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. EFFECT OF VARIOUS FIRE RETARDANTS ON BRINELL HARDNESS OF SOME WOOD

    Directory of Open Access Journals (Sweden)

    Şeref Kurt

    2009-08-01

    Full Text Available This study was performed to determine the impact of impregnation materials on the Brinell hardness of varnished wood materials. For this purpose, test specimens prepared from Scotch pine (Pinus sylvestris L. and Oriental beech (Fagus orientalis Lipsky, which met the requirements of ASTM D 358, were impregnated according to ASTM D 1413-07 with borax, boric acid, zinc chloride, and di-ammonium phosphate by a vacuum technique. After impregnation, the surfaces were coated by cellulosic, synthetic, and polyurethane varnishes in accordance with ASTM D 3023. The Brinell hardness of the specimens after the varnishing process was determined in accordance with ASTM D 4366. According to the result of the tests, the highest Brinell hardness (135.40 kpm/m² was determined in oriental beech samples, cut tangentially, impregnated with di- ammonium phosphate, and varnished with polyurethane. The lowest Brinell hardness (23.20 kpm/m² was determined in Scotch pine control samples, cut radially and synthetically varnished.

  3. Application of hardness testing in foundry processing operations: A university and industry partnership

    Science.gov (United States)

    Martin, Donald H.; Lash, Bruce

    1993-01-01

    The objectives are the following: (1) to plan a tour of local manufacturing facility to observe hardness testing methods used and how they support the manufacturing process today; (2) to learn the operation of Brinell Hardness Testing and equipment set up with samples of accessory equipment for testing of various materials; (3) to use a Brinell scope (hand magnifier) to measure the diameter of the test indentation (in millimeters); (4) to use the hardness equation to determine the spherical area of the indentation and the calculation of the Brinell Hardness Number; (5) to use standard charts for ASTM standard size indenters to find the hardness number; and (6) to learn a method of conversion of the Brinell number to other hardness scales, their common usage, and also to convert the hardness number to the approximate tensile strength.

  4. Estimation of cyclic stress-strain curves for low-alloy steel from hardness

    Directory of Open Access Journals (Sweden)

    R. Basan

    2010-04-01

    Full Text Available This article describes investigations into the existence of correlation between experimentally determined cyclic parameters and hardness of quenched and tempered representative low-alloy steel 42CrMo4. A good correlation was found to exist between cyclic strength coefficient K’ and Brinell hardness HB, but not between cyclic strain hardening exponent n‘ and hardness HB. Nevertheless, good agreement between calculated and experimental cyclic stress-strain curves shows that cyclic parameters i.e. cyclic stress-strain curves of the investigated steel can be successfully estimated from its hardness.

  5. 小负荷布氏硬度基准装置系统%Development of the Primary Standard of Low Load Brinell Hardness Machine

    Institute of Scientific and Technical Information of China (English)

    刘吉萍

    2008-01-01

    在静重式硬度基准中实现试验力的自动控制;采用光栅测量技术使压痕测量达到了最高精度等级;给出压痕测量中目视瞄准误差计算方法.根据计量基准的特殊性,从技术方案、具体结构等方面上,确保小负荷硬度基准装置具有计量性能稳定和能长期正常运行的特点.

  6. 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.

  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. Influence exothermical mixtures contents Na or B on elongation and hardness AlSi12 alloy

    Directory of Open Access Journals (Sweden)

    T. Lipiński

    2008-04-01

    Full Text Available The experiments were conducted on alloy AlSi12, following a factor design 23 for 3 independent variables. Mixtures composed of NaNO3, Na2B4O7, and Mg were used for alloy treatment. The amount of a reducing agent (Mg necessary to carry out the process was calculated on the basis of chemical reactions. The mass fraction (weight in weight concentration of individual variables is presented in Table 1. Results of study present by graphical forms. Figures 2-8 present until elongation (A5 and Brinell hardness (HB for each variable, at extreme (lower or higher levels of the other two.

  9. Standard test method for rapid indentation hardness testing of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1984-01-01

    1.1 This test method covers the procedure for rapid indentation hardness testing of metallic materials as an alternative to Test Method E 10 on standard Brinell hardness. It includes methods for the verification of rapid indentation hardness testing machines, Part B, and the calibration of reference hardness test blocks, Part C. 1.2 The values stated in SI units are to be regarded as standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  10. 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.

  11. Comparison of linear dimensional change, surface hardness and surface roughness of refractory model prepared from two different duplicating media.

    Science.gov (United States)

    Porwal, Amit; Chandrashekhar, Naveen H; Nadiger, Ramesh K; Meshramkar, Roseline D; Guttal, Satyabodh S

    2011-03-01

    The aim of this study was to evaluate and compare the linear dimensional change, surface hardness and surface roughness of the refractory casts poured against different duplicating media. Polyvinyl siloxane and Agar-agar were used for duplicating the stainless steel die. Sixty refractory models were prepared which were divided into two groups: I and II with 30 samples each respectively. Each group was subdivided into 3 subgroups with 10 samples each which were treated differently. All the specimens were measured for the linear dimensional change and surface hardness and the obtained data was statistically analyzed. Surface roughness was evaluated qualitatively taking SEM photomicrographs. Statistical analysis of linear dimensional change using one-way ANOVA showed statistically significant difference between subgroups of group I and non-significant difference between subgroups of group II. One-way ANOVA for Brinell hardness number showed statistically significant difference between the subgroups of group I & II. Student's 't' test results for linear dimensional change among different subgroups of group I & II showed significant difference between IA-IIA, IB-IIB, IC-IIC. Similarly 't'-test results for Brinell hardness number showed significant difference between subgroups IA-IIA, IB-IIB, and IC-IIC. Surface characteristics of the refractory casts poured against polyvinyl siloxane duplicating media were found to be better than the Agar media.

  12. 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.

  13. Effect of chemical composition on microstructure, hardness and electrical conductivity profiles of the Bi-Cu-Ga alloys at 100 °C

    Directory of Open Access Journals (Sweden)

    Dejan Gurešić

    2016-09-01

    Full Text Available Theoretical calculation and experimental investigation of the isothermal section of a ternary Bi-Cu-Ga system at 100 oC are presented in this paper. Thermodynamic binary-based calculation of the isothermal section was performed using Pandat software. Experimental investigation included microstructural analysis carried out using light optical microscopy (LOM and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS, phase composition analysis using X-ray diffraction (XRD, Brinell and Vickers hardness testing and electrical conductivity measurements. In total, thirty alloy samples with compositions along three vertical sections Bi-CuGa, Cu-BiGa and Ga-BiCu were studied. The obtained experimental results support the calculated phase regions of the isothermal section at 100 oC. Hardness of individual phases as well as hardness and electrical conductivity of the studied alloys were measured. Based on the experimentally obtained results iso-lines of Brinell hardness and electrical conductivity along the whole compositional range were calculated by using appropriate mathematical models.

  14. Experimental investigation of hardness of FSW and TIG joints of Aluminium alloys of AA7075 and AA6061

    Directory of Open Access Journals (Sweden)

    Chetan Patil

    2016-07-01

    Full Text Available This paper reports hardness testing conducted on welded butt joints by FSW and TIG welding process on similar and dissimilar aluminium alloys. FSW joints were produced for similar alloys of AA7075T651 and dissimilar alloys of AA7075T651- AA6061T6. The Friction stir welds of AA7075 & AA6061 aluminium alloy were produced at different tool rotational speeds of 650,700, 800, 900, 1000 and transverse speed of 30, 35, 40 mm/min. TIG welding was conducted along the rolling direction of similar and dissimilar aluminium plates. The Brinell hardness testing techniques were employed to conduct the tests; these tests were conducted on the welds to ascertain the joint integrity before characterization to have an idea of the quality of the welds

  15. 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.

  16. 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.

  17. Hardness Enhancement of Amalgam Teeth Fillings Using Diode Laser (675 nm

    Directory of Open Access Journals (Sweden)

    Nafie Almuslet

    2011-10-01

    Full Text Available This work aimed to enhance the hardness of human teeth filler material (Amalgam, in a short possible time via irradiation by low level laser. Hardening tests were carried out on different amalgam mixtures subjected to irradiation for two minutes by diode laser with wavelength of 675 nm and power of 15 mW. The samples were left for different time intervals and for each time interval hardening test was carried out using Brinell hardness test. Other samples were prepared for the same test with the same procedure but without irradiation, i.e. control group. The irradiated samples showed a considerable increasing in their hardness compared with samples without irradiation. The samples irradiated by laser need only 6 hours to reach the same value of hardness that the control group reached after 30 hours. In Conclusion, the irradiation of amalgam by this type of laser with the above parameters believed to be recrystalizing the material so it become harder with shorter time compared with the amalgam without irradiation.

  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. Wear of hard materials by hard particles

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.

    2003-10-01

    Hard materials, such as WC-Co, boron carbide, titanium diboride and composite carbide made up of Mo2C and WC, have been tested in abrasion and erosion conditions. These hard materials showed negligible wear in abrasion against SiC particles and erosion using Al2O3 particles. The WC-Co materials have the highest wear rate of these hard materials and a very different material removal mechanism. Wear mechanisms for these materials were different for each material with the overall wear rate controlled by binder composition and content and material grain size.

  20. Hardness Tester for Polyur

    Science.gov (United States)

    Hauser, D. L.; Buras, D. F.; Corbin, J. M.

    1987-01-01

    Rubber-hardness tester modified for use on rigid polyurethane foam. Provides objective basis for evaluation of improvements in foam manufacturing and inspection. Typical acceptance criterion requires minimum hardness reading of 80 on modified tester. With adequate correlation tests, modified tester used to measure indirectly tensile and compressive strengths of foam.

  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. Dynamic hardness of metals

    Science.gov (United States)

    Liang, Xuecheng

    Dynamic hardness (Pd) of 22 different pure metals and alloys having a wide range of elastic modulus, static hardness, and crystal structure were measured in a gas pulse system. The indentation contact diameter with an indenting sphere and the radius (r2) of curvature of the indentation were determined by the curve fitting of the indentation profile data. r 2 measured by the profilometer was compared with that calculated from Hertz equation in both dynamic and static conditions. The results indicated that the curvature change due to elastic recovery after unloading is approximately proportional to the parameters predicted by Hertz equation. However, r 2 is less than the radius of indenting sphere in many cases which is contradictory to Hertz analysis. This discrepancy is believed due to the difference between Hertzian and actual stress distributions underneath the indentation. Factors which influence indentation elastic recovery were also discussed. It was found that Tabor dynamic hardness formula always gives a lower value than that directly from dynamic hardness definition DeltaE/V because of errors mainly from Tabor's rebound equation and the assumption that dynamic hardness at the beginning of rebound process (Pr) is equal to kinetic energy change of an impact sphere over the formed crater volume (Pd) in the derivation process for Tabor's dynamic hardness formula. Experimental results also suggested that dynamic to static hardness ratio of a material is primarily determined by its crystal structure and static hardness. The effects of strain rate and temperature rise on this ratio were discussed. A vacuum rotating arm apparatus was built to measure Pd at 70, 127, and 381 mum sphere sizes, these results exhibited that Pd is highly depended on the sphere size due to the strain rate effects. P d was also used to substitute for static hardness to correlate with abrasion and erosion resistance of metals and alloys. The particle size effects observed in erosion were

  3. 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.

  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 and Soft

    OpenAIRE

    Claes H. de Vreese; Boomgaarden, Hajo G.; Semetko, Holli A.

    2008-01-01

    Abstract Support for European integration is a function no longer only of `hard' economic and utilitarian predictors but also of `soft' predictors such as feelings of identity and attitudes towards immigrants. Focusing on the issue of the potential membership of Turkey in the European Union (EU), this study demonstrates that the importance of `soft' predictors outweighs the role of `hard' predictors in understanding public opinion about Turkish membership. The study draws on survey...

  6. Hardness amplification in nondeterministic logspace

    OpenAIRE

    Gupta, Sushmita

    2007-01-01

    A hard problem is one which cannot be easily computed by efficient algorithms. Hardness amplification is a procedure which takes as input a problem of mild hardness and returns a problem of higher hardness. This is closely related to the task of decoding certain error-correcting codes. We show amplification from mild average case hardness to higher average case hardness for nondeterministic logspace and worst-to-average amplification for nondeterministic linspace. Finally we explore possible ...

  7. Hard and superhard nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J. [Univ. of West Bohemia, Plzen (Czech Republic). Dept. of Phys.

    2000-03-01

    This article reviews the development of hard coatings from a titanium nitride film through superlattice coatings to nanocomposite coatings. Significant attention is devoted to hard and superhard single layer nanocomposite coatings. A strong correlation between the hardness and structure of nanocomposite coatings is discussed in detail. Trends in development of hard nanocomposite coatings are also outlined. (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. 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.)

  10. 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.

  11. Hard-hat day

    CERN Multimedia

    2003-01-01

    CERN will be organizing a special information day on Friday, 27th June, designed to promote the wearing of hard hats and ensure that they are worn correctly. A new prevention campaign will also be launched.The event will take place in the hall of the Main Building from 11.30 a.m. to 2.00 p.m., when you will be able to come and try on various models of hard hat, including some of the very latest innovative designs, ask questions and pass on any comments and suggestions.

  12. 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

  13. Budgeting in Hard Times.

    Science.gov (United States)

    Parrino, Frank M.

    2003-01-01

    Interviews with school board members and administrators produced a list of suggestions for balancing a budget in hard times. Among these are changing calendars and schedules to reduce heating and cooling costs; sharing personnel; rescheduling some extracurricular activities; and forming cooperative agreements with other districts. (MLF)

  14. CSI: Hard Drive

    Science.gov (United States)

    Sturgeon, Julie

    2008-01-01

    Acting on information from students who reported seeing a classmate looking at inappropriate material on a school computer, school officials used forensics software to plunge the depths of the PC's hard drive, searching for evidence of improper activity. Images were found in a deleted Internet Explorer cache as well as deleted file space.…

  15. 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,…

  16. Hard times; Schwere Zeiten

    Energy Technology Data Exchange (ETDEWEB)

    Grunwald, Markus

    2012-10-02

    The prices of silicon and solar wafers keep dropping. According to market research specialist IMS research, this is the result of weak traditional solar markets and global overcapacities. While many manufacturers are facing hard times, big producers of silicon are continuing to expand.

  17. 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.

  18. Theory of hard photoproduction

    OpenAIRE

    Klasen, Michael

    2002-01-01

    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...

  19. Theory of hard photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2002-06-01

    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.)

  20. 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)

  1. Hard and Soft Governance

    DEFF Research Database (Denmark)

    Moos, Lejf

    2009-01-01

    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......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...... 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 focus...

  2. 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.

  3. 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…

  4. Why All the Hard Work?

    Institute of Scientific and Technical Information of China (English)

    VALERIE; SARTOR

    2011-01-01

    The stereotype of the hard working Chinese has been around for a long time in the West. As early a 1894, Arthur Smith, a missionary who spent 54 years in China, wrote book introducing the hard-working Chinese people to Americans. In his book Chinese Characteristics, Smith wrote about the dili

  5. Phase behavior of hard particles

    NARCIS (Netherlands)

    Duijneveldt, J.S. van; Lekkerkerker, H.N.W.

    1995-01-01

    The phase behavior of hard particles and mixtures thereof is reviewed. Special attention is given to a lattice model consisting of hard hexagons and points on a triangular lattice. This model appears to have two disordered phases and an ordered phase.

  6. 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

  7. 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.

  8. Unified approach to hard diffraction

    CERN Document Server

    Peschanski, R

    2001-01-01

    Using a combination of S-Matrix and perturbative QCD properties in the small x_{Bj} regime, we propose a formulation of hard diffraction unifying the partonic (Ingelman-Schlein) Pomeron, Soft Colour Interaction and QCD dipole descriptions.

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tash, M. [Universite du Quebec a Chicoutimi, Chicoutimi, Quebec (Canada); Cairo University, Giza (Egypt); Samuel, F.H. [Universite du Quebec a Chicoutimi, Chicoutimi, Quebec (Canada)]. E-mail: fhsamuel@uqac.ca; Mucciardi, F. [McGill University, Montreal, Quebec (Canada); Doty, H.W. [General Motors Powertrain Group, Metal Casting Technology, Inc., Milford, NH (United States)

    2007-01-15

    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

  11. Hard Diffraction at D{phi}

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Gilvan A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Lab. de Cosmologia e Fisica Experimental de Altas Energias

    2000-07-01

    Full text follows: We review recent Hard Diffraction results from the D{phi} experiment at Fermilab, for the following processes: hard color singlet exchange, hard single diffraction, and hard double pomeron exchange. Measurements of rates, {eta}, E{sub T} and {radical}S dependencies are presented and comparisons made with predictions of several models. (author)

  12. 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.

  13. 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 low-- and high--mass soft diffraction and present a new model for hard diffraction in pp and ppbar collisions. Both models uses the Pomeron approach pioneered by Ingelman and Schlein, factorising the single diffractive cross section into a Pomeron flux and a Pomeron PDF. The model for hard diffraction is implemented as a part of the multiparton interactions framework, thereby introducing a dynamical rapidity gap survival probability that explicitly breaks factorisation.

  14. 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.

  15. 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.

  16. 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

  17. Inclusive Hard Diffraction at HERA

    CERN Document Server

    Proskuryakov, Alexander

    2010-01-01

    Recent data from the H1 and ZEUS experiments on hard inclusive diffraction are discussed. Results of QCD analyses of the diffractive deep-inelastic scattering processes are reported. Predictions based on the extracted parton densities are compared to diffractive dijet measurements.

  18. 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…

  19. Hard Trying and These Recipes

    Science.gov (United States)

    Atwell, Nancie

    2003-01-01

    Writers thrive when they are motivated to work hard, have regular opportunities to practice and reflect, and benefit from a knowledgeable teacher who knows writing. Student feedback to lessons during writing workshop helped guide Nancie Atwell in her quest to provide the richest and most efficient path to better writing.

  20. Unifying approach to hard diffraction

    CERN Document Server

    Navelet, H

    2001-01-01

    We find a formulation of hard diffraction unifying the partonic (Ingelman-Schlein) Pomeron, Soft Colour Interaction and QCD dipole descriptions. A theoretical interpretation in terms of S-Matrix and perturbative QCD properties in the small x_{Bj} regime is proposed.

  1. Hard sphere packings within cylinders.

    Science.gov (United States)

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

    2016-03-07

    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.

  2. Hard sphere model of atom

    CERN Document Server

    Tsekov, R

    2014-01-01

    The finite size effect of electron and nucleus is accounted for in the model of atom. Due to their hard sphere repulsion the energy of the 1s orbital decreases and the corrections amount up to 8 % in Uranium. Several models for boundary conditions on the atomic nucleus surface are discussed as well.

  3. 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

  4. Hard processes in hadronic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Satz, H. [CERN, Geneva (Switzerland)]|[Universitat Bielefeld (Germany); Wang, X.N. [Lawrence Berkeley Lab., CA (United States)

    1995-07-01

    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, we discuss the present theoretical understanding, compare the resulting predictions to available data, and then show what behaviour 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 and 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 andin July 1994 at LBL in Berkeley.

  5. Ultrasonic material hardness depth measurement

    Science.gov (United States)

    Good, Morris S.; Schuster, George J.; Skorpik, James R.

    1997-01-01

    The invention is an ultrasonic surface hardness depth measurement apparatus and method permitting rapid determination of hardness depth of shafts, rods, tubes and other cylindrical parts. The apparatus of the invention has a part handler, sensor, ultrasonic electronics component, computer, computer instruction sets, and may include a display screen. The part handler has a vessel filled with a couplant, and a part rotator for rotating a cylindrical metal part with respect to the sensor. The part handler further has a surface follower upon which the sensor is mounted, thereby maintaining a constant distance between the sensor and the exterior surface of the cylindrical metal part. The sensor is mounted so that a front surface of the sensor is within the vessel with couplant between the front surface of the sensor and the part.

  6. Development of Radiation Hard Scintillators

    CERN Document Server

    Tiras, Emrah; Bilki, Burak; Winn, David; Onel, Yasar

    2016-01-01

    Modern high-energy physics experiments are in ever increasing need for radiation hard scintillators and detectors. In this regard, we have studied various radiation-hard scintillating materials such as Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), our prototype material Scintillator X (SX) and Eljen (EJ). Scintillation and transmission properties of these scintillators are studied using stimulated emission from a 334 nm wavelength UV laser with PMT before and after certain amount of radiation exposure. Recovery from radiation damage is studied over time. While the primary goal of this study is geared for LHC detector upgrades, these new technologies could easily be used for future experiments such as the FCC and ILC. Here we discuss the physics motivation, recent developments and laboratory measurements of these materials.

  7. Schwannoma of the hard palate

    OpenAIRE

    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.

  8. 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.

  9. 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 ...

  10. Raman Model Predicting Hardness of Covalent Crystals

    OpenAIRE

    Zhou, Xiang-Feng; Qian, Quang-Rui; Sun, Jian; Tian, Yongjun; Wang, Hui-Tian

    2009-01-01

    Based on the fact that both hardness and vibrational Raman spectrum depend on the intrinsic property of chemical bonds, we propose a new theoretical model for predicting hardness of a covalent crystal. The quantitative relationship between hardness and vibrational Raman frequencies deduced from the typical zincblende covalent crystals is validated to be also applicable for the complex multicomponent crystals. This model enables us to nondestructively and indirectly characterize the hardness o...

  11. 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...

  12. 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...

  13. 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,...

  14. The hard problem of cooperation.

    Directory of Open Access Journals (Sweden)

    Kimmo Eriksson

    Full Text Available Based on individual variation in cooperative inclinations, we define the "hard problem of cooperation" as that of achieving high levels of cooperation in a group of non-cooperative types. Can the hard problem be solved by institutions with monitoring and sanctions? In a laboratory experiment we find that the answer is affirmative if the institution is imposed on the group but negative if development of the institution is left to the group to vote on. In the experiment, participants were divided into groups of either cooperative types or non-cooperative types depending on their behavior in a public goods game. In these homogeneous groups they repeatedly played a public goods game regulated by an institution that incorporated several of the key properties identified by Ostrom: operational rules, monitoring, rewards, punishments, and (in one condition change of rules. When change of rules was not possible and punishments were set to be high, groups of both types generally abided by operational rules demanding high contributions to the common good, and thereby achieved high levels of payoffs. Under less severe rules, both types of groups did worse but non-cooperative types did worst. Thus, non-cooperative groups profited the most from being governed by an institution demanding high contributions and employing high punishments. Nevertheless, in a condition where change of rules through voting was made possible, development of the institution in this direction was more often voted down in groups of non-cooperative types. We discuss the relevance of the hard problem and fit our results into a bigger picture of institutional and individual determinants of cooperative behavior.

  15. 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.

  16. Sampling hard to reach populations.

    Science.gov (United States)

    Faugier, J; Sargeant, M

    1997-10-01

    Studies on 'hidden populations', such as homeless people, prostitutes and drug addicts, raise a number of specific methodological questions usually absent from research involving known populations and less sensitive subjects. This paper examines the advantages and limitations of nonrandom methods of data collection such as snowball sampling. It reviews the currently available literature on sampling hard to reach populations and highlights the dearth of material currently available on this subject. The paper also assesses the potential for using these methods in nursing research. The sampling methodology used by Faugier (1996) in her study of prostitutes, HIV and drugs is used as a current example within this context.

  17. 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.

  18. Thermopile detector radiation hard readout

    Science.gov (United States)

    Gaalema, Stephen; Van Duyne, Stephen; Gates, James L.; Foote, Marc C.

    2010-08-01

    The NASA Jupiter Europa Orbiter (JEO) conceptual payload contains a thermal instrument with six different spectral bands ranging from 8μm to 100μm. The thermal instrument is based on multiple linear arrays of thermopile detectors that are intrinsically radiation hard; however, the thermopile CMOS readout needs to be hardened to tolerate the radiation sources of the JEO mission. Black Forest Engineering is developing a thermopile readout to tolerate the JEO mission radiation sources. The thermal instrument and ROIC process/design techniques are described to meet the JEO mission requirements.

  19. 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.

  20. Hard Fault Analysis of Trivium

    CERN Document Server

    Yupu, Hu; Yiwei, Zhang

    2009-01-01

    Fault analysis is a powerful attack to stream ciphers. Up to now, the major idea of fault analysis is to simplify the cipher system by injecting some soft faults. We call it soft fault analysis. As a hardware-oriented stream cipher, Trivium is weak under soft fault analysis. In this paper we consider another type of fault analysis of stream cipher, which is to simplify the cipher system by injecting some hard faults. We call it hard fault analysis. We present the following results about such attack to Trivium. In Case 1 with the probability not smaller than 0.2396, the attacker can obtain 69 bits of 80-bits-key. In Case 2 with the probability not smaller than 0.2291, the attacker can obtain all of 80-bits-key. In Case 3 with the probability not smaller than 0.2291, the attacker can partially solve the key. In Case 4 with non-neglectable probability, the attacker can obtain a simplified cipher, with smaller number of state bits and slower non-linearization procedure. In Case 5 with non-neglectable probability,...

  1. Hard rock, heavy metal, metal

    OpenAIRE

    Hein, Fabien

    2011-01-01

    Le terme générique metal désigne une multitude de genres et de sous-genres musicaux issus de l’appariement du hard rock et du heavy metal. Il résulte d’une agrégation sémantique consécutive de l’érosion et de l’interpénétration de ces termes au cours des années 1980. Leurs modèles canoniques, respectivement représentés par les groupes Led Zeppelin et Black Sabbath, se sont progressivement dilués sous l’effet d’une filiation particulièrement effervescente et féconde : black, thrash, doom, prog...

  2. Probing Strangeness in Hard Processes

    CERN Document Server

    Avakian, H; Cisbani, E; Contalbrigo, M; D'Alesio, U; De Leo, R; Devita, R; Di Nezza, P; Hasch, D; Mirazita, M; Osipenko, M; Pappalardo, L; Rossi, P

    2012-01-01

    Since the discovery of strangeness almost five decades ago, interest in this degree of freedom has grown up and now its investigation spans the scales from quarks to nuclei. Measurements with identified strange hadrons can provide important information on several hot topics in hadronic physics: the strange distribution and fragmentation functions, the nucleon tomography and quark orbital momentum, accessible through the study of the {\\it generalized} parton distribution and the {\\it transverse momentum dependent} parton distribution functions, the quark hadronization in the nuclear medium, the hadron spectroscopy and the search for exotic mesons. The CLAS12 large acceptance spectrometer in Hall B at the Jefferson Laboratory upgraded with a RICH detector together with the 12 GeV CEBAF high intensity, high polarized electron beam can open new possibilities to study strangeness in hard processes allowing breakthroughs in all those areas. This paper summarizes the physics case for a RICH detector for CLAS12. Many...

  3. 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.

  4. Schwannoma of the hard palate.

    Science.gov (United States)

    Isildak, Huseyin; Yilmaz, Mehmet; Ibrahimov, Metin; Aslan, Mehmet; Karaman, Emin; Enver, Ozgun

    2010-01-01

    About half of all neurogenic tumors are seen in the head and neck region. The types of neurogenic tumors must be distinguished. Schwannomas originate from Schwann cells of the neural sheath and are solitary, well-encapsulated, slow-growing adjacent to the parental nerve but extrinsic to the nerve fascicles.Approximately 25% to 45% of all schwannomas are seen in the head and neck region and are found rarely in the oral cavity. Most of the intraoral schwannomas are located in the tongue. Other less common locations are the buccal mucosa, palate, base of the mouth, gingiva, and lips.In this study, we report a rare case of schwannoma of the hard palate, which was excised intraorally.

  5. Hardness measures and resolution lower bounds

    OpenAIRE

    Beyersdorff, Olaf; Kullmann, Oliver

    2013-01-01

    Various "hardness" measures have been studied for resolution, providing theoretical insight into the proof complexity of resolution and its fragments, as well as explanations for the hardness of instances in SAT solving. In this report we aim at a unified view of a number of hardness measures, including different measures of width, space and size of resolution proofs. We also extend these measures to all clause-sets (possibly satisfiable).

  6. Unified characterisations of resolution hardness measures

    OpenAIRE

    Beyersdorff, O; Kullmann, O.

    2014-01-01

    Various "hardness" measures have been studied for resolution, providing theoretical insight into the proof complexity of resolution and its fragments, as well as explanations for the hardness of instances in SAT solving. In this paper we aim at a unified view of a number of hardness measures, including different measures of width, space and size of resolution proofs. Our main contribution is a unified game-theoretic characterisation of these measures. As consequences we obtain new relations b...

  7. 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).

  8. 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.

  9. Retraction of Hard, Lozano, and Tversky (2006)

    Science.gov (United States)

    Hard, B. M.; Lozano, S. C.; Tversky, B.

    2008-01-01

    Reports a retraction of "Hierarchical encoding of behavior: Translating perception into action" by Bridgette Martin Hard, Sandra C. Lozano and Barbara Tversky (Journal of Experimental Psychology: General, 2006[Nov], Vol 135[4], 588-608). All authors retract this article. Co-author Tversky and co-author Hard believe that the research results cannot…

  10. Hard Spring Wheat Technical Committee 2016 Crop

    Science.gov (United States)

    Seven experimental lines of hard spring wheat were grown at up to five locations in 2016 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Wheat samples were submitted through the Wheat Quality Council and processed and milled at the USDA-ARS Hard Red Spri...

  11. Hardness methods for testing maize kernels.

    Science.gov (United States)

    Fox, Glen; Manley, Marena

    2009-07-08

    Maize is a highly important crop to many countries around the world, through the sale of the maize crop to domestic processors and subsequent production of maize products and also provides a staple food to subsistance farms in undeveloped countries. In many countries, there have been long-term research efforts to develop a suitable hardness method that could assist the maize industry in improving efficiency in processing as well as possibly providing a quality specification for maize growers, which could attract a premium. This paper focuses specifically on hardness and reviews a number of methodologies as well as important biochemical aspects of maize that contribute to maize hardness used internationally. Numerous foods are produced from maize, and hardness has been described as having an impact on food quality. However, the basis of hardness and measurement of hardness are very general and would apply to any use of maize from any country. From the published literature, it would appear that one of the simpler methods used to measure hardness is a grinding step followed by a sieving step, using multiple sieve sizes. This would allow the range in hardness within a sample as well as average particle size and/or coarse/fine ratio to be calculated. Any of these parameters could easily be used as reference values for the development of near-infrared (NIR) spectroscopy calibrations. The development of precise NIR calibrations will provide an excellent tool for breeders, handlers, and processors to deliver specific cultivars in the case of growers and bulk loads in the case of handlers, thereby ensuring the most efficient use of maize by domestic and international processors. This paper also considers previous research describing the biochemical aspects of maize that have been related to maize hardness. Both starch and protein affect hardness, with most research focusing on the storage proteins (zeins). Both the content and composition of the zein fractions affect

  12. Theoretical Hardness of Wurtzite-Structured Semiconductors

    Institute of Scientific and Technical Information of China (English)

    GUO Xiao-Ju; XU Bo; LIU Zhong-Yuan; YU Dong-Li; HE Ju-Long; GUO Li-Cong

    2008-01-01

    Vickers hardness calculations of eleven wurtzite-structured semiconductors are performed based on the microscopic hardness model All the parameters are obtained from first-principles calculations. There axe two types of chemical bonds in wurtzite-structured crystals. The overlap populations of the two types of chemical bonds in lonsdaleite are chosen as Pc for wurtzite structure. The calculated bond ionicity values of the wurtzite-structured semiconductors are in good agreement with the ionicities from the dielectric definition. When the hardness of wurtzite-structured crystal is higher than 20GPa, our calculated Vickers hardness is within 10% accuracy. Therefore, the hardness of novel wurtzite-structured crystal could be estimated from first-principles calculations.

  13. Selection of Nepalese Timber for Small Wind Turbine Blade Construction

    DEFF Research Database (Denmark)

    Sinha, R.; Acharya, Parash; Freere, Peter

    2010-01-01

    , weathering effect on coatings, price, growth and availability of the timber. Mechanical properties such as Young's modulus of elasticity, breaking strength, breaking strain and Brinell's hardness of selected Nepalese timbers are presented. The effects of weathering on timbers without coating...

  14. 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.

  15. Why Is It So Hard to Quit?

    Science.gov (United States)

    ... to quit? It’s hard to tackle the physical addiction to nicotine . Cigarettes contain nicotine, a highly addictive ... a support group can give you comfort and positive reinforcement. Cut back on caffeine . Caffeine is a ...

  16. 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...

  17. Optical waveguides in hard crystalline materials

    NARCIS (Netherlands)

    Pollnau, M.

    2005-01-01

    The recent results of our research group and collaborators in the field of fabrication, characterization, and applications of optical waveguides in hard crystalline materials, specifically in sapphire and Ti:sapphire, are reviewed.

  18. A Novel Approach to Hardness Testing

    Science.gov (United States)

    Spiegel, F. Xavier; West, Harvey A.

    1996-01-01

    This paper gives a description of the application of a simple rebound time measuring device and relates the determination of relative hardness of a variety of common engineering metals. A relation between rebound time and hardness will be sought. The effect of geometry and surface condition will also be discussed in order to acquaint the student with the problems associated with this type of method.

  19. Point defects in hard-sphere crystals

    OpenAIRE

    Pronk, S.; Frenkel, D.

    2001-01-01

    We report numerical calculations of the concentration of interstitials in hard-sphere crystals. We find that, in a three-dimensional fcc hard-sphere crystal at the melting point, the concentration of interstitials is 2 * 10^-8. This is some three orders of magnitude lower than the concentration of vacancies. A simple, analytical estimate yields a value that is in fair agreement with the numerical results.

  20. The Chiral Dipolar Hard Sphere Model.

    OpenAIRE

    Mazars, Martial

    2009-01-01

    Abstract A simple molecular model of chiral molecules is presented in this paper : the chiral dipolar hard sphere model. The discriminatory interaction between enantiomers is represented by electrostatic (or magnetic) dipoles-dipoles interactions : short ranged steric repulsion are represented by hard sphere potential and, in each molecule, two point dipoles are located inside the sphere. The model is described in detail and some of its elementary properties are given ; in particul...

  1. Hardness and Methods to Solve CLIQUE

    Institute of Scientific and Technical Information of China (English)

    ZHU Daming; LUAN Junfeng; MA Shaohan

    2001-01-01

    The paper briefly reviews NP-hard optimization problems and their inapproximability. The hardness of solving CLIQUE problem is specifically discussed. A dynamic-programming algorithm and its improved version for CLIQUE are reviewed and some additional analysis is presented. The analysis implies that the improved algorithm, HEWN (hierarchical edge-weighted network), only provides a heuristic or useful method, but cannot be called a polynomial algorithm.

