous metal atoms. The heat of sublimation is usually expressed in kJ/mol, although the less customary kJ/kg is also encountered.

Sublimation enthalpies

See also
 Heat
 Sublimation (chemistry) 
 Phase transition
 Clausius-Clapeyron equation

References 

Enthalpy
Haynes–Shockley experiment. In semiconductor physics, the Haynes–Shockley experiment was an experiment that demonstrated that diffusion of minority carriers in a semiconductor could result in a current.  The experiment was reported in a short paper by Haynes and Shockley in 1948, with a more detailed version published by Shockley, Pearson, and Haynes in 1949.  
The experiment can be used to measure carrier mobility, carrier lifetime, and diffusion coefficient.

In the experiment, a piece of semiconductor gets a pulse of holes, for example, as induced by voltage or a short laser pulse.

Equations

To see the effect, we consider a n-type semiconductor with the length d. We are interested in determining the mobility of the carriers, diffusion constant and relaxation time. In the following, we reduce the problem to one dimension.

The equations for electron and hole currents are:

where the js are the current densities of electrons (e) and holes (p), the μs the charge carrier mobilities, E is the electric field, n and p the number densities of charge carriers, the Ds are diffusion coefficients, and x is position. The first term of the equations is the drift current, and the second term is the diffusion current.

Derivation

We consider the continuity equation:

Subscript 0s indicate equilibrium concentrations.  The electrons and the holes recombine with the carrier lifetime τ.

We define 
 

so the upper equations can be rewritten as:

In a simple approximation, we can consider the electric field to be constant between the left and right electrodes and neglect ∂E/∂x. However, as electrons and holes diffuse at different speeds, the material has a local electric charge, inducing an inhomogeneous electric field which can be calculated with Gauss's law:

where ε is permittivity, ε0 the permittivity of free space, ρ is charge density, and e0 elementary charge.

Next, change variables by the substitutions: 

and suppose δ to be much smaller than . The two initial equations write:

Using the Einstein relation , where β is the inverse of the product of temperature and the Boltzmann constant, these two equations can be combined:

where for D*, μ* and τ* holds:
,  and 

Considering n >> p or p → 0 (that is a fair approximation for a semiconductor with only few holes injected), we see that D* → Dp, μ* → μp and 1/τ* → 1/τp. The semiconductor behaves as if there were only holes traveling in it.

The final equation for the carriers is:

This can be interpreted as a Dirac delta function that is created immediately after the pulse. Holes then start to travel towards the electrode where we detect them. The signal then is Gaussian curve shaped.

Parameters μ, D and τ can be obtained from the shape of the signal.

where d is the distance drifted in time t0, and δt the pulse width.

See also

Alternating current
Conduction band
Convection–diffusion equation
Direct current
Drift current
Free electron model
Random walk

References

External links
  Applet simulating the Haynes–Shockley experiment 
 Video explaining the original experiment
 Educational approach to the HS experiment

Semiconductors
Charge carriers
Selective non-catalytic reduction. Selective non-catalytic reduction (SNCR) is a method to lessen nitrogen oxide emissions in conventional power plants that burn biomass, waste and coal. The process involves injecting either ammonia or urea into the firebox of the boiler at a location where the flue gas is between  to react with the nitrogen oxides formed in the combustion process. The resulting product of the chemical redox reaction is molecular nitrogen (N2), carbon dioxide (CO2), and water (H2O).

The conversion of noxious NOx to innocuous N2 is described by the following simplified equation:
4 NO + 4 NH3 + O2 → 4 N2 + 6 H2O

When urea is used, the pre-reaction occurs to first convert it to ammonia:
NH2CONH2 + H2O → 2 NH3 + CO2
Being a solid, urea is easier to handle and store than the more dangerous ammonia (NH3), so it is the reactant of choice.

The reaction requires a sufficient reaction time within a certain temperature range, typically , to be effective.  At lower temperatures the NO and the ammonia do not react. Ammonia that has not reacted is called ammonia slip and is undesirable, as the ammonia can react with other combustion species, such as sulfur trioxide (SO3), to form ammonium salts.

