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1

Knoop Hardness - Apparent Yield Stress Relationship in Ceramics  

SciTech Connect

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.

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

2

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

E-print Network

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...

American Society for Testing and Materials. Philadelphia

2007-01-01

3

Effects of irradiance, wavelength, and thermal emission of different light curing units on the Knoop and Vickers hardness of a composite resin.  

PubMed

The aim of this study was to evaluate the effects of irradiance, light emission wavelength, and heating of different light curing units on the Knoop and Vickers hardness of a hybrid composite resin. The specimens were irradiated during 40 s with ten different light curing units, LEDs, and halogen lights. The spectral emission of each light curing unit was assessed by a spectrometer, the irradiance was measured by two commercial radiometers, and the heating measured with a thermocouple. After 48 h of storage in a dark recipient under a 100% humidity condition, the Knoop and Vickers hardness tests were carried out. The hardness results were analyzed by ANOVA, and Tukey HSD test (p < 0.05). The results showed that the surface hardness of the composite resin depends not only on the irradiance, but strongly on the emission wavelength and heating of the light curing units. It was observed, a linear correlation between the conversion degree and radiant exposure. In addition, it is suggested that the well known base to top surface hardness ratio convention of 80-90% is not appropriate to evaluate curing efficiency of composites, since the top surface is not always sufficiently polymerized. PMID:17853418

Torno, Vladja; Soares, Paulo; Martin, Juliana M H; Mazur, Rui F; Souza, Evelise M; Vieira, Sérgio

2008-04-01

4

Influence of successive light-activation on degree of conversion and knoop hardness of the first layered composite increment.  

PubMed

Abstract Purpose: To evaluate the influence of light-activation of second, third and fourth increments on degree of conversion (DC) and microhardness (KHN) of the top (T) and bottom (B) surface of the first increment. Materials and methods. Forty samples (n = 5) were prepared. In groups 1-4, after each increment light-activation (multiple irradiation), T and B of the first increment were measured in DC and KHN. In groups 5-8, only the first increment was made (single irradiation) and measurements of DC and KHN were taken at 15 min intervals. The light-activation modes were (XL) 500 mW/cm(2) × 38 s (G1/G5); (S) 1000 mW/cm(2) × 19 s (G2/G6), (HP) 1400 mW/cm(2) × 14 s (G3/G7); (PE) 3200 mW/cm(2) × 6 s (G4/G8). Data for DC and KHN were analyzed separately by using PROC MIXED for repeated measures and Tukey-Kramer test (? = 0.05). Results. For KHN, B showed lower values than T. PE resulted in lower values of KHN in B surface. For single and multiple irradiations, T and B of first measurement showed the lowest KHN and the fourth measurement showed the highest, with significant difference between them. For single irradiation, first and second increments presented similar KHN, different from the third and fourth increment, which did not differ between them. For multiple irradiations, the second light-activation resulted in KHN similar to first, third and fourth increments. For DC, except QTH, T presented higher DC than B. Conclusion. The light-activation of successive increments was not able to influence the KHN and DC of the first increment. PMID:25314123

Caldas Giorgi, Maria Cecília; Theobaldo, Jéssica; Nunes Leite Lima, Débora Alves; Marchi, Giselle Maria; Ambrosano, Gláucia Maria; Baggio Aguiar, Flávio Henrique

2015-02-01

5

Traceability in hardness measurements: from the definition to industry  

NASA Astrophysics Data System (ADS)

The measurement of hardness has been and continues to be of significant importance to many of the world's manufacturing industries. Conventional hardness testing is the most commonly used method for acceptance testing and production quality control of metals and metallic products. Instrumented indentation is one of the few techniques available for obtaining various property values for coatings and electronic products in the micrometre and nanometre dimensional scales. For these industries to be successful, it is critical that measurements made by suppliers and customers agree within some practical limits. To help assure this measurement agreement, a traceability chain for hardness measurement traceability from the hardness definition to industry has developed and evolved over the past 100 years, but its development has been complicated. A hardness measurement value not only requires traceability of force, length and time measurements but also requires traceability of the hardness values measured by the hardness machine. These multiple traceability paths are needed because a hardness measurement is affected by other influence parameters that are often difficult to identify, quantify and correct. This paper describes the current situation of hardness measurement traceability that exists for the conventional hardness methods (i.e. Rockwell, Brinell, Vickers and Knoop hardness) and for special-application hardness and indentation methods (i.e. elastomer, dynamic, portables and instrumented indentation).

Germak, Alessandro; Herrmann, Konrad; Low, Samuel

2010-04-01

6

Fatigue life of cold-forging dies with various values of hardness  

Microsoft Academic Search

Four selected die materials commonly used in the cold-forging process were examined in the present study to obtain the relationship between the hardness and the die fatigue life. The die materials were first heat-treated by a developed process to obtain different values of hardness, while the ductility was retained at a favorable level. The material properties of these die materials

Yi-Che Lee; Fuh-Kuo Chen

2001-01-01

7

Evaluation of r-value of steels using Vickers hardness test  

NASA Astrophysics Data System (ADS)

The plastic strain ratio (Lankford value, r-value) is an index of mechanical anisotropy of sheet metals. The Vickers hardness is measured to determine the r-value. Tensile and indentation tests of three kinds of commercial steel sheets are conducted in directions 0°, 45° and 90° to the rolling direction. A relationship is found between the r-value and impression aspect ratio by a hardness tester. The aspect ratio is defined as the ratio of the diagonal length in the longitudinal direction to that in the thickness direction.

Ohashi, Kazutoshi; Utsunomiya, Hiroshi; Matsumoto, Ryo

2012-08-01

8

Can cone beam CT predict the hardness of interradicular cortical bone?  

PubMed Central

Objectives Orthodontic mini implants can be inserted at the interradicular site. The bone quality at this site may affect the stability and anchorage of the implant. Bone density is clinically evaluated by Hounsfield units (HU) obtained from cone beam CT (CBCT). The objective of this study was to determine the correlations between HU, microhardness and cortical bone thickness of interradicular site at various segments (anterior/posterior) and aspects (buccal/lingual) of both jaws in a swine model. Materials and methods Eight mandible and maxilla swine bones were scanned by CBCT. The HU and thickness of the above-mentioned sites were determined. Then, a Knoop microhardness test was applied and the Knoop Hardness Number was obtained (KHN). Results The mandible parameters spread over a wider range than the maxilla. The buccal aspect of the maxilla had higher HU and KHN values than the mandible. The lingual aspect of the mandible had higher KHN values than the maxilla. Posterior segments had higher HU and KHN values. The thickness of the alveolar cortical bone was greater in the maxilla than in the mandible. Correlations were found between HU and KHN for 3 of the 4 sites (anterior or posterior, buccal or lingual) of the mandible only. No correlations were found for the maxilla. Upon pooling the HU and KHN data for the whole jaw, correlation was found for the maxilla as well. Conclusions Relying on HU values as a predictor of cortical bone hardness should be considered with caution. PMID:24735746

2014-01-01

9

Singular Value Decomposition of the Radial Distribution Function for Hard Sphere and Square Well Potentials  

PubMed Central

We compute the singular value decomposition of the radial distribution function for hard sphere, and square well solutions. We find that decomposes into a small set of basis vectors allowing for an extremely accurate representation at all interpolated densities and potential strengths. In addition, we find that the coefficient vectors describing the magnitude of each basis vector are well described by a low-order polynomial. We provide a program to calculate in this compact representation for the investigated parameter range. PMID:24143174

Hoppe, Travis

2013-01-01

10

Singular Values of Products of Ginibre Random Matrices, Multiple Orthogonal Polynomials and Hard Edge Scaling Limits  

NASA Astrophysics Data System (ADS)

Akemann, Ipsen and Kieburg recently showed that the squared singular values of products of M rectangular random matrices with independent complex Gaussian entries are distributed according to a determinantal point process with a correlation kernel that can be expressed in terms of Meijer G-functions. We show that this point process can be interpreted as a multiple orthogonal polynomial ensemble. We give integral representations for the relevant multiple orthogonal polynomials and a new double contour integral for the correlation kernel, which allows us to find its scaling limits at the origin (hard edge). The limiting kernels generalize the classical Bessel kernels. For M = 2 they coincide with the scaling limits found by Bertola, Gekhtman, and Szmigielski in the Cauchy-Laguerre two-matrix model, which indicates that these kernels represent a new universality class in random matrix theory.