  2. 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...

  3. Hard and Soft Multilayered SiCN Nanocoatings with High Hardness and Toughness

    Directory of Open Access Journals (Sweden)

    S. K. Mishra

    2013-01-01

    Full Text Available Alternate hard and soft layers increase deformation accommodation as thin hard layers slide relative to each other due to shear deformation of low modulus layers. However, the processing of such multilayers is challenging. In the present paper the alternating soft and hard multilayered SiCN coating deposited by magnetron sputtering has been studied and presented. A hardness and modulus of 37 GPa and 317 GPa with elastic recovery of 62% are achieved by alternate hard and soft layer of Si–C–N by magnetron sputtering. The trilayer films sustained even 2000 gf under indentation without failure though substrate plastically deformed. The fracture toughness value KIC was measured to be 9.5–10 MPa m1/2, significantly higher than many reported hard coatings.

  4. Developing and Studying the Methods of Hard-Facing with Heat-Resisting High-Hardness Steels

    Science.gov (United States)

    Malushin, N. N.; Kovalev, A. P.; Valuev, D. V.; Shats, E. A.; Borovikov, I. F.

    2016-08-01

    The authors develop the methods of hard-facing of mining-metallurgic equipment parts with heat-resisting high-hardness steels on the base of plasma-jet hard-facing in the shielding-alloying nitrogen atmosphere.

  5. Hard Water and Soft Soap: Dependence of Soap Performance on Water Hardness

    Science.gov (United States)

    Osorio, Viktoria K. L.; de Oliveira, Wanda; El Seoud, Omar A.; Cotton, Wyatt; Easdon, Jerry

    2005-01-01

    The demonstration of the performance of soap in different aqueous solutions, which is due to water hardness and soap formulation, is described. The demonstrations use safe, inexpensive reagents and simple glassware and equipment, introduce important everyday topics, stimulates the students to consider the wider consequences of water hardness and…

  6. Research in the Hard Sciences, and in Very Hard "Softer" Domains

    Science.gov (United States)

    Phillips, D. C.

    2014-01-01

    The author of this commentary argues that physical scientists are attempting to advance knowledge in the so-called hard sciences, whereas education researchers are laboring to increase knowledge and understanding in an "extremely hard" but softer domain. Drawing on the work of Popper and Dewey, this commentary highlights the relative…

  7. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    in the vertical and horizontal directions was addressed. A functioning prototype of a 2D silicon objective for use in a bright-field hard-XRM was demonstrated. The results are promising; showing acceptably low aberration and performance close to theoretical expectations. A resolution of 300 nm with 17 keV x......This thesis deals with the development of silicon compound refractive lenses (Si-CRLs) for shaping hard x-ray beams. The CRLs are to be fabricated using state of the art microfabrication techniques. The primary goal of the thesis work is to produce Si-CRLs with considerably increased structure...... intense and wider line beams with narrower waists. The thesis starts with a review of alternative x-ray lenses. Si-CRLs are identified as valuable optical components that allow shaping hard x-rays efficiently and creating beam waists that are clearly in the nanometer range. They stand out...

  8. Hard template synthesis of metal nanowires

    Directory of Open Access Journals (Sweden)

    Go eKawamura

    2014-11-01

    Full Text Available Metal nanowires (NWs have attracted much attention because of their high electron conductivity, optical transmittance and tunable magnetic properties. Metal NWs have been synthesized using soft templates such as surface stabilizing molecules and polymers, and hard templates such as anodic aluminum oxide, mesoporous oxide, carbon nanotubes. NWs prepared from hard templates are composites of metals and the oxide/carbon matrix. Thus, selecting appropriate elements can simplify the production of composite devices. The resulting NWs are immobilized and spatially arranged, as dictated by the ordered porous structure of the template. This avoids the NWs from aggregating, which is common for NWs prepared with soft templates in solution. Herein, the hard template synthesis of metal NWs is reviewed, and the resulting structures, properties and potential applications are discussed.

  9. UV curable hard coatings on polyesters

    Science.gov (United States)

    Datashvili, Tea; Brostow, Witold; Kao, David

    2006-10-01

    UV curable, hard and transparent hybrid inorganic-organic coatings with covalent links between the inorganic and the organic networks were prepared using organically crosslinked heteropolysiloxanes based on the sol-gel process. The materials were applied onto polyester sheets and UV cured. The deposition was followed by a thermal treatment to improve mechanical properties of the coatings. High light transmission and the resulting thermophysical properties indicate the presence of a nanoscale hybrid composition. The coatings show excellent adhesion to polyesters even without using primers. Further mechanical characterization shows that the coatings provide high hardness and good abrasion resistance.

  10. Hardness and incipient plasticity in silicate glasses

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Smedskjær, Morten Mattrup; Mauro, John C.;

    2014-01-01

    The scaling of Vickers hardness (Hv) in oxide glasses with varying network modifier/modifier ratio is manifested as either a positive or negative deviation from linearity with a maximum deviation at the ratio of about 1:1. In an earlier study [J. Kjeldsen et al., J. Non-Cryst. Solids 369,61(2013)......The scaling of Vickers hardness (Hv) in oxide glasses with varying network modifier/modifier ratio is manifested as either a positive or negative deviation from linearity with a maximum deviation at the ratio of about 1:1. In an earlier study [J. Kjeldsen et al., J. Non-Cryst. Solids 369...

  11. Comparison of different hardness definitions usable for micro- and nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Pohlenz, F.; Herrmann, K.; Seemann, R.; Menelao, F. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2001-09-01

    In order to describe the hardness of substrates and layers, different definitions are used which consider the plastic or the elastic-plastic behavior of the material. For a chosen spectrum of substrate and layer materials the absolute hardness values according to these definitions are compared with each other. Moreover, relationships between the hardness values are derived. For the investigation of differences in the accuracy of the various hardness definitions the variance coefficients of different hardnesses were determined. (orig.)

  12. Remember Hard but Think Softly: Metaphorical Effects of Hardness/Softness on Cognitive Functions

    Directory of Open Access Journals (Sweden)

    Jiushu Xie

    2016-09-01

    Full Text Available Previous studies have found that bodily stimulation, such as hardness, biases social judgment and evaluation via metaphorical association; however, it remains unclear whether bodily stimulation also affects cognitive functions, such as memory and creativity. The current study used metaphorical associations between hard and rigid and between soft and flexible in Chinese, to investigate whether the experience of hardness affected cognitive functions requiring either rigidity (memory or flexibility (creativity. In Experiment 1, we found that Chinese-speaking participants performed better at recalling previously memorized words while sitting on a hard-surface stool (the hard condition than a cushioned one (the soft condition. In Experiment 2, participants sitting on a cushioned stool outperformed those sitting on a hard-surface stool on a Chinese riddle task, which required creative/flexible thinking, but not on an analogical reasoning task, which required both rigid and flexible thinking. The results suggest the hardness experience affects cognitive functions that are metaphorically associated with rigidity and flexibility. They support the embodiment proposition that cognitive functions and representations could be grounded via metaphorical association in bodily states.

  13. Radiation-Hardness Data For Semiconductor Devices

    Science.gov (United States)

    Price, W. E.; Nichols, D. K.; Brown, S. F.; Gauthier, M. K.; Martin, K. E.

    1984-01-01

    Document presents data on and analysis of radiation hardness of various semiconductor devices. Data specifies total-dose radiation tolerance of devices. Volume 1 of report covers diodes, bipolar transistors, field effect transistors, silicon controlled rectifiers and optical devices. Volume 2 covers integrated circuits. Volume 3 provides detailed analysis of data in volumes 1 and 2.

  14. Ototraumatic effects of hard rock music.

    Science.gov (United States)

    Reddell, R C; Lebo, C P

    1972-01-01

    Temporary and permanent shifts in auditory thresholds were found in 43 hard rock musicians and temporary shifts were also observed in some listeners. The threshold shifts involved all of the conventional puretone test frequencies. Custom-fitted polyvinyl chloride ear protectors were found to be effective in prevention of these noise-induced hearing losses.

  15. Stability of Hardly Reshaping Berm Breakwaters

    DEFF Research Database (Denmark)

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

    2012-01-01

    in the surging wave area. Moreover, a simple method to estimate the erosion area based on recession formulae and the depth of intersection of reshaped and initial profile is presented and is applicable for hardly reshaping to fully reshaping. Even when using the only very simple and inaccurate estimate...

  16. Imaging in Hard X-ray Astronomy

    CERN Document Server

    Li Ti Pei

    2002-01-01

    The energy range of hard X-rays is a key waveband to the study of high energy processes in celestial objects, but still remains poorly explored. In contrast to direct imaging methods used in the low energy X-ray and high energy gamma-ray bands, currently imaging in the hard X-ray band is mainly achieved through various modulation techniques. A new inversion technique, the direct demodulation method, has been developed since early 90s. With this technique, wide field and high resolution images can be derived from scanning data of a simple collimated detector. The feasibility of this technique has been confirmed by experiment, balloon-borne observation and analyzing simulated and real astronomical data. Based the development of methodology and instrumentation, a high energy astrophysics mission -- Hard X-ray Modulation Telescope (HXMT) has been proposed and selected in China for a four-year Phase-A study. The main scientific objectives are a full-sky hard X-ray (20-200 keV) imaging survey and high signal-to-noi...

  17. Hardness of basaltic glass-ceramics

    DEFF Research Database (Denmark)

    Jensen, Martin; Smedskjær, Morten Mattrup; Estrup, Maja;

    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...

  18. Hard scattering in {gamma}p interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, T.; Andreev, V.; Andrieu, B.; Arpagaus, M.; Babayev, A.; Baerwolff, H.; Ban, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Beck, G.A.; Beck, H.P.; Behrend, H.J.; Belousov, A.; Berger, C.; Bergstein, H.; Bernardi, G.; Bernet, R.; Bertrand-Coremans, G.; Besancon, M.; Biddulph, P.; Binder, E.; Bizot, J.C.; Blobel, V.; Borras, K.; Bosetti, P.C.; Boudry, V.; Bourdarios, C.; Brasse, F.; Braun, U.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Buerger, J.; Buesser, F.W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A.J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A.B.; Colombo, M.; Coughlan, J.A.; Courau, A.; Coutures, C.; Cozzika, G.; Criegee, L.; Cvach, J.; Dainton, J.B.; Danilov, M.; Dann, A.W.E.; Dau, W.D.; David, M.; Deffur, E.; Delcourt, B.; DelBuono, L.; Devel, M.; DeRoeck, A.; Dingus, P.; Dollfus, C.; Dowell, J.D.; Dreis, H.B.; Drescher, A.; Duboc, J.; Duellmann, D.; Duenger, O.; Duhm, H.; Eberle, M.; Ebert, J.; Ebert, T.R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellis, N.N.; Ellison, R.J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Feng, Y.; Fensome, I.F.; Ferencei, J.; Ferrarotto, F.; Flauger, W.; Fleischer, M.; Fluegge, G.; Fomenko, A.; Fomynich, B.; Forbush, M.; Formanek, J.; Foster, J.M.; Franke, G.; Fretwurst, E.; Fuhrmann, P.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gellrich, A.; Gennis, M.; Gensch, U.; Genzel, H.; Gerhards, R.; Gillespie, D.; Godfrey, L.; Goerlach, U.; Goerlich, L.; Goldberg, M.; Goodall, A.M.; Gorelov, I.; Goritchev, P.; Grab, C.; Graessler, H.; Graessler, R.; Greenshaw, T.; Greif, H.; Grindhammer, G.; Gruber, C.; Haack, J.; Haguenauer, M.; Haidt, D.; Hajduk, L.; Hamon, O.; Handschuh, D.; Hanlon, E.M.; Hapke, M.; Harjes, J.; Hartz, P.; Haydar, R.; Haynes, W.J.; Heatherington, J.; Hedberg, V.; Hedgecock, R.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Herma, R.; H1 Collaboration

    1992-10-01

    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.).

  19. Hard Times: Philosophy and the Fundamentalist Imagination

    Science.gov (United States)

    Allsup, Randall Everett

    2005-01-01

    A close reading of Gradgrind's opening monologue of Hard Times by Charles Dickens will provide the starting off point for an examination of the role and place of philosophy in the music curriculum. The Gradgrind philosophy finds easy parallel to current thinking in American education. In the fundamentalist imagination, sources of ambiguity must be…

  20. Parallel Narrative Structure in Paul Harding's "Tinkers"

    Science.gov (United States)

    Çirakli, Mustafa Zeki

    2014-01-01

    The present paper explores the implications of parallel narrative structure in Paul Harding's "Tinkers" (2009). Besides primarily recounting the two sets of parallel narratives, "Tinkers" also comprises of seemingly unrelated fragments such as excerpts from clock repair manuals and diaries. The main stories, however, told…

  1. Hard x-ray telescope mission

    DEFF Research Database (Denmark)

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

    1996-01-01

    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...

  2. Doubly diffracted ray from a hard quarterplane

    DEFF Research Database (Denmark)

    Albertsen, Niels Christian

    2000-01-01

    The scattering of the electromagnetic field from a half wave dipole source around a quarterplane can be calculated from the solutions to two scalar problems, one with a soft quarterplane and one with a hard quarterplane. In both cases, a doubly diffracted ray may exist, but only in the case of th...

  3. 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.

  4. "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...

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

    NARCIS (Netherlands)

    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,

  6. 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.

  7. 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.

  8. 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.

  9. Further links between the maximum hardness principle and the hard/soft acid/base principle: insights from hard/soft exchange reactions.

    Science.gov (United States)

    Chattaraj, Pratim K; Ayers, Paul W; Melin, Junia

    2007-08-07

    Ayers, Parr, and Pearson recently showed that insight into the hard/soft acid/base (HSAB) principle could be obtained by analyzing the energy of reactions in hard/soft exchange reactions, i.e., reactions in which a soft acid replaces a hard acid or a soft base replaces a hard base [J. Chem. Phys., 2006, 124, 194107]. We show, in accord with the maximum hardness principle, that the hardness increases for favorable hard/soft exchange reactions and decreases when the HSAB principle indicates that hard/soft exchange reactions are unfavorable. This extends the previous work of the authors, which treated only the "double hard/soft exchange" reaction [P. K. Chattaraj and P. W. Ayers, J. Chem. Phys., 2005, 123, 086101]. We also discuss two different approaches to computing the hardness of molecules from the hardness of the composing fragments, and explain how the results differ. In the present context, it seems that the arithmetic mean of fragment softnesses is the preferable definition.

  10. 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.

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

    Science.gov (United States)

    Sonntag, Robert; Reinders, Jörn; Rieger, Johannes S; Heitzmann, Daniel W W; Kretzer, J Philippe

    2013-01-01

    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.

  12. Remember Hard But Think Softly: Metaphorical Effects of Hardness/Softness on Cognitive Functions

    Science.gov (United States)

    Xie, Jiushu; Lu, Zhi; Wang, Ruiming; Cai, Zhenguang G.

    2016-01-01

    Previous studies have found that bodily stimulation, such as hardness biases social judgment and evaluation via metaphorical association; however, it remains unclear whether bodily stimulation also affects cognitive functions, such as memory and creativity. The current study used metaphorical associations between “hard” and “rigid” and between “soft” and “flexible” in Chinese, to investigate whether the experience of hardness affects cognitive functions whose performance depends prospectively on rigidity (memory) and flexibility (creativity). In Experiment 1, we found that Chinese-speaking participants performed better at recalling previously memorized words while sitting on a hard-surface stool (the hard condition) than a cushioned one (the soft condition). In Experiment 2, participants sitting on a cushioned stool outperformed those sitting on a hard-surface stool on a Chinese riddle task, which required creative/flexible thinking, but not on an analogical reasoning task, which required both rigid and flexible thinking. The results suggest the hardness experience affects cognitive functions that are metaphorically associated with rigidity or flexibility. They support the embodiment proposition that cognitive functions and representations can be grounded in bodily states via metaphorical associations. PMID:27672373

  13. Is hyper-hardness more chemically relevant than expected?

    Science.gov (United States)

    Morell, Christophe; Grand, André; Toro-Labbé, Alejandro; Chermette, Henry

    2013-07-01

    In this work, the third derivative of the energy with respect to the number of electrons, the so-called hyper-hardness, is investigated to assess whether this quantity has a chemical meaning. To achieve this goal a new working expression for hyper-hardness is developed and analyzed. It transpired from this analysis that hyper-hardness, just like hardness, can measure the reactivity or the stability of electron systems. Interestingly, positive values of hyper-hardness point to quite stable species such as noble gases and molecules. On the other hand, radicals almost always display large negative values of hyper-hardness.

  14. 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.

  15. Hardness/intensity correlations among BATSE bursts

    Science.gov (United States)

    Paciesas, William S.; Pendleton, Geoffrey N.; Kouveliotou, Chryssa; Fishman, Gerald J.; Meegan, Charles A.; Wilson, Robert B.

    1992-01-01

    Conclusions about the nature of gamma-ray bursts derived from the size-frequency distribution may be altered if a significant correlation exists between burst intensity and spectral shape. Moreover, if gamma-ray bursts have a cosmological origin, such a correlation may be expected to result from the expansion of the universe. We have performed a rudimentary search of the BATSE bursts for hardness/intensity correlations. The range of spectral shapes was determined for each burst by computing the ratio of the intensity in the range 100-300 keV to that in 55-300 keV. We find weak evidence for the existence of a correlation, the strongest effect being present when comparing the maximum hardness ratio for each burst with its maximum rate.

  16. Laser thermographic technologies for hard copy recording

    Science.gov (United States)

    Bessmel'tsev, Viktor P.; Baev, Sergej G.

    1995-04-01

    Methods of hard copies recording based on thermal interaction of the beam from CO2 or YAG lasers with various kinds of films on any substrates have been developed. The recording processes are single-step and require no additional development. Among them are: (1) Laser thermodestruction of thin mask layers or of a material surface on any kinds of substrates. (2) Laser thermochemical reactions of thermal decomposition of metal salts in solid state phase on a surface of various hygroscopic substrates. The laser recording devices using the methods, described above have been developed and are manufactured now; they allow one to record hard copies with a size of up to 27 X 31 inches, a resolution of 4000 dpi.

  17. 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.

  18. Hard diffraction with dynamic gap survival

    Science.gov (United States)

    Rasmussen, Christine O.; Sjöstrand, Torbjörn

    2016-02-01

    We present a new framework for the modelling of hard diffraction in pp and poverline{p} collisions. It starts from the the approach pioneered by Ingelman and Schlein, wherein the single diffractive cross section is factorized into a Pomeron flux and a Pomeron PDF. To this it adds a dynamically calculated rapidity gap survival factor, derived from the modelling of multiparton interactions. This factor is not relevant for diffraction in ep collisions, giving non-universality between HERA and Tevatron diffractive event rates. The model has been implemented in P ythia 8 and provides a complete description of the hadronic state associated with any hard single diffractive process. Comparisons with poverline{p} and pp data reveal improvement in the description of single diffractive events.

  19. Hard Diffraction with Dynamic Gap Survival

    CERN Document Server

    Rasmussen, Christine O

    2015-01-01

    We present a new framework for the modelling of hard diffraction in pp and ppbar collisions. It starts from the the approach pioneered by Ingelman and Schlein, wherein the single diffractive cross section is factorized into a Pomeron flux and a Pomeron PDF. To this it adds a dynamically calculated rapidity gap survival factor, derived from the modelling of multiparton interactions. This factor is not relevant for diffraction in ep collisions, giving non-universality between HERA and Tevatron diffractive event rates. The model has been implemented in Pythia 8 and provides a complete description of the hadronic state associated with any hard single diffractive process. Comparisons with ppbar and pp data reveal improvement in the description of single diffractive events.

  20. Quantitative Information Flow - Verification Hardness and Possibilities

    CERN Document Server

    Yasuoka, Hirotoshi

    2010-01-01

    Researchers have proposed formal definitions of quantitative information flow based on information theoretic notions such as the Shannon entropy, the min entropy, the guessing entropy, and channel capacity. This paper investigates the hardness and possibilities of precisely checking and inferring quantitative information flow according to such definitions. We prove that, even for just comparing two programs on which has the larger flow, none of the definitions is a k-safety property for any k, and therefore is not amenable to the self-composition technique that has been successfully applied to precisely checking non-interference. We also show a complexity theoretic gap with non-interference by proving that, for loop-free boolean programs whose non-interference is coNP-complete, the comparison problem is #P-hard for all of the definitions. For positive results, we show that universally quantifying the distribution in the comparison problem, that is, comparing two programs according to the entropy based definit...

  1. "Good-Walker" + QCD dipoles = Hard Diffraction

    CERN Document Server

    Peschanski, R

    1998-01-01

    The Good-Walker mechanism for diffraction is shown to provide a link between total and diffractive structure functions and to be relevant for QCD calculations at small x_{Bj}. For Deep-Inelastic scattering on a small-size target (cf. an onium) the r\\^ ole of Good-Walker ``diffractive eigenstates'' is played by the QCD dipoles appearing in the $1/N_C$ limit of QCD. Hard diffraction is thus related to the QCD tripe-dipole vertex which has been recently identified (and calculated) as being a conformal invariant correlator and/or a closed-string amplitude. An extension to hard diffraction at HERA via $k_T-$factorisation of the proton vertices leads to interesting phenomenology.

  2. SURFACES OF HARD-SPHERE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Dietrich Stoyan

    2014-07-01

    Full Text Available In various situations surfaces appear that are formed by systems of hard spheres. Examples are porous layers as surfaces of sand heaps and biofilms or fracture surfaces of concrete. The present paper considers models where a statistically homogeneous system of hard spheres with random radii is intersected by a plane and the surface is formed by the spheres with centers close to this plane. Formulae are derived for various characteristics of such surfaces: for the porosity profile, i.e. the local porosity in dependence on the distance from the section plane and for the geometry of the sphere caps that look above the section plane.It turns out that these characteristics only depend on the first-order characteristics of the sphere system, its sphere density and the sphere radius distribution.Comparison with empirically studied biofilms shows that the model is realistic.

  3. Hard sludge removal in steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Santibanez, M.; Stoss, J.

    2013-07-01

    One of the majors problems during the life of Nuclear power plants is the efficiency lost in steam generator due to, among issues, the plugging and therefore useless, of tubes which presented possibility of cracking in the future. The hard sludge produced in the steam generators secondary side and deposited on the tube sheet or around the tubes as collar shape are one of the main agent causing this problem, so their elimination is considered a major topic in order to keep the steam generators in an optimum condition along the whole plant life. AREVA is aware of this global problem, therefore a process and tools have been continuously developed since 1995 in order to eliminate the hard deposits in a effective way, with no damage to steam generator's components and adaptable for the different steam generators models existing in the market.

  4. CMS results on soft and hard diffraction

    CERN Document Server

    Obertino, Margherita Maria

    2016-01-01

    The measurement of the soft diffractive cross sections in single- and double-diffractive final states is presented at 7 TeV. Furthermore, also the production of jet-gap-get final states is discussed and the results are interpreted in terms of a hard color singlet exchange. Finally, general features of particle production in single-diffractive enhanced events are shown at 13 TeV.

  5. Dynamic Hardness Tester and Cure Meter

    Science.gov (United States)

    Madigosky, Walter M.; Fiorito, Ralph B.

    1993-01-01

    The Shore hardness tester is used extensively throughout industry to determine the static modulus of materials. The new apparatus described here extends the capability of an indentor-type tester into the dynamic regime, and provides a measurement of the dynamic shear or Young's modulus and loss factor as a function of frequency. The instrument, model and data of typical rubber samples are given and compared to other dynamic measurements.

  6. Radiation Hardness Assurance for Space Systems

    Science.gov (United States)

    Poivey, Christian; Day, John H. (Technical Monitor)

    2002-01-01

    The space radiation environment can lead to extremely harsh operating conditions for on-board electronic box and systems. The characteristics of the radiation environment are highly dependent on the type of mission (date, duration and orbit). Radiation accelerates the aging of the electronic parts and material and can lead to a degradation of electrical performance; it can also create transient phenomena on parts. Such damage at the part level can induce damage or functional failure at electronic box, subsystem, and system levels. A rigorous methodology is needed to ensure that the radiation environment does not compromise the functionality and performance of the electronics during the system life. This methodology is called hardness assurance. It consists of those activities undertaken to ensure that the electronic piece parts placed in the space system perform to their design specifications after exposure to the space environment. It deals with system requirements, environmental definitions, part selection, part testing, shielding and radiation tolerant design. All these elements should play together in order to produce a system tolerant to.the radiation environment. An overview of the different steps of a space system hardness assurance program is given in section 2. In order to define the mission radiation specifications and compare these requirements to radiation test data, a detailed knowledge of the space environment and the corresponding electronic device failure mechanisms is required. The presentation by J. Mazur deals with the Earth space radiation environment as well as the internal environment of a spacecraft. The presentation by J. Schwank deals with ionization effects, and the presentation by T. Weatherford deals with Single particle Event Phenomena (SEP) in semiconductor devices and microcircuits. These three presentations provide more detailed background to complement the sections 3 and 4. Part selection and categorization are discussed in section

  7. Nanotwinned diamond with unprecedented hardness and stability.

    Science.gov (United States)

    Huang, Quan; Yu, Dongli; Xu, Bo; Hu, Wentao; Ma, Yanming; Wang, Yanbin; Zhao, Zhisheng; Wen, Bin; He, Julong; Liu, Zhongyuan; Tian, Yongjun

    2014-06-12

    Although diamond is the hardest material for cutting tools, poor thermal stability has limited its applications, especially at high temperatures. Simultaneous improvement of the hardness and thermal stability of diamond has long been desirable. According to the Hall-Petch effect, the hardness of diamond can be enhanced by nanostructuring (by means of nanograined and nanotwinned microstructures), as shown in previous studies. However, for well-sintered nanograined diamonds, the grain sizes are technically limited to 10-30 nm (ref. 3), with degraded thermal stability compared with that of natural diamond. Recent success in synthesizing nanotwinned cubic boron nitride (nt-cBN) with a twin thickness down to ∼3.8 nm makes it feasible to simultaneously achieve smaller nanosize, ultrahardness and superior thermal stability. At present, nanotwinned diamond (nt-diamond) has not been fabricated successfully through direct conversions of various carbon precursors (such as graphite, amorphous carbon, glassy carbon and C60). Here we report the direct synthesis of nt-diamond with an average twin thickness of ∼5 nm, using a precursor of onion carbon nanoparticles at high pressure and high temperature, and the observation of a new monoclinic crystalline form of diamond coexisting with nt-diamond. The pure synthetic bulk nt-diamond material shows unprecedented hardness and thermal stability, with Vickers hardness up to ∼200 GPa and an in-air oxidization temperature more than 200 °C higher than that of natural diamond. The creation of nanotwinned microstructures offers a general pathway for manufacturing new advanced carbon-based materials with exceptional thermal stability and mechanical properties.

  8. Circle Packing for Origami Design Is Hard

    CERN Document Server

    Demaine, Erik D; Lang, Robert J

    2010-01-01

    We show that deciding whether a given set of circles can be packed into a rectangle, an equilateral triangle, or a unit square are NP-hard problems, settling the complexity of these natural packing problems. On the positive side, we show that any set of circles of total area 1 can be packed into a square of size 8/pi=2.546... These results are motivated by problems arising in the context of origami design.

  9. Thermal Conductivity Designed Hard Protective Thin Films

    Science.gov (United States)

    2014-05-01

    University of Leoben. After his PhD in 2001 on Materials Science Aspects of Nanocrystalline PVD Hard Coatings in collaboration with the West Bohemian...Vienna University of Technology) Materials Science and Technology Karlsplatz 13 Wien (Vienna) 1040, AUSTRIA EOARD Grant 13-2147 Report Date: May...University of Technology) Materials Science and Technology Karlsplatz 13 Wien (Vienna) 1040, AUSTRIA 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 9

  10. 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.

  11. Unified QCD picture of hard diffraction

    CERN Document Server

    Navelet, H

    2001-01-01

    Using a combination of S-Matrix and perturbative QCD properties in the small x_{Bjorken} regime, we propose a formulation of hard diffraction unifying the partonic (Ingelman-Schlein) Pomeron, Soft Colour Interaction and QCD dipole descriptions. In particular, we show that all three approaches give an unique and mutually compatible formula for the proton diffractive structure functions incorporating perturbative and non perturbative QCD features.

  12. Hard Exclusive Production of Tensor Mesons

    CERN Document Server

    Braun, V M

    2001-01-01

    We point out that hard exclusive production of tensor mesons $f_2(1270)$ with helicity $\\lambda=\\pm 2$ is dominated by the gluon component in the meson wave function and can be used to determine gluon admixture in tensor mesons in a theoretically clean manner. We present a detailed analysis of the tensor meson distribution amplitudes and calculate the transition form factor $\\gamma+\\gamma^*\\to f_2(1270)$ for one real and one virtual photon.

  13. Colour hard-copy from workstation screens

    Science.gov (United States)

    Clayton, C. A.

    It is possible to produce a colour print on the DEC LJ250 inkjet printer of either the entire screen or a portion of the screen from VAXstations, DECstations, SUN workstations and the IKON image display. This document describes how to achieve this with each of the above workstations. The IKONPAINT software which is used to produce colour hard-copy from the IKON screen on the inkjet printer is fully documented in SUN/71 and is not described here.

  14. Phenomenology of hard diffraction at high energies

    CERN Document Server

    Machado, Magno V T

    2016-01-01

    We present some of the topics covered in two lectures under the same title that was given at the "Summer School on High Energy Physics at the LHC: New trends in HEP" in Natal, Brazil. In this contribution we give a brief review on the application of perturbative QCD to the hard diffractive processes. Such reactions involving a hard scale can be understood in terms of quarks and gluons degrees of freedom and have become an useful tool for investigating the low-$x$ structure of the proton and the behavior of QCD in the high-density regime. We start using the information from the $ep$ collisions at HERA concerned to the inclusive diffraction to introduce the concept of diffractive parton distributions. Their interpretation in the resolved pomeron model is addressed and we discuss the limits of diffractive hard-scattering factorization for hadron-hadron collisions. Some examples of phenomenology for the diffractive production of $W/Z$, heavy $Q\\bar{Q}$ and quarkonium in hadron-hadron reactions are presented. We a...

  15. Surgical lasers and hard dental tissue.

    Science.gov (United States)

    Parker, S

    2007-04-28

    The cutting of dental hard tissue during restorative procedures presents considerable demands on the ability to selectively remove diseased carious tissue, obtain outline and retention form and maintain the integrity of supporting tooth tissue without structural weakening. In addition, the requirement to preserve healthy tissue and prevent further breakdown of the restoration places the choice of instrumentation and clinical technique as prime factors for the dental surgeon. The quest for an alternative treatment modality to the conventional dental turbine has been, essentially, patient-driven and has led to the development of various mechanical and chemical devices. The review of the literature has endorsed the beneficial effects of current laser machines. However utopian, there is additional evidence to support the development of ultra-short (nano- and femto-second) pulsed lasers that are stable in use and commercially viable, to deliver more efficient hard tissue ablation with less risk of collateral thermal damage. This paper explores the interaction of laser energy with dental hard tissues and bone and the integration of current laser wavelengths into restorative and surgical dentistry.

  16. New materials for radiation hard semiconductor dectectors

    Science.gov (United States)

    Sellin, P. J.; Vaitkus, J.

    2006-02-01

    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 10 35 cm -2 s -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 radiation hardness studies. Whilst these materials currently show considerable promise for use as radiation hard tracking detectors, their ultimate success will depend on the continued improvement of the availability of high quality material.

  17. Water hardness and urinary stone disease.

    Science.gov (United States)

    Shuster, J; Finlayson, B; Scheaffer, R; Sierakowski, R; Zoltek, J; Dzegede, S

    1982-08-01

    On the macrogeographic scale, a strong negative association exists in the United States between water hardness and urinary stone disease. This investigation studies the association on the microgeographical scale, where it is possible to control for confounding environmental factors. The study was conducted on 2,295 patients from 2 regions: the Carolinas which had soft water and high stone incidence, and the Rockies which had hard water and low stone incidence. Home tap water samples from urinary stone patient hospitalizations were compared with that of controls, concurrent inguinal hernia patient hospitalization. After adjusting for environmental factors, no significant difference (p = 0.59) between the 2 groups was obtained in tap water calcium, magnesium, and sodium concentrations. An incidental but potentially important finding was that those consuming water from a private well had an estimated relative risk of 1.5 (p less than 0.01) compared to those using public water. While no cause-effect relationship is suggested, stone-formers might consider avoiding private well water. On the other hand, water hardness should be a minor concern with respect to stone formation.

  18. Hardness variability in commercial and hardened technologies

    Energy Technology Data Exchange (ETDEWEB)

    Shaneyfelt, M.R.; Winokur, P.S.; Meisenheimer, T.L.; Sexton, F.W.; Roeske, S.B.; Knoll, M.G.

    1994-03-01

    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.

  19. 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...

  20. Fault-Tolerant, Radiation-Hard DSP

    Science.gov (United States)

    Czajkowski, David

    2011-01-01

    Commercial digital signal processors (DSPs) for use in high-speed satellite computers are challenged by the damaging effects of space radiation, mainly single event upsets (SEUs) and single event functional interrupts (SEFIs). Innovations have been developed for mitigating the effects of SEUs and SEFIs, enabling the use of very-highspeed commercial DSPs with improved SEU tolerances. Time-triple modular redundancy (TTMR) is a method of applying traditional triple modular redundancy on a single processor, exploiting the VLIW (very long instruction word) class of parallel processors. TTMR improves SEU rates substantially. SEFIs are solved by a SEFI-hardened core circuit, external to the microprocessor. It monitors the health of the processor, and if a SEFI occurs, forces the processor to return to performance through a series of escalating events. TTMR and hardened-core solutions were developed for both DSPs and reconfigurable field-programmable gate arrays (FPGAs). This includes advancement of TTMR algorithms for DSPs and reconfigurable FPGAs, plus a rad-hard, hardened-core integrated circuit that services both the DSP and FPGA. Additionally, a combined DSP and FPGA board architecture was fully developed into a rad-hard engineering product. This technology enables use of commercial off-the-shelf (COTS) DSPs in computers for satellite and other space applications, allowing rapid deployment at a much lower cost. Traditional rad-hard space computers are very expensive and typically have long lead times. These computers are either based on traditional rad-hard processors, which have extremely low computational performance, or triple modular redundant (TMR) FPGA arrays, which suffer from power and complexity issues. Even more frustrating is that the TMR arrays of FPGAs require a fixed, external rad-hard voting element, thereby causing them to lose much of their reconfiguration capability and in some cases significant speed reduction. The benefits of COTS high

  1. Factors Resulting in Micron Indentation Hardness Descending in Indentation Tests

    Institute of Scientific and Technical Information of China (English)

    Li Min; Chen Weimin

    2009-01-01

    hardness decrease can be bated if the continuous stiffness measurement technique is not adopted; this indicates that the test method itself may also be one of the factors causing the hardness being descended.

