WorldWideScience

Sample records for brinell hardness

  1. Standard hardness conversion tables for metals relationship among brinell hardness, vickers hardness, rockwell hardness, superficial hardness, knoop hardness, and scleroscope hardness

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 Conversion Table 1 presents data in the Rockwell C hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.2 Conversion Table 2 presents data in the Rockwell B hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.3 Conversion Table 3 presents data on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, and Knoop hardness of nickel and high-nickel alloys (nickel content o...

  2. Characterization of diamond adhesion on micro-grain WC-Co substrates using Brinell indentations and micro-Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ali, N [Centre for Mechanical Technology and Automation, University of Aveiro, 3810-193 Aveiro (Portugal); Cabral, G [Centre for Mechanical Technology and Automation, University of Aveiro, 3810-193 Aveiro (Portugal); Titus, E [Centre for Mechanical Technology and Automation, University of Aveiro, 3810-193 Aveiro (Portugal); Ogwu, A A [Thin Film Centre, University of Paisley, PA1 2BE (United Kingdom); Gracio, J [Centre for Mechanical Technology and Automation, University of Aveiro, 3810-193 Aveiro (Portugal)

    2004-09-22

    In this study, we investigate the adhesion of diamond coatings deposited on 0.8 {mu}m WC-10% Co substrates using chemical vapour deposition (CVD). Polycrystalline diamond films were deposited using (i) constant methane (CH{sub 4}) flow, at 3 and 4.5 sccm, and (ii) modulated CH{sub 4} flow at 4.5 and 3 sccm for 8 and 10 min, respectively. Constant CH{sub 4} flow into the vacuum chamber during diamond CVD is the conventional approach to deposit diamond onto a range of substrate materials. The timed CH{sub 4} modulations are an integral part of our recently proposed process called time-modulated CVD (TMCVD). The coating adhesion was characterized using indentation tests employing a Brinell indenter. In this study, we employ three indentation loads: 294, 490 and 612.5 N. In addition, micro-Raman spectroscopy was used to (i) characterize the deposited films for diamond-carbon phase purity and (ii) determine the biaxial stresses in the coating samples. In this paper, we correlate the adhesion strength of diamond films to biaxial stresses. No lateral cracking occurred in diamond films deposited by the TMCVD process after a 294 N load indentation. This result coupled with the complementary stress calculations indicates a higher film-substrate adhesion in time-modulated films. Our findings suggest that at higher indentation loads the response from and the behaviour of the substrate need to be considered in determining the coating adhesion strength. The TMCVD process promotes secondary nano-sized diamond crystallites during the higher timed methane modulations. It is expected that the mechanical interlock at the film/substrate interface is higher for film coatings deposited using TMCVD, thus resulting in the improved adhesion of the time-modulated coating on WC-Co.

  3. The influence of cooling rate on the hardness of cast iron with nodular and vermicular graphite

    OpenAIRE

    M.S. Soiński; B. Zatoń; A. Skoczylas; A. Derda

    2008-01-01

    The paper presents hardness changes for cast iron with nodular and vermicular graphite, determined within the separately cast test blocks. Investigation has comprised cast irons with similar ferrite and pearlite fractions in the metal matrix. The hardness measurements have been performed by Brinell method for samples taken both from an edge and from the centre of a Y block (for nodular cast iron) or of a reversed U block (in the case of vermicular cast iron). Investigations have pertained bot...

  4. The influence of cooling rate on the hardness of cast iron with nodular and vermicular graphite

    Directory of Open Access Journals (Sweden)

    M. S. Soiński

    2008-12-01

    Full Text Available The paper presents hardness changes for cast iron with nodular and vermicular graphite, determined within the separately cast test blocks. Investigation has comprised cast irons with similar ferrite and pearlite fractions in the metal matrix. The hardness measurements have been performed by Brinell method for samples taken both from an edge and from the centre of a Y block (for nodular cast iron or of a reversed U block (in the case of vermicular cast iron. Investigations have pertained both to the test parts and to the sinkheads of the test blocks. Hardness measurements have been completed with metallographic examination.

  5. Superelastic Ball Bearings: Materials and Design to Avoid Mounting and Dismounting Brinell Damage in an Inaccessible Press-Fit Application-. I ; Design Approach

    Science.gov (United States)

    Dellacorte, Christopher; Howard, S. Adam

    2015-01-01

    Ball bearings require proper fit and installation into machinery structures (onto shafts and into bearing housings) to ensure optimal performance. For some applications, both the inner and outer race must be mounted with an interference fit and care must be taken during assembly and disassembly to avoid placing heavy static loads between the balls and races otherwise Brinell dent type damage can occur. In this paper, a highly dent resistant superelastic alloy, 60NiTi, is considered for rolling element bearing applications that encounter excessive static axial loading during assembly or disassembly. A small (R8) ball bearing is designed for an application in which access to the bearing races to apply disassembly tools is precluded. First Principles analyses show that by careful selection of materials, raceway curvature and land geometry, a bearing can be designed that allows blind assembly and disassembly without incurring raceway damage due to ball denting. Though such blind assembly applications are uncommon, the availability of bearings with unusually high static load capability may enable more such applications with additional benefits, especially for miniature bearings.

  6. [Preparation of hard crown and bridge resin without PMMA powder (author's transl)].

    Science.gov (United States)

    Nagata, K; Suzuki, S; Nakabayashi, N; Masuhara, E

    1979-01-01

    Elimination of PMMA powder to prepare better hard crown and bridge resin had been pointed out by the authors even though polyfunctional methacrylates were used. Application of hydrophobic coloidal silica instead of PMMA pearl with triethyleneglycol dimethacrylate and Bis-GMA was studied. Polyermization was carried out in the hot air stream at 120 degrees approximately 130 degrees C or in a pressure vessel at 4.5 kg/cm2 gauge, 100 degrees C. Mechanical properties, brinell hardness, compressive strength, an amount of water sorption, comparative average abrasion loss depth with those of PMMA, were measured. They were improved very much by this new system. PMID:221600

  7. Superelastic Ball Bearings: Materials and Design to Avoid Mounting and Dismounting Brinell Damage in an Inaccessible Press-fit Application-. II; Detailed Analysis

    Science.gov (United States)

    Howard, S. Adam; Dellacorte, Christopher

    2015-01-01

    Rolling element bearings utilized in precision rotating machines require proper alignment, preload, and interference fits to ensure overall optimum performance. Hence, careful attention must be given to bearing installation and disassembly procedures to ensure the above conditions are met. Usually, machines are designed in such a way that bearings can be pressed into housings or onto shafts through the races without loading the rolling elements. However, in some instances, either due to limited size or access, a bearing must be installed or removed in such a way that the load path travels through the rolling elements. This can cause high contact stresses between the rolling elements and the races and introduces the potential for Brinell denting of the races. This paper is a companion to the Part I paper by the authors that discusses material selection and the general design philosophy for the bearing. Here, a more in-depth treatment is given to the design of a dent-resistant bearing utilizing a superelastic alloy, 60NiTi, for the races. A common bearing analysis tool based on rigid body dynamics is used in combination with finite element simulations to design the superelastic bearing. The primary design constraints are prevention of denting and avoiding the balls riding over the edge of the race groove during a blind disassembly process where the load passes through the rolling elements. Through an iterative process, the resulting bearing geometry is tailored to improve axial static load capability compared to a deep-groove ball bearing of the same size. The results suggest that careful selection of materials and bearing geometry can enable blind disassembly without damage to the raceways, which is necessary in the current application (a compressor in the International Space Station Environmental Control and Life Support System), and results in potential design flexibility for other applications, especially small machines with miniature bearings.

  8. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  9. The water absorption effect on the hardness of composites polyester

    Science.gov (United States)

    Mohammed, A. A.; Issa, T. T.

    2016-04-01

    Unsaturated polyester resin (UPE) was used as the matrix .The iron woven wire and E-glass fiber type (0 - 9°), were used as a reinforcements additives of weight percentage (5, 10, 15) respectively. Samples were prepared by the hand lay-up method for (UPE), (UPE -Fe) and (UPE- Glass). Chemical analysis was used to identify the composition of Fe wire. Water immersing at room temperature for all samples were done at (2, 5, 7, 9, 12) days. Hardness test (Brinell) showed decreasing with increasing in immersion time for (UPE) from (67) HB to (95) HP after adding the reinforcement Fe fibers, with increasing in the water absorbed content especially in the days (2, 5). The water content of absorption was found to be either decreasing or increasing depending on the number of reinforcing layers added.

  10. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    In the fields of power conversion devices and broadcasting/communication amplifiers, high power, high frequency and low losses are desirable. Further, for electronic elements in aerospace/aeronautical/geothermal surveys, etc., heat resistance to 500degC is required. Devices which respond to such hard specifications are called hard electronic devices. However, with Si which is at the core of the present electronics, the specifications cannot fully be fulfilled because of the restrictions arising from physical values. Accordingly, taking up new device materials/structures necessary to construct hard electronics, technologies to develop these to a level of IC were examined and studied. They are a technology to make devices/IC of new semiconductors such as SiC, diamond, etc. which can handle higher temperature, higher power and higher frequency than Si and also is possible of reducing losses, a technology to make devices of hard semiconducter materials such as a vacuum microelectronics technology using ultra-micro/high-luminance electronic emitter using negative electron affinity which diamond, etc. have, a technology to make devices of oxides which have various electric properties, etc. 321 refs., 194 figs., 8 tabs.

  11. Electrical conductivity and hardness of ternary Ge-In-Sb alloys and calculation of the isothermal section at 300 C

    Energy Technology Data Exchange (ETDEWEB)

    Premovic, Milena; Minic, Dusko; Mitrovica, Kosovska [Pristina Univ., Kosovska Mitrovica (Serbia). Faculty of Technical Science; Manasijevic, Ivana; Zivkovic, Dragana [Belgrade Univ., Bor (Serbia). Dept. of Metallurgical Engineering

    2015-07-01

    This publication presents results of experimental investigation and thermodynamic calculation of the ternary Ge-In-Sb system. Isothermal section of the Ge-In-Sb system at 300 C has been extrapolated using optimized thermodynamic parameters for the constitutive binary systems. Microstructure analysis was carried out by light microscope, scanning electron microscopy with energy dispersive spectrometry and X-ray powder diffraction methods and obtained results were compared with predicted phase equilibria. Hardness of selected alloys annealed at 300 C was measured using Vickers microhardness test and Brinell hardness test. Electrical conductivity of a number of alloys annealed at 300 C was experimentally determined. Good overall agreement between experimental and calculated values was obtained.

  12. Radiation Hardness of Some Polymers and Epoxy Glues

    CERN Document Server

    Gladkikh, S N; Kekelidze, G D; Mishin, S V; Peshekhonov, V D

    2001-01-01

    The radiation hardness of polysulphone and polycarbonate and also epoxy glues ELK-5 and CMK-5 was studied. This organic materials are being used for production of coordinate detectors. With that end in view dependences of maximum and maximum permissible loads and Brinell hardness on the absorbed doze for polymers were studied. For glues dependences of breaking point and relative lengthening on the stretching were studied. Irradiations were carried out on the experimental reactors providing a stream of fast neutrons with an energy spectrum in a range 0.1-20 MeV. Average energy of a \\gamma-component of a beam was 1.5-2 MeV and maximal one was up to 9 MeV. The maximal absorbed doze for glues was \\sim 100 kGy and for polymers was \\sim 1000 kGy. Results of measurements have shown weak dependence of mechanical properties of the investigated polymers and glues on the absorbed doze that allows to use them for detectors production within the framework of LHC project.

  13. Hard coatings

    OpenAIRE

    Dan, J.; Boving, H.; Hintermann, H.

    1993-01-01

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many process...

  14. Effects of solution heat treatment on the microstructure and hardness of Mg-5Li-3Al-2Zn-2Cu alloy

    International Nuclear Information System (INIS)

    The microstructure and hardness of Mg-5Li-3Al-2Zn-2Cu alloy were investigated both in the as-cast condition and after solution heat treatment at 330-390 deg. C for 5 h. The as-cast alloy contains a microstructure consisting of α-Mg matrix, AlLi phase, AlCuMg phase and Al2Cu phase. After the solution heat treament, the AlLi phase was dissolved into the matrix, however, the AlCuMg and Al2Cu phases were not dissolved. With the increase of solution temperature, almost all the AlLi phase was dissolved, and the effects of solution strengthening of Al and Li atoms in the alloy increase, which results in the gradual increase of the Brinell hardness of the solution-treated alloy.

  15. Hard coatings

    International Nuclear Information System (INIS)

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many processes have been developed which are variations and/or combinations of the basic CVD and PVD methods. The main difference between these two families of deposition techniques is that the CVD is an elevated temperature process (≥ 700 C), while the PVD on the contrary, is rather a low temperature process (≤ 500 C); this of course influences the choice of substrates and properties of the coating/substrate systems. Fundamental aspects of the vapor phase deposition techniques and some of their influences on coating properties will be discussed, as well as the very important interactions between deposit and substrate: diffusions, internal stress, etc. Advantages and limitations of CVD and PVD respectively will briefly be reviewed and examples of applications of the layers will be given. Parallel to the development and permanent updating of surface modification technologies, an effort was made to create novel characterisation methods. A close look will be given to the coating adherence control by means of the scratch test, at the coating hardness measurement by means of nanoindentation, at the coating wear resistance by means of a pin-on-disc tribometer, and at the surface quality evaluation by Atomic Force Microscopy (AFM). Finally, main important trends will be highlighted. (orig.)

  16. Evaluation of applicability on multi-axis residual stress formed by hard sphere indentation for stress corrosion cracking test

    International Nuclear Information System (INIS)

    A multi-axis stress field is indispensable for quick and quantitative evaluation of stress corrosion cracking for constructional materials and weld joints of existing industrial plants. The applicability of multi-axis residual stress field formed by pushing of a hard sphere ball made of WC into stress corrosion cracking tests was evaluated. The Brinell type hard sphere ball was stuffed into small flat-plate of type 304SS. The residual stress and displacement around the indentation were measured using an X-ray diffraction method and a displacement meter. Numerical analysis by the finite element method was conducted in order to compare with the experimental results. The numerical analysis was comparatively in agreement with the experimental results. A hard sphere ball diameter, a specimen holder hole diameter, specimen thickness, and an indentation depth were selected by numerical analysis to optimize the residual stress of specimen. The stress corrosion cracking test in chloride solution was performed using the specimen with optical residual stress condition. It is confirmed that the multi-axis residual stress field was useful in quick and quantitative stress corrosion cracking test by comparing the initiation of cracks with the distribution of residual stress obtained by numerical analysis. (author)

  17. Hard hadronic diffraction is not hard

    CERN Document Server

    Kopeliovich, Boris; Potashnikova, Irina

    2016-01-01

    Hadronic diffractive processes characterised by a hard scale (hard diffraction) contain a nontrivial interplay of hard and soft, nonperturbative interactions, which breaks down factorisation of short and long distances. On the contrary to the expectations based on the factorization hypothesis, assuming that hard diffraction is a higher twist, these processes should be classified as a leading twist. We overview various implications of this important observation for diffractive radiation of Abelian (Drell-Yan, gauge bosons, Higgs boson) and non-Abelian (heavy flavors) particles, as well as direct coalescence into the Higgs boson of the non-perturbative intrinsic heavy flavour component of the hadronic wave function.

  18. A study on hardness behavior of geopolymer paste in different condition

    Science.gov (United States)

    Zainal, Farah Farhana; Hussin, Kamarudin; Rahmat, Azmi; Abdullah, Mohd Mustafa Al Bakri; Shamsudin, Shaiful Rizam

    2016-07-01

    This study has been conducted to understand the hardness behavior of geopolymer paste in different conditions; with and without being immersed in water. Geopolymer paste has been used nowadays as an alternative way to reduce global warming pollution by carbon dioxide (CO2) released to the air caused from the production of Ordinary Portland Cement (OPC). Geopolymer has many advantages such as high compressive strength, lower water absorption and lower porosity. Geopolymer paste in this study was made from a mixture of fly ash and alkaline activators. The alkaline activators that have been used were sodium hydroxide (NaOH) solution and sodium silicate (Na2SiO3) solution. Then the mixture was allowed to harden for 24hrs at ambient temperature and then placed in the oven for 24hrs with 60°C for the curing process. The hardness testing was conducted after a few months when the samples already achieved the optimum design. The samples were divided to two conditions; without immersion which was placed at ambient temperature (S1) and immersed in water for one week (S2). The samples then are divided into two at the center and testing was conducted into 4 parts which are part 1, part 2, part 3 and part 4. Various methods of non-destructively testing concrete and mortar have been in use for many years such as Vickers hardness test, Rockwell hardness test, Brinell hardness test and many more. The Rockwell hardness test method as defined in ASTM E-18 is the most commonly used hardness test method which is also used in this study. From the results, S1 has higher hardness value than S2 for all parts with the maximum value of S1 is 118.6 and the minimum value is 71.8. The maximum value of S2 is 114.4 and the minimum value is 0. The central part of the geopolymer paste also showed greater hardness values than the edge area of the samples.

  19. Ordering of hard particles between hard walls

    Science.gov (United States)

    Chrzanowska, A.; Teixeira, P. I. C.; Ehrentraut, H.; Cleaver, D. J.

    2001-05-01

    The structure of a fluid of hard Gaussian overlap particles of elongation κ = 5, confined between two hard walls, has been calculated from density-functional theory and Monte Carlo simulations. By using the exact expression for the excluded volume kernel (Velasco E and Mederos L 1998 J. Chem. Phys. 109 2361) and solving the appropriate Euler-Lagrange equation entirely numerically, we have been able to extend our theoretical predictions into the nematic phase, which had up till now remained relatively unexplored due to the high computational cost. Simulation reveals a rich adsorption behaviour with increasing bulk density, which is described semi-quantitatively by the theory without any adjustable parameters.

  20. Effects of particulate reinforcement and heat treatment on the hardness and wear properties of AA 2024-MoSi2 nanocomposites

    International Nuclear Information System (INIS)

    Research highlights: → Synthesis of 2024-MoSi2 nanocomposite using mechanical alloying procedure. → Effect of aging heat treatment on the hardness improvement of the nanocomposites. → Effect of aging treatment on the wear behavior of the aluminum matrix nanocomposites. → The limitation of adding nanoscale reinforcement to the aluminum alloys. -- Abstract: In this study, nanocomposites of AA 2024 aluminum alloy matrix reinforced with different volume fractions of nanometric MoSi2 intermetallic particles ranging from 0 to 5%, were produced using mechanical alloying technique. For comparison, samples without reinforcing particles and mechanical alloying and a sample with micrometric MoSi2 particles were also synthesized. The prepared composite powders were consolidated by cold and hot pressing and then heat treated to solution and aged condition (T6). The effects of MoSi2 particle size, volume fraction and also heat treatment on the hardness and wear properties of the composites were investigated using Brinell hardness and pin-on-disc wear tests. The results indicated that although T6 heat treatment increases the hardness of all samples compared to as hot-pressed (HP) condition, the age-hardenability (aging induced hardness improvement) decreases after mechanical alloying and with increasing MoSi2 volume fraction due to the high dislocation density produced during mechanical alloying. With increasing the volume fraction of nano-sized MoSi2 particles up to 3-4%, the hardness of the composites continuously increases and then declines most probably due to the particle agglomeration. The wear sliding test disclosed that the wear resistance of all specimens in T6 condition is higher than that of HP condition and increases with increasing MoSi2 content. Scanning electron microscopic observation of the worn surfaces was conducted and the dominant wear mechanism was recognized as abrasive wear accompanied by some adhesive wear mechanism.

  1. Comprehensive hard materials

    CERN Document Server

    2014-01-01

    Comprehensive Hard Materials deals with the production, uses and properties of the carbides, nitrides and borides of these metals and those of titanium, as well as tools of ceramics, the superhard boron nitrides and diamond and related compounds. Articles include the technologies of powder production (including their precursor materials), milling, granulation, cold and hot compaction, sintering, hot isostatic pressing, hot-pressing, injection moulding, as well as on the coating technologies for refractory metals, hard metals and hard materials. The characterization, testing, quality assurance and applications are also covered. Comprehensive Hard Materials provides meaningful insights on materials at the leading edge of technology. It aids continued research and development of these materials and as such it is a critical information resource to academics and industry professionals facing the technological challenges of the future. Hard materials operate at the leading edge of technology, and continued res...

  2. Hardness and excitation energy

    Indian Academy of Sciences (India)

    Á Nagy

    2005-09-01

    The concept of the ensemble Kohn-Sham hardness is introduced. It is shown that the first excitation energy can be given by the Kohn-Sham hardness (i.e. the energy difference of the ground-state lowest unoccupied and highest occupied levels) plus an extra term coming from the partial derivative of the ensemble exchange-correlation energy with respect to the weighting factor in the limit → 0. It is proposed that the first excitation energy can be used as a reactivity index instead of the hardness.

  3. Induced spherococcoid hard wheat

    International Nuclear Information System (INIS)

    A mutant has been obtained - a spheroccocoid line -through irradiation of hard wheat seed with fast neutrons. It is distinguished by semispherical glumes and smaller grain; the plants have low stem with erect leaves but with shorter spikes and with lesser number of spikelets than those of the initial cultivar. Good productive tillering and resistance to lodging contributed to 23.5% higher yield. The line was superior to the standard and the initial cultivars by 14.2% as regards protein content, and by up to 22.8% - as to flour gluten. It has been successfully used in hybridization producing high-yielding hard wheat lines resistant to lodging, with good technological and other indicators. The possibility stated is of obtaining a spherococcoid mutant in tetraploid (hard) wheat out of the D-genome as well as its being suited to hard wheat breeding to enhance protein content, resistance to lodging, etc. (author)

  4. Hard probes 2006 Asilomar

    CERN Multimedia

    2006-01-01

    "The second international conference on hard and electromagnetic probes of high-energy nuclear collisions was held June 9 to 16, 2006 at the Asilomar Conference grounds in Pacific Grove, California" (photo and 1/2 page)

  5. Hard coal; Steinkohle

    Energy Technology Data Exchange (ETDEWEB)

    Loo, Kai van de; Sitte, Andreas-Peter [Gesamtverband Steinkohle e.V., Herne (Germany)

    2013-04-01

    The year 2012 benefited from a growth of the consumption of hard coal at the national level as well as at the international level. Worldwide, the hard coal still is the number one energy source for power generation. This leads to an increasing demand for power plant coal. In this year, the conversion of hard coal into electricity also increases in this year. In contrast to this, the demand for coking coal as well as for coke of the steel industry is still declining depending on the market conditions. The enhanced utilization of coal for the domestic power generation is due to the reduction of the nuclear power from a relatively bad year for wind power as well as reduced import prices and low CO{sub 2} prices. Both justify a significant price advantage for coal in comparison to the utilisation of natural gas in power plants. This was mainly due to the price erosion of the inexpensive US coal which partly was replaced by the expansion of shale gas on the domestic market. As a result of this, the inexpensive US coal looked for an outlet for sales in Europe. The domestic hard coal has continued the process of adaptation and phase-out as scheduled. Two further hard coal mines were decommissioned in the year 2012. RAG Aktiengesellschaft (Herne, Federal Republic of Germany) running the hard coal mining in this country begins with the preparations for the activities after the time of mining.

  6. Hardness of metallic crystals

    Indian Academy of Sciences (India)

    Wuhui Li; Fengzhang Ren; Juanhua Su; Zhanhong Ma; Ke Cao; Baohong Tian

    2011-07-01

    This paper presents a new formula for calculating the hardness of metallic crystals, resulted from the research on the critical grain size with stable dislocations. The formula is = 6 /[(1 – )], where is the hardness, the coefficient, the shear modulus, the Poisson’s ratio, a function of the radius of an atom () and the electron density at the atom interface (). The formula will not only be used to testify the critical grain size with stable dislocations, but also play an important role in the understanding of mechanical properties of nanocrystalline metals.

  7. Hard exclusive QCD processes

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, W.

    2007-01-15

    Hard exclusive processes in high energy electron proton scattering offer the opportunity to get access to a new generation of parton distributions, the so-called generalized parton distributions (GPDs). This functions provide more detailed informations about the structure of the nucleon than the usual PDFs obtained from DIS. In this work we present a detailed analysis of exclusive processes, especially of hard exclusive meson production. We investigated the influence of exclusive produced mesons on the semi-inclusive production of mesons at fixed target experiments like HERMES. Further we give a detailed analysis of higher order corrections (NLO) for the exclusive production of mesons in a very broad range of kinematics. (orig.)

  8. Session: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  9. Running in Hard Times

    Science.gov (United States)

    Berry, John N., III

    2009-01-01

    Roberta Stevens and Kent Oliver are campaigning hard for the presidency of the American Library Association (ALA). Stevens is outreach projects and partnerships officer at the Library of Congress. Oliver is executive director of the Stark County District Library in Canton, Ohio. They have debated, discussed, and posted web sites, Facebook pages,…

  10. Rock-hard coatings

    NARCIS (Netherlands)

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has sign

  11. Dragline roller track improvement. Volume I. Evaluation of low hardness dragline track materials in rolling contact. Final report, September 30, 1976-July 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Dunfee, J.; Leonard, L.; Rumbarger, J.

    1980-01-01

    The Franklin Research Center (FRC), a Division of the Franklin Institute, was contracted by the Bureau of Mines to improve walking dragline roller tracks. The contract was subsequently transferred to the Department of Energy. The period from September 1977 to September 1978 covered laboratory rolling contact rig tests to evaluate typical low hardness dragline track materials. The results of this work are covered by DOE/ET/9121-1 Final Report, Volume I. The period from September 1978 to July 1980 covered field measurements of dragline roller circle loadings. The results of this work are covered by DOE/ET/9121-2 Final Report, Volume II. The laboratory rolling contact rig test results indicate that forged vacuum degassed air melt steel materials are recommended over air-melt cast materials for rollers and tracks. The steels tested exhibited good freedom from sensitivity to stress raisers like brinell marks and small holes or discontinuities (Volume I). The largest unknown in a recommended method for life testing roller tracks is the condition of the upper rotating frame structure and the lower tub supporting structure.

  12. Theory of hard photoproduction

    International Nuclear Information System (INIS)

    The present theoretical knowledge about photons and hard photoproduction processes, i.e. the production of jets, light and heavy hadrons, quarkonia, and prompt photons in photon-photon and photon-hadron collisions, is reviewed. Virtual and polarized photons and prompt photon production in hadron collisions are also discussed. The most important leading and next-to-leading order QCD results are compiled in analytic form. A large variety of numerical predictions is compared to data from TRISTAN, LEP, and HERA and extended to future electron and muon colliders. The sources of all relevant results are collected in a rich bibliography. (orig.)

  13. Hard exclusive pion leptoproduction

    CERN Document Server

    Kroll, Peter

    2016-01-01

    In this talk it is reported on an analysis of hard exclusive leptoproduction of pions within the handbag approach. It is argued that recent measurements of this process performed by HERMES and CLAS clearly indicate the occurrence of strong contributions from transversely polarized photons. Within the handbag approach such gamma*_T -> pi transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. It is shown that the handbag approach leads to results on cross sections and single-spin asymmetries in fair agreement with experiment. Predictions for other pseudoscalar meson channels are also briefly discussed.8 pages

  14. Hard and Soft Governance

    DEFF Research Database (Denmark)

    Moos, Lejf

    2009-01-01

    The governance and leadership at transnational, national and school level seem to be converging into a number of isomorphic forms as we see a tendency towards substituting 'hard' forms of governance, that are legally binding, with 'soft' forms based on persuasion and advice. This article analyses...... and discusses governance forms at several levels. The first layer is the global: the methods of 'soft governance' that are being utilised by transnational agencies. The second layer is the national and local: the shift in national and local governance seen in many countries, but here demonstrated in...... the case of Denmark, and finally the third layer: the leadership used in Danish schools. The use of 'soft governance' is shifting the focus of governance and leadership from decisions towards influence and power and thus shifting the focus of the processes from the decision-making itself towards more...

  15. Hard photoproduction at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier / CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)

    2007-07-01

    In view of possible photoproduction studies in ultra-peripheral heavy-ion collisions at the LHC, we briefly review the present theoretical understanding of photons and hard photoproduction processes at HERA, discussing the production of jets, light and heavy hadrons, quarkonia, and prompt photons. We address in particular the extraction of the strong coupling constant from photon structure function and inclusive jet measurements, the infrared safety and computing time of jet definitions, the sensitivity of di-jet cross sections on the parton densities in the photon, factorization breaking in diffractive di-jet production, the treatment of the heavy-quark mass in charm production, the relevance of the color-octet mechanism for quarkonium production, and isolation criteria for prompt photons. (author)

  16. Overview: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  17. Overview: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  18. Overview - Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  19. Hard coal; Steinkohle

    Energy Technology Data Exchange (ETDEWEB)

    Loo, Kai van de; Sitte, Andreas-Peter [Gesamtverband Steinkohle e.V. (GVSt), Herne (Germany)

    2015-07-01

    International the coal market in 2014 was the first time in a long time in a period of stagnation. In Germany, the coal consumption decreased even significantly, mainly due to the decrease in power generation. Here the national energy transition has now been noticable affected negative for coal use. The political guidances can expect a further significant downward movement for the future. In the present phase-out process of the German hard coal industry with still three active mines there was in 2014 no decommissioning. But the next is at the end of 2015, and the plans for the time after mining have been continued. [German] International war der Markt fuer Steinkohle 2014 erstmals seit langem wieder von einer Stagnation gekennzeichnet. In Deutschland ging der Steinkohlenverbrauch sogar deutlich zurueck, vor allem wegen des Rueckgangs in der Stromerzeugung. Hier hat sich die nationale Energiewende nun spuerbar und fuer die Steinkohlennutzung negativ ausgewirkt. Die politischen Weichenstellungen lassen fuer die Zukunft eine weitere erhebliche Abwaertsbewegung erwarten. Bei dem im Auslaufprozess befindlichen deutschen Steinkohlenbergbau mit noch drei aktiven Bergwerken gab es 2014 keine Stilllegung. Doch die naechste steht zum Jahresende 2015 an, und die Planungen fuer die Zeit nach dem Bergbau sind fortgefuehrt worden.

  20. Melting of polydisperse hard disks

    NARCIS (Netherlands)

    Pronk, S.; Frenkel, D.

    2004-01-01

    The melting of a polydisperse hard-disk system is investigated by Monte Carlo simulations in the semigrand canonical ensemble. This is done in the context of possible continuous melting by a dislocation-unbinding mechanism, as an extension of the two-dimensional hard-disk melting problem. We find th

  1. Hard instance generation for SAT

    OpenAIRE

    Horie, Satoshi; Watanabe, Osamu

    1998-01-01

    We propose an algorithm of generating hard instances for the Satisfying Assignment Search Problem (in short, SAT). The algorithm transforms instances of the integer factorization problem into SAT instances efficiently by using the Chinese Remainder Theorem. For example, it is possible to construct SAT instances with about 5,600 variables that is as hard as factorizing 100 bit integers.

  2. Measuring the Hardness of Minerals

    Science.gov (United States)

    Bushby, Jessica

    2005-01-01

    The author discusses Moh's hardness scale, a comparative scale for minerals, whereby the softest mineral (talc) is placed at 1 and the hardest mineral (diamond) is placed at 10, with all other minerals ordered in between, according to their hardness. Development history of the scale is outlined, as well as a description of how the scale is used…

  3. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.

  4. NANOCOMPOSITE COATINGS WITH ENHANCED HARDNESS

    Institute of Scientific and Technical Information of China (English)

    J. Musil

    2005-01-01

    The article reviews the present state of the art in the magnetron sputtering of hart and superhard nanocomposite coatings. It is shown that there are (1) two groups of hard and superhard nanocomposites: (i) nc-MN/hard phase and (ii) nc-MN/soft phase, (2) three possible origins of the enhanced hardness: (i) dislocation-dominated plastic deformation, (ii) cohesive forces between atoms and (iii) nanostructure of materials, and (3) huge differences in the microstructure of single- and two-phase films. A main attention is devoted to the formation of nanocrystalline and/or X-ray amorphous films. Such films are created in a vicinity of transitions between (i)crystalline and amorphous phases, (ii) two crystalline phases of different chemical composition or (iii) two different preferred orientations of grains of the sane material from which the coating is composed. The existence of the last transition makes it possible to explain the enhanced hardness in single-phase films. The thermal stability and oxidation resistance of hard nanocomposite films is also shortly discussed.

  5. Effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 aluminum alloys

    International Nuclear Information System (INIS)

    The present study was undertaken to investigate the effect of metallurgical parameters on the hardness and microstructural characterization of as-cast and heat-treated 356 and 319 alloys, with the aim of adjusting these parameters to produce castings of suitable hardness and Fe-intermetallic volume fractions for subsequent use in studies relating to the machinability of these alloys. By measuring the amount of Fe- and Cu-intermetallics formed and the changes in the eutectic Si particle characteristics resulting from alloying additions (Fe, Mn, Mg), Sr-modification, and heat treatment of the 356 and 319 alloys, and the corresponding hardness values, it was possible to determine which conditions or metallurgical parameters yielded the required Fe-intermetallic volume fractions of 2 and 5% and hardness levels of 85 and 115 BHN. These levels conform to the most common levels observed in the commercial application of these alloys. The 356 and 319 alloys were examined in the as-cast and heat-treated conditions, using different combinations of grain refining, Sr-modification, and alloying additions. Aging treatments were carried out at 155, 180, 200, and 220 deg. C for 4 h, followed by air cooling, as well as at 180 and 220 deg. C for 2, 4, 6, and 8 h to determine conditions under which the specified hardness levels of 85 and 115 HBN could be obtained. Hardness measurements were carried out using a Brinell hardness tester. Peak hardness was observed in the 356 and 319 alloys at different aging conditions, depending upon the Fe-intermetallic type present in the alloy and whether the alloy was modified or not. Aging at 220 deg. C revealed a hardness peak at 2 h aging time in both 356 and 319 alloys. Addition of Mg to 319 alloys produced a remarkable increase in hardness at all aging temperatures. This may be explained on the basis of the combined effect of Cu- and Mg-intermetallics in the 319 alloys, where hardening during aging occurs by the cooperative precipitation of Al

  6. Hard-soft composite magnets

    Energy Technology Data Exchange (ETDEWEB)

    Ghidini, M. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy)]. E-mail: ghidini@fis.unipr.it; Asti, G. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy); Pellicelli, R. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy); Pernechele, C. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy); Solzi, M. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy)

    2007-09-15

    A thorough micromagnetic analysis of the exchange-spring problem is reported with special emphasis on multilayers constituted by hard-soft exchange-coupled phases. The developed one-dimensional micromagnetic model leads to a complete magnetic phase diagram in terms of layer thicknesses. Both perpendicular and parallel configurations are considered. The phase diagram provides information on the type of demagnetization processes and the critical fields at which nucleation and reversal take place, depending on the intrinsic properties of the chosen soft and hard materials. The model has been applied to a variety of hard magnetic phases (e.g., FePt, CoPt, SmCo and NdFeB), coupled to different soft materials (e.g., Fe, FeCo, FeRh or permalloy) both in the form of bilayers and multilayers. The most significant results will be highlighted.

  7. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For the application of photon to industrial technologies, in particular, a hard photon technology was surveyed which uses photon beams of 0.1-200nm in wavelength. Its features such as selective atom reaction, dense inner shell excitation and spacial high resolution by quantum energy are expected to provide innovative techniques for various field such as fine machining, material synthesis and advanced inspection technology. This wavelength region has been hardly utilized for industrial fields because of poor development of suitable photon sources and optical devices. The developmental meaning, usable time and issue of a hard photon reduction lithography were surveyed as lithography in ultra-fine region below 0.1{mu}m. On hard photon analysis/evaluation technology, the industrial use of analysis, measurement and evaluation technologies by micro-beam was viewed, and optimum photon sources and optical systems were surveyed. Prediction of surface and surface layer modification by inner shell excitation, the future trend of this process and development of a vacuum ultraviolet light source were also surveyed. 383 refs., 153 figs., 17 tabs.

  8. Hard diffraction in Pythia 8

    Science.gov (United States)

    Overgaard Rasmussen, Christine

    2016-07-01

    We present an overview of the options for diffraction implemented in the general-purpose event generator Pythia 8 [1]. We review the existing model for soft diffraction and present a new model for hard diffraction. Both models use the Pomeron approach pioneered by Ingelman and Schlein, factorising the diffractive cross section into a Pomeron flux and a Pomeron PDF, with several choices for both implemented in Pythia 8. The model of hard diffraction is implemented as a part of the multiparton interactions (MPI) framework, thus introducing a dynamical gap survival probability that explicitly breaks factorisation.

  9. Hard Diffraction in Pythia 8

    CERN Document Server

    Rasmussen, Christine O

    2015-01-01

    We present an overview of the options for diffraction implemented in the general-purpose event generator Pythia 8. We review the existing model for soft diffraction and present a new model for hard diffraction. Both models use the Pomeron approach pioneered by Ingelman and Schlein, factorising the diffractive cross section into a Pomeron flux and a Pomeron PDF, with several choices for both implemented in Pythia 8. The model of hard diffraction is implemented as a part of the multiparton interactions (MPI) framework, thus introducing a dynamical gap survival probability that explicitly breaks factorisation.

  10. Evaluation of hard fossil fuel

    International Nuclear Information System (INIS)

    Because of its inexhaustible supplies hard fossil fuel will represent the pillar of the power systems of the 21st century. Only high-calorie fossil fuels have the market value and participate in the world trade. Low-calorie fossil fuels ((brown coal and lignite) are fuels spent on the spot and their value is indirectly expressed through manufactured kWh. For the purpose of determining the real value of a tonne of low-calorie coal, the criteria that help in establishing the value of a tonne of hard coal have to be corrected and thus evaluated and assessed at the market. (author)

  11. Hard sphere packings within cylinders.

    Science.gov (United States)

    Fu, Lin; Steinhardt, William; Zhao, Hao; Socolar, Joshua E S; Charbonneau, Patrick

    2016-02-23

    Arrangements of identical hard spheres confined to a cylinder with hard walls have been used to model experimental systems, such as fullerenes in nanotubes and colloidal wire assembly. Finding the densest configurations, called close packings, of hard spheres of diameter σ in a cylinder of diameter D is a purely geometric problem that grows increasingly complex as D/σ increases, and little is thus known about the regime for D > 2.873σ. In this work, we extend the identification of close packings up to D = 4.00σ by adapting Torquato-Jiao's adaptive-shrinking-cell formulation and sequential-linear-programming (SLP) technique. We identify 17 new structures, almost all of them chiral. Beyond D ≈ 2.85σ, most of the structures consist of an outer shell and an inner core that compete for being close packed. In some cases, the shell adopts its own maximum density configuration, and the stacking of core spheres within it is quasiperiodic. In other cases, an interplay between the two components is observed, which may result in simple periodic structures. In yet other cases, the very distinction between the core and shell vanishes, resulting in more exotic packing geometries, including some that are three-dimensional extensions of structures obtained from packing hard disks in a circle. PMID:26843132

  12. Stress in hard metal films

    NARCIS (Netherlands)

    Janssen, G.C.A.M.; Kamminga, J.D.

    2004-01-01

    In the absence of thermal stress, tensile stress in hard metal films is caused by grain boundary shrinkage and compressive stress is caused by ion peening. It is shown that the two contributions are additive. Moreover tensile stress generated at the grain boundaries does not relax by ion bombardment

  13. Metrics for Hard Goods Merchandising.

    Science.gov (United States)

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students interested in hard goods merchandising, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational…

  14. Kinetic theory of hard spheres

    NARCIS (Netherlands)

    Beijeren, H. van; Ernst, M.H.

    1979-01-01

    Kinetic equations for the hard-sphere system are derived by diagrammatic techniques. A linear equation is obtained for the one-particle-one particle equilibrium time correlation function and a nonlinear equation for the one-particle distribution function in nonequilibrium. Both equations are nonloca

  15. Hard processes in hadronic interactions

    International Nuclear Information System (INIS)

    Quantum chromodynamics is today accepted as the fundamental theory of strong interactions, even though most hadronic collisions lead to final states for which quantitative QCD predictions are still lacking. It therefore seems worthwhile to take stock of where we stand today and to what extent the presently available data on hard processes in hadronic collisions can be accounted for in terms of QCD. This is one reason for this work. The second reason--and in fact its original trigger--is the search for the quark-gluon plasma in high energy nuclear collisions. The hard processes to be considered here are the production of prompt photons, Drell-Yan dileptons, open charm, quarkonium states, and hard jets. For each of these, the authors discuss the present theoretical understanding, compare the resulting predictions to available data, and then show what behavior it leads to at RHIC and LHC energies. All of these processes have the structure mentioned above: they contain a hard partonic interaction, calculable perturbatively, but also the non-perturbative parton distribution within a hadron. These parton distributions, however, can be studied theoretically in terms of counting rule arguments, and they can be checked independently by measurements of the parton structure functions in deep inelastic lepton-hadron scattering. The present volume is the work of Hard Probe Collaboration, a group of theorists who are interested in the problem and were willing to dedicate a considerable amount of their time to work on it. The necessary preparation, planning and coordination of the project were carried out in two workshops of two weeks' duration each, in February 1994 at CERN in Geneva and in July 1994 at LBL in Berkeley. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  16. Hard exclusive scattering in QCD

    CERN Document Server

    Gousset, T; Gousset, Thierry; Pire, Bernard

    1995-01-01

    We review the theory of hard exclusive scattering in Quantum Chromodynamics. After recalling the classical counting rules which describe the leading scale dependence of form factors and elastic reactions at fixed angle, the pedagogical example of the pion form factor is developped in some detail in order to show explicitely what factorization means in the QCD framework. The inclusion of transverse degrees of freedom leads to the discussion of Sudakov effects which are crucial for protecting the calculation from dangerous infrared regions. The picture generalizes to many hard reactions; a strategy to extract distribution amplitudes from future data is sketched. We discuss also the particular case of hadron-hadron collisions where the independent scattering mechanism dominates asymptotically and where a different factorization formula applies. We briefly present the concepts of color transparency and nuclear filtering and critically discuss the few present data on this subject.

  17. Schwannoma of the hard palate

    OpenAIRE

    Murthy, V. Ashok; Ramaswamy, S.; Sunita, M.

    2009-01-01

    Schwannomas are benign encapsulated perineural tumors. The head and neck region is the most common site. Intraoral origin is seen in only 1% of cases, tongue being the most common site; its location in the palate is rare. We report a case of hard-palate schwannoma with bony erosion which was immunohistochemically confirmed. The tumor was excised completely intraorally. After two months of follow-up, the defect was found to be completely covered with palatal mucosa.

  18. Playing Moderately Hard to Get

    Directory of Open Access Journals (Sweden)

    Stephen Reysen

    2013-12-01

    Full Text Available In two studies, we examined the effect of different degrees of attraction reciprocation on ratings of attraction toward a potential romantic partner. Undergraduate college student participants imagined a potential romantic partner who reciprocated a low (reciprocating attraction one day a week, moderate (reciprocating attraction three days a week, high (reciprocating attraction five days a week, or unspecified degree of attraction (no mention of reciprocation. Participants then rated their degree of attraction toward the potential partner. The results of Study 1 provided only partial support for Brehm’s emotion intensity theory. However, after revising the high reciprocation condition vignette in Study 2, supporting Brehm’s emotion intensity theory, results show that a potential partners’ display of reciprocation of attraction acted as a deterrent to participants’ intensity of experienced attraction to the potential partner. The results support the notion that playing moderately hard to get elicits more intense feelings of attraction from potential suitors than playing too easy or too hard to get. Discussion of previous research examining playing hard to get is also re-examined through an emotion intensity theory theoretical lens.

  19. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... Quitting drugs is hard because addiction is a brain disease. Your brain is like a control tower that sends out ... and choices. Addiction changes the signals in your brain and makes it hard to feel OK without ...

  20. Impact of aging on radiation hardness

    International Nuclear Information System (INIS)

    Burn-in effects are used to demonstrate the potential impact of thermally activated aging effects on functional and parametric radiation hardness. These results have implications on hardness assurance testing. Techniques for characterizing aging effects are proposed

  1. Tribological characterization of selected hard coatings

    OpenAIRE

    Karlsson, Patrik

    2009-01-01

    Hard coatings are often used for protection of tool surfaces due to coating properties like low friction and high wear resistance. Even though many of the hard coatings have been tested for wear, it is important to try new wear test setups to fully understand tribological mechanisms and the potential of hard coatings. Few experiments have been performed with dual-coated systems where the sliding contact surfaces are coated with the same, or different, hard coating. The dual-coated system coul...

  2. 7 CFR 201.21 - Hard seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  3. 7 CFR 201.30 - Hard seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  4. Hard Identity and Soft Identity

    Directory of Open Access Journals (Sweden)

    Hassan Rachik

    2006-04-01

    Full Text Available Often collective identities are classified depending on their contents and rarely depending on their forms. Differentiation between soft identity and hard identity is applied to diverse collective identities: religious, political, national, tribal ones, etc. This classification is made following the principal dimensions of collective identities: type of classification (univocal and exclusive or relative and contextual, the absence or presence of conflictsof loyalty, selective or totalitarian, objective or subjective conception, among others. The different characteristics analysed contribute to outlining an increasingly frequent type of identity: the authoritarian identity.