Kuijlaars, Arno B. J.; Zhang, Lun

2014-12-01

11

443R. Bock and V. Knoop (eds.), Genomics of Chloroplasts and Mitochondria, Advances in Photosynthesis and Respiration 35, pp. 443458,  

E-print Network

443R. Bock and V. Knoop (eds.), Genomics of Chloroplasts and Mitochondria, Advances+Business Media B.V. 2012 Chapter 19 Transformation and Nucleic Acid Delivery to Mitochondria Claire Remacle and RNA Delivery into Plant Mitochondria

Hamel, Patrice

12

Finite element analysis of stresses in Berkovich, Vickers and Knoop indentation for densifying and non-densifying glasses  

Microsoft Academic Search

A constitutive law for fused silica accounting for its permanent densification under large compressive stresses is presented. The implementation of the constitutive equations in the general-purpose finite element code ABAQUS via user subroutine is proposed and carefully verified. The three-dimensional indentation mechanics under Berkovich, Vickers and Knoop indenters is extensively investigated based on the proposed constitutive relation. The results of

Kanghua Chen

2002-01-01

13

Finite element analysis of stresses in Berkovich, Vickers and Knoop indentation for densifying and non-densifying glasses  

NASA Astrophysics Data System (ADS)

A constitutive law for fused silica accounting for its permanent densification under large compressive stresses is presented. The implementation of the constitutive equations in the general-purpose finite element code ABAQUS via user subroutine is proposed and carefully verified. The three-dimensional indentation mechanics under Berkovich, Vickers and Knoop indenters is extensively investigated based on the proposed constitutive relation. The results of stress distribution and plastic zone for both densifying and non-densifying optical glasses are systematically compared. These numerical results are in good agreement with the experimental observations of optical manufacturing. That is, fused silica shows lower material removal rate, smaller surface roughness and subsurface damage in contrast to non-densifying optical glasses under the same grinding condition. Material densification of fused silica is thoroughly studied through numerical simulations of indentation mechanics. The exact amount of densification and shear strain of fused silica under Berkovich indentation is calculated to show the deformation mechanism of glass materials under three-dimensional indentations. The surface profiles show the material "pile-up" around the indenter tip for non-densifying glasses and "sink-in" for fused silica after the indentation load is removed. An important inverse problem is studied: estimation of abrasive size and indentation load through the examination of residual indentation footprints. A series of 2D axisymmetric spherical indentation simulations generate a wide range of relationships among the indentation load, indenter size, residual indentation depth and size of residual indentation zone for the five selected brittle materials: glass fused silica (FS), BK7, semiconductor Si, laser glass LHG8, and optical crystal CaF2.. The application of the inverse problem is verified by the good agreement between the estimated abrasive size and the actual abrasive size found during a material removal experiment of magnetorheological finishing (MRF) of fused silica. The explanation of indentation size effect (ISE) is attempted using numerical indentation simulations. Vickers indentation simulations on the five selected brittle materials (FS, BK7, Si, LHG8 and CaF2.) show no size dependence of Vickers hardness when the material is modeled as elastic-perfectly plastic (with or without densification). The simulation results on axisymmetric conical indentation also indicate that the bluntness of the indenter tip is not the reason for the indentation size effect. A new constitutive model accounting for the material length scale is needed in order to explain the well-observed indentation size effect during indentation tests.

Chen, Kanghua

2002-08-01

14

Silicon-containing diamond like-carbon coatings formed by ion beam assisted deposition (IBAD): Processing and properties of a new category of hard, wear resistant thin films  

SciTech Connect

Amorphous silicon-containing diamond like-carbon Si-DLQ coatings were formed by thermal evaporation of a tetraphenyl-tetramethyl-trisiloxane ((C{sub 6}H{sub 5}){sub 4}(CH{sub 3}){sub 4}Si{sub 3}O{sub 2}) diffusion pump oil (Dow Corning 704) onto silicon and steel substrates with simultaneous bombardment of the growing film with 40 keV Ar{sup +} ions to decompose the (C{sub 6}H{sub 5}){sub 4}(CH{sub 3}){sub 4}Si{sub 3}O{sub 2} molecules. Both the current density of the ion beam and the oil arrival rate were varied to produce hard, adhesive films on room temperature substrates, with densities ranging from 1.4 to 2.3 g/cm{sup 3} and Knoop microhardness values (at 15 g load) from 1000 to 2100 MPa.

Fountzoulas, C.G.; Demaree, J.D.; Hirvonen, J.K. [Univ. of Connecticut, Storrs, CT (United States)] [and others

1995-12-31

15

A Case Study on Investigating the Effect of Genetic Algorithm Operators on Predicting the Global Minimum Hardness Value of Biomaterial Extrudate  

SciTech Connect

Crossover and mutation are the main search operators of genetic algorithm, one of the most important features which distinguish it from other search algorithms like simulated annealing. A genetic algorithm adopts crossover and mutation as their main genetic operators. The present work was aimed to see the effect of genetic algorithm operators like crossover and mutation (Pc & Pm), population size (n), and number of iterations (I) on predicting the minimum hardness (N) of the biomaterial extrudate. The second order polynomial regression equation developed for the extrudate property hardness in terms of the independent variables like barrel temperature, screw speed, fish content of the feed, and feed moisture content was used as the objective function in the GA analysis. A simple genetic algorithm (SGA) with a crossover and mutation operators was used in the present study. A program was developed in C language for a SGA with a rank based fitness selection method. The upper limit of population and iterations were fixed at 100. It was observed that increasing population and iterations the prediction of function minimum improved drastically. Minimum predicted hardness values were achievable with a medium population of 50, iterations of 50 and crossover and mutation probabilities of 50 % and 0.5 %. Further the Pareto charts indicated that the effect of Pc was found to be more significant when population is 50 and Pm played a major role at low population ( 10). A crossover probability of 50 % and mutation probability of 0.5 % are the threshold values for the convergence of GA to reach a global search space. A minimum predicted hardness value of 3.82 (N) was observed for n = 60 and I = 100 and Pc & Pm of 85 % and 0.5 %.

Shankar, T.J. [University of British Columbia, Vancouver; Sokhansanj, Shahabaddine [ORNL

2010-02-01

16

The Aesthetic Value of Littoral Hard Substrata and Consideration of Ethical Frameworks for Their Investigation and Conservation  

Microsoft Academic Search

\\u000a Rocky coastlines provide impressive vistas. The recreational and aesthetic value of rocky intertidal areas encompasses a large\\u000a proportion of their ecosystem services, along with provisioning and regulatory services such as nutrient regulation and supply\\u000a of food. Ethical considerations are confusing but critical to any discussions on the use of rocky shores. We must ensure an\\u000a appropriate mix between exploitation (e.g.

Heather E. Sugden; A. J. Underwood; Stephen J. Hawkins

17

Hybrid hard- and soft-modeling of spectrophotometric data for monitoring of ciprofloxacin and its main photodegradation products at different pH values  

NASA Astrophysics Data System (ADS)

A simple and fast on line spectrophotometric method combined with a hybrid hard-soft modeling multivariate curve resolution (HS-MCR) was proposed for the monitoring of photodegradation reaction of ciprofloxacin under UV radiation. The studied conditions attempt to emulate the effect of sunlight on these antibiotics that could be eventually present in the environment. The continuous flow system made it possible to study the ciprofloxacin degradation at different pH values almost at real time, avoiding errors that could arise from typical batch monitoring of the reaction. On the base of a concentration profiles obtained by previous pure soft-modeling approach, reaction pathways have been proposed for the parent compound and its photoproducts at different pH values. These kinetic models were used as a constraint in the HS-MCR analysis. The kinetic profiles and the corresponding pure response profile (UV-Vis spectra) of ciprofloxacin and its main degradation products were recovered after the application of HS-MCR analysis to the spectra recorded throughout the reaction. The observed behavior showed a good agreement with the photodegradation studies reported in the bibliography. Accordingly, the photodegradation reaction was studied by high performance liquid chromatography coupled with UV-Vis diode array detector (HPLC-DAD). The spectra recorded during the chromatographic analysis present a good correlation with the ones recovered by UV-Vis/HS-MCR method.

Razuc, Mariela; Garrido, Mariano; Caro, Yamile S.; Teglia, Carla M.; Goicoechea, Héctor C.; Fernández Band, Beatriz S.

2013-04-01

18

Young's modulus and fracture during Knoop indentation of potassium, rubidium, cesium, and ammonium acid phthalate single crystals on the (010) plane  

NASA Astrophysics Data System (ADS)

The correlation of the anisotropy of the Young's modulus of organic single crystals of potassium, rubidium, cesium, and ammonium acid phthalates with strain and fracture patterns during Knoop indentation on the (010) cleavage plane in the [001] and [100] directions has been studied. The data on the maximum anisotropy of the strain and fracture patterns of the ammonium acid phthalate single crystal have been discussed in view of the published data on the structure, mechanical, elastic, and X-ray spectral properties of these crystals.

Sizova, N. L.; Moiseeva, N. A.

2012-12-01

19

Effect of curing mode on the hardness of dual-cured composite resin core build-up materials.  

PubMed

This study evaluated the Knoop Hardness (KHN) values of two dual-cured composite resin core build-up materials and one resin cement exposed to different curing conditions. Two dual-cured core build-up composite resins (LuxaCore-Dual, DMG; and FluoroCore2, Dentsply Caulk), and one dual-cured resin cement (Rely X ARC, 3M ESPE) were used in the present study. The composite materials were placed into a cylindrical matrix (2 mm in height and 3 mm in diameter), and the specimens thus produced were either light-activated for 40 s (Optilux 501, Demetron Kerr) or were allowed to self-cure for 10 min in the dark (n = 5). All specimens were then stored in humidity at 37 degrees C for 24 h in the dark and were subjected to KHN analysis. The results were submitted to 2-way ANOVA and Tukey's post-hoc test at a pre-set alpha of 5%. All the light-activated groups exhibited higher KHN values than the self-cured ones (p = 0.00001), regardless of product. Among the self-cured groups, both composite resin core build-up materials showed higher KHN values than the dual-cured resin cement (p = 0.00001). LuxaCore-Dual exhibited higher KHN values than FluoroCore2 (p = 0.00001) when they were allowed to self-cure, while no significant differences in KHN values were observed among the light-activated products. The results suggest that dual-cured composite resin core build-up materials may be more reliable than dual-cured resin cements when curing light is not available. PMID:20658046

Arrais, César Augusto Galvão; Kasaz, Aline de Cerqueira; Albino, Luís Gustavo Barrote; Rodrigues, José Augusto; Reis, Andre Figueiredo

2010-01-01

20

Glass ionomer cement hardness after different materials for surface protection.  