At temperatures above 1093 °C ammonia oxidizes:
4 NH3 + 5 O2 -> 4 NO + 6 H2O
In that case NO is produced instead of being removed. 

A further complication is mixing. In general, more NO will form in the center of the reaction vessel and less near the walls, as the walls are cooler than the center. Thus, more ammonia must find its way to the center and less near the walls, otherwise NO in the center meets insufficient ammonia for reduction and excess ammonia near the walls slips through.

Although in theory selective non-catalytic reduction can achieve the same efficiency of about 90% as selective catalytic reduction (SCR), the practical constraints of temperature, time, and mixing often lead to worse results in practice. However, selective non-catalytic reduction has an economical advantage over selective catalytic reduction, as the cost of the catalyst is not there.

References

External links
How SNCR Works

See also
Selective catalytic reduction

NOx control
High Performance Knowledge Bases. The High Performance Knowledge Bases (HPKB) was a DARPA research program to advance the technology of how computers acquire, represent and manipulate knowledge.  The successor of the HPKB project was the Rapid Knowledge Formation (RKF) project.

The primary results of the HPKB project was to focus further research on the Knowledge acquisition bottleneck problem.

HPKB was divided programmatically into three groups:

 Integrators
 Technology developers
 Challenge problem developers

See also 
 Knowledge base
 Cyc - commercial knowledge base
 OpenCyc - Open source version of Cyc
 Electronic Directory Research (EDR) - Japanese large knowledge base effort
 Project Halo - Ultimate successor project
 Rapid Knowledge Formation (RKF)- follow-on project
 SUMO - Suggested Upper Merged Ontology
 Wikipedia - example of large knowledge base that is not yet semantically parsable
 WordNet - a semantic network of words, terms used in the English language

External links 
  DARPA HPKB Home Page
 Cohen, P., Schrag, R., Jones, E., Pease, A., Lin, A., Starr, B., Gunning, D. and Burke, M. DARPA High-Performance Knowledge Bases Project AI Magazine Volume 19 Number 4 (1998)

References 
Web Intelligence: First Asia-Pacific Conference, Wi 2001, Maebashi City, Japan, October 23–26, by N Zhong, Y Yao, J Liu

DARPA
Alex Smith (engineer). Sir Alex Smith (15 October 1922 – 28 February 2003) was a Scottish industrial scientist and educator. Born in Lossiemouth, Moray, he was educated at Lossiemouth, Elgin Academy and, following the winning of a scholarship, Aberdeen University.

The Second World War interrupted his university years, but he returned to Aberdeen after serving the war years in the Royal Navy. After graduation, he went to work for Rolls-Royce, where he worked his way up to Head of Advanced Research and played a major part in the development of the RB211 aircraft engine.

On leaving Rolls-Royce, Smith took up the challenge of creating Manchester Polytechnic, which eventually become Manchester's largest university, Manchester Metropolitan. He was immensely proud of his achievements as Polytechnic's first director.

He died in Alderley Edge, Cheshire, England at the age of 80. His autobiography Lock up The Swings on Sundays was published by The Memoir Club.

External links
Obituary in the Times Online

1922 births
2003 deaths
Royal Navy sailors
People from Lossiemouth
Alumni of the University of Aberdeen
People associated with Manchester Metropolitan University
Scottish aerospace engineers
20th-century Scottish businesspeople
Scottish physicists
Scottish scholars and academics
Royal Navy personnel of World War II
20th-century Scottish engineers
Military personnel from Moray
Cosmobot. CosmoBot is a prototype telerehabilitation robot designed to treat children with disabilities such as Autism Spectrum disorders, Down Syndrome, cerebral palsy, muscular dystrophy, apraxia, neurodevelopmental disorders, and language developmental disorders.