  5. Radiation Hardness Assurance (RHA) Guideline

    Science.gov (United States)

    Campola, Michael J.

    2016-01-01

    Radiation Hardness Assurance (RHA) consists of all activities undertaken to ensure that the electronics and materials of a space system perform to their design specifications after exposure to the mission space environment. The subset of interests for NEPP and the REAG, are EEE parts. It is important to register that all of these undertakings are in a feedback loop and require constant iteration and updating throughout the mission life. More detail can be found in the reference materials on applicable test data for usage on parts.

  6. Systematic hardness studies on lithium niobate crystals

    Indian Academy of Sciences (India)

    K G Subhadra; K Kishan Rao; D B Sirdeshmukh

    2000-04-01

    In view of discrepancies in the available information on the hardness of lithium niobate, a systematic study of the hardness has been carried out. Measurements have been made on two pure lithium niobate crystals with different growth origins, and a Fe-doped sample. The problem of load variation of hardness is examined in detail. The true hardness of LiNbO3 is found to be 630 ± 30 kg/mm2. The Fe-doped crystal has a larger hardness of 750 ± 50 kg/mm2.

  7. Aespoe hard rock laboratory Sweden

    International Nuclear Information System (INIS)

    The aim of the new Aespoe hard rock laboratory is to demonstrate state of the art of technology and evaluation methods before the start of actual construction work on the planned deep repository for spent nuclear fuel. The nine country OECD/NEA project in the Stripa mine in Sweden has been an excellent example of high quality international research co-operation. In Sweden the new Aespoe hard rock laboratory will gradually take over and finalize this work. SKB very much appreciates the continued international participation in Aespoe which is of great value for the quality efficiency, and confidence in this kind of work. We have invited a number of leading experts to this first international seminar to summarize the current state of a number of key questions. The contributions show the great progress that has taken place during the years. The results show that there is a solid scientific basis for using this knowledge on site specific preparation and work on actual repositories. (au)

  8. Determining dynamical equations is hard

    CERN Document Server

    Cubitt, Toby S; Wolf, Michael M

    2010-01-01

    The behaviour of any physical system is governed by its underlying dynamical equations--the differential equations describing how the system evolves with time--and much of physics is ultimately concerned with discovering these dynamical equations and understanding their consequences. At the end of the day, any such dynamical law is identified by making measurements at different times, and computing the dynamical equation consistent with the acquired data. In this work, we show that, remarkably, this process is a provably computationally intractable problem (technically, it is NP-hard). That is, even for a moderately complex system, no matter how accurately we have specified the data, discovering its dynamical equations can take an infeasibly long time (unless P=NP). As such, we find a complexity-theoretic solution to both the quantum and the classical embedding problems; the classical version is a long-standing open problem, dating from 1937, which we finally lay to rest.

  9. A hard case for modeling

    Directory of Open Access Journals (Sweden)

    George Marsh

    2002-10-01

    Some fighter pilots alive today owe their survival to tough, low-weight helmets whose qualities have been refined as a result of biomechanical modeling. Porter and his colleagues have modeled the human head as a mechanical arrangement of a heavy ball on a rod support, as a system of soft matter contained in a hard case, as an arrangement of meso-scale sub-systems, and as a combination of material systems built up from the nano-molecular and atomic scales. An extensive modeling hierarchy (Fig. 1 is held on nothing more esoteric than a networked workstation and server architecture. Nevertheless, thanks to a process of focused simplification at each hierarchical level, it is able to predict the mechanical behavior of the human head and its constituents in reacting to impacts with considerable accuracy.

  10. Development of radiation hard scintillators

    International Nuclear Information System (INIS)

    Substantial improvements have been made in the radiation hardness of plastic scintillators. Cylinders of scintillating materials 2.2 cm in diameter and 1 cm thick have been exposed to 10 Mrads of gamma rays at a dose rate of 1 Mrad/h in a nitrogen atmosphere. One of the formulations tested showed an immediate decrease in pulse height of only 4% and has remained stable for 12 days while annealing in air. By comparison a commercial PVT scintillator showed an immediate decrease of 58% and after 43 days of annealing in air it improved to a 14% loss. The formulated sample consisted of 70 parts by weight of Dow polystyrene, 30 pbw of pentaphenyltrimethyltrisiloxane (Dow Corning DC 705 oil), 2 pbw of p-terphenyl, 0.2 pbw of tetraphenylbutadiene, and 0.5 pbw of UVASIL299LM from Ferro

  11. Hard-gapped holographic superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Pallab, E-mail: pallab@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); He Jianyang, E-mail: jyhe@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Mukherjee, Anindya, E-mail: anindya@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Shieh, H.-H., E-mail: shieh@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Perimeter Institute for Theoretical Physics, 31 Caroline Street North Waterloo, Ontario, N2L 2Y5 (Canada)

    2010-05-17

    In this work we discuss the zero temperature limit of a 'p-wave' holographic superconductor. The bulk description consists of a non-Abelian SU(2) gauge fields minimally coupled to gravity. We numerically construct the zero temperature solution which is the gravity dual of the superconducting ground state of the 'p-wave' holographic superconductors. The solution is a smooth soliton with zero horizon size and shows an emergent conformal symmetry in the IR. We found the expected superconducting behavior. Using the near horizon analysis we show that the system has a 'hard gap' for the relevant gauge field fluctuations. At zero temperature the real part of the conductivity is zero for an excitation frequency less than the gap frequency. This is in contrast with what has been observed in similar scalar-gravity-gauge systems (holographic superconductors). We also discuss the low but finite temperature behavior of our solution.

  12. A new approach to local hardness

    CERN Document Server

    Gal, T; De Proft, F; Torrent-Sucarrat, M

    2011-01-01

    The applicability of the local hardness as defined by the derivative of the chemical potential with respect to the electron density is undermined by an essential ambiguity arising from this definition. Further, the local quantity defined in this way does not integrate to the (global) hardness - in contrast with the local softness, which integrates to the softness. It has also been shown recently that with the conventional formulae, the largest values of local hardness do not necessarily correspond to the hardest regions of a molecule. Here, in an attempt to fix these drawbacks, we propose a new approach to define and evaluate the local hardness. We define a local chemical potential, utilizing the fact that the chemical potential emerges as the additive constant term in the number-conserving functional derivative of the energy density functional. Then, differentiation of this local chemical potential with respect to the number of electrons leads to a local hardness that integrates to the hardness, and possesse...

  13. Soft And Hard Skills of Social Worker

    OpenAIRE

    HANTOVÁ, Libuše

    2011-01-01

    The work deals with soft and hard skills relevant to the profession of social worker. The theoretical part at first evaluates and analyzes important soft and hard skills necessary for people working in the field of social work. Then these skills are compared. The practical part illustrates the use of soft and hard skills in practice by means of model scenes and deals with the preferences in three groups of people ? students of social work, social workers and people outside the sphere, namely ...

  14. Shock Waves in Dense Hard Disk Fluids

    OpenAIRE

    Sirmas, Nick; Tudorache, Marion; Barahona, Javier; Radulescu, Matei I.

    2011-01-01

    Media composed of colliding hard disks (2D) or hard spheres (3D) serve as good approximations for the collective hydrodynamic description of gases, liquids and granular media. In the present study, the compressible hydrodynamics and shock dynamics are studied for a two-dimensional hard-disk medium at both the continuum and discrete particle level descriptions. For the continuum description, closed form analytical expressions for the inviscid hydrodynamic description, shock Hugoniot, isentropi...

  15. Hard disks with SCSI interface

    CERN Document Server

    Denisov, O Yu

    1999-01-01

    The testing of 20 models of hard SCSI-disks is carried out: the Fujitsu MAE3091LP; the IBM DDRS-39130, DGHS-318220, DNES-318350, DRHS-36V and DRVS-18V; the Quantum Atlas VI 18.2; the Viking 11 9.1; the Seagate ST118202LW, ST118273LW, ST118273W, ST318203LW, ST318275LW, ST34520W, ST39140LW and ST39173W; and the Western Digital WDE9100-0007, WDE9100-AV0016, WDE9100-AV0030 and WDE9180-0048. All tests ran under the Windows NT 4.0 workstation operating system with Service Pack 4, under video mode with 1024*768 pixel resolution, 32- bit colour depth and V-frequency equal to 85 Hz. The detailed description and characteristics of SCSI stores are presented. Test results (ZD Winstone 99 and ZD WinBench 99 tests) are given in both table and diagram (disk transfer rate) forms. (0 refs).

  16. Development of a hard microcontroller

    International Nuclear Information System (INIS)

    The applicability of commercially available microprocessors to certain systems requiring radiation survival was assessed. A microcontroller was designed and built to perform a monitor and control function of military operational ground equipment, and demonstrated to exceed the radiation hardness goal. The preparation of the microcontroller module required hardware and software design, selection of LSI and other piece part types, development of piece part and module electrical and radiation test techniques, and the performance of radiation tests on the LSI piece parts and the completed module. The microcontroller has a 16-bit central processor unit, a 4096 word read only memory, and a 256 word read-write memory. The module has circumvention circuitry, including a PIN diode radiation detector. The processor device used was the MMI 6701 T2L Schottky bipolar 4-bit slice. Electrical exerciser circuits were developed for in-situ electrical testing of microprocessors and memories during irradiation. A test program was developed for a Terradyne J283 microcircuit tester for more complete electrical characterization of the MMI 6701 microprocessor. A simple self-test algorithm was used in the microcontroller for performance testing during irradiation. For the operational demonstration of the microcontroller a TI 960A minicomputer was used to provide the required complex inputs to the module and verify the module outputs

  17. Hardness Amplification in Proof Complexity

    CERN Document Server

    Beame, Paul; Pitassi, Toniann

    2009-01-01

    We present a general method for converting any family of unsatisfiable CNF formulas that is hard for one of the simplest proof systems, tree resolution, into formulas that require large rank in any proof system that manipulates polynomials or polynomial threshold functions of degree at most k (known as Th(k) proofs). Such systems include Lovasz-Schrijver and Cutting Planes proof systems as well as their high degree analogues. These are based on analyzing two new proof systems, denoted by T^cc(k) and R^cc(k). The proof lines of T^cc(k) are arbitrary Boolean functions, each of which can be evaluated by an efficient k-party randomized communication protocol. They include Th{k-1} proofs as a special case. R^cc(k) proofs are stronger and only require that each inference be locally checkable by an efficient k-party randomized communication protocol. Our main results are the following: (1) When k is O(loglogn), for any unsatisfiable CNF formula F requiring resolution rank r, there is a related CNF formula G=Lift_k(F...

  18. Analytical Modeling of Hard-Coating Cantilever Composite Plate considering the Material Nonlinearity of Hard Coating

    OpenAIRE

    Wei Sun; Ying Liu; Guangyu Du

    2015-01-01

    Due to the material nonlinearity of hard coating, the coated structure produces the nonlinear dynamical behaviors of variable stiffness and damping, which make the modeling of hard-coating composite structure become a challenging task. In this study, the polynomial was adopted to characterize this material nonlinearity and an analytical modeling method was developed for the hard-coating composite plate. Firstly, to relate the hard-coating material parameters obtained by test and the analytica...

  19. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,061 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  20. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,114 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  1. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,104 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  2. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,050 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  3. ERRATUM: Work smart, wear your hard hat

    CERN Multimedia

    2003-01-01

    An error appeared in the article «Work smart, wear your hard hat» published in Weekly Bulletin 27/2003, page 5. The impact which pierced a hole in the hard hat worn by Gerd Fetchenhauer was the equivalent of a box weighing 5 kg and not 50 kg.

  4. NP-hardness of hypercube 2-segmentation

    OpenAIRE

    Feige, Uriel

    2014-01-01

    The hypercube 2-segmentation problem is a certain biclustering problem that was previously claimed to be NP-hard, but for which there does not appear to be a publicly available proof of NP-hardness. This manuscript provides such a proof.

  5. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,083 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  6. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,073 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  7. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,077 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  8. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,062 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  9. Scaling, dimensional analysis, and hardness measurements

    Science.gov (United States)

    Cheng, Yang-Tse; Cheng, Che-Min; Li, Zhiyong

    2000-03-01

    Hardness is one of the frequently used concepts in tribology. For nearly one hundred years, indentation experiments have been performed to obtain the hardness of materials. Recent years have seen significant improvements in indentation equipment and a growing need to measure the mechanical properties of materials on small scales. However, questions remain, including what properties can be measured using instrumented indention techniques and what is hardness? We discuss these basic questions using dimensional analysis together with finite element calculations. We derive scaling relationships for loading and unloading curve, initial unloading slope, contact depth, and hardness. Hardness is shown to depend on elastic, as well as plastic properties of materials. The conditions for "piling-up" and "sinking-in" of surface profiles in indentation are obtained. The methods for estimating contact area are examined. The work done during indentation is also studied. A relationship between hardness, elastic modulus, and the work of indentation is revealed. This relationship offers a new method for obtaining hardness and elastic modulus. In addition, we demonstrate that stress-strain relationships may not be uniquely determined from loading/unloading curves alone using a conical or pyramidal indenter. The dependence of hardness on indenter geometry is also studied. Finally, a scaling theory for indentation in power-law creep solids using self-similar indenters is developed. A connection between creep and "indentation size effect" is established.

  10. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,071 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  11. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,096 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  12. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,117 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  13. Thermal spray coatings replace hard chrome

    International Nuclear Information System (INIS)

    Hard chrome plating provides good wear and erosion resistance, as well as good corrosion protection and fine surface finishes. Until a few years ago, it could also be applied at a reasonable cost. However, because of the many environmental and financial sanctions that have been imposed on the process over the past several years, cost has been on a consistent upward trend, and is projected to continue to escalate. Therefore, it is very important to find a coating or a process that offers the same characteristics as hard chrome plating, but without the consequent risks. This article lists the benefits and limitations of hard chrome plating, and describes the performance of two thermal spray coatings (tungsten carbide and chromium carbide) that compared favorably with hard chrome plating in a series of tests. It also lists three criteria to determine whether plasma spray or hard chrome plating should be selected

  14. Effects of Hard Water on Hair

    Science.gov (United States)

    Srinivasan, Gautham; Srinivas, Chakravarthi Rangachari; Mathew, Anil C; Duraiswami, Divakar

    2013-01-01

    Background: Hardness of water is determined by the amount of salts (calcium carbonate [CaCO3] and magnesium sulphate [MgSO4]) present in water. The hardness of the water used for washing hair may cause fragility of hair. Objective: The objective of the following study is to compare the tensile strength and elasticity of hair treated in hard water and hair treated in distilled water. Materials and Methods: 10-15 strands of hair of length 15-20 cm, lost during combing were obtained from 15 volunteers. Each sample was cut in the middle to obtain 2 sets of hair per volunteer. One set of 15 samples was immersed in hard water and the other set in distilled water for 10 min on alternate days. Procedure was repeated for 30 days. The tensile strength and elasticity of the hair treated in hard water and distilled water was determined using INSTRON universal strength tester. Results: The CaCO3 and MgSO4 content of hard water and distilled water were determined as 212.5 ppm of CaCO3 and 10 ppm of CaCO3 respectively. The tensile strength and elasticity in each sample was determined and the mean values were compared using t-test. The mean (SD) of tensile strength of hair treated in hard water was 105.28 (27.59) and in distilled water was 103.66 (20.92). No statistical significance was observed in the tensile strength, t = 0.181, P = 0.858. The mean (SD) of elasticity of hair treated in hard water was 37.06 (2.24) and in distilled water was 36.84 (4.8). No statistical significance was observed in the elasticity, t = 0.161, P = 0.874. Conclusion: The hardness of water does not interfere with the tensile strength and elasticity of hair. PMID:24574692

  15. Anonymizing Binary Tables is APX-hard

    CERN Document Server

    Bonizzoni, Paola; Dondi, Riccardo

    2007-01-01

    The problem of publishing personal data without giving up privacy is increasingly important. An interesting formalization is the $k$-anonymization, where all rows in a table are clustered in sets of at least $k$ records, and all the entries for which records in the same cluster have different values are suppressed. The problem has been shown to be NP-hard when the records values are over a ternary alphabet and $k=3$. In this paper we show that the problem is not only NP-hard, but also APX-hard, when the records values are over a binary alphabet and $k=3$.

  16. A Hybrid Combining Hard and Soft Robots

    OpenAIRE

    Stokes, Adam A.; Shepherd, Robert F.; Morin, Stephen A.; Ilievski, Filip; Whitesides, George McClelland

    2014-01-01

    This manuscript describes a hybrid robotic system combining hard and soft sub-systems. This hybrid comprises a wheeled robot (an iRobot Create©; hard) and a four-legged quadruped (soft). It is capable (using a simple, wireless control system) of rapid locomotion over flat terrain (using the wheeled hard robot), and of gripping and retrieval of an object (using the soft robot). The utility of this system is demonstrated by performing a mission requiring the capabilities of both components: ret...

  17. Radiation Hard High Performance Optoelectronic Devices Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High-performance, radiation-hard, widely-tunable integrated laser/modulator chip and large-area avalanche photodetectors (APDs) are key components of optical...

  18. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... has been rented. This feature is not available right now. Please try again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. Your brain is like a control tower ...

  19. Macroindentation hardness measurement-Modernization and applications.

    Science.gov (United States)

    Patel, Sarsvat; Sun, Changquan Calvin

    2016-06-15

    In this study, we first developed a modernized indentation technique for measuring tablet hardness. This technique is featured by rapid digital image capture, using a calibrated light microscope, and precise area-determination. We then systematically studied effects of key experimental parameters, including indentation force, speed, and holding time, on measured hardness of a very soft material, hydroxypropyl cellulose, and a very hard material, dibasic calcium phosphate, to cover a wide range of material properties. Based on the results, a holding period of 3min at the peak indentation load is recommended to minimize the effect of testing speed on H. Using this method, we show that an exponential decay function well describes the relationship between tablet hardness and porosity for seven commonly used pharmaceutical powders investigated in this work. We propose that H and H at zero porosity may be used to quantify the tablet deformability and powder plasticity, respectively. PMID:27130365

  20. A theoretical overview on single hard diffraction

    International Nuclear Information System (INIS)

    The concept of the Pomeron structure function and its application in Single Hard Diffraction at hadron colliders and in diffractive Deep Inelastic Scattering is critically reviewed. Some alternative approaches are briefly surveyed with a focus on QCD inspired models

  1. Event Driven Langevin simulations of Hard Spheres

    CERN Document Server

    Scala, Antonio

    2011-01-01

    The blossoming of interest in colloids and nano-particles has given renewed impulse to the study of hard-body systems. In particular, hard spheres have become a real test system for theories and experiments. It is therefore necessary to study the complex dynamics of such systems in presence of a solvent; disregarding hydrodynamic interactions, the simplest model is the Langevin equation. Unfortunately, standard algorithms for the numerical integration of the Langevin equation require that interactions are slowly varying during an integration timestep. This in not the case for hard-body systems, where there is no clearcut between the correlation time of the noise and the timescale of the interactions. Starting first from a splitting of the Fokker-Plank operator associated with the Langevin dynamics, and then from an approximation of the two-body Green's function, we introduce and test two new algorithms for the simulation of the Langevin dynamics of hard-spheres.

  2. Breakdown of QCD factorization in hard diffraction

    Science.gov (United States)

    Kopeliovich, B. Z.

    2016-07-01

    Factorization of short- and long-distance interactions is severely broken in hard diffractive hadronic collisions. Interaction with the spectator partons leads to an interplay between soft and hard scales, which results in a leading twist behavior of the cross section, on the contrary to the higher twist predicted by factorization. This feature is explicitly demonstrated for diffractive radiation of abelian (Drell-Yan, gauge bosons, Higgs) and non-abelian (heavy flavors) particles.

  3. Hard Discs on the Hyperbolic Plane

    OpenAIRE

    Modes, Carl D.; Kamien, Randall D.

    2007-01-01

    We examine a simple hard disc fluid with no long range interactions on the two dimensional space of constant negative Gaussian curvature, the hyperbolic plane. This geometry provides a natural mechanism by which global crystalline order is frustrated, allowing us to construct a tractable model of disordered monodisperse hard discs. We extend free area theory and the virial expansion to this regime, deriving the equation of state for the system, and compare its predictions with simulation near...

  4. Laser Ablatin of Dental Hard Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Seka, W.; Rechmann, P.; Featherstone, J.D.B.; Fried, D.

    2007-07-31

    This paper discusses ablation of dental hard tissue using pulsed lasers. It focuses particularly on the relevant tissue and laser parameters and some of the basic ablation processes that are likely to occur. The importance of interstitial water and its phase transitions is discussed in some detail along with the ablation processes that may or may not directly involve water. The interplay between tissue parameters and laser parameters in the outcome of the removal of dental hard tissue is discussed in detail.

  5. Refractive lens for hard x-rays

    International Nuclear Information System (INIS)

    The refractive lens for hard X-rays on the base of glass capillary is presented. The fabrication techniques for lens production are described. The model of refractive lens for hard X-ray is proposed. The model assume that the compound lens work similar one thin lens the complex refraction index of which is following: n=1-δ N + i β N. On the base of this model the parameters of focussed beam are calculated and the images of object are constructed

  6. Event Driven Langevin simulations of Hard Spheres

    OpenAIRE

    Scala, Antonio

    2011-01-01

    The blossoming of interest in colloids and nano-particles has given renewed impulse to the study of hard-body systems. In particular, hard spheres have become a real test system for theories and experiments. It is therefore necessary to study the complex dynamics of such systems in presence of a solvent; disregarding hydrodynamic interactions, the simplest model is the Langevin equation. Unfortunately, standard algorithms for the numerical integration of the Langevin equation require that int...

  7. Standard test methods for rockwell hardness of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 These test methods cover the determination of the Rockwell hardness and the Rockwell superficial hardness of metallic materials by the Rockwell indentation hardness principle. This standard provides the requirements for Rockwell hardness machines and the procedures for performing Rockwell hardness tests. 1.2 This standard includes additional requirements in annexes: Verification of Rockwell Hardness Testing Machines Annex A1 Rockwell Hardness Standardizing Machines Annex A2 Standardization of Rockwell Indenters Annex A3 Standardization of Rockwell Hardness Test Blocks Annex A4 Guidelines for Determining the Minimum Thickness of a Test Piece Annex A5 Hardness Value Corrections When Testing on Convex Cylindrical Surfaces Annex A6 1.3 This standard includes nonmandatory information in appendixes which relates to the Rockwell hardness test. List of ASTM Standards Giving Hardness Values Corresponding to Tensile Strength Appendix X1 Examples of Procedures for Determining Rockwell Hardness Uncertainty Appendix X...

  8. Structure, production and properties of high-melting compounds and systems (hard materials and hard metals)

    International Nuclear Information System (INIS)

    The report contains contributions by various authors to the research project on the production, structure, and physical properties of high-melting compounds and systems (hard metals and hard materials), in particular WC-, TaC-, and MoC-base materials. (GSCH)

  9. "We Can Get Everything We Want if We Try Hard": Young People, Celebrity, Hard Work

    Science.gov (United States)

    Mendick, Heather; Allen, Kim; Harvey, Laura

    2015-01-01

    Drawing on 24 group interviews on celebrity with 148 students aged 14-17 across six schools, we show that "hard work" is valued by young people in England. We argue that we should not simply celebrate this investment in hard work. While it opens up successful subjectivities to previously excluded groups, it reproduces neoliberal…

  10. Hard recharging. Metallurgical characteristics and use properties of hard recharging deposited by based cobalt alloys melting

    International Nuclear Information System (INIS)

    Hard recharging with cobalt base alloys are used in different parts of nuclear power plants. This paper presents mechanical properties, wear, thermal shock and corrosion resistances of hard coatings according to RCC-M S8000 rules, and explains relations between code recommendations and uses characteristics. (A.B.). 9 figs., 4 tabs

  11. Novel polymer derived ceramic hard materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaindl, A.; Lehner, W.; Greil, P. [Erlangen-Nuernberg Univ., Erlangen (Germany). Dept. of Mater. Sci.; Kim, D.J. [Sung Kyun Kwan Univ., Dept. of Materials Science, Suwon (Korea, Republic of)

    1997-12-31

    Manufacturing, microstructure and properties of novel ceramic hard materials derived from polymer/reactive filler mixtures were investigated. Carbide forming metal powders of Mo were used as fillers to react with the carbon bearing decomposition products of polymethylsiloxanes during pyrolysis in nitrogen atmosphere. Microcrystalline composites with the filler reaction product Mo{sub 2}C embedded in an amorphous SiOC-matrix could be formed with complex geometry due to near-netshape polymer/ceramic conversion. Depending on the filler and the pyrolysis conditions ceramic hard materials with Vickers hardness up to 10 GPa, fracture toughness of 5.1 MPa{radical}(m), a flexural strength of 330 MPa and a Youngs modulus of 280 GPa were obtained. (orig.) 8 refs.

  12. Shock Waves in Dense Hard Disk Fluids

    CERN Document Server

    Sirmas, Nick; Barahona, Javier; Radulescu, Matei I

    2011-01-01

    Media composed of colliding hard disks (2D) or hard spheres (3D) serve as good approximations for the collective hydrodynamic description of gases, liquids and granular media. In the present study, the compressible hydrodynamics and shock dynamics are studied for a two-dimensional hard-disk medium at both the continuum and discrete particle level descriptions. For the continuum description, closed form analytical expressions for the inviscid hydrodynamic description, shock Hugoniot, isentropic exponent and shock jump conditions were obtained using the Helfand equation of state. The closed-form analytical solutions permitted us to gain physical insight on the role of the material's density on its compressibility, i.e. how the medium compresses under mechanical loadings and sustains wave motion. Furthermore, the predictions were found in excellent agreement with calculations using the Event Driven Molecular Dynamic method involving 30,000 particles over the entire range of compressibility spanning the dilute id...

  13. Aespoe Hard Rock Laboratory. Annual Report 1993

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory is being constructed in preparation for the deep geological repository of spent fuel in Sweden. This Annual Report 1993 for the Aespoe Hard Rock Laboratory contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of the detailed investigation methodology. Construction of the facility and investigation of the bedrock are carried out in parallel. As of December 1993, 2760 m of the tunnel had been excavated to a depth of 370 m below the surface. An important and integral part of the work is further refinement of conceptual and numerical models for groundwater flow and radionuclide migration. Detailed plans have been prepared for several experiments to be conducted after the end of the construction work. Eight organizations from seven countries are now participating in the work at the Aespoe Hard Rock Laboratory and are contributing in different ways to the results being achieved

  14. Stackelberg Network Pricing is Hard to Approximate

    CERN Document Server

    Joret, Gwenaël

    2008-01-01

    In the Stackelberg Network Pricing problem, one has to assign tariffs to a certain subset of the arcs of a given transportation network. The aim is to maximize the amount paid by the user of the network, knowing that the user will take a shortest st-path once the tariffs are fixed. Roch, Savard, and Marcotte (Networks, Vol. 46(1), 57-67, 2005) proved that this problem is NP-hard, and gave an O(log m)-approximation algorithm, where m denote the number of arcs to be priced. In this note, we show that the problem is also APX-hard.

  15. AGN variability at hard X-rays

    OpenAIRE

    Soldi, S.; Ponti, G.; Beckmann, V.; Lubinski, P.

    2010-01-01

    We present preliminary results on the variability properties of AGN above 20 keV in order to show the potential of the INTEGRAL IBIS/ISGRI and Swift/BAT instruments for hard X-ray timing analysis of AGN. The 15-50 keV light curves of 36 AGN observed by BAT during 5 years show significantly larger variations when the blazar population is considered (average normalized excess variance = 0.25) with respect to the Seyfert one (average normalized excess variance = 0.09). The hard X-ray luminosity ...

  16. Hardness of basaltic glass-ceramics

    DEFF Research Database (Denmark)

    Jensen, Martin; Smedskjær, Morten Mattrup; Estrup, Maja; Kristjansson, Maria; Lönnroth, Nadja Teresia; Yue, Yuanzheng

    2009-01-01

    The dependence of the hardness of basaltic glass-ceramics on their degree of crystallisation has been explored by means of differential scanning calorimetry, optical microscopy, x-ray diffraction, and Vickers indentation. Different degrees of crystallisation in the basaltic glasses were achieved by...... varying the temperature of heat treatment. The predominant crystalline phase in the glass was identified as augite. It was found that the hardness of the glass phase decreased slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreased....

  17. Short hard palate in prenatal trisomy 21

    DEFF Research Database (Denmark)

    Lauridsen, H; Hansen, Birgit; Reintoft, I;

    2005-01-01

    Structured Abstract Authors - Lauridsen H, Hansen BF, Reintoft I, Keeling JW, Skovgaard LT, Kjaer I Objective - The aim of the present study was for the first time to examine on postmortal material the total midpalatal length of the hard palate and the length of its two components (the maxillary ...... our study is that the total palatal length in prenatal trisomy 21 is shorter than normal and that this is due both to a shortness of the maxillary and the palatine components of the hard palate....

  18. Mucoepidermoid carcinoma occurred in the hard palate

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun Suk; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    1994-02-15

    Authors experienced a case of intermediate grade mucoepidermoid carcinoma in 29-year-old female. The origin of this tumor might be mucus secreting cells of palatal mucous gland. The characteristic features were as follows: 1. In clinical examination, exopytic mass was observed in left hard palate and similar to pleomorphic adenoma. 2. In radiographic findings, destructive changes of left hard palate, nasal septum, nasal inferior turbinate and floor of maxillary sinus and soft tissue mass were observed. 3. Histopathologically, mucus-secreting cells, epidermoid cells and intermediate cells were observed and diagnosed as intermediate grade mucoepidermoid carcinoma.

  19. Mucoepidermoid carcinoma occurred in the hard palate

    International Nuclear Information System (INIS)

    Authors experienced a case of intermediate grade mucoepidermoid carcinoma in 29-year-old female. The origin of this tumor might be mucus secreting cells of palatal mucous gland. The characteristic features were as follows: 1. In clinical examination, exopytic mass was observed in left hard palate and similar to pleomorphic adenoma. 2. In radiographic findings, destructive changes of left hard palate, nasal septum, nasal inferior turbinate and floor of maxillary sinus and soft tissue mass were observed. 3. Histopathologically, mucus-secreting cells, epidermoid cells and intermediate cells were observed and diagnosed as intermediate grade mucoepidermoid carcinoma.

  20. Rad Hard Active Media For Calorimeters

    CERN Document Server

    Norbeck, E; Möller, A; Onel, Y

    2006-01-01

    Zero-degree calorimeters have limited space and extreme levels of radiation. A simple, low cost, radiation hard design uses tungstenmetal as the absorber and a suitable liquid as the ˇCerenkov radiator. In other applications a PPAC (Parallel Plate Avalanche Counter) operatingwith a suitable atmosphericpressure gas is an attractive active material for a calorimeter. It can be made radiation hard and has sufficient gain in the gas that no electronic components are needed near the detector. It works well even with the highest concentration of shower particles. For this pressure range, R134A (used in auto air conditioners) has many desirable features.

  1. The role of unitarity in hard diffraction

    International Nuclear Information System (INIS)

    The role of s-channel unitarity in DIS hard diffraction is discussed with special emphasize on the following issues: Froissart-Martin and s-channel unitary bounds and their implied bound for xG(x.Q2); the Q2 dependence of the hard Pomeron intercept αP(0); the t-dependence of diffractive electroproduction of vector mesons: shrinkage and diffraction dips; the determination of ψV (0,z), the vector meson wave function at the origin, from vector meson electroproduction. (author)

  2. The role of unitarity in hard diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Maor, Uri [Tel Aviv Univ. (Israel). School of Physics and Astronomy

    1997-10-01

    The role of s-channel unitarity in DIS hard diffraction is discussed with special emphasize on the following issues: Froissart-Martin and s-channel unitary bounds and their implied bound for xG(x.Q{sup 2}); the Q{sup 2} dependence of the hard Pomeron intercept {alpha}P(0); the t-dependence of diffractive electroproduction of vector mesons: shrinkage and diffraction dips; the determination of {psi}{sup V} (0,z), the vector meson wave function at the origin, from vector meson electroproduction. (author) 23 refs., 4 figs.

  3. 7 CFR 201.57 - Hard seeds.

    Science.gov (United States)

    2010-01-01

    ..., are to be counted as “hard seed.” If at the end of the germination period provided for legumes, okra... percentage of germination. For flatpea, continue the swollen seed in test for 14 days when germinating at 15..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED...

  4. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... Drugs So Hard to Quit? National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,243 4K ... Free Will - Duration: 21:12. National Institute on Drug Abuse (NIDA/NIH) 12,843 views 21:12 Anyone ...

  5. Hard photon interferometry at intermediate energies

    International Nuclear Information System (INIS)

    Two hard photons, emitted in 86Kr and 181Ta ion beams collision with 64Ni and 197Au targets, respectively, correlation function has been measured. The source of gamma emission size was determined to be 12 fm. To explain why the measured source size is much larger than size of total system (7 fm) the model with two gamma emitting sources was developed

  6. Combinatorics of hard particles on planar graphs

    International Nuclear Information System (INIS)

    We revisit the problem of hard particles on planar random tetravalent graphs in view of recent combinatorial techniques relating planar diagrams to decorated trees. We show how to recover the two-matrix model solution to this problem in this purely combinatorial language

  7. Canada,China,Closer in Hard Times

    Institute of Scientific and Technical Information of China (English)

    Guo Liqin

    2008-01-01

    @@ Facing the current global financial storm,more posSible economic and trade cooperation and promotion worldwide is being sought by nations to walk out the hard time.The 2nd Canada China Business Forum held in Beijing,on November 3,is an example to a closer tie of both countries.

  8. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... So Hard to Quit? National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,268 4K ... Drugs - Duration: 2:03. National Institute on Drug Abuse (NIDA/NIH) 92,855 views 2:03 The ...

  9. Induction surface hardening of hard coated steels

    DEFF Research Database (Denmark)

    Pantleon, Karen; Kessler, Olaf; Hoffmann, Franz; Mayr, Peter

    The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD-process is...

  10. Hard scattering in γp interactions

    International Nuclear Information System (INIS)

    We report on the investigation of the final state in interactions of quasi-real photons with protons. The data were taken with the H1 detector at the HERA ep collider. Evidence for hard interactions is seen in both single particle spectra and jet formation. The data can best be described by inclusion of resolved photon processes as predicted by QCD. (orig.)

  11. Registration of Anton Hard White Winter Wheat

    Science.gov (United States)

    ‘Anton’ (Reg. No. CV PI 651043) hard white winter wheat (Triticum aestivum L.) was developed by the USDA-ARS and the Nebraska Agricultural Experiment Station and released in December, 2007. "Anton" was selected from the cross WA691213-27/N86L177//‘Platte’. Anton primarily was released for its lo...

  12. Correlation effects in multiple hard scattering

    International Nuclear Information System (INIS)

    Correlations between the incoming partons in multiple hard scattering can affect both the event rate and kinematic distributions in the final state. In this talk, I discuss different types of correlations relevant for double parton scattering in proton-proton collisions.

  13. Rad-Hard Microcontroller for Space Applications

    Science.gov (United States)

    Habinc, Sandi; Johansson, Fredrik; Sturesson, Fredrik; Simlastik, Martin; Hjorth, Magnus; Andersson, Jan; Redant, Steven; Sijbers, Wim; Thys, Geert; Monteleone, Claudio

    2015-09-01

    This paper describes a mixed-signal LEON3FT microcontroller ASIC (Application Specific Integrated Circuit) targeting embedded control applications with hard real-time requirements. The prototype device is currently in development at Cobham Gaisler, Sweden, and IMEC, Belgium, in the activity Microcontroller for embedded space applications, initiated and funded by the European Space Agency (ESA).

  14. Dynamic impact tester of hard thin coatings

    Czech Academy of Sciences Publication Activity Database

    Grossman, Jan; Dupák, Libor; Fořt, Tomáš; Sobota, Jaroslav

    Ostrava : TANGER Ltd, 2012. ISBN 978-80-87294-29-1. [METAL 2012. International Conference on Metallurgy and Materials /21./. Brno (CZ), 23.05.2012-25.05.2012] R&D Projects: GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : impact test * wear resistance * hard coatings Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  15. Hard x-ray telescope mission

    DEFF Research Database (Denmark)

    Gorenstein, P.; Worrall, D.; Joensen, K.D.; Romaine, S.E.; Weisskopf, M.C.; Ramsey, B.D.; Bilbro, J.W.; Kroeger, R.A.; Gehrels, N.A.; Parsons, A.M.; Smither, R.K.; Christensen, Finn Erland; Citterio, O.; von Ballmoos, P.

    The Hard X-Ray Telescope was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity...

  16. On configuration spaces of hard spheres

    CERN Document Server

    Baryshnikov, Yuliy; Kahle, Matthew

    2011-01-01

    We study configuration spaces of hard spheres in a bounded region. We develop a general Morse-theoretic framework, and show that mechanically balanced configurations play the role of critical points. As an application, we find the precise threshold radius for a configuration space to be homotopy equivalent to the configuration space of points.

  17. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... So Hard to Quit? National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 4,301 4K ... Will - Duration: 21:12. National Institute on Drug Abuse (NIDA/NIH) 13,193 views 21:12 Anyone ...

  18. Second virial coefficients of dipolar hard spheres

    NARCIS (Netherlands)

    Philipse, A.P.; Kuipers, B.W.M.

    2010-01-01

    An asymptotic formula is reported for the second virial coefficient B2 of a dipolar hard-sphere (DHS) fluid, in zero external field, for strongly coupled dipolar interactions. This simple formula, together with the one for the weak-coupling B2, provides an accurate prediction of the second virial co

  19. Hard-core square-well fermions

    International Nuclear Information System (INIS)

    Based on the well-known low-density expansion for the ground-state energy per particle of a many-fermion system interacting pairwise via a central potential we develop a perturbation scheme in which the zero-order state is that of the purely-repulsive-spheres fluid. For the hard-core plus square-well pair-interaction case we have deduced, for two-species fermion matter, perturbation formulas up to sixth order in the attractive coupling parameter. We explicitly report results up to fourth order here. Pade-approximant analyses in the density are carried out in each order with the intent of providing the basis necessary for extensive equation-of-state calculations of various many-fermion systems. In particular, for zero order (the fermion hard-sphere fluid) we predict an uncertainty-principle divergence in the energy, and hence pressure, corresponding to the random close packing of spheres, at a density of about 0.5 times the recently obtained value for boson hard spheres and about 0.2 times the well-known empirical value for classical hard spheres

  20. Why Is It So Hard to Quit?

    Science.gov (United States)

    ... by State SELECT YOUR LANGUAGE Español (Spanish) 简体中文 (Traditional Chinese) 繁体中文 (Simplified Chinese) Tiếng Việt (Vietnamese) Healthy ... to quit? It’s hard to tackle the physical addiction to nicotine . Cigarettes contain nicotine, a highly addictive ...

  1. Correlation effects in multiple hard scattering

    CERN Document Server

    Diehl, Markus

    2013-01-01

    Correlations between the incoming partons in multiple hard scattering can affect both the event rate and kinematic distributions in the final state. In this talk, I discuss different types of correlations relevant for double parton scattering in proton-proton collisions.

  2. Stability of Hardly Reshaping Berm Breakwaters

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Van der Meer, Jentsje W.; Burcharth, Hans F.;

    2012-01-01

    The present paper deals with stability of berm breakwaters designed to be hardly or sometimes partly reshaping. Burcharth (2008, 2011) showed by comparison to the performance of a prototype berm breakwater that the Van der Meer formulae for stability of conventional rock armour including low cres...

  3. Hard nanocomposite coatings. Present status and trends

    Czech Academy of Sciences Publication Activity Database

    Musil, Jindřich; Baroch, P.; Zeman, P.

    Kerala: Research Signpost, 2008 - (Wei, R.), s. 1-34 ISBN 978-81-308-0257-2 R&D Projects: GA AV ČR KAN400100653 Institutional research plan: CEZ:AV0Z10100520 Keywords : nanocomposite coatings * enhanced hardness * thermal stability Subject RIV: BM - Solid Matter Physics ; Magnetism http://www.ressign.com/UserBookDetail.aspx?bkid=708&catid=174#

  4. Decision-theoretic troubleshooting: Hardness of approximation

    Czech Academy of Sciences Publication Activity Database

    Lín, Václav

    2014-01-01

    Roč. 55, č. 4 (2014), s. 977-988. ISSN 0888-613X R&D Projects: GA ČR GA13-20012S Institutional support: RVO:67985556 Keywords : Decision-theoretic troubleshooting * Hardness of approximation * NP-completeness Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.451, year: 2014

  5. "Work smart, wear your hard hat"

    CERN Multimedia

    2003-01-01

    Falling objects and collisions are frequent occurrences in work sites and hazardous areas. Hard hats can help prevent many types of accident and can even save lives. Just imagine an 800 g spanner falling from a 13 m high scaffold onto the head of someone standing below - a nightmare scenario! The impact to the head is equivalent to that of a 5 kg weight falling from 2 metres. That is just what happened to Gerd Fetchenhauer when he was working on the UA1 experiment. Fortunately, he was wearing a hard hat at the time. "That hat saved my life," he explains. "It punched a hole right through the hat and I was a bit dazed for a couple of hours but otherwise I was OK." Since that day, Gerd Fetchenhauer, now working on CMS, is never seen on a work site without his hard hat on. Work sites have proliferated at CERN with the construction of the LHC and its detectors, and the wearing of hard hats is compulsory (not to mention life-saving). In the underground caverns and experiment halls, where gantry cranes and other h...

  6. Training a Single Sigmoidal Neuron is Hard

    Czech Academy of Sciences Publication Activity Database

    Šíma, Jiří

    2002-01-01

    Roč. 14, č. 11 (2002), s. 2709-2729. ISSN 0899-7667 R&D Projects: GA MŠk LN00A056 Keywords : sigmoidal neuron * loading problem * NP-hardness Subject RIV: BA - General Mathematics Impact factor: 2.313, year: 2002

  7. Classic and Hard-Boiled Detective Fiction.

    Science.gov (United States)

    Reilly, John M.

    Through an analysis of several stories, this paper defines the similarities and differences between classic and hard-boiled detective fiction. The characters and plots of three stories are discussed: "The Red House" by A. A. Milne; "I, The Jury" by Mickey Spillane; and "League of Frightened Men" by Rex Stout. The classic detective story is defined…

  8. Hard Distraction and Deep Inelastic Scattering

    International Nuclear Information System (INIS)

    Since the advent of hard-collision physics, the study of diffractive processes- 'shadow physics' - has been less prominent than before. However, there is now a renewed interest in the subject, especially in that aspect which synthesizes the short-distance, hard-collision phenomena with the classical physics of large rapidity-gaps. This is especially stimulated by the recent data on deep-inelastic scattering from HERA, as well as the theoretical work which relates to it. The word 'diffraction' is sometimes used by high-energy physicists in a loose way. So I here begin by defining what I mean by the term: A diffractive process occurs if and only if there is a large rapidity gap in the produced-particle phase space which is not exponentially suppressed. Here a rapidity gap means essentially no hadrons produced into the rapidity gap (which operates in the 'lego' phase-space of pseudo-rapidity and azimuthal angle). And non-exponential suppression implies that the cross-section for creating a gap with width Δη does not have a power-law decrease with increasing sub energy Δη, but behaves at most like some power of pseudorapidity Δη∼ logs. The term 'hard diffraction' shall simply refer to those diffractive processes which have jets in the final-state phase-space. We may also distinguish, if desired, two subclasses, as suggested by Ingelman i) Diffractive hard processes have jets on only one side of the rapidity gap. ii) Hard diffractive processes have jets on both sides of the rapidity gap

  9. Hard rectangles near curved hard walls: tuning the sign of the Tolman length

    CERN Document Server

    Sitta, Christoph E; Wittkowski, Raphael; Löwen, Hartmut

    2016-01-01

    Combining analytic calculations, computer simulations, and classical density functional theory we determine the interfacial tension of orientable two-dimensional hard rectangles near a curved hard wall. Both a circular cavity holding the particles and a hard circular obstacle surrounded by particles are considered. We focus on moderate bulk densities (corresponding to area fractions up to 50 percent) where the bulk phase is isotropic and vary the aspect ratio of the rectangles and the curvature of the wall. The Tolman length, which gives the leading curvature correction of the interfacial tension, is found to change sign at a finite density, which can be tuned via the aspect ratio of the rectangles.

  10. Hard spheres at a planar hard wall: Simulations and density functional theory

    OpenAIRE

    Davidchack, R. L.; Laird, B. B.; Roth, R.

    2016-01-01

    Hard spheres are a central and important model reference system for both homogeneous and inhomogeneous fluid systems. In this paper we present new high-precision molecular-dynamics computer simulations for a hard sphere fluid at a planar hard wall. For this system we present benchmark data for the density profile $\\rho(z)$ at various bulk densities, the wall surface free energy $\\gamma$, the excess adsorption $\\Gamma$, and the excess volume $v_{ex}$, which is closely related to $\\Gamma$. We c...

  11. Hardness of materials: studies at levels from atoms to crystals

    Institute of Scientific and Technical Information of China (English)

    LI KeYan; XUE DongFeng

    2009-01-01

    Based on the electron-holding energy per unit volume, we extend the concept of hardness to atomic stiffness, ionic stiffness and bond hardness, investigating the nature of material hardness at these three levels. We find that the stiffness of isolated atoms or ions has no direct connection with the hardness of materials, whereas material hardness is directly related to bond hardness, which is es-sentially determined by the electron-holding energy of its constituent chemical bonds per unit volume. We establish a model for identifying the hardness of materials on the basis of bond hardness. This work offers a deeper understanding of the nature of material hardness at the atomic level, and provides a practical guide in the search for new superhard materials.