  2. A Modified Theoretical Model of Intrinsic Hardness of Crystalline Solids

    OpenAIRE

    Fu-Zhi Dai; Yanchun Zhou

    2016-01-01

    Super-hard materials have been extensively investigated due to their practical importance in numerous industrial applications. To stimulate the design and exploration of new super-hard materials, microscopic models that elucidate the fundamental factors controlling hardness are desirable. The present work modified the theoretical model of intrinsic hardness proposed by Gao. In the modification, we emphasize the critical role of appropriately decomposing a crystal to pseudo-binary crystals, wh...

  3. Visual inspection technology in the hard disc drive industry

    CERN Document Server

    Muneesawang, Paisarn

    2015-01-01

    A presentation of the use of computer vision systems to control manufacturing processes and product quality in the hard disk drive industry. Visual Inspection Technology in the Hard Disk Drive Industry is an application-oriented book borne out of collaborative research with the world's leading hard disk drive companies. It covers the latest developments and important topics in computer vision technology in hard disk drive manufacturing, as well as offering a glimpse of future technologies.

  4. Study of hot hardness characteristics of tool steels

    Science.gov (United States)

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

    1972-01-01

    Hardness measurements of tool steel materials in electric furnace at elevated temperatures and low oxygen environment are discussed. Development of equation to predict short term hardness as function of intial room temperature hardness of steel is reported. Types of steel involved in the process are identified.

  5. TOPSIS Evaluation Method on "Have Both Hard and Soft" Systems

    Institute of Scientific and Technical Information of China (English)

    CHEN Shi-lian

    2001-01-01

    In "Have Both Hard and Soft" systems, the soft targets and hard targets are divided into twodistinct target system. The measured results of soft target system are regarded as a matrix with intervalnumbers. On the basis of Topsis method, we discuss a new Topsis evaluation method on "Have Both Hardand Soft" systems, which combined soft targets with hard targets.

  6. Hard metal lung disease in an oil industry worker.

    Science.gov (United States)

    Bezerra, Patrícia Nunes; Vasconcelos, Ana Giselle Alves; Cavalcante, Lílian Loureiro Albuquerque; Marques, Vanessa Beatriz de Vasconcelos; Nogueira, Teresa Neuma Albuquerque Gomes; Holanda, Marcelo Alcantara

    2009-12-01

    Hard metal lung disease, which manifests as giant cell interstitial pneumonia, is caused by exposure to hard metal dust. We report the case of an oil industry worker diagnosed with hard metal lung disease. The diagnosis was based on the clinical, radiological and anatomopathological analysis, as well as on pulmonary function testing.

  7. 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.

  8. Development of method for evaluating cell hardness and correlation between bacterial spore hardness and durability

    Directory of Open Access Journals (Sweden)

    Nakanishi Koichi

    2012-06-01

    Full Text Available Abstract Background Despite the availability of conventional devices for making single-cell manipulations, determining the hardness of a single cell remains difficult. Here, we consider the cell to be a linear elastic body and apply Young’s modulus (modulus of elasticity, which is defined as the ratio of the repulsive force (stress in response to the applied strain. In this new method, a scanning probe microscope (SPM is operated with a cantilever in the “contact-and-push” mode, and the cantilever is applied to the cell surface over a set distance (applied strain. Results We determined the hardness of the following bacterial cells: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and five Bacillus spp. In log phase, these strains had a similar Young’s modulus, but Bacillus spp. spores were significantly harder than the corresponding vegetative cells. There was a positive, linear correlation between the hardness of bacterial spores and heat or ultraviolet (UV resistance. Conclusions Using this technique, the hardness of a single vegetative bacterial cell or spore could be determined based on Young’s modulus. As an application of this technique, we demonstrated that the hardness of individual bacterial spores was directly proportional to heat and UV resistance, which are the conventional measures of physical durability. This technique allows the rapid and direct determination of spore durability and provides a valuable and innovative method for the evaluation of physical properties in the field of microbiology.

  9. 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.

  10. 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.

  11. Hardware Assisted ROP Detection Mode (HARD Mode)

    Science.gov (United States)

    2013-08-01

    function call. The section of code to where a ROP attack jumps is called a “ gadget ” and a series of gadgets linked sequentially to achieve a result is...that page fault-based decision engine invocation is not effective . With HARD Mode, the goal was to develop a ROP detection mechanism which would protect...viewdoc/summary?doi=10.1.1.120.5702, 2008. [3] “Shacham, Page, et al.”. On the Effectiveness of Address-Space Randomization. In ACM Computer and

  12. 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.

  13. 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).

  14. Evolutionary algorithms for hard quantum control

    Science.gov (United States)

    Zahedinejad, Ehsan; Schirmer, Sophie; Sanders, Barry C.

    2014-09-01

    Although quantum control typically relies on greedy (local) optimization, traps (irregular critical points) in the control landscape can make optimization hard by foiling local search strategies. We demonstrate the failure of greedy algorithms as well as the (nongreedy) genetic-algorithm method to realize two fast quantum computing gates: a qutrit phase gate and a controlled-not gate. We show that our evolutionary algorithm circumvents the trap to deliver effective quantum control in both instances. Even when greedy algorithms succeed, our evolutionary algorithm can deliver a superior control procedure, for example, reducing the need for high time resolution.

  15. Concrete Physics Method for Solving NP hard Problem

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With a NP hard problem given, we may find a equivalent physicalworld. The rule of the changing of the physical states is simply the algorithm for sol ving the original NP hard problem .It is the most natural algorithm for solving NP hard problems. In this paper we deal with a famous example , the well known NP hard problem--Circles Packing. It shows that our algorithm is dramatically very efficient. We are inspired that, the concrete physics algorithm will alway s be very efficient for NP hard problem.

  16. A Modified Theoretical Model of Intrinsic Hardness of Crystalline Solids

    Science.gov (United States)

    Dai, Fu-Zhi; Zhou, Yanchun

    2016-01-01

    Super-hard materials have been extensively investigated due to their practical importance in numerous industrial applications. To stimulate the design and exploration of new super-hard materials, microscopic models that elucidate the fundamental factors controlling hardness are desirable. The present work modified the theoretical model of intrinsic hardness proposed by Gao. In the modification, we emphasize the critical role of appropriately decomposing a crystal to pseudo-binary crystals, which should be carried out based on the valence electron population of each bond. After modification, the model becomes self-consistent and predicts well the hardness values of many crystals, including crystals composed of complex chemical bonds. The modified model provides fundamental insights into the nature of hardness, which can facilitate the quest for intrinsic super-hard materials. PMID:27604165

  17. A Modified Theoretical Model of Intrinsic Hardness of Crystalline Solids.

    Science.gov (United States)

    Dai, Fu-Zhi; Zhou, Yanchun

    2016-09-08

    Super-hard materials have been extensively investigated due to their practical importance in numerous industrial applications. To stimulate the design and exploration of new super-hard materials, microscopic models that elucidate the fundamental factors controlling hardness are desirable. The present work modified the theoretical model of intrinsic hardness proposed by Gao. In the modification, we emphasize the critical role of appropriately decomposing a crystal to pseudo-binary crystals, which should be carried out based on the valence electron population of each bond. After modification, the model becomes self-consistent and predicts well the hardness values of many crystals, including crystals composed of complex chemical bonds. The modified model provides fundamental insights into the nature of hardness, which can facilitate the quest for intrinsic super-hard materials.

  18. A Modified Theoretical Model of Intrinsic Hardness of Crystalline Solids

    Science.gov (United States)

    Dai, Fu-Zhi; Zhou, Yanchun

    2016-09-01

    Super-hard materials have been extensively investigated due to their practical importance in numerous industrial applications. To stimulate the design and exploration of new super-hard materials, microscopic models that elucidate the fundamental factors controlling hardness are desirable. The present work modified the theoretical model of intrinsic hardness proposed by Gao. In the modification, we emphasize the critical role of appropriately decomposing a crystal to pseudo-binary crystals, which should be carried out based on the valence electron population of each bond. After modification, the model becomes self-consistent and predicts well the hardness values of many crystals, including crystals composed of complex chemical bonds. The modified model provides fundamental insights into the nature of hardness, which can facilitate the quest for intrinsic super-hard materials.

  19. Hard Carbon Films Deposited under Various Atmospheres

    Science.gov (United States)

    Wei, M.-K.; Chen, S.-C.; Wu, T. C.; Lee, Sanboh

    1998-03-01

    Using a carbon target ablated with an XeCl-excimer laser under various gas atmospheres at different pressures, hard carbon was deposited on silicon, iron and tungsten carbide substrates. The hardness, friction coefficient, and wear rate of the film against steel are better than pure substrate material, respectively, so that it has potential to be used as a protective coating for micromechanical elements. The influences of gas pressure, gas atmosphere, and power density of laser irradiation on the thermal stability of film were analyzed by means of Raman-spectroscope, time-of-flight method, and optical emission spectrum. It was found that the film deposited under higher pressure has less diamond-like character. The film deposited under rest gas or argon atmosphere was very unstable and looked like a little graphite-like character. The film deposited at high vacuum (10-5 mbar rest gas) was the most stable and looked like the most diamond-like character. The film deposited at higher power density was more diamond-like than that at lower power density.

  20. 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...

  1. Hard And Soft QCD Physics In ATLAS

    Directory of Open Access Journals (Sweden)

    Adomeit Stefanie

    2014-04-01

    Full Text Available Hard and soft QCD results using proton-proton collisions recorded with the ATLAS detector at the LHC are reported. Charged-particle distributions and forward-backward correlations have been studied in low-luminosity minimum bias data taken at centre-of-mass energies of √s = 0.9, 2.36 and 7 TeV. Recent measurements on underlying event characteristics using charged-particle jets are also presented. The results are tested against various phenomenological soft QCD models implemented in Monte-Carlo generators. A summary of hard QCD measurements involving high transverse momentum jets is also given. Inclusive jet and dijet cross-sections have been measured at a centre-of-mass energy of 7 TeV and are compared to expectations based on NLO pQCD calculations corrected for non-perturbative effects as well as to NLO Monte Carlo predictions. Recent studies exploiting jet substructure techniques to identify hadronic decays of boosted massive particles are reported.

  2. 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...

  3. Combinatorics of bicubic maps with hard particles

    Science.gov (United States)

    Bouttier, J.; Di Francesco, P.; Guitter, E.

    2005-05-01

    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.

  4. Machining of hard-to-machine materials

    OpenAIRE

    2016-01-01

    Bakalářská práce se zabývá studiem obrábění těžkoobrobitelných materiálů. V první části jsou rozděleny těžkoobrobitelné materiály a následuje jejich analýza. V další části se práce zaměřuje na problematiku obrobitelnosti jednotlivých slitin. Závěrečná část práce je věnovaná experimentu, jeho statistickému zpracování a nakonec následnému vyhodnocení. This bachelor thesis studies the machining of hard-to-machine materials. The first part of the thesis considers hard-to-machine materials and ...

  5. 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…

  6. 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.

  7. Multidensity integral-equation theory for short diblock hard-sphere-sticky-hard-sphere chains.

    Science.gov (United States)

    Wu, Ning; Chiew, Y C

    2010-04-01

    The multidensity Ornstein-Zernike integral equation theory is applied to study a simple model of hard sphere/sticky hard sphere diblock chains. The multidensity integral equation formalism has been successfully used to model the equilibrium structure and thermodynamic properties of homonuclear chains and shorter dimer fluids; to our knowledge it has not been applied to model diblock chains. In this work, a diblock chain fluids is represented by an m-component equal molar mixture of hard spheres with species 1,2,...,mh and sticky hard spheres with species mh+1,mh+2,...,m. Each spherical particle has two attractive sites A and B except species 1 and m, which have only one site per particle. In the limit of complete association, this mixture yields a system of monodisperse diblock chains. A general solution of this model is obtained in the Percus-Yevick, Polymer Percus-Yevick and ideal chain approximations. Both structural and thermodynamic properties of this model are investigated. From this study, a microphase separation is predicted for relatively short diblock symmetric and asymmetric chains. This microphase separation is enhanced at lower temperature and higher density. When chain length increases, the phase transition changes from a microphase level to a macrophase level. The size of microdomain structure is found to be dependent on total chain length, relative ratio of block lengths, temperature, and density.

  8. 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.

  9. 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.

  10. Radiation Hardness Assurance (RHA) for Space Systems

    Science.gov (United States)

    Poivey, Christian; Buchner, Stephen

    2007-01-01

    This presentation discusses radiation hardness assurance (RHA) for space systems, providing both the programmatic aspects of RHA and the RHA procedure. 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 space radiation environment. RHA also pertains to environment definition, part selection, part testing, spacecraft layout, radiation tolerant design, and mission/system/subsystems requirements. RHA procedure consists of establishing mission requirements, defining and evaluating the radiation hazard, selecting and categorizing the appropriate parts, and evaluating circuit response to hazard. The RHA approach is based on risk management and is confined only to parts, it includes spacecraft layout, system/subsystem/circuit design, and system requirements and system operations. RHA should be taken into account in the early phases of a program including the proposal and feasibility analysis phases.

  11. 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.

  12. Short hard palate in prenatal trisomy 21

    DEFF Research Database (Denmark)

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

    2005-01-01

    and palatine parts) in trisomy 21 fetuses, and to compare the results to normal standards. Design - Material from 31 human fetuses with genetically verified trisomy 21 was studied. The fetuses were derived from legally induced or spontaneous abortions. Palates were, after sectioning, radiographed in lateral...... of the palatal components in trisomy 21 was compared to normal standards. Results - For CRL 150 mm and CRL 170 mm it appears that all three palatal lengths, total length, maxillary length, and palatinal length are significantly shorter in fetuses with trisomy 21. Conclusion - The main conclusion of 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....

  13. 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...

  14. Radiation hardness of the LHCb Outer Tracker

    CERN Document Server

    van Eijk, D; Bauer, T; Färber, C; Bien, A; Coco, V; Deckenhoff, M; Dettori, F; Ekelhof, R; Gersabeck, E; Karbach, T M; Koopman, R; Kozlinskiy, A; Langenbruch, C; Linn, C; Merk, M; Meissner, M; Morawski, P; Pellegrino, A; Serra, N; Seyfert, P; Spaan, B; Swientek, S; Storaci, B; Tuning, N; Szczekowski, M; Uwer, U; Visser, E; Wiedner, D; Witek, M

    2012-01-01

    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.

  15. Induction surface hardening of hard coated steels

    DEFF Research Database (Denmark)

    Pantleon, Karen; Kessler, Olaf; Hoffmann, Franz

    1999-01-01

    -process is the high deposition temperature, consequently the properties of steel substrates are negatively influenced. Therefore, a subsequent heat treatment of the coated steels is necessary to restore the properties of steels ready for operation. Induction surface hardening is used as a method of heat treatment....... The effect of induction surface hardening on the properties of the coating-substrate-systems is mainly characterized using investigations of microstructure and chemical composition as well as measurements of hardness and residual stresses in dependence on the distance from the surface. Furthermore......, the scratch test is used to estimate critical loads for cohesive and adhesive failure of the coatings. Additionally, distortion measurements are carried out. The results emphasize the advantage of induction surface hardening as a method of subsequent heat treatment of CVD-coated steels....

  16. 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

  17. Shock compression synthesis of hard materials

    Energy Technology Data Exchange (ETDEWEB)

    Willson, C.G. [Univ. of Texas, Austin, TX (United States). Dept. of Chemistry

    1999-03-01

    The purpose of this research was to adapt the high explosives technology that was developed in conjunction with nuclear weapons programs to subjecting materials to ultra-high pressures and to explore the utility of this technique for the synthesis of hard materials. The research was conducted in collaboration with researchers at the University of Texas, Texas Tech University and Pantex (Mason and Hanger Corp.). The group designed, modeled, built, and tested a new device that allows quantitative recovery of grams of material that have been subjected to unprecedented pressures. The modeling work was done at Texas Tech and Pantex. The metal parts and material samples were made at the University of Texas, and Pantex machined the explosives, assembled the devices and conducted the detonations. Sample characterization was carried out at the University of Texas and Texas Tech.

  18. Hard diffraction in the QCD dipole picture

    CERN Document Server

    Bialas, A

    1995-01-01

    Using the QCD dipole picture of the BFKL pomeron, the gluon contribution to the cross-section for single diffractive dissociation in deep-inelastic high-energy scattering is calculated. The resulting contribution to the proton diffractive structure function integrated over t is given in terms of relevant variables, x_{\\cal P}, Q^2, and \\beta = x_{Bj}/x_{\\cal P}. It factorizes into an explicit x_{\\cal P}-dependent Hard Pomeron flux factor and structure function. The flux factor is found to have substantial logarithmic corrections which may account for the recent measurements of the Pomeron intercept in this process. The triple Pomeron coupling is shown to be strongly enhanced by the resummation of leading logs. The obtained pattern of scaling violation at small \\beta is similar to that for F_2 at small x_{Bj}.

  19. The Glasma and the Hard Ridge

    CERN Document Server

    Moschelli, George

    2009-01-01

    Correlation measurements indicate that excess two particle correlations extend over causally disconnected rapidity ranges. Although, this enhancement is broad in relative rapidity $\\eta=\\eta_1 - \\eta_2$, it is focused in a narrow region in relative azimuthal angle $\\phi=\\phi_1 - \\phi_2$. The resulting structure looks like a ridge centered at $\\eta = \\phi=0$. Similar ridge structures are observed in correlations of particles associated with a jet trigger (the hard ridge) and in correlations without a trigger (the soft ridge). The long range rapidity behavior requires that the correlation originates in the earliest stage of the collision, and probes properties of the production mechanism. Glasma initial conditions as predicted by the theory of Color Glass Condensate and provide a and early stage correlation that naturally extends far in rapidity. We have previously shown that the soft ridge is a consequence of particles forming from an initial Glasma phase that experience a later stage transverse flow. We exten...

  20. Hard implant coatings with antimicrobial properties.

    Science.gov (United States)

    Moseke, Claus; Gbureck, Uwe; Elter, Patrick; Drechsler, Peter; Zoll, Andreas; Thull, Roger; Ewald, Andrea

    2011-12-01

    Infection of orthopaedic implants often leads to inflammation immediately after surgery and increases patient morbidity due to repetitive operations. Silver ions have been shown to combine good biocompatibility with a low risk of inducing bacterial resistance. In this study a physical vapour deposition system using both arc deposition and magnetron sputtering has been utilized to produce silver ion doped TiN coatings on Ti substrates. This biphasic system combines the advantages of silver induced bactericidity with the good mechanical properties of TiN. Crystallographic analysis by X-ray diffraction showed that silver was deposited as well in its elementary form as it was incorporated into the crystal lattice of TiN, which resulted in increasing hardness of the TiN-coatings. Elution experiments revealed a continuous release of Ag ions in phosphate buffered saline. The coatings showed significant inhibitory effects on the growth of Staphylococcus epidermidis and Staphylococcus aureus and practically no cell-toxicity in cytocompatibility tests.

  1. 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...

  2. Effect of wall hardness on hemolysis.

    Science.gov (United States)

    Yasuda, T; Shimokasa, K; Funakubo, A; Fukui, Y

    2000-08-01

    One of the major problems for artificial organs to develop and to improve is the reduction of hemolysis. The optimum designing of less hemolysis artificial organs is achieved through computational analysis and flow visualization techniques. However, it is impossible to know the quantitative relation between hemolysis and these analytic data. Thus, in vitro studies were performed to estimate these devices on hemolysis because there is no standard for designing these devices with less hemolysis. Therefore, it is essential to reveal the relation between blood flow behaviors and hemolysis. Previous studies reported that hemolysis was caused by a combination of physical factors. In particular, shear stress, pressure, and other fluid dynamical effects were shown to induce hemolysis. In another fluid dynamical experiment reported, the collision flow against the sanded wall was considered the most important factor that directly effected blood damage, which led to hemolysis. The blood flow impact of the collision against the wall effected serious damage to red blood cells. The objective of this study was to point out the relationship between physical force (pressure) in collision flow and hemolysis. In vitro tests using bovine blood and a circulation model that included a jet flow that collides against a wall were conducted. In these tests, we changed the material of the wall by replacing silicone rubber of various thicknesses. The thickness of the silicone rubber is inversely proportional to its hardness. The results show that the increasing rate of hemolysis was lower when the surface was coated by silicone rubber. In conclusion, we considered that it is possible to reduce hemolysis by adjusting the hardness of the material and contacted blood flow.

  3. 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.

  4. Germanium content in Polish hard coals

    Directory of Open Access Journals (Sweden)

    Makowska Dorota

    2016-01-01

    Full Text Available Due to the policy of the European Union, it is necessary to search for new sources of scarce raw materials. One of these materials is germanium, listed as a critical element. This semi-metal is widely used in the electronics industry, for example in the production of semiconductors, fibre optics and solar cells. Coal and fly ash from its combustion and gasification for a long time have been considered as a potential source of many critical elements, particularly germanium. The paper presents the results of germanium content determination in the Polish hard coal. 23 coal samples of various coal ranks were analysed. The samples were collected from 15 mines of the Upper Silesian Coal Basin and from one mine of the Lublin Coal Basin. The determination of germanium content was performed with the use of Atomic Absorption Spectrometry with Electrothermal Atomization (GFAAS. The investigation showed that germanium content in the analysed samples was at least twice lower than the average content of this element in the hard coals analysed so far and was in the range of 0.08 ÷ 1.28 mg/kg. Moreover, the content of Ge in the ashes from the studied coals does not exceed 15 mg/kg, which is lower than the average value of Ge content in the coal ashes. The highest content of this element characterizes coals of the Lublin Coal Basin and young coals type 31 from the Vistula region. The results indicate a low utility of the analysed coal ashes as a source of the recovery of germanium. On the basis of the analyses, the lack of the relationship between the content of the element and the ash content in the tested coals was noted. For coals of the Upper Silesian Coal Basin, the relationship between the content of germanium in the ashes and the depth of the seam was observed.

  5. 3D Bioprinting Technologies for Hard Tissue and Organ Engineering

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    2016-09-01

    Full Text Available Hard tissues and organs, including the bones, teeth and cartilage, are the most extensively exploited and rapidly developed areas in regenerative medicine field. One prominent character of hard tissues and organs is that their extracellular matrices mineralize to withstand weight and pressure. Over the last two decades, a wide variety of 3D printing technologies have been adapted to hard tissue and organ engineering. These 3D printing technologies have been defined as 3D bioprinting. Especially for hard organ regeneration, a series of new theories, strategies and protocols have been proposed. Some of the technologies have been applied in medical therapies with some successes. Each of the technologies has pros and cons in hard tissue and organ engineering. In this review, we summarize the advantages and disadvantages of the historical available innovative 3D bioprinting technologies for used as special tools for hard tissue and organ engineering.

  6. Effect of Loading Rate Upon Conventional Ceramic Microindentation Hardness

    Science.gov (United States)

    2002-01-01

    silicate crown glass. In this modification of the tradi- tional Vickers hardness test, both load and displacement were monitored during the indentation...loads up to 30 N. Alumina, two aluminum nitrides, and two zirconias had a dynamic hardness from 9 % to 19 % greater than the static hardness at loads up...M. Hooper, Indentation Creep in Zirconia Ceramics Between 290 K and 1073 K, in Mechanics of Creep, Brittle Materials, A. Cooks and A. Ponter, eds

  7. Fusion of Hard and Soft Information in Nonparametric Density Estimation

    Science.gov (United States)

    2015-06-10

    estimation exploiting, in concert, hard and soft information. Although our development, theoretical and numerical, makes no distinction based on sample...Fusion of Hard and Soft Information in Nonparametric Density Estimation∗ Johannes O. Royset Roger J-B Wets Department of Operations Research...univariate density estimation in situations when the sample ( hard information) is supplemented by “soft” information about the random phenomenon. These

  8. 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 ...

  9. Hardness testing of some fissure-sealing materials.

    Science.gov (United States)

    Ulvestad, H

    1977-11-01

    The mechanical properties of fissure-sealing materials are of significant importance for their durability, i.e. their wear resistance. One of the methods of evaluating a material's resistance to attrition is to apply a hardness test. In the present investigation, the surface hardness of some fissure-sealing materials was tested. Sealants made from diluted composite materials and with inclusion of inorganic filler particles appeared to have a considerable higher surface hardness than the other sealing materials tested.

  10. 3D Bioprinting Technologies for Hard Tissue and Organ Engineering

    OpenAIRE

    Xiaohong Wang; Qiang Ao; Xiaohong Tian; Jun Fan; Yujun Wei; Weijian Hou; Hao Tong; Shuling Bai

    2016-01-01

    Hard tissues and organs, including the bones, teeth and cartilage, are the most extensively exploited and rapidly developed areas in regenerative medicine field. One prominent character of hard tissues and organs is that their extracellular matrices mineralize to withstand weight and pressure. Over the last two decades, a wide variety of 3D printing technologies have been adapted to hard tissue and organ engineering. These 3D printing technologies have been defined as 3D bioprinting. Especial...

  11. On the Indeterminacy in Hardness of Shape Memory Alloys

    Institute of Scientific and Technical Information of China (English)

    F.T.Cheng

    2004-01-01

    The present communication addresses an interesting problem related to the indeterminacy in hardness of superelastic NiTi reported by Xu et al.[1]. The origin of the indeterminacy is attributed to the inadequacy of the conventional Vickers hardness testing measurement which does not record elastic deformation, and thus the indeterminacy may be removed with suitable techniques. Concepts of hardness in relation to deformation are clarified. Recommendations for measuring the hardness of NiTi and other elastic-plastic materials are suggested, together with comments on the advantages and disadvantages of each of these methods.

  12. A New method of preparing iso-hardness plots

    Science.gov (United States)

    Kumar, V.; Patwardhan, A. K.

    1993-02-01

    A new approach has been used for the preparation of iso-hardness plots, which are very useful in the heat treating of metals and alloys. An alloy white iron containing ~6% Mn, ~5% Cr, and ~3% Cu was heat treated at 800,850,900,950,1000, and 1050 °C and soaked for 2, 4, 6, 8, and 10 h, respectively, at each of these temperatures followed by air cooling. It was observed that, although the hardness varied linearly with soaking time, its variation with soaking temperature was nonlinear. This can be represented as: H = 98.285e2021.33/T + (0.037 - 0.316 × 10- 4 T) . t where H is Vickers hardness; T is soaking temperature in K; and t is soaking time in seconds. The variation in hardness has been discussed in light of microstructural changes that can take place upon heat treating. A three-dimensional plot of hardness, soaking temperature, and time was prepared based on the above equation. It revealed that the variation in hardness on heat treating can be represented as a surface instead of lines, where the change in the slope of the surface reflects the various transformations occurring in the alloy system. This iso- hardness plot, consisting of contours of constant hardness, has been prepared by projecting the above-mentioned surface on the soaking temperature- time plane. The method of selection of heat treating parameters based on this iso- hardness plot is discussed.

  13. Molecular Thermodynamics of Charged Hard-Dumbbell Fluids

    Institute of Scientific and Technical Information of China (English)

    秦原; 刘洪来; 胡英

    2001-01-01

    Chemical potentials of charged hard-dumbbell fluids are obtained by Monte Carlo simulations using Widom's test-particle method, corresponding compressibility factors are achieved by integration of chemical potentials at different densities. A molecular thermodynamic model is also developed for these charged hard-dumbbell fluids where the residual Helmholtz function is composed of two terms: a reference term responsible for the charged hard spheres and a bonding contribution measuring the sticky interactions between positive and negative hard ions.Model predictions are in good agreement with simulation results.

  14. Flour quality and kernel hardness connection in winter wheat

    Directory of Open Access Journals (Sweden)

    Szabó B. P.

    2016-12-01

    Full Text Available Kernel hardness is controlled by friabilin protein and it depends on the relation between protein matrix and starch granules. Friabilin is present in high concentration in soft grain varieties and in low concentration in hard grain varieties. The high gluten, hard wheat our generally contains about 12.0–13.0% crude protein under Mid-European conditions. The relationship between wheat protein content and kernel texture is usually positive and kernel texture influences the power consumption during milling. Hard-textured wheat grains require more grinding energy than soft-textured grains.

  15. Moisture influence on near-infrared prediction of wheat hardness

    Science.gov (United States)

    Windham, William R.; Gaines, Charles S.; Leffler, Richard G.

    1991-02-01

    Recently near infrared (NTR) reflectance instrumentation has been used to provide an empirical measure of wheat hardness. This hardness scale is based on the radiation scattering properties of meal particles at 1680 and 2230 nm. Hard wheats have a larger mean particles size (PS) after grinding than soft wheats. However wheat kernel moisture content can influence mean PS after grinding. The objective of this study was to determine the sensitivity of MR wheat hardness measurements to moisture content and to make the hardness score independent of moisture by correcting hardness measurements for the actual moisture content of measured samples. Forty wheat cultivars composed of hard red winter hard red spring soft red winter and soft white winter were used. Wheat kernel subsamples were stored at 20 40 60 and 80 relative humidity (RH). After equilibration samples were ground and the meal analyzed for hardness score (HS) and moisture. HS were 48 50 54 and 65 for 20 40 60 and 80 RH respectively. Differences in HS within each wheat class were the result of a moisture induced change in the PS of the meal. An algorithm was developed to correct HS to 11 moisture. This correction provides HS that are nearly independent of moisture content. 1.

  16. 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.

  17. Hard nanocomposite Zr-Y-N coatings, correlation between hardness and structure

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.; Polakova, H. [Univ. of West Bohemia, Plzen (Czech Republic). Dept. of Phys.

    2000-05-01

    The article reports on structure and mechanical properties of Zr-Y-N nanocomposite films containing two immiscible elements (Zr,Y) as metals. Films were prepared by d.c.-reactive magnetron sputtering of alloyed targets ZrY (80/20 at.%) and ZrY (93/7 at.%) in a mixture of Ar+N{sub 2} using round planar unbalanced magnetrons of diameter 100 mm. It was shown that: (i) there is a strong correlation between the structure of the film and its hardness, H; (ii) the film structure can be controlled with the interlayer inserted between the substrate and the Zr-Y-N film; and (iii) the film hardness depends on the ratio N/(Zr+Y) in the film and the crystallographic orientation of ZrN grains. Superhard nanocomposite films with hardness greater than 40 GPa were prepared. These films are characterized by (i) the X-ray reflection from ZrN(200) grains and no reflection from the second phase containing Y; and (ii) the ratio N/(Zr+Y){approx}1. Also, it was found that the incorporation of nitrogen into the pure ZrY alloy film results in dramatic changes of its mechanical properties. The Zr-Y-N film can be very hard (up to 47 GPa), exhibits the high elastic recovery (W{sub e} up to 83%) and the high resistance to plastic deformation [H{sup 3}/E*{sup 2} up to approx. 0.75, where E*=E/(1-{nu}{sup 2}), E is the Young's modulus and {nu} is the Poisson's ratio]. On the contrary, the ZrY alloy film is soft (H{approx}6 GPa) and exhibits a low elastic recovery (W{sub e}=32%). (orig.)

  18. 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

  19. 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

  20. 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.

  1. 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...

  2. Like Beauty, Complexity is Hard to Define

    Science.gov (United States)

    Tsallis, Constantino

    Like beauty, complexity is hard to define and rather easy to identify: nonlinear dynamics, strongly interconnected simple elements, some sort of divisoria aquorum between order and disorder. Before focusing on complexity, let us remember that the theoretical pillars of contemporary physics are mechanics (Newtonian, relativistic, quantum), Maxwell electromagnetism, and (Boltzmann-Gibbs, BG) statistical mechanics - obligatory basic disciplines in any advanced course in physics. The firstprinciple statistical-mechanical approach starts from (microscopic) electro-mechanics and theory of probabilities, and, through a variety of possible mesoscopic descriptions, arrives to (oscopic) thermodynamics. In the middle of this trip, we cross energy and entropy. Energy is related to the possible microscopic configurations of the system, whereas entropy is related to the corresponding probabilities. Therefore, in some sense, entropy represents a concept which, epistemologically speaking, is one step further with regard to energy. The fact that energy is not parameter-independent is very familiar: the kinetic energy of a truck is very different from that of a fly, and the relativistic energy of a fast electron is very different from its classical value, and so on. What about entropy? One hundred and forty years of tradition, and hundreds - we may even say thousands - of impressive theoretical successes of the parameter-free BG entropy have sedimented, in the mind of many scientists, the conviction that it is unique. However, it can be straightforwardly argued that, in general, this is not the case...

  3. Hard X-ray Timing with EXIST

    CERN Document Server

    Grindlay, J E

    2004-01-01

    The Energetic X-ray Timing Survey Telescope (EXIST) mission concept is under study as the Black Hole Finder Probe (BHFP), one of the three Einstein Probe missions in the Beyond Einstein Program in the current NASA Strategic Plan. EXIST would conduct an all-sky imaging hard X-ray ($\\sim$10-600 keV) survey with unprecedented sensitivity: about 5 $\\times 10^{-13}$ cgs over any factor of 2 bandwidth, or comparable to that achieved at soft X-rays in the ROSAT survey. The proposed angular resolution of 5arcmin, temporal resolution of 10microsec, energy resolution of 1-4 keV over the broad band, and duty cycle of 0.2-0.5 for continuous coverage of any source provide an unprecedented phase space for timing and spectral studies of black holes --from stellar to supermassive, as well as neutron stars and accreting white dwarfs. The large sky coverage allows intrinsically rare events to be studied. One particularly exciting example is the possible detection of tidal disruption of stars near quiescent AGN. Super flares fr...

  4. 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 (<200 nm for polymers), and pen to pen variation. With these new arrays, patterns with as many as 5.9 billion features in a 14.5 cm(2) area were written using a four hundred thousand 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.

  5. 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...

  6. 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.