PubMed

The aim of the present study was to evaluate the Knoop hardness of high viscous glass ionomer cement (GIC) Ketac Molar Easy Mix (3M ESPE, Saint Paul, USA) submitted to different types of compounds for surface protection. Sixty specimens of GIC were made in PVC molds with 7.5 mm diameter and 2.5 mm thickness. Divided in 6 groups: G1, Control (no protection); G2, Cavitine (Copal varnish); G3, Magic bond (Adhesive); G4, Adper Single Bond 2 (Single bottle adhesive); G5, Solid Petroleum Jelly; G6, Nail Varnish. The surface protection was applied after initial setting reaction. The specimens were immersed in deionized water, at 37 degrees C, for 24 h. The surfaces were polished in a rotation machine (Aropol 2V). The hardness test was accomplished in a Digital Microhardness tester HVS-100. In each specimen five indentations were done and repeated after 30 days and 4 months, under the same conditions. The results were submitted to Two-way ANOVA and Tukey Test. The only material that differed from the control group was the nail varnish (p < 0.001), with the other materials showing no significant difference from the control group. It was concluded that the best material for surface protection of GIC was the nail varnish, but because of possible harmful effects, petroleum jelly could be a better option. PMID:19557791

Brito, Cecilia R; Velasco, Leandro G; Bonini, Gabriela A V C; Imparato, José Carlos P; Raggio, Daniela P

2010-04-01

21

SUPER HARD SURFACED POLYMERS  

SciTech Connect

High energy ion beam surface treatments were applied to a selected group of polymers. Of the six materials in the present study, four were thermoplastics (polycarbonate, polyethylene, polyethylene terephthalate, and polystyrene) and two were thermosets (epoxy and polyimide). The particular epoxy evaluated in this work is one of the resins used in formulating fiber reinforced composites for military helicopter blades. Measures of mechanical properties of the near surface regions were obtained by nanoindentation hardness and pin on disk wear. Attempts were also made to measure erosion resistance by particle impact. All materials were hardness tested. Pristine materials were very soft, having values in the range of approximately 0.1 to 0.5 GPa. Ion beam treatment increased hardness by up to 50 times compared to untreated materials. For reference, all materials were hardened to values higher than those typical of stainless steels. Wear tests were carried out on three of the materials, PET, PI and epoxy. On the ion beam treated epoxy no wear could be detected, whereas the untreated material showed significant wear.

Mansur, Louis K [ORNL] [ORNL; Bhattacharya, R [UES, Incorporated, Dayton, OH] [UES, Incorporated, Dayton, OH; Blau, Peter Julian [ORNL] [ORNL; Clemons, Art [ORNL] [ORNL; Eberle, Cliff [ORNL] [ORNL; Evans, H B [UES, Incorporated, Dayton, OH] [UES, Incorporated, Dayton, OH; Janke, Christopher James [ORNL] [ORNL; Jolly, Brian C [ORNL] [ORNL; Lee, E H [Consultant, Milpitas, CA] [Consultant, Milpitas, CA; Leonard, Keith J [ORNL] [ORNL; Trejo, Rosa M [ORNL] [ORNL; Rivard, John D [ORNL] [ORNL

2010-01-01

22

Hardness of Electrodeposited Nano-Nickel Revisited  

NASA Astrophysics Data System (ADS)

In the past, hardness measurements on nanocrystalline metals were limited to Vickers microhardness and nano-indentation tests, mainly due to sample size/thickness limitations. On the other hand, most industries require hardness values on the Rockwell scale and make extensive use of hardness conversion relationships for various hardness scales. However, hardness conversions currently do not exist for nanocrystalline metals. With recent advances in electrodeposition technology, thicker specimens with a wide range of grain sizes can now be produced. In this study, the relationships between Vickers and Rockwell hardness scales have been developed for such materials. In addition, hardness indentations were used to gain further insight into the work hardening of nanocrystalline and polycrystalline nickel. Vickers microhardness and nano-indentation profiles below large Rockwell indentations showed that polycrystalline nickel exhibited considerable strain hardening, as expected. On the other hand, for nanocrystalline nickel the micro-Vickers and nano-indentations hardness profile showed low strain hardening capacity.

Tang, Bill Tsz Fai

23

Hard arc-sprayed coating with enhanced erosion and abrasion wear resistance  

NASA Astrophysics Data System (ADS)

A cored wire formulation, referred to as Alpha 1800, has been developed to produce tailored arc-sprayed coatings that are tough enough to resist particle impacts at 90° and sufficiently hard to deflect eroding particles at low impact angles. One millimeter thick coatings composed of ductile and hard phases with a Knoop hardness reaching 1800 kg/mm2 were easily produced by arc spraying the cored wire with air. Coatings were (1) erosion tested at 25 °C and higher temperatures at impact angles of 25 and 90° in a gasblast erosion rig, (2) slurry erosion tested at impact angles of 25 and 90°, and (3) abrasion wear tested using the ASTM G-65 test procedure. Results show that coatings produced with the new cored wire are at least 5 times more erosion resistant and 10 times more abrasion resistant than coatings produced by arc spraying commercial cored wires. The performance of the new arc-sprayed coating can be compared with that of high-energy WC-based coatings. Maintaining their erosion resistance after being exposed to temperatures up to 850 °C and possessing good oxidation resistance, arc-sprayed coatings produced with the new cored wire are attractive for applications in many industrial sectors involving high temperatures.

Dallaire, S.

2001-09-01

24

STP Hard Disks Metropolis Program  

NSDL National Science Digital Library

The STP Hard Disks Metropolis program is a Monte Carlo simulation of hard disks in two dimensions. The default initial condition is a rectangular configuration of N=64 particles in a box of length L = 40. You can slowly increase the density of the gas (by setting the minimum scale length between centers to a value slightly less than 1) to explore phase transitions. STP HardDisksMetropolis is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double-clicking the stp_HardDisksMetropolis.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2009-03-06

25

Confined Hard Disk System Model  

NSDL National Science Digital Library

The Confined Hard Disk System is an idealized statistical mechanics model that simulates a two-dimensional system of hard disks confined to a box with a constant temperature thermal reservoir at one end and a movable piston at the other. Slow-moving particles are color-coded as blue and fast particles are color-coded as yellow. The model computes and plots the time evolution of the kinetic energy K per particle, the pressure P, and the volume V. The model also displays histograms and mean values of these quantities. The Confined Hard Disk System was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_stp_hd_ConfinedHardDiskSystem.jar file will run the program if Java is installed.

Christian, Wolfgang

2010-12-27

26

Conductivity and hardness changes in aged compacts.  

PubMed

Batches of sodium, potassium, and ammonium chloride tablets containing no excipients and spray-dried lactose tablets containing 0.5% magnesium stearate were stored at 20 and 76% relative humidity. Electrical resistance and hardness measurements were made within 1 hr after compression and at intervals during a 45-day period. Hardness values of sodium, potassium, and ammonium chloride tablets stored at 20% relative humidity increased from 70 to 200% at 45 days, while conductances decreased 10-fold. Tablets stored at 76% relative humidity showed no increases or slight decreases in hardness with slight increases in conductance. Lactose tablets decreased slightly in hardness with corresponding increases in conductance. PMID:458612

Bhatia, R P; Lordi, N G

1979-07-01

27

How Hard is Chocolate?  

NSDL National Science Digital Library

Hardness is probably a concept you are well familiar with. You already know that certain materials are harder than others; in fact, you prove it everyday when you chew your food and your teeth don’t break (because your teeth are harder than the foods you chew). Hardness can be defined as a material's ability to resist a change in shape. Modern hardness testers take a well-defined shape and press it into a material with a certain force, observing the indent it leaves in the material when it is removed. In this lesson, you will be performing hardness testing on different bars of chocolate.

2007-12-20

28

Session: Hard Rock Penetration  

SciTech Connect

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.

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

1992-01-01

29

Memory Hard Drive Peripherals  

E-print Network

1! CSI3131 Topics CPU Memory Hard Drive Peripherals Computing Systems OS Overview StructureDeadlocks M em ory M anagem ent Basic Memory Managermtn Virtual Memory Storage and I/O File Systems Hard Drive Management Swap I/O Management 2 Module 7: Memory Management Reading: Chapter 8 § To provide a detailed

Stojmenovic, Ivan

30

The hard metal diseases  

SciTech Connect

Hard metal is a mixture of tungsten carbide and cobalt, to which small amounts of other metals may be added. It is widely used for industrial purposes whenever extreme hardness and high temperature resistance are needed, such as for cutting tools, oil well drilling bits, and jet engine exhaust ports. Cobalt is the component of hard metal that can be a health hazard. Respiratory diseases occur in workers exposed to cobalt--either in the production of hard metal, from machining hard metal parts, or from other sources. Adverse pulmonary reactions include asthma, hypersensitivity pneumonitis, and interstitial fibrosis. A peculiar, almost unique form of lung fibrosis, giant cell interstitial pneumonia, is closely linked with cobalt exposure.66 references.