See also
 Autism therapies
 Autism friendly
 Educational Psychology
 Physical Therapy
 Telerobotics
 Voice command device

References

 Brisben, A. J., Lockerd, A. D., & Lathan, C. (Jun, 2004). Design evolution of an interactive robot for therapy. Telemedicine Journal and e-Health. 10, 252–259.
 Lathan, C., Brisben, A., & Safos, C. (April 2005). CosmoBot levels the playing field for disabled children. Interactions -- Special Issue: Robots!. 12, 14–16.
 Lathan, C.E., Tracey, M. R., Vice, J.M., Druin, A., & Plaisant, C. Robotic Apparatus and Wireless Communication System, US Patent Application 10/085, 821 filed February 27, 2002

External links
 AT Kid Systems
 RERC on Telerehabilitation 

Telerehabilitation
Therapeutic robots
1999 robots
Robots of the United States
Humanoid robots
Rolling robots
Monowave. The MonoWave is a monophonic 2U 19" rack synthesizer by Modulus Electronics, UK.

History 
This synth was first shown in 2001 by its inventor Paula Maddox on a PPG user/fan meeting. Because its attraction to some synthesizer players at the event, the project was started with 5 beta-test units to test the software and hardware. By spring 2002. the serial production of a 25-piece limited run started. About a year later, all units were sold.

Late in 2005, after many attempts at designing new products, Paula decided to close Modulus Electronics and its website (modulus-music.com). In order that people could still enjoy the Monowave, she worked with Elby Designs to create a kit version of the monowave offering the same features. The software was released at the same time under the GPL license, in the hope that others would continue to develop its features.

Features 

It features two digital oscillators with 256 different single-cycle waveshapes selectable individually. There is also a unique de-res, a function to lower the digital waveshapes' sample resolution, to give a sound very much like the famous German PPG wave synthesizers from the eighties. The signal of these oscillators and their suboctave signals are mixed together and then feed in the pure analog part of the synth, a Moog-style 24 dB transistor-ladder lowpass filter  and a VCA. Both of them are controlled by their own ADSR envelope. Depending on the installed operating system version, it may either have an arpeggiator or a MIDI-velocity to wavenumber function.

The MonoWave has no patch memory. It can be played via MIDI by sequencers or MIDI keyboards.

External links
 http://www.modalelectronics.com - Paula Maddox's new company Modal Electronics.
 http://www.till-kopper.de/monowave.html  - bi-language page by a MonoWave user, manuals author and beta-tester.
 https://web.archive.org/web/20060825221305/http://www.elby-designs.com/monowave/monowave-about.htm - Monowave kit at Elby Designs.
Synthesizers
Steve Deering. Stephen Deering is a former Fellow at Cisco Systems, where he worked on the development and standardization of architectural enhancements to the Internet Protocol. Prior to joining Cisco in 1996, he spent six years at Xerox's Palo Alto Research Center, engaged in research on advanced Internet technologies, including multicast routing, mobile internetworking, scalable addressing, and support for multimedia applications over the Internet. He is a former member of the Internet Architecture Board, a past chair of numerous Working Groups of the Internet Engineering Task Force (IETF), the inventor of IP multicast, and the lead designer of the new version of the Internet Protocol, IPv6.  By 2017 he was retired and living in Vancouver, British Columbia.

Education
Deering received his B.Sc. (1973) and M.Sc. (1982) from the University of British Columbia, and his Ph.D. (1991) from Stanford University. He attended high school at Shawnigan Lake School on Vancouver Island.

Recognition
Deering is the recipient of the 2010 IEEE Internet Award for his work in IP multicast and IPv6.  He was declared the 1994 "Geek of the Year" by Internet Talk Radio.

External links

References

Living people
Canadian computer scientists
Computer systems researchers
Stanford University alumni
Cisco people
Scientists at PARC (company)
Year of birth missing (living people)
Shawnigan Lake School alumni
University of British Columbia alumni
Edwin Hill. Edwin Hill may refer to:

 Edwin Hill (engineer) (1793–1876), British inventor (of envelope manufacturing machine), Controller of Stamps
 Edwin Hill-Trevor, 1st Baron Trevor (1819–1894), styled as Lord Edwin Hill until 1862
 Edwin A. Hill (active 1900), American inventor of the Hill system for writing chemical formulae
 Edwin J. Hill (1894–1941), U.S. Navy sailor posthumously awarded the Medal of Honor
 Edwin D. Hill (1937–2018), American president of the International Brotherhood of Electrical Workers
 Edwin Escobar Hill (born 1969), Guatemalan politician

See also 
 Ed Hill (disambiguation)
 Edwin St Hill (1904–1957), Trinidadian cricketer
 Hill (surname)
Common Data Representation. Common Data Representation (CDR) is used to represent structured or primitive data types passed as arguments or results during remote invocations on Common Object Request Broker Architecture (CORBA) distributed objects.