  7. Hardness Analysis. Training Module 5.215.2.77.

    Science.gov (United States)

    Bonte, John L.; Davidson, Arnold C.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with hardness analysis using the EDTA method and the calculation of hardness given metal ion concentrations and a factor table. Included are objectives, an instructor guide, student handouts, and transparency masters. A video tape is also…

  8. Effects of Hard Limits on Bifurcation, Chaos and Stability

    Institute of Scientific and Technical Information of China (English)

    Rui-qi Wang; Ji-cai Huang

    2004-01-01

    An SMIB model in the power systems,especially that concering the effects of hard limits on bifurcations, chaos and stability is studied.Parameter conditions for bifurcations and chaos in the absence of hard limits are compared with those in the presence of hard limits.It has been proved that hard limits can affect system stability.We find that (1)hard limits can change unstable equilibrium into stable one;(2)hard limits can change stability of limit cycles induced by Hopf bifurcation;(3)persistence of hard limits can stabilize divergent trajectory to a stable equilibrium or limit cycle;(4)Hopf bifurcation occurs before SN bifurcation,so the system collapse can be controlled before Hopf bifurcation occurs.We also find that suitable limiting values of hard limits can enlarge the feasibility region.These results are based on theoretical analysis and numerical simulations, such as condition for SNB and Hopf bifurcation,bifurcation diagram,trajectories,Lyapunov exponent,Floquet multipliers,dimension of attractor and so on.

  9. 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.

  10. Pricing of convertible bonds with hard call features

    NARCIS (Netherlands)

    Wever, Jolle O.; Smid, Peter P.M.; Koning, Ruud H.

    2002-01-01

    This paper discusses the development of a valuation model for convertible bonds with hard call features. We define a hard call feature as the possibility for the issuer to redeem a convertible bond before maturity by paying the call price to the bondholder. We use the binomial approach to model conv

  11. Dough Rheology and Wet Milling of Hard Waxy Wheat Flours

    Science.gov (United States)

    To realize the full potential of waxy wheat (Triticum aestivum L.), wet milling of waxy wheat flour to produce gluten and waxy wheat starch was investigated. Flours of six advanced lines of waxy hard wheats, one normal hard wheat (‘Karl 92’), and one partial waxy wheat (‘Trego’) were fractionated by...

  12. 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 ...

  13. Direct measurement of thermodynamic properties of colloidal hard spheres

    NARCIS (Netherlands)

    Dullens, R.P.A.; Kegel, W.K.; Aarts, D.G.A.L.

    2008-01-01

    Recently, we have shown how to measure thermodynamic properties of colloidal hard sphere suspensions by microscopy [Dullens et al. (2006) PNAS 103, 529]. Here, we give full experimental details on how to acquire three dimensional snapshots of a colloidal hard sphere suspension over a wide range of d

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    In the auxiliary input model an adversary is allowed to see a computationally hard-to-invert function of the secret key. The auxiliary input model weakens the bounded leakage assumption commonly made in leakage resilient cryptography as the hard-to-invert function may information-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...

  15. 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.

  16. 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

  17. 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.

  18. Hard magnetism in structurally engineered silica nanocomposite.

    Science.gov (United States)

    Song, Hyon-Min; Zink, Jeffrey I

    2016-09-21

    Creation of structural complexity by simple experimental control will be an attractive approach for the preparation of nanomaterials, as a classical bottom-up method is supplemented by a more efficient and more direct artificial engineering method. In this study, structural manipulation of MCM-41 type mesoporous silica is investigated by generating and imbedding hard magnetic CoFe2O4 nanoparticles into mesoporous silica. Depending on the heating rate and target temperature, mesoporous silica undergoes a transformation in shape to form hollow silica, framed silica with interior voids, or melted silica with intact mesostructures. Magnetism is governed by the major CoFe2O4 phase, and it is affected by antiferromagnetic hematite (α-Fe2O3) and olivine-type cobalt silicate (Co2SiO4), as seen in its paramagnetic behavior at the annealing temperature of 430 °C. The early formation of Co2SiO4 than what is usually observed implies the effect of the partial substitution of Fe in the sites of Co. Under slow heating (2.5 °C min(-1)) mesostructures are preserved, but with significantly smaller mesopores (d100 = 1.5 nm). In addition, nonstoichiometric CoxFe1-xO with metal vacancies at 600 °C, and spinel Co3O4 at 700 °C accompany major CoFe2O4. The amorphous nature of silica matrix is thought to contribute significantly to these structurally diverse and rich phases, enabled by off-stoichiometry between Si and O, and accelerated by the diffusion of metal cations into SiO4 polyhedra at an elevated temperature.

  19. Parents welcome "hard-hitting" campaign.

    Science.gov (United States)

    1994-01-01

    The FPA (Family Planning Association)'s recent pilot campaign to encourage parents to talk to their children about sex has generated an excellent response rate. Funded by the Department of Health as part of "The health of the nation" efforts to reduce unplanned teenage pregnancies, the campaign centered on two radio advertisements. Aired during March in Greater London and North West England, the advertisements featured a free phone number from which people could obtain free copies of the booklet "Answering your child's questions," part of the FPA's "Growing Up" series. Nearly 7500 copies of the booklet were distributed in response to over 5000 requests--2500 rang in the first week alone. Most requests were from parents (69% mothers, 31% fathers) with one to three children aged between 7 and 13. Over 1000 requests were from parents with children under 7. Hundreds of schools, youth clubs, health professionals and voluntary organizations requested multiple booklets for use in their work. Research carried out to gauge public reaction showed overwhelming support for the campaign's message, demonstrating the immense need by parents for information in this area. "Answering your child's questions" was praised for being "open, direct and easy to follow." One parent said, "The booklet arms parents with the right way of putting information across." Parents described the advertisements as "hard-hitting" and "attention-grabbing." One listener commented: "They really stopped me in my tracks." FPA director Doreen Massey said: "The favorable reaction to the campaign is extremely encouraging. We are looking at ways to relay this pilot effort into a full-scale UK-wide campaign next year."

  20. 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...

  1. The uptake of water hardness metals by human hair.

    Science.gov (United States)

    Evans, A O; Marsh, J M; Wickett, R R

    2011-01-01

    The objective of this work was to examine the variables that influence the interaction between water hardness metals and human hair. Hair extracts various constituents from the tap water used during daily hygiene practices and chemical treatments. Calcium and magnesium metal ions are the most prevalent and give water "hardness." Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was employed to quantify the metal content of hair, which was studied as a function of the following variables: hair condition (oxidative damage), level of water hardness, and water pH. We have demonstrated that these variables impact water hardness metal uptake to varying extents, and the effects are driven primarily by the binding capacity (available anionic sites) of the hair. The condition of the hair, a key representation of the binding capacity, was most influential. Interestingly, water hardness levels had only a small effect on uptake; hair became saturated with notable amounts of water hardness metals even after repeated exposure to soft water. Water pH influenced metal uptake since side chains of hair proteins deprotonate with increasing alkalinity. These insights highlight the importance to the hair care industry of understanding the interaction between water hardness metals and hair.

  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. 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.

  4. Hard water softening effect of a baby cleanser

    Directory of Open Access Journals (Sweden)

    Walters RM

    2016-10-01

    Full Text Available Russel M Walters, Emmanuel Anim-Danso, Stephanie M Amato, Kimberly A Capone, M Catherine Mack, Lorena S Telofski, David A Mays Skin Care Research & Development, Johnson & Johnson Consumer Inc., Skillman, NJ, USA Background: Hard water is associated with atopic dermatitis (eczema. We wanted to determine if a baby cleanser and its individual components altered free ionized calcium (Ca2+ in a simulated hard water baby bath. For these studies, an in vitro determination of free Ca2+ in a simulated hard water baby bath, and an in vivo exploratory study of free Ca2+ absorption into skin from hard water were performed.Methods: Free Ca2+ was measured with an ion-sensitive electrode in vitro in hard water (100–500 ppm, Ca2+ before and after addition of the cleanser and/or its components. In an exploratory study, absorption of Ca2+ into skin from hard water was determined in three female participants (aged 21–29 years.Results: At an in-use dilution of 1%, the test cleanser reduced free Ca2+ from ~500 ppm to <200 ppm; a 10% in-use dilution bound virtually all free Ca2+. The anionic surfactant component contributed the most to this effect. In the exploratory in vivo study, we measured a reduction of ~15% in free Ca2+ from simulated hard water over 10 minutes.Conclusion: Baby cleansers can bind free Ca2+ and reduce the effective water hardness of bath water. Reducing the amount of free Ca2+ in the water will reduce the availability of the ion for binding to the skin. Altering or reducing free Ca2+ concentrations in bath water may be an important parameter in creating the ideal baby bath. Keywords: bath, cleanser, hard water, infant, neonate, surfactant

  5. Rotation of hard particles in a soft matrix

    Science.gov (United States)

    Yang, Weizhu; Liu, Qingchang; Yue, Zhufeng; Li, Xiaodong; Xu, Baoxing

    Soft-hard materials integration is ubiquitous in biological materials and structures in nature and has also attracted growing attention in the bio-inspired design of advanced functional materials, structures and devices. Due to the distinct difference in their mechanical properties, the rotation of hard phases in soft matrixes upon deformation has been acknowledged, yet is lack of theory in mechanics. In this work, we propose a theoretical mechanics framework that can describe the rotation of hard particles in a soft matrix. The rotation of multiple arbitrarily shaped, located and oriented particles with perfectly bonded interfaces in an elastic soft matrix subjected to a far-field tensile loading is established and analytical solutions are derived by using complex potentials and conformal mapping methods. Strong couplings and competitions of the rotation of hard particles among each other are discussed by investigating numbers, relative locations and orientations of particles in the matrix at different loading directions. Extensive finite element analyses are performed to validate theoretical solutions and good agreement of both rotation and stress field between them are achieved. Possible extensions of the present theory to non-rigid particles, viscoelastic matrix and imperfect bonding are also discussed. Finally, by taking advantage of the rotation of hard particles, we exemplify an application in a conceptual design of soft-hard material integrated phononic crystal and demonstrate that phononic band gaps can be successfully tuned with a high accuracy through the mechanical tension-induced rotation of hard particles. The present theory established herein is expected to be of immediate interests to the design of soft-hard materials integration based functional materials, structures and devices with tunable performance via mechanical rotation of hard phases.

  6. Complexometric assay for water hardness: an interactive lab experiment.

    OpenAIRE

    Milla González, Miguel

    2011-01-01

    Water hardness is due to the presence of multivalent metal ions. In natural waters, the most abundant ions are calcium(II) and, in less amount, magnesium(II). Cations such as Fe(III), Al(III), Mn(II) and other metal ions also contribute to hardness, although their concentration level is much below the concentration level of calcium. Water hardness is a parameter of interest in water analysis, since it has adverse consequences in a great deal of human activities related to the use of this natu...

  7. 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.

  8. Directions of changes of hard coal output technologies in Poland

    Institute of Scientific and Technical Information of China (English)

    Turek Marian

    2011-01-01

    The author presents the results being the effect of the analysis of innovative rate of individual technologies applied in opening up, development and extraction works which was carried out within the project: "scenarios of technological development of hard coal extractive industry". After presentation of opening up, development and extraction technologies that are applied in Polish hard coal industry and their classification with regard to innovation degree the author describes those technologies in a detailed manner. He brings attention to the most effective systems for hard coal deposits' opening up, development and their extraction, including the extraction of the residual coal. The attention is also paid to the safety level of the applied technologies.

  9. Hard jet probes in terms of colorless QCD dipoles

    CERN Document Server

    Peschanski, R

    2000-01-01

    the forward jet playing the role of a hard probe is analyzed in terms of QCD dipole (color-singlet q\\bar q) configurations in the transverse position space. There are sizable differences with the analogous q\\bar q configurations of a hard photon which may lead to significant phenomenological consequences on the analysis of hard processes using a forward jet probe, e.g. at the Tevatron. A geometrical interpretation of the resulting distribution in terms of black disk diffraction is proposed.

  10. Self-diffusion in liquid gallium and hard sphere model

    Directory of Open Access Journals (Sweden)

    Blagoveshchenskii Nikolay

    2015-01-01

    Full Text Available Incoherent and coherent components of quasielastic neutron scattering have been studied in the temperature range of T = 313 K – 793 K aiming to explore the applicability limits of the hard-sphere approach for the microscopic dynamics of liquid gallium, which is usually considered as a non-hard-sphere system. It was found that the non-hard-sphere effects come into play at the distances shorter than the average interatomic distance. The longer range diffusive dynamics of liquid Ga is dominated by the repulsive forces between the atoms.

  11. Investigation of sequential cryogenic hard turning and ball burnishing processes

    Directory of Open Access Journals (Sweden)

    K. Żak

    2014-10-01

    Full Text Available This paper presents a sequential machining process which incorporates CBN hard turning with cryogenic pre-cooling of the workpiece (CHT and ball burnishing (BB. The main goal of this study was to select machining conditions enhancing the quality of parts machined by hard turning including the surface roughness Ra of about 0,2 μm, good bearing properties and reducing the white layer. Changes of surface roughness, surface texture, microstructure alterations and micro-hardness distribution are discusses.

  12. 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.

  13. Status of hard interactions (jets and heavy flavor)

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2001-06-01

    We review the status of hard interactions, in particular of jet and heavy flavor production, at HERA and LEP. Emphasis is given to recent theoretical developments. Instantons, event shapes, and prompt photons are also briefly discussed. (orig.)

  14. 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...

  15. 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.

  16. 21 CFR 133.148 - Hard grating cheeses.

    Science.gov (United States)

    2010-04-01

    ... than 32 percent of milkfat, as determined by the methods prescribed in § 133.5 (a), (b), and (d). Hard... harmless preparation of enzymes of animal or plant origin capable of aiding in the curing or development...

  17. New Biologic Drug Tackles Hard-To-Control Asthma

    Science.gov (United States)

    ... html New Biologic Drug Tackles Hard-to-Control Asthma Benralizumab significantly cuts respiratory attacks, two trials show ... drug reduces flare-ups in patients with severe asthma that is not controlled by steroid inhalers alone, ...

  18. 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...

  19. 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.

  20. 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...

  1. 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.

  2. 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...

  3. 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...

  4. 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...

  5. 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

  6. 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

  7. 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

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

    Science.gov (United States)

    Chakraborty, Riya; De, Moumita; Roy, Sudakshina; Dey, Arjun; Biswas, Sampad K.; Middya, Tapas Ranjan; Mukhopadhyay, Anoop K.

    2012-06-01

    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.

  9. Simple Wriggling is Hard unless You Are a Fat Hippo

    CERN Document Server

    Kostitsyna, Irina

    2010-01-01

    We prove that it is NP-hard to decide whether two points in a polygonal domain with holes can be connected by a wire. This implies that finding any approximation to the shortest path for a long snake amidst polygonal obstacles is NP-hard. On the positive side, we show that snake's problem is "length-tractable": if the snake is "fat", i.e., its length/width ratio is small, the shortest path can be computed in polynomial time.

  10. Extremely long hard bursts observed by Konus-Wind

    CERN Document Server

    Pal'shin, V; Frederiks, D; Golenetskii, S; Il'Inskii, V; Mazets, E; Yamaoka, K; Ohno, M; Hurley, K; Sakamoto, T; Oleynik, P; Ulanov, M; Mitrofanov, I G; Golovin, D; Litvak, M L; Sanin, A B; Boynton, W; Fellows, C; Harshman, K; Shinohara, C; Starr, R; 10.1063/1.2943422

    2013-01-01

    We report the observations of the prompt emission of the extremely long hard burst, GRB 060814B, discovered by Konus-Wind and localized by the IPN. The observations reveal a smooth, hard, ~40-min long pulse followed by weaker emission seen several hours after the burst onset. We also present the Konus-Wind data on similar burst, GRB 971208, localized by BATSE/IPN. And finally we discuss the different possible origins of these unusual events.

  11. Hard water softening effect of a baby cleanser

    Science.gov (United States)

    Walters, Russel M; Anim-Danso, Emmanuel; Amato, Stephanie M; Capone, Kimberly A; Mack, M Catherine; Telofski, Lorena S; Mays, David A

    2016-01-01

    Background Hard water is associated with atopic dermatitis (eczema). We wanted to determine if a baby cleanser and its individual components altered free ionized calcium (Ca2+) in a simulated hard water baby bath. For these studies, an in vitro determination of free Ca2+ in a simulated hard water baby bath, and an in vivo exploratory study of free Ca2+ absorption into skin from hard water were performed. Methods Free Ca2+ was measured with an ion-sensitive electrode in vitro in hard water (100–500 ppm, Ca2+) before and after addition of the cleanser and/or its components. In an exploratory study, absorption of Ca2+ into skin from hard water was determined in three female participants (aged 21–29 years). Results At an in-use dilution of 1%, the test cleanser reduced free Ca2+ from ~500 ppm to <200 ppm; a 10% in-use dilution bound virtually all free Ca2+. The anionic surfactant component contributed the most to this effect. In the exploratory in vivo study, we measured a reduction of ~15% in free Ca2+ from simulated hard water over 10 minutes. Conclusion Baby cleansers can bind free Ca2+ and reduce the effective water hardness of bath water. Reducing the amount of free Ca2+ in the water will reduce the availability of the ion for binding to the skin. Altering or reducing free Ca2+ concentrations in bath water may be an important parameter in creating the ideal baby bath. PMID:27789967

  12. 77 FR 8284 - Western Digital Technologies, Inc., Hard Drive Development Engineering Group Irvine (Formerly at...

    Science.gov (United States)

    2012-02-14

    ... workers of Western Digital Technologies, Inc., Hard Drive Development Engineering Group, Lake Forest... Western Digital Technologies, Inc., Hard Drive Development Engineering Group, Irvine (formerly at Lake... Employment and Training Administration Western Digital Technologies, Inc., Hard Drive Development...

  13. 76 FR 61746 - Western Digital Technologies, Inc.: Hard Drive Development Engineering Group Irvine (Formerly at...

    Science.gov (United States)

    2011-10-05

    ... Western Digital Technologies, Inc., Hard Drive Development Engineering Group, Lake Forest, California... workers and former workers of Western Digital Technologies, Inc., Hard Drive Development Engineering Group... Employment and Training Administration Western Digital Technologies, Inc.: Hard Drive Development...

  14. Equation of state for classical hard-particlelike fluids

    Science.gov (United States)

    Edgal, U. F.; Boukahil, A.; Huber, D. L.

    1995-09-01

    We extend earlier studies of the equation of state of classical hard-particle fluids to potentials where there is an attractive tail in addition to a repulsive hard core. Like the earlier work, the approach is based on the arbitrary point, nearest-neighbor probability density function. In the high temperature (hard-particle) limit, a parametrization of the integrated distribution is introduced. By matching the parameters against the coefficients in a seven-term virial expansion, we obtain an equation of state that is in excellent agreement with the results from Monte Carlo, molecular dynamics calculations in both two and three dimensions. The theory is extended to finite temperatures by treating deviations from the hard-particle limit as small corrections that can be evaluated using hard-particle distribution functions. A comparison is made with the results from a five-term finite temperature virial expansion for a three-dimensional hard-particle system with a square well attractive potential.

  15. Mongoose: Creation of a Rad-Hard MIPS R3000

    Science.gov (United States)

    Lincoln, Dan; Smith, Brian

    1993-01-01

    This paper describes the development of a 32 Bit, full MIPS R3000 code-compatible Rad-Hard CPU, code named Mongoose. Mongoose progressed from contract award, through the design cycle, to operational silicon in 12 months to meet a space mission for NASA. The goal was the creation of a fully static device capable of operation to the maximum Mil-883 derated speed, worst-case post-rad exposure with full operational integrity. This included consideration of features for functional enhancements relating to mission compatibility and removal of commercial practices not supported by Rad-Hard technology. 'Mongoose' developed from an evolution of LSI Logic's MIPS-I embedded processor, LR33000, code named Cobra, to its Rad-Hard 'equivalent', Mongoose. The term 'equivalent' is used to infer that the core of the processor is functionally identical, allowing the same use and optimizations of the MIPS-I Instruction Set software tool suite for compilation, software program trace, etc. This activity was started in September of 1991 under a contract from NASA-Goddard Space Flight Center (GSFC)-Flight Data Systems. The approach affected a teaming of NASA-GSFC for program development, LSI Logic for system and ASIC design coupled with the Rad-Hard process technology, and Harris (GASD) for Rad-Hard microprocessor design expertise. The program culminated with the generation of Rad-Hard Mongoose prototypes one year later.

  16. 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

  17. 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

  18. 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

  19. 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

  20. Turning conditions of Ck 45 steel with alternate hardness zones

    Directory of Open Access Journals (Sweden)

    A. Stoić

    2009-05-01

    Full Text Available Purpose: of this paper is investigation of dynamic impacts on cutting edge during machining of locally hardened steel. Alteration of hardness on a single work piece is a source of impact on tool, which could lead to breakage of cutting tool and work piece surface damage in turning. Influence of material properties (primary hardness is important when work piece is hardened locally by induction and part of material is soft annealed.Design/methodology/approach: Experimental tests of cutting outputs have been done on specimens after induction hardening to evaluate the rate of variation of cutting forces, surface roughness and chip formation because of hardness alteration. Measured data of main cutting force were analyzed in frequency and time domain.Findings: It was found that chip formation condition, chip thickness and chip shape depends on cutting forces alteration in transition areas in the range of 10 to 15%. Much higher alteration of force signal is recorded when machining is performed with low depth of cutting value as a result of backlash in system. The most important value of cutting force correlates with depth of cutting, and roughness correlates oppositely to the hardness.Research limitations/implications: Results and findings presented in this paper are qualitative and might be slightly different in other cutting condition (e.g. other heat treatable steels or other hardening techniques or other single cutting point processes. There is evident force value alteration in the transition (hard to soft state zone.Practical implications: Surface roughness is a consequence of both cutting impacts and of tool/work piece loading condition.Originality/value: Originality of the paper is in analysis for stability of turning to heat treatable steel influenced with alternating work piece hardness. It was recorded edge loading shock overcome from hard to soft machining. It was recorded and analyzed self-exited vibration. A new type of chips: horseshoe

  1. Hardness of FeB4: density functional theory investigation.

    Science.gov (United States)

    Zhang, Miao; Lu, Mingchun; Du, Yonghui; Gao, Lili; Lu, Cheng; Liu, Hanyu

    2014-05-07

    A recent experimental study reported the successful synthesis of an orthorhombic FeB4 with a high hardness of 62(5) GPa [H. Gou et al., Phys. Rev. Lett. 111, 157002 (2013)], which has reignited extensive interests on whether transition-metal borides compounds will become superhard materials. However, it is contradicted with some theoretical studies suggesting transition-metal boron compounds are unlikely to become superhard materials. Here, we examined structural and electronic properties of FeB4 using density functional theory. The electronic calculations show the good metallicity and covalent Fe-B bonding. Meanwhile, we extensively investigated stress-strain relations of FeB4 under various tensile and shear loading directions. The calculated weakest tensile and shear stresses are 40 GPa and 25 GPa, respectively. Further simulations (e.g., electron localization function and bond length along the weakest loading direction) on FeB4 show the weak Fe-B bonding is responsible for this low hardness. Moreover, these results are consistent with the value of Vickers hardness (11.7-32.3 GPa) by employing different empirical hardness models and below the superhardness threshold of 40 GPa. Our current results suggest FeB4 is a hard material and unlikely to become superhard (>40 GPa).

  2. Hard photodisintegration of 3He into a p d pair

    Science.gov (United States)

    Maheswari, Dhiraj; Sargsian, Misak M.

    2017-02-01

    The recent measurements of high energy photodisintegration of a 3He nucleus to a p d pair at 90∘ center of mass demonstrated an energy scaling consistent with the quark counting rule with an unprecedentedly large exponent of s-17. To understand the underlying mechanism of this process, we extended the theoretical formalism of the hard rescattering mechanism (HRM) to calculate the γ 3He→p d 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 a 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→p d transition spectral function, the cross section of hard p d →p d scattering, and the effective charge of the quarks being interchanged during the hard rescattering process. The numerical estimates of all these factors resulted in the magnitude of the cross section, which is surprisingly in good agreement with the data.

  3. Standard test method for knoop and vickers hardness of materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers determination of the Knoop and Vickers hardness of materials, the verification of Knoop and Vickers hardness testing machines, and the calibration of standardized Knoop and Vickers test blocks. 1.2 This test method covers Knoop and Vickers hardness tests made utilizing test forces in micro (9.807 × 10-3 to 9.807 N ) ( 1 to 1000 gf ) and macro (>9.807 to 1176.68 N) ( >1 to 120 kgf ) ranges. Note 1—Previous versions of this standard limited test forces to 9.807 N (1 kgf). 1.3 This test method includes all of the requirements to perform macro Vickers hardness tests as previously defined in Test Method E92, Standard Test Method for Vickers Hardness Testing. 1.4 This test method includes an analysis of the possible sources of errors that can occur during Knoop and Vickers testing and how these factors affect the accuracy, repeatability, and reproducibility of test results. Note 2—While Committee E04 is primarily concerned with metals, the test procedures described are applicab...

  4. 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.

  5. 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.

  6. Proceedings of the Tungsten Workshop for Hard Target Weapons Program

    Energy Technology Data Exchange (ETDEWEB)

    Mackiewicz-Ludtka, G.; Hayden, H.W.; Davis, R.M.

    1995-06-01

    The purpose of this meeting was to review and exchange information and provide technical input for improving technologies relevant to the Hard Target Weapons Program. This workshop was attended by representatives from 17 organizations, including 4 Department of Defense (DoD) agencies, 8 industrial companies, and 5 laboratories within DOE. Hard targets are defined as reinforced underground structures that house enemy forces, weapon systems, and support equipment. DOE-ORO and Martin Marietta Energy Systems, Inc. (Energy Systems) have been involved in advanced materials research and development (R&D) for several DOE and DoD programs. These programs are conducted in close collaboration with Eglin AFB, Department of the Army`s Picatinny Arsenal, and other DoD agencies. As part of this ongoing collaboration, Eglin AFB and Oak Ridge National Laboratory planned and conducted this workshop to support the Hard Target Weapons Program. The objectives of this workshop were to (1) review and identify the technology base that exists (primarily due to anti-armor applications) and assess the applicability of this technology to the Hard Target Weapons Program requirements; (2) determine future directions to establish the W materials, processing, and manufacturing technologies suitable for use in fixed, hard target penetrators; and (3) identify and prioritize the potential areas for technical collaboration among the participants.

  7. 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 ...

  8. Chemical potential of a test hard sphere of variable size in a hard-sphere fluid

    CERN Document Server

    Heyes, David M

    2016-01-01

    The Lab\\'ik and Smith Monte Carlo simulation technique to implement the Widom particle insertion method is extended using Molecular Dynamics (MD) instead to calculate numerically the insertion probability, $P_0(\\eta,\\sigma_0)$, of tracer hard-sphere (HS) particles of different diameters, $\\sigma_0$, in a host HS fluid of diameter $\\sigma$ and packing fraction, $\\eta$, up to $0.5$. It is shown analytically that the only polynomial representation of $-\\ln P_0(\\eta,\\sigma_0)$ consistent with the limits $\\sigma_0\\to 0$ and $\\sigma_0\\to\\infty$ has necessarily a cubic form, $c_0(\\eta)+c_1(\\eta)\\sigma_0/\\sigma+c_2(\\eta)(\\sigma_0/\\sigma)^2+c_3(\\eta)(\\sigma_0/\\sigma)^3$. Our MD data for $-\\ln P_0(\\eta,\\sigma_0)$ are fitted to such a cubic polynomial and the functions $c_0(\\eta)$ and $c_1(\\eta)$ are found to be statistically indistinguishable from their exact solution forms. Similarly, $c_2(\\eta)$ and $c_3(\\eta)$ agree very well with the Boubl\\'ik--Mansoori--Carnahan--Starling--Leland and Boubl\\'ik--Carnahan--Starling-...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kawate, T. [Kwasan and Hida Observatory, Kitashirakawa-oiwakecho, Sakyo, Kyoto 606-8502 (Japan); Nishizuka, N. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 229-8510 (Japan); Oi, A. [College of Science, Ibaraki University, Mito, Ibaraki 310-8512 (Japan); Ohyama, M. [Faculty of Education, Shiga University, 2-5-1 Hiratsu, Otsu, Shiga 1-1, Baba Hikone city, Siga 522-8522 (Japan); Nakajima, H., E-mail: kawate@kusastro.kyoto-u.ac.jp [Nobeyama Solar Radio Observatory, NAOJ, Nobeyama, Minamisaku, Nagano 384-1305 (Japan)

    2012-03-10

    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.

  10. Chemical potential of a test hard sphere of variable size in a hard-sphere fluid

    Science.gov (United States)

    Heyes, David M.; Santos, Andrés

    2016-12-01

    The Labík and Smith Monte Carlo simulation technique to implement the Widom particle insertion method is applied using Molecular Dynamics (MD) instead to calculate numerically the insertion probability, P0(η ,σ0) , of tracer hard-sphere (HS) particles of different diameters, σ0, in a host HS fluid of diameter σ and packing fraction, η , up to 0.5. It is shown analytically that the only polynomial representation of -ln ⁡P0 (η ,σ0) consistent with the limits σ0→0 and σ0→∞ has necessarily a cubic form, c0(η ) +c1(η ) σ0 /σ +c2(η ) (σ0/σ ) 2 +c3(η ) (σ0/σ ) 3 . Our MD data for -ln ⁡P0 (η ,σ0) are fitted to such a cubic polynomial and the functions c0(η ) and c1(η ) are found to be statistically indistinguishable from their exact solution forms. Similarly, c2(η ) and c3(η ) agree very well with the Boublík-Mansoori-Carnahan-Starling-Leland and Boublík-Carnahan-Starling-Kolafa formulas. The cubic polynomial is extrapolated (high density) or interpolated (low density) to obtain the chemical potential of the host fluid, or σ0→σ , as β μex =c0+c1+c2+c3 . Excellent agreement between the Carnahan-Starling and Carnahan-Starling-Kolafa theories with our MD data is evident.

  11. Ice cream structural elements that affect melting rate and hardness.

    Science.gov (United States)

    Muse, M R; Hartel, R W

    2004-01-01

    Statistical models were developed to reveal which structural elements of ice cream affect melting rate and hardness. Ice creams were frozen in a batch freezer with three types of sweetener, three levels of the emulsifier polysorbate 80, and two different draw temperatures to produce ice creams with a range of microstructures. Ice cream mixes were analyzed for viscosity, and finished ice creams were analyzed for air cell and ice crystal size, overrun, and fat destabilization. The ice phase volume of each ice cream were calculated based on the freezing point of the mix. Melting rate and hardness of each hardened ice cream was measured and correlated with the structural attributes by using analysis of variance and multiple linear regression. Fat destabilization, ice crystal size, and the consistency coefficient of the mix were found to affect the melting rate of ice cream, whereas hardness was influenced by ice phase volume, ice crystal size, overrun, fat destabilization, and the rheological properties of the mix.

  12. Charpy Impact Energy and Microindentation Hardness of 60-NITINOL

    Science.gov (United States)

    Stanford, Malcolm K.

    2012-01-01

    60-NITINOL (60 wt.% Ni 40 wt.% Ti) is being studied as a material for advanced aerospace components. The Charpy impact energy and microindentation hardness has been studied for this material, fabricated by vacuum induction skull melting (casting) and by hot isostatic pressing. Test specimens were prepared in various hardened and annealed heat treatment conditions. The average impact energy ranged from 0.33 to 0.49J for the hardened specimens while the annealed specimens had impact energies ranging from 0.89 to 1.18J. The average hardness values of the hardened specimens ranged from 590 to 676 HV while that of the annealed specimens ranged from 298 to 366 HV, suggesting an inverse relationship between impact energy and hardness. These results are expected to provide guidance in the selection of heat treatment processes for the design of mechanical components.

  13. Spacetime Holism and the Hard Problem of Consciousness

    Science.gov (United States)

    Winkler, Franz-Günter

    2006-06-01

    We suppose that the reason for the obvious hardness of the so-called hard problem of consciousness lies in two implicit assumptions characteristic of western thinking. The assumption of the fundamental existence of the object and the assumption of the fundamental existence of the self cannot both be valid, if something like a psychophysical link is taken for granted. Other than monistic approaches that are incompatible with one of the two assumptions, we strictly reject both assumptions. Spacetime holism, which in the first place is a view of the material world, can be extended by an assumption on the nature of consciousness, thus providing the basis for a non-reductive solution to the hard problem of consciousness.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, J.M.; Cheeks, L.; Green, K. (Medical College of Georgia, Augusta (USA))

    1990-02-01

    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.

  15. Hard X-ray micro-focusing beamline at SSRF

    Institute of Scientific and Technical Information of China (English)

    张丽丽; 兰旭颖; 毛成文; 王娟; 蒋晖; 郑怡; 董朝晖; 曾乐勇; 李爱国; 闫帅; 蒋升; 杨科; 王华; 何上明; 梁东旭; 张玲; 何燕

    2015-01-01

    The hard X-ray micro-focusing beamline (BL15U1) of SSRF is dedicated to hard X-ray micro/nano-spectrochemical analysis consisting of X-ray fluorescence (XRF), X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques. It is one of the most versatile instruments in hard X-ray microscopy sci-ence. Since its commission in 2009, BL15U1 has allocated over 25000 h beamtime for users, and about 700 proposals have been executed. The beamline and the experimental end-station were upgraded for several times to facilitate the users’ experimental needs and make it more convenient to operate. In this paper, we give a review on the beamline, describing its characteristics, recent technical developments, and a few examples of scientific progresses achieved in recent years on BL15U1.

  16. 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...

  17. 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.

  18. 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.

  19. Surface Integrity in Turning of Annealed Brass: Hardness Prediction

    Science.gov (United States)

    Zurita, O.; Di Graci, V.

    2012-07-01

    The purpose of this study was to obtain a comprehensive understanding of the effects of cutting parameters (depth of cut, feed rate, and cutting speed) on the surface integrity of, in terms of superficial hardening, annealed brass during a turning process. The results indicate that no significant phase transformations occurred for any of the turning conditions evaluated; however, microstructural changes were observed, as well as changes in the superficial hardness were measured. It was found that when the studied cutting parameters increase, the superficial hardness increases, with the cutting speed having less influence (2.56%), and feed rate having the greatest effect (22.67%). Finally, a mathematical expression is proposed, which relates the cutting parameters to the maximum hardness obtained for a given cutting condition.

  20. Fundamental measure theory for hard-sphere mixtures: a review.

    Science.gov (United States)

    Roth, Roland

    2010-02-17

    Hard-sphere systems are one of the fundamental model systems of statistical physics and represent an important reference system for molecular or colloidal systems with soft repulsive or attractive interactions in addition to hard-core repulsion at short distances. Density functional theory for classical systems, as one of the core theoretical approaches of statistical physics of fluids and solids, has to be able to treat such an important system successfully and accurately. Fundamental measure theory is up to date the most successful and most accurate density functional theory for hard-sphere mixtures. Since its introduction fundamental measure theory has been applied to many problems, tested against computer simulations, and further developed in many respects. The literature on fundamental measure theory is already large and is growing fast. This review aims to provide a starting point for readers new to fundamental measure theory and an overview of important developments.

