omniomni/omni-engineering huggingface dataset:
NeXTcube Turbo. The NeXTcube Turbo is a high-end workstation computer developed, manufactured and sold by NeXT. It superseded the earlier NeXTcube workstation and is housed in the same cube-shaped magnesium enclosure. It runs the NeXTSTEP operating system.

Hardware 

The NeXTcube Turbo is a development of the earlier NeXTcube. It differs from its predecessor in having a 33 MHz 68040 processor.

The NeXTdimension board can also be used in the NeXTcube Turbo.

There was also a very rare accelerator board known as the Nitro; between 5 and 20 are estimated to have been made. It increased the speed of a NeXTcube Turbo by replacing the standard 33 MHz processor with a 40 MHz one.

Specifications

 Display: 1120×832 17" grayscale MegaPixel Display
 Operating system: NeXTSTEP, OPENSTEP
 CPU: 33 MHz 68040 with integrated floating-point unit
 Digital signal processor: 25 MHz Motorola DSP56001
 RAM: 16 MB, expandable to 128 MB (Four 72-pin SIMM slots)
 Floppy Drive: 2.88 MB (optional)
 Hard Drive: 400 MB, 1.4 GB or 2.8 GB SCSI drive
 Expansion: four NeXTbus slots (mainboard uses one slot)
 Size (H × W × D): 12" × 12" × 12"

See also 
 NeXT Computer
 NeXTstation
 NeXT character set
 Power Mac G4 Cube

References

External links 
 old-computers.com — NeXTcube
 NeXTComputers.org

Computer workstations
NeXT
History of the Internet
Steve Jobs
68k-based computers
Hemilability. In coordination chemistry and catalysis hemilability (hemi - half, lability - a susceptibility to change) refers to a property of many  polydentate ligands which contain at least two electronically different coordinating groups, such as hard and soft donors. These  hybrid or heteroditopic ligands form complexes where one coordinating group is easily displaced from the metal centre while the other group remains firmly bound; a behaviour which has been found to increase the reactivity of  catalysts when compared to the use of more traditional ligands.

Overview 
In general, catalytic cycles can be divided into 3 stages:

 Coordination of the starting material(s)
 Catalytic transformation of the starting material(s) to the product(s)
 Displacement of the product(s) to regain the catalyst (or pre-catalyst)  

Traditionally the focus of catalytic research has been on the reaction taking place in the second stage, however there will be energy changes associated with the beginning and end steps due to their effect on the coordination sphere and geometry of the complex, as well as its oxidation number in cases of oxidative addition and reductive elimination. When these energy changes are large they can dictate the turn-over rate of the catalyst and hence its effectiveness.

Hemilabile ligands reduce the activation energy of these changes by readily undergoing partial and reversible displacement from the metal centre. Hence a co-ordinately saturated hemilabile complex will readily reorganise to allow the coordination of reagents but will also promote the ejection of products due to re-coordination of the labile section of the ligand. The low energy barrier between the fully and hemi coordinated states results in frequent inverconvertion between the two, which promotes a fast catalytic turn-over rate.

Hemilabile ligands dissociate in one of three main ways; an "on/off" mechanism where they are constantly dissociating and re-associating, a displacement mechanism where they dissociate easily when exposed to a competing substrate, or redox switching where the oxidation state of the ligand is used to tune its affinity for the metal center.

Examples 
 The oxidative addition of MeI to Ir(I) complexes was shown to proceed about 100 times faster with a hemilabile phosphane ligand compared to a very similar non-labile ligand.
 Hydrovinylation (olefin dimerisation), which is typically difficult to carry out enantioselectively, has been shown to proceed with high enantiomeric excess when using a chiral phosphine ligand with an appropriately placed hemilabile coordinating group. (review article) The Pauson–Khand reaction, which is conceptually similar, has also been shown to give improved results when hemilabile P,S type hybrid ligands were used.
 Iridium(I) complexes incorporating hemilabile ligands which contain methoxy, dimethylamino, and pyridine as donor functions have been shown to be effective catalysts for transfer hydrogenation.