Cugell, D.W. (Department of Medicine, Northwestern University Medical School, Chicago, IL (United States))

1992-06-01

31

Hydrogen bonding and mechanical properties in segmented montmorillonite\\/polyurethane nanocomposites of different hard segment ratios  

Microsoft Academic Search

Hydrogen bonding in the hard segments of the synthesized montmorillonite\\/polyurethane nanocomposites of various hard segment ratios was found to decrease with the increasing amount of montmorillonite regardless of the hard segment ratios, but reached plateau values at 5wt% montmorillonite concentration. The maximal reductions of the hydrogen bonding in the polyurethane nanocomposites ranged from 20 to 37%, depending on the hard

Y. I Tien; K. H Wei

2001-01-01

32

Counting coins and value  

NSDL National Science Digital Library

Students will identify and add up coins. Please complete the games in order. You must finish each game before going on to the next one. Game #1: Counting Money - Values of coins Game #2:Counting Money (harder) Game #3: Let s Compare (hardest) Game #4: Money Hard Game #5: Cash Out--Very Difficult Math Game ...

Christian, Mrs.

2007-03-21

33

What Would You Work Hard For?  

NSDL National Science Digital Library

This lesson plan helps young children begin to learn about the concept of value and why some items are considered more valuable than others. These concepts relate to a geographical understanding of natural resources and the reasons why people work very hard to extract resources, such as during the California gold rush. This lesson has students go through a simulation to learn about value, abundance, and scarcity and asks them to consider the things that they would be willing to work very hard for.

34

Laser quench hardening of steel: Effects of superimposed elastic pre-stress on the hardness and residual stress distribution  

NASA Astrophysics Data System (ADS)

Cold drawn AISI 4140 beams were LASER surface hardened with a 2 kW CO2 LASER. Specimens were treated in the free state and while restrained in a bending fixture inducing surface tensile stresses of 94 and 230 MPa. Knoop hardness indentation was used to evaluate the through thickness hardness distribution, and a layer removal methodology was used to evaluate the residual stress distribution. Results showed the maximum surface hardness attained was not affected by pre-stress during hardening, and ranged from 513 to 676 kg/mm2. The depth of effective hardening varied at different magnitudes of pre-stress, but did not vary proportionately to the pre-stress. The surface residual stress, coinciding with the maximum compressive residual stress, increased as pre-stress was increased, from 1040 MPa for the nominally treated specimens to 1270 MPa for specimens pre-stressed to 230 MPa. The maximum tensile residual stress observed in the specimens decreased from 1060 MPa in the nominally treated specimens to 760 MPa for specimens pre-stressed to 230 MPa. Similarly, thickness of the compressive residual stress region increased and the depth at which maximum tensile residual stress occurred increased as the pre-stress during treatment was increased Overall, application of tensile elastic pre-stress during LASER hardening is beneficial to the development of compressive residual stress in AISI 4140, with minimal impact to the hardness attained from the treatment. The newly developed approach for LASER hardening may support efforts to increase both the wear and fatigue resistance of parts made from hardenable steels.

Meserve, Justin

35

Hard Probes at RHIC  

NASA Astrophysics Data System (ADS)

Measurements of jets and heavy ?avour, the so called hard probes, play a crucial role in understanding properties of hot and dense nuclear matter created in high energy heavy-ion collisions. The measurements at the Relativistic Heavy Ion Collider (RHIC) showed that in central Au+Au collisons at RHIC energy ( ?sNN = 200 GeV) the nuclear matter created has properties close to those of perfect liquid, manifests partonic degrees of freedom and is opaque to hard probes. In order to draw quantitative conclusions on properties of this hot and dense nuclear matter reference measurements in proton-proton collisions and d+Au collisions are essential to estimate cold nuclear matter effects. In this proceedings a review of recent results on hard probes measurements in p+p, d+Au and A+A collisions as well as of beam energy dependence of jet quenching from STAR and PHENIX experiments at RHIC is presented.

Biel?íková, Jana

2014-04-01

36

CSI: Hard Drive  

ERIC Educational Resources Information Center

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.…

Sturgeon, Julie

2008-01-01

37

Work Hard. Be Nice  

ERIC Educational Resources Information Center

In 1994, fresh from a two-year stint with Teach for America, Mike Feinberg and Dave Levin inaugurated the Knowledge Is Power Program (KIPP) in Houston with an enrollment of 49 5th graders. By this Fall, 75 KIPP schools will be up and running, setting children from poor and minority families on a path to college through a combination of hard work,…

Mathews, Jay

2009-01-01

38

Running in Hard Times  

ERIC Educational Resources Information Center

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,…

Berry, John N., III

2009-01-01

39

Hard Sphere Gas Model  

NSDL National Science Digital Library

The Ejs Hard Sphere Gas model displays a three-dimensional (ideal) gas made out of hard disks. Particles are initialized with a random speed and in a random direction and move with constant velocity until a collision occurs. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting âOpen Ejs Modelâ from the pop-up menu item. Ejs Hard Sphere Gas model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_newton_HardShpereGas.jar file will run the program if Java is installed. Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional Ejs models for statistical mechanics are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.

Christian, Wolfgang

2008-07-06

40

Place Value  

NSDL National Science Digital Library

Practice place value! Fight the pirates in Pirates Place Value Uncover the hidden picture in Place value hidden picture Take the quiz at place value quiz Keep practicing with Place value to 1000 Stretch your brain with Place value to 100,000 ...

Peake, Mrs.

2011-08-18

41

Local hardness equalization and the principle of maximum hardness.  

PubMed

The chemical potential, hardness, and hyperhardnesses equalization principles are used to show that the leading term associated with charge transfer in the total interaction energy among the fragments in which a molecule is divided is directly proportional to minus the hardness of the molecule in its ground state, as established by the principle of maximum hardness. The additional terms in the interaction energy, associated with the changes in the external potential of the fragments, provide explanation for deviations between the point of maximum hardness and the point of minimum energy. It is also found that the dual descriptor plays a very important role in hardness equalization. PMID:23758354

Gázquez, José L; Vela, Alberto; Chattaraj, Pratim K

2013-06-01

42

Hard clam aquaculture is the largest and most valuable of the shellfish  

E-print Network

Hard clam aquaculture is the largest and most valuable of the shellfish aquaculture industries on the East Coast. It accounts for more than $50 million in economic value annually. Hard clams are bivalve or freshwater for an extend- ed period. Hard clams occur natural- ly all along the Atlantic coast from Nova

Florida, University of

43

Hard metal composition  

DOEpatents

A composition of matter having a Rockwell A hardness of at least 85 is formed from a precursor mixture comprising between 3 and 10 wt % boron carbide and the remainder a metal mixture comprising from 70 to 90% tungsten or molybdenum, with the remainder of the metal mixture comprising nickel and iron or a mixture thereof. The composition has a relatively low density of between 7 and 14 g/cc. The precursor is preferably hot pressed to yield a composition having greater than 100% of theoretical density.

Sheinberg, H.

1983-07-26

44

Hard metal composition  

DOEpatents

A composition of matter having a Rockwell A hardness of at least 85 is formed from a precursor mixture comprising between 3 and 10 weight percent boron carbide and the remainder a metal mixture comprising from 70 to 90 percent tungsten or molybdenum, with the remainder of the metal mixture comprising nickel and iron or a mixture thereof. The composition has a relatively low density of between 7 to 14 g/cc. The precursor is preferably hot pressed to yield a composition having greater than 100% of theoretical density.

Sheinberg, Haskell (Los Alamos, NM)

1986-01-01

45

Hard physics in PHENIX  

E-print Network

We review recent results on hard observables in p+p, d+A and A+A collisions obtained by the PHENIX experiment. Emphasis is put on those measurements that provide insight into the properties of hot QCD media expected to be created in nucleus-nucleus collisions at RHIC energies. Direct photon spectra, jet properties and heavy quarks production measured in p+p and d+Au collisions are compared to the same observables extracted in heavy ion collisions to find modifications due to the presence of hot QCD matter.

D. Peressounko; for the PHENIX collaboration

2005-12-08

46

Hardness of Materials- Introduction  

NSDL National Science Digital Library

This lesson plan from Edmonds Community College will serve as an excellent introduction to the hardness of materials. The module illustrates the differences in properties between different materials. Students will determine property differences between different types of materials, observe property differences between materials of the same class, measure, record and report their results and observe differences in results due to operator error. Student, instructor and course evaluation questions are included. This document will serve as a framework for instructors and may be downloaded in PDF format.

2012-10-12

47

Separating hard and soft scales in hard processes in a QCD plasma  

E-print Network

We present a picture of hard processes in a hot plasma in terms of the hard scale part of the process, where perturbative QCD should be applicable, and the soft scale part of the process, where we look to the AdS/CFT correspondence for guidance to possible strong effective coupling phenomena. In particular we estimate $\\hat{q}$, the transport coefficient, supposing that at soft scales partons in the plasma all cascade to small-$x$-values as indicated by strong coupling SYM theory.

A. H. Mueller

2008-05-20

48

Place Value  

NSDL National Science Digital Library

These activites cover place value of ones, tens, hundreds and thousands. Please complete the games in order. You must finish each game before going on to the next one. Game #1: Dinosaur Numbers (place value) Game #2: Shark Numbers (place value) Game #3: Place Value Golf (harder) ...

Christian, Mrs.

2007-03-21

49

Expected Value  

NSDL National Science Digital Library

This online, interactive lesson on expected value provides examples, exercises, and applets in which students will explore relationships between the expected value of real-valued random variables and the center of the distribution. Students will also examine how expected values can be used to measure spread and correlation.

