omniomni/omni-engineering huggingface dataset:
Polyconvex function. In the calculus of variations, the notion of polyconvexity is a generalization of the notion of convexity for functions defined on spaces of matrices. The notion of polyconvexity was introduced by John M. Ball as a sufficient conditions for proving the existence of energy minimizers in nonlinear elasticity theory. It is satisfied by a large class of hyperelastic stored energy densities, such as Mooney-Rivlin and Ogden materials. The notion of polyconvexity is related to the notions of convexity, quasiconvexity and rank-one convexity through the following diagram:

Motivation
Let  be an open bounded domain,  and  denote the Sobolev space of mappings from  to . A typical problem in the calculus of variations is to minimize a functional,  of the form

,

where the energy density function,  satisfies -growth, i.e.,  for some  and . It is well-known from a theorem of Morrey and Acerbi-Fusco that a necessary and sufficient condition for  to weakly lower-semicontinuous on  is that  is quasiconvex for almost every . With coercivity assumptions on  and boundary conditions on , this leads to the existence of minimizers for  on . However, in many applications, the assumption of -growth on the energy density is often too restrictive. In the context of elasticity, this is because the energy is required to grow unboundedly to  as local measures of volume approach zero. This led Ball to define the more restrictive notion of polyconvexity to prove the existence of energy minimizers in nonlinear elasticity.

Definition
A function  is said to be polyconvex if there exists a convex function  such that

 

where  is such that

Here,  stands for the matrix of all  minors of the matrix ,  and

where .

When ,  and when , , where  denotes the cofactor matrix of .

In the above definitions, the range of  can also be extended to .

Properties
 If  takes only finite values, then polyconvexity implies quasiconvexity and thus leads to the weak lower semicontinuity of the corresponding integral functional on a Sobolev space.

 If  or , then polyconvexity reduces to convexity.

 If  is polyconvex, then it is locally Lipschitz.

 Polyconvex functions with subquadratic growth must be convex, i.e., if there exists  and  such that 
 for every , then  is convex.

Examples
 Every convex function is polyconvex.
 For the case , the determinant function is polyconvex, but not convex. In particular, the following type of function that commonly appears in nonlinear elasticity is polyconvex but not convex:

References

Convex analysis
Calculus of variations
Matrices
Types of functions
Bartel BM 6. The Bartel BM 6 was a Polish biplane trainer fighter aircraft of 1930. It did not advance beyond the prototype stage.

Design and development
The aircraft was designed by Ryszard Bartel in the Samolot factory in Poznań, as a trainer-fighter plane. The BM-6 prototype, designated BM 6a, was flown on 8 April 1930 in Poznań. Its advantage was an easy construction and maintenance, according to Bartel's design philosophy. A distinguishing feature of all Bartels was an upper wing of a shorter span, because lower and upper wing halves were interchangeable (i.e. the lower wingspan included the fuselage width). It first introduced a mixed construction to Bartel's designs.

After trials, the prototype was modified in July 1930. The prototype was later redesignated BM 6a/II after it was substantially modified. It offered quite good flight characteristics and was capable of aerobatic flight. It was demonstrated in a fighter-plane competition in Bucharest in 1930, along with the similar PZL P.1.

The second prototype BM 6b, with a Wright Whirlwind 220 hp radial engine, was ordered, but work upon it ceased with closure of the Samolot factory in mid-1930. The PWS works, which inherited many of Samolot's projects, did not continue the project, for it had its own similar design, the PWS-11.

Description
Mixed construction biplane. Steel framed fuselage, rectangular in cross-section, canvas covered (engine and upper sections - aluminum covered). Rectangular two-spar wings with rounded ends, plywood and canvas covered. Upper wing span: 7.36 m, lower wing span: 8.10 m. Lower and upper wing halves were interchangeable. Single pilot, sitting in open cockpit, with a windshield. The V8 engine Hispano-Suiza 8Be was modified to lower power output (from 220 hp to 180 hp). Radiator below the fuselage. Fixed landing gear, with a rear skid. Two-blade wooden propeller of fixed pitch. Fuel tank in fuselage: 168 L capacity.