See also 
 Scorpionate ligand
 Pincer ligand
 Weak-Link Approach (supramolecular chemistry)
 2-(Diphenylphosphino)anisole

References

Catalysis
Coordination chemistry
Indium wire. Indium is a soft, malleable, silver, shiny metal with atomic weight of 114.818 and resides as number 49 on the Chemical Periodic Table. Indium is a superconductor below 3.4 K, has a resistance of 8.8 micro-ohms at 20 C, a melting point of 156.598 C, a boiling point of 2027 Cº, and a density of 7.31 g/cc. Indium can be alloyed with a wide range of other metals to lower their melting point.

Indium is an ideal thermal interface material for heat dissipation in many of today's very hot integrated circuits. Of all the common materials, copper and aluminum have the highest thermal conductivity. But on the micro level most materials are very rough and a two piece sandwich of copper may not have a good conductive path between them. To overcome this limitation, indium is the ideal material due to its high bulk thermal conductivity (82W/mK) and its soft compressibility allowing it to fill voids in rough surfaces. In addition, as a seal indium will not pump out or dry out. In fact, indium has the unique ability to cold weld two dissimilar materials if the materials have a thin coating of .002”-.003” of indium they will ‘cold-weld’ together if the clamping pressure is more than 40 psi.

When indium is compressed its bulk thermal conductivity of 82 W/mK pushes down the resistance at the interface to be much lower than greases, fluids, or adhesives. For high power applications there is no better thermal interface material than indium due to its high conductivity, low tensile strength, and ability to alter melting point of alloys, in addition to indium's ability to dissipate great amounts of heat away from sensitive devices.

Applications 

 Vacuum seals
 Cryostats
 Dilution Refrigerators
 Optical Windows
 Lasers
 Cryocoolers
 Cold Heads
 Thermal links

Technical Information 

 Groove Design
 
 PRODUCTION RATE FOR (5 OZ.) 140 GRAM INGOT
 
 SIZE		LGTH		FT./OZ.	GR./FT.	AREA		GROOVE 'D'
  'W'								(sq. in.)	80% 90%
 .020"(0.5mm)	300'		60' (20'/$100)	 .46		.000314	
 .030"		135'		27'		1.04		.000706	.020" .021"
 .040" (1.0mm)	75'		15'		1.88		.001256	.025" .028"
 .050"		50'		10'		2.80	 .001962	.031" .035"
 .060"(1.5mm)	35'		7'		4.00	 .002826	.038" .042"
 .0625"		32'		6.4'		4.37
 .070"		26'		5.2'		5.38		.003846	.044" .049"	
 .080"(2.0mm)	20'		4'		7.00	 .005024	.050" .056"
 .090"		15'		3'		9.33	 .006358	.056" .064"
 .100"		12.5'		2.5'		11.2		.007850	.063" .070"
 .125"		8'		1.6'		17.50 .012265	.078" .088"	
 .1875"		44"		8.76"	 38.35 .027597	
 					 D=Half dia. +.005>.015 min.
 Rectangular groove dimensions: [Depth x Width = .80min. x cross section]

References 

Indium
ScREC. ScREC is a supercomputer developed by the Research Centre for Modeling and Simulation (RCMS) at the National University of Sciences and Technology, Pakistan (NUST) in Islamabad, Pakistan. With a 132 teraflops performance, it is currently the fastest supercomputer in Pakistan.

System specifications
ScREC is able to perform parallel computing and has a performance speed of 132 teraFLOPS (trillion operations per second). It is the fastest running graphics processing unit (GPU) parallel computing system to have been developed in Pakistan. The supercomputer has multi-core processors and graphics co-processors, with an inter-process communication speed of 40 gigabits per second. According to system specifications, the computer cluster consists of 66 nodes equipped with 30,992 processor cores. Additional component details include:
 32 dual quad core computer nodes (256 processor cores)
 32 Nvidia graphics processing units
 QDR InfiniBand interconnection
 21.6 TB storage

See also
 Information technology in Pakistan
 Supercomputing in Pakistan

References

External links
 Supercomputing Research and Education Facility, Research Centre for Modeling and Simulation (NUST)