  12. The unconstrained local hardness: an intriguing quantity, beset by problems.

    Science.gov (United States)

    Cuevas-Saavedra, Rogelio; Rabi, Nataly; Ayers, Paul W

    2011-11-21

    Developing a mathematical approach to the local hard/soft acid/base principle requires an unambiguous definition for the local hardness. One such quantity, which has aroused significant interest in recent years, is the unconstrained local hardness. Key identities are derived for the unconstrained local hardness, δμ/δρ(r). Several identities are presented which allow one to determine the unconstrained local hardness either explicitly using the hardness kernel and the inverse-linear response function, or implicitly by solving a system of linear equations. One result of this analysis is that the problem of determining the unconstrained local hardness is infinitely ill-conditioned because arbitrarily small changes in electron density can cause enormous changes in the chemical potential. This is manifest in the exponential divergence of the unconstrained local hardness as one moves away from the system. This suggests that one should be very careful when using the unconstrained local hardness for chemical interpretation. PMID:21984043

  13. Addition to the methodology of research into permanent teeth hardness

    Directory of Open Access Journals (Sweden)

    Gnjato Sanja

    2010-01-01

    Full Text Available This paper examines permanent teeth hardness (microhardness using the Vickers method. An original methodology was developed and adopted for preparing the experimental material, i.e. the cross sections into four characteristic locations on the tooth: corona dentis, cervix dentis, pars medialis radicis dentis and apex radicis dentis. A new 'hardness profile' was introduced, which connects hardness and location along the cross section of the tooth. Hardness was measured 664 times on experimental cross sections with total a average hardness of 73.17 HV according to Vickers and a standard deviation of 55.68 HV. The derived descriptive statistical indicators of tooth hardness were calculated for equivalent cross sections, individual teeth, teeth groups and tooth localizations. Two algorithms were developed for determining the rank of tooth hardness - one for estimating the rank of arithmetic mean of the hardness of the cross sections of the teeth, and the other for estimating the rank of hardness for individual teeth. .

  14. Microbiological quality of soft, semi-hard and hard cheeses during the shelf-life

    Directory of Open Access Journals (Sweden)

    Josip Vrdoljak

    2016-03-01

    Full Text Available Cheeses as ready-to-eat food should be considered as a potential source of foodborne pathogens, primarily Listeria monocytogenes. The aim of present study was to determine the microbiological quality of soft, semi-hard and hard cheeses during the shelf-life, with particular reference to L. monocytogenes. Five types of cheeses were sampled at different timepoints during the cold storage and analyzed for presence of Salmonella and L. monocytogenes, as well as lactic acid bacteria, Escherichia coli, coagulase-positive staphylococci, yeasts, molds, sulfite-reducing clostridia and L. monocytogenes counts. Water activity, pH and NaCl content were monitored in order to evaluate the possibility of L. monocytogenes growth. Challenge test for L. monocytogenes was performed in soft whey cheese, to determine the growth potential of pathogen during the shelf-life of product. All analyzed cheeses were compliant with microbiological criteria during the shelf-life. In soft cheeses, lactic acid bacteria increased in the course of the shelf-life period (1.2-2.6 log increase, while in semi-hard and hard cheeses it decreased (1.6 and 5.2 log decrease, respectively. Soft cheeses support the growth of L. monocytogenes according to determined pH values (5.8-6.5, water activity (0.99-0.94, and NaCl content (0.3-1.2%. Challenge test showed that L. monocytogenes growth potential in selected soft cheese was 0.43 log10 cfu/g during 8 days at 4°C. Water activity in semi-hard and hard cheeses was a limiting factor for Listeria growth during the shelf-life. Soft, semi-hard and hard cheeses were microbiologically stable during their defined shelf-life. Good manufacturing and hygienic practices must be strictly followed in the production of soft cheeses as Listeria-supporting food and be focused on preventing (recontamination.

  15. Book Review: Trade unions in western Europe: hard times, hard choices

    OpenAIRE

    Manzella, Pietro

    2013-01-01

    "Trade Unions in Western Europe: Hard Times, Hard Choices." Rebecca Gumbrell-McCormick and Richard Hyman. Oxford University Press. October 2013. --- In this book the authors attempt to provide an account of how trade unionism has evolved in ten west European countries, the main recent challenges that unions have faced, and their responses. This work will certainly make a fundamental contribution to the debate about the future role and functions of unions as the authors provide key insights i...

  16. Hard-on-hard lubrication in the artificial hip under dynamic loading conditions.

    Directory of Open Access Journals (Sweden)

    Robert Sonntag

    Full Text Available The tribological performance of an artificial hip joint has a particularly strong influence on its success. The principle causes for failure are adverse short- and long-term reactions to wear debris and high frictional torque in the case of poor lubrication that may cause loosening of the implant. Therefore, using experimental and theoretical approaches models have been developed to evaluate lubrication under standardized conditions. A steady-state numerical model has been extended with dynamic experimental data for hard-on-hard bearings used in total hip replacements to verify the tribological relevance of the ISO 14242-1 gait cycle in comparison to experimental data from the Orthoload database and instrumented gait analysis for three additional loading conditions: normal walking, climbing stairs and descending stairs. Ceramic-on-ceramic bearing partners show superior lubrication potential compared to hard-on-hard bearings that work with at least one articulating metal component. Lubrication regimes during the investigated activities are shown to strongly depend on the kinematics and loading conditions. The outcome from the ISO gait is not fully confirmed by the normal walking data and more challenging conditions show evidence of inferior lubrication. These findings may help to explain the differences between the in vitro predictions using the ISO gait cycle and the clinical outcome of some hard-on-hard bearings, e.g., using metal-on-metal.

  17. High hardness of alloyed ferrite after nitriding

    International Nuclear Information System (INIS)

    Detailed layer-by layer structure and phase analyses of the diffusion layer of nitrided binary alloys of iron with aluminium, chromium, vanadium and titanium have been carried out by means of a complex technique. Transition d-metals (chromium, vanadium and titanium) raise to a greater degree the solubility of nitrogen in the α solid solution, sharply increases the hardness of ferrite and decrease the depth of the layer. Nitrided binary alloys of iron with chromium, vanadium and titanium are strengthened through precipitation from the nitrogen-saturated α-solid solution of nitrides of alloying elements TiN, VN and CrN of a structure B1. A maximum hardness of ferrite alloyed by chromium, vanadium and titanium is observed after nitriding at 550 deg C when the precipitated special nitrides are fully coherent with the α matrix

  18. Locating phase transitions in computationally hard problems

    Indian Academy of Sciences (India)

    B Ashok; T K Patra

    2010-09-01

    We discuss how phase-transitions may be detected in computationally hard problems in the context of anytime algorithms. Treating the computational time, value and utility functions involved in the search results in analogy with quantities in statistical physics, we indicate how the onset of a computationally hard regime can be detected and the transit to higher quality solutions be quantified by an appropriate response function. The existence of a dynamical critical exponent is shown, enabling one to predict the onset of critical slowing down, rather than finding it after the event, in the specific case of a travelling salesman problem (TSP). This can be used as a means of improving efficiency and speed in searches, and avoiding needless computations.

  19. Laser ablated hard coating for microtools

    Science.gov (United States)

    McLean, II, William; Balooch, Mehdi; Siekhaus, Wigbert J.

    1998-05-05

    Wear-resistant coatings composed of laser ablated hard carbon films, are deposited by pulsed laser ablation using visible light, on instruments such as microscope tips and micro-surgical tools. Hard carbon, known as diamond-like carbon (DLC), films produced by pulsed laser ablation using visible light enhances the abrasion resistance, wear characteristics, and lifetimes of small tools or instruments, such as small, sharp silicon tips used in atomic probe microscopy without significantly affecting the sharpness or size of these devices. For example, a 10-20 nm layer of diamond-like carbon on a standard silicon atomic force microscope (AFM) tip, enables the useful operating life of the tip to be increased by at least twofold. Moreover, the low inherent friction coefficient of the DLC coating leads to higher resolution for AFM tips operating in the contact mode.

  20. Hard exclusive reactions and generalized parton distributions

    Directory of Open Access Journals (Sweden)

    Hayrapetyan Avetik

    2015-01-01

    Full Text Available The recently developed formalism of Generalized Parton Distributions (GPDs allows connecting the experimental information of hard exclusive reactions to the spin contribution and even to the angular momentum contribution of quarks in the nucleon. By selecting different quantum numbers of the final state in exclusive productions, different GPDs can be addressed separately. The HERMES experiment at the HERA ring at DESY (Hamburg made pioneering contributions and first constraints to Generalized Parton Distributions (GPDs, using hard exclusive vector meson production (EVMP and Deeply Virtual Compton Scattering (DVCS. Using a novel recoil detector, HERMES managed to measure DVCS and EVMP free of any significant background. Selected results are highlighted and discussed in this paper.

  1. Fixed target electroweak and hard scattering physics

    International Nuclear Information System (INIS)

    The possibilities for future physics and experiments involving weak and electromagnetic interactions, neutrino oscillations, general hard scattering and experiments involving nuclear targets were explored. The studies were limited to the physics accessible using fixed target experimentation. While some of the avenues explored turn out to be relatively unrewarding in the light of competition elsewhere in the world, there are a number of positive conclusions reached about experimentation in the energy range available to the Main Injector and Tevatron. Some of the experiments would benefit from the increased intensity available from the Tevatron utilizing the Main Injector, while some require this increase. Finally, some of the experiments would use the Main Injector low energy, high intensity extracted beams directly. A program of electroweak and hard scattering experiments at fixed target energies retains the potential for important contributions to physics. The key to major parts of this program would appear to be the existence of the Main Injector. 115 refs, 17 figs

  2. Aespoe hard rock laboratory. Annual report 1992

    International Nuclear Information System (INIS)

    The Aespoe hard rock laboratory is being constructed in preparation for the deep geological repository of spent fuel in Sweden. This Annual report 1992 for the Aespoe hard rock laboratory contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of the detailed investigation methodology. Construction of the facility and investigation of the bedrock are being carried out in parallel. December 1992 1925 m of the tunnel has been excavated to a depth of 255 m below surface. An important and integrated part of the work is further refinement of conceptual and numerical models for groundwater flow and radionuclide migration. This work is carried out in cooperation with seven organizations from six countries that participate in the project. (25 refs.)

  3. Soft Contributions to Hard Pion Photoproduction

    CERN Document Server

    Afanasiev, A V; Wahlquist, C; Afanasev, Andrei; Carlson, Carl E.; Wahlquist, Christian

    2000-01-01

    Hard, or high transverse momentum, pion photoproduction can be a tool for probing the parton structure of the beam and target. We estimate the soft contributions to this process, with an eye toward delineating the region where perturbatively calculable processes dominate. Our soft process estimate is based on vector meson dominance and data based parameterizations of semiexclusive hadronic cross sections. We find that soft processes dominate in single pion photoproduction somewhat past 2 GeV transverse momentum at a few times 10 GeV incoming energy. The recent polarization asymmetry data is consistent with the perturbative asymmetry being diluted by polarization insensitive soft processes. Determining the polarized gluon distribution using hard pion photoproduction appears feasible with a few hundred GeV incoming energy (in the target rest frame).

  4. Magnetic hyperthermia with hard-magnetic nanoparticles

    International Nuclear Information System (INIS)

    Recent clinical trials of magnetic hyperthermia have proved, and even hardened, the Ankinson-Brezovich restriction as upon magnetic field conditions applicable to any site of human body. Subject to this restriction, which is harshly violated in numerous laboratory and small animal studies, magnetic hyperthermia can relay on rather moderate heat source, so that optimization of the whole hyperthermia system remains, after all, the basic problem predetermining its clinical perspectives. We present short account of our complex (theoretical, laboratory and small animal) studies to demonstrate that such perspectives should be related with the hyperthermia system based on hard-magnetic (Stoner–Wohlfarth type) nanoparticles and strong low-frequency fields rather than with superparamagnetic (Brownian or Neél) nanoparticles and weak high-frequency fields. This conclusion is backed by an analytical evaluation of the maximum absorption rates possible under the field restriction in the ideal hard-magnetic (Stoner–Wohlarth) and the ideal superparamagnetic (single relaxation time) systems, by theoretical and experimental studies of the dynamic magnetic hysteresis in suspensions of movable hard-magnetic particles, by producing nanoparticles with adjusted coercivity and suspensions of such particles capable of effective energy absorption and intratumoral penetration, and finally, by successful treatment of a mice model tumor under field conditions acceptable for whole human body. - Highlights: • Hard-magnetic nanoparticles are shown superior for hyperthetmia to superparamagnetic. • Optimal system parameters are found from magnetic reversal model in movable particle. • Penetrating suspension of HM particles with aggregation-independent SAR is developed. • For the first time, mice with tumors are healed in AC field acceptable for human body

  5. Soft Contributions to Hard Pion Photoproduction

    OpenAIRE

    Afanasev, Andrei; Carlson, Carl E.; Wahlquist, Christian

    1999-01-01

    Hard, or high transverse momentum, pion photoproduction can be a tool for probing the parton structure of the beam and target. We estimate the soft contributions to this process, with an eye toward delineating the region where perturbatively calculable processes dominate. Our soft process estimate is based on vector meson dominance and data based parameterizations of semiexclusive hadronic cross sections. We find that soft processes dominate in single pion photoproduction somewhat past 2 GeV ...

  6. Crystallization in Glassy Suspensions of Hard Ellipsoids

    OpenAIRE

    Dorosz, Sven; Schilling, Tanja

    2013-01-01

    We have carried out computer simulations of overcompressed suspensions of hard monodisperse ellipsoids and observed their crystallization dynamics. The system was compressed very rapidly in order to reach the regime of slow, glass-like dynamics. We find that, although particle dynamics become sub-diffusive and the intermediate scattering function clearly develops a shoulder, crystallization proceeds via the usual scenario: nucleation and growth for small supersaturations, spinodal decompositi...

  7. Mining technology development for hard rock excavation

    International Nuclear Information System (INIS)

    A research facility has been established in the granitic gneiss of the CSM Experimental Mine at Idaho Springs, Colorado, for the purpose of evaluating/developing mining, geologic and geotechnical procedures appropriate for use in establishing nuclear waste repositories in hard rock. An experimental room has been excavated using careful blasting procedures. The extent and magnitude of blast damage is being evaluated. Structural geology is being mapped to assess continuity

  8. HERMES Measurements of Hard-Exclusive Processes

    Energy Technology Data Exchange (ETDEWEB)

    Marianski, Bohdan

    2008-11-15

    Three HERMES measurements of hard-exclusive processes usefull for testing Generalized Parton Distributions (GPDs) are described. Firstly, Spin Density Matrix Elements (SDMEs) are determined from exclusive diffractive {rho}{sup 0} and {phi} electroproduction in the HERMES experiment at 27.5 GeV beam energy. Then, Transverse Target Spin Asymmetry (TTSA) in exclusive {rho}{sup 0} production and in Deeply Virtual Compton Scattering (DVCS) process on a transversally polarized hydrogen target is determined.

  9. Hard Realtime Rapid Prototyping Development Platform

    OpenAIRE

    Rosenquist, Christer

    2003-01-01

    Matlab Simulink is a commonly used tool in the design process of control systems. To further take advantage of the Matlab Simulink models it is desirable to translate them for realtime use together with the possibility to read/write physical signals. Real-Time Workshop is an extension to Simulink that automatically generates code from a model to a variety of target platforms. RTAI and RTLinux are hard realtime operating systems, making use of Linux. To make automatically generated code run ...

  10. Hard photon production by inverse Compton scattering

    International Nuclear Information System (INIS)

    The controlled production of hard photons (X and γ-rays) is of relevance in many medical, industrial and science applications. In this work an alternative method for producing both X and γ-rays via Inverse Compton Scattering with both electron and proton beams is discussed. We present results for the cross section for this process with non static electron and protons. The results are evaluated for a particular energy interval, and an experimental design is proposed.

  11. Soft and hard nanostructured magnetic materials

    International Nuclear Information System (INIS)

    Tailoring of soft and hard magnetic materials can be performed by nanocrystallisation. Random anisotropy and intergranular exchange govern the macroscopic properties of nanocrystalline ferromagnets. The nature and topology of the intergranular region, matrix or grain boundaries, determine the degree of intergranular coupling. Important information about magnetic and topological properties of grain boundaries can be inferred from Moessbauer spectroscopy. The state of the art of those tailored materials is reviewed paying special attention to the correlation between nanostructure and macroscopic properties

  12. Classic Nintendo Games are (Computationally) Hard

    OpenAIRE

    Aloupis, Greg; Demaine, Erik D.; Guo, Alan; Viglietta, Giovanni

    2012-01-01

    We prove NP-hardness results for five of Nintendo's largest video game franchises: Mario, Donkey Kong, Legend of Zelda, Metroid, and Pokemon. Our results apply to generalized versions of Super Mario Bros. 1-3, The Lost Levels, and Super Mario World; Donkey Kong Country 1-3; all Legend of Zelda games; all Metroid games; and all Pokemon role-playing games. In addition, we prove PSPACE-completeness of the Donkey Kong Country games and several Legend of Zelda games.

  13. Hard Coating on Steel – A Review

    OpenAIRE

    Ms. HiteshriJadhav; Mr.Parthiv Trivedi

    2014-01-01

    Now a days various coating techniques are being used in different fields for a large number of applications. This paper consists of different effects and its respective changes on the steel substrate material coated by High Velocity Oxy Fuel (HVOF) coating. It helps enhance the properties such as micro structure, abrasive wear, wear resistance etc. and various techniques such as SEM, XRD, Pin-On-Disc etc. are used to check and analysis these properties. On hard coating steel the material may ...

  14. Blazar microvariability at hard X-rays

    OpenAIRE

    Foschini, L.; Gliozzi, M.; Pian, E.; Tagliaferri, G.; Tavecchio, F.; Bianchin, V.; L. Maraschi(INAF National Institute for Astrophysics, I-00136 Rome, Italy); Sambruna, R. M.; Di Cocco, G.; Ghisellini, G.; Malaguti, G.; Tosti, G.; Treves, A.

    2007-01-01

    Blazars are known to display strong and erratic variability at almost all the wavelengths of electromagnetic spectrum. Presently, variability studies at high-energies (hard X-rays, gamma-rays) are hampered by low sensitivity of the instruments. Nevertheless, the latest generation of satellites (INTEGRAL, Swift) have given suggestions not yet fully confirmed of variability on intraday timescales. Some specific cases recently observed are presented and physical implications are discussed (e.g. ...

  15. Certifying the restricted isometry property is hard

    CERN Document Server

    Bandeira, Afonso S; Mixon, Dustin G; Sawin, William F

    2012-01-01

    This paper is concerned with an important matrix condition in compressed sensing known as the restricted isometry property (RIP). We demonstrate that testing whether a matrix satisfies RIP is hard for NP under randomized polynomial-time reductions. Our reduction is from the NP-complete clique decision problem, and it uses ideas from matroid theory. As a consequence of our result, it is impossible to efficiently test for RIP provided NP \

  16. Magnetic hyperthermia with hard-magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kashevsky, Bronislav E., E-mail: bekas@itmo.by [A.V Luikov Heat and Mass Transfer Institute, Belarus Academy of Sciences, P. Brovka str. 15, Minsk 220072 (Belarus); Kashevsky, Sergey B.; Korenkov, Victor S. [A.V Luikov Heat and Mass Transfer Institute, Belarus Academy of Sciences, P. Brovka str. 15, Minsk 220072 (Belarus); Istomin, Yuri P. [N. N. Alexandrov National Cancer Center of Belarus, Lesnoy-2, Minsk 223040 (Belarus); Terpinskaya, Tatyana I.; Ulashchik, Vladimir S. [Institute of Physiology, Belarus Academy of Sciences, Akademicheskaya str. 28, Minsk 220072 (Belarus)

    2015-04-15

    Recent clinical trials of magnetic hyperthermia have proved, and even hardened, the Ankinson-Brezovich restriction as upon magnetic field conditions applicable to any site of human body. Subject to this restriction, which is harshly violated in numerous laboratory and small animal studies, magnetic hyperthermia can relay on rather moderate heat source, so that optimization of the whole hyperthermia system remains, after all, the basic problem predetermining its clinical perspectives. We present short account of our complex (theoretical, laboratory and small animal) studies to demonstrate that such perspectives should be related with the hyperthermia system based on hard-magnetic (Stoner–Wohlfarth type) nanoparticles and strong low-frequency fields rather than with superparamagnetic (Brownian or Neél) nanoparticles and weak high-frequency fields. This conclusion is backed by an analytical evaluation of the maximum absorption rates possible under the field restriction in the ideal hard-magnetic (Stoner–Wohlarth) and the ideal superparamagnetic (single relaxation time) systems, by theoretical and experimental studies of the dynamic magnetic hysteresis in suspensions of movable hard-magnetic particles, by producing nanoparticles with adjusted coercivity and suspensions of such particles capable of effective energy absorption and intratumoral penetration, and finally, by successful treatment of a mice model tumor under field conditions acceptable for whole human body. - Highlights: • Hard-magnetic nanoparticles are shown superior for hyperthetmia to superparamagnetic. • Optimal system parameters are found from magnetic reversal model in movable particle. • Penetrating suspension of HM particles with aggregation-independent SAR is developed. • For the first time, mice with tumors are healed in AC field acceptable for human body.

  17. Pleomorphic adenoma of the hard palate

    Directory of Open Access Journals (Sweden)

    Kaur S

    2003-03-01

    Full Text Available Pleomorphic adenoma is a benign tumor of the salivary glands that has elements of both epithelial and mesenchymal tissues. The tumor most commonly arises in the parotid or submandibular glands. Infrequently, it may arise from the minor salivary glands and present as an intraoral mass over the palate or lip. We report a patient with pleomorphic adenoma over the hard palate, which resembled common intraoral diseases like condyloma acuminata, oral papilloma and squamous cell carcinoma.

  18. WALNUT: NOT A HARD NUT TO CRACK

    OpenAIRE

    Khanna Deepa; Parle Milind

    2011-01-01

    Walnuts grow on large trees, known for their beauty, timber and tasty edible nuts. There are many varieties of walnuts that vary in hardiness, nut size and thickness of the nut shell. When it comes to their health benefits, Walnuts definitely are not hard nuts to crack. They contain free radical scavenging compounds like ellagic acid, juglone and certain phytosterols that support the immune system and appear to have anti-cancer properties. Walnuts have higher contents of polyunsaturated fatty...

  19. Classic Nintendo Games Are (Computationally) Hard

    OpenAIRE

    Aloupis, Greg; Demaine, Erik D.; Guo, Alan; Viglietta, Giovanni

    2014-01-01

    We prove NP-hardness results for five of Nintendo’s largest video game franchises: Mario, Donkey Kong, Legend of Zelda, Metroid, and Pokemon. Our results apply to generalized versions of Super Mario Bros. 1, 3, Lost Levels, and Super Mario World; Donkey Kong Country 1–3; all Legend of Zelda games; all Metroid games; and all Pokemon role-playing games. In addition, we prove PSPACE-completeness of the Donkey Kong Country games and several Legend of Zelda games.

  20. AGN variability at hard X-rays

    CERN Document Server

    Soldi, S; Beckmann, V; Lubinski, P

    2010-01-01

    We present preliminary results on the variability properties of AGN above 20 keV in order to show the potential of the INTEGRAL IBIS/ISGRI and Swift/BAT instruments for hard X-ray timing analysis of AGN. The 15-50 keV light curves of 36 AGN observed by BAT during 5 years show significantly larger variations when the blazar population is considered (average normalized excess variance = 0.25) with respect to the Seyfert one (average normalized excess variance = 0.09). The hard X-ray luminosity is found to be anti-correlated to the variability amplitude in Seyfert galaxies and correlated to the black hole mass, confirming previous findings obtained with different AGN hard X-ray samples. We also present results on the Seyfert 1 galaxy IC 4329A, as an example of spectral variability study with INTEGRAL/ISGRI data. The position of the high-energy cut-off of this source is found to have varied during the INTEGRAL observations, pointing to a change of temperature of the Comptonising medium. For several bright Seyfert...

  1. Hardness variability in commercial and hardened technologies

    International Nuclear Information System (INIS)

    Over the past 10 years, there have been a number of advances in methods to assess and assure the radiation hardness of microelectronics in military and space applications. At the forefront of these is the Qualified Manufacturers List (QML) methodology, in which the hardness of product is ''built-in'' through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to varying radiation scenarios. At the same time, there has been renewed interest in the use of commercial technology -- with its enhanced performance, reduced cost, and higher reliability -- in military and space systems. In this paper, we initially demonstrate the application of QML techniques to assure and control the radiation response of hardened technologies. Through several examples, we demonstrate intra-die, wafer-to-wafer, and lot-to-lot variations in a hardened technology. We observe 10 to 30% variations in key technology parameters that result from variability in geometry, process, and design layout. Radiation-induced degradation is seen to mirror preirradiation characteristics. We then evaluate commercial technologies and report considerably higher variability in radiation hardness, i.e., variations by a factor of two to five. This variability is shown to arise from a lack of control of technology parameters relevant to the radiation response, which a commercial manufacturer has no interest in controlling in a normal process flow

  2. Magnetic hyperthermia with hard-magnetic nanoparticles

    Science.gov (United States)

    Kashevsky, Bronislav E.; Kashevsky, Sergey B.; Korenkov, Victor S.; Istomin, Yuri P.; Terpinskaya, Tatyana I.; Ulashchik, Vladimir S.

    2015-04-01

    Recent clinical trials of magnetic hyperthermia have proved, and even hardened, the Ankinson-Brezovich restriction as upon magnetic field conditions applicable to any site of human body. Subject to this restriction, which is harshly violated in numerous laboratory and small animal studies, magnetic hyperthermia can relay on rather moderate heat source, so that optimization of the whole hyperthermia system remains, after all, the basic problem predetermining its clinical perspectives. We present short account of our complex (theoretical, laboratory and small animal) studies to demonstrate that such perspectives should be related with the hyperthermia system based on hard-magnetic (Stoner-Wohlfarth type) nanoparticles and strong low-frequency fields rather than with superparamagnetic (Brownian or Neél) nanoparticles and weak high-frequency fields. This conclusion is backed by an analytical evaluation of the maximum absorption rates possible under the field restriction in the ideal hard-magnetic (Stoner-Wohlarth) and the ideal superparamagnetic (single relaxation time) systems, by theoretical and experimental studies of the dynamic magnetic hysteresis in suspensions of movable hard-magnetic particles, by producing nanoparticles with adjusted coercivity and suspensions of such particles capable of effective energy absorption and intratumoral penetration, and finally, by successful treatment of a mice model tumor under field conditions acceptable for whole human body.

  3. Solving the hard problem of Bertrand's paradox

    Science.gov (United States)

    Aerts, Diederik; de Bianchi, Massimiliano Sassoli

    2014-08-01

    Bertrand's paradox is a famous problem of probability theory, pointing to a possible inconsistency in Laplace's principle of insufficient reason. In this article, we show that Bertrand's paradox contains two different problems: an "easy" problem and a "hard" problem. The easy problem can be solved by formulating Bertrand's question in sufficiently precise terms, so allowing for a non-ambiguous modelization of the entity subjected to the randomization. We then show that once the easy problem is settled, also the hard problem becomes solvable, provided Laplace's principle of insufficient reason is applied not to the outcomes of the experiment, but to the different possible "ways of selecting" an interaction between the entity under investigation and that producing the randomization. This consists in evaluating a huge average over all possible "ways of selecting" an interaction, which we call a universal average. Following a strategy similar to that used in the definition of the Wiener measure, we calculate such universal average and therefore solve the hard problem of Bertrand's paradox. The link between Bertrand's problem of probability theory and the measurement problem of quantum mechanics is also briefly discussed.

  4. New Hardness Results for Diophantine Approximation

    Science.gov (United States)

    Eisenbrand, Friedrich; Rothvoß, Thomas

    We revisit simultaneous Diophantine approximation, a classical problem from the geometry of numbers which has many applications in algorithms and complexity. The input to the decision version of this problem consists of a rational vector α ∈ ℚ n , an error bound ɛ and a denominator bound N ∈ ℕ + . One has to decide whether there exists an integer, called the denominator Q with 1 ≤ Q ≤ N such that the distance of each number Q ·α i to its nearest integer is bounded by ɛ. Lagarias has shown that this problem is NP-complete and optimization versions have been shown to be hard to approximate within a factor n c/ loglogn for some constant c > 0. We strengthen the existing hardness results and show that the optimization problem of finding the smallest denominator Q ∈ ℕ + such that the distances of Q·α i to the nearest integer are bounded by ɛ is hard to approximate within a factor 2 n unless {textrm{P}} = NP.

  5. The electronic structure of hard materials

    Science.gov (United States)

    Winarski, Robert Paul

    This research dissertation involves an experimental as well as a theoretical examination of the electronic structure of hard materials. The materials that are presented in this dissertation cover a wide class of materials, consisting of transition metal borides, irradiated polymer films, theoretically predicted superhard semiconductors, doped intermetallic alloys, and transition metal carbides. The borides are traditionally used in high temperature, hard coating applications, such as rocket nozzle linings, extreme wear surfaces, and corrosion coatings. Measurements of the borides appear to show that the bonding in these hard materials is primarily between the boron atoms in these systems. Also of note are the remarkably short interatomic distances between the boron atoms and between the boron and metal atoms in these materials. Irradiated polymer films are being developed for electronic applications, in the hopes that circuits can be developed that can benefit from the high thermal stability, dielectric properties, and mechanical properties provided by these materials. C3N4 is a theoretically predicted superhard material, and some of the first soft x-ray emission measurements of well-characterized samples of this compound are discussed in this work. Intermetallic alloys, in particular Ni3Al, are rather hard, but brittle metallic alloys. It has been found that the addition of boron atoms, in rather low concentrations, can increase the ductility of these alloys, allowing them to be utilized in a wider variety of applications. Measurements of this system have examined a question regarding the positioning of the boron atoms in the structures of this alloy. Finally, the transition metal carbides are used extensively as coatings in industrial applications such as cutting and grinding tools, and polishing compounds. Measurements of these materials suggest that the high degree of covalency between the metal and carbon atoms is primarily responsible for the hardness of

  6. Perception of the Hard Rock Brand by Czech University Students

    OpenAIRE

    Polák, Ivan

    2010-01-01

    The goal of this thesis is to understand perception of the Hard Rock brand in the Czech Republic among university students. Hard Rock Cafe Prague is a combination of a restaurant, bar, and rock club operated by the hospitality corporation Hard Rock International. The studied segment can be seen as a group of potential customers in long term, and this research should identify opportunities for growth of Czech guests. The thesis presents the process and results of Hard Rock brand research on th...

  7. Study on indium leaching from mechanically activated hard zinc residue

    OpenAIRE

    Yao J.H.; Li X.H.; Li Y.W.

    2011-01-01

    In this study, changes in physicochemical properties and leachability of indium from mechanically activated hard zinc residue by planetary mill were investigated. The results showed that mechanical activation increased specific surface area, reaction activity of hard zinc residue, and decreased its particle size, which had a positive effect on indium extraction from hard zinc residue in hydrochloric acid solution. Kinetics of indium leaching from unmilled and activated hard zinc residue...

  8. How Do You Like Your Equilibrium Selection Problems? Hard, or Very Hard?

    Science.gov (United States)

    Goldberg, Paul W.

    The PPAD-completeness of Nash equilibrium computation is taken as evidence that the problem is computationally hard in the worst case. This evidence is necessarily rather weak, in the sense that PPAD is only know to lie "between P and NP", and there is not a strong prospect of showing it to be as hard as NP. Of course, the problem of finding an equilibrium that has certain sought-after properties should be at least as hard as finding an unrestricted one, thus we have for example the NP-hardness of finding equilibria that are socially optimal (or indeed that have various efficiently checkable properties), the results of Gilboa and Zemel [6], and Conitzer and Sandholm [3]. In the talk I will give an overview of this topic, and a summary of recent progress showing that the equilibria that are found by the Lemke-Howson algorithm, as well as related homotopy methods, are PSPACE-complete to compute. Thus we show that there are no short cuts to the Lemke-Howson solutions, subject only to the hardness of PSPACE. I mention some open problems.

  9. Systematic hardness measurements on some rare earth garnet crystals

    Indian Academy of Sciences (India)

    D B Sirdeshmukh; L Sirdeshmukh; K G Subhadra; K Kishan Rao; S Bal Laxman

    2001-10-01

    Microhardness measurements were undertaken on twelve rare earth garnet crystals. In yttrium aluminium garnet and gadolinium gallium garnet, there was no measurable difference in the hardness values of pure and nominally Nd-doped crystals. The hardness values were correlated with the lattice and elastic constants. An analysis of hardness data in terms of the interatomic binding indicated a high degree of covalency.

  10. Standard test methods for Rockwell hardness of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 These test methods cover the determination of the Rockwell hardness and the Rockwell superficial hardness of metallic materials by the Rockwell indentation hardness principle. This standard provides the requirements for Rockwell hardness machines and the procedures for performing Rockwell hardness tests. 1.2 This standard includes additional requirements in annexes: Verification of Rockwell Hardness Testing Machines\tAnnex A1 Rockwell Hardness Standardizing Machines\tAnnex A2 Standardization of Rockwell Indenters\tAnnex A3 Standardization of Rockwell Hardness Test Blocks\tAnnex A4 Guidelines for Determining the Minimum Thickness of a Test Piece\tAnnex A5 Hardness Value Corrections When Testing on Convex Cylindrical Surfaces\tAnnex A6 1.3 This standard includes nonmandatory information in appendixes which relates to the Rockwell hardness test. List of ASTM Standards Giving Hardness Values Corresponding to Tensile Strength\tAppendix X1 Examples of Procedures for Determining Rockwell Hardness Uncertainty\tAppendi...

  11. Hard spheres at a planar hard wall: Simulations and density functional theory

    Directory of Open Access Journals (Sweden)

    R.L. Davidchack

    2016-03-01

    Full Text Available Hard spheres are a central and important model reference system for both homogeneous and inhomogeneous fluid systems. In this paper we present new high-precision molecular-dynamics computer simulations for a hard sphere fluid at a planar hard wall. For this system we present benchmark data for the density profile ρ(z at various bulk densities, the wall surface free energy γ, the excess adsorption Γ, and the excess volume v_{ex}, which is closely related to Γ. We compare all benchmark quantities with predictions from state-of-the-art classical density functional theory calculations within the framework of fundamental measure theory. While we find overall good agreement between computer simulations and theory, significant deviations appear at sufficiently high bulk densities.

  12. Hard machining under dry conditions with hard PVD coatings on cemented carbide endmills

    International Nuclear Information System (INIS)

    Machining of hardened steel needs cutting tools for extreme conditions. Not only the cemented carbide tool material, but also the hard or ultra hard coating determines the tool life and cutting performance on the work piece. For milling operation in hardened material 1.2379 with a hardness between 60 and 62 HRc, endmills coated with different TiAlN layers in single or multilayer design and also top coatings with friction performance are used. Cutting tests with investigations of the wear on the cutting edge and in situ infrared temperature measurements by video camera showed large differences in tool performance. According to these results the limitation of cutting time or cutting length is, in some cases, not only caused by the wear on the tool, but also by the surface temperature of the work piece material. (author)

  13. Ariel 5 hard X-ray observations

    International Nuclear Information System (INIS)

    Results from the hard X-ray detector (8cm2 area, 80 f.w.h.m. field of view, energy range 26-1200 keV) are reviewed in the context of observations by other groups. At least three different classes of galactic sources are studied by this detector. In the first, magnetospheric control of the emission, which seems to be a modified thermal spectrum is dominant. Examples are Cen X-3, Her X-1, AO535 + 26 and GX 301 - 2. So far, only direct evidence on the magnetic field strength from cyclotron line emission has come from Her X-1. In the second, the characteristics are a power law spectrum extending to over about 200 keV and fast aperiodic time variations with little evidence of the presence of strong magnetic fields. Inverse Compton production of the X-ray photons seems important here. Examples are Cyg X-1, AO620-00, Ser X-1 and perhaps Cir X-1, although this last object suffers periodic heavy low energy absorption. The third is the white dwarf emitted class, e.g. AM Herculis and possibly AM Canum Venaticorum; sources in this class surprisingly tend to exhibit a power law rather than a thermal spectral shape. Sco X-1 and Sco X-2 are perhaps a fourth class of object. Hard X-ray upper limits obtained from a survey of COS-B γ-ray source positions are discussed. Further attempts to find hard X-ray emission from the galactic centre X-ray burst sources are mentioned. (author)

  14. Dynamic instability of the hard turning process

    Directory of Open Access Journals (Sweden)

    J. Kopač

    2006-04-01

    Full Text Available Purpose: Purpose of this paper is consideration of dynamic behavior of the hard turning process. There are several indicators which could confirm assumption of turning instability (depth of cutting, high ratio of forces Fc/Fp, small tool nose radius, and non-uniform stress distribution over tool/workpiece contact. Lead edge angle and passive force Fp are strongly depend on depth of cutting in hard turning what additionally increase instability.Design/methodology/approach: Numerical calculation and experimental tests have been done to evaluate the rate of cutting instability while using and comparing different process monitoring sensors, and acquisition techniques based on PC platform.Findings: It was found that high chip thickness alteration occur because of cutting depth vary for a value of some 60 % and even more if Fp force signal is analyzing when machine tool has inadequate stiffness.Research limitations/implications: Results and findings presented in this paper are qualitative and might be slightly different in other cutting condition (e.g. if wiper inserts are used. Also there are no experiences with coated workpieces or with workpiece material with low deformation energy.Practical implications: Assuming that a hard turning is a semi finishing or finishing process, surface finish is of big relevance. Surface roughness is a consequence of both cutting instability and of tool/workpiece loading condition. Results of test indicates an optimal cutting depth for final pass when minimum surface roughness can be achieved what can be valuable for cutting regime determination. Furthermore, more effective use of the machine tool performances might be achieved.Originality/value: Originality of the paper is in analysis of sources of turning instability (variable depth of cutting combined with side edge angle and tool nose radius which lead primary to condition where Fp sensing data does not fit to the normal distribution and secondary to cyclic push

  15. CO2 laser milling of hard tissue

    Science.gov (United States)

    Werner, Martin; Ivanenko, Mikhail; Harbecke, Daniela; Klasing, Manfred; Steigerwald, Hendrik; Hering, Peter

    2007-02-01

    Drilling of bone and tooth tissue belongs to recurrent medical procedures (screw- and pin-bores, bores for implant inserting, trepanation etc.). Small round bores can be in general quickly produced with mechanical drills. Problems arise however by angled drilling, by the necessity to fulfill the drilling without damaging of sensitive soft tissue beneath the bone, or by the attempt to mill precisely noncircular small cavities. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The "milling" is done with a CO2 laser (10.6 μm) with pulse duration of 50 - 100 μs, combined with a PC-controlled galvanic beam scanner and with a fine water-spray, which helps to avoid thermal side-effects. The damaging of underlying soft tissue can be prevented through control of the optical or acoustical ablation signal. The ablation of hard tissue is accompanied with a strong glowing, which is absent during the laser beam action on soft tissue. The acoustic signals from the diverse tissue types exhibit distinct differences in the spectral composition. Also computer image analysis could be a useful tool to control the operation. Laser "milling" of noncircular cavities with 1 - 4 mm width and about 10 mm depth is particularly interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser "milling" of the cavities without thermal damage and with minimal tapering. It included exploration of different filling patterns (concentric rings, crosshatch, parallel lines and their combinations), definition of maximal pulse duration, repetition rate and laser power, optimal position of the spray. The optimized results give evidences for the applicability of the CO2 laser for biologically tolerable "milling" of deep cavities in the hard tissue.

  16. Hard X-ray Variability of AGN

    OpenAIRE

    Beckmann, V.; Barthelmy, S. D.; Courvoisier, T. J. -L.; Gehrels, N.; Soldi, S.; Tueller, J.; Wendt, G.

    2007-01-01

    Aims: Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X-ray range above 20 keV. Methods: The first 9 months of the Swift/BAT all-sky survey are used to study the 14 - 195 keV variability of the 44 brightest AGN. The sources have been selected due to their detection significance of >10 sigma. We tested the variability using a maximum likelihood estimator and by analysing the structure function....

  17. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  18. Classic Nintendo Games are (NP-)Hard

    CERN Document Server

    Aloupis, Greg; Guo, Alan

    2012-01-01

    We prove NP-hardness results for five of Nintendo's largest video game franchises: Mario, Donkey Kong, Legend of Zelda, Metroid, and Pokemon. Our results apply to Super Mario Bros. 1, 3, Lost Levels, and Super Mario World; Donkey Kong Country 1-3; all Legend of Zelda games except Zelda II: The Adventure of Link; all Metroid games; and all Pokemon role-playing games. For Mario and Donkey Kong, we show NP-completeness. In addition, we observe that several games in the Zelda series are PSPACE-complete.

  19. Combinatorics of bicubic maps with hard particles

    International Nuclear Information System (INIS)

    We present a purely combinatorial solution of the problem of enumerating planar bicubic maps with hard particles. This is done by the use of a bijection with a particular class of blossom trees with particles, obtained by an appropriate cutting of the maps. Although these trees have no simple local characterization, we prove that their enumeration may be performed upon introducing a larger class of 'admissible' trees with possibly doubly occupied edges and summing them with appropriate signed weights. The proof relies on an extension of the cutting procedure allowing for the presence on the maps of special non-sectile edges. The admissible trees are characterized by simple local rules, allowing eventually for an exact enumeration of planar bicubic maps with hard particles. We also discuss generalizations for maps with particles subject to more general exclusion rules and show how to re-derive the enumeration of quartic maps with Ising spins in the present framework of admissible trees. We finally comment on a possible interpretation in terms of branching processes

  20. Lasers and hard-tissue interactions

    Science.gov (United States)

    Makropoulou, Mersini I.; Papagiakoumou, Eirini I.

    2004-06-01

    The hard tissue laser ablation and the relevant laser applications on dental tissues have attracted several investigators, since the ablation efficiency, the lateral thermal and/or mechanical damage and the final surface characteristics must be optimised, in order to fulfil the efficient and safe removal of pathological dental areas in a clinical environment. For example, it was theoretically predicted that the lateral tissue thermal damage might be limited when the laser intensity is high and the interaction time is short. In this case the Q-switched Er:YAG laser operating with a pulse length below the thermal relaxation time of the irradiated tissue, is considered to be very effective. Therefore, the efficacy of the Q-switched Er:YAG laser, versus the free-running operation mode, on dentine ablation was studied, as well as the morphological changes at the irradiated dentine surface. Additionally, the interaction of nanosecond UV laser pulses and IR/visible picosecond laser pulses with hard tissue samples was investigated for comparative evaluation of the different laser ablation mechanisms.

  1. Generalized Soft-and-Hard/DB Boundary

    CERN Document Server

    Lindell, Ismo V

    2016-01-01

    A novel class of boundary conditions is introduced as a generalization of the previously defined class of soft-and-hard/DB (SHDB) boundary conditions. It is shown that the conditions for the generalized soft-and-hard/DB (GSHDB) boundary arise most naturally in a simple and straightforward manner by applying four-dimensional differential-form and dyadic formalism. At a given boundary surface, the GSHDB conditions are governed by two one-forms. In terms of Gibbsian 3D vector and dyadic algebra the GSHDB conditions are defined in terms of two vectors tangential to the boundary surface and two scalars. Considering plane-wave reflection from the GSHDB boundary, for two eigenpolarizations, the GSHDB boundary can be replaced by the PEC or PMC boundary. Special attention is paid to the problem of plane waves matched to the GSHDB boundary, defined by a 2D dispersion equation for the wave vector, making the reflection dyadic indeterminate. Examples of dispersion curves for various chosen parameters of the GSHDB boundar...

  2. Solving the hard problem of Bertrand's paradox

    International Nuclear Information System (INIS)

    Bertrand's paradox is a famous problem of probability theory, pointing to a possible inconsistency in Laplace's principle of insufficient reason. In this article, we show that Bertrand's paradox contains two different problems: an “easy” problem and a “hard” problem. The easy problem can be solved by formulating Bertrand's question in sufficiently precise terms, so allowing for a non-ambiguous modelization of the entity subjected to the randomization. We then show that once the easy problem is settled, also the hard problem becomes solvable, provided Laplace's principle of insufficient reason is applied not to the outcomes of the experiment, but to the different possible “ways of selecting” an interaction between the entity under investigation and that producing the randomization. This consists in evaluating a huge average over all possible “ways of selecting” an interaction, which we call a universal average. Following a strategy similar to that used in the definition of the Wiener measure, we calculate such universal average and therefore solve the hard problem of Bertrand's paradox. The link between Bertrand's problem of probability theory and the measurement problem of quantum mechanics is also briefly discussed

  3. The rheology of adhesive hard sphere dispersions

    Science.gov (United States)

    Woutersen, A. T. J. M.; de Kruif, C. G.