Operational history
After state trials in 1931, the prototype was used in an advanced training school in Grudziądz, then in an aviation training center in Dęblin.

Operators

Polish Air Force (single prototype)

Specifications (BM 6a)

See also

References

Further reading

External links
Photos and drawings
Ugolok Neba site (in Russian)

BM 6
Single-engined tractor aircraft
Biplanes
1930s Polish military trainer aircraft
Aircraft first flown in 1930
Bensen Aircraft. The Bensen Aircraft Corporation was established by Dr. Igor Bensen at Raleigh-Durham International Airport in North Carolina in 1952 to develop and market a variety of helicopters and autogyros of Bensen's own design.

History
The most successful product was the Bensen B-8 that first flew in 1955 and remained in production until the company closed down in 1987.

Aircraft

See also

 Gyrocopter
 Gyroglider

References

Notes

Bibliography

External links 

Bensen Aircraft Foundation archives

Defunct aircraft manufacturers of the United States
Defunct helicopter manufacturers of the United States
Defunct manufacturing companies based in North Carolina
Manufacturing companies established in 1952
Bottleneck (software). In software engineering, a bottleneck occurs when the capacity of an application or a computer system is limited by a single component, like the neck of a bottle slowing down the overall water flow. The bottleneck has the lowest throughput of all parts of the transaction path. 

System designers try to avoid bottlenecks through direct effort towards locating and tuning existing bottlenecks in a software application. Some examples of engineering bottlenecks that appear include the following: a processor, a communication link, and disk IO. A system or application will hit a bottleneck if the work arrives at a comparatively faster pace relative to other processing components. According to the theory of constraints, improving on the occurrences of hot-spot point of the bottleneck constraint improves the overall processing speed of the software. A thought-provoking stipulation of the theory reveals that improving the efficiency of a particular process stage rather than the constraint can generate even more delay and decrease overall processing capabilities of a software.

It is impossible to remove bottlenecks completely since there is always a component that limits the overall performance, so the usual goal is to improve the bottleneck component so that the whole system can achieve the desired performance.

The process of tracking down bottlenecks (also referred as "hot spots" - sections of the code that execute most frequently - i.e. have the highest execution count) is called performance analysis. Reduction is achieved with the utilization of specialized tools such as performance analyzers or profilers, the objective being to make particular sections of code perform as effectively as possible to improve overall algorithmic efficiency.

See also
 Performance engineering
 Profiling (computer programming)
 Program optimization

References

Software optimization
Software performance management
Richard Cathcart. Richard Brook Cathcart (born 1943) is an American geographer who specializes in macro-engineering.

He is co-author of Macro-Engineering: A Challenge for the Future, published 2007 by Springer Science & Business Media.

See also
List of geographers

References

External links
About

1943 births
Living people
American geographers
Place of birth missing (living people)
Date of birth missing (living people)
Crossrail (disambiguation). Crossrail is a railway construction project in London.

Crossrail may also refer to:

 Crossrail 2, a proposed railway route across London
 Crossrail Glasgow, a proposed railway development in Central Scotland
 Aberdeen Crossrail, a proposed railway development in north-east Scotland
 Edinburgh Crossrail, a former railway service in south-east Scotland
 Crossrail Place, the structure within Canary Wharf station in London that is above the Crossrail platforms
 MTR Crossrail, the company that operates the Crossrail concession in London
Rail freight companies:
 Crossrail AG, a former rail freight company in Switzerland, with subsidiaries in Italy and Belgium
 Crossrail Benelux, a rail freight company in Belgium, subsidiary of BLS Cargo

See also
 East West Line (disambiguation)
Li Huatian. Professor Li Huatian (1922–2007) was one of the first few computer scientists in China and was well known for his early contributions to the areas of computer science and computer networks.

Life and work 
He was born on January 29, 1922 in Songjiang, Jiangsu (now Songjiang, Shanghai). He graduated from the National Southwestern Associated University with a degree in electrical engineering in 1943 and from Harvard University with a master's degree in 1948.