Science and technology in Pakistan
Information technology in Pakistan
Parallel computing
GPGPU supercomputers
Supercomputing in Pakistan
Master of Business Engineering. A Master of Business Engineering (MBE) also Master of Engineering Management (MEM) is a two-year master's degree. The program combines management science, business administration, law and economics, technology, and engineering. The content of this academic degree is comparable with those of a Master of Business Administration (MBA) with additional engineering and technology content. The standard period of study is 24 months. According to the European Credit Transfer System (ECTS), one hundred twenty credit points are awarded for the degree. It is required to hold a bachelor's degree in business administration or engineering to get admission to this Master's program.  The Master of Business Engineering (MBE) is an emerging degree. The primary objective of the Master's degree program in Management Engineering is to cultivate individuals who possess not only the technical proficiency to apply engineering principles and methodologies, but also possess the aptitude to effectively manage, coordinate, and guide individuals, projects, departments, and enterprises. The course emphasizes the development of effective decision-making abilities in situations characterized by uncertainty. MBE provides students with the opportunity to acquire knowledge and cultivate skills necessary for the design and management of intricate organizations. This includes aspects such as personnel management, marketing, financial management, production, logistics, project management, and resource allocation. The course aims to equip students with the necessary tools to efficiently address and resolve organizational challenges.The demand for MBE graduates is projected to expand as employers increasingly seek professionals with integrated business and engineering acumen. MBE holders may pursue careers across industries like manufacturing, logistics, energy, healthcare, or consulting. With experience, MBE graduates may ascend and attain top leadership positions within their respective industries, overseeing teams of engineers, managers, and other professionals. Their cross-functional skillset allows them to effectively communicate complex technical concepts to business stakeholders.The MBE degree is as rigorous as an MBA program, if not more so, and typically requires two years of full-time study to complete. It equips professionals with the skills to lead complex engineering projects and excel in management positions.

References

Business Engineering, Master
Business qualifications
Management education
Splint (laboratory equipment). A splint (or spill or splinter) is a simple piece of equipment used in scientific laboratories. Splints are typically long, thin strips of wood, about 6 inches (15 cm) long and ¼ inch (6 mm) wide, and are consumable but inexpensive. They are typically used for tasks such as lighting bunsen burners, as the length of the splint allows a flame to be lit without risk to the user's hand, should the burner flare back. Another use for splints are chemical identification of various gases, and splints are also used to teach simple chemical principles in schools and homes.

Use in chemical identification 

Some gases are hard to distinguish by sight or smell alone. For example, hydrogen, oxygen and nitrogen are all colourless and odourless. Several laboratory experiments are capable of producing relatively pure gas as an end product, and it may be useful to demonstrate the chemical identity of that gas. Burning splints or glowing splints can be used to identify whether a gas is flammable, whether it is oxidising, or whether it is chemically inert.

These tests are not safe for completely unidentified gases, as the energy of their explosion could be beyond the safe confinement of a fragile glass tube. This means that they are really only useful as a demonstration of a gas that is already strongly suspected, and so is known to be safe. In a high school chemistry class, a typical use would be to show the presence of hydrogen (after electrolysis of water, or by reacting a metal with an acid).

Burning (or lighted) splint test 

A splint is lit and held near the opening of the tube, then the stopper is removed to expose the splint to the gas.

If the gas is flammable, the mixture ignites. This test is most commonly used to identify hydrogen, which results with a distinctive 'squeaky pop' sound. Hydrogen is easily ignited and used to definitively conclude what the gas actually is. Further analytical chemistry techniques can clarify the identity of the gas in question.

Glowing splint test 

The glowing splint test is a test for an oxidising gas, such as oxygen. In this test, a splint is lit, allowed to burn for a few seconds, then blown out by mouth or by shaking. Whilst the ember at the tip is still glowing hot, the splint is introduced to the gas sample that has been trapped in a vessel.

Upon exposure to concentrated oxygen gas, the glowing ember flares, and re-ignites to produce a sustained flame. The more concentrated the oxygen, the faster the wood burns, and the more intense the flame. This test is not specific for oxygen, but will react similarly for any oxidising gas (such as nitrous oxide) that supports the combustion of the splint.

See also 
 Flame test
 Spill vase

References

External links 
 
 
 

Laboratory equipment
Articles containing video clips
Kay Sievers. Kay Sievers is a German computer programmer, best known for developing the udev device manager of Linux, systemd and the Gummiboot EFI bootloader. Kay Sievers made major contributions to Linux's hardware hotplug and device management subsystems.
In 2012, together with Harald Hoyer, Sievers was the main driving force behind Fedora's merging of the /lib, /bin and /sbin file-system trees into /usr, a simplification which other distributions such as Arch Linux have since adopted.