    1991-04-01

    The influence of an attractive interparticle potential on the rheology of a sterically stabilized silica dispersion was investigated. Using a marginal solvent, there was an effective attraction between the particles which depended on the temperature. Three experiments in which different properties of the dispersion were probed showed that a square well model can be used to describe the temperature dependence of the pair potential. The turbidity of a dilute dispersion was measured as a function of the volume fraction and the temperature. Using dynamic light scattering techniques, the effect of the strength of the interparticle attraction on the diffusion coefficient was investigated. Furthermore, the steady shear viscosity was measured as a function of the volume fraction and the temperature. A microscopic theory for the low shear viscosity of a semidilute dispersion of adhesive hard spheres was successfully used to determine the interaction parameters. Viscosity measurement on dense suspensions showed that while the system is still in the one-phase state, temporal aggregates are formed by the interparticle forces which are disrupted by both shear and Brownian motion of the particles. The shear thinning behavior of a concentrated dispersion of adhesive hard spheres scales in a dimensionless shear stress. This group is the ratio of the forces, arising from the shear and the interparticle potential.

  4. Statistical physics of hard optimization problems

    International Nuclear Information System (INIS)

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfy ability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named ”locked” constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfy ability.

  5. Using Neighborhood Diversity to Solve Hard Problems

    CERN Document Server

    Ganian, Robert

    2012-01-01

    Parameterized algorithms are a very useful tool for dealing with NP-hard problems on graphs. Yet, to properly utilize parameterized algorithms it is necessary to choose the right parameter based on the type of problem and properties of the target graph class. Tree-width is an example of a very successful graph parameter, however it cannot be used on dense graph classes and there also exist problems which are hard even on graphs of bounded tree-width. Such problems can be tackled by using vertex cover as a parameter, however this places severe restrictions on admissible graph classes. Michael Lampis has recently introduced neighborhood diversity, a new graph parameter which generalizes vertex cover to dense graphs. Among other results, he has shown that simple parameterized algorithms exist for a few problems on graphs of bounded neighborhood diversity. Our article further studies this area and provides new algorithms parameterized by neighborhood diversity for the p-Vertex-Disjoint Paths, Graph Motif and Prec...

  6. Statistical physics of hard optimization problems

    Science.gov (United States)

    Zdeborová, Lenka

    2009-06-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named "locked" constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability.

  7. Orientational Ordering and Phase Behaviour of Binary Mixtures of Hard Spheres and Hard Spherocylinders.

    Czech Academy of Sciences Publication Activity Database

    Wu, L.; Malijevský, Alexandr; Jackson, G.; Muller, E.A.; Avendano, C.

    2015-01-01

    Roč. 143, č. 4 (2015), s. 044906. ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA13-02938S Institutional support: RVO:67985858 Keywords : phase behaviour * liquid crystals * hard spheres Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.952, year: 2014

  8. Analysis on Dynamic Response of Hard-Soft-Hard Sandwich Panel Under Blast Loading

    Institute of Scientific and Technical Information of China (English)

    DONG Yongxiang; FENG Shunshan; JIN Jun

    2006-01-01

    Surface contact explosion experiments have been performed for the study of dynamic response of the hard-soft-hard sandwich panel under blast loading.Experimental results have shown that there are four damage modes,including explosion cratering,scabbing of the backside,radial cracking induced failure and circumferential cracking induced failure.It also illustrates that the foam material sandwiched in the multi-layered media has an important effect on damage patterns.The phenomena encountered have been analyzed by the calculation with ALE method.Meanwhile,the optimal analysis of foam material thickness and position in the sandwich panel were performed in terms of experimental and numerical analysis.The proper thickness proportion of the soft layer is about 20% to the thickness of sandwich panel and the thickness of the upper hard layer and lower hard layer is in the ratio of 7 to 3 under the condition in this paper when the total thickness of soft layer remains constant.

  9. Hard-Boiled for Hard Times in Leonardo Padura Fuentes's Detective Fiction

    Science.gov (United States)

    Song, H. Rosi

    2009-01-01

    Focusing on Leonardo Padura Fuentes's hard-boiled fiction, this essay traces the origin and evolution of the genre in Cuba. Padura Fuentes has challenged the officially sanctioned socialist "literatura policial" that became popular in the 1970s and 1980s. creating a new model of criticism that is not afraid to confront the island's socio-economic…

  10. Distribution of Grain Hardness in Chinese Wheats and Genetic Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yan-hua; HE Zhong-hu; YAN Jun; ZHANG Yan; WANG De-sen; ZHOU Gui-ying

    2002-01-01

    A hundred winter wheat and 41 spring wheat cultivars and advanced lines were used to investigate the distribution of grain hardness in Chinese wheats and correlations between grain hardness and other kernel traits. P1, P2, F1, F2 and F3 from three crosses, i. e. , Liken2/Yumai2, 85Zhong33/Wenmai6 and 85Zhong33/95Zhong459 were sown to study the genetics of grain hardness. Significant correlation was observed between hardness measured by Single Kernel Characteristic System 4100 (SKCS 4100) and Near Infrared (NIR) Spectroscopy, r ranging from 0. 85 to 0.94. Chinese wheat is a mixed population in terms of hardness, ranging from very soft to very hard. For autumn-sown wheat, on average, grain hardness decreases from north to south and spring-sown wheat is dominant with hard type. Hardness is negatively associated with flour color, and its associations with flour yield and ash content differ in winter and spring wheats. Grain hardness is controlled by a major gene and several minor genes with additive effect mostly, but dominant effect is also observed, with heritability of 0.78.

  11. Aespoe hard rock laboratory. Annual report 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2010 is given below

  12. Explicit Optimal Hardness via Gaussian stability results

    CERN Document Server

    De, Anindya

    2012-01-01

    The results of Raghavendra (2008) show that assuming Khot's Unique Games Conjecture (2002), for every constraint satisfaction problem there exists a generic semi-definite program that achieves the optimal approximation factor. This result is existential as it does not provide an explicit optimal rounding procedure nor does it allow to calculate exactly the Unique Games hardness of the problem. Obtaining an explicit optimal approximation scheme and the corresponding approximation factor is a difficult challenge for each specific approximation problem. An approach for determining the exact approximation factor and the corresponding optimal rounding was established in the analysis of MAX-CUT (KKMO 2004) and the use of the Invariance Principle (MOO 2005). However, this approach crucially relies on results explicitly proving optimal partitions in Gaussian space. Until recently, Borell's result (Borell 1985) was the only non-trivial Gaussian partition result known. In this paper we derive the first explicit optimal...

  13. Radiation hard avalanche photodiodes for CMS ECAL

    CERN Document Server

    Kuznetsov, A; Britvitch, A; Deiters, K; Egeland, R; Gilbert, B; Godinovic, N; Ingram, Q; Lester, E; Musienko, Y; Puljak, I; Renker, D; Reucroft, S; Rusack, R W; Sakhelashvili, T M; Singovsky, A V; Soric, I; Swain, J D

    2003-01-01

    The photo detectors of the CMS electromagnetic calorimeter have to operate in a rather hostile environment, in a strong magnetic field of 4T and under unprecedented radiation levels. Avalanche Photo Diodes (APDs) have been chosen to detect the scintillation light of the 62,000 lead tungstate crystals in the barrel part of the calorimeter. After a 6 year long R&D work Hamamatsu Photonics produces APDs with a structure that is basically radiation hard. Only a few percent of the delivered APDs are weak due to defects at the surface caused by dust particles in the production process. Since a reliability of 99.9% is required, a method to detect weak APDs before they are built into the detector had to be developed. The described screening method is a combination of **6**0Co irradiations and annealing under bias of all APDs and irradiations with hadrons on a sampling basis.

  14. Aespoe hard rock laboratory. Annual report 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2010 is given below

  15. Aespoe Hard Rock Laboratory. Annual Report 2011

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-03-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2011 is given below.

  16. Using Cell Phone Keyboards Is (NP) Hard

    Science.gov (United States)

    Boothe, Peter

    Sending text messages on cell phones which only contain the keys 0 through 9 and # and * can be a painful experience. We consider the problem of designing an optimal mapping of numbers to sets of letters to act as an alternative to the standard {2→{abc}, 3→{def}...}. Our overall goal is to minimize the expected number of buttons that must be pressed to enter a message in English. Some variations of the problem are efficiently solvable, either by being small instances or by being in P, but the most realistic version of the problem is NP hard. To prove NP-completeness, we describe a new graph coloring problem UniquePathColoring. We also provide numerical results for the English language on a standard corpus which describe several mappings that improve upon the standard one. With luck, one of these new mappings will achieve success similar to that of the Dvorak layout for computer keyboards.

  17. Radiation hardness of the LHCb Outer Tracker

    International Nuclear Information System (INIS)

    This paper presents results on the radiation hardness of the LHCb Outer Tracker (OT) during LHC operation in 2010 and 2011. Modules of the OT have shown to suffer from ageing effects that lead to gain loss, after irradiation in the laboratory. Under irradiation at moderate intensities an insulating layer is formed on the anode wire of the OT straw cells. This ageing effect is caused by contamination of the counting gas due to outgassing of the glue used in the construction of the OT modules. Two methods to monitor gain stability in the OT are presented: module scans with radioactive sources and the study of hit efficiency as a function of amplifier threshold. No gain loss is observed after receiving 1.3 fb−1 of integrated luminosity corresponding to an integrated charge of 0.055 C/cm in the hottest spot of the detector.

  18. Nanomechanics of hard films on compliant substrates.

    Energy Technology Data Exchange (ETDEWEB)

    Reedy, Earl David, Jr. (Sandia National Laboratories, Albuquerque, NM); Emerson, John Allen (Sandia National Laboratories, Albuquerque, NM); Bahr, David F. (Washington State University, Pullman, WA); Moody, Neville Reid; Zhou, Xiao Wang; Hales, Lucas (University of Minnesota, Minneapolis, MN); Adams, David Price (Sandia National Laboratories, Albuquerque, NM); Yeager,John (Washington State University, Pullman, WA); Nyugen, Thao D. (Johns Hopkins University, Baltimore, MD); Corona, Edmundo (Sandia National Laboratories, Albuquerque, NM); Kennedy, Marian S. (Clemson University, Clemson, SC); Cordill, Megan J. (Erich Schmid Institute, Leoben, Austria)

    2009-09-01

    a result, our understanding of the critical relationship between adhesion, properties, and fracture for hard films on compliant substrates is limited. To address this issue, we integrated nanomechanical testing and mechanics-based modeling in a program to define the critical relationship between deformation and fracture of nanoscale films on compliant substrates. The approach involved designing model film systems and employing nano-scale experimental characterization techniques to isolate effects of compliance, viscoelasticity, and plasticity on deformation and fracture of thin hard films on substrates that spanned more than two orders of compliance magnitude exhibit different interface structures, have different adhesion strengths, and function differently under stress. The results of this work are described in six chapters. Chapter 1 provides the motivation for this work. Chapter 2 presents experimental results covering film system design, sample preparation, indentation response, and fracture including discussion on the effects of substrate compliance on fracture energies and buckle formation from existing models. Chapter 3 describes the use of analytical and finite element simulations to define the role of substrate compliance and film geometry on the indentation response of thin hard films on compliant substrates. Chapter 4 describes the development and application of cohesive zone model based finite element simulations to determine how substrate compliance affects debond growth. Chapter 5 describes the use of molecular dynamics simulations to define the effects of substrate compliance on interfacial fracture of thin hard tungsten films on silicon substrates. Chapter 6 describes the Workshops sponsored through this program to advance understanding of material and system behavior.

  19. New materials for radiation hard semiconductor detectors

    CERN Document Server

    Sellin, P J; CERN. Geneva

    2006-01-01

    We present a review of the current status of research into new semiconductor materials for use as particle tracking detectors in very high radiation environments. This work is carried out within the framework of the CERN RD50 collaboration, which is investigating detector technologies suitable for operation at the proposed Super-LHC facility (SLHC). Tracking detectors operating at the SLHC in this environment will have to be capable of withstanding radiation levels arising from a luminosity of 1035 cm-2s-1 which will present severe challenges to current tracking detector technologies. The "new materials" activity within RD50 is investigating the performance of various semiconductor materials that potentially offer radiation hard alternatives to silicon devices. The main contenders in this study are silicon carbide, gallium nitride and amorphous silicon. In this paper we review the current status of these materials, in terms of material quality, commercial availability, charge transport properties, and radiati...

  20. Aespoe Hard Rock Laboratory. Annual Report 2011

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2011 is given below

  1. Hard Probes in Heavy-Ion Physics

    CERN Document Server

    Renk, Thorsten

    2012-01-01

    The aim of ultrarelativistic heavy ion physics is to study collectivity and thermodynamics of Quantum Chromodynamics (QCD) by creating a transient small volume of matter with extreme density and temperature. There is experimental evidence that most of the particles created in such a collision form indeed a thermalized system characterized by collective response to pressure gradients. However, a numerically small subset of high transverse momentum ($P_T$) processes takes place independent of the bulk, with the outgoing partons subsequently propagating through the bulk medium. Understanding the modification of such 'hard probes' by the bulk medium is an important part of the efforts to determine the properties of hot and dense QCD matter. In this paper, current developments are reviewed.

  2. TOPOGRAPHIC SITE RESPONSE AT HARD ROCK SITES

    Science.gov (United States)

    Yong, A. K.; Hough, S. E.

    2009-12-01

    Site (material impedance) and topographic (geometric form) effects are known to be key factors that influence seismic ground motions. To characterize site effects, Yong et al. (2009) developed a terrain-based Vs30 prediction model using an automated classification method (Iwahashi and Pike, 2007) that relied on taxonomic criteria (slope gradient, local convexity and surface texture) developed from geomorphometry to identify 16 terrain types from a 1-km spatial resolution (SRTM30 data) digital elevation model of California. On the basis that the underlying framework for this model contains parameters (esp., local convexity) which aptly describe the geometry (i.e., base to height ratio) of relief features that are known to also control the behavior of ground motions (Bouchon, 1973), we extend our investigation to study topographic effects. Focusing on sites that would generally be considered “hard rock,” the classification scheme distinguishes 7 separate terrain types ranging from “moderately eroded mountains” to “well dissected alpine summits.” Observed 1-Hz amplification factors at Southern California Seismographic Network sites reveal a weak but systematic correlation with these 7 terrain types. Significant scatter is also found within each terrain type; typical standard deviations of logarithmic amplification factors are 0.2-0.3. Considering stations that have high amplification factors, we find some that have apparently been misclassified due to data resolution limitations. Many of the remaining stations with higher than expected amplifications are located on or near topographic peaks or ridges. The unusually high amplification factors at hard-rock sites, typically factors of 1.5-2, can most plausibly be explained as a topographic effect.

  3. Systematics of compression of hard materials

    International Nuclear Information System (INIS)

    Hard materials have the remarkable property that relatively little internal energy of shock compression is deposited as temperature and associated thermal pressure. As a result, the Hugoniot curve is nearly coincident with the 0-K isotherm. Since the isentrope is intermediate between isotherm and Hugoniot, all three curves of a given hard material are nearly coincident. Published data for diamond and Gd3Ga5O12 (GGG) show this to be the case up to 600 GPa and 80 GPa, respectively. Above 100 GPa on the Hugoniot the incompressibilities, defined to be the derivative of pressure with respect to compression, of GGG, other oxides and even CaF2 are significantly greater than that of diamond. In fact, above 100 GPa CaF2 might well be the least compressible of any known material. Little EOS data of weakly compressible materials have been measured in a diamond anvil cell (DAC) above a few tens of GPa at 300 K because these materials often become amorphous, which means density in a DAC cannot be measured by X-ray diffraction. Amorphization suggests the onset of a sluggish phase transition. On the other hand, Hugoniot experiments readily measure density changes caused by compression and phase transitions independent of material structure. Hugoniots of weakly compressible materials suggest experiments to determine structures and compressibilities in laser-heated DACs at 100 GPa pressures, as has been done with TiO2 and perovskite, and Hugoniot data might provide estimates of compressions of oxides representative of the deep interiors of rocky planets in other solar systems

  4. Coendangered hard-ticks: threatened or threatening?

    Science.gov (United States)

    Mihalca, Andrei Daniel; Gherman, Călin Mircea; Cozma, Vasile

    2011-01-01

    The overwhelming majority of animal conservation projects are focused on vertebrates, despite most of the species on Earth being invertebrates. Estimates state that about half of all named species of invertebrates are parasitic in at least one stage of their development. The dilemma of viewing parasites as biodiversity or pest has been discussed by several authors. However, ticks were omitted. The latest taxonomic synopses of non-fossil Ixodidae consider valid 700 species. Though, how many of them are still extant is almost impossible to tell, as many of them are known only from type specimens in museums and were never collected since their original description. Moreover, many hosts are endangered and as part of conservation efforts of threatened vertebrates, a common practice is the removal of, and treatment for external parasites, with devastating impact on tick populations. There are several known cases when the host became extinct with subsequent coextinction of their ectoparasites. For our synoptic approach we have used the IUCN status of the host in order to evaluate the status of specifically associated hard-ticks. As a result, we propose a number of 63 coendangered and one extinct hard-tick species. On the other side of the coin, the most important issue regarding tick-host associations is vectorial transmission of microbial pathogens (i.e. viruses, bacteria, protozoans). Tick-borne diseases of threatened vertebrates are sometimes fatal to their hosts. Mortality associated with pathogens acquired from ticks has been documented in several cases, mostly after translocations. Are ticks a real threat to their coendangered host and should they be eliminated? Up to date, there are no reliable proofs that ticks listed by us as coendangered are competent vectors for pathogens of endangered animals. PMID:21554736

  5. Coendangered hard-ticks: threatened or threatening?

    Directory of Open Access Journals (Sweden)

    Cozma Vasile

    2011-05-01

    Full Text Available Abstract The overwhelming majority of animal conservation projects are focused on vertebrates, despite most of the species on Earth being invertebrates. Estimates state that about half of all named species of invertebrates are parasitic in at least one stage of their development. The dilemma of viewing parasites as biodiversity or pest has been discussed by several authors. However, ticks were omitted. The latest taxonomic synopses of non-fossil Ixodidae consider valid 700 species. Though, how many of them are still extant is almost impossible to tell, as many of them are known only from type specimens in museums and were never collected since their original description. Moreover, many hosts are endangered and as part of conservation efforts of threatened vertebrates, a common practice is the removal of, and treatment for external parasites, with devastating impact on tick populations. There are several known cases when the host became extinct with subsequent coextinction of their ectoparasites. For our synoptic approach we have used the IUCN status of the host in order to evaluate the status of specifically associated hard-ticks. As a result, we propose a number of 63 coendangered and one extinct hard-tick species. On the other side of the coin, the most important issue regarding tick-host associations is vectorial transmission of microbial pathogens (i.e. viruses, bacteria, protozoans. Tick-borne diseases of threatened vertebrates are sometimes fatal to their hosts. Mortality associated with pathogens acquired from ticks has been documented in several cases, mostly after translocations. Are ticks a real threat to their coendangered host and should they be eliminated? Up to date, there are no reliable proofs that ticks listed by us as coendangered are competent vectors for pathogens of endangered animals.

  6. GRAIN QUALITY AND NORTH AMERICAN HARD WHEAT EXPORTS

    OpenAIRE

    Wilson, William W.; Dahl, Bruce L.

    1998-01-01

    Past debate on competition and quality in international wheat markets has focused on class and country of origin as the salient source of differentiation. This study analyzes changes in demand for both wheat classes and grades. Comparisons are made between Canadian and U.S. hard wheats, principal competitors in the hard wheat market. Both countries are dominant producers of Hard Red Spring Wheat (HRS in the United States and Canadian Western Red Spring [CWRS] in Canada); the United States is ...

  7. Foreign Market Entry Mode Choice: Hard - And Soft Services

    OpenAIRE

    Majkgård, A; D. D. Sharma

    1999-01-01

    Research from service firms show that one group of studies suggest that entry mode choices by manufacturing firms are generalizable to service firms. Results from another group of studies contradict that view. In this paper we classify services in hard services and soft services, hard services are grouped with manufacturing firms in terms of foreign market entry mode choices. The data consists of 362 international ,^er\\ ice firms The findings shows that hard services do not significantly diff...

  8. Yet Another Graph Partitioning Problem is NP-Hard

    OpenAIRE

    Lewis, Ryan H.

    2014-01-01

    Recently a large number of graph separator problems have been proven to be \\textsc{NP-Hard}. Amazingly we have found that $\\alpha$-Subgraph-Balanced-Vertex-Separator, an important variant, has been overlooked. In this work ``Yet Another Graph Partitioning Problem is NP-Hard" we present the surprising result that $\\alpha$-Subgraph-Balanced-Vertex-Separator is $NP$-Hard. This is despite the fact that the constraints of our new problem are harder to satisfy than the original problem.

  9. Soft is hard and hard is easy: learning technologies and social media

    Directory of Open Access Journals (Sweden)

    Jon Dron

    2013-03-01

    Full Text Available Questo articolo riguarda principalmente la natura delle tecnologie per apprendere, con una particolare attenzione ai social media. Muovendo dalla definizione fornita da W. Brian Arthur delle tecnologie come un insieme di fenomeni orchestrati per un qualche uso, l’articolo amplia la teoria di Arthur ridefinendo e allargando la distinzione comunemente accettata tra tecnologie soft e hard, laddove le tecnologie soft sono intese come quelle che richiedono l’orchestrazione di fenomeni da parte degli esseri umani, mentre le tecnologie hard sono quelle per le quali l’orchestrazione è predeterminata o incorporata. Le tecnologie per apprendere sono quelle in cui le pedagogie (anch’esse tecnologie sono parte dell’insieme. Le conseguenze di questa prospettiva vengono esplorate nel quadro di diversi modelli pedagogici e in relazione agli approcci basati sul social learning in una varietà di contesti, dai corsi per corrispondenza ai MOOC.

  10. Microstructure of starch granule related to kernel hardness in corn

    OpenAIRE

    M. Gaytán-Martínez; J. D. Figueroa-Cárdenas; M. L. Reyes-Vega; F. Rincón-Sánchez; E. Morales-Sánchez

    2006-01-01

    The kernel hardness of 21 corn (Zea mays L.) cultivars was studied in relation to texture, flotation index, size and arrangement of the starch granules within the endosperm, using scanning electron microscope. Hardness (7.6 – 16.9 kg-f) was related to the size and the arrangement of the starch granules within the endosperm. Hard corn had large and small polygonal granules in a compact protein matrix. Data obtained from scanning electron microscopy showed a positive correlation of hardness wit...

  11. Study Of Microstructure And Hardness Of Assab Corrax Steel Annealing

    International Nuclear Information System (INIS)

    Hardness testing and microstructures investigation have been performed at annealed Assab Corrax steel. This preliminary research is gain to look for the high temperature operation resisting materials. The steels were annealed to observe grains and hardness changes in two ways; annealing-temperature constant (400oC) and annealing-time hold constant (4 hours). The results show that the hardness vs. time-hold fluctuates between 200 Hv and 400 Hv, meanwhile it tends to increase due to precipitation hardening by means annealing temperatures. In summary, the hardness is unpredictable by means time-hold and it improves due to precipitation role. The surface micrographs support the phenomena

  12. A study of the hard magnetic properties in different hard magnetic materials

    International Nuclear Information System (INIS)

    The magnetic properties of several hard magnetic materials have been investigated to determine any trends in their magnetic characteristics. The materials studied were Nd15Fe77B8, SmCo5, Sm2 (Co,Fe,Cu,Zr)17, strontium ferrite magnets and single domain particles of Ba-ferrite and Cu-Mn-Al. The initial magnetization curves, field dependence of coercivity and remanence curves were measured

  13. Soft is hard and hard is easy: learning technologies and social media

    OpenAIRE

    Jon Dron

    2013-01-01

    Questo articolo riguarda principalmente la natura delle tecnologie per apprendere, con una particolare attenzione ai social media. Muovendo dalla definizione fornita da W. Brian Arthur delle tecnologie come un insieme di fenomeni orchestrati per un qualche uso, l’articolo amplia la teoria di Arthur ridefinendo e allargando la distinzione comunemente accettata tra tecnologie soft e hard, laddove le tecnologie soft sono intese come quelle che richiedono l’orchestrazione di fenomeni da parte deg...

  14. The phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids

    OpenAIRE

    Oyarzun, B.A.; Van Westen, T.; Vlugt, T.J.H.

    2013-01-01

    he liquid crystal phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids are studied by constant pressure Monte Carlo simulations. An extensive study on the phase behavior of linear fluids with a length of 7, 8, 9, 10, 11, 12, 13, 14, 15, and 20 beads is carried out. The phase behavior of partially flexible fluids with a total length of 8, 10, 14, and 15 beads and with different lengths for the linear part is als...

  15. Aespoe Hard Rock Laboratory Annual Report 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-08-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  16. Aespoe Hard Rock Laboratory. Annual report 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The surface and borehole investigations and the research work performed in parallel with construction have provided a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The experimental results of the first tracer test with sorbing radioactive tracers have been obtained. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. The manufacturing of the CHEMLAB probe was completed during 1996, and the first experiments were started early in 1997. During 1997 three experiments on diffusion in bentonite using {sup 57}Co, {sup 114}Cs,{sup 85}Sr, {sup 99}Tc, and {sup 131}I were conducted. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. The characterization of the rock mass in the area of the prototype repository is in progress. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition will be made in a new drift. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The

  17. Aespoe Hard Rock Laboratory. Annual report 1997

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The surface and borehole investigations and the research work performed in parallel with construction have provided a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The experimental results of the first tracer test with sorbing radioactive tracers have been obtained. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. The manufacturing of the CHEMLAB probe was completed during 1996, and the first experiments were started early in 1997. During 1997 three experiments on diffusion in bentonite using 57Co, 114Cs,85Sr, 99Tc, and 131I were conducted. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. The characterization of the rock mass in the area of the prototype repository is in progress. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition will be made in a new drift. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The Retrieval Test is aiming at

  18. Aespoe Hard Rock Laboratory Annual Report 1999

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  19. Magnetic viscosity studies in hard magnetic materials

    International Nuclear Information System (INIS)

    The magnetic viscosity behavior has been studied in several hard magnets with different magnetization reversal mechanisms including barium ferrite powders, Cu-Mn-Al, ferrite magnets, Nd-Fe-B, and SmCo5, Sm2(Co,Fe,Cu,Zr)17. The measurements were made with a vibrating sample magnetometer for times up to 60 s and a SQUID magnetometer for longer times in the range of 60--2300 s. For most of the samples the magnetization was found to vary logarithmically with time. The field and temperature dependence of the magnetic viscosity coefficient S was studied. Here, S was found to vary with the applied field and it usually peaked around the coercive field Hc. The measured values of Smax at 10 K range from 0.004 to 1.853 emu/g for Cu-Mn-Al and Sm2(Co,Fe,Cu,Zr)17, respectively. The magnetic viscosity coefficient was used together with the magnetic susceptibility to determine the activation volume

  20. The smallest hard X-ray flare?

    Science.gov (United States)

    Glesener, Lindsay; Krucker, Sam; Hannah, Iain; Smith, David M.; Grefenstette, Brian; Marsh, Andrew; Hudson, Hugh S.; White, Stephen M.; Chen, Bin

    2016-05-01

    We report a NuSTAR observation of a small solar flare on 2015 September 1, estimated to be on the order of a GOES class A.05 flare in brightness. This flare is fainter than any hard X-ray (HXR) flares in the existing literature, and with a peak rate of only ∼5 counts s‑1 detector‑1 observed by RHESSI, is effectively the smallest that can just barely be detected by the current standard (indirectly imaging) solar HXR instrumentation, though we expect that smaller flares will continue to be discovered as instrumental and observational techniques progress. The flare occurred during a solar observation by the highly sensitive NuSTAR astrophysical HXR spacecraft, which used its direct focusing optics to produce detailed flare spectra and images. The flare exhibits properties commonly observed in larger flares, including a fast rise and more gradual decay, and similar spatial dimensions to the RHESSI microflares. We will discuss the presence of non-thermal (flare-accelerated) electrons during the impulsive phase. The flare is small in emission measure, temperature, and energy, though not in physical dimensions. Its presence is an indication that flares do indeed scale down to smaller energies and retain what we customarily think of as “flarelike” properties.

  1. Hard X-ray Variability of AGN

    CERN Document Server

    Beckmann, V; Courvoisier, T J -L; Gehrels, N; Soldi, S; Tüller, J; Wendt, G

    2007-01-01

    Aims: Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X-ray range above 20 keV. Methods: The first 9 months of the Swift/BAT all-sky survey are used to study the 14 - 195 keV variability of the 44 brightest AGN. The sources have been selected due to their detection significance of >10 sigma. We tested the variability using a maximum likelihood estimator and by analysing the structure function. Results: Probing different time scales, it appears that the absorbed AGN are more variable than the unabsorbed ones. The same applies for the comparison of Seyfert 2 and Seyfert 1 objects. As expected the blazars show stronger variability. 15% of the non-blazar AGN show variability of >20% compared to the average flux on time scales of 20 days, and 30% show at least 10% flux variation. All the non-blazar AGN which show strong variability are low-luminosity objects with L(14-195 keV) < 1E44 erg/sec. Conclusions: Concer...

  2. Radiation hardness of CMS pixel barrel modules

    CERN Document Server

    Rohe, T; Erdmann, W; Kästli, H C; Khalatyan, S; Meier, B; Radicci, V; Sibille, J

    2010-01-01

    Pixel detectors are used in the innermost part of the multi purpose experiments at LHC and are therefore exposed to the highest fluences of ionising radiation, which in this part of the detectors consists mainly of charged pions. The radiation hardness of all detector components has thoroughly been tested up to the fluences expected at the LHC. In case of an LHC upgrade, the fluence will be much higher and it is not yet clear how long the present pixel modules will stay operative in such a harsh environment. The aim of this study was to establish such a limit as a benchmark for other possible detector concepts considered for the upgrade. As the sensors and the readout chip are the parts most sensitive to radiation damage, samples consisting of a small pixel sensor bump-bonded to a CMS-readout chip (PSI46V2.1) have been irradiated with positive 200 MeV pions at PSI up to 6E14 Neq and with 21 GeV protons at CERN up to 5E15 Neq. After irradiation the response of the system to beta particles from a Sr-90 source w...

  3. Computational Modeling Develops Ultra-Hard Steel

    Science.gov (United States)

    2007-01-01

    Glenn Research Center's Mechanical Components Branch developed a spiral bevel or face gear test rig for testing thermal behavior, surface fatigue, strain, vibration, and noise; a full-scale, 500-horsepower helicopter main-rotor transmission testing stand; a gear rig that allows fundamental studies of the dynamic behavior of gear systems and gear noise; and a high-speed helical gear test for analyzing thermal behavior for rotorcraft. The test rig provides accelerated fatigue life testing for standard spur gears at speeds of up to 10,000 rotations per minute. The test rig enables engineers to investigate the effects of materials, heat treat, shot peen, lubricants, and other factors on the gear's performance. QuesTek Innovations LLC, based in Evanston, Illinois, recently developed a carburized, martensitic gear steel with an ultra-hard case using its computational design methodology, but needed to verify surface fatigue, lifecycle performance, and overall reliability. The Battelle Memorial Institute introduced the company to researchers at Glenn's Mechanical Components Branch and facilitated a partnership allowing researchers at the NASA Center to conduct spur gear fatigue testing for the company. Testing revealed that QuesTek's gear steel outperforms the current state-of-the-art alloys used for aviation gears in contact fatigue by almost 300 percent. With the confidence and credibility provided by the NASA testing, QuesTek is commercializing two new steel alloys. Uses for this new class of steel are limitless in areas that demand exceptional strength for high throughput applications.

  4. Aespoe Hard Rock Laboratory. Annual Report 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. The work performed at Aespoe HRL during 2006 is in this report described in six chapters: Geo-science - experiments, analysis and modelling to increase the knowledge of the surrounding rock; Natural barriers - experiments, analysis and modelling to increase the knowledge of the repository barriers under natural conditions; Engineered barriers - demonstration of technology for and function of important engineered parts of the repository barrier system; Aespoe facility - operation, maintenance, data management, monitoring, public relations etc; Environmental research; and finally, International co-operation.

  5. On Problems as Hard as CNFSAT

    CERN Document Server

    Cygan, Marek; Lokshtanov, Daniel; Marx, Daniel; Nederlof, Jesper; Okamoto, Yoshio; Paturi, Ramamohan; Saurabh, Saket; Wahlstrom, Magnus

    2011-01-01

    Exact exponential time algorithms for NP-hard problems have thrived over the last decade. Non-trivial exponential time algorithms have been found for a myriad of problems, including Graph Coloring, Hamiltonian Path, Dominating Set and 3-CNF-SAT, that is, satisfiability of 3-CNF formulas. For some basic problems, however, there has been no progress over their trivial solution. For others, non-trivial solutions have been found, but improving these algorithms further seems to be out of reach. The CNF-SAT problem is the canonical example of a problem for which the brute force 2^n * poly(n) time algorithm remains the best known. The assumption that k-CNF-SAT requires 2^n time in the worst case when k grows to infinity is known as the strong exponential time hypothesis (SETH) of Impagliazzo and Paturi. In this paper we reveal connections between well-studied problems, and show that improving over the currently best known algorithms for several of them would violate SETH. Specifically, we show that for every epsilon...

  6. Wear of ceramic tools in hard machining

    Directory of Open Access Journals (Sweden)

    W. Grzesik

    2008-02-01

    Full Text Available Purpose: The principle purpose of this investigation is to recognize the wear phenomenon of the mixed ceramic tips against 60 HRC alloy steel specimens in dry and hard turning operations. This knowledge allows optimal machining chains to be planned by the manufacturing engineers.Design/methodology/approach: Light optical microscopy (LOM, scanning electron microscopy (SEM, BSE technique and X-ray diffraction analysis (XRM were applied for observations of worn tool surfaces, wear products and the distinction of wear mechanisms occurring.Findings: It was found that wear mechanisms observed in the machining tests involve abrasion, fracture, plastic flow, material transfer and tribochemical effects which appear depending on the mechanical and thermal conditions generated on the wear zones.Research limitations/implications: Investigations were performed under varying feed rate, constant cutting speed of 100 m/min and small depth of cut of 0.2 mm to perform finishing cuts.Practical implications: In this study both microscopic and microstructural aspects of ceramic tool wear were taken into consideration. Moreover, the development of the crater and flank wear and the associated wear mechanisms were identified.Originality/value: In particular, two types of transfer layer formation with different morphologies occurring at the rake-chip interface are distinguished.

  7. Sublittoral hard substrate communities off Helgoland

    Science.gov (United States)

    de Kluijver, M. J.

    1991-09-01

    In the Helgoland region eight sublittoral hard substrate communities occur. These communities were stationary in time during the years 1987 1989. The major governing parameters are the available amount of daylight and the degree of exposure to water movement. In the photic zone, three communities are met with, one of which is widespread and appears to be independent of the exposure to water movement. Under exposed conditions, at the lower border of the photic zone, a second community is observed. A third community is established on erosive muschelkalk substrates. In the aphotic zone also, three communities are found. The distribution of these communities is related to the rate of water movement. One community is divided into three variants, with different preferences regarding the angle of inclination and nature of the substrates. In the artificially constructed harbours, where sedimentation exceeds erosion, two different communities have settled. In the community under moderately sheltered conditions many species are found which also occur in the natural photic zone. Under extremely sheltered conditions a group of species has become dominant which is very rare in the Helgoland region outside the quay-walls but which has been described as being characteristic for sheltered localities elsewhere.

  8. Hard Transparent Arrays for Polymer Pen Lithography.

    Science.gov (United States)

    Hedrick, James L; Brown, Keith A; Kluender, Edward J; Cabezas, Maria D; Chen, Peng-Cheng; Mirkin, Chad A

    2016-03-22

    Patterning nanoscale features across macroscopic areas is challenging due to the vast range of length scales that must be addressed. With polymer pen lithography, arrays of thousands of elastomeric pyramidal pens can be used to write features across centimeter-scales, but deformation of the soft pens limits resolution and minimum feature pitch, especially with polymeric inks. Here, we show that by coating polymer pen arrays with a ∼175 nm silica layer, the resulting hard transparent arrays exhibit a force-independent contact area that improves their patterning capability by reducing the minimum feature size (∼40 nm), minimum feature pitch (pyramid pen array. Furthermore, a new method is demonstrated for patterning macroscopic feature size gradients that vary in feature diameter by a factor of 4. Ultimately, this form of polymer pen lithography allows for patterning with the resolution of dip-pen nanolithography across centimeter scales using simple and inexpensive pen arrays. The high resolution and density afforded by this technique position it as a broad-based discovery tool for the field of nanocombinatorics. PMID:26928012

  9. Matrix Recipes for Hard Thresholding Methods

    CERN Document Server

    Kyrillidis, Anastasios

    2012-01-01

    Given a set of possibly corrupted and incomplete linear measurements, we leverage low-dimensional models to best explain the data for provable solution quality in inversion. A non-exhaustive list of examples includes sparse vector and low-rank matrix approximation. Most of the well-known low dimensional models are inherently non-convex. However, recent approaches prefer convex surrogates that "relax" the problem in order to establish solution uniqueness and stability. In this paper, we tackle the linear inverse problems revolving around low-rank matrices by preserving their non-convex structure. To this end, we present and analyze a new set of sparse and low-rank recovery algorithms within the class of hard thresholding methods. We provide strategies on how to set up these algorithms via basic "ingredients" for different configurations to achieve complexity vs. accuracy tradeoffs. Moreover, we propose acceleration schemes by utilizing memory-based techniques and randomized, $\\epsilon$-approximate, low-rank pr...

  10. Statistical Physics of Hard Optimization Problems

    CERN Document Server

    Zdeborová, Lenka

    2008-01-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the NP-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this thesis is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied co...

  11. Aespoe Hard Rock Laboratory Annual report 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework.

  12. Aespoe Hard Rock Laboratory Annual report 2003

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework

  13. Implementing QML for radiation hardness assurance

    Science.gov (United States)

    Winokur, P. S.; Sexton, F. W.; Fleetwood, D. M.; Terry, M. D.; Shaneyfelt, M. R.

    1990-12-01

    The US government has proposed a qualified manufacturers list (QML) methodology to qualify integrated circuits for high reliability and radiation hardness. An approach to implementing QML for single-event upset (SEU) immunity on 16k SRAMs that involves relating values of feedback resistance to system error rates is demonstrated. It is seen that the process capability indices, Cp and Cpk, for the manufacture of 400-k-ohm feedback resistors required to provide SEU tolerance do not conform to 6 sigma quality standards. For total-dose, interface trap charge, Delta Vit, shifts measured on transistors are correlated with circuit response in the space environment. Statistical process control (SPC) is illustrated for Delta Vit, and violations of SPC rules are interpreted in terms of continuous improvement. Design validation for SEU and quality conformance inspections for total-dose are identified as major obstacles to cost-effective QML implementation. Techniques and tools that will help QML provide real cost savings are identified as physical models, 3-D device-plus-circuit codes, and improved design simulators.

  14. Aespoe Hard Rock Laboratory Annual Report 1994

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory is being constructed as part of the preparations for the deep geological repository of spent nuclear fuel in Sweden. The annual report 1994 contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of detailed investigation methodology which is applied during tunnel construction. Construction of the facility and detailed characterization of the bedrock are performed in parallel. Excavation of the main access tunnel was completed during 1994 and at the end of the year only minor excavation work remained. The last 400 m of the main tunnel, which has a total length of 3600 m, was excavated by a 5 m diameter boring machine. The tunnel reaches a depth of 450 m below ground. Preparations for the operating phase have started and detailed plans have been prepared for several experiments. Nine organizations, including SKB, from eight countries are now participating in the work at the laboratory. 50 refs, 28 figs

  15. Distributed Verification and Hardness of Distributed Approximation

    CERN Document Server

    Sarma, Atish Das; Kor, Liah; Korman, Amos; Nanongkai, Danupon; Pandurangan, Gopal; Peleg, David; Wattenhofer, Roger

    2010-01-01

    We study the {\\em verification} problem in distributed networks, stated as follows. Let $H$ be a subgraph of a network $G$ where each vertex of $G$ knows which edges incident on it are in $H$. We would like to verify whether $H$ has some properties, e.g., if it is a tree or if it is connected. We would like to perform this verification in a decentralized fashion via a distributed algorithm. The time complexity of verification is measured as the number of rounds of distributed communication. In this paper we initiate a systematic study of distributed verification, and give almost tight lower bounds on the running time of distributed verification algorithms for many fundamental problems such as connectivity, spanning connected subgraph, and $s-t$ cut verification. We then show applications of these results in deriving strong unconditional time lower bounds on the {\\em hardness of distributed approximation} for many classical optimization problems including minimum spanning tree, shortest paths, and minimum cut....

  16. The New Hard X-ray Mission

    CERN Document Server

    Tagliaferri, G; Argan, A; Bellazzini, R; Catalano, O; Costa, E; Cusumano, G; Fiore, F; Fiorini, C; Malaguti, G; Matt, G; Mereghetti, S; Micela, G; Perola, G; Villa, G

    2010-01-01

    The Italian New Hard X-ray Mission (NHXM) has been designed to provide a real breakthrough on a number of hot astrophysical issues that includes: black holes census, the physics of accretion, the particle acceleration mechanisms, the effects of radiative transfer in highly magnetized plasmas and strong gravitational fields. NHXM is an evolution of the HEXIT-Sat concept and it combines fine imaging capability up to 80 keV, today available only at E<10 keV, with sensitive photoelectric imaging polarimetry. It consists of four identical mirrors, with a 10 m focal length, achieved after launch by means of a deployable structure. Three of the four telescopes will have at their focus identical spectral-imaging cameras, while X-ray imaging polarimetric cameras will be placed at the focus of the fourth. In order to ensure a low and stable background, NHXM will be placed in a low Earth equatorial orbit. In this paper we provide an overall description of this mission that is currently in phase B.

  17. Aespoe Hard Rock Laboratory. Annual Report 2006

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. The work performed at Aespoe HRL during 2006 is in this report described in six chapters: Geo-science - experiments, analysis and modelling to increase the knowledge of the surrounding rock; Natural barriers - experiments, analysis and modelling to increase the knowledge of the repository barriers under natural conditions; Engineered barriers - demonstration of technology for and function of important engineered parts of the repository barrier system; Aespoe facility - operation, maintenance, data management, monitoring, public relations etc; Environmental research; and finally, International co-operation

  18. The phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids

    Science.gov (United States)

    Oyarzún, Bernardo; van Westen, Thijs; Vlugt, Thijs J. H.

    2013-05-01

    The liquid crystal phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids are studied by constant pressure Monte Carlo simulations. An extensive study on the phase behavior of linear fluids with a length of 7, 8, 9, 10, 11, 12, 13, 14, 15, and 20 beads is carried out. The phase behavior of partially flexible fluids with a total length of 8, 10, 14, and 15 beads and with different lengths for the linear part is also determined. A precise description of the reduced pressure and of the packing fraction change at the isotropic-nematic coexistence was achieved by performing long simulation runs. For linear fluids, a maximum in the isotropic to nematic packing fraction change is observed for a chain length of 15 beads. The infinite dilution solubility of hard spheres in linear and partially flexible hard-sphere chain fluids is calculated by the Widom test-particle insertion method. To identify the effect of chain connectivity and molecular anisotropy on free volume, solubility is expressed relative to that of hard spheres in a hard sphere fluid at same packing fraction as relative Henry's law constants. A linear relationship between relative Henry's law constants and packing fraction is observed for all linear fluids. Furthermore, this linearity is independent of liquid crystal ordering and seems to be independent of chain length for linear chains of 10 beads and longer. The same linear relationship was observed for the solubility of hard spheres in nematic forming partially flexible fluids for packing fractions up to a value slightly higher than the nematic packing fraction at the isotropic-nematic coexistence. At higher packing fractions, the small flexibility of these fluids seems to improve solubility in comparison with the linear fluids.

  19. Does water hardness have preventive effect on cardiovascular disease?

    Directory of Open Access Journals (Sweden)

    Mitra Momeni

    2014-01-01

    Conclusions: Our study suggests favorable protective effects of water hardness, mainly water magnesium content, on CVDs. Water hardness, as well as calcium and magnesium content of drinking water may have a protective role against CVDs. Further experimental studies are necessary to determine the underlying mechanisms and longitudinal studies are required to study the clinical impacts of the current findings.

  20. Absolute electronegativity and hardness correlated with molecular orbital theory

    OpenAIRE

    Pearson, Ralph G.

    1986-01-01

    The concepts of absolute electronegativity, χ, and absolute hardness, η, are incorporated into molecular orbital theory. A graphic and concise definition of hardness is given as twice the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital. Useful correlations can now be made between chemical behavior, visible-UV absorption spectra, optical polarizability, ionization potentials, and electron affinities.

  1. Phase behavior of hard colloidal platelets using free energy calculations

    NARCIS (Netherlands)

    Marechal, M.A.T.; Cuetos, A.; Martínez-Haya, B.; Dijkstra, M.