  1. Hardness and microstructure of internally oxidized silver alloys

    Energy Technology Data Exchange (ETDEWEB)

    Prorok, B. C.; Park, J. H.; Goretta, K. C.; Balachandran, U.; McNallan, M. J.

    1999-11-11

    Alloys of Ag, Ag/1.12 at.% Mg, and Ag/0.25 at.% Mg-0.25 at.% Ni were internally oxidized at 450 to 825 C and their hardnesses and microstructure were observed. Microhardness profiles showed that hardness was high near the surface and decreased with depth into the sample. Microstructure contained regions of small and large grains, where region sizes were dependent on treatment temperature. Transitions between small- and large-grained regions were abrupt. Treatments at higher temperatures failed to alter grain structure, indicating that Mg-O clusters had indeed pinned the grain boundaries. Clustering was shown to affect the hardness of oxidized alloys, not only by inhibiting grain growth, but also by inhibiting dislocation motion.

  2. Deposition and tribological behaviour of sputtered carbon hard coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.; Camino, D.; Jones, A.H.S.; Teer, D.G. [Teer Coatings Ltd., Hartlebury (United Kingdom)

    2000-02-21

    The exceptional tribological properties of low deposition temperature sputtered carbon coatings (Graphit-iC coatings) have been recently reported. This paper describes the latest development of these coatings and particularly how, by an optimisation of the deposition parameters, it has been possible to obtain relative soft to very hard coatings with extremely low specific wear rates. The coatings have been deposited in a closed field unbalanced magnetron sputter ion plating (CFUBMSIP) installation. By applying the appropriate conditions of deposition, carbon coatings with hardness from 1500 to 4000 HV can be routinely deposited. Preliminary analytical results are presented in order to characterise such hard coatings: high-resolution transmission electron microscopy, scanning electron microscopy and X-ray diffraction analysis are some of the different techniques used for this work. Finally, a number of the applications are reported with tribological test results. (orig.)

  3. 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.

  4. 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.

  5. Estimating Hardness from the USDC Tool-Bit Temperature Rise

    Science.gov (United States)

    Bar-Cohen, Yoseph; Sherrit, Stewart

    2008-01-01

    A method of real-time quantification of the hardness of a rock or similar material involves measurement of the temperature, as a function of time, of the tool bit of an ultrasonic/sonic drill corer (USDC) that is being used to drill into the material. The method is based on the idea that, other things being about equal, the rate of rise of temperature and the maximum temperature reached during drilling increase with the hardness of the drilled material. In this method, the temperature is measured by means of a thermocouple embedded in the USDC tool bit near the drilling tip. The hardness of the drilled material can then be determined through correlation of the temperature-rise-versus-time data with time-dependent temperature rises determined in finite-element simulations of, and/or experiments on, drilling at various known rates of advance or known power levels through materials of known hardness. The figure presents an example of empirical temperature-versus-time data for a particular 3.6-mm USDC bit, driven at an average power somewhat below 40 W, drilling through materials of various hardness levels. The temperature readings from within a USDC tool bit can also be used for purposes other than estimating the hardness of the drilled material. For example, they can be especially useful as feedback to control the driving power to prevent thermal damage to the drilled material, the drill bit, or both. In the case of drilling through ice, the temperature readings could be used as a guide to maintaining sufficient drive power to prevent jamming of the drill by preventing refreezing of melted ice in contact with the drill.

  6. Hydration entropy change from the hard sphere model.

    Science.gov (United States)

    Graziano, Giuseppe; Lee, Byungkook

    2002-12-10

    The gas to liquid transfer entropy change for a pure non-polar liquid can be calculated quite accurately using a hard sphere model that obeys the Carnahan-Starling equation of state. The same procedure fails to produce a reasonable value for hydrogen bonding liquids such as water, methanol and ethanol. However, the size of the molecules increases when the hydrogen bonds are turned off to produce the hard sphere system and the volume packing density rises. We show here that the hard sphere system that has this increased packing density reproduces the experimental transfer entropy values rather well. The gas to water transfer entropy values for small non-polar hydrocarbons is also not reproduced by a hard sphere model, whether one uses the normal (2.8 A diameter) or the increased (3.2 A) size for water. At least part of the reason that the hard sphere model with 2.8 A size water produces too small entropy change is that the size of water is too small for a system without hydrogen bonds. The reason that the 3.2 A model also produces too small entropy values is that this is an overly crowded system and that the free volume introduced in the system by the addition of a solute molecule produces too much of a relief to this crowding. A hard sphere model, in which the free volume increase is limited by requiring that the average surface-to-surface distance between the solute and water molecules is the same as that between the increased-size water molecules, does approximately reproduce the experimental hydration entropy values.

  7. Role of water hardness in rinsing bacteria from the skin of processed broiler chickens

    Science.gov (United States)

    The effect of water hardness on the ability of water to rinse bacteria from the skin of processed broiler chickens was examined. Artificial hard water with a total hardness of 200 ppm (very hard water) was prepared by dissolving calcium chloride (CaCl2) and magnesium chloride hexahydrate (MgCl2 •6H2...

  8. 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.

  9. A New Hard Coat on Cover Layer for Cartridge-Free Blu-ray Disc

    Science.gov (United States)

    Han, Mi Young; Kang, Tae-Sik; Lee, Seong-Keun; Jang, Sung Hoon; Seo, Hun; Lee, Chang-Ho

    2004-07-01

    A new UV-curable hard coat resin with an excellent antifouling property has been developed. A 3-μm-thick hard coat layer was stacked onto a 97-μm-thick cover layer by spin coating. The characteristics of the hard coat layer, such as pencil hardness, microscratch resistance, adhesion, water contact angle and jitter, have been investigated.

  10. 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.

  11. Effects of Hardness on Pintle Rod Performance in the Universal and Retained Gas Samplers

    Energy Technology Data Exchange (ETDEWEB)

    BOGER, R.M.

    1999-11-18

    Interaction between hardness of the pintle rods and the retainer rings used in the core samplers is investigated. It is found that ordinary Rockwell C measurements are not sufficient and superficial hardness instruments are recommended to verify hardness since in-production hardness of pintle rods is found to vary widely and probably leads to some premature release of pistons in samplers.

  12. Dressed Hard States and Black Hole Soft Hair.

    Science.gov (United States)

    Mirbabayi, Mehrdad; Porrati, Massimo

    2016-11-18

    A recent, intriguing Letter by Hawking, Perry, and Strominger suggests that soft photons and gravitons can be regarded as black hole hair and may be relevant to the black hole information paradox. In this Letter we make use of factorization theorems for infrared divergences of the S matrix to argue that by appropriately dressing in and out hard states, the soft-quanta-dependent part of the S matrix becomes essentially trivial. The information paradox can be fully formulated in terms of dressed hard states, which do not depend on soft quanta.

  13. 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.

  14. Melatonin Effects on Hard Tissues: Bone and Tooth

    Directory of Open Access Journals (Sweden)

    Hong-Wen He

    2013-05-01

    Full Text Available Melatonin is an endogenous hormone rhythmically produced in the pineal gland under the control of the suprachiasmatic nucleus (SCN and the light/dark cycle. This indole plays an important role in many physiological processes including circadian entrainment, blood pressure regulation, seasonal reproduction, ovarian physiology, immune function, etc. Recently, the investigation and applications of melatonin in the hard tissues bone and tooth have received great attention. Melatonin has been investigated relative to bone remolding, osteoporosis, osseointegration of dental implants and dentine formation. In the present review, we discuss the large body of published evidence and review data of melatonin effects on hard tissues, specifically, bone and tooth.

  15. Theoretical Hardness of Zr3N4 Films

    Institute of Scientific and Technical Information of China (English)

    GAO Fa-Ming

    2011-01-01

    The structures,energetics and properties for orthohombic Zr3N4 and cubic Zr3N4 are calculated by first-principles calculations.The agreement between the predicted properties with available experimental data is excellent.The cubic phase has a smaller volume (by 11.2%) and a slightly higher total energy (by 0.3eV/pair),in comparison to the orthohombic phase.We elucidate the effects of stress on hardness of Zr3N4 films.The results show that the hardness of c-Zr3N4 increases up to 23% as the stress increases to 15 GPa.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Riya; De, Moumita; Roy, Sudakshina; Dey, Arjun; Biswas, Sampad K.; Middya, Tapas Ranjan; Mukhopadhyay, Anoop K. [CSIR-Central Glass and Ceramic Research Institute, Kolkata-700032, CSIR (India); Department of Physics, Jadavpur University, Kolkata-700032 (India); CSIR-Central Glass and Ceramic Research Institute, Kolkata-700032, CSIR (India)

    2012-06-05

    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{sup -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.

  17. Composition Gradient Hard Coatings by Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; LIN Guo-qiang; WANG Fu-gang

    2004-01-01

    Arc Ion Plating can be used to synthesize multi-component composition gradient hard coatings by adjusting arc currents of metal targets. The present work aims at a comprehensive description of such a technique. The examples of TiAl multi-layer alloy coatings and (Ti, M) N composition-gradient films were taken (M representing Zr, Nb etc.) for the purpose of explaining the working process and evaluating practical effects. The results show that this technique has the advantages of easy manipulation, rapid deposition, and wide composition range.Key Words: Arc Ion plating, hard coating, composition gradient coatings

  18. Recent Advances in Hard, Tough, and Low Friction Nanocomposite Coatings

    Institute of Scientific and Technical Information of China (English)

    A.A.Voevodin; J. S. Zabinski; C.Muratore

    2005-01-01

    Nanocomposite coatings demonstrate improved friction and wear responses under severe sliding conditions in extreme environments. This paper provides a review how thin film multilayers and nanocomposites result in hard, tough, low-friction coatings. Approaches to couple multilayered and nanocomposite materials with other surface engineering strategies to achieve higher levels of performance in a variety of tribological applications are also discussed. Encapsulating lubricious phases in hard nanocomposite matrices is one approach that is discussed in detail. Results from state-of-the-art "chameleon" nanocomposites that exhibit reversible adaptability to ambient humidity or temperature are presented.

  19. 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.

  20. Slip and flow of hard-sphere colloidal glasses.

    Science.gov (United States)

    Ballesta, P; Besseling, R; Isa, L; Petekidis, G; Poon, W C K

    2008-12-19

    We study the flow of concentrated hard-sphere colloidal suspensions along smooth, nonstick walls using cone-plate rheometry and simultaneous confocal microscopy. In the glass regime, the global flow shows a transition from Herschel-Bulkley behavior at large shear rate to a characteristic Bingham slip response at small rates, absent for ergodic colloidal fluids. Imaging reveals both the "solid" microstructure during full slip and the local nature of the "slip to shear" transition. Both the local and global flow are described by a phenomenological model, and the associated Bingham slip parameters exhibit characteristic scaling with size and concentration of the hard spheres.

  1. Free volume distribution of nearly jammed hard sphere packings

    Science.gov (United States)

    Maiti, Moumita; Sastry, Srikanth

    2014-07-01

    We calculate the free volume distributions of nearly jammed packings of monodisperse and bidisperse hard sphere configurations. These distributions differ qualitatively from those of the fluid, displaying a power law tail at large free volumes, which constitutes a distinct signature of nearly jammed configurations, persisting for moderate degrees of decompression. We reproduce and explain the observed distribution by considering the pair correlation function within the first coordination shell for jammed hard sphere configurations. We analyze features of the equation of state near jamming, and discuss the significance of observed asphericities of the free volumes to the equation of state.

  2. Dressed Hard States and Black Hole Soft Hair

    Science.gov (United States)

    Mirbabayi, Mehrdad; Porrati, Massimo

    2016-11-01

    A recent, intriguing Letter by Hawking, Perry, and Strominger suggests that soft photons and gravitons can be regarded as black hole hair and may be relevant to the black hole information paradox. In this Letter we make use of factorization theorems for infrared divergences of the S matrix to argue that by appropriately dressing in and out hard states, the soft-quanta-dependent part of the S matrix becomes essentially trivial. The information paradox can be fully formulated in terms of dressed hard states, which do not depend on soft quanta.

  3. Stochastic hard-sphere dynamics for hydrodynamics of nonideal fluids.

    Science.gov (United States)

    Donev, Aleksandar; Alder, Berni J; Garcia, Alejandro L

    2008-08-15

    A novel stochastic fluid model is proposed with a nonideal structure factor consistent with compressibility, and adjustable transport coefficients. This stochastic hard-sphere dynamics (SHSD) algorithm is a modification of the direct simulation Monte Carlo algorithm and has several computational advantages over event-driven hard-sphere molecular dynamics. Surprisingly, SHSD results in an equation of state and a pair correlation function identical to that of a deterministic Hamiltonian system of penetrable spheres interacting with linear core pair potentials. The fluctuating hydrodynamic behavior of the SHSD fluid is verified for the Brownian motion of a nanoparticle suspended in a compressible solvent.

  4. A generalized hard-sphere model for Monte Carlo simulation

    Science.gov (United States)

    Hassan, H. A.; Hash, David B.

    1993-01-01

    A new molecular model, called the generalized hard-sphere, or GHS model, is introduced. This model contains, as a special case, the variable hard-sphere model of Bird (1981) and is capable of reproducing all of the analytic viscosity coefficients available in the literature that are derived for a variety of interaction potentials incorporating attraction and repulsion. In addition, a new procedure for determining interaction potentials in a gas mixture is outlined. Expressions needed for implementing the new model in the direct simulation Monte Carlo methods are derived. This development makes it possible to employ interaction models that have the same level of complexity as used in Navier-Stokes calculations.

  5. 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.

  6. Finding small OBDDs for incompletely specified truth tables is hard

    DEFF Research Database (Denmark)

    Kristensen, Jesper Torp; Miltersen, Peter Bro

    2006-01-01

    We present an efficient reduction mapping undirected graphs G with n = 2^k vertices for integers k to tables of partially specified Boolean functions g: {0,1}^(4k+1) -> {0,1,*} so that for any integer m, G has a vertex colouring using m colours if and only if g has a consistent ordered binary dec...... decision diagram with at most (2m + 2)n^2 + 4n decision nodes. From this it follows that the problem of finding a minimum-sized consistent OBDD for an incompletely specified truth table is NP-hard and also hard to approximate...

  7. Finding small OBDDs for incompletely specified truth tables is hard

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro; Kristensen, Jesper Torp

    2006-01-01

    We present an efficient reduction mapping undirected graphs G with n = 2^k vertices for integers k to tables of partially specified Boolean functions g: {0,1}^(4k+1) -> {0,1,*} so that for any integer m, G has a vertex colouring using m colours if and only if g has a consistent ordered binary dec...... decision diagram with at most (2m + 2)n^2 + 4n decision nodes. From this it follows that the problem of finding a minimum-sized consistent OBDD for an incompletely specified truth table is NP-hard and also hard to approximate....

  8. 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.

  9. Social factors in occupational health: a history of hard hats.

    Science.gov (United States)

    Rosenberg, Beth; Levenstein, Charles

    2010-01-01

    Personal protective equipment (PPE) is the least desirable way to ensure workplace safety, and it is difficult to use consistently. Hard hats are different; they have cachet and are often worn even when they are not required. We investigated the history of this personal protective equipment to see if there were any lessons that could be applied to other forms of PPE. We learned that what makes hard hats special are social factors that are specific to a certain time and place. The importance of social factors illuminates the requirement that cultural and social norms of workers be included in any kind of worker safety and health training.

  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. Interspeaker Variability in Hard Palate Morphology and Vowel Production

    Science.gov (United States)

    Lammert, Adam; Proctor, Michael; Narayanan, Shrikanth

    2013-01-01

    Purpose: Differences in vocal tract morphology have the potential to explain interspeaker variability in speech production. The potential acoustic impact of hard palate shape was examined in simulation, in addition to the interplay among morphology, articulation, and acoustics in real vowel production data. Method: High-front vowel production from…

  12. 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...

  13. Guide to Working with Deaf and Hard of Hearing Students

    Science.gov (United States)

    PEPNet, 2009

    2009-01-01

    This handbook was created for professors, high school teachers and vocational teachers new to interacting with Deaf and Hard of Hearing students. Topics include a general understanding of deafness, classroom accommodations, and communication tips. Appendices include: (1) A Professor Shares His Experience; (2) A Vocational Rehabilitation Counselor…

  14. 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.

  15. Hardness Assurance Techniques for New Generation COTS Devices

    Science.gov (United States)

    Lee, C. I.; Rax, B. G.; Johnston, A. H.

    1996-01-01

    Hardness Assurance (HA) techniques and total dose radiation characterization data for new generation linear and COTS devices from various manufacturers are presented. A bipolar op amp showed significant degradation at HDR, not at low dose rate environment. New generation low-power op amps showed more degradation at low voltage applications. HA test techniques for COTS devices are presented in this paper.

  16. Alkalinity and hardness: Critical but elusive concepts in aquaculture

    Science.gov (United States)

    Total alkalinity and total hardness are familiar variables to those involved in aquatic animal production. Aquaculturists – both scientists and practitioners alike – tend to have some understanding of the two variables and of methods for adjusting their concentrations. The chemistry and the biolog...

  17. Statistical Modeling for Radiation Hardness Assurance: Toward Bigger Data

    Science.gov (United States)

    Ladbury, R.; Campola, M. J.

    2015-01-01

    New approaches to statistical modeling in radiation hardness assurance are discussed. These approaches yield quantitative bounds on flight-part radiation performance even in the absence of conventional data sources. This allows the analyst to bound radiation risk at all stages and for all decisions in the RHA process. It also allows optimization of RHA procedures for the project's risk tolerance.

  18. The Classification of Science Literatures by Their "Hardness."

    Science.gov (United States)

    Houser, Lloyd

    1986-01-01

    Examines the literature on the myth of "hard science-soft science" as a means of defining scientific specialties and classifying science literature, and discusses some shortcomings of scholarship in library and information science. Use of Toulmin's categorization of sciences to organize the literature and provide access for scientists is…

  19. Is osmium diboride an ultra-hard material?

    Science.gov (United States)

    Yang, Jun; Sun, Hong; Chen, Changfeng

    2008-06-11

    We report first-principles calculations of ideal tensile and shear strength for the recently synthesized orthorhombic OsB2 that is a primary example of a new class of ultra-hard materials synthesized by combining small, light, and covalent elements with large, electron-rich transition metals. Our calculations show that the shear strength on the (001) plane is highly anisotropic with a low peak stress of 9.1 GPa in the (001)[010] shear direction but a much higher peak stress of 26.9 GPa in the (001)[100] direction. The strong resistance against (001)[100] shear deformation prevents the indenter from making a deep imprint, giving rise to a high Vickers hardness on the (001) plane, despite the weak shear strength in the (001)[010] shear direction. The calculated peak stress of 26.9 GPa in the (001)[100] shear direction agrees well with the 30 GPa Vickers hardness observed experimentally on the (001) plane in OsB2. However, the weak shear strength (9.1 GPa) in the (001)[010] shear direction severely limits its application as abrasives and cutting tools for ferrous metals as well as scratch-resistance coatings. Our results highlight the importance of understanding atomistic deformation modes under various loading conditions in designing new ultra-hard materials.

  20. Knoop Hardness - Apparent Yield Stress Relationship in Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Swab, Jeffrey J [ORNL; LaSalvia, Jerry [U.S. Army research Laboratory, Adelphi, MD; Wereszczak, Andrew A [ORNL; Strong, Kevin T [ORNL; Danna, Dominic [U.S. Army research Laboratory, Adelphi, MD; Ragan, Meredith E [ORNL; Ritt, Patrick J [ORNL

    2012-01-01

    In Tabor's classical studies of the deformation of metals, the yield stress (Y) and hardness (H) were shown to be related according to H/Y {approx} 3 for complete or fully plastic deformation. Since then it has been anecdotally shown for ceramics that this ratio is <3. Interest exists to explore this further so Hertzian indentation was used to measure the apparent yield stress of numerous ceramics and metals and their results were compared with each material's load-dependent Knoop hardness. The evaluated ceramics included standard reference materials for hardness (silicon nitride and tungsten carbide), silicon carbide, alumina, and glass. Several steel compositions were also tested for comparison. Knoop hardness measurements at 19.6 N (i.e., toward 'complete or fully plastic deformation'), showed that 2 < H/Y < 3 for the metals and 0.8 < H/Y < 1.8 for the glasses and ceramics. Being that H/Y {ne} 3 for the ceramics indicates that Tabor's analysis is either not applicable to ceramics or that full plastic deformation is not achieved with a Knoop indentation or both.

  1. Performance Analysis of Hard Iterative Channel Estimation in Turbo Equalization

    Institute of Scientific and Technical Information of China (English)

    DENG Yongjun; YANG Zhixing; PAN Changyong; WANG Jun

    2006-01-01

    Reasonable bit error rate performance requires perfect channel state information (CSI) in traditional turbo equalization (TE), which is hard to obtain in practice. Soft and hard iterative algorithms have been developed to address the channel estimation problem with the performance of the soft iterative channel estimate based on the recursive least square algorithm. This paper presents an analysis of the performance of hard iterative channel estimation (HICE) based on the least mean square algorithm. The analysis uses a cost function with the hard decision on the TE output. An iterative channel correction (ICC) algorithm based on the gradient descent algorithm is used to iteratively minimize the cost function. The simulation results agree with the theoretical lower bound for the mean square error (MSE) of the estimated channels. Simulations show that, given an imperfect CSI with an MSE below the upper bound, the linear minimum mean squared error TE (LMMSE-TE) using the ICC has only small performance degradation compared to that with a perfect CSI, while the traditional LMMSE-TE suffers from severe error floor effect even with more iterations.

  2. The Hardness of Finding Linear Ranking Functions for Lasso Programs

    Directory of Open Access Journals (Sweden)

    Amir M. Ben-Amram

    2014-08-01

    Full Text Available Finding whether a linear-constraint loop has a linear ranking function is an important key to understanding the loop behavior, proving its termination and establishing iteration bounds. If no preconditions are provided, the decision problem is known to be in coNP when variables range over the integers and in PTIME for the rational numbers, or real numbers. Here we show that deciding whether a linear-constraint loop with a precondition, specifically with partially-specified input, has a linear ranking function is EXPSPACE-hard over the integers, and PSPACE-hard over the rationals. The precise complexity of these decision problems is yet unknown. The EXPSPACE lower bound is derived from the reachability problem for Petri nets (equivalently, Vector Addition Systems, and possibly indicates an even stronger lower bound (subject to open problems in VAS theory. The lower bound for the rationals follows from a novel simulation of Boolean programs. Lower bounds are also given for the problem of deciding if a linear ranking-function supported by a particular form of inductive invariant exists. For loops over integers, the problem is PSPACE-hard for convex polyhedral invariants and EXPSPACE-hard for downward-closed sets of natural numbers as invariants.

  3. Hard x-ray spectroscopy for proton flare prediction

    Science.gov (United States)

    Garcia, Howard A.; Farnik, Frantisek; Kiplinger, Alan L.

    1998-11-01

    High energy interplanetary proton events can jeopardize vital military and civilian spacecraft by disrupting logical circuits and by actually damaging spacecraft electronic components. Studies of solar hard x-rays indicate that high-energy proton events observed near Earth are highly associated with an uncommon type of solar flare exhibiting temporal progressively hardening hard x-ray spectra. A hard x-ray spectrometer is being developed by the Czech Astronomical Institute to provide a test bed for evaluating this phenomenon as a possible proton-storm prediction method. The instrument is designed to measure hard x-ray spectra in a high fluence, high-energy particle background environment such as that found at geosynchronous altitude. This experiment has been selected for space flight by the DoD Space Test Program and will fly aboard the Department of Energy satellite, Multi-spectral thermal Imager, scheduled for a three year mission, beginning in late 1999. The timing of this mission, fortuitously, coincides with the experiment are: 1) to evaluate the efficacy of this type of solar instrument in predicting interplanetary proton storms; 2) to study the high-energy physics of solar flares in concert with the premier flight of the NOAA soft x-ray imaging telescope, SXI, on the GOES 12 weather satellite and other solar mission. If the first goal is demonstrated by this mission, continuous monitoring of the Sun for proton events could become operational from geo-synchronous orbit during solar cycle 24.

  4. Why HPT Will Continue to Be a Hard Sell

    Science.gov (United States)

    Pearlstein, Richard B.

    2012-01-01

    Most executives have not heard of human performance technology (HPT), but a recent Google search showed 25 times more Google hits for "lean six sigma" than for "human performance technology." This article describes five factors that make HPT a hard sell: (1) HPT is not part of standard business jargon, (2) organizational executives associate…

  5. Nucleation at hardness indentations in cold rolled Al

    DEFF Research Database (Denmark)

    Xu, C.L.; Zhang, Yubin; Wu, G.L.

    2015-01-01

    Nucleation of recrystallization near hardness indentations has been investigated in slightly cold rolled high purity aluminium. Samples were cold rolled to 12% and 20% reductions in thickness and indentations were done with two different loads (500 g and 2000 g). The samples were annealed at 300 ...... and stored energy distributions and thus on nucleation are discussed....

  6. A New Perturbed Hard-Sphere Equation of State

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new equation of state based on hard-sphere perturbed theory was developed. This equation combined the CS repulsive term and Guo-Du attractive term. Parameters of 38 substances were estimated, the pressure-volume-temperature properties were calculated and compared with two other equations. The results show that this equation is more accurate.

  7. INTEGRAL survey of the Cassiopeia region in hard X rays

    CERN Document Server

    Den Hartog, P R; Hermsen, W; Kuiper, L; Vink, J; in 't Zand, J J M

    2006-01-01

    We report on the results of a deep 1.6 Ms INTEGRAL observation of the Cassiopeia region performed from December 2003 to February 2004. Eleven sources were detected with the imager IBIS-ISGRI at energies above 20 keV, including three new hard X-ray sources. Most remarkable is the discovery of hard X-ray emission from the anomalous X-ray pulsar 4U 0142+61, which shows emission up to \\~150 keV with a very hard power-law spectrum with photon index Gamma = 0.73 +/- 0.17. We derived flux upper limits for energies between 0.75 MeV and 30 MeV using archival data from the Compton telescope COMPTEL. In order to reconcile the very hard spectrum of 4U 0142+61 measured by INTEGRAL with the COMPTEL upper limits, the spectrum has to bend or break between ~75 keV and ~750 keV. 1E 2259+586, another anomalous X-ray pulsar in this region, was not detected. INTEGRAL and COMPTEL upper limits are provided. The new INTEGRAL sources are IGR J00370+6122 and IGR J00234+6144. IGR J00370+6122 is a new supergiant X-ray binary with an orb...

  8. Effective action for hard thermal loops in gravitational fields

    Directory of Open Access Journals (Sweden)

    R.R. Francisco

    2016-05-01

    Full Text Available We examine, through a Boltzmann equation approach, the generating action of hard thermal loops in the background of gravitational fields. Using the gauge and Weyl invariance of the theory at high temperature, we derive an explicit closed-form expression for the effective action.

  9. Release of ‘UI Platinum’ hard white spring wheat

    Science.gov (United States)

    ‘UI Platinum’ (Reg. No. CV------, PI 672533) hard white spring wheat (Triticum aestivum L.) was developed by the Idaho Agricultural Experiment Station and released in 2014. UI Platinum was derived from the cross ‘Blanca Grande’ x ‘Jerome’ and tested under experimental numbers A01178S, IDO694, and I...

  10. Educing GPDs from Amplitudes of Hard Exclusive Processes

    CERN Document Server

    Polyakov, M V

    2007-01-01

    The dual parametrization of generalized parton distributions (GPDs) is considered in details. We discuss which part of information about hadron structure encoded in GPDs [part of total GPD image] can be restored from the known amplitude of a hard exclusive process. The physics content of this partial image is analyzed.

  11. Research on overlaying welding rod of high hardness maraging steel

    Institute of Scientific and Technical Information of China (English)

    PAN Yong-ming; CHEN Shao-wei

    2006-01-01

    The development of new maraging steel overlaying welding rod,which contains Co,Mo,W and V alloy,solved the problems of poor homogeneity of hardness and mechanical process, prolonged the service life of wear-resistant components and increased the productive efficiency of repairing,greatly benefiting the national economy.

  12. Phase diagram of a system of hard ellipsoids

    NARCIS (Netherlands)

    Frenkel, D.; Mulder, B.M.; McTaque, J.P.

    1984-01-01

    The phase diagram of a system of hard ellipsoids of revolution was investigated by means of constant-pressure Monte Carlo simulation. Prolate as well as oblate ellipsoids were considered. The results for the isotherms of the system at several different values of the length-to-breadth ratio are prese

  13. Experimental validation of micro endmill design for hard milling application

    NARCIS (Netherlands)

    Li, P.; Hoogstrate, A.M.; Oosterling, J.A.J.; Langen, H.H.; Munnig Schmidt, R.

    2008-01-01

    Abstract: In experimental investigations of micro milling of hardened tool steel SAE H11, with a hardness of 56 HRC, with commercially available micro square endmills of Ø 0.5mm, it was observed that the endmills suffered from severe tool wear/failure. Because of these problems, the quality of the m

  14. Hardness analysis of cubic metal mononitrides from first principles

    Science.gov (United States)

    Fulcher, B. D.; Cui, X. Y.; Delley, B.; Stampfl, C.

    2012-05-01

    Density functional theory calculations are performed to evaluate the hardness of various cubic metal nitrides: rocksalt TiN, VN, ZrN, NbN, AlN, and SiN; zincblende AlN and BN; and diamond C for comparison. The isotropic elastic stiffness constants cij, bulk modulus K, shear modulus G, Young's modulus E, and isotropic Poisson's ratio ν¯ are calculated. From simulated uniaxial stress-strain curves, ideal strength values σmax in the [100], [110], and [111] directions are also evaluated for all systems. In particular, rocksalt AlN is found to possess both high elastic moduli and ideal strength. These quantities are then compared for correlations with existing experimental Vicker's hardness data. The bulk modulus is found to be a poor indicator of hardness, while E, G, 1/ν¯, and σmax all exhibit stronger correlations. With a view to circumvent the need to run computationally expensive relaxation steps, different methodologies for approximating uniaxial stress-strain curves are introduced. Utilizing the anisotropic Poisson's ratio to approximate the relaxed transverse lattice parameters at a given axial strain is a good approximation to stress-strain curves, and the ideal strengths obtained in this way exhibit strong correlations to experimental Vicker's hardness values.

  15. Process-microstructure-hardness relations of electrodeposited nickel layers

    DEFF Research Database (Denmark)

    Rasmussen, Anette Alsted; Møller, Per; Somers, Marcel A. J.

    2006-01-01

    and scanning electron microscopy and X-ray diffraction; the Vickers microhardness was measured in cross-sections. The present article is meant as a reference for forthcoming articles on the investigation of various strengthening mechanisms on the microstructure, hardness and thermal stability of Ni (alloy...

  16. Hard sphere colloidal dispersions: Mechanical relaxation pertaining to thermodynamic forces

    NARCIS (Netherlands)

    Mellema, J.; Kruif, de C.G.; Blom, C.; Vrij, A.

    1987-01-01

    The complex viscosity of sterically stabilized (hard) silica spheres in cyclohexane has been measured between 80 Hz and 170 kHz with torsion pendulums and a nickel tube resonator. The observed relaxation behaviour can be attributed to the interplay of hydrodynamic and thermodynamic forces. The valid

  17. 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

  18. 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...

  19. High-hardness ceramics based on boron carbide fullerite derivatives

    Science.gov (United States)

    Ovsyannikov, D. A.; Popov, M. Yu.; Perfilov, S. A.; Prokhorov, V. M.; Kulnitskiy, B. A.; Perezhogin, I. A.; Blank, V. D.

    2017-02-01

    A new type of ceramics based on the phases of fullerite derivatives and boron carbide B4C is obtained. The material is synthesized at a temperature of 1500 K and a relatively low pressure of 4 GPa; it has a high hardness of 45 GPa and fracture toughness of 15 MPa m1/2.

  20. Hard and Soft Excitation Regimes of Kerr Frequency Combs

    CERN Document Server

    Matsko, Andrey B; Ilchenko, Vladimir S; Seidel, David; Maleki, Lute

    2011-01-01

    We theoretically study the stability conditions and excitation regimes of hyper-parametric oscillation and Kerr frequency comb generation in continuously pumped nonlinear optical resonators possessing anomalous group velocity dispersion. We show that both hard and soft excitation regimes are possible in the resonators. Selection between the regimes is achieved via change in the parameters of the pumping light.

  1. Radiation-hard polycrystalline mercuric iodide semiconductor particle counters

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, M. [Hebrew Univ., Jerusalem (Israel)]|[Sandia National Laboratories, Livermore Ca 94556 (United States); Zuck, A.; Melekhov, L.; Nissenbaum, J. [Hebrew Univ., Jerusalem (Israel); Turchetta, R.; Dulinski, W.; Husson, D.; Riester, J.L. [LEPSI (ULP/IN2P3), Strasbourg (France)

    1998-06-01

    Mercuric iodide polycrystalline radiation detectors, which can act as nuclear particle counters and for large area imaging devices, have been fabricated using three different methods. Response to X- and gamma rays, beta particles and to 100GeV muons, as well as radiation hardness results are briefly described. (orig.) 8 refs.

  2. Computer simulation of hard-core models for liquid crystals

    NARCIS (Netherlands)

    Frenkel, D.

    1987-01-01

    A review is presented of computer simulations of liquid crystal systems. It will be shown that the shape of hard-core particles is of crucial importance for the stability of the phases. Both static and dynamic properties of the systems are obtained by means of computer simulation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Manuel Frondel; Rainer Kambeck; Christoph M. Schmidt [Rheinisch-Westfaelisches Institut fuer Wirtschaftsforschung (RWI Essen), Essen (Germany)

    2007-07-15

    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 mid-1990s, reaching a peak at 6.7 billion in 1996. While these subsidies have been continually shrinking since then, settling at 2.7 billion euro 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, the rapid abolition of these subsidies is recommended, not only in Germany, where in real terms the accumulated amount of subsidies has now far exceeded 165 billion euro, but also all across Europe. 31 refs., 5 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Frondel, Manuel [Rheinisch-Westfaelisches Institut fuer Wirtschaftsforschung RWI Essen, Hohenzollernstr. 1-3, 45128 Essen (Germany)]. E-mail: frondel@rwi-essen.de; Kambeck, Rainer [Rheinisch-Westfaelisches Institut fuer Wirtschaftsforschung RWI Essen, Hohenzollernstr. 1-3, 45128 Essen (Germany); Schmidt, Christoph M. [Rheinisch-Westfaelisches Institut fuer Wirtschaftsforschung RWI Essen, Hohenzollernstr. 1-3, 45128 Essen (Germany)

    2007-07-15

    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.