In April 2014, Linus Torvalds banned Sievers from submitting patches to the Linux kernel for failing to deal with bugs that caused systemd to negatively interact with the kernel.

Kay Sievers worked for Red Hat, Inc. until 2019, Sievers previously worked for Novell.

Kay Sievers grew up in East Germany and nowadays resides in Berlin, Germany.

References

Free software programmers
Living people
Linux people
German computer programmers
Year of birth missing (living people)
Red Hat employees
PFUnit. pFUnit is a Fortran programming language framework for unit testing following the xUnit model. Capabilities include parallel execution using MPI and OpenMP. Development began at NASA Goddard Space Flight Center in 2005. The framework makes extensive use of modern standard features of Fortran (2003, 2008), like support for object-oriented programming.  A python-based preprocessor provides directives reminiscent of other xUnit testing frameworks (e.g. @assert), as well as support for parameterized test cases.  pFUnit can be built using either a GNU make or CMake process.

It is published under the NASA Open Source Agreement version 1.3.

See also 
 List of unit testing frameworks
 Fortran

References

External links 
 GitHub project page
 SourceForge project page
 NASA GSFC project page
 NASA Modeling Guru
 pFUnit (Version 1, now superseded by Versions 2 etc.) tutorial at UCAR, T. Clune, NASA/GSFC, 2012 April 31

Unit testing frameworks
Fortran libraries
Cross-sequential study. A cross-sequential design is a research method that combines both a longitudinal design and a cross-sectional design. It aims to correct for some of the problems inherent in the cross-sectional and longitudinal designs.

In a cross-sequential design (also called an "accelerated longitudinal" or "convergence" design), a researcher wants to study development over some large period of time within the lifespan. Rather than studying particular individuals across that whole period of time (e.g. 20–60 years) as in a longitudinal design, or multiple individuals of different ages at one time (e.g. 20, 25, 30, 35, 40, 45, 50, 55, and 60 years) as in a cross-sectional design, the researcher chooses a smaller time window (e.g. 20 years) to study multiple individuals of different starting ages. An example of a cross-sequential design is shown in the table below.

In this table, over a span of 10 years, from 2000 to 2010, 7 overlapping cohorts with different starting ages could be studied to provide information on the whole span of development from ages 20 to 60.

This design has been used in studies to investigate career trajectories in academia and other phenomena.

References

Research methods
Le Pont de l'Europe. Le Pont de l'Europe  (English title: The Europe Bridge) is an oil painting by French impressionist Gustave Caillebotte completed in 1876. It is held by the  in Geneva, Switzerland. The finished canvas measures .

Description
The image shows pedestrians in the  in the 8th arrondissement of Paris. The plaza is a large bridge joining six avenues, each named for a European capital, over the railroad yards at Gare Saint-Lazare. The view is from the , looking towards the center of the plaza. One of the bridge's trusses is very prominent, visible in half of the image.

Three people are seen in the foreground: a couple walking toward the observer, and a working-class man peering off the bridge toward the train station. A dog walks away from the observer, and other individuals appear in the mid-background.  The man of the couple is a flâneur, an upper-class street observer. He is strolling with a woman dressed in black. She has often been interpreted to be a prostitute, according to contemporary social norms regarding women in public, especially in the area of the train station. Alternatively, the man has been thought to be Caillebotte himself, and the woman to be Caillebotte's companion, Anne-Marie Hagen. The flâneur is looking past his companion in the direction of the other man. Feminist art historian Norma Broude has suggested that Caillebotte, a lifelong bachelor, is signalling his own homosexuality with this gaze. In this reading, Caillebotte is an upper-class man cruising for a lower-class male prostitute in this unsavory neighborhood of Paris. However, Caillebotte's sexual orientation is not definitively known.

Caillebotte displayed this image at the impressionist exhibition of 1877, alongside his Rue de Paris, temps de pluie and Claude Monet's , which gives an alternate view of the bridge.

Caillebotte, as in many of his works, employs perspective. The vanishing point is located behind the head of the man, which is far to the side of the picture, creating oblique perspective. Caillebotte was influenced by Japanese art, especially the work of Hiroshige, and by photography, then a burgeoning artistic field. In turn, this painted composition may have been an influence in photographer Jeff Wall's work from 1982, Mimic, which features similar exaggerated perspective and class tension between the three similarly situated characters.