    2011-01-01

    We investigate the phase behavior of a model for colloidal hard platelets and rigid discotic molecules: oblate hard spherocylinders (OHSC). We perform free energy calculations using Monte Carlo simulations to map out the phase diagram as a function of the aspect ratio L/D of the particles. The phase

  2. String/Gauge Duality and Soft-Hard Pomerons

    International Nuclear Information System (INIS)

    We provide a brief review for the motivation of Maldacena duality conjecture, leading to the calculation for the glueball spectrum and the Pomeron intercept in the strong coupling limit. We next turns to the question of hard scattering. Using Maldacena's gauge/string duality, a unified description is provided for both the soft and the hard Pomeron in the strong coupling limit. (author)

  3. Thermodynamic signature of the dynamic glass transition in hard spheres

    NARCIS (Netherlands)

    Hermes, M; Dijkstra, M.

    2010-01-01

    We use extensive event-driven molecular dynamics simulations to study the thermodynamic, structural and dynamic properties of hard-sphere glasses. We determine the equation of state of the metastable fluid branch for hard spheres with a size polydispersity of 10%. Our results show a clear jump in th

  4. Beetle A radiation hard readout chip for the LHCb experiment

    CERN Document Server

    Agari, M; Bauer, C; Baumeister, D; Van Beuzekom, M G; Feuerstack-Raible, M; Harnew, N; Hofmann, W; Jans, E; Klous, S; Knöpfle, K T; Löchner, S; Schmelling, M; Sexauer, E; Smale, N J; Trunk, U; Verkooijen, H

    2004-01-01

    A new radiation hard pipelined readout chip is being developed for the LHCb-experiment. Appropriate design measures have been taken to ensure the radiation hardness against total ionising dose effects in excess of 45 Mrad, as well as radiation effects induced by single particles.

  5. Beetle - a radiation hard readout chip for the LHCb experiment

    Energy Technology Data Exchange (ETDEWEB)

    Agari, M.; Bakel, N. van; Bauer, C.; Baumeister, D. E-mail: baumeis@kip.uni-heidelberg.de; Beuzekom, M. van; Feuerstack-Raible, M.; Harnew, N.; Hofmann, W.; Jans, E.; Klous, S.; Knoepfle, K.T.; Loechner, S.; Schmelling, M.; Sexauer, E.; Smale, N.; Trunk, U.; Verkooijen, H

    2004-02-01

    A new radiation hard pipelined readout chip is being developed for the LHCb-experiment. Appropriate design measures have been taken to ensure the radiation hardness against total ionising dose effects in excess of 45 Mrad, as well as radiation effects induced by single particles.

  6. Beetle - a radiation hard readout chip for the LHCb experiment

    International Nuclear Information System (INIS)

    A new radiation hard pipelined readout chip is being developed for the LHCb-experiment. Appropriate design measures have been taken to ensure the radiation hardness against total ionising dose effects in excess of 45 Mrad, as well as radiation effects induced by single particles

  7. AMORPHOUS ALLOY SURFACE COATINGS FOR HARD CHROMIUM REPLACEMENT - PHASE I

    Science.gov (United States)

    Hard chromium coatings (0.25 to10 mil thick) are used extensively for imparting wear and erosion resistance to components in both industrial and military applications. The most common means of depositing hard chromium has been through the use of chromic acid baths containing ...

  8. Disappearance of diabetic macular hard exudates after hemodialysis introduction.

    Directory of Open Access Journals (Sweden)

    Matsuo,Toshihiko

    2006-06-01

    Full Text Available

    We report herein the disappearance of macular hard exudates after the introduction of hemodialysis in diabetic patients. A 62-year-old woman and a 52-year-old man with diabetes mellitus showed hard exudates in the macula of the left eyes. Both patients had previously undergone panretinal photocoagulation in both eyes. During the follow-up, hemodialysis was introduced for deteriorating chronic renal failure caused by diabetic nephropathy. Half a year later, macular hard exudates in the left eyes disappeared dramatically in both patients, but the visual acuity remained the same. No additional laser treatment was done during the observation period. Hemodialysis is considered to have accelerated the resolution of macular hard exudates in both patients. The deposition of macular hard exudates in diabetic patients is due in part to concurrent poor renal function.

  9. Aespoe Hard Rock Laboratory. Annual report 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

  10. Aespoe Hard Rock Laboratory. Annual report 1998

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

  11. Radiation hardness of CMS pixel barrel modules

    Science.gov (United States)

    Rohe, T.; Bean, A.; Erdmann, W.; Kästli, H.-C.; Khalatyan, S.; Meier, B.; Radicci, V.; Sibille, J.

    2010-12-01

    Pixel detectors are used in the innermost part of the multi purpose experiments at the LHC and are therefore exposed to the highest fluences of ionising radiation, which in this part of the detectors consists mainly of charged pions. The radiation hardness of all detector components has been thoroughly tested up to the fluences expected at the LHC. In case of an LHC upgrade, the fluence will be much higher and it is not yet clear how long the present pixel modules will stay operative in such a harsh environment. The aim of this study was to establish such a limit as a benchmark for other possible detector concepts considered for the upgrade. As the sensors and the readout chip are the parts most sensitive to radiation damage, samples consisting of a small pixel sensor bump-bonded to a CMS-readout chip (PSI46V2.1) have been irradiated with positive 200 MeV pions at PSI up to 6×1014 neq/cm2 and with 21 GeV protons at CERN up to 5×1015 neq/cm2. After irradiation the response of the system to beta particles from a 90Sr source was measured to characterise the charge collection efficiency of the sensor. Radiation induced changes in the readout chip were also measured. The results show that the present pixel modules can be expected to be still operational after a fluence of 2.8×1015 neq/cm2. Samples irradiated up to 5×1015 neq/cm2 still see the beta particles. However, further tests are needed to confirm whether a stable operation with high particle detection efficiency is possible after such a high fluence.

  12. Reliability of hard plastic clad silica fibers

    Science.gov (United States)

    Skutnik, Bolesh J.; Spaniol, Stefan

    2006-04-01

    New formulations of cladding materials have become available in recent times for Hard Plastic Clad Silica (HPCS) fibers, Initial data showed gains in some properties, particularly dynamic strength, especially for high numerical aperture (NA) fibers. A systematic study has been undertaken to determine the full strength and fatigue behavior of these HPCS fibers and to make comparisons to earlier HPCS fibers. Preliminary results, now confirmed, has shown improved median dynamic strength and higher Weibull slope. Full results are presented below including fatigue behavior and optical properties. These fibers have many applications and benefits in the high power delivery and medical laser uses as highlighted below. High power diode laser systems with their laser diode bars and arrays not only require special fibers to couple directly to the diode emitters, but also require special fibers to couple from the laser to application sites. These latter power delivery fibers are much larger than the internal fibers but still must be flexible, and have not only good strength but also good fatigue behavior. This particularly important industrial systems using robotic arms to apply the high power laser energy at a treatment site. The optical properties of HPCS fibers are well suited for the needs of the delivery of high power from diode laser bars and arrays to an application site. Benefits of strong median dynamic strengths and tighter flaw distributions in such cases will be discussed. Many medical applications, especially endoscopic ones, can benefit from the use of highly flexible, high NA, cost effective, HPCS optical fibers. Benefits of high strength and good fatigue behavior for such fibers in endoscopic procedures, including laser surgery, are discussed briefly including implications for mechanical reliability in medical and industrial settings.

  13. Hardness ratios of different neutron spectra.

    Science.gov (United States)

    Tommasino, L; Tripathy, S P

    2004-01-01

    Extensive data have been gathered in the past on the response of different detectors, based on the registration of neutron-induced fissions in bismuth, gold, tantalum and thorium by the spark-replica counter and the thin film breakdown counter. These detectors make it possible to exploit the excellent characteristics of the fission reactions for the measurements of high-energy neutrons. Most of the investigations have been carried out at the quasi-monoenergetic neutron beam facility at The Svedberg Laboratory-TSL of the Uppsala University in cooperation with the Khlopin Radium Institute (KRI). The responses of different fission detectors in the neutron energy range 35-180 MeV have been evaluated: a region where the predictive power of available nuclear reaction models and codes is not reliable yet. For neutron energy >200 MeV, the fission-detector responses have been derived from the data of the proton fission cross sections. By using the ratio of the responses of these detectors, a simple and accurate way to evaluate the spectrum hardness can be obtained, thus providing a tool to obtain spectral information needed for neutron dosimetry without the need to know the entire spectrum. Extensive data have been already obtained for the high-energy neutron spectrum from the CERN concrete facility. In the present paper, the measured values of the response ratios for different fissile detectors exposed at the CERN facility are compared with those calculated for the spectra from the same facility and from different altitudes in the atmosphere, respectively. PMID:15353650

  14. WALNUT: NOT A HARD NUT TO CRACK

    Directory of Open Access Journals (Sweden)

    Khanna Deepa

    2011-05-01

    Full Text Available Walnuts grow on large trees, known for their beauty, timber and tasty edible nuts. There are many varieties of walnuts that vary in hardiness, nut size and thickness of the nut shell. When it comes to their health benefits, Walnuts definitely are not hard nuts to crack. They contain free radical scavenging compounds like ellagic acid, juglone and certain phytosterols that support the immune system and appear to have anti-cancer properties. Walnuts have higher contents of polyunsaturated fatty acids including α-Linolenic acid, than do other nuts which may give walnuts additional anti-atherogenic and cosmetic value. It was found in clinical trials that walnut consumption in the amount of two to three servings per day consistently decreased total cholesterol and LDL cholesterol. Linolenic acid and Linoleic acids present abundantly in walnuts are crucial for maintaining skin functions such as regulation of transepidermal water loss and anti- inflammatory action. The beneficial action of walnut oil on skin is known for centuries and is widely used in cosmetic industry. The walnut oil is a component of dry skin creams, anti-wrinkle and anti-ageing products as it possesses moisturizing property as well as free radical scavenging capacity. Besides, they also exhibit anti-microbial, anti-diabetic, anti-stress, anti-ageing and Hepatoprotective activities. “Walnuts are better than cookies, french fries or potato chips, when you need a snack” as they provide rich nutrients. In the light of above, we thought it worthwhile to compile an up-to-date review article on Walnuts covering its synonyms, phytoconstituents, phytopharmacology and medicinal uses.

  15. Orientational Ordering and Phase Behaviour of Binary Mixtures of Hard Spheres and Hard Spherocylinders.

    Czech Academy of Sciences Publication Activity Database

    Wu, L.; Malijevský, Alexandr; Jackson, G.; Muller, E.A.; Avendano, C.

    2015-01-01

    Roč. 143, č. 4 (2015), s. 044906. ISSN 0021-9606 R&D Projects: GA ČR(CZ) GA13-02938S Grant ostatní: EPSRC(GB) GR/T17595; EPSRC(GB) GR/N35991; EPSRC(GB) EP/E016340; EPSRC(GB) EP/J014958; JREI(GB) GR/M94426 Institutional support: RVO:67985858 Keywords : phase behaviour * liquid crystals * hard spheres Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.952, year: 2014

  16. Depletion effects in smectic phases of hard-rod-hard-sphere mixtures.

    Science.gov (United States)

    Martínez-Ratón, Y; Cinacchi, G; Velasco, E; Mederos, L

    2006-10-01

    It is known that when hard spheres are added to a pure system of hard rods the stability of the smectic phase may be greatly enhanced, and that this effect can be rationalised in terms of depletion forces. In the present paper we first study the effect of orientational order on depletion forces in this particular binary system, comparing our results with those obtained adopting the usual approximation of considering the rods parallel and their orientations frozen. We consider mixtures with rods of different aspect ratios and spheres of different diameters, and we treat them within Onsager theory. Our results indicate that depletion effects, and consequently smectic stability, decrease significantly as a result of orientational disorder in the smectic phase when compared with corresponding data based on the frozen-orientation approximation. These results are discussed in terms of the tau parameter, which has been proposed as a convenient measure of depletion strength. We present closed expressions for tau, and show that it is intimately connected with the depletion potential. We then analyse the effect of particle geometry by comparing results pertaining to systems of parallel rods of different shapes (spherocylinders, cylinders and parallelepipeds). We finally provide results based on the Zwanzig approximation of a fundamental-measure density-functional theory applied to mixtures of parallelepipeds and cubes of different sizes. In this case, we show that the tau parameter exhibits a linear asymptotic behaviour in the limit of large values of the hard-rod aspect ratio, in conformity with Onsager theory, as well as in the limit of large values of the ratio of rod breadth to cube side length, d, in contrast to Onsager approximation, which predicts tau approximately d (3). Based on both this result and the Percus-Yevick approximation for the direct correlation function for a hard-sphere binary mixture in the same limit of infinite asymmetry, we speculate that, for

  17. Starch granule size distribution of hard red winter and hard red spring wheat: Its effects on mixing and breadmaking quality.

    Science.gov (United States)

    Starch was isolated from 98 hard red winter (HRW) wheat and 99 hard red spring (HRS) wheat. Granule size/volume distributions of the isolated starches were analyzed using a laser diffraction particle size analyzer. There were significant differences in the size distribution between HRW and HRS whe...

  18. Hard-sphere fluids inside spherical, hard pores. Grand canonical ensemble Monte Carlo calculations and integral equation approximations

    DEFF Research Database (Denmark)

    Sloth, Peter

    1990-01-01

    Density profiles and partition coefficients are obtained for hard-sphere fluids inside hard, spherical pores of different sizes by grand canonical ensemble Monte Carlo calculations. The Monte Carlo results are compared to the results obtained by application of different kinds of integral equation...

  19. Exchange-spring mechanism of soft and hard ferrite nanocomposites

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Exchange-spring behaviour of soft and hard ferrites was studied. • XRD patterns indicated soft and hard ferrites as fcc and hcp structure. • Hysteresis loops indicate wide difference in coercivity of soft and hard phases. • Nanocomposites produced convex hysteresis loop characteristic of single-phase. - Abstract: The paper reports exchange-spring soft and hard ferrite nanocomposites synthesized by chemical co-precipitation with or without the application of ultrasonic vibration. The composites contained BaFe12O19 as the hard phase and CoFe2O4/MgFe2O4 as the soft phase. X-ray diffraction patterns of the samples in the optimum calcined condition indicated the presence of soft ferrites as face-centred cubic (fcc) and hard ferrites as hexagonal close packed (hcp) structure respectively. Temperature dependence of magnetization in the range of 20–700 °C demonstrated distinct presence of soft and hard ferrites as magnetic phases which are characterized by wide difference in magnetic anisotropy and coercivity. Exchange-spring mechanism led these nanocomposite systems to exchange-coupled, which ultimately produced convex hysteresis loops characteristic of a single-phase permanent magnet. Fairly high value of coercivity and maximum energy product were observed for the samples in the optimum calcined conditions with a maximum applied field of 1600 kA/m (2 T)

  20. Agnostic Learning of Monomials by Halfspaces is Hard

    CERN Document Server

    Feldman, Vitaly; Raghavendra, Prasad; Wu, Yi

    2010-01-01

    We prove the following strong hardness result for learning: Given a distribution of labeled examples from the hypercube such that there exists a monomial consistent with $(1-\\eps)$ of the examples, it is NP-hard to find a halfspace that is correct on $(1/2+\\eps)$ of the examples, for arbitrary constants $\\eps > 0$. In learning theory terms, weak agnostic learning of monomials is hard, even if one is allowed to output a hypothesis from the much bigger concept class of halfspaces. This hardness result subsumes a long line of previous results, including two recent hardness results for the proper learning of monomials and halfspaces. As an immediate corollary of our result we show that weak agnostic learning of decision lists is NP-hard. Our techniques are quite different from previous hardness proofs for learning. We define distributions on positive and negative examples for monomials whose first few moments match. We use the invariance principle to argue that regular halfspaces (all of whose coefficients have s...

  1. TURKISH HARD COAL AGENCY ECONOMIC EFFECT OF ZONGULDAK

    Directory of Open Access Journals (Sweden)

    Mesut ELİBÜYÜK

    2015-04-01

    Full Text Available Turkish Hard Coal Agency -the only institution engaged in coal extractionhas made great contributions in the economic sense, in the western Black Sea region or even the entire Black Sea region. That institution Turkish Hard Coal Agency, particularly in terms of the development of the province of Zonguldak has been a decisive influence. The extraction of coal in the institution goes through in a challenging process. The businesses, factories, the location of lavuars, wells of Turkish Hard Coal Agency have appointed both urban development areas as well as the direction of migration. Depending on Turkish Hard Coal Agency, many industries have been established in this region but the region's economy is mainly dominated by iron and steel sector. Turkish Hard Coal Agency has made some significant impacts in the other activities of the workers in the institution. The agriculture, livestock, forestry, industrial and commercial activities remain under the influence of Turkish Hard Coal Agency and these activities are being shaped by the production of Turkish Hard Coal Agency. There is also seen the largest share of public investments in mining.

  2. WATER HARDNESS AS AN IMPORTANT PARAMETER OF PH

    Directory of Open Access Journals (Sweden)

    Žigmund Tóth

    2013-02-01

    Full Text Available Quality of final product is to great extent influenced by intermediate products that are formed during beer production. In addition quality of pH is one of the most important properties that forms suitable medium for activity of enzymes complexes that have crucial influence on character of produced wort. Moreover enzymes influence the yield of production process and quality of final product as well. Quality of boiling water and especially its hardness have crucial task in terms of keeping optimal qualitative parameters. Water hardness is given by amount of salts, mainly calcium and magnesium salts. It is expressed as absolute hardness which is given by sum of temporary (carbonate and permanent (noncarbonate hardness. In our work we solved the effect of total water hardness on final pH of various intermediate products. We used different water samples and we prepared variants of total hardness by stirring of unpurified water with distilled water thus we achieved various values of hardness. For comparison we prepared several brews with regard to combinations of unpurified water and distilled water. Higher pH of boiling water was caused due to higher water alkalinity that negatively affected enzyme complex present in used malt. Presence of hydrogenphosphates in used malt had high buffering ability and pH lowering ability. Such unfavorable result could be adjust by use of various additions of acidulates that would have in great extent influence on beer final price therefore boiling water adjustment seems to be the most acceptable approach.

  3. Enhancing the hardness of Al/W nanostructured coatings.

    Science.gov (United States)

    Burgmann, F A; McCulloch, D G; Ryves, L; Lim, S H N; McKenzie, D R; Bilek, M M M

    2009-02-01

    Two-component multilayer thin films frequently show hardness enhancements at specific repeat periods above that of the constituent layers. This study of hardness enhancements in W/Al nanostructured coatings provides strong new evidence that hardness enhancements in this system arise not only from the presence of a layered structure, but also from the presence of defects introduced by changing the deposition conditions. Samples with well defined layers of W and Al were produced by sputtering to cover a wide range of periods from 10 to 200 nm. No evidence of enhanced hardness in these films was found by nanoindentation. On the other hand, samples deposited from cathodic arc sources showed strong hardness enhancement above that of pure W. However, the samples of highest hardness did not contain Al layers for much of their thickness. The hardening mechanism therefore could not be attributed to the presence of a multilayer structure. Examination of the microstructure showed that the interruptions to the W deposition caused by operation of the Al source introduced defects which acted as pinning sites for dislocations. The nanoindentation hardness data were well described using a modified Hall-Petch relation. PMID:21817290

  4. Analysis of surface hardness of artificially aged resin composites

    Directory of Open Access Journals (Sweden)

    Denise Cremonezzi Tornavoi

    2012-02-01

    Full Text Available This study evaluated the effect of artificially accelerated aging (AAA on the surface hardness of eight composite resins: Filtek Z250, Filtek Supreme, 4 Seasons, Herculite, P60, Tetric Ceram, Charisma, and Filtek Z100. Sixteen specimens were made from the test piece of each material, using an 8.0 × 2.0 mm teflon matrix. After 24 hours, eight specimens from each material were submitted to three surface hardness readings using a Shimadzu Microhardness Tester for 5 seconds at a load of 50 gf. The other eight specimens remained in the artificially accelerated aging machine for 382 hours and were submitted to the same surface hardness analysis. The means of each test specimen were submitted to the Kolmogorov-Smirnov test (p > 0.05, ANOVA and Tukey test (p < 0.05. With regard to hardness (F = 86.74, p < 0.0001 the analysis showed significant differences among the resin composite brands. But aging did not influence the hardness of any of the resin composites (F = 0.39, p = 0.53. In this study, there was interaction between the resin composite brand and the aging factors (F = 4.51, p < 0.0002. It was concluded that notwithstanding the type of resin, AAA did not influence surface hardness. However, with regard to hardness there was a significant difference among the resin brands.

  5. Specific Energy of Hard Coal Under Load

    Directory of Open Access Journals (Sweden)

    Bogusz Anna

    2015-03-01

    Full Text Available The article presents results of experimental tests of energy parameters of hard coals under loading, collected from research sites located within five main geologic structures of Upper Silesian Coal Basin (GZW - Main Trough, Main Anticline, Bytom Trough, Rybnik Trough and Chwałowice Trough. Coals from12 mines were analysed, starting with seams of group 200, through groups 400, 500, 600 and, finally, seams of group 700. Coal of each of the groups of seams underwent uniaxial compression stress of the energy parameters, in a servo-controlled testing machine MTS-810NEW, for the full range of strain of the tested coal samples. Based on the tests the dependence of different types of specific energy of longitudinal strain of coals on the value of uniaxial compression strength was determined. The dependence of the value of dissipated energy and kinetic energy of coals on the uniaxial compression strength was described with a linear function, both for coals which due to their age belong to various bed sand for various lithotypes of coal. An increase in the value of dissipated energy and in kinetic energy was observed, which was correlated with an increase in uniaxial compression strength of coal. The share of dissipated energy is dominant in the total energy of strain. Share of recoverable energy in the total energy of strain is small, independent of the compression strength of coals and is at most a few per cent high. In coals of low strength and dominant share of dissipated energy, share of recoverable energy is the biggest among the tested coals. It was shown that following an increase in compression strength the share of recoverable energy decreases, while the share of dissipated energy in the total energy increases. Further studies of specific energy of longitudinal strain of rocks in the full-range strain will be the next step inperfecting methodology of research into natural rock burst susceptibility of Carboniferous rock mass and changes in the

  6. AeSPoe HARD ROCK LABORATORY

    International Nuclear Information System (INIS)

    Aespoe Hard Rock Laboratory (AEHRL) has been constructed in virgin bedrock as part of the development of a deep geological repository for spent nuclear fuel in Sweden, the role being to provide input to the performance assessment, to test engineered barrier systems and to develop and refine full scale methods and machines for construction and operation of the real repository. The AEHRL extends down to 460 m depth with access via both ramp and shaft. Work in the laboratory has been separated into 4 different stage goals: (1) Verification of site investigation methods. (2) Development of detailed investigation methodology. (3) Testing of models for description of the barrier function of the host rock. (4) Demonstration of technology for and function of important parts of the repository system Stage goals 1 and 2 were in focus during the period 1986-95 and are now completed. Stage goal 1 concerns investigations carried out from ground surface and stage goal 2 investigations carried out underground, in this case during excavation of the ramp. The present work is focused on the two operative stage goals 3 and 4. The activities on barrier function of the host rock comprises primarily in-situ tests with tracer migration in natural fractures and migration of actinides in small samples of rock or bentonite inside a chemical laboratory probe installed in a borehole. The data collected from the tests are used for model development and verification. The demonstration of technology includes studies of engineered barriers and comprises tests of copper stability, bentonite buffer, backfill, plugging and practical development of the main disposal sequences. Up today five full scale deposition holes with buffer and canister, and one full-scale test of backfill and plugging have been installed. The prototype for the deposition machine is in operation. The work is conducted in an international environment and altogether eight organizations from seven countries besides Sweden take

  7. YOHKOH remnants: partially occulted flares in hard X-rays

    OpenAIRE

    M. Tomczak

    2009-01-01

    Flares being partially occulted by the solar limb, are the best reservoir of our knowledge about hard X-ray loop-top sources. Recently, the survey of partially occulted flares observed by the RHESSI has been published (Krucker & Lin 2008). The extensive YOHKOH database still awaits such activities. This work is an attempt to fill this gap. Among from 1286 flares in the YOHKOH Hard X-ray Telescope Flare Catalogue, for which the hard X-ray images had been enclosed, we identified 98 events that ...

  8. Broad-band hard X-ray reflectors

    DEFF Research Database (Denmark)

    Joensen, K.D.; Gorenstein, P.; Hoghoj, P.;

    1997-01-01

    Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of...... that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted....

  9. The Political Economy of the Hard-ECU Proposal

    OpenAIRE

    Bofinger, Peter

    1991-01-01

    The paper shows that the conversion from national currency bank notes to hard-ECU notes is promoted by the provision of an implicit and free currency call option. This wealth effect is caused by the devaluation-proof definition of this currency. Nevertheless, additional transactions and information costs would keep the demand for hard-ECUs very limited. Because of such externalities the market does not lead to a Pareto-efficient arrangement for the European monetary order. At best the hard-EC...

  10. Cutting capacity of PDC cutters in very hard rock

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed.Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite.The effects of the rough degree of rock surface,cutting angles,and static thrust on the cutting capacity of PDC in very hard rock were investigated and analyzed.The results show that the single mode of rotary drilling using PDC cutters is not applied for very hard rocks.

  11. Thermal histories causing low hardness and the minimum hardness requirement in a modified 9Cr1Mo steel for boiler

    International Nuclear Information System (INIS)

    In a Mod.9Cr1Mo steel widely applied to boiler components, low hardness problem related with manufacturing and fabrication processes has become a critical issue recently. In this study, hardness, microstructure, tensile and creep rupture tests have been performed using specimens experienced various thermal cycles to investigate the detailed mechanism causing low hardness values of 150 to 170 Hv and the minimum hardness requirement from a standpoint of tensile and allowable stresses. Low hardness values were mainly attributed to the formation of ferrite structure on cooling after heating at intercritical temperature just above the Ac1, 850 .deg. C. Ferrite transformation on cooling after intercritical heating occurred even at the relatively faster cooling compared to normal heating above the Ac3 since the nose of ferrite transformation in the CCT curve moved to the left due to the very low carbon content in austenite phase formed at intercritical temperature. Low hardness value of 160's Hv occurred occasionally in practical applications was observed at a cooling rate of below 0.167 deg. C/sec(10 .deg. C/min) after intercritical heating. At least 190 Hv of hardness values or more were needed to satisfy tensile properties and maximum allowable stresses specified in ASME B and PV code

  12. Perpendicular recording media for hard disk drives

    Science.gov (United States)

    Piramanayagam, S. N.

    2007-07-01

    Perpendicular recording technology has recently been introduced in hard disk drives for computer and consumer electronics applications. Although conceptualized in the late 1970s, making a product with perpendicular recording that has competing performance, reliability, and price advantage over the prevalent longitudinal recording technology has taken about three decades. One reason for the late entry of perpendicular recording is that the longitudinal recording technology was quite successful in overcoming many of its problems and in staying competitive. Other reasons are the risks, problems, and investment needed in making a successful transition to perpendicular recording technology. Iwasaki and co-workers came up with many inventions in the late 1970s, such as single-pole head, CoCr alloy media with a perpendicular anisotropy, and recording media with soft magnetic underlayers [S. Iwasaki and K. Takemura, IEEE Trans. Magn. 11, 1173 (1975); S. Iwasaki and Y. Nakamura, IEEE Trans. Magn. 14, 436 (1978); S. Iwasaki, Y. Nakamura, and K. Ouchi, IEEE Trans. Magn. 15, 1456 (1979)]. Nevertheless, the research on perpendicular recording media has been intense only in the past five years or so. The main reason for the current interest comes from the need to find an alternative technology to get away from the superparamagnetic limit faced by the longitudinal recording. Out of the several recording media materials investigated in the past, oxide based CoCrPt media have been considered a blessing. The media developed with CoCrPt-oxide or CoCrPt -SiO2 have shown much smaller grain sizes, lower noise, and larger thermal stability than the perpendicular recording media of the past, which is one of the reasons for the success of perpendicular recording. Moreover, oxide-based perpendicular media have also overtaken the current longitudinal recording media in terms of better recording performance. Several issues that were faced with the soft underlayers have also been solved by the

  13. Aespoe Hard Rock Laboratory. Annual Report 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2009 is given below. Geoscience Geoscientific research is a basic activity at Aespoe HRL. The aim of the current studies is to develop geoscientific models of the Aespoe HRL and increase the understanding of the rock mass properties as well as knowledge of applicable methods of measurement. A main task within the geoscientific field is the development of the Aespoe Site Descriptive Model (SDM) integrating information from the different fields. The main activities in the geoscientific fields have been: (1) Geology evaluation of geological mapping techniques leading to the decision to develop a SKB mapping system and finalization of the mapping of rock surfaces in the new tunnel, (2) Hydrogeology monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics finalised the field tests on thermally-induced spalling in deposition holes and evaluated the effect of counterforce in the deposition holes. Natural barriers At Aespoe HRL, experiments are

  14. Aespoe Hard Rock Laboratory. Annual Report 2008

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. The main activities in the geoscientific fields have been: (1) Geology - completion of the feasibility study concerning geological mapping techniques and mapping of rock surfaces in the new tunnel, (2) Hydrogeology - monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field tests to evaluate the counterforce needed to prevent thermally-induced spalling in deposition holes. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. A number of large-scale field experiments and supporting activities concerning Engineered barriers are carried out at Aespoe HRL. The experiments focus on different aspects of engineering technology and performance testing: The Prototype Repository is a demonstration of the integrated function of the repository and provides a full-scale reference for tests of predictive models concerning individual components as well as the complete repository system; The Long Term Test of Buffer Material (Lot-experiment) aims at validating models and hypotheses concerning physical properties in a bentonite buffer material and of related processes regarding microbiology, radionuclide transport, copper corrosion and gas transport; The objective of the project Alternative Buffer

  15. Experiments at the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    A dress rehearsal is being held in preparation for the construction of a deep repository for spent nuclear fuel at SKB's underground Hard Rock Laboratory (HRL) on Aespoe, outside Oskarshamn. Here we can test different technical solutions on a full scale and in a realistic environment. The Aespoe HRL is also used for field research. We are conducting a number of experiments here in collaboration with Swedish and international experts. In the Zedex experiment we have compared how the rock is affected around a drill-and-blast tunnel versus a bored tunnel. In a new experiment we will investigate how much the rock can take. A narrow pillar between two boreholes will be loaded to the point that the rock's ultimate strength is exceeded (Aespoe Pillar Stability Experiment). In the Demo Test we are demonstrating emplacement of the copper canisters and the surrounding bentonite in the deposition holes. In the Prototype Repository we study what long-term changes occur in the barriers under the conditions prevailing in a deep repository. Horizontal deposition: Is it possible to deposit the canisters horizontally without compromising safety? Backfill and Plug Test: The tunnels in the future deep repository for spent nuclear fuel will be filled with clay and crushed rock and then plugged. Canister Retrieval Test: If the deep repository should not perform satisfactorily for some reason, we want to be able to retrieve the spent fuel. The Lot test is intended to show how the bentonite behaves in an environment similar to that in the future deep repository. The purpose of the TBT test is to determine how the bentonite clay in the buffer is affected by high temperatures. Two-phase flow means that liberated gas in the groundwater flows separately in the fractures in the rock. This reduces the capacity of the rock to conduct water. Lasgit: By pressurizing a canister with helium, we can measure how the gas moves through the surrounding buffer. Colloid Project: Can very small particles

  16. Aespoe Hard Rock Laboratory. Annual Report 2005

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL), in the Simpevarp area in the municipality of Oskarshamn constitutes an important part of SKB's work with the design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its associated research, as well as in the development and demonstration tasks. Most of the research is focused on processes of importance for the long-term safety of a final repository for spent nuclear fuel. Demonstration addresses the performance of the engineered barriers and practical means of constructing and operating a repository for spent fuel. To meet the overall time schedule for SKB's RD and D work, the following stage goals were initially defined for the work at the Aespoe HRL: 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop, and at repository depth, test methods and models for description of groundwater flow, radionuclide migration and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important parts of the

  17. Aespoe Hard Rock Laboratory. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    The Aespoe Hard Rock Laboratory (HRL), in the Simpevarp area in the municipality of Oskarshamn constitutes an important part of SKB's work with the design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its associated research, as well as in the development and demonstration tasks. Most of the research is focused on processes of importance for the long-term safety of a final repository for spent nuclear fuel. Demonstration addresses the performance of the engineered barriers and practical means of constructing and operating a repository for spent fuel. To meet the overall time schedule for SKB's RD and D work, the following stage goals were initially defined for the work at the Aespoe HRL: 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop, and at repository depth, test methods and models for description of groundwater flow, radionuclide migration and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important

  18. Aespoe hard rock laboratory. Annual report 2000

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of the

  19. Amplitude-temperature analysis of hard rubber by torsional vibration

    Czech Academy of Sciences Publication Activity Database

    Šulc, Petr; Pešek, Luděk; Bula, Vítězslav; Cibulka, Jan; Košina, Jan

    2016-01-01

    Roč. 821, č. 2016 (2016), s. 295-302. ISSN 1660-9336 Institutional support: RVO:61388998 Keywords : hard rubber * torsion vibration * finite deformation * parameter identification Subject RIV: BI - Acoustics

  20. Rad-hard embedded computers for nuclear robotics

    International Nuclear Information System (INIS)

    For requirements of nuclear industries, it is necessary to use robots with embedded rad hard electronics and high level safety. The computer developed for french research program SYROCO is presented in this paper. (authors). 8 refs., 5 figs

  1. Inclusion of Unambiguous RE#s is NP-Hard

    OpenAIRE

    Kilpeläinen, Pekka

    2011-01-01

    We show that testing inclusion between languages represented by regular expressions with numerical occurrence indicators (RE#s) is NP-hard, even if the expressions satisfy the requirement of "unambiguity", which is required for XML Schema content model expressions.

  2. Constraint satisfaction problems with isolated solutions are hard

    International Nuclear Information System (INIS)

    We study the phase diagram and the algorithmic hardness of the random 'locked' constraint satisfaction problems, and compare them to the commonly studied 'non-locked' problems like satisfiability of Boolean formulae or graph coloring. The special property of the locked problems is that clusters of solutions are isolated points. This simplifies significantly the determination of the phase diagram, which makes the locked problems particularly appealing from the mathematical point of view. On the other hand, we show empirically that the clustered phase of these problems is extremely hard from the algorithmic point of view: the best known algorithms all fail to find solutions. Our results suggest that the easy/hard transition (for currently known algorithms) in the locked problems coincides with the clustering transition. These should thus be regarded as new benchmarks of really hard constraint satisfaction problems

  3. Study Suggests Brain Is Hard-Wired for Chronic Pain

    Science.gov (United States)

    ... News Release Tuesday, September 17, 2013 NIH-funded study suggests brain is hard-wired for chronic pain ... Apkarian, Ph.D., a senior author of the study and professor of physiology at Northwestern University Feinberg ...

  4. Scotch-Tape Mirror for Hard X-rays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The project is to build a grazing incidence mirror for hard X-rays (E>20 keV) using a “scotch-tape” design, in which a thin plastic tape with a...

  5. Extreme Temperature, Rad-Hard Power Management ASIC Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group will design a rad-hard Application Specific Integrated Circuit (ASIC) for spacecraft power management that is functional over a temperature range of...

  6. Model for magnetostrictive performance in soft/hard coupled bilayers

    International Nuclear Information System (INIS)

    A model is set up to investigate the magnetostrictive performance and spin response in soft/hard magnetostrictive coupled bilayers. Direct coupling between soft ferromagnet and hard TbFe2 at the interface is assumed. The magnetostriction results from the rotation of ferromagnetic vector and TbFe2 vectors from the easy axis driven by applied magnetic field. Dependence of magnetostriction on TbFe2 layer thickness and interfacial exchange interaction is studied. The simulated results reveal the compromise between interfacial exchange interaction and anisotropy of TbFe2 hard layer. - Highlights: • A model for magnetostrictive performance in soft/hard coupled bilayers. • Simulated magnetostriction loop and corresponding spin response. • Competition and compromise between interfacial interaction and TbFe2 anisotropy. • Dependence of saturated magnetostriction on different parameters

  7. A short review of the theory of hard exclusive processes

    CERN Document Server

    Wallon, Samuel

    2011-01-01

    We first present an introduction to the theory of hard exclusive processes. We then illustrate this theory by a few selected examples. The last part is devoted to the most recent developments in the asymptotical energy limit.

  8. Hard-real-time resource management for autonomous spacecraft

    Science.gov (United States)

    Gat, E.

    2000-01-01

    This paper describes tickets, a computational mechanism for hard-real-time autonomous resource management. Autonomous spacecraftcontrol can be considered abstractly as a computational process whose outputs are spacecraft commands.

  9. High Operating Temperature, Radiation-Hard MIM Thermophotovoltaic Converters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spire Corporation proposes to investigate InGaAs thermophotovoltaic (TPV) cells optimized for high temperature operation (~150C) and radiation hardness against the...

  10. Self-lubricating Hard Coatings for Extreme Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This program will develop low friction hard coatings for lubricating mechanical and tribological components used for exploring Mars, the Moon, asteroids, comets and...

  11. Hardness and Microstructure of Binary and Ternary Nitinol Compounds

    Science.gov (United States)

    Stanford, Malcolm K.

    2016-01-01

    The hardness and microstructure of twenty-six binary and ternary Nitinol (nickel titanium, nickel titanium hafnium, nickel titanium zirconium and nickel titanium tantalum) compounds were studied. A small (50g) ingot of each compound was produced by vacuum arc remelting. Each ingot was homogenized in vacuum for 48 hr followed by furnace cooling. Specimens from the ingots were then heat treated at 800, 900, 1000 or 1100 degree C for 2 hr followed by water quenching. The hardness and microstructure of each specimen was compared to the baseline material (55-Nitinol, 55 at.% nickel - 45 at.% titanium, after heat treatment at 900 degC). The results show that eleven of the studied compounds had higher hardness values than the baseline material. Moreover, twelve of the studied compounds had measured hardness values greater 600HV at heat treatments from 800 to 900 degree C.

  12. CAPSULE REPORT: HARD CHROME FUME SUPPRESSANTS & CONTROL TECHNOLOGIES

    Science.gov (United States)

    All existing information which includes the information extrapolated from the Hard Chrome Pollution Prevention Demonstration Project(s) and other sources derived from plating facilities and industry contacts, will be condensed and featured in this document. At least five chromium...

  13. Adaptive Lobster-Eye Hard X-Ray Telescope Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA needs for hard X-ray telescopes for starlight detection and wavefront analysis, Physical Optics Corporation (POC) proposes to develop an Adjustable...

  14. Model for magnetostrictive performance in soft/hard coupled bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Jianjun, Li, E-mail: ljj8081@gmail.com [National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150080 (China); Laboratoire de Magnétisme de Bretagne, Université de Bretagne Occidentale, 29238 Brest Cedex 3 (France); Beibei, Duan; Minglun, Li [National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150080 (China)

    2015-11-01

    A model is set up to investigate the magnetostrictive performance and spin response in soft/hard magnetostrictive coupled bilayers. Direct coupling between soft ferromagnet and hard TbFe{sub 2} at the interface is assumed. The magnetostriction results from the rotation of ferromagnetic vector and TbFe{sub 2} vectors from the easy axis driven by applied magnetic field. Dependence of magnetostriction on TbFe{sub 2} layer thickness and interfacial exchange interaction is studied. The simulated results reveal the compromise between interfacial exchange interaction and anisotropy of TbFe{sub 2} hard layer. - Highlights: • A model for magnetostrictive performance in soft/hard coupled bilayers. • Simulated magnetostriction loop and corresponding spin response. • Competition and compromise between interfacial interaction and TbFe{sub 2} anisotropy. • Dependence of saturated magnetostriction on different parameters.

  15. Development of creep curves from hot indentation hardness data

    International Nuclear Information System (INIS)

    Indentation creep is defined as time dependent motion of a hard indenter into a solid under constant load and temperature. This technique is particularly advantageous for health hazardous radioactive nuclear materials since small samples are required for this test and a large number of data could be generated on the same sample. The only requirement for evaluation of indentation hardness and creep is a metallographically polished specimen surface. Several investigators have correlated hot hardness with creep and have estimated activation energy for creep and stress exponent for steady state creep rate. The aim of the present work is to evaluate hot hardness and in turn creep behavior of U-Zr alloy fuels containing 5, 10 and 15 wt.% of Zr and fuel cladding materials namely stainless steel (type 316) and zircaloy-2

  16. Genetic Evolutionary Approach for Cutting Forces Prediction in Hard Milling

    Science.gov (United States)

    Taylan, Fatih; Kayacan, Cengiz

    2011-11-01

    Hard milling is a very common used machining procedure in the last years. Therefore the prediction of cutting forces is important. The paper deals with this prediction using genetic evolutionary programming (GEP) approach to set mathematical expression for out cutting forces. In this study, face milling was performed using DIN1.2842 (90MnCrV8) cold work tool steel, with a hardness of 61 HRC. Experimental parameters were selected using stability measurements and simulations. In the hard milling experiments, cutting force data in a total of three axes were collected. Feed direction (Fx) and tangential direction (Fy) cutting forces generated using genetic evolutionary programming were modelled. Cutting speed and feed rate values were treated as inputs in the models, and average cutting force values as output. Mathematical expressions were created to predict average Fxand Fy forces that can be generated in hard material milling.

  17. Event-driven Langevin simulations of hard spheres.

    Science.gov (United States)

    Scala, A

    2012-08-01

    The blossoming of interest in colloids and nanoparticles has given renewed impulse to the study of hard-body systems. In particular, hard spheres have become a real test system for theories and experiments. It is therefore necessary to study the complex dynamics of such systems in presence of a solvent; disregarding hydrodynamic interactions, the simplest model is the Langevin equation. Unfortunately, standard algorithms for the numerical integration of the Langevin equation require that interactions are slowly varying during an integration time step. This is not the case for hard-body systems, where there is no clear-cut distinction between the correlation time of the noise and the time scale of the interactions. Starting first from a splitting of the Fokker-Plank operator associated with the Langevin dynamics, and then from an approximation of the two-body Green's function, we introduce and test two algorithms for the simulation of the Langevin dynamics of hard spheres. PMID:23005884

  18. Hard magnetic composite materials with polymer matrix reinforced Nd-Fe-B hard magnetic particles

    International Nuclear Information System (INIS)

    Investigation results of the polymer matrix hard magnetic composite materials with particles of the powered rapid quenched Nd-Fe-B strip quenched Nd-Fe-B strip are presented at this paper. The Nd-Fe-B powder was doped (10 wt.%) with powder of iron, aluminium, CuSn10 casting copper alloy with tin, high alloy steel X2CrNiNo17-12-2 and aluminium oxide. Epoxy resin has been used as a matrix (2.5 wt.%). The pressure of 800-900 MPa and cured afterwards for 2 hours at 180 oC. The influence of dopes' materials kind on magnetic and mechanical composites were unilaterally and uniaxially pressed at room temperature under properties of composite materials was estimated. Metallographic examination of the composite materials' structure and XRD analysis has been made. Investigations of magnetic properties of composite materials show the influence of the addition material. It was estimated that dopes of soft magnetic material decrease coercive force HcB and slightly reduce remanence Br of composite. The addition of non-magnetic material decreases coercive force HcB and reduces remanence Br. Metallographic examination of the structure shows uniform distribution of Nd-Fe-B powder in the polymer matrix, grains are irregular elongated in the direction. Dopes distribution in a polymer matrix is irregular, agglomerations of powders of aluminium, iron and copper casting alloy with tin have noticed. Ultimate compressive strength of composite materials is improved for all the addition material, except powder of aluminium oxide. XRD analysis has identified the hard magnetic phase Nd2Fe14B. (author)

  19. Glass formation in a mixture of hard disks and hard ellipses.

    Science.gov (United States)

    Xu, Wen-Sheng; Duan, Xiaozheng; Sun, Zhao-Yan; An, Li-Jia

    2015-06-14

    We present an event-driven molecular dynamics study of glass formation in two-dimensional binary mixtures composed of hard disks and hard ellipses, where both types of particles have the same area. We demonstrate that characteristic glass-formation behavior appears upon compression under appropriate conditions in such systems. In particular, while a rotational glass transition occurs only for the ellipses, both types of particles undergo a kinetic arrest in the translational degrees of freedom at a single density. The translational dynamics for the ellipses is found to be faster than that for the disks within the same system, indicating that shape anisotropy promotes the translational motion of particles. We further examine the influence of mixture's composition and aspect ratio on the glass formation. For the mixtures with an ellipse aspect ratio of k = 2, both translational and rotational glass transition densities decrease with increasing the disk concentration at a similar rate, and hence, the two glass transitions remain close to each other at all concentrations investigated. By elevating k, however, the rotational glass transition density diminishes at a faster rate than the translational one, leading to the formation of an orientational glass for the ellipses between the two transitions. Our simulations imply that mixtures of particles with different shapes emerge as a promising model for probing the role of particle shape in determining the properties of glass-forming liquids. Furthermore, our work illustrates the potential of using knowledge concerning the dependence of glass-formation properties on mixture's composition and particle shape to assist in the rational design of amorphous materials. PMID:26071719

  20. Orthogonal versus covariant Lyapunov vectors for rough hard disk systems

    OpenAIRE

    Bosetti, Hadrien; Posch, Harald A.

    2011-01-01

    The Oseledec splitting of the tangent space into covariant subspaces for a hyperbolic dynamical system is numerically accessible by computing the full set of covariant Lyapunov vectors. In this paper, the covariant Lyapunov vectors, the orthogonal Gram-Schmidt vectors, and the corresponding local (time-dependent) Lyapunov exponents, are analyzed for a planar system of rough hard disks (RHDS). These results are compared to respective results for a smooth-hard-disk system (SHDS). We find that t...