  5. Hard-Hat Detection for Construction Safety Visualization

    Directory of Open Access Journals (Sweden)

    Kishor Shrestha

    2015-01-01

    Full Text Available In 2012, 775 fatalities were recorded, and many more were injured at construction sites in the United States. Of these, 415 fatalities (54% were due to fall, slips, and trips as well as being struck by falling objects. In order to decrease fatalities at construction sites to these types of events, the Occupational Safety and Health Administration (OSHA provides Fall Prevention and OSHA-10 trainings to construction workers. Moreover, safety personnel monitor whether the workers use personal protective equipment (PPE properly. Data shows that construction fatalities have decreased by 2% annually since 1994; however, the owners still are not satisfied with this result. Various studies have shown that fall is the biggest contributor for construction fatalities. One study showed that half of the fall fatalities were because the workers either had not used PPEs or had not used them properly. In addition, studies showed that, with proper use of hard hats, the fatalities due to fall, slips, trips, and being struck by falling objects could be reduced. This study developed and tested a hard-hat detection tool that uses image-processing techniques to identify whether workers are wearing hard hats. The tool dispatches warning messages if the workers do not use hard hats.

  6. 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…

  7. Self-assembly in colloidal hard-sphere systems

    NARCIS (Netherlands)

    Filion, L.C.

    2011-01-01

    In this thesis, we examine the phase behaviour and nucleation in a variety of hard-sphere systems. In Chapter 1 we present a short introduction and describe some of the simulation techniques used in this thesis. One of the main difficulties in predicting the phase behaviour in colloidal, atomic and

  8. 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 $\

  9. Simulating colloids with Baxter's adhesive hard sphere model

    NARCIS (Netherlands)

    Miller, M.A.; Frenkel, D.

    2004-01-01

    The structure of the Baxter adhesive hard sphere fluid is examined using computer simulation. The radial distribution function (which exhibits unusual discontinuities due to the particle adhesion) and static structure factor are calculated with high accuracy over a range of conditions and compared w

  10. Simulation of the adhesive-hard-sphere model

    NARCIS (Netherlands)

    Kranendonk, W.G.T.; Frenkel, D.

    1988-01-01

    Monte Carlo simulations of the three-dimensional sticky-hard-sphere system are presented. A new modified Monte Carlo algorithm has been developed which makes it possible to explore the phase diagram for a large region of both the packing fraction and the stickiness parameter t. The phase diagram is

  11. Transport properties of the rough hard sphere fluid.

    Science.gov (United States)

    Kravchenko, Olga; Thachuk, Mark

    2012-01-28

    Results are presented of a systematic study of the transport properties of the rough hard sphere fluid. The rough hard sphere fluid is a simple model consisting of spherical particles that exchange linear and angular momenta, and energy upon collision. This allows a study of the sole effect of particle rotation upon fluid properties. Molecular dynamics simulations have been used to conduct extensive benchmark calculations of self-diffusion, shear and bulk viscosity, and thermal conductivity coefficients. As well, the validity of several kinetic theory equations have been examined at various levels of approximation as a function of density and translational-rotational coupling. In particular, expressions from Enskog theory using different numbers of basis sets in the representation of the distribution function were tested. Generally Enskog theory performs well at low density but deviates at larger densities, as expected. The dependence of these expressions upon translational-rotational coupling was also examined. Interestingly, even at low densities, the agreement with simulation results was sometimes not even qualitatively correct. Compared with smooth hard sphere behaviour, the transport coefficients can change significantly due to translational-rotational coupling and this effect becomes stronger the greater the coupling. Overall, the rough hard sphere fluid provides an excellent model for understanding the effects of translational-rotational coupling upon transport coefficients.

  12. 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...

  13. The Hard Truth: Problems and Issues in Urban School Reform

    Science.gov (United States)

    Yisrael, Sean

    2012-01-01

    "The Hard Truth" is a book written for principals and school administrators who want to implement effective change. The topics of the book candidly discuss the problems, people, and issues that get in the way of true school reform; and what building level principals can personally do attain the best possible outcomes.

  14. Hard X-rays and associated weak decimetric bursts

    Science.gov (United States)

    Sawant, H. S.; Lattari, C. J. B.; Benz, A. O.; Dennis, B. R.

    1990-01-01

    Results are presented of observations (made with the Hard X-Ray Burst Spectrometer on the SMM and with the Itapetinga antenna) that unambiguously show associations of hard X-ray bursts with RS-type III bursts between 16:46 UT and 16:52 UT on July 9, 1985. The comparison between the hard X-ray and the radio observations shows a clear association, in at least 13 cases, of the hard X-ray and the decimetric RS bursts. On the average, the X-ray peaks were delayed from the peak of the RS bursts at 1.6 Ghz by about 400 msec. It is shown that, if the time comparisons are made between the peak of the radio pulse and the start of the X-ray burst, the delays are consistent with an electron travel time with a velocity of about 0.3 c from the 800 MHz plasma level to the lower corona, assuming that the radio emission is at the second harmonic.

  15. Rowlinson’s concept of an effective hard sphere diameter

    Science.gov (United States)

    Henderson, Douglas

    2010-01-01

    Attention is drawn to John Rowlinson’s idea that the repulsive portion of the intermolecular interaction may be replaced by a temperature-dependent hard sphere diameter. It is this approximation that made the development of perturbation theory possible for realistic fluids whose intermolecular interactions have a steep, but finite, repulsion at short separations. PMID:20953320

  16. Rowlinson's concept of an effective hard sphere diameter.

    Science.gov (United States)

    Henderson, Douglas

    2010-01-01

    Attention is drawn to John Rowlinson's idea that the repulsive portion of the intermolecular interaction may be replaced by a temperature-dependent hard sphere diameter. It is this approximation that made the development of perturbation theory possible for realistic fluids whose intermolecular interactions have a steep, but finite, repulsion at short separations.

  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. Registration of ‘Sprinter’ hard red winter wheat

    Science.gov (United States)

    High grain protein concentration and stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici Eriks.) resistance are important traits for hard red winter wheat (Triticum aestivum L.) cultivars produced in the Pacific Northwest region of the United States. The objective of this research wa...

  19. IKONPAINT -- Ikon and GWM window to Inkjet Hard-copy

    Science.gov (United States)

    Page, Clive G.; Mellor, G. R.

    IKONPAINT provides ``push-button'' colour hard-copy from the Ikon screen or from a GWM window to an inkjet printer. The DEC Companion Colour Printer (LJ250/LJ252) and the Hewlett-Packard Paintjet are both supported. These printers normally take 8 by 11 inch fan-fold paper but single transparency sheets can be hand-fed.

  20. 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

  1. Microstructure and macroscopic properties of polydisperse systems of hard spheres

    NARCIS (Netherlands)

    Ogarko, Vitaliy Anatolyevich

    2014-01-01

    This dissertation describes an investigation of systems of polydisperse smooth hard spheres. This includes the development of a fast contact detection algorithm for computer modelling, the development of macroscopic constitutive laws that are based on microscopic features such as the moments of the

  2. 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.

  3. Replication-based Inference Algorithms for Hard Computational Problems

    OpenAIRE

    Alamino, Roberto C.; Neirotti, Juan P.; Saad, David

    2013-01-01

    Inference algorithms based on evolving interactions between replicated solutions are introduced and analyzed on a prototypical NP-hard problem - the capacity of the binary Ising perceptron. The efficiency of the algorithm is examined numerically against that of the parallel tempering algorithm, showing improved performance in terms of the results obtained, computing requirements and simplicity of implementation.

  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. HXMT satellite for space hard X-ray observation

    Science.gov (United States)

    Wu, Y.; Ren, D.; You, Z.

    Space hard X-ray in the energy band from 10Kev to 250KeV is very important to the research of high energy astrophysical processes, especially some of the fundamental problems in astrophysics. Due to imaging difficulty in the hard X-ray band, Observations made over this band is comparatively less than other bands such as soft X-ray and gamma -ray. Up to now, there has been no hard X ray all sky- survey of high sensitivity. Based on the Direct Demodulation imaging method recently developed, the Hard X- ray Modulation Telescope(HXMT) mission is proposed under the Major State Basic Research Development Program of China. The scientific objective of HXMT mission is to realize the first hard X-ray all sky survey of high sensitivy and angular resolution in the world, and to present the first detailed sky map of hard X r a y - distribution. In this article, the physical basis, the imaging principle and the basic structure of HXMT are briefly introduced. The expected angular resolution of observation and position accuracy of radiant source are 2' and 0.2' respectively. Based on the analysis of the mission requirement of HXMT, the mission design of HXMT satellite is presented in which the concept of integrative design approach is presented and implemented. The design of spacecraft subsystems such as strcuture,C&DH and energy are also introduced. To meet the high precision demand of the attitude determination of HXMT, a new Attitude Determination &Control Subsystem(ADCS) scheme is presented in which the Microminiature Inertial Measurement Unit(MIMU) is employed as one of the key attitude sensors. Combined with star tracker, the expected attitude measurement accuracy is 0.01° in the normal mission mode. Based on all these thoughts, the ADCS is analyzed and its general design is presented in the paper. As the first chinese space hard X-ray observatory, the design approach of HXMT satellite is also helpful for other space exploration missions such as solar activity inspection

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

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, Nobuyuki, E-mail: fujisawa@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Yamagata, Takayuki, E-mail: yamagata@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Takano, Shotaro; Saito, Kengo [Graduate School of Science and Technology, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Morita, Ryo; Fujiwara, Kazutoshi; Inada, Fumio [Central Research Institute of Electric Power Industry, 2-11-1, Iwatokita, Komae, Tokyo 201-8511 (Japan)

    2015-07-15

    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. Loose abrasive lapping hardness of optical glasses and its interpretation.

    Science.gov (United States)

    Lambropoulos, J C; Xu, S; Fang, T

    1997-03-01

    We present an interpretation of the lapping hardness of commercially available optical glasses in terms of a micromechanics model of material removal by subsurface lateral cracking. We analyze data on loose abrasive microgrinding, or lapping at fixed nominal pressure, for many commercially available optical glasses in terms of this model. The Schott and Hoya data on lapping hardness are correlated with the results of such a model. Lapping hardness is a function of the mechanical properties of the glass: The volume removal rate increases approximately linearly with Young's modulus, and it decreases with fracture toughness and (approximately) the square of the Knoop hardness. The microroughness induced by lapping depends on the plastic and elastic properties of the glass, depending on abrasive shape. This is in contrast to deterministic microgrinding (fixed infeed rate), where it is determined from the plastic and fracture properties of the glass. We also show that Preston's coefficient has a similar dependence as lapping hardness on glass mechanical properties, as well as a linear dependence on abrasive size for the case of brittle material removal. These observations lead to the definition of an augmented Preston coefficient during brittle material removal. The augmented Preston coefficient does not depend on glass material properties or abrasive size and thus describes the interaction of the glass surface with the coolant-immersed abrasive grain and the backing plate. Numerical simulations of indentation are used to locate the origin of subsurface cracks and the distribution of residual surface and subsurface stresses, known to cause surface (radial) and subsurface (median, lateral) cracks.

  8. Extended hard-sphere model and collisions of cohesive particles.

    Science.gov (United States)

    Kosinski, Pawel; Hoffmann, Alex C

    2011-09-01

    In two earlier papers the present authors modified a standard hard-sphere particle-wall and particle-particle collision model to account for the presence of adhesive or cohesive interaction between the colliding particles: the problem is of importance for modeling particle-fluid flow using the Lagrangian approach. This technique, which involves a direct numerical simulation of such flows, is gaining increasing popularity for simulating, e.g., dust transport, flows of nanofluids and grains in planetary rings. The main objective of the previous papers was to formally extend the impulse-based hard-sphere model, while suggestions for quantifications of the adhesive or cohesive interaction were made. This present paper gives an improved quantification of the adhesive and cohesive interactions for use in the extended hard-sphere model for cases where the surfaces of the colliding bodies are "dry," e.g., there is no liquid-bridge formation between the colliding bodies. This quantification is based on the Johnson-Kendall-Roberts (JKR) analysis of collision dynamics but includes, in addition, dissipative forces using a soft-sphere modeling technique. In this way the cohesive impulse, required for the hard-sphere model, is calculated together with other parameters, namely the collision duration and the restitution coefficient. Finally a dimensional analysis technique is applied to fit an analytical expression to the results for the cohesive impulse that can be used in the extended hard-sphere model. At the end of the paper we show some simulation results in order to illustrate the model.

  9. 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.

  10. Hard target penetrator explosive development optimization of fragment, blast and survivability properties of explosives for hard target applications

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, R. L., LLNL

    1997-05-01

    Several new explosives have been developed for hard target and related applications. Materials having energy densities as high as 20 KJ/cc have been made. Mid-scale field trials have been carried out at Eglin Air Force Base. Fragmentation improvements 150% that of Tritonal have been attained.

  11. Ballistic Testing of Australian Bisalloy Steel for Armor Applications

    Science.gov (United States)

    2007-06-01

    as per MIL-A-12560H. TEST DATA Tables 4-7 show the nominal thickness; Brinell hardness (HB); angle of obliquity with zero being normal to...1 DEFENCE RSCH FORT HALSTEAD KENT TN14 7BP UNITED KINGDOM 1 CARLOS III U C NAVARRO ESCUELA PO C/. BUTARQUE 28911 LEGANES MADR

  12. Hardness of kamacite and shock histories of 119 meteorites.

    Science.gov (United States)

    Jain, A. V.; Gordon, R. B.; Lipschutz, M. E.

    1972-01-01

    Use of metallographic and X-ray diffraction techniques to study the shock histories of 119 iron and stony-iron meteorites, and measurement of the hardness of kamacite in these specimens and in artificially shocked-unannealed and annealed meteorite specimens. Shock increases kamacite hardness, but complications introduced by other physical and chemical properties of meteorites limit its utility as a shock indicator. About 50% of the meteorites studied show evidence for preterrestrial shock loading to pressures of greater than or equal to 130 kb, and 40% have not been shocked to such high pressures. The remaining meteorites have been heat-altered in such a way that their shock histories cannot be determined explicitly. These results, together with those obtained previously, indicate that the plurality, if not the majority, of all iron and stony-iron meteorites sampled by the earth were shocked to pressures of greater than or equal to 130 kb during preterrestrial collisions between asteroidal-sized objects.

  13. Automatic Cataract Hardness Classification Ex Vivo by Ultrasound Techniques.

    Science.gov (United States)

    Caixinha, Miguel; Santos, Mário; Santos, Jaime

    2016-04-01

    To demonstrate the feasibility of a new methodology for cataract hardness characterization and automatic classification using ultrasound techniques, different cataract degrees were induced in 210 porcine lenses. A 25-MHz ultrasound transducer was used to obtain acoustical parameters (velocity and attenuation) and backscattering signals. B-Scan and parametric Nakagami images were constructed. Ninety-seven parameters were extracted and subjected to a Principal Component Analysis. Bayes, K-Nearest-Neighbours, Fisher Linear Discriminant and Support Vector Machine (SVM) classifiers were used to automatically classify the different cataract severities. Statistically significant increases with cataract formation were found for velocity, attenuation, mean brightness intensity of the B-Scan images and mean Nakagami m parameter (p hardness characterization and automatic classification.

  14. Perforation of the hard palate due to tuberculosis

    Directory of Open Access Journals (Sweden)

    Syed Ahmed Zaki

    2012-01-01

    Full Text Available Tuberculosis (TB of the hard palate is rare and usually secondary to pulmonary TB. We present a case of a 7-year-old boy who presented with difficulty in swallowing solid foods, low-grade fever and loss of weight. Oral cavity examination showed perforation of the hard palate with an irregular, undermined margin and a necrotic base. Chest X-ray showed homogeneous opacity in the right upper zone. Fine-needle aspiration of the cervical lymph nodes showed granular caseous necrosis and granuloma composed of epitheliod cells and histiocytes. In view of the clinical presentation and evidence of pulmonary and lymph node TB, the palatal perforation was most likely due to TB. Patient was started on antituberculous therapy and is on regular follow-up.

  15. Expectation Maximization for Hard X-ray Count Modulation Profiles

    CERN Document Server

    Benvenuto, Federico; Piana, Michele; Massone, Anna Maria

    2013-01-01

    This paper is concerned with the image reconstruction problem when the measured data are solar hard X-ray modulation profiles obtained from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI)} instrument. Our goal is to demonstrate that a statistical iterative method classically applied to the image deconvolution problem is very effective when utilized for the analysis of count modulation profiles in solar hard X-ray imaging based on Rotating Modulation Collimators. The algorithm described in this paper solves the maximum likelihood problem iteratively and encoding a positivity constraint into the iterative optimization scheme. The result is therefore a classical Expectation Maximization method this time applied not to an image deconvolution problem but to image reconstruction from count modulation profiles. The technical reason that makes our implementation particularly effective in this application is the use of a very reliable stopping rule which is able to regularize the solution providing, ...

  16. 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...... temperature has an average hardness of 35.31 GPa, slightly larger than SiO2 stishovite, which is often referred to as the third hardest material after diamond and cubic boron nitride. The cubic phase is stable up to 1673 K in air. At 1873 K, alpha -and beta -Si3N4 phases are observed, indicating a phase...... transformation sequence of c-to-alpha -to-beta -Si3N4 phases....

  17. 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.

  18. Hard Loops, Soft Loops, and High Density Effective Field Theory

    CERN Document Server

    Schäfer, T

    2003-01-01

    We study several issues related to the use of effective field theories in QCD at large baryon density. We show that the power counting is complicated by the appearance of two scales inside loop integrals. Hard dense loops involve the large scale $mu^2$ and lead to phenomena such as screening and damping at the scale $gmu$. Soft loops only involve small scales and lead to superfluidity and non-Fermi liquid behavior at exponentially small scales. Four-fermion operators in the effective theory are suppressed by powers of $1/mu$, but they get enhanced by hard loops. As a consequence their contribution to the pairing gap is only suppressed by powers of the coupling constant, and not powers of $1/mu$. We determine the coefficients of four-fermion operators in the effective theory by matching quark-quark scattering amplitudes. Finally, we introduce a perturbative scheme for computing corrections to the gap parameter in the superfluid phase

  19. 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.

  20. Recent developments in hard X-ray tomography

    CERN Document Server

    Rau, C; Snigirev, A; Schrör, C; Tümmler, J; Lengeler, B

    2001-01-01

    A new technique for magnified hard X-ray tomography using compound refractive lenses (CRLs) has been tested. A full-field X-ray microscope was included into a conventional microtomography setup at a synchrotron undulator beamline. Experiments were carried out at 19.7 keV with a monochromatic beam as well as with the so-called 'pink' beam using a larger energy bandwidth. During this pilot experiment a resolution of about 1 mu m was already achieved, which corresponds to the best resolution obtained with phase-contrast enhanced microtomography. The technique has the potential to increase the spatial resolution of hard-X-ray microtomography to a scale of several hundred nanometers.

  1. Diagnosis Method for Analog Circuit Hard fault and Soft Fault

    Directory of Open Access Journals (Sweden)

    Baoru Han

    2013-09-01

    Full Text Available Because the traditional BP neural network slow convergence speed, easily falling in local minimum and the learning process will appear oscillation phenomena. This paper introduces a tolerance analog circuit hard fault and soft fault diagnosis method based on adaptive learning rate and the additional momentum algorithm BP neural network. Firstly, tolerance analog circuit is simulated by OrCAD / Pspice circuit simulation software, accurately extracts fault waveform data by matlab program automatically. Secondly, using the adaptive learning rate and momentum BP algorithm to train neural network, and then applies it to analog circuit hard fault and soft fault diagnosis. With shorter training time, high precision and global convergence effectively reduces the misjudgment, missing, it can improve the accuracy of fault diagnosis and fast.  

  2. Hard sphere dynamics for normal and granular fluids.

    Science.gov (United States)

    Dufty, James W; Baskaran, Aparna

    2005-06-01

    A fluid of N smooth, hard spheres is considered as a model for normal (elastic collision) and granular (inelastic collision) fluids. The potential energy is discontinuous for hard spheres so that 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 generators for the dynamics of observables and probability densities. The new results presented in the second part refer to applications of these generators to the Liouville dynamics for granular fluids. A set of eigenvalues and eigenfunctions of the generator for this Liouville dynamics system is identified in a special stationary representation. This provides a class of exact solutions to the Liouville equation that are closely related to hydrodynamics for granular fluids.

  3. Determining the Factorizability of Hard Scattering Cross-Sections

    CERN Document Server

    Hornig, Andrew; Ovanesyan, Grigory

    2009-01-01

    The rules of soft-collinear effective theory can be used naively to write hard scattering cross-sections as convolutions of separate hard, jet, and soft functions. We describe an intuitive method to determine, at a given order in perturbation theory, whether these functions are truly infrared safe or not and, thus, whether or not the cross-sections factorize. Using angularity distributions as an illustrative example, we look for regions of integration in the sum of Feynman diagrams contributing to the jet and soft functions where the integrals become infrared divergent. Our analysis is independent of an explicit infrared regulator, and simultaneously clarifies how to distinguish infrared and ultraviolet singularities when pure dimensional regularization is used to regulate both.

  4. 是"hard work",还是"hand work"?

    Institute of Scientific and Technical Information of China (English)

    王维民

    2004-01-01

    @@ 编辑: 贵刊内容丰富,读后思维开阔,受益匪浅.在仔细阅读中发现了一个错误,提出供参考:2004年第2期77页"格言与幽默"中写到 "Surgery is derived from the Latin chirugery meaning hard work……"这里的hard work应为hand work.因为拉丁语chirugery的意思是"用手的工作".故英文"外科"一词的意思应为"用手的工作",而不是"努力工作".

  5. 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.

  6. 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.

  7. ANALYSIS OF CHIP FORMATION DURING HARD TURNING THROUGH ACOUSTIC EMISSION

    Directory of Open Access Journals (Sweden)

    Miroslav Neslušan

    2012-01-01

    Full Text Available The paper deals with analysis of chip formation and related aspects of the chip formation during turning hardened steel 100Cr6. The paper draws a comparison of some aspects of the chip formation between turning annealed and hardened roll bearing steel. The results of the analysis show that there is the formation of a segmented chip in the case of hard turning. Frequency of segmentation is very high. A conventional piezoelectric dynamometer limits the frequency response to about 3.5 kHz. On the other hand, the frequency of process fluctuation may by obtained by using accelerometers or acoustic emission. This paper reports about the dynamic character of cutting process when hard turning and correlation among the calculated segmentation frequencies and the experimental analysis.

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

    Science.gov (United States)

    Loorits, Kristjan

    2014-01-01

    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. PMID:24672510

  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. Injection molded polymeric hard X-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik; Simons, Hugh; Jakobsen, Anders Clemen;

    2015-01-01

    A novel and economical approach for fabricating compound refractive lenses for the purpose of focusing hard X-rays is described. A silicon master was manufactured by UV-lithography and deep reactive ion etching (DRIE). Sacrificial structures were utilized, which enabled accurate control of the et......A novel and economical approach for fabricating compound refractive lenses for the purpose of focusing hard X-rays is described. A silicon master was manufactured by UV-lithography and deep reactive ion etching (DRIE). Sacrificial structures were utilized, which enabled accurate control...... of the etching profile and were removed after DRIE. By electroplating, an inverse nickel sample was obtained, which was used as a mold insert in a commercial polymer injection molding machine. A prototype lens made of polyethylene with a focal length of 350 mm was tested using synchrotron radiation at photon...

  11. 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.

  12. Phonon contribution to the entropy of hard-sphere crystals.

    Science.gov (United States)

    Elser, Veit

    2014-05-01

    Comparing the entropies of hard spheres in the limit of close packing, for different stacking sequences of the hexagonal layers, has been a challenge because the differences are so small. Here we present a method based on a "sticky-sphere" model by which the system interpolates between hard spheres in one limit and a harmonic crystal in the other. For the fcc and hcp stackings we have calculated the entropy difference in the harmonic (sticky) limit, as well as the differences in the free energy change upon removing the stickiness in the model. The former, or phonon entropy, accounts for most of the entropy difference. Our value for the net entropy difference, Δs = 0.001164(8)k(B) per sphere, is in excellent agreement with the best previous estimate by Mau and Huse [Phys. Rev. E 59, 4396 (1999)].

  13. Complex oscillatory yielding of model hard-sphere glasses.

    Science.gov (United States)

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

    2013-04-26

    The yielding behavior 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''. At intermediate frequencies a novel, for hard sphere glasses, double peak in G'' is revealed reflecting both mechanisms. At high frequencies and strain amplitudes a persistent structural anisotropy causes a stress drop within the cycle after strain reversal, while higher stress harmonics are minimized at certain strain amplitudes indicating an apparent harmonic response.

  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. The Multivariate Resultant Is NP-hard in Any Characteristic

    Science.gov (United States)

    Grenet, Bruno; Koiran, Pascal; Portier, Natacha

    The multivariate resultant is a fundamental tool of computational algebraic geometry. It can in particular be used to decide whether a system of n homogeneous equations in n variables is satisfiable (the resultant is a polynomial in the system's coefficients which vanishes if and only if the system is satisfiable). In this paper we present several NP-hardness results for testing whether a multivariate resultant vanishes, or equivalently for deciding whether a square system of homogeneous equations is satisfiable. Our main result is that testing the resultant for zero is NP-hard under deterministic reductions in any characteristic, for systems of low-degree polynomials with coefficients in the ground field (rather than in an extension). We also observe that in characteristic zero, this problem is in the Arthur-Merlin class AM if the generalized Riemann hypothesis holds true. In positive characteristic, the best upper bound remains PSPACE.

  16. Porous Biodegradable Metals for Hard Tissue Scaffolds: A Review

    Directory of Open Access Journals (Sweden)

    A. H. Yusop

    2012-01-01

    Full Text Available Scaffolds have been utilized in tissue regeneration to facilitate the formation and maturation of new tissues or organs where a balance between temporary mechanical support and mass transport (degradation and cell growth is ideally achieved. Polymers have been widely chosen as tissue scaffolding material having a good combination of biodegradability, biocompatibility, and porous structure. Metals that can degrade in physiological environment, namely, biodegradable metals, are proposed as potential materials for hard tissue scaffolding where biodegradable polymers are often considered as having poor mechanical properties. Biodegradable metal scaffolds have showed interesting mechanical property that was close to that of human bone with tailored degradation behaviour. The current promising fabrication technique for making scaffolds, such as computation-aided solid free-form method, can be easily applied to metals. With further optimization in topologically ordered porosity design exploiting material property and fabrication technique, porous biodegradable metals could be the potential materials for making hard tissue scaffolds.

  17. Vickers hardness measurement of ion implanted MgO

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Y. (TRCRE, JAERI, 1233 Watanuki-machi, Takasaki, Gunma 370-12 (Japan)); Rueck, D.M. (Materialforschung, UNILAC, GSI, D-6100, Darmstadt (Germany)); Vogt, D. (Materialforschung, UNILAC, GSI, D-6100, Darmstadt (Germany)); Leible, K. (Materialforschung, UNILAC, GSI, D-6100, Darmstadt (Germany)); Khubeis, I. (University of Jordan, P.O. Box 13097, Amman (Jordan)); Meyer, O. (INFP, KfK, D-7500, Karlsruhe 1 (Germany))

    1994-06-01

    The Vickers hardness was measured for single crystals of MgO(100) implanted with 130 keV or 1.8 MeV Ar[sup +] ions and with 400 keV Xe[sup 2+] ions by means of the indentation technique with an applied load of 0.4-30 mN. Implantation with 130 keV Ar[sup +] and 400 keV Xe[sup 2+] gave similar results in hardening of MgO surface layers. In addition, the dose dependence of the measured hardness curve showed that a softening mechanism takes place at high doses. High energy implantation (1.8 MeV Ar[sup +]) made a hardened surface layer on MgO. This hardened layer also became softer at high doses. ((orig.))

  18. Parametrization of the QCD coupling in Hard and Regge processes

    CERN Document Server

    Ermolaev, B I

    2008-01-01

    We examine the parametrization of the QCD coupling in the Bethe-Salpeter equations for the hard and Regge processes and determine the argument of alpha_s of the factorized gluon. Our analysis shows that for the hard processes alpha_s = alpha_s(k^2_T/(1- beta)) where k^2_T and beta are the longitudinal and transverse moment of the soft parton. On the other hand, in the Regge processes alpha_s = alpha_s(k^2_T}/beta). We have also shown that the well-known parametrization alpha_s = alpha_s(k^2_T) in the DGLAP equations stands only if the lowest integration limit, mu^2, over k^2_T (the starting point of the Q^2 -evolution) obeys the relation mu >> Lambda_{QCD} exp {(\\pi/2)}, otherwise the coupling should be replaced by the more complicated expression.

  19. Influence of Hard Tool Coatings on Process of Stamping

    DEFF Research Database (Denmark)

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

    2007-01-01

    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......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...

  20. 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.

  1. Hard gap in epitaxial semiconductor-superconductor nanowires

    DEFF Research Database (Denmark)

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

    2015-01-01

    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......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...

  2. Dimensional Reduction, Hard Thermal Loops and the Renormalization Group

    CERN Document Server

    Stephens, C R; Hess, P O; Astorga, F; Weber, Axel; Hess, Peter O.; Astorga, Francisco

    2004-01-01

    We study the realization of dimensional reduction and the validity of the hard thermal loop expansion for lambda phi^4 theory at finite temperature, using an environmentally friendly finite-temperature renormalization group with a fiducial temperature as flow parameter. The one-loop renormalization group allows for a consistent description of the system at low and high temperatures, and in particular of the phase transition. The main results are that dimensional reduction applies, apart from a range of temperatures around the phase transition, at high temperatures (compared to the zero temperature mass) only for sufficiently small coupling constants, while the HTL expansion is valid below (and rather far from) the phase transition, and, again, at high temperatures only in the case of sufficiently small coupling constants. We emphasize that close to the critical temperature, physics is completely dominated by thermal fluctuations that are not resummed in the hard thermal loop approach and where universal quant...

  3. Towards an analytical theory for charged hard spheres

    OpenAIRE

    Blum, L.; D.V.P.Veloz

    2007-01-01

    Ion mixtures require an exclusion core to avoid collapse. The Debye Hueckel theory, where ions are point charges, is accurate only in the limit of infinite dilution. The MSA is the embedding of hard cores into DH, is valid for higher densities. In the MSA the properties of any ionic mixture can be represented by a single screening parameter $\\Gamma$. For equal ionic size restricted model is obtained from the Debye parameter $\\kappa$. This one parameter representation (BIMSA) is valid for comp...

  4. 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.

  5. Hard X-ray Sources for the Mexican Synchrotron Project

    Science.gov (United States)

    Reyes-Herrera, Juan

    2016-10-01

    One of the principal tasks for the design of the Mexican synchrotron was to define the storage ring energy. The main criteria for choosing the energy come from studying the electromagnetic spectrum that can be obtained from the synchrotron, because the energy range of the spectrum that can be obtained will determine the applications available to the users of the future light source. Since there is a public demand of hard X-rays for the experiments in the synchrotron community users from Mexico, in this work we studied the emission spectra from some hard X-ray sources which could be the best options for the parameters of the present Mexican synchrotron design. The calculations of the flux and the brightness for one Bending Magnet and four Insertion Devices are presented; specifically, for a Superconducting Bending Magnet (SBM), a Superconducting Wiggler (SCW), an In Vacuum Short Period Undulator (IV-SPU), a Superconducting Undulator (SCU) and for a Cryogenic Permanent Magnet Undulator (CPMU). Two commonly available synchrotron radiation programs were used for the computation (XOP and SRW). From the results, it can be concluded that the particle beam energy from the current design is enough to have one or more sources of hard X-rays. Furthermore, a wide range of hard X-ray region can be covered by the analyzed sources, and the choice of each type should be based on the specific characteristics of the X-ray beam to perform the experiments at the involved beamline. This work was done within the project Fomix Conacyt-Morelos ”Plan Estrategico para la construccion y operación de un Sincrotron en Morelos” (224392).

  6. Phacoemulsification in hard cataracts: the "chop, trip and free" technique

    OpenAIRE

    José Marcos S. Gonçalves

    2004-01-01

    Very hard cataracts continue to be a challenge to phacoemulsification due to the difficulty in breaking the nucleus and also in separating the broken nucleus from the adjacent epinucleus. The present technique is the presentation of a surgical maneuver which uses the Nagahara chopper and the phaco tip to divide the nucleus (including the epinucleus) as a whole and then emulsify it using little time and not very much phaco power.

  7. Development of Hard Elastic Solids from Glassy Polymers.

    Science.gov (United States)

    1980-06-10

    elastic polypropylene (PP) as reported by Park and Noether 5 The stress-strain behavior for three intermittent cycles to 40% extension is shown in Fig. Zb...system. Such viscoelastic effects have been concluded by Park and Noether 1 5 from more extensive stress relaxation investigations of hard elastic PP...Petermann and H. Gleiter, J. Macromol. Sc.- Phys., B12(4), 523 (1976). 4. H. D. Noether , Intern. J. Polymeric Mater.,. 7, 57 (1979). 5. M. E. Mackay

  8. Thermal stability of Al-Cr-N hard coatings

    Energy Technology Data Exchange (ETDEWEB)

    Willmann, H. [Materials Center Leoben, Franz-Josef Strasse 13, 8700 Leoben (Austria) and IFM Material Physics, Division of Thin Film Physics, Linkoeping University, 58183 Linkoeping (Sweden)]. E-mail: herbert.willmann@unileoben.ac.at; Mayrhofer, P.H. [Department of Physical Metallurgy and Materials Testing, University of Leoben, 8700 Leoben (Austria); Materials Chemistry, RWTH-Aachen, 52074 Aachen (Germany); Persson, P.O.A. [IFM Material Physics, Division of Thin Film Physics, Linkoeping University, 58183 Linkoeping (Sweden); FEI Company, 5651 GG Eindhoven (Netherlands); Reiter, A.E. [Balzers Ltd., 9496 Balzers (Liechtenstein); Hultman, L. [IFM Material Physics, Division of Thin Film Physics, Linkoeping University, 58183 Linkoeping (Sweden); Materials Chemistry, RWTH-Aachen, 52074 Aachen (Germany); Mitterer, C. [Department of Physical Metallurgy and Materials Testing, University of Leoben, 8700 Leoben (Austria); Christian Doppler Laboratory for Advanced Hard Coatings, University of Leoben, 8700 Leoben (Austria)

    2006-06-15

    Heat treatment of arc-evaporated cubic Al{sub 0.7}Cr{sub 0.3}N hard coatings in Ar up to 1450 deg. C causes precipitation of AlN. The Cr-enriched matrix transforms into Cr via Cr{sub 2}N under N{sub 2} release. These reactions are investigated by simultaneous thermal analysis, mass spectrometry, X-ray diffraction, and analytical transmission electron microscopy.