It enables clients and servers written in different programming languages to work together. For example, it translates little-endian to big-endian. It assumes prior agreement on type, so no information is given with data representation in messages.

External links
 Official CDR spec (see PDF page 4).
 ACE Library provides CDR streams.

Common Object Request Broker Architecture
Data serialization formats
CRANN. CRANN, the Centre for Research on Adaptive Nanostructures and Nanodevices, is Ireland's first purpose-built research institute whose purpose is to perform nanoscience research. It is housed in the Naughton Institute on the campus of Trinity College Dublin.  is the Irish word for tree.

The three major research areas are Nano-Biology of Cell Surface Interactions, Bottom-Up Fabrication and Testing of Nanoscale Integrated Devices, and Magnetic Nano-Structures and Devices.

As of 2018, CRANN was led by its director, Prof. Stefano Sanvito, along with deputy director Prof. John Donegan, and executive director Dr. Lorraine Byrne. Previously, the management team consisted of Prof. John Boland (director), Prof. Mike Coey (deputy director), Dr. Jussi Tuovinen (executive director).

The research teams are led by principal investigators from Trinity College including John Pethica, who is the director of the Naughton Institute.

References

External links
 CRANN on TCD website

Trinity College Dublin
International Centre for Genetic Engineering and Biotechnology. The International Centre for Genetic Engineering and Biotechnology (ICGEB) was established as a project of the United Nations Industrial Development Organization (UNIDO) in 1983. The Organisation has three Component laboratories with over 45 ongoing research projects in Infectious and Non-communicable diseases, Medical, Industrial and Plant Biology Biotechnology in: Trieste, Italy, New Delhi, India and Cape Town, South Africa.

On February 3, 1994, under the direction of Arturo Falaschi the ICGEB became an autonomous International Organisation and now has over 65 Member States across world regions.

Its main pillars of action comprise: Research, Advanced Education through PhD and Postdoctoral Fellowships, International Scientific Meetings and Courses, competitive Grants for scientists in Member States and Technology Transfer to industry.

References

External links
ICGEB official Website

Genetic engineering
Intergovernmental organizations established by treaty
Organizations established in 1994
Scientific organisations based in Italy
Trieste
United Nations Industrial Development Organization
Italy and the United Nations
India and the United Nations
South Africa and the United Nations
Engineering & Technology. Engineering & Technology (E+T) is a science, engineering and technology magazine published by Redactive on behalf of IET Services, a wholly owned subsidiary of the Institution of Engineering and Technology (IET), a registered charity in the United Kingdom. The magazine is issued 6 times per year in print and online. The E+T website is also updated regularly with news stories. E+T is distributed to the 154,000 plus membership of the IET around the world.

The magazine was launched in April 2008 as a result of the merger between the Institution of Electrical Engineers and the Institution of Incorporated Engineers on 31 March 2006. Prior to the merger, both organisations had their own membership magazine, the IEE's monthly IEE Review and the IIE's Engineering Technology. Engineering & Technology is an amalgamation of the two, and was initially published monthly. Alongside this, members also received one of seven other monthly magazines published by the IET relating to a field of the subject of their choice, with the option to purchase any of the other titles. In January 2008, the IET merged these seven titles into E+T to make a nearly fortnightly magazine with a larger pagination, providing all members with one magazine covering all topics.  In January 2011 the frequency was reduced to 12 times per year and to 11 times per year in 2015 and 10 times per year in 2017.

E+T journalists have been shortlisted and won multiple magazine industry awards, including those presented by the British Society of Magazine Editors, Trade And Business Publications International and the Professional Publishers Association.