He returned to China in 1949 to start his research and teaching career as a university professor. He taught at Dalian University of Technology and Northeastern University. He served as the department chair of the departments of Automation and Computer Science and the university vice president at Northeastern University.

He also served as a vice president for IFAC, the International Federation of Automatic Control. He resigned administration positions in 1984 to return to full-time research and teaching. Meanwhile, he founded the first PhD program in computer science in China.

Till his final retirement in 1995, he had published numerous journal papers in areas of automatic control, computer theory, computer networks, and multimedia systems and brought up a lot of younger computer scientists in China. He also co-founded the Neusoft Group in early 1990s with his PhD student Liu Jiren. Professor Li died on January 24, 2007 in Shenzhen, China.

References

Chinese computer scientists
Theoretical computer scientists
Computer systems researchers
Harvard University alumni
Tsinghua University alumni
1922 births
2007 deaths
Educators from Shanghai
Academic staff of the Northeastern University (China)
Academic staff of Dalian University of Technology
Scientists from Shanghai
National Southwestern Associated University alumni
DirectLOGIC. DirectLOGIC is a range of programmable logic controllers produced by Koyo.

They are programmed using DirectSOFT via:
 RS-232
 USB port with USB-to-Serial adapter
 10BASE-T or 10/100 Ethernet network card

Models
 DL05 Micro PLC
 DL06 Micro Modular PLC
 DL105 Fixed I/O (brick) PLC
 DL205 Modular PLC
 DL305 Legacy PLC, compatible with the General Electric Series One, the Texas Instruments Series 305, and the Siemens SIMATIC TI305.
 DL405 Specialty PLC

See also
 SCADA

External links
 Koyo PLCs

Industrial automation
Japanese brands
Focke-Wulf Project I. 

The Focke-Wulf Project I was a design study for a jet fighter, to be built in Germany during World War II. In 1942, the Reichsluftministerium (RLM) asked Professor Kurt Tank of the Focke-Wulf factory to investigate the possibility of a single-engine jet fighter. He was given the development plans of the BMW 003, Jumo 004 and Heinkel HeS 011 engines. Late in 1942 the Project Office, led by Ludwig Mittelhuber, began to work on a series of fighter projects, to be powered by one of these new turbojet units.

The first proposed design featured a BMW P.330 2 or Jumo 004 engine, positioned on the fuselage back. The pilot was situated in the fuselage nose, and underneath were four units of armament. Its mid-wing was swept forward and the V-tail was swept back. The mainwheels of the tricycle undercarriage were so positioned under the fuselage that they could lie between themselves, when retracted.

Specifications (as designed)

See also
Emergency Fighter Program

References
 
 
 
 
 
 
 
 

Abandoned military aircraft projects of Germany
Project I
Single-engined jet aircraft
Forward-swept-wing aircraft
V-tail aircraft
Scanning Hall probe microscope. Scanning Hall probe microscope (SHPM) is a variety of a scanning probe microscope which incorporates accurate sample approach and positioning of the scanning tunnelling microscope with a semiconductor Hall sensor. Developed in 1996 by Oral, Bending and Henini, SHPM allows mapping the magnetic induction associated with a sample. Current state of the art SHPM systems utilize 2D electron gas materials (e.g. GaAs/AlGaAs) to provide high spatial resolution (~300 nm) imaging with high magnetic field sensitivity. Unlike the magnetic force microscope the SHPM provides direct quantitative information on the magnetic state of a material. The SHPM can also image magnetic induction under applied fields up to ~1 tesla and over a wide range of temperatures (millikelvins to 300 K).