Siegrist, Kyle

50

Effect of Water Hardness on Bioremoval of Arsenic and Nickel  

NASA Astrophysics Data System (ADS)

Laboratory experiments explored the effect of water hardness on the ability of Lemna m to sorb Arsenic and Nickel from water. System variables included the presence of hardness (100 mg/L as CaCO3), Arsenic (1.0 mg/L), Nickel (1.0 mg/L), and the aquatic plant Lemna m. Values were chosen to represent approximate values from drainage water in a sulfide mine. A four factor, two level factorial experimental design was used to determine the effect of each variable and the interactions between the variables. Results suggest no significant interaction between water hardness and the bioremoval of As or Ni. This finding suggests a useful alternative to chemical precipitation based removals which commonly must reduce water hardness before removing other contaminants.

Sternberg, S. P.

2008-12-01

51

Evaluation of mechanical properties of some glycine complexes  

NASA Astrophysics Data System (ADS)

The variation of Vickers hardness with load for (101) glycine zinc chloride (GZC), (001) glycine lithium sulphate (GLS), (001) triglycine sulphate (TGS) and (010) glycine phosphite (GPI) crystals was studied. From the cracks initiated along the corners of the indentation impression, crack lengths were measured and the fracture toughness value and brittle index number were determined. The hardness related parameters viz. yield strength and Young's modulus were also estimated. The anisotropic nature of the crystals was studied using Knoop indentation technique.

Nagaraju, D.; Raja Shekar, P. V.; Chandra, Ch. Sateesh; Rao, K. Kishan; Krishna, N. Gopi

2014-04-01

52

Evaluation of mechanical properties of some glycine complexes  

SciTech Connect

The variation of Vickers hardness with load for (101) glycine zinc chloride (GZC), (001) glycine lithium sulphate (GLS), (001) triglycine sulphate (TGS) and (010) glycine phosphite (GPI) crystals was studied. From the cracks initiated along the corners of the indentation impression, crack lengths were measured and the fracture toughness value and brittle index number were determined. The hardness related parameters viz. yield strength and Young’s modulus were also estimated. The anisotropic nature of the crystals was studied using Knoop indentation technique.

Nagaraju, D. [Department of Physics, PG Centre, Lal Bahadur College, Warangal - 506007 (India); Raja Shekar, P. V., E-mail: pvrsleo@gmail.com [Department of Physics, SR Engineering College, Warangal - 506371 (India); Chandra, Ch. Sateesh [Department of Physics, Kakatiya Institute of Technology and Sciences, Warangal - 506015 (India); Rao, K. Kishan; Krishna, N. Gopi [Department of Physics, Kakatiya University, Warangal - 506009 (India)

2014-04-24

53

Connectivity percolation in suspensions of hard platelets.  

PubMed

We present a study on connectivity percolation in suspensions of hard platelets by means of Monte Carlo simulation. We interpret our results using a contact-volume argument based on an effective single-particle cell model. It is commonly assumed that the percolation threshold of anisotropic objects scales as their inverse aspect ratio. While this rule has been shown to hold for rodlike particles, we find that for hard platelike particles the percolation threshold is nonmonotonic in the aspect ratio. It exhibits a shallow minimum at intermediate aspect ratios and then saturates to a constant value. This effect is caused by the isotropic-nematic transition preempting the percolation transition. Hence the common strategy to use highly anisotropic, conductive particles as fillers in composite materials in order to produce conduction at low filler concentration is expected to fail for platelike fillers such as graphene and graphite nanoplatelets. PMID:23005096

Mathew, Maneesh; Schilling, Tanja; Oettel, Martin

2012-06-01

54

Transport coefficients of hard sphere fluids  

NASA Astrophysics Data System (ADS)

New calculations have been made of the self-diffusion coefficient D, the shear viscosity ?s , the bulk viscosity ?b and thermal conductivity ? of the hard sphere fluid, using molecular dynamics (MD) computer simulation. A newly developed hard sphere MD scheme was used to model the hard sphere fluid over a wide range up to the glass transition (~0.57 packing fraction). System sizes of up to 32 000 hard spheres were considered. This set of transport coefficient data was combined with others taken from the literature to test a number of previously proposed analytical formulae for these quantities together with some new ones given here. Only the self-diffusion coefficient showed any substantial n dependence for N > 500 at equilibrium fluid densities ( ? < 0.494). D increased with N , especially at intermediate densities in the range ? ~ 0.3-0.35. The expression for the packing fraction dependence of D proposed by Speedy, R. J., 1987, Molec. Phys. , 62 , 509 was shown to fit these data well for N ~ 500 particle systems. We found that the packing fraction ? dependence of the two viscosities and thermal conductivity, generically denoted by X , were represented well by the simple formula X/X0 = 1/[1 -( ? / gr;1)]m within the equilibrium fluid range 0 < ? <0.493. This formula has two disposable parameters, ?1 and m, and X0 is the value of the property X in the limit of zero density. This expression has the same form as the Krieger-Dougherty formula (Kreiger, I. M., 1972,Adv. Colloid. Interface Sci. , 3, 111) which is used widely in the colloid literature to represent the packing fraction dependence of the Newtonian shear viscosity of monodisperse colloidal near-hard spheres. Of course, in the present case, X0 was the dilute gas transport coefficient of the pure liquid rather than the solvent viscosity. It was not possible to fit the transport coefficient normalized by their Enskog values with such a simple expression because these ratios are typically of order unity until quite high packing fractions and then diverge rapidly at higher values over a relatively narrow density range. At the maximum equilibrium fluid packing fraction ? = 0.494 for both the hard sphere fluid and the corresponding colloidal case a very similar value was found for ?s/?0~ 30-40, suggesting that the 'crowding' effects and their consequences for the dynamics in this region of the phase diagram in the two types of liquid have much in common. For the hard sphere by MD, D0/D ~ 11 at the same packing fraction, possibly indicating the contribution from 'hydrodynamic enhancement' of this transport coefficient, which is largely absent for the shear viscosity. Interestingly the comparable ratio for hard sphere colloids is the same.

Sigurgeirsson, H.; Heyes, D. M.

55

Measuring the Hardness of Minerals  

ERIC Educational Resources Information Center

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…

Bushby, Jessica

2005-01-01

56

MISTIC: Radiation hard ECRIS  

NASA Astrophysics Data System (ADS)

The ISAC RIB facility at TRIUMF utilizes up to 100 ?A from the 500 MeV H - cyclotron to produce RIB using the isotopic separation on line (ISOL) method. In the moment, we are mainly using a hot surface ion source and a laser ion source to produce our RIB. A FEBIAD ion source has been recently tested at ISAC, but these ion sources are not suitable for gaseous elements like N, O, F, Ne, … , A new type of ion source is then necessary. By combining a high frequency electromagnetic wave and a magnetic confinement, the ECRIS [R. Geller, Electron Cyclotron Resonance Ion Source and ECR Plasmas, Institute of Physics Publishing, Bristol, 1996], [1] (electron cyclotron resonance ion source) can produce high energy electrons essential for efficient ionization of those elements. To this end, a prototype ECRIS called MISTIC (monocharged ion source for TRIUMF and ISAC complex) has been built at TRIUMF using a design similar to the one developed at GANIL [GANIL (Grand Accélérateur National d'Ions Lourds), www.ganil.fr], [2] The high level radiation caused by the proximity to the target prevented us to use a conventional ECRIS. To achieve a radiation hard ion source, we used coils instead of permanent magnets to produce the magnetic confinement. Each coil is supplied by 1000 A-15 V power supply. The RF generator cover a frequency range from 2 to 8 GHz giving us all the versatility we need to characterize the ionization of the following elements: He, Ne, Ar, Kr, Xe, C, O, N, F. Isotopes of these elements are involved in star thermonuclear cycles and, consequently, very important for researches in nuclear astrophysics. Measures of efficiency, emittance and ionization time will be performed for each of those elements. Preliminary tests show that MISTIC is very stable over a large range of frequency, magnetic field and pressure.

Labrecque, F.; Lecesne, N.; Bricault, P.

2008-10-01

57

Anisotropic elasticity and abnormal Poisson's ratios in super-hard materials  

NASA Astrophysics Data System (ADS)

We theoretically investigated the variable mechanical properties such as Young's modulus, Poisson's ratios and compressibility in super-hard materials. Our tensorial analysis reveals that the mechanical properties of super-hard materials are strongly sensitive to the anisotropy index of materials. In sharp contrast to the traditional positive constant as thought before, the Poisson's ratio of super-hard materials could be unexpectedly negative, zero, or even positive with a value much larger than the isotropic upper limit of 0.5 along definite directions. Our results uncover a correlation between compressibility and hardness, which offer insights on the prediction of new super-hard materials.

Huang, Chuanwei; Li, Rongpeng; Chen, Lang

2014-12-01

58

Hardness variability in commercial technologies  

SciTech Connect

The radiation hardness of commercial Floating Gate 256K E{sup 2}PROMs from a single diffusion lot was observed to vary between 5 to 25 krad(Si) when irradiated at a low dose rate of 64 mrad(Si)/s. Additional variations in E{sup 2}PROM hardness were found to depend on bias condition and failure mode (i.e., inability to read or write the memory), as well as the foundry at which the part was manufactured. This variability is related to system requirements, and it is shown that hardness level and variability affect the allowable mode of operation for E{sup 2}PROMs in space applications. The radiation hardness of commercial 1-Mbit CMOS SRAMs from Micron, Hitachi, and Sony irradiated at 147 rad(Si)/s was approximately 12, 13, and 19 krad(Si), respectively. These failure levels appear to be related to increases in leakage current during irradiation. Hardness of SRAMs from each manufacturer varied by less than 20%, but differences between manufacturers are significant. The Qualified Manufacturer`s List approach to radiation hardness assurance is suggested as a way to reduce variability and to improve the hardness level of commercial technologies.