  1. Local energy: a basis for local electronegativity and local hardness

    OpenAIRE

    Gal, Tamas

    2011-01-01

    The traditional approach to establishing a local measure of chemical hardness, by defining a local hardness concept through the derivative of the chemical potential with respect to the electron density, has been found to have limited chemical applicability, and has proved to be an unfeasible approach in principle. Here, we propose a new approach via a unique local energy concept. This local energy is shown to emerge from the Hamilton-Jacobi kind of construction of Schrodinger's quantum mechan...

  2. Hardness and elasticity of abrasive particles measured by instrumented indentation

    OpenAIRE

    Hvizdoš, P.

    2015-01-01

    Basic mechanical properties of seven types (from seven different sites) of abrasive garnet particles used for water jet cutting were measured using the technique of instrumented indentation (also called depth sensing indentation or nanoindentation). Hardness and modulus of elasticity were evaluated and compared. All the abrasives had similar measured mechanical properties (hardness 20 – 24.16 GPa), the highest values were found for the Czech garnet.

  3. Hard exclusive reactions and generalized parton distributions at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Dueren, M. [II. Phys. Inst., Univ. Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

    2009-06-15

    The concept of generalized parton distributions is discussed and applied to hard exclusive reactions at the HERMES experiment at DESY. Recent results on hard exclusive meson production and in particular on deeply virtual Compton scattering are presented. For the first time, information about the orbital angular momentum of quarks in the nucleon can be extracted from experiment. Using a new detector for recoil particles, HERMES will be able to give even more complete results in future.

  4. Marine plastic litter as an artificial hard bottom fouling ground

    Science.gov (United States)

    Harms, J.

    1990-09-01

    20 fouling organisms were observed on plastic litter dredged from the Elbe estuary during July 1990; 60% of the species were typical sessile hard bottom organisms. Most individuals found on this artificial hard bottom were barnacles ( Balanus crenatus, Elminius modestus), the mussel Mytilus edulis and the polychaete Lanice conchilega. All individuals were juveniles which had settled only recently on the plastics. The earliest settlers were not much older than 4 8 weeks.

  5. Removal of mineral oil and wastewater pollutants using hard coal

    OpenAIRE

    BRANISLAV R. SIMONOVIĆ; DRAGANA ARANĐELOVIĆ; MIĆA JOVANOVIĆ; BRANIMIR KOVAČEVIĆ; LATO PEZO; ACA JOVANOVIĆ

    2009-01-01

    This study investigates the use of hard coal as an adsorbent for removal of mineral oil from wastewater. In order to determine the efficiency of hard coal as an adsorbent of mineral oil, process parameters such as sorption capacity (in static and dynamic conditions), temperature, pH, contact time, flow rate, and chemical pretreatment were evaluated in a series of batch and continuous flow experiments. There were significant differences in the mineral oil removal for various pH values examined...

  6. Decrease and conquer: Phacoemulsification technique for hard nucleus cataracts.

    Science.gov (United States)

    Kim, Hong Kyun

    2009-10-01

    I describe a technique to improve the control and safety of phacoemulsification during hard nucleus cataract surgery. Whereas the goal of the conventional nucleofractis technique is complete fragmentation of the lens, the technique aims to separate the endonuclear core from the epinucleus. This is done in 3 steps: circumferential disassembly, decreasing the central nucleus volume, and conquering the remnant. The technique offers safer and more effective phacoemulsification in patients with hard nucleus cataracts. PMID:19781457

  7. The Role Played by Computation in Understanding Hard Materials

    OpenAIRE

    John Edward Lowther

    2011-01-01

    In the last decade, computation has played a valuable role in the understanding of materials. Hard materials, in particular, are only part of the application. Although materials involving B, C, N or O remain the most valued atomic component of hard materials, with diamond retaining its distinct superiority as the hardest, other materials involving a wide variety of metals are proving important. In the present work the importance of both ab-initio approaches and molecular dynamics aspects will...

  8. Hard exclusive reactions and generalized parton distributions at HERMES

    International Nuclear Information System (INIS)

    The concept of generalized parton distributions is discussed and applied to hard exclusive reactions at the HERMES experiment at DESY. Recent results on hard exclusive meson production and in particular on deeply virtual Compton scattering are presented. For the first time, information about the orbital angular momentum of quarks in the nucleon can be extracted from experiment. Using a new detector for recoil particles, HERMES will be able to give even more complete results in future.

  9. Hard exclusive reactions and generalized parton distributions at HERMES

    Science.gov (United States)

    Düren, M.; Hermes Collaboration

    2009-06-01

    The concept of generalized parton distributions is discussed and applied to hard exclusive reactions at the HERMES experiment at DESY. Recent results on hard exclusive meson production and in particular on deeply virtual Compton scattering are presented. For the first time, information about the orbital angular momentum of quarks in the nucleon can be extracted from experiment. Using a new detector for recoil particles, HERMES will be able to give even more complete results in future.

  10. Subgroup report on hard x-ray microprobes

    International Nuclear Information System (INIS)

    The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E≥5 keV) microprobes. New x-ray optics have been demonstrated which show promise for achieving intense submicron hard x-ray probes. These probes will be used for extraordinary elemental detection by x-ray fluorescence/absorption and for microdiffraction to identify phase and strain. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature makes the development of an advanced hard x-ray microprobe an important national goal. In this workshop state-of-the-art hard x-ray microprobe optics were described and future directions were discussed. Gene Ice, Oak Ridge National Laboratory (ORNL), presented an overview of the current status of hard x-ray microprobe optics and described the use of crystal spectrometers to improve minimum detectable limits in fluorescent microprobe experiments. Al Thompson, Lawrence Berkeley Laboratory (LBL), described work at the Center for X-ray Optics to develop a hard x-ray microprobe based on Kirkpatrick-Baez (KB) optics. Al Thompson also showed the results of some experimental measurements with their KB optics. Malcolm Howells presented a method for bending elliptical mirrors and Troy Barbee commented on the use of graded d spacings to achieve highest efficiency in KB multilayer microfocusing. Richard Bionta, Lawrence Livermore National Laboratory (LLNL), described the development of the first hard x-ray zone plates and future promise of so called open-quotes jelly rollclose quotes or sputter slice zone plates. Wenbing Yun, Argonne National Laboratory (ANL), described characterization of jelly roll and lithographically produced zone plates and described the application of zone plates to focus extremely narrow bandwidths by nuclear resonance. This report summarizes the presentations of the workshop subgroup on hard x-ray microprobes

  11. Universal Voting Protocol Tweaks to Make Manipulation Hard

    OpenAIRE

    Conitzer, Vincent; Sandholm, Tuomas

    2003-01-01

    Voting is a general method for preference aggregation in multiagent settings, but seminal results have shown that all (nondictatorial) voting protocols are manipulable. One could try to avoid manipulation by using voting protocols where determining a beneficial manipulation is hard computationally. A number of recent papers study the complexity of manipulating existing protocols. This paper is the first work to take the next step of designing new protocols that are especially hard to manipula...

  12. Semi empirical hardness predictive model for AZ91 nanocomposite

    Science.gov (United States)

    Zaidi, N. H. A.; Jamaludin, S. B.; Zaidi, A. M. A.; Ahmad, K. R.

    2016-07-01

    AZ91 nanocomposite was exposed to several heat treatment processes and the effect of precipitation hardening on hardness was studied as a function of time and temperature. The investigation shows the significant of time and temperature are the main role in the precipitation hardening process of the nanocomposite. Kinetics study show a deceptive activation energy of 21 kJ/mol of the AZ91 nanocomposite. A relationship was derived to predict the maximum hardness at given time and temperature.

  13. Progress in the theory of hard exclusive processes

    International Nuclear Information System (INIS)

    Recent progresses in the theory of hard exclusive processes are reviewed. The hard scattering mechanism and the factorization of perturbative QCD amplitudes from wave-function-like quantities is now well understood. The effects of soft gluon radiation are controlled through Sudakov form factors which protect observables from dangerous end-point contributions. The phenomenology of this mature framework is eagerly waiting for precise experimental data in a domain where transfers are O(10 GeV2). (author). 11 refs., 2 figs

  14. Research on polyamide matrix composites filled with hard coal

    OpenAIRE

    M. Rojek; J. Stabik; M. Szymiczek; Ł. Suchoń; K. Mrowiec

    2012-01-01

    Purpose: The aim of this paper is to present the summary results of studies on polyamide composites filled with hard coal. Research on the use of coal as a filler of polymers are conducted for many years in Division of Metallic and Polymeric Materials Processing, Silesian University of Technology. This paper summarizes results obtained in different research programmes preformed in recent years. Described materials are polyamide 6 composites filled with modified and unmodified hard coal powde...

  15. Hard coal modified with silanes as polyamide filler

    OpenAIRE

    M. Rojek; J. Stabik; Ł. Suchoń

    2010-01-01

    Purpose: This paper shows the influence of coupling agents, especially silanes, on mechanical properties of polyamide 6 filled with hard coal dust.Design/methodology/approach: Before preparing compositions, pulverised filler surface was modified with coupling agents. Then, it was compounded using a twin-screw extruder composite consisting of modified hard coal and polyamide 6. A blend was granulated later and test samples were subjected to injection moulding. Afterwards, mechanical properties...

  16. Investigation of processing properties of polyamide filled with hard coal

    OpenAIRE

    J. Stabik; Ł. Suchoń; M. Rojek; M. Szczepanik

    2009-01-01

    Purpose: The aim of this article is to present the influence of contents and kind of hard coal used as powder filler on rheological properties (viscosity) of polyamide 6.Design/methodology/approach: Preparation of composite of polyamide 6 with hard coal was carried out on laboratory twin screw extruder. Extruded composite was granulated and in this form was used for MFR analysis. Taking into account MFR results viscosity was calculated. The influence of filler content on viscosity was next se...

  17. Statistical theory of correlations in random packings of hard particles

    OpenAIRE

    Jin, Yuliang; Puckett, James G.; Makse, Hernan A.

    2014-01-01

    A random packing of hard particles represents a fundamental model for granular matter. Despite its importance, analytical modeling of random packings remains difficult due to the existence of strong correlations which preclude the development of a simple theory. Here, we take inspiration from liquid theories for the $n$-particle angular correlation function to develop a formalism of random packings of hard particles from the bottom-up. A progressive expansion into a shell of particles converg...

  18. Hard Sphere Dynamics for Normal and Granular Fluids

    OpenAIRE

    Dufty, James W.; Baskaran, Aparna

    2005-01-01

    A fluid of N smooth, hard spheres is considered as a model for normal (elastic collisions) and granular (inelastic collisions) fluids. The potential energy is discontinuous for hard spheres so the pairwise forces are singular and the usual forms of Newtonian and Hamiltonian mechanics do not apply. Nevertheless, particle trajectories in the N particle phase space are well defined and the generators for these trajectories can be identified. The first part of this presentation is a review of the...

  19. Improvement in hardness of soda-lime-silica glass

    International Nuclear Information System (INIS)

    Hardness is a key design parameter for structural application of brittle solids like glass. Here we report for the first time the significant improvement of about 10% in Vicker's hardness of a soda-lime-silica glass with loading rate in the range of 0.1-10 N.s-1. Corroborative dark field optical and scanning electron microscopy provided clue to this improvement through evidence of variations in spatial density of shear deformation band formation as a function of loading rate.

  20. The Hardness and Strength Properties of WC-Co Composites

    OpenAIRE

    Ronald W. Armstrong

    2011-01-01

    The industrially-important WC-Co composite materials provide a useful, albeit complicated materials system for understanding the combined influences on hardness and strength properties of the constituent WC particle strengths, the particle sizes, their contiguities, and of Co binder hardness and mean free paths, and in total, the volume fraction of constituents. A connection is made here between the composite material properties, especially including the material fracture toughness, and the s...

  1. Investigation of processing properties of polyamide filled with hard coal

    Directory of Open Access Journals (Sweden)

    J. Stabik

    2009-04-01

    Full Text Available Purpose: The aim of this article is to present the influence of contents and kind of hard coal used as powder filler on rheological properties (viscosity of polyamide 6.Design/methodology/approach: Preparation of composite of polyamide 6 with hard coal was carried out on laboratory twin screw extruder. Extruded composite was granulated and in this form was used for MFR analysis. Taking into account MFR results viscosity was calculated. The influence of filler content on viscosity was next searched.Findings: Results of research showed that addition of powdered hard coal to polyamide 6 matrix cause pronounced decrease of MFR index. In this way significant increase of viscous flow was observed. It is often observed phenomenon for polymer composite filled with powder materials.Research limitations/implications: It is necessary to carry out the research with surface modified hard coal with coupling agents which provide better adhesion of polymer matrix to filler.Practical implications: Hard coal used as a filler in composites makes it possible to gain new and cheaper polymeric materials with many possible applications.Originality/value: Investigation described in article shows possibility of hard coal application as innovatory filler of polymers. The influence of this filler on rheological properties indicate that processing of these new materials may be accompanied with some problems.

  2. Hardness profile measurements in functionally graded WC-Co composites

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, C.; Oden, M

    2004-09-25

    Micro- and nanoindentation were used to determine hardness as a function of depth in two functionally graded WC-Co composites. The gradients were continuous (extended over {approx}70 and {approx}40 {mu}m, respectively) and consisted of varying WC and Co phase volume fractions. Five comparable homogeneous samples with different Co contents and different average WC grain sizes were also used for direct comparison. A relationship between hardness and Co content was established for both the graded and the homogeneous samples wherein the hardness decreased with increasing Co content. The magnitude of the hardness was the same (for a given Co content) for the functionally graded and the homogeneous materials. The hardness measurements were also correlated with X-ray diffraction studies of thermal residual stresses and the absence of any major influence explained. It is generally concluded that the hardness values are dominated by the local Co content. Additionally, the examination of surface cracks around indents suggests that compositional gradients in WC-Co composites offer increased toughness.

  3. Hardness profile measurements in functionally graded WC-Co composites

    International Nuclear Information System (INIS)

    Micro- and nanoindentation were used to determine hardness as a function of depth in two functionally graded WC-Co composites. The gradients were continuous (extended over ∼70 and ∼40 μm, respectively) and consisted of varying WC and Co phase volume fractions. Five comparable homogeneous samples with different Co contents and different average WC grain sizes were also used for direct comparison. A relationship between hardness and Co content was established for both the graded and the homogeneous samples wherein the hardness decreased with increasing Co content. The magnitude of the hardness was the same (for a given Co content) for the functionally graded and the homogeneous materials. The hardness measurements were also correlated with X-ray diffraction studies of thermal residual stresses and the absence of any major influence explained. It is generally concluded that the hardness values are dominated by the local Co content. Additionally, the examination of surface cracks around indents suggests that compositional gradients in WC-Co composites offer increased toughness

  4. Aespoe Hard Rock Laboratory. Annual Report 2001

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The bedrock with available fractures and fracture zones, its properties and on-going physical, chemical and biological processes which affect the integrity of the engineered barriers and the transport of radionuclides are denoted the natural barriers of a deep repository. Experiments are performed at Aespoe HRL at conditions that are expected to prevail at repository depth, with the aim to increase the knowledge of the long term function of the repository barriers. Another aim with the Aespoe HRL is testing of models for groundwater flow, radionuclide migration, chemical and biological processes. The programme for the testing of models includes evaluation of the usefulness and reliability of different models and the development and testing of methods for determination of parameters required as input to conceptual and numerical models. Ongoing projects are Tracer Retention Understanding Experiments, Long Term Diffusion Experiment, Radionuclide Retention Experiment, Microbial Project, Colloid Project, and Matrix Water Chemistry Experiments. The activities at Aespoe HRL include the evaluation of the usefulness and reliability of different calculation models and the development and testing of methods for determination of parameters required as input to the models. An important part of this work is performed in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, an international co-operation project. The work within the Tasks 4 and 5 were reported during 2001

  5. Aespoe Hard Rock Laboratory. Annual Report 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The bedrock with available fractures and fracture zones, its properties and on-going physical, chemical and biological processes which affect the integrity of the engineered barriers and the transport of radionuclides are denoted the natural barriers of a deep repository. Experiments are performed at Aespoe HRL at conditions that are expected to prevail at repository depth, with the aim to increase the knowledge of the long term function of the repository barriers. Another aim with the Aespoe HRL is testing of models for groundwater flow, radionuclide migration, chemical and biological processes. The programme for the testing of models includes evaluation of the usefulness and reliability of different models and the development and testing of methods for determination of parameters required as input to conceptual and numerical models. Ongoing projects are Tracer Retention Understanding Experiments, Long Term Diffusion Experiment, Radionuclide Retention Experiment, Microbial Project, Colloid Project, and Matrix Water Chemistry Experiments. The activities at Aespoe HRL include the evaluation of the usefulness and reliability of different calculation models and the development and testing of methods for determination of parameters required as input to the models. An important part of this work is performed in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, an international co-operation project. The work within the Tasks 4 and 5 were reported

  6. Aespoe hard rock laboratory. Annual report 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of

  7. Aespoe Hard Rock Laboratory. Annual Report 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2009 is given below. Geoscience Geoscientific research is a basic activity at Aespoe HRL. The aim of the current studies is to develop geoscientific models of the Aespoe HRL and increase the understanding of the rock mass properties as well as knowledge of applicable methods of measurement. A main task within the geoscientific field is the development of the Aespoe Site Descriptive Model (SDM) integrating information from the different fields. The main activities in the geoscientific fields have been: (1) Geology evaluation of geological mapping techniques leading to the decision to develop a SKB mapping system and finalization of the mapping of rock surfaces in the new tunnel, (2) Hydrogeology monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics finalised the field tests on thermally-induced spalling in deposition holes and evaluated the effect of counterforce in the deposition holes. Natural barriers At Aespoe HRL

  8. Aespoe Hard Rock Laboratory. Annual Report 2008

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. The main activities in the geoscientific fields have been: (1) Geology - completion of the feasibility study concerning geological mapping techniques and mapping of rock surfaces in the new tunnel, (2) Hydrogeology - monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field tests to evaluate the counterforce needed to prevent thermally-induced spalling in deposition holes. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. A number of large-scale field experiments and supporting activities concerning Engineered barriers are carried out at Aespoe HRL. The experiments focus on different aspects of engineering technology and performance testing: The Prototype Repository is a demonstration of the integrated function of the repository and provides a full-scale reference for tests of predictive models concerning individual components as well as the complete repository system; The Long Term Test of Buffer Material (Lot-experiment) aims at validating models and hypotheses concerning physical properties in a bentonite buffer material and of related processes regarding microbiology, radionuclide transport, copper corrosion and gas transport; The objective of the project Alternative

  9. Anisotropic diffusion of concentrated hard-sphere colloids near a hard wall studied by evanescent wave dynamic light scattering

    OpenAIRE

    Michailidou, V. N.; Swan, J. W.; Brady, J. F.; Petekidis, G.

    2013-01-01

    Evanescent wave dynamic light scattering and Stokesian dynamics simulations were employed to study the dynamics of hard-sphere colloidal particles near a hard wall in concentrated suspensions. The evanescent wave averaged short-time diffusion coefficients were determined from experimental correlation functions over a range of scattering wave vectors and penetration depths. Stokesian dynamics simulations performed for similar conditions allow a direct comparison of both the short-time self- an...

  10. HARD X-RAY AND MICROWAVE EMISSIONS FROM SOLAR FLARES WITH HARD SPECTRAL INDICES

    International Nuclear Information System (INIS)

    We analyze 10 flare events that radiate intense hard X-ray (HXR) emission with significant photons over 300 keV to verify that the electrons that have a common origin of acceleration mechanism and energy power-law distribution with solar flares emit HXRs and microwaves. Most of these events have the following characteristics. HXRs emanate from the footpoints of flare loops, while microwaves emanate from the tops of flare loops. The time profiles of the microwave emission show delays of peak with respect to those of the corresponding HXR emission. The spectral indices of microwave emissions show gradual hardening in all events, while the spectral indices of the corresponding HXR emissions are roughly constant in most of the events, though rather rapid hardening is simultaneously observed in some for both indices during the onset time and the peak time. These characteristics suggest that the microwave emission emanates from the trapped electrons. Then, taking into account the role of the trapping of electrons for the microwave emission, we compare the observed microwave spectra with the model spectra calculated by a gyrosynchrotron code. As a result, we successfully reproduce the eight microwave spectra. From this result, we conclude that the electrons that have a common acceleration and a common energy distribution with solar flares emit both HXR and microwave emissions in the eight events, though microwave emission is contributed to by electrons with much higher energy than HXR emission.

  11. Polarization observables in hard rescattering mechanism of deuteron photodisintegration

    International Nuclear Information System (INIS)

    Polarization properties of high energy photodisintegration of the deuteron are studied within the framework of the hard rescattering mechanism (HRM). In HRM, a quark of one nucleon knocked-out by the incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with high relative momentum. Summation of all relevant quark rescattering amplitudes allows us to express the scattering amplitude of the reaction through the convolution of a hard photon-quark interaction vertex, the large angle p-n scattering amplitude and the low momentum deuteron wave function. Within HRM, it is demonstrated that the polarization observables in hard photodisintegration of the deuteron can be expressed through the five helicity amplitudes of NN scattering at high momentum transfer. At 90 deg. CM scattering HRM predicts the dominance of the isovector channel of hard pn rescattering, and it explains the observed smallness of induced, Py and transfered, Cx polarizations without invoking the argument of helicity conservation. Namely, HRM predicts that Py and Cx are proportional to the phi5 helicity amplitude which vanishes at θcm=90 deg. due to symmetry reasons. HRM predicts also a nonzero value for Cz in the helicity-conserving regime and a positive Σ asymmetry which is related to the dominance of the isovector channel in the hard reinteraction. We extend our calculations to the region where large polarization effects are observed in pp scattering as well as give predictions for angular dependences

  12. Hard photodisintegration of a proton pair in {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Stanley Brodsky; Leonid Frankfurt; Ronald Gilman; J. R. Hiller; G. A. Miller; Eliezer Piasetzky; Misak Sargsian; Mark Strikman

    2003-05-01

    Hard photodisintegration of the deuteron has been extensively studied in order to understand the dynamics of the transition from hadronic to quark-gluon descriptions of the strong interaction. In this work, we discuss the extension of this program to hard photodisintegration of a pp pair in the {sup 3}He nucleus. Experimental confirmation of new features predicted here for the suggested reaction would advance our understanding of hard nuclear reactions. A main prediction, in contrast with low-energy observations, is that the pp breakup cross section is not much smaller than the one for pn break up. In some models, the energy-dependent oscillations observed for pp scattering are predicted to appear in the {gamma} {sup 3}He {yields} pp + n reaction. Such an observation would open up a completely new field in studies of color coherence phenomena in hard nuclear reactions. We also demonstrate that, in addition to the energy dependence, the measurement of the light-cone momentum distribution of the recoil neutron provides an independent test of the underlying dynamics of hard disintegration.

  13. A standard procedure for measuring pellet hardness of rodent diets.

    Science.gov (United States)

    Thigpen, J E; Locklear, J; Romines, C; Taylor, K A; Yearby, W; Stokes, W S

    1993-10-01

    A Chatillon Model TCM-200 test stand with exchangeable flat horizontal or concave receptacle bases and a DFI-200 gauge load cell with multiple types of upper exchangeable test jaws (large round-flat, medium round-flat, chisel, bullet, and cone-shaped) were compared by using preautoclaved and autoclaved NIH-31 rodent diet pellets to determine which type of hardness testing system would give the most accurate and reproducible results for measuring pellet hardness. The type and size of the contact area of the upper jaws significantly affected the force required to break the pellets. Significant differences were observed between the flat-horizontal and concave receptacle bases in the force required to break the pellets when using the two round-flat upper jaws. In contrast, similar results were obtained with both bases when the bullet, chisel, or cone-shaped upper jaws were used. Autoclaved pellets were 69.4% (range, 49 to 94%) harder than preautoclaved pellets. These results suggest that different testing systems can be used for measuring pellet hardness and that a standard procedure must be used in order to compare pellet hardness results between different testing laboratories. It was concluded that the flat-horizontal base and the larger round-flat end upper jaw gave the most reproducible results for measuring pellet hardness. PMID:8277732

  14. Study on indium leaching from mechanically activated hard zinc residue

    Directory of Open Access Journals (Sweden)

    Yao J.H.

    2011-01-01

    Full Text Available In this study, changes in physicochemical properties and leachability of indium from mechanically activated hard zinc residue by planetary mill were investigated. The results showed that mechanical activation increased specific surface area, reaction activity of hard zinc residue, and decreased its particle size, which had a positive effect on indium extraction from hard zinc residue in hydrochloric acid solution. Kinetics of indium leaching from unmilled and activated hard zinc residue were also investigated, respectively. It was found that temperature had an obvious effect on indium leaching rate. Two different kinetic models corresponding to reactions which are diffusion controlled, [1-(1- x1/3]2=kt and (1-2x/3-(1-x2/3=kt were used to describe the kinetics of indium leaching from unmilled sample and activated sample, respectively. Their activation energies were determined to be 17.89 kJ/mol (umilled and 11.65 kJ/mol (activated within the temperature range of 30°C to 90°C, which is characteristic for a diffusion controlled process. The values of activation energy demonstrated that the leaching reaction of indium became less sensitive to temperature after hard zinc residue mechanically activated by planetary mill.

  15. Hard error generation by neutron-induced fission fragments

    International Nuclear Information System (INIS)

    The authors observed that neutron-induced fission of uranium contaminants present in alumina ceramic package lids results in the release of fission fragments that can cause hard errors in metal-nitride-oxide nonvolatile RAMs (MNOS NVRAMs). Hard error generation requires the simultaneous presence of (1) a fission fragment with a linear energy transfer (LET) greater than 20 MeV/mg/cm/sup **2/ moving at an angle of 30 degrees or less from the electric field in the high-field, gate region of the memory transistor, and (2) a WRITE or ERASE voltage on the oxide-nitride transistor gate. In reactor experiments, they observe these hard errors when a ceramic lid is used on both MNOS NVRAMs and polysilicon-nitride-oxide (SNOS) capacitors, but hard errors are not observed when a gold-plated kovar lid is used on the package containing these die. They mapped the tracks of the fission fragments released from the ceramic lids with a mica track detector and used a Monte Carlo model of fission fragment transport through the ceramic lid to measure the concentration of uranium present in the lids. The authors' concentration measurements are in excellent agreement with other's measurement of uranium concentration in ceramic lids. The authors' Monte Carlo analyses also agree closely with their measurements of hard error probability in MNOS NVRAMs

  16. An overview on polynomial approximation of NP-hard problems

    Directory of Open Access Journals (Sweden)

    Paschos Vangelis Th.

    2009-01-01

    Full Text Available The fact that polynomial time algorithm is very unlikely to be devised for an optimal solving of the NP-hard problems strongly motivates both the researchers and the practitioners to try to solve such problems heuristically, by making a trade-off between computational time and solution's quality. In other words, heuristic computation consists of trying to find not the best solution but one solution which is 'close to' the optimal one in reasonable time. Among the classes of heuristic methods for NP-hard problems, the polynomial approximation algorithms aim at solving a given NP-hard problem in poly-nomial time by computing feasible solutions that are, under some predefined criterion, as near to the optimal ones as possible. The polynomial approximation theory deals with the study of such algorithms. This survey first presents and analyzes time approximation algorithms for some classical examples of NP-hard problems. Secondly, it shows how classical notions and tools of complexity theory, such as polynomial reductions, can be matched with polynomial approximation in order to devise structural results for NP-hard optimization problems. Finally, it presents a quick description of what is commonly called inapproximability results. Such results provide limits on the approximability of the problems tackled.

  17. Hard X-ray properties of magnetic cataclysmic variables

    CERN Document Server

    Scaringi, S; Norton, A J; Knigge, C; Hill, A B; Clark, D J; Dean, A J; McBride, V A; Barlow, E J; Bassani, L; Bazzano, A; Fiocchi, M; Landi, R

    2009-01-01

    Hard X-ray surveys have proven remarkably efficient in detecting intermediate polars and asynchronous polars, two of the rarest type of cataclysmic variable (CV). Here we present a global study of hard X-ray selected intermediate polars and asynchronous polars, focusing particularly on the link between hard X-ray properties and spin/orbital periods. To this end, we first construct a new sample of these objects by cross-correlating candidate sources detected in INTEGRAL/IBIS observations against catalogues of known CVs. We find 23 cataclysmic variable matches, and also present an additional 9 (of which 3 are definite) likely magnetic cataclysmic variables (mCVs) identified by others through optical follow-ups of IBIS detections. We also include in our analysis hard X-ray observations from Swift/BAT and SUZAKU/HXD in order to make our study more complete. We find that most hard X-ray detected mCVs have P_{spin}/P_{orb}<0.1 above the period gap. In this respect we also point out the very low number of detecte...

  18. Hard Photodisintegration of 3He into pd pair

    CERN Document Server

    Maheswari, Dhiraj

    2016-01-01

    The recent measurements of high energy photodisintegration of the $^3He$ nucleus to the $pd$ pair at $90^0$ center of mass demonstrated an energy scaling consistent with the quark counting rule with unprecedentedly large exponent of $s^{-17}$. To understand the underlying mechanism of this process we extended the theoretical formalism of hard rescattering mechanism to calculate the $\\gamma ^3He\\rightarrow pd$ reaction. In HRM the incoming high energy photon strikes a quark from one of the nucleons in the target which subsequently undergoes hard rescattering with the quarks from the other nucleons generating hard two-body system in the final state of the reaction. Within the HRM we derived the parameter free expression for the differential cross section of the reaction, which is expressed through the $^3He\\rightarrow pd$ transition spectral function, cross section of hard $pd\\rightarrow pd$ scattering and the effective charge of the quarks being interchanged during the hard rescattering process. The numerical ...

  19. Tribology; Cold rolling mill roll; Hard chrome; Surface texturing.

    Directory of Open Access Journals (Sweden)

    José Lucio Gonçalves Junior

    2012-12-01

    Full Text Available The present work analyzes the tribological behavior of surface modifications often used in cold rolling mill rolls. Different surface modifications were carried out on samples produced from a fragment of the rolling mill roll: i texturing; ii chromium plating; iii texturing with subsequent hard chrome plating; iv and hard chrome plating with subsequent texturing. Before the surface modifications the samples were heat treated and ground on both faces. Wear tests were performed using a reciprocating movement of a ball over flat configuration under a load of 9.8 N. It is observed that there is no significant change in the coefficient of friction as a function of surface modification. Surface texturing increases the wear of the counter body, while the hard chromium coating reduces it. The addition of hard chromium coating promotes the formation of a tribolayer on the counter body consisting of chromium and oxygen. On the other hand, for the samples without hard chrome coating, the tribolayer consists of iron and oxygen

  20. Hard coal modified with silanes as polyamide filler

    Directory of Open Access Journals (Sweden)

    M. Rojek

    2010-03-01

    Full Text Available Purpose: This paper shows the influence of coupling agents, especially silanes, on mechanical properties of polyamide 6 filled with hard coal dust.Design/methodology/approach: Before preparing compositions, pulverised filler surface was modified with coupling agents. Then, it was compounded using a twin-screw extruder composite consisting of modified hard coal and polyamide 6. A blend was granulated later and test samples were subjected to injection moulding. Afterwards, mechanical properties were evaluated. These properties have essential meaning for applications of new composites as structural materials.Findings: Tests demonstrated that modification of powdered hard coal surface with coupling agents had not significant effect on mechanical properties of polyamide/hard coal composites.Research limitations/implications: Applied compounding procedure did not allow to achieve good compositions homogenisation. A new method to be applied is planned in future research. Simultaneously, it is necessary to investigate composites with other coupling agents which will improve filler’s adhesion to a polymer. Long-term test are also planned.Practical implications: Hard coal, cheap and widely available filler, used to modify thermoplastic polymers, enable to obtain new materials with attractive properties and many applications.Originality/value: Paper represents innovative polymer filler and methods to modify it.

  1. Tuning hardness in calcite by incorporation of amino acids

    Science.gov (United States)

    Kim, Yi-Yeoun; Carloni, Joseph D.; Demarchi, Beatrice; Sparks, David; Reid, David G.; Kunitake, Miki E.; Tang, Chiu C.; Duer, Melinda J.; Freeman, Colin L.; Pokroy, Boaz; Penkman, Kirsty; Harding, John H.; Estroff, Lara A.; Baker, Shefford P.; Meldrum, Fiona C.

    2016-08-01

    Structural biominerals are inorganic/organic composites that exhibit remarkable mechanical properties. However, the structure-property relationships of even the simplest building unit--mineral single crystals containing embedded macromolecules--remain poorly understood. Here, by means of a model biomineral made from calcite single crystals containing glycine (0-7 mol%) or aspartic acid (0-4 mol%), we elucidate the origin of the superior hardness of biogenic calcite. We analysed lattice distortions in these model crystals by using X-ray diffraction and molecular dynamics simulations, and by means of solid-state nuclear magnetic resonance show that the amino acids are incorporated as individual molecules. We also demonstrate that nanoindentation hardness increased with amino acid content, reaching values equivalent to their biogenic counterparts. A dislocation pinning model reveals that the enhanced hardness is determined by the force required to cut covalent bonds in the molecules.

  2. White Layer of Hard Turned Surface by Sharp CBN Tool

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-ping; SONG He-chuan; C.Richard Liu

    2005-01-01

    White layers in hard turned surfaces were identified and measured as a function of turning parameters based on the Taguchi method. It reveals that white layers generate on the machine surface in the absence of tool flank wear, and white layer depth varies with the different combinations of hard turning parameters. Turning speed has the most important impact on white layer depth, feed rate follows, and cutting depth at last. The white layer generation consequently suggests a strong couple relation to the heat generation and thermal process of hard turning operation. White layer disappears under an optimal combination of turning parameters by Taguchi method. It suggests that a superior surface integrity without white layer is feasible under some selected combinations of turning parameters by a sharp CBN cutting tool.

  3. Scheduling Algorithms Based on Weakly Hard Real-Time Constraints

    Institute of Scientific and Technical Information of China (English)

    TU Gang (涂刚); YANG FuMin (阳富民); LU YanSheng (卢炎生)

    2003-01-01

    The problem of scheduling weakly hard real-time tasks is addressed in this paper.The paper first analyzes the characters ofμ-pattern and weakly hard real-time constraints, then,presents two scheduling algorithms, Meet Any Algorithm and Meet Row Algorithm, for weakly hard real-time systems. Different from traditional algorithms used to guarantee deadlines, Meet Any Algorithm and Meet Row Algorithm can guarantee both deadlines and constraints. Meet Any Algorithm and Meet Row Algorithm try to find out the probabilities of tasks breaking constraints and increase task's priority in advance, but not till the last moment. Simulation results show that these two algorithms are better than other scheduling algorithms dealing with constraints and can largely decrease worst-case computation time of real-time tasks.

  4. Implications of confining force field structures in hard hadronic processes

    International Nuclear Information System (INIS)

    This thesis is centered on the study of confining force field structures in hard scattering processes. Perturbative QCD provides the means of calculating any process on the parton level, but to be able accurately to describe the actual outcome of an event, one still needs a phenomenological model for how quarks and gluons transform into observable hadrons. One such model is based on the assumption that the particles are produced by the confining fields stretched between the partons. The actual particle distributions will then depend on the topology of the confining fields. We have developed a Monte Carlo program to simulate complete events in hard scattering, and we use this to study the properties of the confining field in different trigger situations. We further look at the amount of hard processes that can be expected in experiments that trigger on transverse energy sum (calorimeter experiments). Finally, we investigate charm production within our model. (author)

  5. High flux lithium antineutrino source with variable hard spectrum

    CERN Document Server

    Lyashuk, V I

    2016-01-01

    The high flux antineutrino source with hard antineutrino spectrum based on neutron activation of 7Li and subsequent fast beta-decay (T 1/2 = 0.84 s) of the 8Li isotope with emission of antineutrino with energy up to 13 MeV - is discussed. Creation of the intensive isotope neutrino source of hard spectrum will allow to increase the detection statistics of neutrino interaction and it is especially urgent for oscillation experiments. The scheme of the proposed neutrino source is based on the continuous transport of the created 8Li to the neutrino detector, which moved away from the place of neutron activation. Analytical expressions for lithium antineutrino flux is obtained. The discussed source will ensure to increase the cross section for reactions with deuteron from several times to tens compare to the reactor antineutrino spectrum. An another unique feature of the installation is the possibility to vary smoothly the hardness of the antineutrino spectrum.

  6. Brownian dynamics simulations with hard-body interactions: Spherical particles

    CERN Document Server

    Behringer, Hans; 10.1063/1.4761827

    2012-01-01

    A novel approach to account for hard-body interactions in (overdamped) Brownian dynamics simulations is proposed for systems with non-vanishing force fields. The scheme exploits the analytically known transition probability for a Brownian particle on a one-dimensional half-line. The motion of a Brownian particle is decomposed into a component that is affected by hard-body interactions and into components that are unaffected. The hard-body interactions are incorporated by replacing the affected component of motion by the evolution on a half-line. It is discussed under which circumstances this approach is justified. In particular, the algorithm is developed and formulated for systems with space-fixed obstacles and for systems comprising spherical particles. The validity and justification of the algorithm is investigated numerically by looking at exemplary model systems of soft matter, namely at colloids in flow fields and at protein interactions. Furthermore, a thorough discussion of properties of other heurist...

  7. Statistical theory of correlations in random packings of hard particles.

    Science.gov (United States)

    Jin, Yuliang; Puckett, James G; Makse, Hernán A

    2014-05-01

    A random packing of hard particles represents a fundamental model for granular matter. Despite its importance, analytical modeling of random packings remains difficult due to the existence of strong correlations which preclude the development of a simple theory. Here, we take inspiration from liquid theories for the n-particle angular correlation function to develop a formalism of random packings of hard particles from the bottom up. A progressive expansion into a shell of particles converges in the large layer limit under a Kirkwood-like approximation of higher-order correlations. We apply the formalism to hard disks and predict the density of two-dimensional random close packing (RCP), ϕ(rcp) = 0.85 ± 0.01, and random loose packing (RLP), ϕ(rlp) = 0.67 ± 0.01. Our theory also predicts a phase diagram and angular correlation functions that are in good agreement with experimental and numerical data. PMID:25353787

  8. Hard chrome and molybdenum coatings produced by physical vapour deposition

    International Nuclear Information System (INIS)

    Coatings of solid solutions of carbon or nitrogen in chromium or molybdenum were prepared by cathodic magnetron sputtering. Carbon or nitrogen was introduced either through the gas phase by reactive sputtering or by direct sputtering of sintered composite targets. Chemical and structural analyses of films revealed the formation of supersaturated solid solutions for carbon or nitrogen concentrations of up to several weight per cent. The nitride and carbide phases predicted from the binary diagrams were not observed. The Cr-C and Mo-C coatings showed hardnesses of up to 2500 HV. The hardnesses of Mo-N and Cr-N reached 3000 HV. The wear and corrosion resistance of these coatings, which showed a dense structure, was superior to that of electrolytic hard chrome. (Auth.)

  9. Interactions of benzalkonium chloride with soft and hard contact lenses

    International Nuclear Information System (INIS)

    We measured the uptake and washout of benzalkonium chloride, using radioactive tracer, by representative hard and soft contact lenses. Uptake by soft contact lenses after 7 days of continuous exposure is high (30 to 56 micrograms/mg of lens weight), with a low percentage of washout in 24 hours (between 0.2% and 1.5% of total uptake). High-water content lenses absorb greater quantities of benzalkonium than do low-water content lenses. Hard lenses take up a much smaller quantity of benzalkonium but release between 30% and 60% of total uptake during washout for 24 hours. Fluorosilicone-acrylate polymer lenses adsorb and release the most preservative, while polymethylmethacrylate lenses (Paragon Optical Inc, Mesa, Ariz) adsorb and release the least. The released benzalkonium from either soft or hard lenses is of a sufficient concentration to be at or above the upper limits of safety

  10. Enhanced surface hardness by boron implantation in Nitinol alloy.

    Science.gov (United States)

    Lee, D H; Park, B; Saxena, A; Serene, T P

    1996-10-01

    Boron implantation into Nitinol alloy has a potential for developing improved Nitinol root canal instruments with excellent cutting properties, without affecting their superelastic bulk-mechanical properties. The surface hardness of nickel-titanium (NiTi) alloy, also known as "Nitinol" (50 atm% nickel+50 atm% titanium), has been improved by ion-beam surface modification. With an implantation dose of 4.8 x 10(17) boron/cm2, a high concentration of boron (30 atm%) is incorporated into NiTi alloy by 110 keV boron ions at room temperature (25 degrees C). Boron-implanted and unimplanted (pure) Nitinol alloys show surface hardness of 7.6 +/- 0.2 and 3.2 +/- 0.2 GPa, respectively, at the nanoindentation depth of 0.05 micron. The ion-beam-modified NiTi alloy exceeds the surface hardness of stainless steel. PMID:9198443

  11. Signature Schemes Secure against Hard-to-Invert Leakage

    DEFF Research Database (Denmark)

    Faust, Sebastian; Hazay, Carmit; Nielsen, Jesper Buus;

    2012-01-01

    -theoretically reveal the entire secret key. In this work, we propose the first constructions of digital signature schemes that are secure in the auxiliary input model. Our main contribution is a digital signature scheme that is secure against chosen message attacks when given an exponentially hard-to-invert function...... of the secret key. As a second contribution, we construct a signature scheme that achieves security for random messages assuming that the adversary is given a polynomial-time hard to invert function. Here, polynomial-hardness is required even when given the entire public-key – so called weak...... auxiliary input security. We show that such signature schemes readily give us auxiliary input secure identification schemes...

  12. The Hardness and Strength Properties of WC-Co Composites

    Directory of Open Access Journals (Sweden)

    Ronald W. Armstrong

    2011-07-01

    Full Text Available The industrially-important WC-Co composite materials provide a useful, albeit complicated materials system for understanding the combined influences on hardness and strength properties of the constituent WC particle strengths, the particle sizes, their contiguities, and of Co binder hardness and mean free paths, and in total, the volume fraction of constituents. A connection is made here between the composite material properties, especially including the material fracture toughness, and the several materials-type considerations of: (1 related hardness stress-strain behaviors; (2 dislocation (viscoplastic thermal activation characterizations; (3 Hall-Petch type reciprocal square root of particle or grain size dependencies; and (4 indentation and conventional fracture mechanics results. Related behaviors of MgO and Al2O3 crystal and polycrystal materials are also described for the purpose of making comparisons.

  13. Prediction of binary hard-sphere crystal structures.

    Science.gov (United States)

    Filion, Laura; Dijkstra, Marjolein

    2009-04-01

    We present a method based on a combination of a genetic algorithm and Monte Carlo simulations to predict close-packed crystal structures in hard-core systems. We employ this method to predict the binary crystal structures in a mixture of large and small hard spheres with various stoichiometries and diameter ratios between 0.4 and 0.84. In addition to known binary hard-sphere crystal structures similar to NaCl and AlB2, we predict additional crystal structures with the symmetry of CrB, gammaCuTi, alphaIrV, HgBr2, AuTe2, Ag2Se, and various structures for which an atomic analog was not found. In order to determine the crystal structures at infinite pressures, we calculate the maximum packing density as a function of size ratio for the crystal structures predicted by our GA using a simulated annealing approach. PMID:19518387

  14. Tribological characterization of hard coating film for elliptical surface peak

    International Nuclear Information System (INIS)

    The hard coating film on optical devices are the major methods to control wear and friction for industrial applications. This paper used fractal characteristics of surface topography such as elliptic ratio of surface roughness, coating hardness, and surface energy to build microcontact model of rough surface, in order to research contact behaviors between elliptical surfaces. Results of analysis showed that increased elliptic ratio, soft coating and adhesive force caused increase of contact area. When fractal roughness parameter and external force decreased, the true contact area also increased. When adhesive force remained unchanged, the increase of hardness value coefficient value resulted in the increase of true contact area. True contact area also increased as the fractal dimension increased from 1.1, and reached its maximum when fractal dimension reached 1.7, but would decreased when fractal dimension continued to increase. Such critical fractal dimension was affected by external force, fractal roughness coefficient and material characteristics.

  15. The hard x-ray spectrum of SN 1987A

    International Nuclear Information System (INIS)

    The authors report the discovery of hard x-rays in the energy range from 20 to 350 keV. The hard x-rays were first observed on August 10, 1987 and thereafter SN 1987A became the main target of the observatory. The measured spectrum is extremely hard. At high energies the photon spectrum has a power law index of ∼ 1.4. At lower energies the spectrum becomes flatter and there is indication of a cut-off below 25 keV. The luminosity in the above energy band is ∼ 2 x 1038 erg/s. The flux shows little variation between August 10 and beginning of October

  16. Unbeamed tidal disruption events at hard X-rays

    Science.gov (United States)

    Hryniewicz, K.; Walter, R.