The SHPM can be used to image many types of magnetic structures such as thin films, permanent magnets, MEMS structures, current carrying traces on PCBs, permalloy disks, and recording media

Advantages to other magnetic raster scanning methods

SHPM is a superior magnetic imaging technique due to many reasons.  Although MFM provides higher spatial resolution (~30 nm) imaging, unlike the MFM technique, the Hall probe exerts negligible force on the underlying magnetic structure and is noninvasive. Unlike the magnetic decoration technique, the same area can be scanned over and over again. The magnetic field caused by hall probe is so minimal it has a negligible effect on sample it is measuring. The sample does not need to be an electrical conductor, unless using STM for height control. The measurement can be performed from 5 – 500 K in ultra high vacuum (UHV) and is nondestructive to the crystal lattice or structure. Tests requires no special surface preparation or coating. The detectable magnetic field sensitivity, is approximately 0.1 uT – 10 T. SHPM can be combined with other scanning methods such as STM.

Limitations
There are some shortcomings or difficulties when working with an SHPM. High resolution scans become difficult due to the thermal noise of extremely small hall probes. There is a minimum scanning height distance due to the construction of the hall probe. (This is especially significant with 2DEG semi-conductor probes due to their multi-layer design). The scanning (lift) height affects obtained image. Scanning large areas takes a significant amount of time. There is a relatively short practical scanning range (order of 1000s micrometer) along any direction. The housing is important to shield electromagnetic noise (Faraday cage), acoustic noise (anti-vibrating tables), air flow (air isolation cupboard), and static charge on the sample (ionizing units).

References

Scanning probe microscopy
Environmental engineering law. Environmental engineering law is a profession that requires an expertise in both environmental engineering and law. This field includes professionals with both a legal and environmental engineering education. This dual educational requirement is typically satisfied through an ABET accredited degree in environmental engineering and an ABA accredited law degree. Likewise, this profession requires both licensure in professional environmental engineering and admittance to one bar.

Environmental engineering law is the professional application of law and engineering principles to improve the environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation and for other organisms, and to remediate polluted sites. Environmental engineering lawyers seek to promote the advancement of technical engineering knowledge in the legal profession and to enhance informed legal analysis of complex environmental matters.

Practice areas
Environmental engineering law professionals offer a sound knowledge base in the fields of both environmental engineering and law to address complex environmental problems which demand both professional technical practice and legal expertise. Areas of practice are continually expanding, but frequently include complex land transactions, such as: 

Brownfields redevelopment
Asbestos baseline survey and building revaluation due to forthcoming asbestos abatements
Soil contamination assessment & remediation, the development of a remedial action workplan (RAWP) and engineering controls, including an environmental land use restriction (ELUR)
Total maximum daily load (TMDL) nutrient loading studies (ex. for NPDES wastewater discharges) and regulatory negotiation of nutrients discharge limits from waste treatment plants, such as phosphorus and nitrogen.

See also
Engineering law
Environmental law
Environmental agreements
Environmental Engineering Science
Environmental impact statement
Environmental justice
International environmental law

References

Environmental engineering
Environmental law
Caproni Ca.309. The Caproni Ca.309 Ghibli was an Italian aircraft used in Libya and North Africa from 1937 to 1943. Its nickname, 'Ghibli', refers to a Libyan desert wind.

Development
The Caproni Ca.309 was designed by Cesare Pallavicino, based on the Ca.308 Borea transport. It was intended to replace the obsolete IMAM Ro.1 biplane, and to serve as a reconnaissance and ground-attack aircraft.

The Ca.309 was a low-wing cantilever monoplane with a piston engine fitted to each wing.

The aircraft was also produced in Bulgaria. That variant, 24 of which were built, was known as the Kaproni-Bulgarski KB 6/KB 309 Papagal.

Operations

The Ca.309 served in Libya during the first part of World War II with the Auto-Saharan Company, with good operational results.

After the loss of the African colonies the surviving planes were returned to Italy, where they were used as transports. Two Ghiblis were bought by the Paraguayan government for its Military Air Arm. They were used as transport planes from 1939 to 1945 and in that year they were transferred to Líneas Aéreas de Transporte Nacional (LATN), the Paraguayan first airline which was run by the Military Aviation. They were in active service until the early 1950s and later sold to a private Argentine owner.