  9. Calcium Hardness Analysis of Water Samples Using EDXRF Technique

    Directory of Open Access Journals (Sweden)

    Kanan Deep

    2014-08-01

    Full Text Available Calcium hardness of water samples has been determined using a method based upon the Energy Dispersive X-ray fluorescence (EDXRF technique for elemental analysis. The minimum detection limit for Ca has been found in the range 0.1-100ppm. The experimental approach and analytical method for calcium studies seem satisfactory for the purpose and can be utilized for similar investigations.

  10. Results of endocapsular phacofracture debulking of hard cataracts

    Directory of Open Access Journals (Sweden)

    Davison JA

    2015-07-01

    Full Text Available James A Davison Wolfe Eye Clinic, Marshalltown, IA, USA Purpose/aim of the study: To present a phacoemulsification technique for hard cataracts and compare postoperative results using two different ultrasonic tip motions during quadrant removal.Materials and methods: A phacoemulsification technique which employs in situ fracture and endocapsular debulking for hard cataracts is presented. The prospective study included 56 consecutive cases of hard cataract (LOCS III NC [Lens Opacification Classification System III, nuclear color], average 4.26, which were operated using the Infiniti machine and the Partial Kelman tip. Longitudinal tip movement was used for sculpting for all cases which were randomized to receive longitudinal or torsional/interjected longitudinal (Intelligent Phaco [IP] strategies for quadrant removal. Measurements included cumulative dissipated energy (CDE, 3 months postoperative surgically induced astigmatism (SIA, and corneal endothelial cell density (ECD losses.Results: No complications were recorded in any of the cases. Respective overall and longitudinal vs IP means were as follows: CDE, 51.6±15.6 and 55.7±15.5 vs 48.6±15.1; SIA, 0.36±0.2 D and 0.4±0.2 D vs 0.3±0.2 D; and mean ECD loss, 4.1%±10.8% and 5.9%±13.4% vs 2.7%±7.8%. The differences between longitudinal and IP were not significant for any of the three categories.Conclusion: The endocapsular phacofracture debulking technique is safe and effective for phacoemulsification of hard cataracts using longitudinal or torsional IP strategies for quadrant removal with the Infiniti machine and Partial Kelman tip. Keywords: astigmatism, cataract, corneal endothelium, phacoemulsification, viscoelastic

  11. Frustrated spin model as a hard-sphere liquid.

    Science.gov (United States)

    Mostovoy, M V; Khomskii, D I; Knoester, J; Prokof'ev, N V

    2003-04-11

    We show that one-dimensional topological objects (kinks) are natural degrees of freedom for an antiferromagnetic Ising model on a triangular lattice. Its ground states and the coexistence of spin ordering with an extensive zero-temperature entropy can easily be understood in terms of kinks forming a hard-sphere liquid. Using this picture we explain effects of quantum spin dynamics on that frustrated model, which we also study numerically.

  12. Hard X-ray techniques suitable for polymer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bras, W; Goossens, H; Goderis, B, E-mail: Wim.Bras@esrf.fr [Netherlands Organisation for Scientific Research (NWO) (Netherlands); DUBBLE-ESRF, BP 220, F38043 Grenoble Cedex (France); Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Molecular and Nanomaterials, Chemistry Department, Catholic University of Leuven, Celestijnenlaan 200F (Belgium)

    2010-11-15

    Polymers have been studied since 1979 with 8-12 keV synchrotron radiation X-ray scattering methods and the number and sophistication of the experiments have rapidly grown ever since. More recently, new experimental techniques have been developed that use softer or harder X-rays in less conventional ways. This article provides a brief overview of the possibilities of hard X-ray techniques and indicates some areas that might gain from further developments.

  13. 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...

  14. Direct catalytic asymmetric addition of allyl cyanide to ketones via soft Lewis acid/hard Brønsted base/hard Lewis base catalysis.

    Science.gov (United States)

    Yazaki, Ryo; Kumagai, Naoya; Shibasaki, Masakatsu

    2010-04-21

    We report that a hard Lewis base substantially affects the reaction efficiency of direct catalytic asymmetric gamma-addition of allyl cyanide (1a) to ketones promoted by a soft Lewis acid/hard Brønsted base catalyst. Mechanistic studies have revealed that Cu/(R,R)-Ph-BPE and Li(OC(6)H(4)-p-OMe) serve as a soft Lewis acid and a hard Brønsted base, respectively, allowing for deprotonative activation of 1a as the rate-determining step. A ternary catalytic system comprising a soft Lewis acid/hard Brønsted base and an additional hard Lewis base, in which the basicity of the hard Brønsted base Li(OC(6)H(4)-p-OMe) was enhanced by phosphine oxide (the hard Lewis base) through a hard-hard interaction, outperformed the previously developed binary soft Lewis acid/hard Brønsted base catalytic system, leading to higher yields and enantioselectivities while using one-tenth the catalyst loading and one-fifth the amount of 1a. This second-generation catalyst allows efficient access to highly enantioenriched tertiary alcohols under nearly ideal atom-economical conditions (0.5-1 mol % catalyst loading and a substrate molar ratio of 1:2).

  15. Global Optimal Trajectory in Chaos and NP-Hardness

    Science.gov (United States)

    Latorre, Vittorio; Gao, David Yang

    This paper presents an unconventional theory and method for solving general nonlinear dynamical systems. Instead of the direct iterative methods, the discretized nonlinear system is first formulated as a global optimization problem via the least squares method. A newly developed canonical duality theory shows that this nonconvex minimization problem can be solved deterministically in polynomial time if a global optimality condition is satisfied. The so-called pseudo-chaos produced by linear iterative methods are mainly due to the intrinsic numerical error accumulations. Otherwise, the global optimization problem could be NP-hard and the nonlinear system can be really chaotic. A conjecture is proposed, which reveals the connection between chaos in nonlinear dynamics and NP-hardness in computer science. The methodology and the conjecture are verified by applications to the well-known logistic equation, a forced memristive circuit and the Lorenz system. Computational results show that the canonical duality theory can be used to identify chaotic systems and to obtain realistic global optimal solutions in nonlinear dynamical systems. The method and results presented in this paper should bring some new insights into nonlinear dynamical systems and NP-hardness in computational complexity theory.

  16. Nanoparticle hardness controls the internalization pathway for drug delivery.

    Science.gov (United States)

    Li, Ye; Zhang, Xianren; Cao, Dapeng

    2015-02-14

    Nanoparticle (NP)-based drug delivery systems offer fundamental advantages over current therapeutic agents that commonly display a longer circulation time, lower toxicity, specific targeted release, and greater bioavailability. For successful NP-based drug delivery it is essential that the drug-carrying nanocarriers can be internalized by the target cells and transported to specific sites, and the inefficient internalization of nanocarriers is often one of the major sources for drug resistance. In this work, we use the dissipative particle dynamics simulation to investigate the effect of NP hardness on their internalization efficiency. Three simplified models of NP platforms for drug delivery, including polymeric NP, liposome and solid NP, are designed here to represent increasing nanocarrier hardness. Simulation results indicate that NP hardness controls the internalization pathway for drug delivery. Rigid NPs can enter the cell by a pathway of endocytosis, whereas for soft NPs the endocytosis process can be inhibited or frustrated due to wrapping-induced shape deformation and non-uniform ligand distribution. Instead, soft NPs tend to find one of three penetration pathways to enter the cell membrane via rearranging their hydrophobic and hydrophilic segments. Finally, we show that the interaction between nanocarriers and drug molecules is also essential for effective drug delivery.

  17. Bulk sensitive hard x-ray photoemission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Patt, M., E-mail: m.patt@fz-juelich.de; Wiemann, C. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Weber, N.; Escher, M.; Merkel, M. [Focus GmbH, Neukirchner Str. 2, D-65510 Hünstetten (Germany); Gloskovskii, A.; Drube, W. [DESY Photon Science, Deutsches Elektronen-Synchrotron, D-22603 Hamburg (Germany); Schneider, C. M. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Fakultät f. Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universität Duisburg-Essen, D-47048 Duisburg (Germany)

    2014-11-15

    Hard x-ray photoelectron spectroscopy (HAXPES) has now matured into a well-established technique as a bulk sensitive probe of the electronic structure due to the larger escape depth of the highly energetic electrons. In order to enable HAXPES studies with high lateral resolution, we have set up a dedicated energy-filtered hard x-ray photoemission electron microscope (HAXPEEM) working with electron kinetic energies up to 10 keV. It is based on the NanoESCA design and also preserves the performance of the instrument in the low and medium energy range. In this way, spectromicroscopy can be performed from threshold to hard x-ray photoemission. The high potential of the HAXPEEM approach for the investigation of buried layers and structures has been shown already on a layered and structured SrTiO{sub 3} sample. Here, we present results of experiments with test structures to elaborate the imaging and spectroscopic performance of the instrument and show the capabilities of the method to image bulk properties. Additionally, we introduce a method to determine the effective attenuation length of photoelectrons in a direct photoemission experiment.

  18. Laser-induced autofluorescence of oral cavity hard tissues

    Science.gov (United States)

    Borisova, E. G.; Uzunov, Tz. T.; Avramov, L. A.

    2007-03-01

    In current study oral cavity hard tissues autofluorescence was investigated to obtain more complete picture of their optical properties. As an excitation source nitrogen laser with parameters - 337,1 nm, 14 μJ, 10 Hz (ILGI-503, Russia) was used. In vitro spectra from enamel, dentine, cartilage, spongiosa and cortical part of the periodontal bones were registered using a fiber-optic microspectrometer (PC2000, "Ocean Optics" Inc., USA). Gingival fluorescence was also obtained for comparison of its spectral properties with that of hard oral tissues. Samples are characterized with significant differences of fluorescence properties one to another. It is clearly observed signal from different collagen types and collagen-cross links with maxima at 385, 430 and 480-490 nm. In dentine are observed only two maxima at 440 and 480 nm, related also to collagen structures. In samples of gingival and spongiosa were observed traces of hemoglobin - by its re-absorption at 545 and 575 nm, which distort the fluorescence spectra detected from these anatomic sites. Results, obtained in this study are foreseen to be used for development of algorithms for diagnosis and differentiation of teeth lesions and other problems of oral cavity hard tissues as periodontitis and gingivitis.

  19. COPD: A stepwise or a hit hard approach?

    Science.gov (United States)

    Ferreira, A J; Reis, A; Marçal, N; Pinto, P; Bárbara, C

    2016-01-01

    Current guidelines differ slightly on the recommendations for treatment of Chronic Obstructive Pulmonary Disease (COPD) patients, and although there are some undisputed recommendations, there is still debate regarding the management of COPD. One of the hindrances to deciding which therapeutic approach to choose is late diagnosis or misdiagnosis of COPD. After a proper diagnosis is achieved and severity assessed, the choice between a stepwise or "hit hard" approach has to be made. For GOLD A patients the stepwise approach is recommended, whilst for B, C and D patients this remains debatable. Moreover, in patients for whom inhaled corticosteroids (ICS) are recommended, a step-up or "hit hard" approach with triple therapy will depend on the patient's characteristics and, for patients who are being over-treated with ICS, ICS withdrawal should be performed, in order to optimize therapy and reduce excessive medications. This paper discusses and proposes stepwise, "hit hard", step-up and ICS withdrawal therapeutic approaches for COPD patients based on their GOLD group. We conclude that all approaches have benefits, and only a careful patient selection will determine which approach is better, and which patients will benefit the most from each approach.

  20. The Impact of Hard Disk Firmware Steganography on Computer Forensics

    Directory of Open Access Journals (Sweden)

    Iain Sutherland

    2009-06-01

    Full Text Available The hard disk drive is probably the predominant form of storage media and is a primary data source in a forensic investigation. The majority of available software tools and literature relating to the investigation of the structure and content contained within a hard disk drive concerns the extraction and analysis of evidence from the various file systems which can reside in the user accessible area of the disk. It is known that there are other areas of the hard disk drive which could be used to conceal information, such as the Host Protected Area and the Device Configuration Overlay. There are recommended methods for the detection and forensic analysis of these areas using appropriate tools and techniques. However, there are additional areas of a disk that have currently been overlooked.  The Service Area or Platter Resident Firmware Area is used to store code and control structures responsible for the functionality of the drive and for logging failing or failed sectors.This paper provides an introduction into initial research into the investigation and identification of issues relating to the analysis of the Platter Resident Firmware Area. In particular, the possibility that the Platter Resident Firmware Area could be manipulated and exploited to facilitate a form of steganography, enabling information to be concealed by a user and potentially from a digital forensic investigator.

  1. Mechanics of an Asymmetric Hard-Soft Lamellar Nanomaterial

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Weichao; Fredrickson, Glenn H.; Kramer, Edward J.; Ntaras, Christos; Avgeropoulos, Apostolos; Demassieux, Quentin; Creton, Costantino (UCSB); (Ioannina); (CNRS-UPMC)

    2016-03-24

    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) exhibited kinks and predamaged/damaged grains, as well as cavitation in the soft layers. In contrast, deformation of thick 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.

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

    Directory of Open Access Journals (Sweden)

    BRANISLAV R. SIMONOVIĆ

    2009-05-01

    Full Text Available 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. The adsorption of mineral oil increased as pH values diverged from 7 (neutral. At lower temperatures, the adsorption was notably higher. The wastewater flow rate was adjusted to achieve optimal water purification. Equilibrium was reached after 10 h in static conditions. At that time, more than 99% of mineral oil had been removed. At the beginning of the filtering process, the adsorption rate increased rapidly, only to show a minor decrease afterwards. Equilibrium data were fitted to Freundlich models to determine the water-hard coal partitioning coefficient. Physical adsorption caused by properties of the compounds was the predominant mechanism in the removal process.

  3. Adiabatic Shear Mechanisms for the Hard Cutting Process

    Institute of Scientific and Technical Information of China (English)

    YUE Caixu; WANG Bo; LIU Xianli; FENG Huize; CAI Chunbin

    2015-01-01

    The most important consequence of adiabatic shear phenomenon is formation of sawtooth chip. Lots of scholars focused on the formation mechanism of sawtooth, and the research often depended on experimental approach. For the present, the mechanism of sawtooth chip formation still remalns some ambiguous aspects. This study develops a combined numerical and experimental approach to get deeper understanding of sawtooth chip formation mechanism for Polycrystalline Cubic Boron Nitride (PCBN) tools orthogonal cutting hard steel GCr15. By adopting the Johnson-Cook material constitutive equations, the FEM simulation model established in this research effectively overcomes serious element distortions and cell singularity in high straln domaln caused by large material deformation, and the adiabatic shear phenomenon is simulated successfully. Both the formation mechanism and process of sawtooth are simulated. Also, the change features regarding the cutting force as well as its effects on temperature are studied. More specifically, the contact of sawtooth formation frequency with cutting force fluctuation frequency is established. The cutting force and effect of cutting temperature on mechanism of adiabatic shear are investigated. Furthermore, the effects of the cutting condition on sawtooth chip formation are researched. The researching results show that cutting feed has the most important effect on sawtooth chip formation compared with cutting depth and speed. This research contributes a better understanding of mechanism, feature of chip formation in hard turning process, and supplies theoretical basis for the optimization of hard cutting process parameters.

  4. Practical engineering of hard spin-glass instances

    Science.gov (United States)

    Marshall, Jeffrey; Martin-Mayor, Victor; Hen, Itay

    2016-07-01

    Recent technological developments in the field of experimental quantum annealing have made prototypical annealing optimizers with hundreds of qubits commercially available. The experimental demonstration of a quantum speedup for optimization problems has since then become a coveted, albeit elusive goal. Recent studies have shown that the so far inconclusive results, regarding a quantum enhancement, may have been partly due to the benchmark problems used being unsuitable. In particular, these problems had inherently too simple a structure, allowing for both traditional resources and quantum annealers to solve them with no special efforts. The need therefore has arisen for the generation of harder benchmarks which would hopefully possess the discriminative power to separate classical scaling of performance with size from quantum. We introduce here a practical technique for the engineering of extremely hard spin-glass Ising-type problem instances that does not require "cherry picking" from large ensembles of randomly generated instances. We accomplish this by treating the generation of hard optimization problems itself as an optimization problem, for which we offer a heuristic algorithm that solves it. We demonstrate the genuine thermal hardness of our generated instances by examining them thermodynamically and analyzing their energy landscapes, as well as by testing the performance of various state-of-the-art algorithms on them. We argue that a proper characterization of the generated instances offers a practical, efficient way to properly benchmark experimental quantum annealers, as well as any other optimization algorithm.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S., E-mail: susanne.kuehn@cern.ch

    2016-07-11

    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. - Highlights: • The RD50 Collaboration is a CERN R&D collaboration dedicated to the development of radiation hard silicon devices for high luminosity collider experiments. • The collaboration investigates defect, material and detector characterization, the development of new structures and full detector systems. • Results of measured data of n-in-p type sensors allow recommendations for silicon tracking detectors at the HL-LHC. • The charge multiplication effect was investigated to allow its exploitation and resulted in new structures like LGAD sensors. • New sensor types like slim and active edge sensors, 3D detectors, and lately HVCMOS devices were developed in the active collaboration.

  6. Birhythmicity and Hard Excitation from Coupled Synthetic Feedback Loops

    Directory of Open Access Journals (Sweden)

    Aimin Chen

    2014-01-01

    Full Text Available Synthetic biology opens up the possibility of creating circuits that would not survive in the natural world and studying their behaviors in living cells, expanding our notion of biology. Based on this, we analyze on a synthetic biological system the effect of coupling between two instability-generating mechanisms. The systems considered are two topologically equivalent synthetic networks. In addition to simple periodic oscillations and stable steady state, the system can exhibit a variety of new modes of dynamic behavior: coexistence between two stable periodic regimes (birhythmicity and coexistence of a stable periodic regime with a stable steady state (hard excitation. Birhythmicity and hard excitation have been proved to exist in biochemical networks. Through bifurcation analysis on these two synthetic cellular networks, we analyze the function of network structure for the collapse and revival of birhythmicity and hard excitation with the variation of parameters. The results have illustrated that the bifurcation space can be divided into four subspaces for which the dynamical behaviors of the system are generically distinct. Our analysis corroborates the results obtained by numerical simulation of the dynamics.

  7. Dentinogenesis imperfecta - hardness and Young's modulus of teeth.

    Science.gov (United States)

    Wieczorek, Aneta; Loster, Jolanta; Ryniewicz, Wojciech; Ryniewicz, Anna M

    2013-01-01

    Dentinogenesis imperfecta type II (DI-II) is the most common dental genetic disease with reported incidence 1 in 8000. Elasticity and hardness of the enamel of teeth are important values which are connected with their resistance to attrition. It is hypothesized that values of physical properties for healthy teeth and teeth with DI-II are different. The aim of the study was to investigate some physical properties of teeth extracted from patients with DI-II in comparison with normal teeth. The material of the study was six teeth: three lower molars, with clinical signs of DI-II, which were extracted due to complications of pulp inflammation and three other lower molars which were extracted for orthodontic reasons - well formed, without any signs of pathology. The surfaces of DI-II and normal teeth were tested on the CSM Instruments Scratch Tester machine (producer CSEM Switzerland) by Oliver and Pharr method. The indenter used was Vicker's VG-73 diamond indenter. Additionally, the Scanning Electron Microscopy (SEM) analysis of the surface of the teeth with DI-II was made. Vickers hardness of the teeth with dental pathology (DI-II) was seven times smaller, and Young's modulus six times smaller than those of healthy teeth. The parameters of hardness and elasticity of enamel of teeth with clinical diagnosis of DI-II were very much smaller than in normal teeth and because of that can be responsible for attrition.

  8. Peripheral radial chop technique for phacoemulsification of hard cataracts

    Institute of Scientific and Technical Information of China (English)

    LI Shao-wei; XIE Li-xin; SONG Zhen-hua; MENG Li; JIANG Jian

    2007-01-01

    Background Phacoemulsification yields successful outcomes in eyes with standard cataract. Though techniques have been improved, it is still challenging to perform phacoemulsification in cases of hard cataracts for difficulty in nuclear management and much more complications. This study aimed at describing and evaluating the efficacy and safety of a peripheral radial chop technique to remove hard cataracts.Methods In this prospective study conducted between January 2003 and January 2004, 107 consecutive eyes with hard cataract underwent modified phacoemulsification surgery with peripheral radial chop technique by the Bausch & Lomb Millennium phacoemulsifier with preset parameters of power less than 30%; vaccum, 150 mmHg; and bottle height,85 cm when a DP8145 phaco tip was used, and vaccum, 380 mmHg; bottle height, 95 cm when a DP8245 phaco tip was used.Results The mean ultrasonic power was 14.7% (range 9% to 19%), ultrasonic time was 1.98 minutes (range 1.55 to 3.18 minutes). At 1, 7 and 30 days postoperatively, the eyes with uncorrected visual acuity 0.5 or better accounted for 76.42%, 87.16% and 90.67% respectively. At 1 month, the endothelial cell loss rate was 9.74% (range 8% to 17%). There were 6 cases of posterior capsule rupture in an early period of study. No serious intraoperative or postoperative complications were noted.Conclusions The peripheral radial chop technique was effective without serious complications in hands of an experienced surgeon.

  9. Investigating hard sphere interactions through spin echo scattering angle measurement

    Science.gov (United States)

    Washington, Adam

    Spin Echo Scattering Angle Measurement (SESAME) allows neutron scattering instruments to perform real space measurements on large micron scale samples by encoding the scattering angle into the neutron's spin state via Larmor precession. I have built a SESAME instrument at the Low Energy Neutron Source. I have also assisted in the construction of a modular SESAME instrument on the ASTERIX beamline at Los Alamos National lab. The ability to tune these instruments has been proved mathematically and optimized and automated experimentally. Practical limits of the SESAME technique with respect to polarization analyzers, neutron spectra, Larmor elements, and data analysis were investigated. The SESAME technique was used to examine the interaction of hard spheres under depletion. Poly(methyl methacrylate) spheres suspended in decalin had previously been studied as a hard sphere solution. The interparticle correlations between the spheres were found to match the Percus-Yevick closure, as had been previously seen in dynamical light scattering experiments. To expand beyond pure hard spheres, 900kDa polystyrene was added to the solution in concentrations of less than 1% by mass. The steric effects of the polystyrene were expected to produce a short-range, attractive, "sticky" potential. Experiment showed, however, that the "sticky" potential was not a stable state and that the spheres would eventually form long range aggregates.

  10. Hard X-ray emission of Sco X-1

    CERN Document Server

    Revnivtsev, Mikhail G; Churazov, Eugene M; Krivonos, Roman A

    2014-01-01

    We study hard X-ray emission of the brightest accreting neutron star Sco X-1 with INTEGRAL observatory. Up to now INTEGRAL have collected ~4 Msec of deadtime corrected exposure on this source. We show that hard X-ray tail in time average spectrum of Sco X-1 has a power law shape without cutoff up to energies ~200-300 keV. An absence of the high energy cutoff does not agree with the predictions of a model, in which the tail is formed as a result of Comptonization of soft seed photons on bulk motion of matter near the compact object. The amplitude of the tail varies with time with factor more than ten with the faintest tail at the top of the so-called flaring branch of its color-color diagram. We show that the minimal amplitude of the power law tail is recorded when the component, corresponding to the innermost part of optically thick accretion disk, disappears from the emission spectrum. Therefore we show that the presence of the hard X-ray tail may be related with the existence of the inner part of the optica...

  11. Passive and active microrheology of hard-sphere colloids.

    Science.gov (United States)

    Wilson, L G; Harrison, A W; Schofield, A B; Arlt, J; Poon, W C K

    2009-03-26

    We performed passive and active microrheology using probe particles in a bath of well-characterized, model hard-sphere colloids in the fluid state over the whole range of volume fractions below the glass transition. The probe and bath particles have nearly the same size. Passive tracking of probe particles yields short-time self-diffusion coefficients. Comparison with literature data demonstrates that the interaction between probe and bath particles is hard-sphere-like. The short-time diffusivities yield one set of microviscosities as a function of volume fraction, which agrees with previous macrorheological measurements of the high-frequency viscosity of hard-sphere colloids. Using optical tweezers, we measure the force on a trapped probe particle as the rest of the sample is translated at constant velocity. This yields a second set of microviscosities at high Péclet numbers. These agree with previous macrorheological measurements of the high-shear viscosity of similar colloids, at shear-rates below the onset of shear-thickening.

  12. Improved model for mixtures of polymers and hard spheres

    Science.gov (United States)

    D'Adamo, Giuseppe; Pelissetto, Andrea

    2016-12-01

    Extensive Monte Carlo simulations are used to investigate how model systems of mixtures of polymers and hard spheres approach the scaling limit. We represent polymers as lattice random walks of length L with an energy penalty w for each intersection (Domb-Joyce model), interacting with hard spheres of radius R c via a hard-core pair potential of range {{R}\\text{mon}}+{{R}c} , where R mon is identified as the monomer radius. We show that the mixed polymer-colloid interaction gives rise to new confluent corrections. The leading ones scale as {{L}-ν} , where ν ≈ 0.588 is the usual Flory exponent. Finally, we determine optimal values of the model parameters w and R mon that guarantee the absence of the two leading confluent corrections. This improved model shows a significantly faster convergence to the asymptotic limit L\\to ∞ and is amenable for extensive and accurate numerical simulations at finite density, with only a limited computational effort.

  13. Young's modulus and hardness of shark tooth biomaterials.

    Science.gov (United States)

    Whitenack, Lisa B; Simkins, Daniel C; Motta, Philip J; Hirai, Makoto; Kumar, Ashok

    2010-03-01

    To date, the majority of studies on feeding mechanics in sharks have focused on the movement of cranial components and muscle function, with little attention to tooth properties or function. Attributes related to mechanical properties, such as structural strength, may also be subjected to natural selection. Additionally it is necessary to characterize these properties in order to construct biomechanical models of tooth function. The goal of this study was to determine hardness and elastic modulus for the shark tooth materials enameloid, osteodentine, and orthodentine. Five teeth each from one carcharhiniform species, the bonnethead Sphyrna tiburo, and one lamniform, the sand tiger shark Carcharias taurus, were utilized for nanoindentation testing. Each tooth was sectioned transversely, air-dried, and polished. Both enameloid and dentine were tested on each tooth via a Berkovich diamond tip, with nine 2 microm deep indentations per material. t-Tests were used to determine if there were differences in hardness and Young's modulus between the tooth materials of the two species. There was no significant difference between the two species for the material properties of enameloid, however both hardness and Young's modulus were higher for osteodentine than for orthodentine. This may be due to differences in microanatomy and chemical composition, however this needs to be studied in greater detail.

  14. Hard x-ray imaging polarimeter for PolariS

    Science.gov (United States)

    Hayashida, Kiyoshi; Kim, Juyong; Sadamoto, Masaaki; Yoshinaga, Keigo; Gunji, Shuichi; Mihara, Tatehiro; Kishimoto, Yuji; Kubo, Hidetoshi; Mizuno, Tsunefumi; Takahashi, Hiromitsu; Dotani, Tadayasu; Yonetoku, Daisuke; Nakamori, Takeshi; Yoneyama, Tomokage; Ikeyama, Yuki; Kamitsukasa, Fumiyoshi

    2016-07-01

    Hard X-ray imaging polarimeters are developed for the X-ray γ-ray polaeimtery satellite PolariS. The imaging polarimter is scattering type, in which anisotropy in the direction of Compton scattering is employed to measure the hard X-ray (10-80 keV) polarization, and is installed on the focal planes of hard X-ray telescopes. We have updated the design of the model so as to cover larger solid angles of scattering direction. We also examine the event selection algorithm to optimize the detection efficiency of recoiled electrons in plastic scintillators. We succeed in improving the efficiency by factor of about 3-4 from the previous algorithm and criteria for 18-30 keV incidence. For 23 keV X-ray incidence, the recoiled electron energy is about 1 keV. We measured the efficiency to detect recoiled electrons in this case, and found about half of the theoretical limit. The improvement in this efficiency directly leads to that in the detection efficiency. In other words, however, there is still a room for improvement. We examine various process in the detector, and estimate the major loss is primarily that of scintillation light in a plastic scintillator pillar with a very small cross section (2.68mm squared) and a long length (40mm). Nevertheless, the current model provides the MDP of 6% for 10mCrab sources, which are the targets of PolariS.

  15. It must be hard to stay so close

    CERN Multimedia

    Rossi, L

    The ATLAS pixel detector should operate for many years at a few centimeters from the LHC collision region. Every part of the detector should then be radiation hard to levels exceeding 500 KGy. This requirement is particularly difficult to meet for the active parts of the detectors, namely the sensors and the electronics. While the pixel sensors have already proven to be rad-hard, the electronics, being more complex, have required a longer development period. It is then with understandable excitement that the pixel collaboration begun to test the first samples of rad-hard electronics developed in Deep Sub Micron (DSM), a technology where the very pure and thin oxides minimize the transistor voltage threshold variation with irradiation. The first DSM 8" wafers have been delivered in January 2002, after a long and intense design activity lead by Kevin Einsweiler. Several laboratories did contribute to the design of the electronics: the Front End chip has been developed by Bonn, CPPM and LBNL, the Module Contro...

  16. Hard X-ray Observations of Magnetic Cataclysmic Variables

    CERN Document Server

    Singh, K P; Mukerjee, K; Barrett, P; Schlegel, E M

    2003-01-01

    Hard X-ray light curves and spectral parameters from our analysis of X-ray data of five AM Her type systems - V2301 Oph, V1432 Aql, EP Draconis, GG Leonis, V834 Cen, and one intermediate polar - TV Col, observed using the Rossi X-ray Timing Explorer satellite are presented. A new improved ephemeris has been derived for V2301 Oph using the mid-eclipse timings. Average intensity variations, without any change of shape of the light curve or hardness ratio, are observed on timescales of a few days to a few months in V2301 Oph. V1432 Aql shows erratic variations on a timescale of a day, at least 2 sharp dips near orbital phases 0.35 and 0.5, and a total eclipse. Hard X-ray eclipses are also reported in EP Dra and GG Leo. V834 Cen shows intensity variations on yearly timescale and is found to be in a low state in 2002. In TV Col, a binary orbital modulation at 5.5h, in addition to the spin period of 1910s, is reported for the first time. Maximum spectral temperatures in Polars have been determined and used to estim...

  17. CO II laser free-form processing of hard tissue

    Science.gov (United States)

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

    2007-07-01

    Drilling and surface processing of bone and tooth tissue belongs to standard medical procedures (bores and embeddings for implants, trepanation etc.). Small circular bores can be generally quickly produced with mechanical drills. However problems arise at angled drilling, the need to execute drilling procedures without damaging of sensitive soft tissue structures underneath the bone or the attempt to mill small non-circular cavities in hard tissue with high precision. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The processing of bone is done with a CO II laser (10.6 μm) with pulse durations of 50 - 100 μs, combined with a PC-controlled fast galvanic laser beam scanner and a fine water-spray, which helps keeping the ablation process effective and without thermal side-effects. Laser "milling" of non-circular cavities with 1 - 4 mm width and about 10 mm depth can be especially interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser processing of these cavities without thermal damage and with minimised tapering. It included the exploration of different filling patterns (concentric rings, crosshatch, parallel lines, etc.), definition of maximal pulse duration, repetition rate and laser power, and optimal water spray position. The optimised results give evidence for the applicability of pulsed CO II lasers for biologically tolerable effective processing of deep cavities in hard tissue.

  18. Dough rheology and wet milling of hard waxy wheat flours.

    Science.gov (United States)

    Guan, Lan; Seib, Paul A; Graybosch, Robert A; Bean, Scott; Shi, Yong-Cheng

    2009-08-12

    To realize the full potential of waxy wheat (Triticum aestivum L.), the wet milling properties of waxy wheat flours including their dough-mixing properties were investigated. Flours of six waxy hard wheats, one normal hard wheat ('Karl 92'), and one partial waxy hard wheat ('Trego') were fractionated by the dough-washing (Martin) process, and the yields and recoveries of starch and gluten were compared. When waxy and normal wheat starches each were blended with a wheat gluten to give a mixture containing 14.5% protein, they gave very different mixograms even though the protein was the same in those blends. Waxy wheat starch absorbed more water than normal wheat starch, which apparently retarded hydration of gluten and dough development. Higher water content had to be used for some waxy wheat flours to develop optimum dough. Washing waxy wheat flour dough under a stream of water caused dough to become slack, spread out more on the sieve, and break apart into several pieces, which when thoroughly washed, coalesced into an elastic dough like the controls. By mixing a weak dough with 2% NaCl solution or by adding hemicellulase, stickiness of the dough subsided during the washing step and thereby improved the recovery of the gluten and starch fractions.

  19. Discovery of Superconductivity in Hard Hexagonal ε-NbN.

    Science.gov (United States)

    Zou, Yongtao; Qi, Xintong; Zhang, Cheng; Ma, Shuailing; Zhang, Wei; Li, Ying; Chen, Ting; Wang, Xuebing; Chen, Zhiqiang; Welch, David; Zhu, Pinwen; Liu, Bingbing; Li, Qiang; Cui, Tian; Li, Baosheng

    2016-02-29

    Since the discovery of superconductivity in boron-doped diamond with a critical temperature (TC) near 4 K, great interest has been attracted in hard superconductors such as transition-metal nitrides and carbides. Here we report the new discovery of superconductivity in polycrystalline hexagonal ε-NbN synthesized at high pressure and high temperature. Direct magnetization and electrical resistivity measurements demonstrate that the superconductivity in bulk polycrystalline hexagonal ε-NbN is below ∼11.6 K, which is significantly higher than that for boron-doped diamond. The nature of superconductivity in hexagonal ε-NbN and the physical mechanism for the relatively lower TC have been addressed by the weaker bonding in the Nb-N network, the co-planarity of Nb-N layer as well as its relatively weaker electron-phonon coupling, as compared with the cubic δ-NbN counterpart. Moreover, the newly discovered ε-NbN superconductor remains stable at pressures up to ∼20 GPa and is significantly harder than cubic δ-NbN; it is as hard as sapphire, ultra-incompressible and has a high shear rigidity of 201 GPa to rival hard/superhard material γ-B (∼227 GPa). This exploration opens a new class of highly desirable materials combining the outstanding mechanical/elastic properties with superconductivity, which may be particularly attractive for its technological and engineering applications in extreme environments.

