17,608 research outputs found
Hard coatings based on thermal spray and laser cladding
No full textS.485-491Thermal spray and laser cladding have been used to develop hard coatings. HVOF and laser glazing techniques were used to form hard and corrosion resistant coatings, using WC/Co, impregnated in Ni-Cr powder, to protect the heat exchanger tubes from fireside erosion and corrosion, while PM 20 alloy (chromium carbide in Ni-Cr powder), WC/Co in Ni-Cr powder were used to develop a very hard and friction resistant coatings for engine groves, using plasma spray and laser cladding techniques. Results indicate that an optimized composition (15-30% of WC/Co in NiCr matrix) was best to control the erosion and corrosion of heat exchanger tubes and PM 20 alloy, applied using laser cladding, gave excellent hardness and adequate wear and friction resistance.27Nr.
Low-energy standby-sparing for hard real-time systems
No full textTime-redundancy techniques are commonly used in real-time systems to achieve fault tolerance without incurring high energy overhead. However, reliability requirements of hard real-time systems that are used in safety-critical applications are so stringent that time-redundancy techniques are sometimes unable to achieve them. Standby sparing as a hardware redundancy technique can be used to meet high reliability requirements of safety-critical applications. However, conventional standby-sparing techniques are not suitable for low-energy hard real-time systems as they either impose considerable energy overheads or are not proper for hard timing constraints. In this paper we provide a technique to use standby sparing for hard real-time systems with limited energy budgets. The principal contribution of this work is an online energy management technique which is specifically developed for standby-sparing systems that are used in hard real-time applications. This technique operates at runtime and exploits dynamic slacks to reduce the energy consumption while guaranteeing hard deadlines. We compared the low-energy standby-sparing (LESS) system with a low-energy time redundancy system (from a previous work). The results show that for relaxed time constraints, the LESS system is more reliable and provides about 26% energy saving as compared to the time-redundancy system. For tight deadlines when the time redundancy system is not sufficiently reliable (for safety-critical application), the LESS system preserves its reliability but with about 49% more energy consumptio
Are lottery scratchcards a 'hard' form of gambling?
No full textThis article argues that scratchcards are not an extension of the online U.K. National Lottery but an entirely different form of gambling, with its own implications for future gambling policy. It also argues that scratchcards are potentially addictive and should be considered a 'hard' form of gambling. The author suggests that scratchcard gambling could become a repetitive habit for some people because of their integrated mix of conditioning effects, rapid event frequency, short payout intervals and psychological rewards coupled with the fact that scratchcards require no skill and are highly accessible, deceptively inexpensive and available in 'respectable' outlets. On March 21, 1995, Camelot — the consortium that runs the U.K. National Lottery online — introduced scratchcards. Like the online game, 28% of ticket sales contribute towards 'good causes' distributed by the National Lotteries Charities Board. Although scratchcards are not new to the United Kingdom, many people view them as intricately linked with the National Lottery. Camelot's scratchcards were the first to benefit from both heavy advertising (television, national newspapers, billboards, etc.) and large jackpots (e.g., £50,000), which meant they became successful very quickly
Annual report (Arizona Commission for the Deaf and the Hard of Hearing)
No full textThe Arizona Commission for the Deaf and the Hard of Hearing was established in 1977 to improve the quality of life for deaf and hard of hearing residents. It serves as a statewide information referral center for issues related to people with hearing loss, oversees the Arizona Relay Service, the Telecommunications Equipment Distribution Program and licenses American Sign Language Interpreters. The agency serves citizens who are deaf- blind and who have speech difficulties as well. The agency name was changed in 1985 to the Arizona Council for the Hearing Impaired, and in 2000 was again changed to its present name. The Commission aspires to be a national leader in communication access, support services and community empowerment throughout the state
Hard coal and brown coal mining in the Czech Republic
No full textZasoby węgla w Republice Czeskiej są ocenione na 10 mld ton – w tym 37% węgla kamiennego, 60% węgla brunatnego i 3% lignitu. Węgiel kamienny jest wydobywany w północnych Morawach, w 2017 roku produkcja wyniosła 5,5 mln ton. Węgiel brunatny jest eksploatowany głównie w północno-zachodnich Czechach, produkcja węgla brunatnego wyniosła w 2017 roku 38,1 mln ton. Znaczne ilości węgla kamiennego są eksportowane do Słowacji, Austrii, Niemiec i Węgier Zgodnie z polityką energetyczną państwa węgiel pozostanie głównym źródłem energii w kraju w przyszłości, pomimo zwiększonego wykorzystania energii jądrowej i gazu ziemnego. Rząd oczekuje, że w 2030 r. energia z węgla będzie stanowić 30,5% produkowanej energii. W Republice Czeskiej działa pięć przedsiębiorstw węglowych: OKD, a.s., jedyny producent węgla kamiennego oraz cztery firmy wydobywcze węgla brunatnego Severočeské Doly a.s., których właścicielem jest ČEZ, największy producent węgla brunatnego, Vršanská uhelná a.s., z zasobami węgla do 2055 roku, Severní energetická a.s. z największymi rezerwami węgla brunatnego w Republice Czeskiej i Sokolovska uhelná a.s., najmniejsza spółka górnicza wydobywającą węgiel brunatny. OKD eksploatuje węgiel kamienny w dwu kopalniach Kopalnia Důlní závod 1 – Ruch ČSA, Ruch Lazy, Ruch Darkov oraz Kopalnia Důlní závod 2 (Ruch Sever, Ruch Jih). A artykule przedstawiono również proekologiczne rozwiązanie zagospodarowania hałd odpadów po wzbogacaniu węgla – zakład wzbogacania odpadów weglowych z hałdy Hermanice.Coal reserves in the Czech Republic are estimated to be 10 billion tons – hard coal about 37%, brown coal about 60% and lignite 3%. Hard coal is produced in Northern Moravia. In 2017 the production of hard coal was 5.5 million tons. Brown coal is mined in