    2016-02-01

    Context. Owing to their thermal emission, tidal disruption events (TDEs) were regularly detected in the soft X-rays and sometimes in the optical. Only a few TDEs have been detected at hard X-rays: two are high redshift beamed events, one of which occurred at the core of a nearby galaxy, and the most recent one is of a different nature, involving a compact object in the Milky Way. Aims: The aims of this work are to obtain a first sample of hard X-ray-selected unbeamed TDEs, to determine their frequency and to probe whether TDEs usually or exceptionally emit at hard X-ray energies. Methods: We performed extensive searches for hard X-ray flares at positions in over 53 000 galaxies, up to a distance of 100 Mpc in the Swift/BAT archive. Light curves were extracted and parametrized. The quiescent hard X-ray emission was used to exclude persistently active galactic nuclei. Significant flares from non-active galaxies were derived and checked for possible contamination. Results: We found a sample of nine TDE candidates, which translates into a rate of 2 × 10-5 galaxy-1 yr-1 above the BAT detection limit. This rate is consistent with those observed by XMM-Newton at soft X-rays and in the optical from SDSS observations, and is as expected from simulations. We conclude that hard X-ray emission should be ubiquitous in un-beamed TDEs and that electrons should be accelerated in their accretion flow.

  17. A synthetic dataset for evaluating soft and hard fusion algorithms

    Science.gov (United States)

    Graham, Jacob L.; Hall, David L.; Rimland, Jeffrey

    2011-06-01

    There is an emerging demand for the development of data fusion techniques and algorithms that are capable of combining conventional "hard" sensor inputs such as video, radar, and multispectral sensor data with "soft" data including textual situation reports, open-source web information, and "hard/soft" data such as image or video data that includes human-generated annotations. New techniques that assist in sense-making over a wide range of vastly heterogeneous sources are critical to improving tactical situational awareness in counterinsurgency (COIN) and other asymmetric warfare situations. A major challenge in this area is the lack of realistic datasets available for test and evaluation of such algorithms. While "soft" message sets exist, they tend to be of limited use for data fusion applications due to the lack of critical message pedigree and other metadata. They also lack corresponding hard sensor data that presents reasonable "fusion opportunities" to evaluate the ability to make connections and inferences that span the soft and hard data sets. This paper outlines the design methodologies, content, and some potential use cases of a COIN-based synthetic soft and hard dataset created under a United States Multi-disciplinary University Research Initiative (MURI) program funded by the U.S. Army Research Office (ARO). The dataset includes realistic synthetic reports from a variety of sources, corresponding synthetic hard data, and an extensive supporting database that maintains "ground truth" through logical grouping of related data into "vignettes." The supporting database also maintains the pedigree of messages and other critical metadata.

  18. Liquid money or hard cash? Drowning into granular material

    CERN Document Server

    Bagnoli, Franco

    2016-01-01

    In British English, the term "hard cash" refers to the form of payment using coins or bill, rather than cheques or credit or money transfer. In American English, it is often prefixed by the adjective "cold". On the contrary, in Italian the equivalent expression "denaro liquido" can be literary translated as "liquid money". In French the expression is equivalent with the additional factor, with respect to the rest of this discussion, that money becomes "argent". We have therefore two very different points of view: Is money hard and cold, or rather liquid and "jingling" ("moneta sonante")? As usual, we shall investigate this topic starting from some comics about the duck family.

  19. Tile-Packing Tomography Is NP-hard

    DEFF Research Database (Denmark)

    Chrobak, Marek; Dürr, Christoph; Guíñez, Flavio;

    2010-01-01

    Discrete tomography deals with reconstructing finite spatial objects from their projections. The objects we study in this paper are called tilings or tile-packings, and they consist of a number of disjoint copies of a fixed tile, where a tile is defined as a connected set of grid points. A row...... (its width or height is 1), while for some other types of tiles \\mathbbNPNP -hardness results have been shown in the literature. In this paper we present a complete solution to this question by showing that the problem remains \\mathbbNPNP -hard for all tiles other than bars....

  20. Hard X-ray variability of AGN observed with Suzaku

    International Nuclear Information System (INIS)

    Study of time variable spectra is independent tool to decompose the spectral components in the AGN (Active Galactic Nucleus); direct nuclear emission and reflection component. Since the difference between these two components becomes clear by comparing the behavior below and above 10 keV, hard X-ray study of time variability of AGNs is very important. Here we report the initial results of studies of hard X-ray variability of AGNs (MCG-6-30-15, MCG-5-23-16, NGC 4388, NGC 3516) observed with Suzaku. RMS spectra and flux-flux correlation above 10 keV is derived and discussed. (author)

  1. Planarization of topography with spin-on carbon hard mask

    Science.gov (United States)

    Noya, Go; Hama, Yusuke; Ishii, Maki; Nakasugi, Shigemasa; Kudo, Takanori; Padmanaban, Munirathna

    2016-03-01

    Spin-on-carbon hard mask (SOC HM) has been used in semiconductor manufacturing since 45nm node as an alternative carbon hard mask process to chemical vapor deposition (CVD). As advancement of semiconductor to 2X nm nodes and beyond, multiple patterning technology is used and planarization of topography become more important and challenging ever before. In order to develop next generation SOC, one of focuses is planarization of topography. SOC with different concepts for improved planarization and the influence of thermal flow temperature, crosslink, film shrinkage, baking conditions on planarization and filling performance are described in this paper.

  2. X-ray microscopy of soft and hard human tissues

    Energy Technology Data Exchange (ETDEWEB)

    Müller, Bert, E-mail: bert.mueller@unibas.ch; Schulz, Georg, E-mail: georg.schulz@unibas.ch; Deyhle, Hans, E-mail: hans.deyhle@unibas.ch; Stalder, Anja K., E-mail: anja.stalder@unibas.ch; Ilgenstein, Bernd, E-mail: bernd.ilgenstein@unibas.ch; Holme, Margaret N., E-mail: m.holme@imperial.ac.uk; Hieber, Simone E., E-mail: simone.hieber@unibas.ch [Biomaterials Science Center (BMC), University of Basel, c/o University Hospital, 4031 Basel (Switzerland); Weitkamp, Timm, E-mail: weitkamp@synchrotron-soleil.fr [Beamline ANATOMIX, Synchrotron Soleil, L’Orme des Merisiers, Saint Aubin - B.P. 48, 91192 Gif sur Yvette (France); Beckmann, Felix, E-mail: felix.beckmann@hzg.de [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht, c/o HZG at DESY, Notkestr. 85, 22607 Hamburg (Germany)

    2016-01-28

    The simultaneous post mortem visualization of soft and hard tissues using absorption-based CT remains a challenge. If the photon energy is optimized for the visualization of hard tissue, the surrounding soft tissue components are almost X-ray transparent. Therefore, the combination with other modalities such as phase-contrast CT, magnetic resonance microscopy, and histology is essential to detect the anatomical features. The combination of the 2D and 3D data sets using sophisticated segmentation and registration tools allows for conclusions about otherwise inaccessible anatomical features essential for improved patient treatments.

  3. Dispersion relations and subtractions in hard exclusive processes

    CERN Document Server

    Anikin, I V

    2007-01-01

    We study analytical properties of the hard exclusive processes amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss $D$-term. The relation of this constant to the fixed pole contribution found by Brodsky, Close and Gunion and defined by parton distributions is proved, while its manifestation is spoiled by the small $x$ divergence. The continuation to the real photons limit is considered and the numerical correspondence between lattice simulations of $D$-term and low energy Thomson amplitude is found.

  4. Development of a radiation-hard photomultiplier tube

    Science.gov (United States)

    Birnbaum, M. M.; Bunker, R. L.; Roderick, J.; Stephenson, K.

    1984-01-01

    In a radiation-hard photomultiplier tube (PMT) such as has been developed for stabilization of the Galileo spacecraft as it goes through the Jovian high energy radiation belts, the primary effects of high energy electron and proton radiation that must be resisted are the production of fluorescence and Cerenkov emission. The present PMT envelope is ceramic rather than glass, and employs a special, electron-focusing design which will collect, accelerate and amplify electrons only from desired photocathode areas. Tests in a Co-60 radiation facility have shown that the radiation-hard PMT produces less than 2.5 percent of the radiation noise of a standard PMT.

  5. How to plan ahead for hard times in business

    OpenAIRE

    Adeleke, Taiwo Adekunle

    2011-01-01

    The topic was actually picked to device or proffer effective solution on how to deal with or tackle hard times when one is about to establish a business. However, I discovered that man-agement seems to over look the issue of hard times in day to day running of a business. They should remember that the only thing that will aid and assist a business to forge ahead is when there are proper and adequate strategies. These strategies must be followed incessantly in order to overcome any eventua...

  6. X-ray microscopy of soft and hard human tissues

    International Nuclear Information System (INIS)

    The simultaneous post mortem visualization of soft and hard tissues using absorption-based CT remains a challenge. If the photon energy is optimized for the visualization of hard tissue, the surrounding soft tissue components are almost X-ray transparent. Therefore, the combination with other modalities such as phase-contrast CT, magnetic resonance microscopy, and histology is essential to detect the anatomical features. The combination of the 2D and 3D data sets using sophisticated segmentation and registration tools allows for conclusions about otherwise inaccessible anatomical features essential for improved patient treatments

  7. Monitoring of hard turning using acoustic emission signal

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskaran, J.; Murugan, M. [B.S. Abdur Rahman University, Chennai (India); Balashanmugam, N.; Chellamalai, M. [Central Manufacturing Technology Institute, Bangalore (India)

    2012-02-15

    Monitoring of tool wear during hard turning is essential. Many investigators have analyzed the acoustic emission (AE) signals generated during machining to understand the metal cutting process and for monitoring tool wear and failure. In the current study on hard turning, the skew and kurtosis parameters of the root mean square values of AE signal (AERMS) are used to monitor tool wear. The rubbing between the tool and the workpiece increases as the tool wear crosses a threshold, thereby shifting the mass of AERMS distribution to right, leading to a negative skew. The increased rubbing also led to a high kurtosis value in the AERMS distribution curve.

  8. Prospects for supermirrors in hard x-ray spectroscopy

    DEFF Research Database (Denmark)

    Joensen, Karsten D.; Gorenstein, Paul; Christensen, Finn Erland; Hoghoj, Peter; Ziegler, Eric; Susini, Jean; Freund, Andreas K.; Siddons, D.P.; Wood, James L.

    1994-01-01

    reflectivity for x rays. For hard x rays (≥ 15 keV), the absorption, however, is low enough that it is possible to design supermirrors with 10 - 70% reflectivity in a band ≈ 3 times the width of the total reflection regime. Supermirrors of W/Si and Ni/C have been successfully fabricated and characterized. The...... measured x-ray reflectivities are well accounted for by the standard dynamical theories of multilayer reflection. Hard x ray applications that could benefit from x-ray supermirror coatings include focusing and imaging instrumentation for astrophysics, collimating and focusing devices for synchrotron...

  9. The effect of hard coal density on its flotation performance

    OpenAIRE

    Ewa Małysa

    2005-01-01

    Hard coal flotation depends on many factors, one of which is the density of the grains floated. The heavier the grain, the greater the gravitational force that counteracts the force of adhesion between the grain and an air bubble, and the lower the probability of forming the grain-air bubble aggregate. This paper presents the results of a study on the effect of grain density on hard coal flotation. To eliminate the effect of grain size, densimetric fractions of very similar grain sizes were f...

  10. Effect of coatings on hardness of commercial marbles

    Science.gov (United States)

    Zedef, Veysel

    2016-04-01

    In this study, three type of marble and one granite were chosen to understand if the coating is effective on hardness of the commercial rocks. To understand the hardness of the rock, Schmidt hammer tests were undertaken. The used device allowed us uniaxial compressive strength (UCS) as well as Schmidt rebound (R). The coated samples have clearly high R and UCS values when compared to uncoated samples. The Elazig visne, the well-known marble of Turkey, have 35.6 R and 44.2 MPa UCS values of coated samples. On the other hand, uncoated surface of the same marble have 30.5 R and 35.4 MPa UCS.

  11. Hard single diffractive jet production at D0

    International Nuclear Information System (INIS)

    Preliminary results from the D null experiment on jet production with forward rapidity gaps in p anti p collisions are presented. A class of dijet events with a forward rapidity gap is observed at center-of-mass energies √s = 1800 GeV and 630 GeV. The number of events with rapidity gaps at both center-of-mass energies is significantly greater than the expectation from multiplicity fluctuations and is consistent with a hard single diffractive process. A small class of events with two forward gaps and central dijets is also observed at 1800 GeV. This topology is consistent with hard double pomeron exchange

  12. Soft Copy versus Hard Copy Reading in Digital Mammography

    OpenAIRE

    Obenauer, Silvia; Hermann, Klaus-Peter; Marten, Katharina; Luftner-Nagel, Susanne; von Heyden, Dorit; Skaane, Per; Grabbe, Eckhardt

    2003-01-01

    The objective of this study was to compare soft copy reading at a mammography work station with hard copy reading of full-field digital mammographic images. Mammograms of 60 patients (n = 29 malignant, n = 31 benign) performed with full-field digital mammography (Senographe 2000D, GE, Buc, France) were evaluated. Reading was performed based on hard copy prints (Scopix, Agfa, Leverkusen, Germany) and on 2 k × 2.5 k high-resolution monitors (Sun Ultra 60, Sun Microsystems, Palo Alto, California...

  13. A hard X-ray laboratory for monochromator characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Hamelin, B. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Since their installation at ILL during the 1970`s the ILL {gamma}-ray diffractometers have been intensively used in the development of neutron monochromators. However, the ageing of the sources and new developments in hard X-ray diffractometry lead to a decision at the end of 1995 to replace the existing {gamma}-ray laboratory with a hard X-ray laboratory, based on a 420 keV generator, making available in the long term several beam-lines for rapid characterisation of monochromator crystals. The facility is now installed and its characteristics and advantages are outlined. (author). 2 refs.

  14. Medium Induced Transverse Momentum Broadening in Hard Processes

    CERN Document Server

    Mueller, A H; Xiao, Bo-Wen; Yuan, Feng

    2016-01-01

    Using deep inelastic scattering on a large nucleus as an example, we consider the transverse momentum broadening of partons in hard processes in the presence of medium. We find that one can factorize the vacuum radiation contribution and medium related $P_T$ broadening effects into the Sudakov factor and medium dependent distributions, respectively. Our derivations can be generalized to other hard processes, such as dijet productions, which can be used as a probe to measure the medium $P_T$ broadening effects in heavy ion collisions when Sudakov effects are not overwhelming.

  15. Packing Effect of Excluded Volume on Hard-Sphere Colloids

    Institute of Scientific and Technical Information of China (English)

    肖长明; 金国钧; 马余强

    2001-01-01

    We apply the principle of maximum entropy to consider the excluded volume effect on the phase separation of binary mixtures consisting of hard spheres with two different diameters. We show that a critical volume fraction of hard spheres exists locating the packing of large spheres. In particular, through numerical calculation, we have found that the critical volume fraction becomes lower when the ratio α = σ1/σ2 of large-to-small sphere diameters increases, but becomes higher when the ratio of the large sphere volume fraction to the total volume fraction of large and small spheres increases.

  16. Hard and Heavy Music: Can It Make a Difference in the Young Cancer Patients' Life?

    OpenAIRE

    Fereshteh Ahmadi

    2009-01-01

    The aim of the present article is to discuss the role hard and heavy music plays in coping with cancer. Here, hard and heavy music refers to genres such as heavy metal, hard rock, hard rap, punk rock and aggressive pop music.

  17. Hard and Heavy Music: Can It Make a Difference in the Young Cancer Patients' Life?

    Directory of Open Access Journals (Sweden)

    Fereshteh Ahmadi

    2009-07-01

    Full Text Available The aim of the present article is to discuss the role hard and heavy music plays in coping with cancer. Here, hard and heavy music refers to genres such as heavy metal, hard rock, hard rap, punk rock and aggressive pop music.

  18. Short-term hot hardness characteristics of rolling-element steels

    Science.gov (United States)

    Chevalier, J. L.; Dietrich, M. W.; Zaretsky, E. V.

    1972-01-01

    Short-term hot hardness studies were performed with five vacuum-melted steels at temperatures from 294 to 887 K (70 to 1140 F). Based upon a minimum Rockwell C hardness of 58, the temperature limitation on all materials studied was dependent on the initial room temperature hardness and the tempering temperature of each material. For the same room temperature hardness, the short-term hot hardness characteristics were identical and independent of material composition. An equation was developed to predict the short-term hardness at temperature as a function of initial room temperature hardness for AISI 52100, as well as the high-speed tool steels.

  19. Phase behaviour of hard spheres confined between parallel hard plates: manipulation of colloidal crystal structures by confinement

    International Nuclear Information System (INIS)

    We study the phase behaviour of hard spheres confined between two parallel hard plates using extensive computer simulations. We determine the full equilibrium phase diagram for arbitrary densities and plate separations from one to five hard-sphere diameters using free energy calculations. We find a first-order fluid-solid transition, which corresponds to either capillary freezing or melting depending on the plate separation. The coexisting solid phase consists of crystalline layers with either triangular (Δ) or square (□) symmetry. Increasing the plate separation, we find a sequence of crystal structures from ..nΔ →(n+1) □→(n+1) Δ..., where n is the number of crystal layers, in agreement with experiments on colloids. At high densities, the transition between square to triangular phases is interrupted by intermediate structures, e.g., prism, buckled, and rhombic phases. (letter to the editor)

  20. Uniform shear flow in dissipative gases. Computer simulations of inelastic hard spheres and (frictional) elastic hard spheres

    OpenAIRE

    Astillero, A.; Santos, A.

    2005-01-01

    In the preceding paper (cond-mat/0405252), we have conjectured that the main transport properties of a dilute gas of inelastic hard spheres (IHS) can be satisfactorily captured by an equivalent gas of elastic hard spheres (EHS), provided that the latter are under the action of an effective drag force and their collision rate is reduced by a factor $(1+\\alpha)/2$ (where $\\alpha$ is the constant coefficient of normal restitution). In this paper we test the above expectation in a paradigmatic no...

  1. NuSTAR Hard X-ray Optics

    DEFF Research Database (Denmark)

    Koglin, Jason E.; Christensen, Finn Erland; Craig, William W.;

    2005-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) is a small explorer (SMEX) mission currently under an extended Phase A study by NASA. NuSTAR will be the first satellite mission to employ focusing optics in the hard X-ray band (8- 80 keV). Its design eliminates high detector backgrounds, allows...

  2. Glass transition of dense fluids of hard and compressible spheres.

    Science.gov (United States)

    Berthier, Ludovic; Witten, Thomas A

    2009-08-01

    We use computer simulations to study the glass transition of dense fluids made of polydisperse repulsive spheres. For hard particles, we vary the volume fraction, phi , and use compressible particles to explore finite temperatures, T>0 . In the hard sphere limit, our dynamic data show evidence of an avoided mode-coupling singularity near phi(MCT) is approximately 0.592; they are consistent with a divergence of equilibrium relaxation times occurring at phi(0) is approximately 0.635, but they leave open the existence of a finite temperature singularity for compressible spheres at volume fraction phi>phi(0). Using direct measurements and a scaling procedure, we estimate the equilibrium equation of state for the hard sphere metastable fluid up to phi(0), where pressure remains finite, suggesting that phi(0) corresponds to an ideal glass transition. We use nonequilibrium protocols to explore glassy states above phi(0) and establish the existence of multiple equations of state for the unequilibrated glass of hard spheres, all diverging at different densities in the range phi in [0.642, 0.664]. Glassiness thus results in the existence of a continuum of densities where jamming transitions can occur. PMID:19792128

  3. Development of radiation hard components for remote maintenance

    International Nuclear Information System (INIS)

    In International Thermonuclear Experimental Reactor (ITER), in-vessel remote-handling is inevitably required to assemble and maintain activated in-vessel components due to D-T operation. The components of the in-vessel remote-handling system must have sufficient radiation hardness to allow for operation under an intense gamma-ray radiation of over 30 kGy/h for periods up to more than 1,000 hours. To this end, extensive irradiation tests and quality improvements including the optimization of material composition have been conducted through the ITER R and D program in order to develop radiation hard components which satisfy radiation doses from 10 MGy to 100 MGy at the dose rate of 10 kGy/h. This paper outlines the latest status of the radiation hard component development that has been conducted as the Japan Home Team's contribution to ITER. The remote-handling components tested are categorized into either robotics, viewing systems or common components. The irradiation tests include commercial base products for screening both modified and newly developed products to improve their radiation hardness. (author)

  4. Development of radiation hardness components for ITER remote maintenance

    International Nuclear Information System (INIS)

    In the ITER, in-vessel remote handling is required to assemble and maintain in-vessel components in DT operations. Since in-vessel remote handling systems must operate under intense gamma ray radiation exceeding 30 kGy/h, their components must have sufficiently high radiation hardness to allow maintenance long enough in ITER in-vessel environments. Thus, extensive radiation tests and quality improvement, including optimization of material compositions, have been conducted through the ITER R and D program to develop radiation hardness components that meet radiation doses from 10 to 100 MGy at 10 kGy/h. This paper presents the latest on radiation hardness component development conducted by the Japan Home Team as a contribution to the ITER. The remote handling components tested are categorized for use in robotic or viewing systems, or as common components. Radiation tests have been conducted on commercially available products for screening, on modified products, and on new products to improve the radiation hardness. (author)

  5. Transport properties of the Fermi hard-sphere system

    CERN Document Server

    Mecca, Angela; Benhar, Omar; Polls, Artur

    2015-01-01

    The transport properties of neutron star matter play an important role in a variety of astrophysical processes. We report the results of a calculation of the shear viscosity and thermal conductivity coefficients of the hard-sphere fermion system of degeneracy $\

  6. Registration of ‘Joe’ hard white winter wheat

    Science.gov (United States)

    ‘Joe’, a hard white winter wheat (Triticum aestivum L.) was developed at the Agricultural Research Center-Hays, Kansas State University and released by the Kansas Agricultural Experiment Station in 2015. Joe was selected from a two-way cross of KS04HW101-3/KS04HW119-3 made in 2005 at Hays, KS. The ...

  7. The nature of the hard state of Cygnus X-3

    CERN Document Server

    Hjalmarsdotter, L; Larsson, S; Beckmann, V; McCollough, M; Hannikainen, D C; Vilhu, O

    2007-01-01

    The X-ray binary Cygnus X-3 is a highly variable X-ray source that displays a wide range of observed spectral states. One of the main states is significantly harder than the others, peaking at ~ 20 keV, with only a weak low-energy component. Due to the enigmatic nature of this object, hidden inside the strong stellar wind of its Wolf-Rayet companion, it has remained unclear whether this state represents an intrinsic hard state, with truncation of the inner disc, or whether it is just a result of increased local absorption. We study the X-ray light curves from RXTE/ASM and CGRO/BATSE in terms of distributions and correlations of flux and hardness and find several signs of a bimodal behaviour of the accretion flow that are not likely to be the result of increased absorption in a surrounding medium. Using INTEGRAL observations, we model the broad-band spectrum of Cyg X-3 in its apparent hard state. We find that it can be well described by a model of a hard state with a truncated disc, despite the low cut-off ene...

  8. Registration of 'NE01481' hard red winter wheat

    Science.gov (United States)

    'NE01481' (Reg. No. PI 659689) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in April, 2010. Nebraska wheat growers, in addition to superior agronomic performance, would like to have increased r...

  9. Neuroscientists Find Learning Is Not "Hard-Wired"

    Science.gov (United States)

    Sparks, Sarah D.

    2012-01-01

    Neuroscience exploded into the education conversation more than 20 years ago, in step with the evolution of personal computers and the rise of the Internet, and policymakers hoped medical discoveries could likewise help doctors and teachers understand the "hard wiring" of the brain. That conception of how the brain works, exacerbated by the…

  10. Approximation algorithms and hardness of approximation for knapsack problems

    NARCIS (Netherlands)

    Buhrman, H.; Loff, B.; Torenvliet, L.

    2012-01-01

    We show various hardness of approximation algorithms for knapsack and related problems; in particular we will show that unless the Exponential-Time Hypothesis is false, then subset-sum cannot be approximated any better than with an FPTAS. We also give a simple new algorithm for approximating knapsac

  11. Prospects for supermirrors in hard x-ray spectroscopy

    DEFF Research Database (Denmark)

    Joensen, Karsten D.; Gorenstein, Paul; Christensen, Finn Erland;

    1994-01-01

    measured x-ray reflectivities are well accounted for by the standard dynamical theories of multilayer reflection. Hard x ray applications that could benefit from x-ray supermirror coatings include focusing and imaging instrumentation for astrophysics, collimating and focusing devices for synchrotron...

  12. Mainstream teachers about including deaf or hard of hearing students

    NARCIS (Netherlands)

    Vermeulen, J.A.; Denessen, E.J.P.G.; Knoors, H.E.T.

    2012-01-01

    This study is aimed at teachers’ classroom practices and their beliefs and emotions regarding the inclusion of deaf or hard of hearing (d/hh) students in mainstream secondary schools. Nine teachers in two schools were interviewed about the inclusion of d/hh students. These teachers were found to con

  13. Studying plasticity in hard and soft Nb-Co intermetallics

    International Nuclear Information System (INIS)

    It is shown that micropillar compression can be used to study the plastic flow behavior of both a hard, brittle cubic Laves phase, NbCo2, and a related monoclinic compound, Nb2Co7, which is known to be softer, but is also brittle and has, so far, only been prepared in a fine-grained form. Flow in the Laves phase occurs at a shear stress of 3.1 GPa on the left angle 0 anti 1 anti 1 right angle {111} slip system, consistent with previous observations and estimates from hardness measurement. Micropillar compression and electron microscopy of single crystals of Nb2Co7 indicates that flow takes place parallel to the (001) plane, with left angle 100 right angle and left angle 110 right angle type Burgers vectors, at a critical resolved shear stress between 0.1 and 0.5 GPa. It is shown that this is much less than predicted by hardness measurements, consistent with the idea that the hardness of plastically anisotropic materials is determined by flow on the hardest operating slip system. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Component mixers and a hardness result for counterfeiting quantum money

    CERN Document Server

    Lutomirski, Andrew

    2011-01-01

    In this paper we give the first proof that, under reasonable assumptions, a problem related to counterfeiting quantum money from knots [Farhi et al. 2010] is hard. Along the way, we introduce the concept of a component mixer, define three new classical query problems and associated complexity classes related to graph isomorphism and group membership, and conjecture an oracle separating QCMA from QMA.

  15. Abuse of Children Who Are Deaf or Hard of Hearing.

    Science.gov (United States)

    Steer, Michael

    1998-01-01

    Discusses societal reasons for the abuse of children who are deaf or hard of hearing. Suggests some solutions that are linked to current professional literature and thinking on international disability policy. These include reliable nationwide data on abuse, training about abuse for all personnel who work with children who have disabilities, and…

  16. The Hard of Hearing Child: Clinical and Educational Management.

    Science.gov (United States)

    Berg, Frederick S., Ed.; Fletcher, Samuel G., Ed.

    The chapters by various specialists presenting information on the aurally handicapped child and his clinical and educational management are divided into three sections. The brief introductory section presents an overview of the work to follow, defines the hard of hearing child, describes his prevalence, and traces the locus of educational programs…

  17. Compressive strength and hardness of metal matrix syntactic foams

    International Nuclear Information System (INIS)

    Six types of metal matrix syntactic foams (MMSFs) were produced by pressure infiltration technique. The foams were investigated by upsetting tests at increased (2200C) and at room (250C) temperature. The parameters were the constituents of the composites and the aspect ratio (height-diameter ratio, H/D) of the specimens. The characteristic properties were: the compressive strength, the fracture strain, the structural stiffness of the foams and the absorbed energy. The strength, the strain and the energy were decreased while the stiffness was increased by increasing the H/D. Increased temperature caused ∼25 % drop in the strength and in the stiffness. Macrohardness, depth sensitive and dynamic hardness tests were also performed on MMSF blocks: macrohardness is a structural property and independent from the matrix material. The depth sensitive hardness is sensitive to the deformation capability of the matrix and to a possible change reaction. The dynamic hardnesses of the MMSFs were higher than the hardness of the matrices and this is a microballoon related property.

  18. GRB 060313: A New Paradigm for Short-Hard Bursts?

    CERN Document Server

    Roming, P W A; Palshin, V D; Pagani, C; Norris, J; Kumar, P; Krimm, H; Holland, S T; Gronwall, C; Blustin, A J; Zhang, B; Schady, P; Sakamoto, T; Osborne, J P; Nousek, J A; Marshall, F E; Mészáros, P; Golenetskii, S V; Gehrels, N; Frederiks, D D; Campana, S; Burrows, D N; Boyd, P T; Barthelmy, S; Aptekar, R L; Roming, Peter W. A.; Berk, Daniel Vanden; Palshin, Valentin; Pagani, Claudio; Norris, Jay; Kumar, Pawan; Krimm, Hans; Holland, Stephen T.; Gronwall, Caryl; Zhang, Bing; Schady, Patricia; Sakamoto, Takanori; Osborne, Julian P.; Nousek, John A.; Marshall, Frank E.; Meszaros, Peter; Golenetskii, Sergey V.; Gehrels, Neil; Frederiks, Dmitry D.; Campana, Sergio; Burrows, David N.; Boyd, Patricia T.; Barthelmy, Scott

    2006-01-01

    We report the simultaneous observations of the prompt emission in the gamma-ray and hard X-ray bands by the Swift-BAT and the KONUS-Wind instruments of the short-hard burst, GRB 060313. The observations reveal multiple peaks in both the gamma-ray and hard X-ray suggesting a highly variable outflow from the central explosion. We also describe the early-time observations of the X-ray and UV/Optical afterglows by the Swift XRT and UVOT instruments. The combination of the X-ray and UV/Optical observations provide the most comprehensive lightcurves to date of a short-hard burst at such an early epoch. The afterglows exhibit complex structure with different decay indices and flaring. This behavior can be explained by the combination of a structured jet, radiative loss of energy, and decreasing microphysics parameters occurring in a circum-burst medium with densities varying by a factor of approximately two on a length scale of 10^17 cm. These density variations are normally associated with the environment of a mass...

  19. QUANTUM HALL EFFECT OF HARD-CORE BOSONS

    OpenAIRE

    Jain, J. K.; Rao, Sumathi

    1995-01-01

    Motivated by a mean-field approach, which has been employed for anyon superfluidity and the fractional quantum Hall effect, the quantum Hall effect (QHE) of hard-core bosons is investigated. It is shown that QHE is possible {\\em only} in the thermodynamic limit. The filling factors where QHE may be expected are obtained with the help of two adiabatic schemes.

  20. Shaping Smoking Cessation in Hard-to-Treat Smokers

    Science.gov (United States)

    Lamb, R. J.; Kirby, Kimberly C.; Morral, Andrew R.; Galbicka, Greg; Iguchi, Martin Y.

    2010-01-01

    Objective: Contingency management (CM) effectively treats addictions by providing abstinence incentives. However, CM fails for many who do not readily become abstinent and earn incentives. Shaping may improve outcomes in these hard-to-treat (HTT) individuals. Shaping sets intermediate criteria for incentive delivery between the present behavior…

  1. Increasing the hardness of tool steels by plasma hardening

    International Nuclear Information System (INIS)

    In this work, investigations were carried out into the structure, hardness, cracking resistance parameters (impact toughness, dynamic stress intensity factor Kld) and the nature of failure in dynamic loading 75Kh2MF steel in combined induction-plasma hardening and the results were compared with HF quenching and plasma treatment in the initial (normalised) condition

  2. The Tonya Harding Controversy: An Analysis of Image Restoration Strategies.

    Science.gov (United States)

    Benoit, William L.; Hanczor, Robert S.

    1994-01-01

    Analyzes Tonya Harding's defense of her image in "Eye to Eye with Connie Chung," applying the theory of image restoration discourse. Finds that the principal strategies employed in her behalf were bolstering, denial, and attacking her accuser, but that these strategies were not developed very effectively in this instance. (SR)

  3. Hard scattering and jet physics in connection with real photons

    International Nuclear Information System (INIS)

    This report contains a summary of the physics discussed in the working groups on (a) jet physics at the SPS in hadron-hadron collisions, (b) hard scattering with incident real photons and (c) large psub(T) prompt photons in hadron-hadron collisions. (orig.)

  4. Mechanics of an Asymmetric Hard-Soft Lamellar Nanomaterial.

    Science.gov (United States)

    Shi, Weichao; Fredrickson, Glenn H; Kramer, Edward J; Ntaras, Christos; Avgeropoulos, Apostolos; Demassieux, Quentin; Creton, Costantino

    2016-02-23

    Nanolayered lamellae are common structures in nanoscience and nanotechnology, but most are nearly symmetric in layer thickness. Here, we report on the structure and mechanics of highly asymmetric and thermodynamically stable soft-hard lamellar structures self-assembled from optimally designed PS1-(PI-b-PS2)3 miktoarm star block copolymers. The remarkable mechanical properties of these strong and ductile PS (polystyrene)-based nanomaterials can be tuned over a broad range by varying the hard layer thickness while maintaining the soft layer thickness constant at 13 nm. Upon deformation, thin PS lamellae (100 nm) manifests cavitation in both soft and hard nanolayers. In situ tensile-SAXS experiments revealed the evolution of cavities during deformation and confirmed that the damage in such systems reflects both plastic deformation by shear and residual cavities. The aspects of the mechanics should point to universal deformation behavior in broader classes of asymmetric hard-soft lamellar materials, whose properties are just being revealed for versatile applications. PMID:26760051

  5. Innervation of the hard palate of the rat

    NARCIS (Netherlands)

    Liem, Swie Bing

    1989-01-01

    This study is undertaken to gain more insight into the pattern of innervation of the hard palate of the rat and into the morphology of the sensory structures found there. Since the main research project of the Department of Neurobiology and Oral Physiology is dedicated to the formulation of a model

  6. Nano-hardness estimation by means of Ar+ ion etching

    International Nuclear Information System (INIS)

    When the coatings are in nano-scale, the mechanical properties cannot be easily estimated by means of the conventional methods due to: tip shape, instrument resolution, roughness, and substrate effect. In this paper, we proposed a semi-empirical method to evaluate the mechanical properties of thin films based on the sputtering rate induced by bombardment of Ar+ ion. The Ar+ ion bombardment was induced by ion gun implemented in Auger electron spectroscopy (AES). This procedure has been applied on a series of coatings with different structure (carbon films) and a series of coating with a different density (ZnO thin films). The coatings were deposited on Silicon substrates by RF sputtering plasma. The results show that, as predicted by Insepov et al., there is a correlation between hardness and sputtering rate. Using reference materials and a simple power law equation the estimation of the nano-hardness using an Ar+ beam is possible. - Highlights: • ZnO film and Carbon films were grown on silicon using PVD. • The growth temperature was room temperature. • The hardness of the coatings was estimated by means of nanoindentation. • Evaluation of resistance of materials to the mechanical damage induced by an Ar+ ion gun (AES). • The hardness have been studied and a power law with the erosion rate has been found

  7. Unitary formalism for scattering from a hard corrugated wall

    Science.gov (United States)

    Brown, G. C.; Celli, V.; Coopersmith, M.; Haller, M.

    1982-07-01

    We obtain two coupled integral equations for the diffraction of waves from a hard corrugated surface. This rearrangement is shown to be equivalent to the integral equation for the scattering amplitude obtained by an application of the Rayleigh method. The formalism presented here, analogous to K-matrix theory, makes the unitarity of the theory apparent at each stage of approximation.

  8. Crab Nebula Variations in Hard X-rays

    Science.gov (United States)

    Wilson-Hodge, Colleen A.

    2012-01-01

    The Crab Nebula was surprisingly variable from 2001-2010, with less variability before 2001 and since mid-2010. We presented evidence for spectral softening from RXTE, Swift/BAT, and Fermi GBM during the mid-2008-2010 flux decline. We see no clear connections between the hard X-ray variations and the GeV flares

  9. Rad-hard embedded computers for nuclear robotics

    International Nuclear Information System (INIS)

    Nuclear industries require robots with embedded rad hard electronics and high reliability. The SYROCO research program allowed to perform efficient industrial prototypes, build according to MICADO architecture, and to design CADMOS architecture. MICADO architecture uses the auto healing property that have CMOS circuits when being switched off during irradiation. (D.L.). 8 refs., 5 figs

  10. Hardness and thermal stability of cubic silicon nitride

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Kragh, Flemming; Frost, D. J.;

    2001-01-01

    The hardness and thermal stability of cubic spinel silicon nitride (c-Si3N4), synthesized under high-pressure and high-temperature conditions, have been studied by microindentation measurements, and x-ray powder diffraction and scanning electron microscopy, respectively The phase at ambient...

  11. Nanoindentation hardness of hot-pressed boron suboxide

    International Nuclear Information System (INIS)

    Highlights: → The load-displacement indentation response of hot-pressed B6O is measured and analysed. → The nanoindentation hardness of hot-pressed boron suboxide is reported. → An approach is developed to simulate multi-cycling loading load-displacement curves. → A comprehensive model inter-comparison study of the ISE in hot-pressed B6O is also presented. → The fractal dimension is a better measure of ISE than the Meyer's index. - Abstract: The existence of the indentation size effect implies the absence of a single hardness value for the material under investigation especially at low applied loads. In this paper we present an investigation of the indentation size dependence behaviour of nanoindentation hardness in boron suboxide ceramic compacts prepared by uniaxial hot-pressing. Berkovich nanohardness indentations were conducted and analyzed accordingly. In addition to the ordinary Oliver and Pharr method of nanoindentation data analysis, a quantitative approach for the loading curve analysis is proposed. Using the proposed approach, the description and characterization of the observed indentation size effect through the application of the Meyer's law, and the classical and the modified proportional specimen resistance models as well as the multi-fractal scaling law was conducted and is reported. The load-independent hardness values deduced from our quantitative approach are comparable to the results calculated with conventional methods, especially with the multi-fractal scaling law.

  12. Microstructural gradients in thin hard coatings -- tailor-made

    DEFF Research Database (Denmark)

    Pantleon, Karen; Oettel, Heinrich

    Microstructural modifications resulting from time dependent variations of the bias voltage during the deposition of thin hard coatings are discussed. TiN-coatings are produced by reactive magnetron sputtering in several modes: (a) stepwise increase of the bias voltage during the deposition, (b...

  13. How 5 Colleges Plan to Keep Growing in Hard Times

    Science.gov (United States)

    Masterson, Kathryn

    2009-01-01

    Momentum can stall in a time of diminished resources. For colleges on the fast track, leaders have shifted money around and made some hard choices to keep growing. The author reached out to five up-and-coming institutions to find out how they manage their ambitions during tough times. As many colleges instituted hiring freezes to save money,…

  14. HARD CHROME POLLUTION PREVENTION DEMONSTRATION PROJECT - INTERIM REPORT

    Science.gov (United States)

    In the project, five chromium emission prevention/control devices were tested tha cover the spectrum of prevention/control techniques currently in use in small- and large-size hard chromium electroplating job shops. The Project results show that some of the tested devices had ch...

  15. Attosecond Hard X-ray Free Electron Laser

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2013-03-01

    Full Text Available In this paper, several schemes of soft X-ray and hard X-ray free electron lasers (XFEL and their progress are reviewed. Self-amplified spontaneous emission (SASE schemes, the high gain harmonic generation (HGHG scheme and various enhancement schemes through seeding and beam manipulations are discussed, especially in view of the generation of attosecond X-ray pulses. Our recent work on the generation of attosecond hard X-ray pulses is also discussed. In our study, the enhanced SASE scheme is utilized, using electron beam parameters of an XFEL under construction at Pohang Accelerator Laboratory (PAL. Laser, chicane and electron beam parameters are optimized to generate an isolated attosecond hard X-ray pulse at 0.1 nm (12.4 keV. The simulations show that the manipulation of electron energy beam profile may lead to the generation of an isolated attosecond hard X-ray of 150 attosecond pulse at 0.1 nm.

  16. Imaging of reconnection processes in hard X-rays

    NARCIS (Netherlands)

    Svestka, Z.; Poletto, G.

    1984-01-01

    The Hard X-ray Spectrometer aboard the SMM detected several events of energy release late in the development of two-ribbon flares. One such event, at 21:12 UT on 21 May, 1980 ( 20 min after the flare onset and 15 min after the peak of the impulsive phase) is studied in detail. The site of new bright

  17. Solar hard X-rays and gamma-rays

    Institute of Scientific and Technical Information of China (English)

    甘为群; 常进; 李友平; 林春梅

    2002-01-01

    We briefly introduce our recent work on the spectral evolution of energetic protons, the beam property of accelerated electrons, the gamma-ray flare classification, the temporal features of the annihilation line, the hard X-ray delayed events, the hydrodynamic process, and the continuum emission in solar flares.

  18. Toughness enhancement in hard ceramic thin films by alloy design

    Directory of Open Access Journals (Sweden)

    H. Kindlund

    2013-10-01

    Full Text Available Hardness is an essential property for a wide range of applications. However, hardness alone, typically accompanied by brittleness, is not sufficient to prevent failure in ceramic films exposed to high stresses. Using VN as a model system, we demonstrate with experiment and density functional theory (DFT that refractory VMoN alloys exhibit not only enhanced hardness, but dramatically increased ductility. V0.5Mo0.5N hardness is 25% higher than that of VN. In addition, while nanoindented VN, as well as TiN reference samples, suffer from severe cracking typical of brittle ceramics, V0.5Mo0.5N films do not crack. Instead, they exhibit material pile-up around nanoindents, characteristic of plastic flow in ductile materials. Moreover, the wear resistance of V0.5Mo0.5N is considerably higher than that of VN. DFT results show that tuning the occupancy of d–t2g metallic bonding states in VMoN facilitates dislocation glide, and hence enhances toughness, via the formation of stronger metal/metal bonds along the slip direction and weaker metal/N bonds across the slip plane.

  19. Teaching Instrumental Music to Deaf and Hard of Hearing Students

    Science.gov (United States)

    Hash, Phillip M.

    2003-01-01

    Many Deaf/Hard of Hearing (D/HH) individuals have successfully participated in instrumental music programs for over 100 years. In spite of proven success, however, many directors are reluctant to involve students with hearing loss in school bands and orchestras. Reasons may include a lack of knowledge regarding the needs and capabilities of these…

  20. Superconductivity, electrons, and phonons in hard coating films

    International Nuclear Information System (INIS)

    This paper briefly outlines the basic features of superconductivity. It explains the significance of high transition temperatures Tc of some hard coating materials, and the method of calculating the phonon dispersion curves by means of the tight-binding theory. The results obtained for coating films made of NbC or NbN are presented. (DG)

  1. Cost of Forward Contracting Hard Red Winter Wheat

    OpenAIRE

    Townsend, John P.; Brorsen, B. Wade

    1997-01-01

    Two methods were used to estimate the cost of forward contracting hard red winter wheat. One hundred days before delivery, the estimated cost of forward contracting ranged from six cents/bu. To eight cents/bu. Thus, further evidence is provided that the cost of forward contracting grain is not zero.

  2. Dark Matter Detection with Hard X-ray Telescopes

    CERN Document Server

    Jeltema, Tesla E

    2011-01-01

    We analyze the impact of future hard X-ray observations on the search for indirect signatures of particle dark matter in large extragalactic systems such as nearby clusters or groups of galaxies. We argue that the hard X-ray energy band falls squarely at the peak of the inverse Compton emission from electrons and positrons produced by dark matter annihilation or decay for a large class of dark matter models. Specifically, the most promising are low-mass models with a hard electron-positron annihilation final state spectrum and intermediate-mass models with a soft electron-positron spectrum. We find that constraints on dark matter models similar to the current constraints from the Fermi Gamma-Ray Space Telescope will be close to the limit of the sensitivity of the near-term hard X-ray telescopes NuSTAR and ASTRO-H for relatively long observations, but an instrument similar to the Wide Field Imager proposed for the International X-ray Observatory would allow significant gains to be made. In the future, the abil...

  3. Hard coal subsidies: A never-ending story?

    International Nuclear Information System (INIS)

    In Germany, hard coal has been subsidized for almost half a century. Despite the declining significance of hard coal production for the domestic labor market, the subsidies have continued to increase until the middle of the last decade, reaching a peak at Euro 6.7 billion in 1996. While these subsidies have been continually shrinking since then, settling at Euro 2.7 billion in 2005, it is very likely that hard coal support will be extended in Germany well into the next decade and even beyond. This article questions the main arguments raised by the proponents of hard coal subsidization in Germany and other EU countries. Most importantly, in addition to the drain these subsidies impose on public budgets, substantial opportunity costs are implied, leading funds away from alternative, more beneficial public investments. From a social welfare perspective, we, therefore, recommend the rapid abolition of these subsidies not only in Germany, where in real terms the accumulated amount of subsidies has now far exceeded Euro 165 billion, but also all across Europe

  4. Nanostructural Evolution of Hard Turning Layers in Carburized Steel

    Science.gov (United States)

    Bedekar, Vikram

    The mechanisms of failure for components subjected to contact fatigue are sensitive to the structure and properties of the material surface. Although, the bulk material properties are determined by the steel making, forming and the heat treatment; the near surface material properties are altered during final material removal processes such as hard turning or grinding. Therefore, the ability to optimize, modulate and predict the near surface properties during final metal removal operations would be extremely useful in the enhancement of service life of a component. Hard machining is known to induce severely deformed layers causing dramatic microstructural transformations. These transformations occur via grain refinement or thermal phenomena depending upon cutting conditions. The aim of this work is to engineer the near surface nanoscale structure and properties during hard turning by altering strain, strain rate, temperature and incoming microstructure. The near surface material transformations due to hard turning were studied on carburized SAE 8620 bearing steel. Variations in parent material microstructures were introduced by altering the retained austenite content. The strain, strain rate and temperature achieved during final metal cutting were altered by varying insert geometry, insert wear and cutting speed. The subsurface evolution was quantified by a series of advanced characterization techniques such as transmission electron microscopy (TEM), glancing angle X-ray diffraction (GAXRD), X-ray stress evaluation and nanoindentation which were coupled with numerical modeling. Results showed that the grain size of the nanocrystalline near surface microstructure can be effectively controlled by altering the insert geometry, insert wear, cutting speed and the incoming microstructure. It was also evident that the near surface retained austenite decreased at lower cutting speed indicating transformation due to plastic deformation, while it increased at higher cutting

  5. Life cycle inventory analysis of hard coal based electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Sokka, L.; Koskela, S.; Seppaelae, J.