  20. Hard X-ray mirrors for Nuclear Security

    Energy Technology Data Exchange (ETDEWEB)

    Descalle, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brejnholt, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hill, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alameda, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soufli, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pivovaroff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pardini, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-07

    Research performed under this LDRD aimed to demonstrate the ability to detect and measure hard X-ray emissions using multilayer X-ray reflective optics above 400 keV, to enable the development of inexpensive and high-accuracy mirror substrates, and to investigate applications of hard X-ray mirrors of interest to the nuclear security community. Experiments conducted at the European Synchrotron Radiation Facility demonstrated hard X-ray mirror reflectivity up to 650 keV for the first time. Hard X-ray optics substrates must have surface roughness under 3 to 4 Angstrom rms, and three materials were evaluated as potential substrates: polycarbonates, thin Schott glass and a new type of flexible glass called Willow Glass®. Chemical smoothing and thermal heating of the surface of polycarbonate samples, which are inexpensive but have poor intrinsic surface characteristics, did not yield acceptable surface roughness. D263 Schott glass was used for the focusing optics of the NASA NuSTAR telescope. The required specialized hardware and process were costly and motivated experiments with a modified non-contact slumping technique. The surface roughness of the glass was preserved and the process yielded cylindrical shells with good net shape pointing to the potential advantage of this technique. Finally, measured surface roughness of 200 and 130 μm thick Willow Glass sheets was between 2 and 2.5 A rms. Additional results of flexibility tests and multilayer deposition campaigns indicated it is a promising substrate for hard X-ray optics. The detection of U and Pu characteristics X-ray lines and gamma emission lines in a high background environment was identified as an area for which X-ray mirrors could have an impact and where focusing optics could help reduce signal to noise ratio by focusing signal onto a smaller detector. Hence the first one twelvetant of a Wolter I focusing optics for the 90 to 140 keV energy range based on aperiodic multilayer coating was designed. Finally

  1. Efficiency of rejection-free dynamic Monte Carlo methods for homogeneous spin models, hard disk systems, and hard sphere systems.

    Science.gov (United States)

    Watanabe, Hiroshi; Yukawa, Satoshi; Novotny, M A; Ito, Nobuyasu

    2006-08-01

    We construct asymptotic arguments for the relative efficiency of rejection-free Monte Carlo (MC) methods compared to the standard MC method. We find that the efficiency is proportional to exp(constbeta) in the Ising, sqrt[beta] in the classical XY, and beta in the classical Heisenberg spin systems with inverse temperature beta, regardless of the dimension. The efficiency in hard particle systems is also obtained, and found to be proportional to (rho(cp)-rho)(-d) with the closest packing density rho(cp), density rho, and dimension d of the systems. We construct and implement a rejection-free Monte Carlo method for the hard-disk system. The RFMC has a greater computational efficiency at high densities, and the density dependence of the efficiency is as predicted by our arguments.

  2. Friction and hardness of gold films deposited by ion plating and evaporation

    Science.gov (United States)

    Miyoshi, K.; Spalvins, T.; Buckley, D. H.

    1983-01-01

    Sliding friction experiments were conducted with ion-plated and vapor-deposited gold films on various substrates in contact with a 0.025-mm-radius spherical silicon carbide rider in mineral oil. Hardness measurements were also made to examine the hardness depth profile of the coated gold on the substrate. The results indicate that the hardness is influenced by the depth of the gold coating from the surface. The hardness increases with an increase in the depth. The hardness is also related to the composition gradient in the graded interface between the gold coating and the substrate. The graded interface exhibited the highest hardness resulting from an alloy hardening effect. The coefficient of friction is inversely related to the hardness, namely, the load carrying capacity of the surface. The greater the hardness that the metal surface possesses, the lower is the coefficient of friction. The graded interface exhibited the lowest coefficient of friction.

  3. 76 FR 10403 - Western Digital Technologies, Inc., Coporate Headquaters/Hard Drive Development Division, Lake...

    Science.gov (United States)

    2011-02-24

    ... Drive Development Division, Lake Forest, California (Western Digital Technologies). The Department's... former workers of Western Digital Technologies, Inc., Corporate Headquarters/Hard Drive Development... Employment and Training Administration Western Digital Technologies, Inc., Coporate Headquaters/Hard...

  4. High-Performance, Radiation-Hard, 2-D, Near-Infrared, Avalanche Photodiode Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this STTR project we will address the radiation hardness issues using radiation hard (RH) materials. We will based on the RH material to develop our photon...

  5. Dependence of Hardness of Silicate Glasses on Composition and Thermal History

    DEFF Research Database (Denmark)

    Jensen, Martin; Smedskjær, Morten Mattrup; Yue, Yuanzheng

    composition on hardness of silicate glasses. E-glasses of different compositions are subjected to various degrees of annealing to obtain various fictive temperatures in the glasses. It is found that hardness decreases with the fictive temperature. Addition of Na2O to a SiO2-Al2O3-Na2O glass system causes......The prediction of hardness is possible for crystalline materials, but so far not possible for glasses. In this work, several important factors that should be used for predicting the hardness of glasses are discussed. To do so, we have studied the influences of thermal history and chemical...... a decrease in hardness. However, hardness cannot solely be determined from the degree of polymerisation of the glass network. It is also determined by the effect of ionic radius on hardness. However, this effect has opposite trend for alkali and alkaline earth ions. The hardness increases with ionic radius...

  6. Communication Considerations for Parents of Deaf and Hard-of-Hearing Children

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Communication Considerations for Parents of Deaf and Hard-of- ... people have debated the best ways to develop communication skills and provide education for deaf and hard- ...

  7. Thermodynamic model of hardness: Particular case of boron-rich solids

    OpenAIRE

    Mukhanov, V. A.; Kurakevych, O. O.; Solozhenko, V. L.

    2011-01-01

    A number of successful theoretical models of hardness have been developed recently. A thermodynamic model of hardness, which supposes the intrinsic character of correlation between hardness and thermodynamic properties of solids, allows one to predict hardness of known or even hypothetical solids from the data on Gibbs energy of atomization of the elements, which implicitly determine the energy density per chemical bonding. The only structural data needed is the coordination number of the ato...

  8. Comparison of time-dependent changes in the surface hardness of different composite resins

    OpenAIRE

    Ozcan, Suat; Yikilgan, Ihsan; Uctasli, Mine Betul; Bala, Oya; Kurklu, Zeliha Gonca Bek

    2013-01-01

    Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker's hardness tester. The samples wer...

  9. Tunable long range forces mediated by self-propelled colloidal hard spheres

    NARCIS (Netherlands)

    Ni, R.; Cohen Stuart, M.A.; Bolhuis, P.G.

    2015-01-01

    Using Brownian dynamics simulations, we systematically study the effective interaction between two parallel hard walls in a 2D suspension of self-propelled (active) colloidal hard spheres, and we find that the effective force between two hard walls can be tuned from a long range repulsion into a lon

  10. Impact of CMOS Scaling on Single-Event Hard Errors in Space Systems

    Science.gov (United States)

    Johnston, A. H.; Swift, G. M.; Shaw, D. C.

    1995-01-01

    Applications of highly scaled devices in space applications are shown to be limited by hard errors from cosmic rays. Hard errors were first observed in 0.8 (micro)m DRAMs. For feature sizes below 0.5 (micro)m, scaling theory predicts that low power devices will have much lower hard error rates than devices optimized for high speed.

  11. Hard Sludge Formation in Modern Steam Generators of Nuclear Power Plants Formation, Risks and Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Strohmer, F.

    2013-07-01

    This article will discuss the physical and chemical reasons for the increased tendency to form hard sludge on the secondary side of modern nuclear steam generators (SG). The mechanism of hard sludge induced denting will be explained. Moreover, advice on operation and maintenance to mitigate hard sludge formation and denting damages will be presented.

  12. Improved discrimination of soft and hard white wheat using SKCS and imaging parameters

    Science.gov (United States)

    Natural variation in the hardness of wheat kernels often results in an overlap between hard and soft classes in the distribution of hardness indices (HI) as measured with the single kernel characterization system (SKCS) and is a major contributor to classification errors. This is particularly true f...

  13. Development and Study of Hard-Facing Materials on the Base of Heat-Resisting High-Hardness Steels for Plasma-Jet Hard- Facing in Shielding-Doping Nitrogen Atmosphere

    Science.gov (United States)

    Malushin, N. N.; Kovalev, A. P.; Valuev, D. V.; Shats, E. A.; Borovikov, I. F.

    2016-08-01

    The authors develop hard-facing materials on the base of heat-resisting highhardness steels for plasma-jet hard-facing in nitrogen atmosphere for manufacturing parts of mining and metallurgic equipment which significantly simplify the production process and effect a saving when producing bimetallic parts and tools.

  14. Investigation of ultrashort-pulsed laser on dental hard tissue

    Science.gov (United States)

    Uchizono, Takeyuki; Awazu, Kunio; Igarashi, Akihiro; Kato, Junji; Hirai, Yoshito

    2007-02-01

    Ultrashort-pulsed laser (USPL) can ablate various materials with precious less thermal effect. In laser dentistry, to solve the problem that were the generation of crack and carbonized layer by irradiating with conventional laser such as Er:YAG and CO II laser, USPL has been studied to ablate dental hard tissues by several researchers. We investigated the effectiveness of ablation on dental hard tissues by USPL. In this study, Ti:sapphire laser as USPL was used. The laser parameter had the pulse duration of 130 fsec, 800nm wavelength, 1KHz of repetition rate and the average power density of 90~360W/cm2. Bovine root dentin plates and crown enamel plates were irradiated with USPL at 1mm/sec using moving stage. The irradiated samples were analyzed by SEM, EDX, FTIR and roughness meter. In all irradiated samples, the cavity margin and wall were sharp and steep, extremely. In irradiated dentin samples, the surface showed the opened dentin tubules and no smear layer. The Ca/P ratio by EDX measurement and the optical spectrum by FTIR measurement had no change on comparison irradiated samples and non-irradiated samples. These results confirmed that USPL could ablate dental hard tissue, precisely and non-thermally. In addition, the ablation depths of samples were 10μm, 20μm, and 60μm at 90 W/cm2, 180 W/cm2, and 360 W/cm2, approximately. Therefore, ablation depth by USPL depends on the average power density. USPL has the possibility that can control the precision and non-thermal ablation with depth direction by adjusting the irradiated average power density.

  15. Effects of Organogel Hardness and Formulation on Acceptance of Frankfurters.

    Science.gov (United States)

    Barbut, S; Wood, J; Marangoni, A G

    2016-09-01

    Different organogel formulations used as beef fat (BF) replacement (0%, 20%, 40%, 60%, and 80%) were utilized to optimize the mechanical properties of frankfurters. Organogels, made of canola oil (CO), included different concentrations of ethyl cellulose (EC) and sorbitan monostearate (SMS). They consisted of: 8% EC + 1.5% SMS referred to as organogel-I (OG-I), 8% EC + 3.0% SMS (OG-II), and 10% EC + 1.5% SMS (OG-III), which were found promising in a previous study when used at 100% replacement. Replacement of BF with organogels at all levels could bring down the very high hardness values (texture profile analysis and sensory) of frankfurters prepared using CO by itself, relative to the BF control. OG-I and OG-II quantity had no significant effect on hardness and springiness, being similar in many cases to the BF and lower than the CO control. Shear force values of all organogel treatments were not significantly different from one another, and were between the BF and CO controls. Smokehouse yield showed a pattern of decreasing losses with increasing organogel replacement level. Sensory analysis revealed that using CO by itself significantly increased hardness, but structuring the oil (via organogelation), brought it down to the BF control value in all OG-I and OG-II formulations. Juiciness was significantly reduced by using liquid oil but increased with raising the amount of organogels. Oiliness sensation increased with higher organogel substitution and was actually higher than the beef control. The study demonstrates the potential use of vegetable oil structuring in replacing the more saturated BF in emulsion-type meat products.

  16. Modelling of nuclear explosions in hard rock sites

    Energy Technology Data Exchange (ETDEWEB)

    Brunish, W.M.; App, F.N.

    1993-05-01

    This study represents part of a larger effort to systematically model the effects of differing source region properties on ground motion from underground nuclear explosions at the Nevada Test Site. In previous work by the authors the primary emphasis was on alluvium and both saturated and unsaturated tuff. We have attempted to model events on Pahute Mesa, where either the working point medium, or some of the layers above the working point, or both, are hard rock. The complex layering at these sites, however, has prevented us from drawing unambiguous conclusions about modelling hard rock. In order to learn more about the response of hard rock to underground nuclear explosions, we have attempted to model the PILEDRIVER event. PILEDRIVER was fired on June 2, 1966 in the granite stock of Area 15 at the Nevada Test Site. The working point was at a depth of 462.7 m and the yield was determined to be 61 kt. Numerous surface, sub-surface and free-field measurements were made and analyzed by SRI. An attempt was made to determine the contribution of spall to the teleseismic signal, but proved unsuccessful because most of the data from below-shot-level gauges was lost. Nonetheless, there is quite a bit of good quality data from a variety of locations. We have been able to obtain relatively good agreement with the experimental PILEDRIVER waveforms. In order to do so, we had to model the granodiorite as being considerably weaker than ``good quality`` granite, and it had to undergo considerable weakening due to shock damage as well. In addition, the near-surface layers had to be modeled as being weak and compressible and as have a much lower sound speed than the material at depth. The is consistent with a fractured and jointed material at depth, and a weathered material near the surface.

  17. Modelling of nuclear explosions in hard rock sites

    Energy Technology Data Exchange (ETDEWEB)

    Brunish, W.M.; App, F.N.

    1993-01-01

    This study represents part of a larger effort to systematically model the effects of differing source region properties on ground motion from underground nuclear explosions at the Nevada Test Site. In previous work by the authors the primary emphasis was on alluvium and both saturated and unsaturated tuff. We have attempted to model events on Pahute Mesa, where either the working point medium, or some of the layers above the working point, or both, are hard rock. The complex layering at these sites, however, has prevented us from drawing unambiguous conclusions about modelling hard rock. In order to learn more about the response of hard rock to underground nuclear explosions, we have attempted to model the PILEDRIVER event. PILEDRIVER was fired on June 2, 1966 in the granite stock of Area 15 at the Nevada Test Site. The working point was at a depth of 462.7 m and the yield was determined to be 61 kt. Numerous surface, sub-surface and free-field measurements were made and analyzed by SRI. An attempt was made to determine the contribution of spall to the teleseismic signal, but proved unsuccessful because most of the data from below-shot-level gauges was lost. Nonetheless, there is quite a bit of good quality data from a variety of locations. We have been able to obtain relatively good agreement with the experimental PILEDRIVER waveforms. In order to do so, we had to model the granodiorite as being considerably weaker than good quality'' granite, and it had to undergo considerable weakening due to shock damage as well. In addition, the near-surface layers had to be modeled as being weak and compressible and as have a much lower sound speed than the material at depth. The is consistent with a fractured and jointed material at depth, and a weathered material near the surface.

  18. An approach for addressing hard-to-detect hot spots.

    Science.gov (United States)

    Abelquist, Eric W; King, David A; Miller, Laurence F; Viars, James A

    2013-05-01

    The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) survey approach is comprised of systematic random sampling coupled with radiation scanning to assess acceptability of potential hot spots. Hot spot identification for some radionuclides may not be possible due to the very weak gamma or x-ray radiation they emit-these hard-to-detect nuclides are unlikely to be identified by field scans. Similarly, scanning technology is not yet available for chemical contamination. For both hard-to-detect nuclides and chemical contamination, hot spots are only identified via volumetric sampling. The remedial investigation and cleanup of sites under the Comprehensive Environmental Response, Compensation, and Liability Act typically includes the collection of samples over relatively large exposure units, and concentration limits are applied assuming the contamination is more or less uniformly distributed. However, data collected from contaminated sites demonstrate contamination is often highly localized. These highly localized areas, or hot spots, will only be identified if sample densities are high or if the environmental characterization program happens to sample directly from the hot spot footprint. This paper describes a Bayesian approach for addressing hard-to-detect nuclides and chemical hot spots. The approach begins using available data (e.g., as collected using the standard approach) to predict the probability that an unacceptable hot spot is present somewhere in the exposure unit. This Bayesian approach may even be coupled with the graded sampling approach to optimize hot spot characterization. Once the investigator concludes that the presence of hot spots is likely, then the surveyor should use the data quality objectives process to generate an appropriate sample campaign that optimizes the identification of risk-relevant hot spots.

  19. Experimental Investigation of White Layer formation in Hard Turning

    Science.gov (United States)

    Umbrello, D.; Rotella, G.; Crea, F.

    2011-05-01

    Hard turning with super hard cutting tools, like PCBN or Ceramics inserts, represents an interesting advance in the manufacturing industry, regarding the finishing of hardened steels. This innovative machining technique is considered an attractive alternative to traditional finish grinding operations because of the high flexibility, the ability to achieve higher metal removal rates, the possibility to operate without the use of coolants, and the capability to achieve comparable workpiece quality. However, the surface integrity effects of hard machining need to be taken into account due to their influence on the life of machined components. In particular, the formation of a usually undesirable white layer at the surface needs further investigation. Three different mechanisms have been proposed as main responsible of the white layer genesis: (i) microstructural phase transformation due to a rapid heating and quenching, (ii) severe plastic deformation resulting in a homogenous structure and/or a very fine grain size microstructure; (iii) surface reaction with the environment. In this research, an experimental campaign was carried out and several experimental techniques were used in order to analyzed the machined surface and to understand which of the above mentioned theories is the main cause of the white layer formation when AISI 52100 hardened steel is machined by PCBN inserts. In particular, the topography characterization has obtained by means of optical and scanning electron microscope (SEM) while microstructural phase composition and chemical characterization have been respectively detected using X-ray Diffraction (XRD) and Energy-dispersive X-ray spectroscopy (EDS) techniques. The results prove that the white layer is the result of microstructural alteration, i.e. the generation of a martensitic structure.

  20. Detecting and correcting hard errors in a memory array

    Energy Technology Data Exchange (ETDEWEB)

    Kalamatianos, John; John, Johnsy Kanjirapallil; Gelinas, Robert; Sridharan, Vilas K.; Nevius, Phillip E.

    2015-11-19

    Hard errors in the memory array can be detected and corrected in real-time using reusable entries in an error status buffer. Data may be rewritten to a portion of a memory array and a register in response to a first error in data read from the portion of the memory array. The rewritten data may then be written from the register to an entry of an error status buffer in response to the rewritten data read from the register differing from the rewritten data read from the portion of the memory array.

  1. Hard-X-ray Zone Plates: Recent Progress

    Directory of Open Access Journals (Sweden)

    Syue-Ren Wu

    2012-09-01

    Full Text Available The technology to focus hard-X-rays (photon energy larger than 1–2 keV has made great progress in the past three years. The progress was particularly spectacular for lenses based on the Fresnel zone plate concept. The spatial resolution notably increased by a factor of three, opening up entirely new domains of application, specifically in biomedical research. As we shall see, this evolution is the result of a painstaking optimization of many different aspects rather than of a single technical breakthrough.

  2. Hard Sphere Diffusion Behaviour of Polymer Translocating through Interacting Pores

    Institute of Scientific and Technical Information of China (English)

    SUN Li-Zhen; LUO Meng-Bo

    2008-01-01

    The translocation of polymer chain through a small pore from a high concentration side (cis side) to a low concentration side (trans side) is simulated by using Monte Carlo technique. The effect of the polymer-pore interaction on the translocation is studied. We find a special interaction at which the decay of the number of polymer chain, N, at the cis side obeys Fick's law, i.e. N decreases exponentially with time. The behaviour is analogous to the diffusion of hard sphere.

  3. Aespoe Hard Rock Laboratory. Planning Report for 2011

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    This report presents the planned activities for the year 2011. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2010, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Background information on the projects is given in the Annual Report as well as findings and results.

  4. Radiation-hard/high-speed parallel optical links

    Energy Technology Data Exchange (ETDEWEB)

    Gan, K.K., E-mail: gan@mps.ohio-state.edu [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Buchholz, P.; Heidbrink, S. [Fachbereich Physik, Universität Siegen, Siegen (Germany); Kagan, H.P.; Kass, R.D.; Moore, J.; Smith, D.S. [Department of Physics, The Ohio State University, Columbus, OH 43210 (United States); Vogt, M.; Ziolkowski, M. [Fachbereich Physik, Universität Siegen, Siegen (Germany)

    2016-09-21

    We have designed and fabricated a compact parallel optical engine for transmitting data at 5 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5 Gb/s is satisfactory.

  5. Radiation-hard/high-speed parallel optical links

    Science.gov (United States)

    Gan, K. K.; Buchholz, P.; Heidbrink, S.; Kagan, H. P.; Kass, R. D.; Moore, J.; Smith, D. S.; Vogt, M.; Ziolkowski, M.

    2016-09-01

    We have designed and fabricated a compact parallel optical engine for transmitting data at 5 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5 Gb/s is satisfactory.

  6. Wear behaviour of epoxy resin filled with hard powders

    Science.gov (United States)

    Formisano, A.; Boccarusso, L.; Minutolo, F. Capece; Carrino, L.; Durante, M.; Langella, A.

    2016-10-01

    The development of high performance materials based on epoxy resin finds a growing number of applications in which high wear resistance is required. One major drawback in many of these applications is the relatively poor wear resistance of the epoxy resin. Therefore, in order to investigate on the possibility of increasing wear resistance of thermoset polymers filled with hard powders, sliding tests are carried out by means of a pin on disc apparatus. In particular, composite resins, constituted by an epoxy resin filled with different contents and sizes of Silicon Carbide powder, are analyzed; the wear resistance, in terms of volume loss, is measured for different abrasive counterfaces and loads.

  7. Aespoe Hard Rock Laboratory. Planning Report for 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-15

    This report presents the planned activities for the year 2010. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results

  8. Aespoe Hard Rock Laboratory. Planning Report for 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-02-15

    This report presents the planned activities for the year 2009. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results.

  9. Role of pion pole in hard exlusive meson leptoproduction

    CERN Document Server

    Goloskokov, Sergey

    2015-01-01

    We consider the pion pole contribution and transversity effects determined by the $H_T$ and $\\bar E_T$ Generalized Parton Distributions (GPDs) which are essential in hard pseudoscalar and vector meson leptoproduction. We investigate spin effects in the $\\omega$ and $\\rho^0$ reactions. It is shown that the pion pole contribution is very important in the $\\omega$ production. Such effects in the $\\rho^0$ channel are much smaller. Our results on spin asymmetries and spin density matrix elements in these reactions were found to be in good agreement with HERMES data.

  10. Density Functional Theory for General Hard-Core Lattice Gases

    Science.gov (United States)

    Lafuente, Luis; Cuesta, José A.

    2004-09-01

    We put forward a general procedure to obtain an approximate free-energy density functional for any hard-core lattice gas, regardless of the shape of the particles, the underlying lattice, or the dimension of the system. The procedure is conceptually very simple and recovers effortlessly previous results for some particular systems. Also, the obtained density functionals belong to the class of fundamental measure functionals and, therefore, are always consistent through dimensional reduction. We discuss possible extensions of this method to account for attractive lattice models.

  11. Bringing codecision to agriculture: a hard case of parliamentarization

    DEFF Research Database (Denmark)

    Roederer-Rynning, C.; Schimmelfennig, F.

    2012-01-01

    The Lisbon Treaty extended the codecision procedure to the Common Agricultural Policy. This is not only a hard case of parliamentarization but also a deviant case for existing explanations of the empowerment of the EP. We argue that the parliamentarization of agricultural policy in the EU cannot...... be explained by policy-seeking, inter-institutional bargaining or legitimacy-seeking behaviour - or by sectoral policy dynamics in general. In a process-tracing analysis we show that it was part of a broader process of legal rationalization and democratic constitutionalization in the constitutional Convention......, which prevailed over the resistance of vested policy interests....

  12. Hard and Soft Sub-Time-Optimal Robust Controllers

    DEFF Research Database (Denmark)

    Kulczycki, Piotr; Wisniewski, Rafal; Kowalski, Piotr

    2010-01-01

    has been treated as a stochastic process, is presented in this paper. As a result, through a generalization of the classic switching curve occurring in the time-optimal approach, two control structures have been investigated: the hard, defined on the basis of the rules of the statistical decision...... theory, and also the soft, which additionally allows the elimination of rapid changes in control values. The methodology proposed here may be easily adopted for other elements commonly found in mechanical systems, e.g. parameters of drive or motion resistance, giving the sub-time-optimal controlling...

  13. Hard-X-Ray-Induced Multistep Ultrafast Dissociation

    Science.gov (United States)

    Travnikova, Oksana; Marchenko, Tatiana; Goldsztejn, Gildas; Jänkälä, Kari; Sisourat, Nicolas; Carniato, Stéphane; Guillemin, Renaud; Journel, Loïc; Céolin, Denis; Püttner, Ralph; Iwayama, Hiroshi; Shigemasa, Eiji; Piancastelli, Maria Novella; Simon, Marc

    2016-05-01

    Creation of deep core holes with very short (τ ≤1 fs ) lifetimes triggers a chain of relaxation events leading to extensive nuclear dynamics on a few-femtosecond time scale. Here we demonstrate a general multistep ultrafast dissociation on an example of HCl following Cl 1 s →σ* excitation. Intermediate states with one or multiple holes in the shallower core electron shells are generated in the course of the decay cascades. The repulsive character and large gradients of the potential energy surfaces of these intermediates enable ultrafast fragmentation after the absorption of a hard x-ray photon.

  14. Cryogenic Si detectors for ultra radiation hardness in SLHC environment

    Science.gov (United States)

    Li, Zheng; Abreu, M.; Anbinderis, P.; Anbinderis, T.; Ambrosio, N. D.'.; de Boer, W.; Borchi, E.; Borer, K.; Bruzzi, M.; Buontempo, S.; Chen, W.; Cindro, V.; Dierlamm, A.; Eremin, V.; Gaubas, E.; Gorbatenko, V.; Grigoriev, E.; Hauler, F.; Heijne, E.; Heising, S.; Hempel, O.; Herzog, R.; Härkönen, J.; Ilyashenko, I.; Janos, S.; Jungermann, L.; Kalesinskas, V.; Kapturauskas, J.; Laiho, R.; Luukka, P.; Mandic, I.; De Masi, Rita; Menichelli, D.; Mikuz, M.; Militaru, O.; Niinikosky, T. O.; Shea, V. O.'.; Pagano, S.; Paul, S.; Piotrzkowski, K.; Pretzl, K.; Rato Mendes, P.; Rouby, X.; Ruggiero, G.; Smith, K.; Sonderegger, P.; Sousa, P.; Tuominen, E.; Tuovinen, E.; Verbitskaya, E.; Vaitkus, J.; Wobst, E.; Zavrtanik, M.

    2007-09-01

    Radiation hardness up to 10 16 neq/cm 2 is required in the future HEP experiments for most inner detectors. However, 10 16 neq/cm 2 fluence is well beyond the radiation tolerance of even the most advanced semiconductor detectors fabricated by commonly adopted technologies: the carrier trapping will limit the charge collection depth to an effective range of 20-30 μm regardless of depletion depth. Significant improvement of the radiation hardness of silicon sensors has been taken place within RD39. Fortunately the cryogenic tool we have been using provides us a convenient way to solve the detector charge collection efficiency (CCE) problem at SLHC radiation level (10 16 neq/cm 2). There are two key approaches in our efforts: (1) use of the charge/current injection to manipulate the detector internal electric field in such a way that it can be depleted at a modest bias voltage at cryogenic temperature range (⩽230 K); and (2) freezing out of the trapping centers that affects the CCE at cryogenic temperatures lower than that of the LN 2 temperature. In our first approach, we have developed the advanced radiation hard detectors using charge or current injection, the current injected diodes (CID). In a CID, the electric field is controlled by injected current, which is limited by the space charge, yielding a nearly uniform electric field in the detector, independent of the radiation fluence. In our second approach, we have developed models of radiation-induced trapping levels and the physics of their freezing out at cryogenic temperatures. In this approach, we intend to study the trapping effect at temperatures below LN 2 temperature. A freeze-out of trapping can certainly help in the development of ultra-radiation hard Si detectors for SLHC. A detector CCE measurement system using ultra-fast picosecond laser with a He cryostat has been built at CERN. This system can be used to find out the practical cryogenic temperature range that can be used to freeze out the

  15. Cryogenic Si detectors for ultra radiation hardness in SLHC environment

    Energy Technology Data Exchange (ETDEWEB)

    Li Zheng [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Abreu, M. [LIP, Av. E. Garcia, P-1000 Lisbon (Portugal); Anbinderis, P.; Anbinderis, T. [University of Vilnius, Institute of Materials Science and Applied Research, 2040 Vilnius (Lithuania); Ambrosio, N.D' . [Instiuto di Cibernetica ' E. Caianiello' , 80078 Pozzuoli (Italy); Boer, W. de [IEKP University of Karlsruhe, D-76128 Karlsruhe (Germany); Borchi, E. [Dipartimento di Energetica, Universita di Firenze, I-50139 Florence (Italy); Borer, K. [Laboratorium fuer Hochenergiephysik der Universitaet Bern, Sidlerstarsse 5, CH-3012 Bern (Switzerland); Bruzzi, M. [Dipartimento di Energetica, Universita di Firenze, I-50139 Firenze (Italy); Buontempo, S. [Instiuto di Cibernetica ' E. Caianiello' , 80078 Pozzuoli (Italy); Chen, W. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Cindro, V. [Jozef Stefan Institute, Exp. Particle Physics Department, PO. Box 3000, 1001 Ljubljana (Slovenia); Dierlamm, A. [IEKP University of Karlsruhe, D-76128 Karlsruhe (Germany); Eremin, V. [Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Gaubas, E.; Gorbatenko, V. [University of Vilnius, Institute of Materials Science and Applied Research, 2040 Vilnius (Lithuania); Grigoriev, E. [IEKP University of Karlsruhe, D-76128 Karlsruhe (Germany); Department de Radiologie, Universite de Geneve, CH-1211 Geneva (Switzerland); Hauler, F. [IEKP University of Karlsruhe, D-76128 Karlsruhe (Germany); Heijne, E. [CERN, CH-1211 Geneva (Switzerland); Heising, S. [IEKP University of Karlsruhe, D-76128 Karlsruhe (Germany)] (and others)

    2007-09-01

    Radiation hardness up to 10{sup 16} n{sub eq}/cm{sup 2} is required in the future HEP experiments for most inner detectors. However, 10{sup 16} n{sub eq}/cm{sup 2} fluence is well beyond the radiation tolerance of even the most advanced semiconductor detectors fabricated by commonly adopted technologies: the carrier trapping will limit the charge collection depth to an effective range of 20-30 {mu}m regardless of depletion depth. Significant improvement of the radiation hardness of silicon sensors has been taken place within RD39. Fortunately the cryogenic tool we have been using provides us a convenient way to solve the detector charge collection efficiency (CCE) problem at SLHC radiation level (10{sup 16} n{sub eq}/cm{sup 2}). There are two key approaches in our efforts: (1) use of the charge/current injection to manipulate the detector internal electric field in such a way that it can be depleted at a modest bias voltage at cryogenic temperature range ({<=}230 K); and (2) freezing out of the trapping centers that affects the CCE at cryogenic temperatures lower than that of the LN{sub 2} temperature. In our first approach, we have developed the advanced radiation hard detectors using charge or current injection, the current injected diodes (CID). In a CID, the electric field is controlled by injected current, which is limited by the space charge, yielding a nearly uniform electric field in the detector, independent of the radiation fluence. In our second approach, we have developed models of radiation-induced trapping levels and the physics of their freezing out at cryogenic temperatures. In this approach, we intend to study the trapping effect at temperatures below LN{sub 2} temperature. A freeze-out of trapping can certainly help in the development of ultra-radiation hard Si detectors for SLHC. A detector CCE measurement system using ultra-fast picosecond laser with a He cryostat has been built at CERN. This system can be used to find out the practical

  16. Composition Gradient Hard Coatings by Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    CHENJun; LINGuo-qiang; WANGFu-gang

    2004-01-01

    Arc Ion Plating can be used to synthesize multi-component composition gradient hard coatings by adjusting arc currents of metal targets. The present work aims at a comprehensive description of such a technique. The examples of TiAl multi-layer alloy coatings and (Ti,M) N composition-gradient films were taken (M representing Zr, Nb etc.) for the purpose of explaining the working process and evaluating practical effects. The results show that this technique has the advantages of easy manipulation, rapid deposition, and wide composition range.

  17. Excluded-volume effects in the diffusion of hard spheres

    KAUST Repository

    Bruna, Maria

    2012-01-03

    Excluded-volume effects can play an important role in determining transport properties in diffusion of particles. Here, the diffusion of finite-sized hard-core interacting particles in two or three dimensions is considered systematically using the method of matched asymptotic expansions. The result is a nonlinear diffusion equation for the one-particle distribution function, with excluded-volume effects enhancing the overall collective diffusion rate. An expression for the effective (collective) diffusion coefficient is obtained. Stochastic simulations of the full particle system are shown to compare well with the solution of this equation for two examples. © 2012 American Physical Society.

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

    Energy Technology Data Exchange (ETDEWEB)

    Viveros-Méndez, P. X., E-mail: xviveros@fisica.uaz.edu.mx; Aranda-Espinoza, S. [Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad esq. Paseo, La Bufa s/n, 98060 Zacatecas, Zacatecas, México (Mexico); Gil-Villegas, Alejandro [Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Campus León, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 León, Guanajuato, México (Mexico)

    2014-07-28

    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)/(e{sup 2}/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 L{sub x} ≈ L{sub y} and L{sub z} = 5L{sub x}, where L{sub x}, L{sub y}, and L{sub z} 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.

  19. Aespoe Hard Rock Laboratory. Status Report. April - June 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2005- 2010 are presented in SKB's RDandD-Programme 2004 /SKB 2004/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2007/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the second quarter 2007

  20. New solutions of mining tools for hard rock mining

    Energy Technology Data Exchange (ETDEWEB)

    Kotwica, K.; Dasgupta, S. [University of Mining and Metallurgy, Cracow (Poland). Dept. of Mining, Dressing and Transportation Machines

    2002-12-01

    This article presents new solutions of mining tools for hard rock mining and the test results of research in the laboratory stand constructed at the University of Mining and Metallurgy in Crakow for cutting of artificial samples of rock with new mining tools. New solutions of rotary picks and non-symmetric disk cutters have been used. During the studies of the pick edge wear, force and mining effect were measured, using several selected mining parameters. Results obtained with new bell-type pick and disc cutters have proved very encouraging. 2 refs., 12 figs., 1 tab.