North-Western Bohemia − the production of brown coal in 2017 was 38.1 million tons. Significant quantities of hard coal are exported to: Slovakia, Austria, Germany and Hungary. In accordance with the National Energy Policy, coal will remain the main source of energy in the country in the future, despite the increased use of nuclear energy and natural gas. The government expects that in 2030 energy from coal will account for 30.5% of energy produced. There are five coal companies in the Czech Republic: OKD, a.s., the only hard coal producer and four brown coal mining companies: Severočeské Doly a.s., owned by ČEZ, the largest producer of brown coal, Vršanská uhelná a.s., with coal resources until 2055, Severní energetická a.s. with the largest brown coal reserves in the Czech Republic and Sokolovska uhelná a.s., the smallest mining company extracting lignite. OKD operates coal in two mines Kopalnia Důlní závod 1 – (consists of three mines: ČSA Mine, Lazy Mine, Darkov Mine) and Mine Důlní závod 2 (ttwo mines Sever, Jih). The article also presents a pro-ecological solution for the management of waste heaps after coal enrichment – a plant for the enrichment of coal waste from the Hermanice heap
Integrable families of hard-core particles with unequal masses in a one-dimensional harmonic trap
No full textWe show that the dynamics of particles in a one-dimensional harmonic trap with hard-core interactions can be solvable for certain arrangements of unequal masses. For any number of particles, there exist two familiesofunequalmassparticlesthat haveintegrabledynamics,andthereareadditionalexceptionalcases for three, four, and five particles. The integrable mass families are classified by Coxeter reflection groups and the corresponding solutions are Bethe-ansatz-like superpositions of hyperspherical harmonics in the relative hyperangular coordinates that are then restricted to sectors of fixed particle order. We also provide evidence for superintegrability of these Coxeter mass families and conjecture maximal superintegrability
Hard Times
No full textA song about the poor wishing away hard times.https://egrove.olemiss.edu/kgbsides_uk/1643/thumbnail.jp
Rapid X-ray variability properties during the unusual very hard state in neutron-star low-mass X-ray binaries
No full textHere, we study the rapid X-ray variability (using XMM–Newton observations) of three neutron-star low-mass X-ray binaries (1RXS J180408.9−342058, EXO 1745−248 and IGR J18245−2452) during their recently proposed very hard spectral state. All our systems exhibit a strong to very strong noise component in their power density spectra (rms amplitudes ranging from 34 per cent to 102 per cent) with very low characteristic frequencies (as low as 0.01 Hz). These properties are more extreme than what is commonly observed in the canonical hard state of neutron-star low-mass X-ray binaries observed at X-ray luminosities similar to those we observe from our sources. This suggests that indeed the very hard state is a spectral-timing state distinct from the hard state, although we argue that the variability behaviour of IGR J18245−2452 is very extreme and possibly this source was in a very unusual state. We also compare our results with the rapid X-ray variability of the accreting millisecond X-ray pulsars IGR J00291+5934 and Swift J0911.9−6452 (also using XMM–Newton data) for which previously similar variability phenomena were observed. Although their energy spectra (as observed using the Swift X-ray telescope) were not necessarily as hard (i.e. for Swift J0911.9−6452) as for our other three sources, we conclude that likely both sources were also in very similar state during their XMM–Newton observations. This suggests that different sources that are found in this new state might exhibit different spectral hardness and one has to study both the spectral and the rapid variability to identify this unusual state
Hard fighting : Israel in Lebanon and Gaza /
No full textLike Israel in 2006, the United States today is likely ill prepared for hybrid warfare. To identify lessons that the U.S. military might learn from the Israeli experience in Lebanon, the author examines the state of the Israeli military before the Second Lebanon War, the lessons it learned during that conflict, the reforms it undertook to address its deficiencies, and how it fared during Operation Cast Lead three years later."Prepared for the United States Army and the United States Air Force."Includes bibliographical references and index.Like Israel in 2006, the United States today is likely ill prepared for hybrid warfare. To identify lessons that the U.S. military might learn from the Israeli experience in Lebanon, the author examines the state of the Israeli military before the Second Lebanon War, the lessons it learned during that conflict, the reforms it undertook to address its deficiencies, and how it fared during Operation Cast Lead three years later.Introduction -- The Second Lebanon war -- Operation Cast Lead -- The relevance of the Israeli experience for the U.S. Joint Force -- Appendix: Timeline of the 2006 Second Lebanon war.JSTO
Galactic black holes in the hard state, a multiwavelength view of accretion and ejection
No full textThe canonical hard state is associated with emission from all three fundamental accretion components: the accretion disk, the hot accretion disk corona and the jet. On top of these, the hard state also hosts very rich temporal variability properties (low frequency QPOs in the PDS, time lags, long time scale evolution). Our group has been working on the major questions of the hard state both observationally (with multi-wavelength campaigns using RXTE, SWIFT, SUZAKU, SPITZER, VLA, ATCA, SMARTS) and theoretically (through jet models that can fit entire SEDs). Through spectral and temporal analysis we seek to determine the geometry of accretion components, and relate the geometry to the formation and emission from a jet. In this presentation I will review the recent
contributions of our group to the field, including the SWIFT results on the disk geometry at low accretion rates, the jet model fits to the hard state SEDs (including SPITZER data) of GRO J 1655-40, and the final results on the evolution of spectral (including X-ray, radio and infrared) and temporal
properties of selected black holes in the hard states. I will also talk about impact of ASTROSAT to the science objectives of our group
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