Gallery

See also
 List of paintings by Gustave Caillebotte

Notes

References

Paintings by Gustave Caillebotte
1876 paintings
Paintings of Paris
Paintings in Geneva
Dogs in art
Bridges in art
3-Chloropropionitrile. 3-Chloropropionitrile is an organic compound with the formula ClCH2CH2CN.  A colorless liquid, it is prepared by the reaction of hydrogen chloride with acrylonitrile.  It is used commercially as a precursor to the drug famotidine.

It is an alkylating agent, as illustrated by its reaction with imidazoles to give the cyanoethylated imidazolium salts. Similarly, it alkylates thiourea, en route to 3-mercaptopropionitrile.

References

Nitriles
CRS-1. CRS-1 may refer to:

Cisco CRS-1, a family of Cisco's Carrier Routing System
SpaceX CRS-1, flight for SpaceX's uncrewed Dragon cargo spacecraft
Cygnus CRS-1, flight for Orbital Sciences Cygnus cargo spacecraft
Commercial Resupply Services — Phase 1 Missions of NASA

See also
 CRS (disambiguation)
Propyleneimine. Propyleneimine (or propylene imine) is the organic compound with the formula CH3CH(NH)CH2.  It is a secondary amine and the smallest chiral aziridine (ring containing C2N).  It is a flammable colorless liquid.  Its derivatives, copolymers and oligomers, are of commercial interest.

Uses
This chemical is used in the paper, textile, rubber and pharmaceutical industries. Propyleneimine is also used in making paint.

The top global producers of this specialty chemical include DuPont, Mitsubishi Chemical Holdings Corporation, Sigma-Aldrich, Dixie Chemical Company, J and K Scientific, Apollo Scientific, Mitsui Chemicals.

The compound is also of  interest for the synthesis of dendrimers, a process that exploits the tendency of aziridines to undergo ring-opening reactions.

Health Effects
NIOSH considers propyleneimine a potential occupational carcinogen.

According to a report prepared for the United Church of Christ, propyleneimine emissions from the Dixie Chemical Company facility in Bayport, Pasadena, Texas, are one of the top ten toxicity-weighted air pollutions in the United States.

References

Aziridines
Platzer Kiebitz. The Platzer Kiebitz () is a German amateur-built aircraft designed by Michael Platzer and made available in the form of plans for amateur construction.

Design and development
The Kiebitz features a strut-braced biplane configuration, a two-seats-in-tandem open cockpit with a small windshield, fixed conventional landing gear and a single engine in tractor configuration.

The aircraft fuselage is made from welded steel tubing, with its flying surfaces covered in doped aircraft fabric. Its  span wing has an area of  and uses interplane cable bracing. Engines from  can be used. The prototype used a  Nissan 12P automotive engine from a Nissan Micra, but Rotax, Volkswagen air-cooled engines and Sauer powerplants have also been employed.

Operational history
Even though the aircraft can only be constructed from plans, the Kiebitz has proven popular with builders for the European Fédération Aéronautique Internationale microlight class.

Specifications (Kiebitz)

References

External links

Homebuilt aircraft
Biplanes
Single-engined tractor aircraft
German sport aircraft
Platzer Motte. The Platzer Motte () is a German amateur-built aircraft designed by Michael Platzer and made available in the form of plans for amateur construction.

Design and development
The Motte features a strut-braced parasol wing configuration, single-seat open cockpit with a small windshield, fixed conventional landing gear and a single engine in tractor configuration.

The aircraft uses the same wing design as the Platzer Kiebitz biplane. The Motte's fuselage is made from metal tubing, with its flying surfaces covered in doped aircraft fabric. Its  span wing has an area of  supported by V-struts and jury struts. Engines used include the  Nissan 12P automotive engine from a Nissan Micra, as well as the  Rotax 462 powerplant.

Pilot access can be difficult due to the proximity of the wing mounted close above the cockpit. Builders have solved this with a trailing edge wing cut-out.

Operational history
The Motte was Platzer's first design, but his later two-seat Kiebitz biplane has proven much more popular than the Motte with builders.

Specifications (Motte)

References

External links

Homebuilt aircraft
Single-engined tractor aircraft
Parasol-wing aircraft
2000s German aircraft