    2005-07-01

    In this document, the Life Cycle Inventory (LCI) of hard coal electricity is described. The LCI presents the product system of hard coal electricity covering all the life cycle stages from the extraction of resources to the delivery of electric power to the grid. The Finnish Meri-Pori power plant, which represents best available power plant technology, was used as a case study power plant. Inventory data on coal mining was collected using the average interventions of underground coal mining in Poland. Main emissions to air from the system mostly originate from conversing hard coal to electricity at the power plant. Electricity generation is the main source for CO{sub 2}, NO{sub x}, SO{sub 2} and most heavy metal emissions to air. The waste recycling rate of the investigated system is very high; almost 100% of the wastes produced at the power plant and over 85% of those produced during mining are recycled. In addition, approximately 20% of the methane released in the Polish mines is recovered and used as a fuel. LCI results were used in the life cycle impact assessment (LCIA) of hard coal electricity, and to identify the differences between the environmental impacts caused by oil shale electricity and coal electricity through their whole life cycle stages in the EU Life- Environment project (OSELCA). Inventory data produced in this study is applicable to systems using modern power plant technology and Eastern European hard coal. Two main blocks of the investigated system - mining and power generation - can also be used separately in different LCA studies. (orig.)

  6. The influence of material hardness on liquid droplet impingement erosion

    International Nuclear Information System (INIS)

    Highlights: • Liquid droplet impingement erosion is studied for various metal materials. • Average power dependency on droplet velocity is found as 7. • Power dependency on Vickers hardness is found as −4.5. • An empirical formula is constructed for erosion rates of metal materials. • Predicted erosion rate is well correlated with experiment within a factor of 1.5. - Abstract: This paper describes the experimental study on the liquid droplet impingement erosion of metal materials to understand the influence of material hardness on the erosion rate. The experiment is carried out using a water spray jet apparatus with a condition of relatively thin liquid film thickness. The metal materials tested are pure aluminum, aluminum alloy, brass, mild steel, carbon steel and stainless steel. The liquid droplets considered are 30 ± 5 μm in volume average diameter of water, which is the same order of droplet diameter in the actual pipeline in nuclear/fossil power plants. In order to understand the influence of material hardness on the liquid droplet impingement erosion, the scanning electron microscope (SEM) observation on the eroded surface and the measurement of erosion rate are carried out in the terminal stage of erosion. The experimental results indicate that the erosion rates are expressed by the droplet velocity, volume flux, Vickers hardness and the liquid film thickness, which are fundamentals of the liquid droplet impingement erosion. The empirical formula shows that the power index for droplet velocity dependency is found to be 7 with a scattering from 5 to 9 depending on the materials, while the power index for Vickers hardness dependency is found as −4.5

  7. Effort and Displeasure in People Who Are Hard of Hearing.

    Science.gov (United States)

    Matthen, Mohan

    2016-01-01

    Listening effort helps explain why people who are hard of hearing are prone to fatigue and social withdrawal. However, a one-factor model that cites only effort due to hardness of hearing is insufficient as there are many who lead happy lives despite their disability. This article explores other contributory factors, in particular motivational arousal and pleasure. The theory of rational motivational arousal predicts that some people forego listening comprehension because they believe it to be impossible and hence worth no effort at all. This is problematic. Why should the listening task be rated this way, given the availability of aids that reduce its difficulty? Two additional factors narrow the explanatory gap. First, we separate the listening task from the benefit derived as a consequence. The latter is temporally more distant, and is discounted as a result. The second factor is displeasure attributed to the listening task, which increases listening cost. Many who are hard of hearing enjoy social interaction. In such cases, the actual activity of listening is a benefit, not a cost. These people also reap the benefits of listening, but do not have to balance these against the displeasure of the task. It is suggested that if motivational harmony can be induced by training in somebody who is hard of hearing, then the obstacle to motivational arousal would be removed. This suggests a modified goal for health care professionals. Do not just teach those who are hard of hearing how to use hearing assistance devices. Teach them how to do so with pleasure and enjoyment. PMID:27355767

  8. Hard Times as Bodie: the allegorical functionality in E.L. Doctorow’s Welcome to Hard Times (1960

    Directory of Open Access Journals (Sweden)

    P. van der Merwe

    2007-07-01

    Full Text Available “Welcome to Hard Times” (1960, E.L. Doctorow’s first novel, differs from the rest of his oeuvre because it is not set in a metropolitan context like New York. References to historical events that contain an apparent “mixture” of “factual” and fictional elements that are typical of Doctorow’s oeuvre are less prominent than in his other fiction, though definitely not absent. An analysis of the pioneer setting, the town Hard Times, reveals that other settings (including metropolitan ones like New York are not merely representations of specific contexts, but portrayals with allegorical elements. Criticism of Doctorow’s fiction does not sufficiently point out the rationale of Doctorow’s fiction in relation to his first novel: it is not just the basic level that contains the true topicality but also the underlying causal and thematic relationships. This article sets out to explore “Welcome to Hard Times” as a case in point. The objective of this article is therefore also to show that an analysis of this novel provides a valuable basis for understanding the allegorical character of his fiction. Angus Fletcher’s theoretical analysis, “Allegory: the theory of a symbolic mode” (1964, serves as a useful starting point for the analysis of the allegorical value of space and the town Hard Times as a microcosmic or symbolic society, as well as the “daemonic agents” in the town and the role of causality.

  9. Evaluation of Open-Source Hard Real Time Software Packages

    Science.gov (United States)

    Mattei, Nicholas S.

    2004-01-01

    Reliable software is, at times, hard to find. No piece of software can be guaranteed to work in every situation that may arise during its use here at Glenn Research Center or in space. The job of the Software Assurance (SA) group in the Risk Management Office is to rigorously test the software in an effort to ensure it matches the contract specifications. In some cases the SA team also researches new alternatives for selected software packages. This testing and research is an integral part of the department of Safety and Mission Assurance. Real Time operation in reference to a computer system is a particular style of handing the timing and manner with which inputs and outputs are handled. A real time system executes these commands and appropriate processing within a defined timing constraint. Within this definition there are two other classifications of real time systems: hard and soft. A soft real time system is one in which if the particular timing constraints are not rigidly met there will be no critical results. On the other hand, a hard real time system is one in which if the timing constraints are not met the results could be catastrophic. An example of a soft real time system is a DVD decoder. If the particular piece of data from the input is not decoded and displayed to the screen at exactly the correct moment nothing critical will become of it, the user may not even notice it. However, a hard real time system is needed to control the timing of fuel injections or steering on the Space Shuttle; a delay of even a fraction of a second could be catastrophic in such a complex system. The current real time system employed by most NASA projects is Wind River's VxWorks operating system. This is a proprietary operating system that can be configured to work with many of NASA s needs and it provides very accurate and reliable hard real time performance. The down side is that since it is a proprietary operating system it is also costly to implement. The prospect of

  10. Prediction of hardness in pieces of quenched and tempered steel

    International Nuclear Information System (INIS)

    This presentation describes the first stage of a work plan to obtain a simple software, for predicting properties at certain points of a quenched and tempered piece. In this first stage, this prediction is limited to cylindrical pieces made with steels whose chemical composition is within a certain range. The methodology basically consists of obtaining , from experimental data, a mathematical tool able to predict the hardness value, for Jominy test piece ends made with this type of steel. This meant beginning with the analysis of the usual forms of theoretical calculation of Jominy curves of quenched samples, which resulted in a proposal to modify the Just equation. Two different mathematical methods were then developed, that could predict hardness values in tempered Jominy test pieces. One, based on the determination of polynomic equations, that reproduces the loss of hardness at points along the test piece, base on the quenching value and as a function of the tempering temperature. The other one, which uses the lineal multidimensional interpolation method, because of its ease of application, has been selected as the mathematical tool to use in the software under development. At this stage of the work, the relationship between the points on the piece and those on the Jominy test pieces is carried out by the Lamont method and the representative variable of the temperature/time combination for the tempering process itself, is obtained with software based on the Hollomon and Jaffe expression. Data is needed to define: a) chemical composition and grain size of the steel used, b) diameter of the piece, c) 'HG' severity of the quenching medium d) temperature and time of the tempering. The work's second stage continued with the addition of hardness values measured in Jominy test pieces made with other steels. The chemical composition and grain size data of each steel introduced are converted by the software into one more variable, using the concept of ideal critical

  11. Improved Hardness of Approximation for Stackelberg Shortest-Path Pricing

    CERN Document Server

    Briest, Patrick

    2009-01-01

    We consider the Stackelberg shortest-path pricing problem, which is defined as follows. Given a graph G with fixed-cost and pricable edges and two distinct vertices s and t, we may assign prices to the pricable edges. Based on the predefined fixed costs and our prices, a customer purchases a cheapest s-t-path in G and we receive payment equal to the sum of prices of pricable edges belonging to the path. Our goal is to find prices maximizing the payment received from the customer. While Stackelberg shortest-path pricing was known to be APX-hard before, we provide the first explicit approximation threshold and prove hardness of approximation within 2-o(1).

  12. Monitoring LMC X-3 in the Hard State

    Science.gov (United States)

    Smith, David

    This TOO proposal is an extension of the monitoring proposal #188 of this AO and should be reviewed along with it. LMC X-3 is the only black-hole binary which is usually active in the high (soft) state but occasionally makes transitions to the low (hard) state. By monitoring it twice a week, we hope to understand whether it displays hysteresis in it state transitions like 1E 1740.7-2942, GRS 1758-258, and the x- ray novae, or whether changes in luminosity and spectral index always occur simultaneously, as in Cyg X-1. In proposal #188 we get adequate spectra in the soft state (measuring the thermal component only) with 1.5 ksec pointings. Here we propose deeper (6 ksec, 3 PCU) pointings during the rare hard state, triggered by the other proposal or (less reliably) by the ASM.

  13. Hysteresis of modulated microwave absorption in hard superconductors

    International Nuclear Information System (INIS)

    The paper discusses the experimental results of investigations into hysteresis effect of microwave (MW) absorption in the following hard superconductors: Nb(poly- and monocrystals with deformation different degree), V3Si, NbSe2, YBa2Cu3O7-x (poly- and monocrystals), La2-xSr2Cu4-y, Tl2Ba2Sa2Cu3Ox, (ET)2Cu(SCN)2 organic superconductor. Definitions of parameters introduced to describe this effect are given. It is shown that MW hysteresis of absorption may be explained on the ground of the effect of Abrikosov vortex redistribution within skin-layer of a hard superconductor at variation of magnetic field scanning direction. 36 refs., 7 figs

  14. Radon measurements and valuation in German hard coal underground mines

    International Nuclear Information System (INIS)

    Measurements of the radon concentrations by sampling in return air shafts of all hard coal mines in the area of the Chief Mines Inspectorate of the Land NW were carried out by means of a specially designed method of measurement. The dependence of radon concentrations on atmospheric pressure and fan pressure was evaluated on the basis of the measurement results available. Long-term measurements are carried out on the surface of a coal mine at return air shafts, using continuous measuring instruments. For continuous long-term measurements underground, an intrinsically-safe measuring device, which involves processing and storage of the measured values in a CMOS micro-computer, was developed. The radon concentrations which were found are low as compared with maximum levels based on dose/effect correlations put forward by the International Committee for Radiological Protection. Considering radon, the risk of the hard coal miner can therefore be regarded as negligible

  15. Dispersion relations and subtractions in hard exclusive processes

    International Nuclear Information System (INIS)

    We study analytical properties of the hard exclusive process amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss D-term. The relation of this constant to the fixed pole contribution found by Brodsky, Close, and Gunion and defined by parton distributions is studied and proved for momentum transfers exceeding the typical hadronic scale. The continuation to the real photon limit is considered, and the numerical correspondence between lattice simulations of the D-term and low energy Thomson amplitude is found. For sufficiently large t the subtraction may be expressed in a form similar to that suggested earlier for real Compton scattering

  16. Fuzzy and Regression Modelling of Hard Milling Process

    Directory of Open Access Journals (Sweden)

    A. Tamilarasan

    2014-04-01

    Full Text Available The present study highlights the application of box-behnken design coupled with fuzzy and regression modeling approach for making expert system in hard milling process to improve the process performance with systematic reduction of production cost. The important input fields of work piece hardness, nose radius, feed per tooth, radial depth of cut and axial depth cut were considered. The cutting forces, work surface temperature and sound pressure level were identified as key index of machining outputs. The results indicate that the fuzzy logic and regression modeling technique can be effectively used for the prediction of desired responses with less average error variation. Predicted results were verified by experiments and shown the good potential characteristics of the developed system for automated machining environment.

  17. Observing Galactic Black Hole Sources in Hard X-rays

    CERN Document Server

    Rao, A R

    2013-01-01

    Observations of Galactic black hole sources are traditionally done in the classical X-ray range (2 -- 10 keV) due to sensitivity constraints. Most of the accretion power, however, is radiated above 10 keV and the study of these sources in hard X-rays has the potential to unravel the radiation mechanisms operating at the inner region of the accretion disk, which is believed to be the seat of a myriad of fascinating features like jet emission, high frequency QPO emission etc. I will briefly summarise the long term hard X-ray observational features like spectral state identification, state transitions and hints of polarised emission, and describe the new insights that would be provided by the forthcoming Astrosat satellite, particularly emphasising the contributions expected from the CZT-Imager payload.

  18. Fiber Bragg grating strain sensor for hard rocks

    Science.gov (United States)

    Castro-Caicedo, Alvaro; Nieto-Callejas, María. J.; Torres, Pedro

    2015-09-01

    Strain is an important property to be measured in rock structures such as tunnels, slopes, dams, and mining. However, commercial surface mountable fiber Bragg grating (FBG) strain sensors are packaged in planar configuration, which is not appropriate for the irregular surface of the rocks since an unacceptable bonding layer fails to transfer the strain from the rock to the FBG. As a first approach to this problem, in this work we analyze packaged FBG sensors for cylindrical samples of hard rocks. A calibration process was carried out to evaluate the performance of the packaging and bonding layer as compared to electrical resistance strain gage methods. We show the importance of both packaging and bonding layer in FBG sensor technology for measuring strain in hard rocks.

  19. The Role Played by Computation in Understanding Hard Materials

    Directory of Open Access Journals (Sweden)

    John Edward Lowther

    2011-06-01

    Full Text Available In the last decade, computation has played a valuable role in the understanding of materials. Hard materials, in particular, are only part of the application. Although materials involving B, C, N or O remain the most valued atomic component of hard materials, with diamond retaining its distinct superiority as the hardest, other materials involving a wide variety of metals are proving important. In the present work the importance of both ab-initio approaches and molecular dynamics aspects will be discussed with application to quite different systems. On one hand, ab-initio methods are applied to lightweight systems and advanced nitrides. Following, the use of molecular dynamics will be considered with application to strong metals that are used for high temperature applications.

  20. Hard gap in epitaxial semiconductor-superconductor nanowires

    DEFF Research Database (Denmark)

    Chang, W.; Albrecht, S. M.; Jespersen, T. S.;

    2015-01-01

    Many present and future applications of superconductivity would benefit from electrostatic control of carrier density and tunneling rates, the hallmark of semiconductor devices. One particularly exciting application is the realization of topological superconductivity as a basis for quantum...... information processing. Proposals in this direction based on proximity effect in semiconductor nanowires are appealing because the key ingredients are currently in hand. However, previous instances of proximitized semiconductors show significant tunneling conductance below the superconducting gap, suggesting...... a continuum of subgap states---a situation that nullifies topological protection. Here, we report a hard superconducting gap induced by proximity effect in a semiconductor, using epitaxial Al-InAs superconductor-semiconductor nanowires. The hard gap, along with favorable material properties and gate...

  1. Backscatter, anisotropy, and polarization of solar hard X-rays

    Science.gov (United States)

    Bai, T.; Ramaty, R.

    1978-01-01

    The problems of anisotropy, polarization, center-to-limb variation of the X-ray spectrum, and Compton backscatter are investigated in a study of solar hard X-rays. Effect of backscatter are found particularly important for anisotropic sources which emit hard X-rays predominantly toward the photosphere; for such anisotropic primary X-ray sources, the observed X-ray flux near 30 keV does not depend significantly on the position of the flare. In addition, the degree of polarization of the sum of the primary and reflected X-rays with energies in the 15 to 30 keV range may be as high as 30%. Determination of the height and anisotropy of the primary X-ray sources from study of the albedo patch is also discussed.

  2. Submicron cubic boron nitride as hard as diamond

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guoduan; Kou, Zili, E-mail: kouzili@scu.edu.cn, E-mail: yanxz@hpstar.ac.cn; Lei, Li; Peng, Fang; Wang, Qiming; Wang, Kaixue; Wang, Pei; Li, Liang; Li, Yong; Wang, Yonghua [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Yan, Xiaozhi, E-mail: kouzili@scu.edu.cn, E-mail: yanxz@hpstar.ac.cn; Li, Wentao [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203 (China); Bi, Yan [Institute of Fluid Physics and National Key Laboratory of Shockwave and Detonation Physic, China Academy of Engineering Physics, Mianyang 621900 (China); Leng, Yang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong (China); He, Duanwei [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Institute of Fluid Physics and National Key Laboratory of Shockwave and Detonation Physic, China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-03-23

    Here, we report the sintering of aggregated submicron cubic boron nitride (sm-cBN) at a pressure of 8 GPa. The sintered cBN compacts exhibit hardness values comparable to that of single crystal diamond, fracture toughness about 5-fold that of cBN single crystal, in combination with a high oxidization temperature. Thus, another way has been demonstrated to improve the mechanical properties of cBN besides reducing the grain size to nano scale. In contrast to other ultrahard compacts with similar hardness, the sm-cBN aggregates are better placed for potential industrial application, as their relative low pressure manufacturing perhaps be easier and cheaper.

  3. Influence of Hard Tool Coatings on Process of Stamping

    DEFF Research Database (Denmark)

    Zajec, Bostjan; Podgornik, Bojan; Bay, Niels; Vizintin, Joze

    Blanking/punching is a process which enables mass production of very demanding products, such as lamellas for electrical engines, generators and similar devices. Tool wear in the blanking/punching process has large influence on the product surface quality as well as on tool life. Improvement of...... tool life can be achieved by proper selection of tool materials and possible coatings. In mass production the tools are usually made of WC, which however, results in expensive tools and long time of delivery. The aim of the present investigation was to determine the influence of different tool...... materials and possible hard coatings as alternative tool materials. For this purpose the blanking/punching process was first analyzed by a numerical model and based on the results four different tool materials and three hard coatings were included in the investigation and tested in a model test rig as well...

  4. Hard single diffractive jet production at D0

    Energy Technology Data Exchange (ETDEWEB)

    Abachi, S. [Fermi National Accelerator Lab., Batavia, IL (United States); Abbott, B. [New York Univ., NY (United States); Abolins, M. [Michigan State Univ., East Lansing, MI (United States)] [and others; D0 Collaboration

    1996-08-01

    Preliminary results from the D{null} experiment on jet production with forward rapidity gaps in {ital p{anti p}} collisions are presented. A class of dijet events with a forward rapidity gap is observed at center-of-mass energies {radical}s = 1800 GeV and 630 GeV. The number of events with rapidity gaps at both center-of-mass energies is significantly greater than the expectation from multiplicity fluctuations and is consistent with a hard single diffractive process. A small class of events with two forward gaps and central dijets is also observed at 1800 GeV. This topology is consistent with hard double pomeron exchange.

  5. Hard gap in epitaxial semiconductor-superconductor nanowires.

    Science.gov (United States)

    Chang, W; Albrecht, S M; Jespersen, T S; Kuemmeth, F; Krogstrup, P; Nygård, J; Marcus, C M

    2015-03-01

    Many present and future applications of superconductivity would benefit from electrostatic control of carrier density and tunnelling rates, the hallmark of semiconductor devices. One particularly exciting application is the realization of topological superconductivity as a basis for quantum information processing. Proposals in this direction based on the proximity effect in semiconductor nanowires are appealing because the key ingredients are currently in hand. However, previous instances of proximitized semiconductors show significant tunnelling conductance below the superconducting gap, suggesting a continuum of subgap states--a situation that nullifies topological protection. Here, we report a hard superconducting gap induced by the proximity effect in a semiconductor, using epitaxial InAs-Al semiconductor-superconductor nanowires. The hard gap, together with favourable material properties and gate-tunability, makes this new hybrid system attractive for a number of applications, as well as fundamental studies of mesoscopic superconductivity. PMID:25581886

  6. On the Convergence of Iterative Receiver Algorithms Utilizing Hard Decisions

    Directory of Open Access Journals (Sweden)

    Jürgen F. Rößler

    2009-01-01

    Full Text Available The convergence of receivers performing iterative hard decision interference cancellation (IHDIC is analyzed in a general framework for ASK, PSK, and QAM constellations. We first give an overview of IHDIC algorithms known from the literature applied to linear modulation and DS-CDMA-based transmission systems and show the relation to Hopfield neural network theory. It is proven analytically that IHDIC with serial update scheme always converges to a stable state in the estimated values in course of iterations and that IHDIC with parallel update scheme converges to cycles of length 2. Additionally, we visualize the convergence behavior with the aid of convergence charts. Doing so, we give insight into possible errors occurring in IHDIC which turn out to be caused by locked error situations. The derived results can directly be applied to those iterative soft decision interference cancellation (ISDIC receivers whose soft decision functions approach hard decision functions in course of the iterations.

  7. Linear viscoelasticity in dispersions of adhesive hard spheres

    Science.gov (United States)

    Woutersen, A. T. J. M.; Mellema, J.; Blom, C.; de Kruif, C. G.

    1994-07-01

    The viscoelastic behavior of concentrated dispersions of adhesive hard spheres was investigated. By changing the temperature, the interaction potential of the particles was varied from a hard sphere repulsion to a strong attraction. Using torsion resonators and a nickel tube resonator the complex viscosity was measured in the frequency range 70-250 000 Hz. The results were described on the basis of a simple mechanical model in terms of a series of relaxation times and a single relaxation strength. The temperature dependence of the longest relaxation time and the relaxation strength indicated that the system undergoes a kinetic transition with decreasing temperature. The transition could be identified with the percolation threshold. Above the transition temperature where the dispersion is in a stable, fluid state, linear viscoelastic behavior is observed. Below the percolation threshold but still in the one-phase region, nonlinear viscoelasticity was measured, even at the smallest strains.

  8. Hard-Core Repulsion and Supersolid Cluster Crystals

    Science.gov (United States)

    Boninsegni, Massimo

    2016-09-01

    We study the effect of a short-ranged hard-core repulsion on the stability and superfluid properties of the cluster crystal phase of two-dimensional (2D) soft-core bosons. Results of Quantum Monte Carlo simulations on a cogent test case suggest that the main physical properties of the phase remain unaltered if the range d of the inner repulsive core is sufficiently short, even if the strength of the repulsion is several orders of magnitude greater than the outer soft-core barrier. Only if d is an appreciable fraction of the size of the clusters ([InlineEquation not available: see fulltext.] 5 %) does a sufficiently strong hard-core repulsion cause the crystal to break down into a homogeneous superfluid; a moderate inner core repulsion enhances the superfluid response of the crystalline phase.

  9. Structural qualia: a solution to the hard problem of consciousness

    Directory of Open Access Journals (Sweden)

    Kristjan eLoorits

    2014-03-01

    Full Text Available The hard problem of consciousness has been often claimed to be unsolvable by the methods of traditional empirical sciences. It has been argued that all the objects of empirical sciences can be fully analyzed in structural terms but that consciousness is (or has something over and above its structure. However, modern neuroscience has introduced a theoretical framework in which also the apparently non-structural aspects of consciousness, namely the so called qualia or qualitative properties, can be analyzed in structural terms. That framework allows us to see qualia as something compositional with internal structures that fully determine their qualitative nature. Moreover, those internal structures can be identified which certain neural patterns. Thus consciousness as a whole can be seen as a complex neural pattern that misperceives some of its own highly complex structural properties as monadic and qualitative. Such neural pattern is analyzable in fully structural terms and thereby the hard problem is solved.

  10. Hard-Core Repulsion and Supersolid Cluster Crystals

    Science.gov (United States)

    Boninsegni, Massimo

    2016-06-01

    We study the effect of a short-ranged hard-core repulsion on the stability and superfluid properties of the cluster crystal phase of two-dimensional (2D) soft-core bosons. Results of Quantum Monte Carlo simulations on a cogent test case suggest that the main physical properties of the phase remain unaltered if the range d of the inner repulsive core is sufficiently short, even if the strength of the repulsion is several orders of magnitude greater than the outer soft-core barrier. Only if d is an appreciable fraction of the size of the clusters ([InlineEquation not available: see fulltext.] 5 %) does a sufficiently strong hard-core repulsion cause the crystal to break down into a homogeneous superfluid; a moderate inner core repulsion enhances the superfluid response of the crystalline phase.

  11. A study of sound balances for the hard of hearing

    Science.gov (United States)

    Mathers, C. D.

    Over a period of years, complaints have been received from television viewers, especially those who are hard of hearing, that background sound (e.g., audience laughter, crowd noise, mood music) is often transmitted at too high a level with respect to speech, so that information essential to the understanding of the program is lost. To consider possible solutions to the problem, a working party was set up representing both broadcasters and organizations for the hard of hearing. At early meetings, it was resolved that a series of subjective tests should be carried out to determine what reduction of background levels would be needed to provide a significant improvement in the intelligibility of television speech for viewers with hearing difficulties. The preparation of test tapes and the analysis of results are given.

  12. Prediction problem in quantum mechanics is intractable (NP-hard)

    International Nuclear Information System (INIS)

    The authors prove that both the prediction problem and the problem of reconstructing the state from given observations in quantum mechanics are in the general case intractable (or, using the precise mathematical notion from complexity theory, NP-hard). This result can be of interest to two groups of readers: those who are well acquainted with the mathematical problems of quantum physics and those who are well acquainted with algorithmic complexity and NP. They do our best to make this text understandable to both. Therefore they include brief explanations of both the quantum mechanics formalism and the formal notion of intractable (NP-hard) problems. Those readers already familiar with one of these notions can simply skip the corresponding part

  13. Rock mechanics for hard rock nuclear waste repositories

    International Nuclear Information System (INIS)

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

  14. RD50 Collaboration overview: Development of new radiation hard detectors

    Science.gov (United States)

    Kuehn, S.

    2016-07-01

    Silicon sensors are widely used as tracking detectors in high energy physics experiments. This results in several specific requirements like radiation hardness and granularity. Therefore research for highly performing silicon detectors is required. The RD50 Collaboration is a CERN R&D collaboration dedicated to the development of radiation hard silicon devices for application in high luminosity collider experiments. Extensive research is ongoing in different fields since 2001. The collaboration investigates both defect and material characterization, detector characterization, the development of new structures and full detector systems. The report gives selected results of the collaboration and places an emphasis on the development of new structures, namely 3D devices, CMOS sensors in HV technology and low gain avalanche detectors.

  15. Photodetachment of H- near a Hard Spherical Surface

    Institute of Scientific and Technical Information of China (English)

    M. Haneef; Iftikhar Ahmad; A. Afaq; A. Rahman

    2012-01-01

    The photodetachment of a hydrogen negative ion (H- ) near a hard spherical surface is investigated by using the theoretical imaging method. The surface is oriented in such a fashion that the laser polarization direction is perpendicular to the principal axis of the spherical surface. Analytical expressions are derived for the detached-electron flux and photodetachment cross section. Strong interference patterns are observed in the detached-electron flux, while no visible oscillations are found in the photodetachment cross section.%The photodetachment of a hydrogen negative ion (H-) near a hard spherical surface is investigated by using the theoretical imaging method.The surface is oriented in such a fashion that the laser polarization direction is perpendicular to the principal axis of the spherical surface.Analytical expressions are derived for the detachedelectron flux and photodetachment cross section.Strong interference patterns are observed in the detachedelectron flux,while no visible oscillations are found in the photodetachment cross section.

  16. Temporality in“A Good Man is Hard to Find”

    Institute of Scientific and Technical Information of China (English)

    LIU Shuai-yi

    2014-01-01

    As a carefully designed work, Flannert O’Connor’s short story“A Good Man is Hard to Find”is a brilliant example for skillfully using narrative techniques to convey her Catholic faith. Mieke Bal’s theories of time in narratology provide a fresh perspective to explores the characterizations in Flannert O’Connor’s“A Good Man is Hard to Find”. Time functions greatly to the characterizations of the characters through the narrative text in terms of the story and the fabula. It helps to present the charac⁃ters’personalities by playing with the sequential ordering, rhythm and frequency. By using these narrative techniques, grand⁃mother’s selfishness, her moral inanition and her considerations that she is morally superior to others is fully expressed to the read⁃er as well as Misfit’s struggling and renascence to his disbeliefs of God and so on.

  17. Review of hard copy systems for digital medical imaging

    Science.gov (United States)

    Apple, Bernard A.; Tennant, Mark H.; Thomas, Jule W., Jr.

    1996-03-01

    In this paper we review image requirements and the potential use of various printing technologies to record digital diagnostic radiographic information. An analysis of limitations and advantages of alternate imaging systems compared to current laser imager/silver halide film systems will be presented. The future move to digital radiology along with its hard copy requirements will also be discussed. The winning technologies in the market place will be determined by their ability to provide adequate image quality at low cost while meeting productivity, durability, and convenience requirements. The first technology to meet these requirements will have a tremendous advantage in the market place. Medical imaging hard copy is dominated by the use of silver halide media providing monochrome images of diagnostic image quality. As new digital medical imaging modalities have emerged they have opened the door to new hard copy technologies. These new technologies have been born and nurtured outside the medical market by small markets with high image quality requirements or by large markets with lower image quality requirements. The former have tended to provide high cost, high quality solutions and the latter low cost, low quality solutions. Silver halide media still dominates, at least in part, because it provides high image quality at a relatively low cost. Yet, the trend away from wet silver halide is evident. These new hard copy technologies are being tested to determine their applicability to the medical market and are finding niches where they provide value. A clear winner that provides the required image quality at low cost has yet to emerge.

  18. Quantification of Minor Texture Components by Hard X-Rays

    OpenAIRE

    Poulsen, H. F.; Jensen, D. Juul; Tschentscher, T.; Wcislak, L.; Lauridsen, E.M.; Margulies, L; Schmidt, S.

    2001-01-01

    Non-destructive methods to determine the volume fraction of minor texture components with very low reflection intensities are presented. The methods are based on polycrystalline diffraction of hard X-rays from synchrotron sources. By focusing the X-rays and scanning the specimen, it is shown that volume fractions as low as 10-9 can be registered, provided that the crystallographic orientations of such volume elements are far away from any major texture component. Simultaneously, the spatial r...

  19. Monte Carlo computer simulation of sedimentation of charged hard spherocylinders

    International Nuclear Information System (INIS)

    In this article we present a NVT Monte Carlo computer simulation study of sedimentation of an electroneutral mixture of oppositely charged hard spherocylinders (CHSC) with aspect ratio L/σ = 5, where L and σ are the length and diameter of the cylinder and hemispherical caps, respectively, for each particle. This system is an extension of the restricted primitive model for spherical particles, where L/σ = 0, and it is assumed that the ions are immersed in an structureless solvent, i.e., a continuum with dielectric constant D. The system consisted of N = 2000 particles and the Wolf method was implemented to handle the coulombic interactions of the inhomogeneous system. Results are presented for different values of the strength ratio between the gravitational and electrostatic interactions, Γ = (mgσ)/(e2/Dσ), where m is the mass per particle, e is the electron's charge and g is the gravitational acceleration value. A semi-infinite simulation cell was used with dimensions Lx ≈ Ly and Lz = 5Lx, where Lx, Ly, and Lz are the box dimensions in Cartesian coordinates, and the gravitational force acts along the z-direction. Sedimentation effects were studied by looking at every layer formed by the CHSC along the gravitational field. By increasing Γ, particles tend to get more packed at each layer and to arrange in local domains with an orientational ordering along two perpendicular axis, a feature not observed in the uncharged system with the same hard-body geometry. This type of arrangement, known as tetratic phase, has been observed in two-dimensional systems of hard-rectangles and rounded hard-squares. In this way, the coupling of gravitational and electric interactions in the CHSC system induces the arrangement of particles in layers, with the formation of quasi-two dimensional tetratic phases near the surface

  20. Liquid money or hard cash? Drowning into granular material

    OpenAIRE

    Bagnoli, Franco

    2016-01-01

    In British English, the term "hard cash" refers to the form of payment using coins or bill, rather than cheques or credit or money transfer. In American English, it is often prefixed by the adjective "cold". On the contrary, in Italian the equivalent expression "denaro liquido" can be literary translated as "liquid money". In French the expression is equivalent with the additional factor, with respect to the rest of this discussion, that money becomes "argent". We have therefore two very diff...

  1. Structure and distribution of arches in shaken hard sphere deposits

    OpenAIRE

    Pugnaloni, Luis A.; Barker, G. C.

    2003-01-01

    We investigate the structure and distribution of arches formed by spherical, hard particles shaken in an external field after they come to rest. Arches (or bridges) are formed during a computer-simulated, non-sequential deposition of the spheres after each shaking cycle. We identify these arches by means of a connectivity criterion and study their structural characteristics and spatial distribution. We find that neither the size distribution nor the shape of the arches is strongly affected by...

  2. Flow anisotropies due to momentum deposition from hard partons

    CERN Document Server

    Tomasik, Boris

    2015-01-01

    In nuclear collisions at the LHC large number of hard partons are created in initial partonic interactions, so that it is reasonable to suppose that they do not thermalise immediately but deposit their energy and momentum later into the evolving hot quark-gluon fluid. We show that this mechanism leads to contribution to flow anisotropies at all orders which are non-negligible and should be taken into account in realistic simulations.

  3. Orientational order of the two-dimensional hard disk system

    OpenAIRE

    Jaster, Andreas

    1998-01-01

    We report Monte Carlo results for the two-dimensional hard disk system. Simulations were performed in the NVT ensemble with up to 65536 disks, using a new updating scheme. We analyze the bond orientational order parameter and correlation length in the isotropic phase and the scaling behaviour of the bond orientational order parameter in the transition region. The data are consistent with predictions of the Kosterlitz-Thouless-Halperin-Nelson-Young theory, while a first-order phase transition ...

  4. TRIBOLOGICAL PROPERTIES AND WEAR MECHANISM OF HARD COATINGS

    OpenAIRE

    Ugues, Daniele; Maizza, Giovanni

    2013-01-01

    In the modern technology, tribologically suitable components and devices are important to increase the energy efficiency. It is possible when one can reduce the friction coefficient and wear of sliding components. The economic effectiveness can be achieved by better tribological system and therefore research in tribology is aimed at minimizing the energy losses resulting from friction and wear. In this view, hard coatings deposited by physical vapor deposition (PVD) are adequate solutions for...

  5. Hard breakup of two nucleons from the 3He nucleus

    International Nuclear Information System (INIS)

    We investigate a large angle photodisintegration of two nucleons from the 3He nucleus within the framework of the hard rescattering model (HRM). In the HRM a quark of one nucleon knocked out by an incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with large relative momentum. Assuming the dominance of the quark-interchange mechanism in a hard nucleon-nucleon scattering, the HRM allows the expression of the amplitude of a two-nucleon breakup reaction through the convolution of photon-quark scattering, NN hard scattering amplitude, and nuclear spectral function, which can be calculated using a nonrelativistic 3He wave function. The photon-quark scattering amplitude can be explicitly calculated in the high energy regime, whereas for NN scattering one uses the fit of the available experimental data. The HRM predicts several specific features for the hard breakup reaction. First, the cross section will approximately scale as s-11. Second, the s11 weighted cross section will have the shape of energy dependence similar to that of s10 weighted NN elastic scattering cross section. Also one predicts an enhancement of the pp breakup relative to the pn breakup cross section as compared to the results from low energy kinematics. Another result is the prediction of different spectator momentum dependencies of pp and pn breakup cross sections. This is due to the fact that the same-helicity pp-component is strongly suppressed in the ground state wave function of 3He. Because of this suppression the HRM predicts significantly different asymmetries for the cross section of polarization transfer NN breakup reactions for circularly polarized photons. For the pp breakup this asymmetry is predicted to be zero while for the pn it is close to (2/3).

  6. The hard start phenomena in hypergolic engines. Volume 1: Bibliography

    Science.gov (United States)

    Miron, Y.; Perlee, H. E.

    1974-01-01

    A bibliography of reports pertaining to the hard start phenomenon in attitude control rocket engines on Apollo spacecraft is presented. Some of the subjects discussed are; (1) combustion of hydrazine, (2) one dimensional theory of liquid fuel rocket combustion, (3) preignition phenomena in small pulsed rocket engines, (4) experimental and theoretical investigation of the fluid dynamics of rocket combustion, and (5) nonequilibrium combustion and nozzle flow in propellant performance.

  7. Radiation Hard Fiber Optic Gyro Inertial Reference Unit

    OpenAIRE

    Sexton, Gregory

    1997-01-01

    Orbital Science Corporation and Fibersense Technology Corporation are working together to produce a radiation hard, interferometric fiber optic gyro inertial reference unit. The advantages of fiber optic gyros over both ring laser gyros and traditional mechanical gyros have been well documented. Fiber optic gyros offer a rugged, low cost alternative to other gyro technologies. Their straight forward design provides for a gyro that is highly reliable with a low parts count and simple construct...

  8. Optimization by Quantum Annealing: Lessons from hard 3-SAT cases

    OpenAIRE

    Battaglia, Demian; Santoro, Giuseppe; Tosatti, Erio

    2005-01-01

    The Path Integral Monte Carlo simulated Quantum Annealing algorithm is applied to the optimization of a large hard instance of the Random 3-SAT Problem (N=10000). The dynamical behavior of the quantum and the classical annealing are compared, showing important qualitative differences in the way of exploring the complex energy landscape of the combinatorial optimization problem. At variance with the results obtained for the Ising spin glass and for the Traveling Salesman Problem, in the presen...

  9. Hard Instances of the Constrained Discrete Logarithm Problem

    OpenAIRE

    Mironov, Ilya; Mityagin, Anton; Nissim, Kobbi

    2006-01-01

    The discrete logarithm problem (DLP) generalizes to the constrained DLP, where the secret exponent $x$ belongs to a set known to the attacker. The complexity of generic algorithms for solving the constrained DLP depends on the choice of the set. Motivated by cryptographic applications, we study sets with succinct representation for which the constrained DLP is hard. We draw on earlier results due to Erd\\"os et al. and Schnorr, develop geometric tools such as generalized Menelaus' theorem for ...

  10. Non-Hodgkin′s lymphoma of the hard palate

    OpenAIRE

    Jayakrishnan R; Thomas Gigi; Kumar Aswin; Nair Rekha

    2008-01-01

    Background: Non-Hodgkin′s lymphoma usually involves lymph nodes but can also involve extranodal sites. Oral lymphomas are relatively rare and often difficult to diagnose in a clinical setting. We present a case of a patient of non-Hodgkin′s lymphoma of the hard palate who had undergone external beam radiation therapy and was found to be well 1 year following treatment. Case presentation: A 43-year-old male attended the Community Oncology Division of Regional Cancer Centre wit...

  11. Micromagnetic simulations with periodic boundary conditions: Hard-soft nanocomposites

    OpenAIRE

    Wysocki, Aleksander L.; Antropov, Vladimir P.

    2015-01-01

    We developed a micromagnetic method for modeling magnetic systems with periodic boundary conditions along an arbitrary number of dimensions. The main feature is an adaptation of the Ewald summation technique for evaluation of long-range dipolar interactions. The method was applied to investigate the hysteresis process in hard-soft magnetic nanocomposites with various geometries. The dependence of the results on different micromagnetic parameters was studied. We found that for layered structur...

  12. Complex Oscillatory Yielding of Model Hard-Sphere Glasses

    OpenAIRE

    Koumakis, N.; Brady, J. F.; Petekidis, G.

    2013-01-01

    The yielding behaviour of hard sphere glasses under large amplitude oscillatory shear has been studied by probing the interplay of Brownian motion and shear-induced diffusion at varying oscillation frequencies. Stress, structure and dynamics are followed by experimental rheology and Browian Dynamics simulations. Brownian motion assisted cage escape dominates at low frequencies while escape through shear-induced collisions at high ones, both related with a yielding peak in\\ $G^{\\prime \\prime}$...

  13. A Hard Real-Time Kernel for Motorola Microcontrollers

    OpenAIRE

    Mumolo, Enzo; Nolich, Massimiliano; Oss Noser, Massimo

    2001-01-01

    This paper describes a real-time kernel for running embedded applications on a recent family of Motorola microcontrollers. Both periodic and aperiodic real-time tasks are managed, as well as non real-time tasks. The kernel has been called Yartos, and uses a hard real-time scheduling algorithm based on an EDF approach for the periodic task; aperiodic tasks are executed with a Total Bandwith Server.

  14. Hardness and elastic modulus of silicalite-1 crystal twins

    Czech Academy of Sciences Publication Activity Database

    Brabec, Libor; Boháč, Petr; Stranyánek, Martin; Čtvrtlík, Radim; Kočiřík, Milan

    2006-01-01

    Roč. 94, 1-3 (2006), s. 226-233. ISSN 1387-1811 R&D Projects: GA AV ČR 1QS100100563; GA ČR GA203/05/0846 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100522 Keywords : silicalite-1 crystlas * hardness * elastic modulus * HF+etching patterns Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.796, year: 2006

  15. Random close packing fractions of lognormal distributions of hard spheres

    OpenAIRE

    Farr, Robert S.

    2013-01-01

    We apply a recent one-dimensional algorithm for predicting random close packing fractions of polydisperse hard spheres [Farr and Groot, J. Chem. Phys. 133, 244104 (2009)] to the case of lognormal distributions of sphere sizes and mixtures of such populations. We show that the results compare well to two much slower algorithms for directly simulating spheres in three dimensions, and show that the algorithm is fast enough to tackle inverse problems in particle packing: designing size distributi...

  16. Quark Number Susceptibility in Hard Thermal Loop Approximation

    OpenAIRE

    Chakraborty, Purnendu; Mustafa, Munshi G.; Thoma, Markus H.

    2001-01-01

    We calculate the quark number susceptibility in the deconfined phase of QCD using the hard thermal loop (HTL) approximation for the quark propagator. This improved perturbation theory takes into account important medium effects such as thermal quark masses and Landau damping in the quark-gluon plasma. We explicitly show that the Landau damping part in the quark propagator for spacelike quark momenta does not contribute to the quark number susceptibility due to the quark number conservation. W...

  17. Density profiles of ionic liquids at a hard wall

    OpenAIRE

    Schramm, Sebastian M.

    2008-01-01

    In this work a high energy x-ray reflectivity study of deeply buried interfaces between room temperature ionic liquids (RTILs) and a sapphire hard wall is reported. For the first time the interfacial structure was obtained with molecular resolution. The experiments have been carried out at beamline ID15A (ESRF, Grenoble) using the HEMD (High Energy Micro Diffraction) instrument. The thorough analysis of the experimental reflectivities gives clear evidence of a pronounced molecular layering at...

  18. Computational topology for configuration spaces of hard disks

    CERN Document Server

    Carlsson, Gunnar; Kahle, Matthew; Mason, Jeremy

    2011-01-01

    We explore the topology of configuration spaces of hard disks experimentally, and show that several changes in the topology can already be observed with a small number of particles. The results illustrate a theorem of Baryshnikov, Bubenik, and Kahle that critical points correspond to configurations of disks with balanced mechanical stresses, and suggest conjectures about the asymptotic topology as the number of disks tends to infinity.

  19. Computational topology for configuration spaces of hard disks.

    Science.gov (United States)

    Carlsson, Gunnar; Gorham, Jackson; Kahle, Matthew; Mason, Jeremy

    2012-01-01

    We explore the topology of configuration spaces of hard disks experimentally and show that several changes in the topology can already be observed with a small number of particles. The results illustrate a theorem of Baryshnikov, Bubenik, and Kahle that critical points correspond to configurations of disks with balanced mechanical stresses and suggest conjectures about the asymptotic topology as the number of disks tends to infinity. PMID:22400561

  20. Hard-core deuterium fibre Z-pinch

    International Nuclear Information System (INIS)

    A novel fusion concept is considered, related to present day deuterium fibre pinch experiments. The hard core is allowed to persist during the discharge, being completely ablated only at the end of the pulse. The Lawson requirement ητΕ> 1022M-3s for the catalysed D-D reaction is exceeded at a plasma temperature >30 keV by using high power generators with short pulse times of order a few ns. (au)