Shaneyfelt, M.R.; Winokur, P.S.; Meisenheimer, T.L.; Sexton, F.W.; Roeske, S.B.; Knoll, M.G. [Sandia National Labs., Albuquerque, NM (United States)] [Sandia National Labs., Albuquerque, NM (United States)

1994-12-01

59

Place Values  

NSDL National Science Digital Library

This site has explanatory lessons, interactive practice, and challenge games all dealing with place value. Includes information, practice, and games on place value of two, three, six and seven digit numbers and expandend notation for two, three, six, and seven digit numbers. Problems are randomly selected and students receive immediate feedback with the correct response. The bottom of each lesson page contains timed exercises.

AAA Math

2007-12-12

60

Hardness potential derivatives and their relation to Fukui indices.  

PubMed

A simple as well as easy to compute formalism of hardness potential (originally defined by Parr and Gazquez, J. Phys. Chem., 1993, 97, 3939) is presented. Use of hardness potential formally resolves the N-dependence problem of local hardness. However, the hardness potential cannot describe the intra as well as intermolecular reactivity sequence satisfactorily of some chemical systems. The corresponding electrophilic [?(+)h(k)] and nucleophilic [?(-)h(k)] variants of the hardness potential are also developed, which measure the reactivity toward a nucleophilic (i.e., Nu(-)) and an electrophilic (i.e., El(+)) reagent, respectively. Interestingly, these two variants of the hardness potential lead to the right and left derivatives of Fukui potential. The proposed reactivity descriptors correctly predict the expected reactivity trends in the chosen systems. It has also been illustrated that the values of the variants of hardness potential (or Fukui potential) at the atomic nucleus have the ability to explain the intramolecular reactivity of biologically active indole derivatives. The future scope of applications as well as limitations of the proposed descriptors is also highlighted. PMID:23175426

Saha, Soumen; Bhattacharjee, Rituparna; Roy, Ram Kinkar

2013-03-30

61

Hard Spheres Monte Carlo Model  

NSDL National Science Digital Library

The Hard Sphere Monte Carlo Model performs canonical Monte Carlo simulations of 256 or 500 hard spheres covering the fluid and solid states. The results are analysed through the radial distributions functions from which the equation of state (EOS) is estimated. This is done by fitting a polynomial to the radial distribution functions in order to exrapolate them to the hard spheres distance of contact. The consistency of the simulations is assessed by the errors of the predicted compressibility factors relatively to the accurate EOS reported by Wu and Sadus. The Hard Sphere Monte Carlo Model was developed using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the jar file will run the program if Java is installed. You can modify this simulation if you have EJS installed by right-clicking within the map and selecting "Open Ejs Model" from the pop-up menu item.

Fernandes, Fernando S.; Freitas, Filomena

2013-02-20

62

Hope in Hard Times  

PubMed Central

In the face of challenging times, advocates for women and their families in maternal-child health care continue to promote evidence-based and mother-/baby-friendly care. What qualities allow childbirth educators, doulas, nurses, and perinatal care providers to keep going even when the health-care practices around them often do not match their values? This editorial explores the impact of recent trends in which increasing utilization of elective technology in maternity care may affect the individual commitment of childbirth advocates. Borrowing from research on successful advocates in other fields, the author speculates on both why and how childbirth advocates sustain commitment and how “we will prevail.” PMID:19119328

Leslie, Mayri Sagady

2008-01-01

63

Hard-phase engineering in hard/soft nanocomposite magnets  

NASA Astrophysics Data System (ADS)

Bulk SmCo/Fe(Co) based hard/soft nanocomposite magnets with different hard phases (1:5, 2:17, 2:7 and 1:3 types) were fabricated by high-energy ball-milling followed by a warm compaction process. Microstructural studies revealed a homogeneous distribution of bcc-Fe(Co) phase in the matrix of hard magnetic Sm-Co phase with grain size ?20 nm after severe plastic deformation and compaction. The small grain size leads to effective inter-phase exchange coupling as shown by the single-phase-like demagnetization behavior with enhanced remanence and energy product. Among the different hard phases investigated, it was found that the Sm2Co7-based nanocomposites can incorporate a higher soft phase content, and thus a larger reduction in rare-earth content compared with the 2:17, 1:5 and 1:3 phase-based nanocomposite with similar properties. (BH)max up to 17.6 MGOe was obtained for isotropic Sm2Co7/FeCo nanocomposite magnets with 40 wt% of the soft phase which is about 300% higher than the single-phase counterpart prepared under the same conditions. The results show that hard-phase engineering in nanocomposite magnets is an alternative approach to fabrication of high-strength nanocomposite magnets with reduced rare-earth content.

Poudyal, Narayan; Rong, Chuanbing; Vuong Nguyen, Van; Liu, J. Ping

2014-03-01

64

Mechanical properties of synthetic type IIa diamond crystal  

Microsoft Academic Search

The mechanical behavior of synthetic type IIa diamond has been investigated by the Knoop hardness measurement and observation of the cleavage surfaces. It was clarified that the Knoop hardness in (100)?100? of synthetic diamonds increases with decreasing of the nitrogen impurities concentration, and that the synthetic type IIa diamond, having few nitrogen impurities, has the highest hardness of synthetic diamonds.

H. Sumiya; N. Toda; S. Satoh

1997-01-01

65

Crop Values  

NSDL National Science Digital Library

While economic data on crop values are strictly commercial/ agricultural summaries, they can be useful as surrogate indices of land use/ cover change, or in estimating food subsidies (e.g. waste grain) for wildlife. Posted by the US Department of Agriculture (USDA) Economics and Statistics System at Cornell University, the site contains the "annual marketing year average prices and value of production of principal crops". Principal crops include barley (all, feed, and malting), hay, oats, rye, wheat (all, winter, durum, and other spring), upland and American-pima cotton and cottonseed, corn, dry beans, flaxseed, peanuts, sorghum, soybeans, sunflowers, and rice. These data are provided by the National Agricultural Statistics Service (USDA).

66

Value Added  

ERIC Educational Resources Information Center

This article profiles retiring values teacher Gene Doxey and describes his foundational contributions to the students of California's Ramona Unified School District. Every one of the Ramona Unified School District's 7,200 students is eventually funneled through Doxey's Contemporary Issues class, a required rite of passage between elementary school…

Welch, Matt

2004-01-01

67

Student Values.  

ERIC Educational Resources Information Center

This study examines the social, political, economic, and cultural values of students at Northern Michigan University by using a College Student Questionnaire (CSQ) administered to a stratified random sample of full-time undergraduates. The variables were: sex, class, and residence. The CSQ consisted of 200 multiple-choice questions designed to…

Stordahl, Kalmer E.

68

Expected Value  

NSDL National Science Digital Library

In this activity, students will use the random integer command on their graphing calculators to simulate rolling a die. They will then use operations on lists to analyze the probability of rolling the first 1 on the 1st roll, 2nd roll, and so on and finally find the expected value. Teacher notes explain in detail how to perform these actions on the graphing calculator.

2012-08-30

69

Value creation  

SciTech Connect

In 1994 a group of gathering and processing companies commissioned Sterling Consulting Group of Houston Texas to conduct a benchmarking study to analyze the industry and measure performance of individual companies in a manner unique from previous cost oriented benchmarking studies. The study, Eagles View, focused on strategic issues that effect performance. The study used four types of benchmarking: value, operational, function, and process benchmarking. The paper describes the study methodology.

Roussel, D.C. [Cyclone Development, Houston, TX (United States)

1995-11-01

70

Hard Work and Hard Data: Getting Our Message Out.  

ERIC Educational Resources Information Center

Unless questions about student performance and student retention can be answered and unless educators are proactive in finding and publicizing such information, basic writing programs cannot determine if what they are doing is working. Hard data, especially from underrepresented groups, is needed to support these programs. At Arizona State…

Glau, Gregory R.

71

Biology of the hard clam Hard clams of the genus Mercenaria  

E-print Network

Biology of the hard clam Hard clams of the genus Mercenaria are found from the Gulf of St. Lawrence of the general- izations may apply to all hard clams. The hard clam is rarely found where salinities average less than 20 parts per thousand (ppt). Hard clams occu- py intertidal and subtidal habitats, where

Florida, University of

72

Hard scattering in ?p interactions  

NASA Astrophysics Data System (ADS)

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 processess as predicted by QCD.