References

External links
 Official website

Professional and trade magazines
Engineering magazines
Science and technology magazines published in the United Kingdom
2008 establishments in the United Kingdom
Magazines established in 2008
Institution of Engineering and Technology
Linear dynamical system. Linear dynamical systems are dynamical systems whose evolution functions are linear.  While dynamical systems, in general, do not have closed-form solutions, linear dynamical systems can be solved exactly, and they have a rich set of mathematical properties.  Linear systems can also be used to understand the qualitative behavior of general dynamical systems, by calculating the equilibrium points of the system and approximating it as a linear system around each such point.

Introduction

In a linear dynamical system, the variation of a state vector 
(an -dimensional vector denoted ) equals a constant matrix
(denoted ) multiplied by 
.  This variation can take two forms: either 
as a flow, in which  varies 
continuously with time

or as a mapping, in which 
 varies in discrete steps

These equations are linear in the following sense: if 
 and  
are two valid solutions, then so is any linear combination 
of the two solutions, e.g., 
 
where  and 
are any two scalars.  The matrix  
need not be symmetric.

Linear dynamical systems can be solved exactly, in contrast to most nonlinear ones.  Occasionally, a nonlinear system can be  solved exactly by a change of variables to a linear system.  Moreover, the solutions of (almost) any nonlinear system can be well-approximated by an equivalent linear system near its fixed points.  Hence, understanding linear systems and their solutions is a crucial first step to understanding the more complex nonlinear systems.

Solution of linear dynamical systems

If the initial vector 
is aligned with a right eigenvector  of 
the matrix , the dynamics are simple

where  is the corresponding eigenvalue;
the solution of this equation is 

as may be confirmed by substitution.

If  is diagonalizable, then any vector in an -dimensional space can be represented by a linear combination of the right  and left eigenvectors (denoted ) of the matrix .

Therefore, the general solution for  is 
a linear combination of the individual solutions for the right
eigenvectors

Similar considerations apply to the discrete mappings.

Classification in two dimensions 

The roots of the characteristic polynomial det(A - λI) are the eigenvalues of A.  The sign and relation of these roots, , to each other may be used to determine the stability of the dynamical system 

For a 2-dimensional system, the characteristic polynomial is of the form  where  is the trace and  is the determinant of A.  Thus the two roots are in the form:

,
and  and .  Thus if  then the eigenvalues are of opposite sign, and the fixed point is a saddle.  If  then the eigenvalues are of the same sign.  Therefore, if  both are positive and the point is unstable, and if  then both are negative and the point is stable.  The discriminant will tell you if the point is nodal or spiral (i.e. if the eigenvalues are real or complex).

See also

 Linear system
 Dynamical system
 List of dynamical system topics
 Matrix differential equation

Dynamical systems
John Inshaw. John Inshaw (1807–1893) was a mechanic and inventor who lived in Aston, now a district of Birmingham, England. Inshaw designed and built machinery for the railway and shipping industries and constructed a steam carriage. He was consulted by George Stephenson on the design of wheels for steam locomotives. From 1859 to 1886, Inshaw operated the Steam Clock Tavern on Morville Street in which he exhibited working models and examples of his mechanical devices. It was named after the most notable, although perhaps least practical, of his inventions.

Inshaw Steam Carriage
John Inshaw built a steam carriage in 1881. It had a water-tube boiler, working at 200 psi, and steam could be raised in 20 minutes. The engine had two cylinders of 4in bore by 8in stroke, three gears and double-gear drive to the rear wheels. When loaded with ten passengers it weighed 35 cwt and averaged 8–12 mph.

Inshaw wrote about his machine in The Engineer magazine, published 1 November 1895. He claimed that he discontinued his experiments because of the law prohibiting the use of steam-propelled carriages and that he hoped to build a second one as soon as the law was repealed. A photograph of the carriage was printed in an American book, in 1904: "English & American Steam Carriages and Traction Engines". The author, William Fletcher, noted that the Inshaw Steam Carriage "was well known in Birmingham and district".

See also
 Steam clock

References

External links
January 1856 edition of the journal The Engineer featuring a description and illustration of Inshaw's Regent's Canal Tug-Boat – (online access requires subscription) 
John Inchaw's Steam Clock
The Steam Narrow Boat – including a description of Inshaw's notable twin-screw propeller-driven steam boats

1807 births
1893 deaths
English inventors
Steam road vehicles
People from Birmingham, West Midlands