Operators
 
 Regia Aeronautica, operated 243 Caproni Ca.309

Italian Air Force
 
 Bulgarian Air Force
 
 Paraguayan Air Arm (two Ca.309)
 Líneas Aéreas de Transporte Nacional (LATN) used two ex-Paraguayan Air Arm Ca.309s

 Norwegian army flying corps

Specifications (Ca.309 production)

Legacy
The aircraft lends its nickname to Studio Ghibli, a Japanese animation studio known for its feature films.

See also

References

Bibliography

Ca.309
1930s Italian military reconnaissance aircraft
Aircraft first flown in 1937
Low-wing aircraft
Twin piston-engined tractor aircraft
EEWH. EEWH is the green building certification system in Taiwan. EEWH comprises nine indicators that fall into four categories - ecology, energy saving, waste reduction and health - hence the name EEWH. The system was launched in 1999.

Since 2003, the indicators have been foliage; water soil content (infiltration and retention); energy savings (for the building envelope, lighting and HVAC);  emissions reduction; construction waste reduction; water conservation; garbage and sewage improvements; biodiversity; and indoor environmental quality.

EEWH has five levels: certified, bronze, silver, gold, and diamond. As of May 2008, one building (Beitou Public Library) had been rated diamond level, and one gold.

EEWH is not equivalent to LEED (Leadership in Energy and Environmental Design Green Building Rating System) in the United States, CASBEE (Comprehensive Assessment System for Building Environmental Efficiency) in Japan, and HQE in France.

See also
Sustainable architecture
Sustainable design
Sustainable engineering

References

Building energy rating
Environment of Taiwan
Sustainable building by country
East Lancs European. The East Lancs European was a step entrance single-decker bus body that was built on the Scania L113CRL chassis by East Lancashire Coachbuilders during 1995 and 1996.

A step-entrance design, it was similar in appearance to the low-floor MaxCi on the N113CRL, but had a straight window line as opposed to a stepped/sloped one.

History

A total of 79 Europeans were built, of which besides five that were purchased by Yorkshire Traction, 59 were purchased by companies owned by the British Bus group. These companies were Luton & District (taking 27), Northumbria Motor Services (20), Midland Fox (14), Clydeside 2000 (eight) and Derby City Transport (five).

The European was superseded in late 1996 by the Flyte.

References

External links

European
Single-deck buses
Step-entrance buses
Vehicles introduced in 1995
Beriev Be-2. The Beriev Be-2 (originally designated KOR-1) was a two-seat reconnaissance seaplane built for the Soviet Navy shortly before World War II. It was designed to replace the Navy's obsolete license-produced Heinkel He 55 aircraft operating from warships and shore bases.

Design and development
The Be-2 was an all-metal biplane floatplane, with two open cockpits in tandem for the pilot and observer. The wings were braced, but designed to be folded back for storage on a warship. The float arrangement consisted of  a large central float, with two smaller floats on the wings. The Be-2 was powered by a Shvetsov M-25 radial 9-cylinder air-cooled engine (a copy of the American Wright R-1820) with a rating of .

From the outset, Be-2 design exhibited serious handling difficulties and maintenance problems. However, due to the lack of a suitable alternative, the design was placed into production. A total of around 12 serial aircraft were produced. By June 1941, six KOR-1 were in the Baltic, five were in the Black Sea Fleet Air Force.

Operational history
As problems with stability on the water while taxiing, and with maintenance of the engine were never really resolved,  that in practice, the Be-2 was restricted to training and secondary roles, and was more often deployed from land than from warships as originally planned. In addition, delays with updating the Navy's cruisers meant that suitable catapults were not installed until about 1939.

With the outbreak of war with Germany, all attempts to deploy the troublesome aircraft from ships were finally abandoned. During the early years of the war, they served as shore-based reconnaissance and search/rescue aircraft on the Baltic, and with their float undercarriage replaced by wheels, some were pressed into service as strike aircraft during the Battle of Sevastopol. They were withdrawn from service in 1942.

Operators
  
 Soviet Naval Aviation

Specifications

See also

Notes

References

 
 

Biplanes
Single-engined tractor aircraft
1930s Soviet military reconnaissance aircraft
Floatplanes
Be-0002
Aircraft first flown in 1936