Ahmed, T.; Andreev, V.; Andrieu, B.; Arpagaus, M.; Babayev, A.; Bärwolff, H.; Ban, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Beck, G. A.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Berthon, U.; 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.; Bürger, J.; Büsser, 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.; Düllmann, D.; Dünger, 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.; Ference, J.; Ferrarotto, F.; Flauger, W.; Fleischer, M.; Flügge, G.; Fomenko, A.; Fominykh, 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.; Grässler, H.; Grässler, R.; Greenshaw, T.; Greif, H.; Grindhammer, G.; Gruber, C.; Haack, J.; 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.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladky, J.; Hoeger, K. C.; Huet, Ph.; Hufnagel, H.; Huot, N.; Ibbotson, M.; Jabiol, M. A.; Jacholkowska, A.; Jacobson, C.; Jaffre, M.; Jönsson, L.; Johannsen, K.; Johnson, D.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kasarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kurca, T.; Kurzhöfer, J.; Kuznik, B.; Lander, R.; Landon, M. P. J.; Langkau, R.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Lenhardt, U.; Leuschner, A.; Leverenz, C.; Levin, D.; Levonian, S.; Ley, Ch.; Lindström, G.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marks, J.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Milone, V.; Monnier, E.; Moreau, F.; Moreels, J.; Morris, J. V.; Morton, J. M.; Müller, K.; Murin, P.; Murray, S. A.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Newton, D.; Nguyen, H. K.; Niebergall, F.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Orenstein, S.; Ould-Saada, F.; Pascaud, C.; Patel, G. D.; Peppel, E.; Peters, S.; Phillips, H. T.; Phillips, J. P.; Pichler, Ch.; Pilgram, W.; Pitzl, D.; Prosi, R.; Raupach, F.; Rauschnabel, K.; Reimer, P.; Ribarics, P.; Riech, V.; Riedlberger, J.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Royon, C.; Rudowicz, M.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Ryseck, E.; Sacton, J.; Sahlmann, N.; Sanchez, E.; Sankey, D. P.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schmitz, W.; Schröder, V.; Schulz, M.; Schwind, A.; Scobel, W.; Seehausen, U.; Sell, R.; Seman, M.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Smolik, L.; Soloviev, Y.; Spitzer, H.; Staroba, P.; Steenbock, M.; Steffen, P.; Steinberg, R.; Steiner, H.; Stella, B.; Stephens, K.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Taylor, R. E.; Thompson, G.; Thompson, R. J.; Tichomirov, I.; Trenkel, C.; Truöl, P.; Tchernyshov, V.; Turnau, J.; Tutas, J.; Urban, L.; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; VanEsch, P.; Vartapetian, A.; Vasdik, J.; Vecko, M.; Verrecchia, P.; Vick, R.; Villet, G.; Vogel, E.; Wacker, K.; Walker, I. W.; Walther, A.; Weber, G.; Wegener, D.; Wegner, A.

1992-12-01

73

Is Carbon Hard or Soft?  

NSDL National Science Digital Library

The representation shows differences in the arrangement of carbon atoms that make up diamonds and graphite. Through text and pictures, the resource describes the difference in arrangement of two different carbon allotropes. The text relates the differences in arrangements to differences in the hardness (properties) of the materials.

74

Hard and soft multifractal processes  

Microsoft Academic Search

We show that multifractal notions encompass a wider variety of phenomena than often believed. Ranked by increasing highest order of singularities we have geometric, then microcanonical and finally canonical multifractals. They are respectively localized and ``calm'', delocalized and ``calm'', and delocalized and ``wild''. Canonical multifractals may also involve rare violent (``hard'') singularities which cause high order statistical moments to diverge.

D. Schertzer; S. Lovejoy

1992-01-01

75

FATIGUE OF BIOMATERIALS: HARD TISSUES  

PubMed Central

The fatigue and fracture behavior of hard tissues are topics of considerable interest today. This special group of organic materials comprises the highly mineralized and load-bearing tissues of the human body, and includes bone, cementum, dentin and enamel. An understanding of their fatigue behavior and the influence of loading conditions and physiological factors (e.g. aging and disease) on the mechanisms of degradation are essential for achieving lifelong health. But there is much more to this topic than the immediate medical issues. There are many challenges to characterizing the fatigue behavior of hard tissues, much of which is attributed to size constraints and the complexity of their microstructure. The relative importance of the constituents on the type and distribution of defects, rate of coalescence, and their contributions to the initiation and growth of cracks, are formidable topics that have not reached maturity. Hard tissues also provide a medium for learning and a source of inspiration in the design of new microstructures for engineering materials. This article briefly reviews fatigue of hard tissues with shared emphasis on current understanding, the challenges and the unanswered questions. PMID:20563239

Arola, D.; Bajaj, D.; Ivancik, J.; Majd, H.; Zhang, D.

2009-01-01

76

Magnon softening in exchange-coupled hard-soft nanocomposites  

NASA Astrophysics Data System (ADS)

We study spin excitations of the fully aligned state for three-dimensional nanocomposites of exchange coupled hard (SmFeN) and soft (FeCo) phases. The dipolar interaction lowers the magnon energy and controls the spin wave gap at k = 0, which closes when the amount of soft phase exceeds a critical value. With the addition of soft phase or increasing temperature the system moves to another ground state characterized by a tilting of the magnetization at the boundaries between spins of the hard and the soft phases.

Belemuk, A. M.; Chui, S. T.

2013-03-01

77

Contact theorems for anisotropic fluids near a hard wall.  

PubMed

In this paper, from the Born-Green-Yvon equation, we formulate a general expression for the contact value of the singlet distribution function for anisotropic fluids near a hard wall. This expression consists of two separate contributions. One is related to the bulk partial pressure for a given orientation of the molecules. The second is related to the anchoring phenomena and is characterized by the direct interaction between the molecules and the wall. Given this relation, we formulate the contact theorems for the density and order parameter profiles. The results are illustrated by the case of a nematic fluid near a hard wall. PMID:25573576

Holovko, M; di Caprio, D

2015-01-01

78

Contact theorems for anisotropic fluids near a hard wall  

NASA Astrophysics Data System (ADS)

In this paper, from the Born-Green-Yvon equation, we formulate a general expression for the contact value of the singlet distribution function for anisotropic fluids near a hard wall. This expression consists of two separate contributions. One is related to the bulk partial pressure for a given orientation of the molecules. The second is related to the anchoring phenomena and is characterized by the direct interaction between the molecules and the wall. Given this relation, we formulate the contact theorems for the density and order parameter profiles. The results are illustrated by the case of a nematic fluid near a hard wall.

Holovko, M.; di Caprio, D.

2015-01-01

79

Charpy Impact Energy and Microindentation Hardness of 60-NITINOL  

NASA Technical Reports Server (NTRS)

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.

Stanford, Malcolm K.

2012-01-01

80

Valuing vaccination  

PubMed Central

Vaccination has led to remarkable health gains over the last century. However, large coverage gaps remain, which will require significant financial resources and political will to address. In recent years, a compelling line of inquiry has established the economic benefits of health, at both the individual and aggregate levels. Most existing economic evaluations of particular health interventions fail to account for this new research, leading to potentially sizable undervaluation of those interventions. In line with this new research, we set forth a framework for conceptualizing the full benefits of vaccination, including avoided medical care costs, outcome-related productivity gains, behavior-related productivity gains, community health externalities, community economic externalities, and the value of risk reduction and pure health gains. We also review literature highlighting the magnitude of these sources of benefit for different vaccinations. Finally, we outline the steps that need to be taken to implement a broad-approach economic evaluation and discuss the implications of this work for research, policy, and resource allocation for vaccine development and delivery. PMID:25136129

Bärnighausen, Till; Bloom, David E.; Cafiero-Fonseca, Elizabeth T.; O’Brien, Jennifer Carroll

2014-01-01

81

Ultrasonic material hardness depth measurement  

DOEpatents

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. 12 figs.

Good, M.S.; Schuster, G.J.; Skorpik, J.R.

1997-07-08

82

Weld cladding of hard surfaces  

NASA Astrophysics Data System (ADS)

A literature study about clad welding of hard surfaces on steel is performed. The purpose was to see what kind of methods are mainly used, and particular attention is paid to clad welding of rolls. The main impression from this study is that several methods are in use. Some of these must be considered as 'too exotic' for the aim of the program, such as laser build-up welding. However, clad welding of hard surfaces to rolls is widely used around the world, and there is no need for particularly advanced welding methods to perform the work. The welding consumables and the way the welding is carried out is of more important character. The report will give some comments to this, and hopefully will give a short review of the current technology in this field.

Habrekke, T.

1993-02-01

83

Hard Disk PVT System Model  

NSDL National Science Digital Library

The Hard Disk PVT System simulates a two-dimensional system of particles confined between a thermal reservoir and a piston. This computer model is designed to study the equation of state for hard disks without other interactions. Slow-moving particles are color-coded as blue and fast particles are color-coded as yellow. Users can set the initial particle energy, the initial particle separation, and the thermal reservoir temperature Tr. The thermal conductivity parameter ? determines the probability that a collision with the thermal wall will affect (thermalize) the colliding particle. If the conductivity is one, the particle velocity after a reservoir collision is set according to Maxwell-Boltzmann statistics. If the conductivity is zero, all reservoir collisions are elastic and the internal energy E of the system is conserved.   Particles in this model have unit mass and interact through contact forces. Collision times are computed analytically because particles and pistons move with constant velocity between collisions. The time evolution algorithm advances the particle and piston positions from collision to collision until the requested time step ?t is achieved. The time evolution is then paused, data is accumulated, and the screen is redrawn. The Hard Disk PVT model is a supplemental simulation for the article "Pressure Oscillations in Adiabatic Compression" by Roland Stout in The Physics Teacher 49(5), 280-281 (2011) and has been approved by the author and The Physics Teacher editor. The model was developed using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_stp_hd_HardDiskPVTSystem.jar file will run the program if Java is installed.

Christian, Wolfgang

2011-03-12

84

The Relationship Between Grain Hardness, Dough Mixing Parameters and Bread-Making Quality in Winter Wheat  

PubMed Central

The influence of grain hardness, determined by using molecular markers and physical methods (near-infrared (NIR) technique and particle size index—PSI) on dough characteristics, which in turn were determined with the use of a farinograph and reomixer, as well as bread-making properties were studied. The material covered 24 winter wheat genotypes differing in grain hardness. The field experiment was conducted at standard and increased levels of nitrogen fertilization. Results of molecular analyses were in agreement with those obtained by the use of physical methods for soft-grained lines. Some lines classified as hard (by physical methods) appeared to have the wild-type Pina and Pinb alleles, similar to soft lines. Differences in dough and bread-making properties between lines classified as hard and soft on the basis of molecular data appeared to be of less significance than the differences between lines classified as hard and soft on the basis of physical analyses of grain texture. Values of relative grain hardness at the increased nitrogen fertilization level were significantly higher. At both fertilization levels the NIR parameter determining grain hardness was significantly positively correlated with the wet gluten and sedimentation values, with most of the rheological parameters and bread yield. Values of this parameter correlated with quality characteristics in a higher degree than values of particle size index. PMID:22605973

Salmanowicz, Boles?aw P.; Adamski, Tadeusz; Surma, Maria; Kaczmarek, Zygmunt; Karolina, Krystkowiak; Kuczy?ska, Anetta; Banaszak, Zofia; ?ugowska, Bogus?awa; Majcher, Ma?gorzata; Obuchowski, Wiktor

2012-01-01

85

Hard?to?cook phenomenon in legumes  

Microsoft Academic Search

Hard?to?cook legumes (HTCL) have been observed for centuries. Different types of HTCL are recognized in freshly harvested crops or are developed during storage. Two types of hard shell, which is due to seed coat impermeability to water, are identified: (1) the reversible hard shell that occurs in freshly harvested seeds and disappear during storage; (2) the other type is the

1992-01-01

86

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2010 CFR

... 3 2010-01-01 2010-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture...Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard at the end of the prescribed test because they...

2010-01-01

87

30 CFR 57.15002 - Hard hats.  

Code of Federal Regulations, 2010 CFR

...1 2010-07-01 2010-07-01 false Hard hats. 57.15002 Section 57.15002 Mineral...Protection Surface and Underground § 57.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or plant where...

2010-07-01

88

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Hard seed. 201.30 Section 201.30 Agriculture...REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed, if any is present, for any seed...

2010-01-01

89

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Hard seed. 201.21 Section 201.21 Agriculture... Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard seed, if any is present, for any seed...

2010-01-01

90

30 CFR 56.15002 - Hard hats.  

Code of Federal Regulations, 2010 CFR

...1 2010-07-01 2010-07-01 false Hard hats. 56.15002 Section 56.15002 Mineral...MINES Personal Protection § 56.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or plant where...

2010-07-01

91

Artificially soft and hard surfaces in electromagnetics  

Microsoft Academic Search

A transversely corrugated surface as used in corrugated horn antennas represents a soft boundary. A hard boundary is made by using longitudinal corrugations filled with dielectric material. The concept of soft and hard surfaces is treated in detail, considering different geometries. It is shown that both the hard and soft boundaries have the advantage of a polarization-independent reflection coefficient for

Per-Simon Kildal

1990-01-01

92

Online Diagnosis of Hard Faults in Microprocessors  

E-print Network

Online Diagnosis of Hard Faults in Microprocessors FRED A. BOWER Duke University and IBM Systems Paper: Fred A. Bower, Daniel J. Sorin, and Sule Ozev. "A Mechanism for Online Diagnosis of Hard Faults. Online diagnosis of hard faults in microprocessors. Architec. Code Optim. 4, 2, Article 8 (June 2007),

Sorin, Daniel J.

93

Warren G. Harding and the Press.  

ERIC Educational Resources Information Center

There are many parallels between the Richard M. Nixon administration and Warren G. Harding's term: both Republicans, both touched by scandal, and both having a unique relationship with the press. But in Harding's case the relationship was a positive one. One of Harding's first official acts as president was to restore the regular White House news…

Whitaker, W. Richard

94

Hard body amphiphiles at a hard wall JOSEPH M. BRADER1y  

E-print Network

Hard body amphiphiles at a hard wall JOSEPH M. BRADER1y , CHRISTIAN VON FERBER2 and MATTHIAS 2003) We investigate the structure of amphiphilic molecules exposed to a substrate that is modelled by a hard wall. Our simple model amphiphiles consist of a hard sphere head group to which a vanishingly thin

Ott, Albrecht

95

The Hard Problem of Cooperation  

PubMed Central

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. PMID:22792282

Eriksson, Kimmo; Strimling, Pontus

2012-01-01

96

Hard Scattering Studies at Jlab  

SciTech Connect

We present current activities and future prospects for studies of hard scattering processes using the CLAS detector and the CEBAF polarized electron beam. Kinematic dependences of single and double spin asymmetries have been measured in a wide kinematic range at CLAS with a polarized NH{sub 3} and unpolarized liquid hydrogen targets. It has been shown that the data are consistent with factorization and observed target and beam asymmetries are in good agreement with measurements performed at higher energies, suggesting that the high energy-description of the semi-inclusive DIS process can be extended to the moderate energies of JLab measurements.

Harutyun Avagyan; Peter Bosted; Volker Burkert; Latifa Elouadrhiri

2005-09-01

97

Hard and fragile holmium-based bulk metallic glasses  

SciTech Connect

A family of holmium-based bulk metallic glasses (BMGs) with high glass-forming ability is obtained. The Ho-based BMGs exhibit much larger elastic moduli and high thermal stability in contrast to other known rare-earth (RE)-based BMGs. In particular, the BMGs show a large value of fragility. It is expected that the hard RE-based glasses with high glass-forming ability and fragile behaviors make them the appropriate candidate for glass transition study.

Luo, Q.; Zhao, D.Q.; Pan, M.X.; Wang, R.J.; Wang, W.H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China)

2006-05-01

98

30 CFR 77.1710-1 - Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced...Miscellaneous § 77.1710-1 Distinctively colored hard hats or hard caps; identification for newly...

2010-07-01

99

30 CFR 75.1720-1 - Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced...Miscellaneous § 75.1720-1 Distinctively colored hard hats, or hard caps; identification for newly...

2010-07-01

100

Measurements of the hard-x-ray reflectivity of iridium  

SciTech Connect

In connection with the design of a hard-x-ray telescope for the Constellation X-Ray Observatory we measured the reflectivity of an iridium-coated zerodur substrate as a function of angle at 55, 60, 70, and 80 keV at the National Synchrotron Light Source of Brookhaven National Laboratory. The optical constants were derived from the reflectivity data. The real component of the index of refraction is in excellent agreement with theoretical values at all four energies. However, the imaginary component, which is related to the mass attenuation coefficient, is 50% to 70% larger at 55, 60, and 70 keV than theoretical values.

Romaine, S.; Bruni, R.; Gorenstein, P.; Zhong, Z

2007-01-10

101

Development of radiation hard scintillators  

SciTech Connect

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

Markley, F.; Woods, D.; Pla-Dalmau, A.; Foster, G. (Fermi National Accelerator Lab., Batavia, IL (United States)); Blackburn, R. (Michigan Univ., Nuclear Reactor Lab., Ann Arbor, MI (United States))

1992-05-01

102

Development of radiation hard scintillators  

NASA Astrophysics Data System (ADS)

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

Markley, F.; Woods, D.; Pla-Dalmau, A.; Foster, G.; Blackburn, R.

1993-01-01

103

Water hardness control by detergent builders  

Microsoft Academic Search

Commercial detergent additives to control water hardness are of three main types, sequestrant, precipitant or ion-exchange\\u000a builders. These builders lower the free hardness ion (Ca+2, Mg+2) concentration in a wash system by different mechanisms. An electrometric experimental method was used to evaluate the relative\\u000a water hardness control performances of different builder-types under conditions closely simulating those of detergent’s end-use.\\u000a Experimental

M. K. Nagarajan; H. L. Paine

1984-01-01

104

Values in Education and Education in Values.  

ERIC Educational Resources Information Center

The major purpose of this book is to set out some of the key issues and debates relating to the importance of values in education and of education in values. After an introductory chapter about the concept of values and values education, part 1 provides a variety of perspectives on the values that underpin contemporary education. The introduction…

Halstead, J. Mark, Ed.; Taylor, Monica J., Ed.

105

Electromagnetic Scattering from Foliage Camouflaged Hard Targets,  

E-print Network

Electromagnetic Scattering from Foliage Camouflaged Hard Targets, in VHF-band Mojtaba Dehmollaian. Then using this formulation, and single scattering theory the backscattered field from a camouflaged complex

Sarabandi, Kamal

106

Electronic, elastic properties and hardness of the novel tetragonal silicon  

NASA Astrophysics Data System (ADS)

Silicon is an important material for technical applications. Recently, a long-puzzling metastable phase of silicon (T12-Si) has been theoretically identified. In this work, we used first-principles calculations to study the electronic and elastic properties and the hardness of this new silicon allotrope to enrich the relevant information. These properties of cubic Si ( c-Si) were also calculated for comparison. The results show that the T12-Si is mechanically anisotropic and has a lower bulk modulus and shear modulus than c-Si. Its theoretical hardness is 10.3 GPa, smaller than the value of 13.5 GPa for c-Si. Analyses of the electronic properties reveal that T12-Si is an indirect band gap crystal with a gap value of 0.69 eV, making it a promising semiconductor for future technical applications and that covalent sp 3-hybridization is the main interaction in this crystal. The reason the calculated hardnesses of c-Si and T12-Si are rather small compared to that of diamond is also discussed.

Hao, Xi-Ping; Cui, Hong-Ling

2014-07-01

107

Influence of design variables on radiation hardness of silicon MINP solar cells  

NASA Technical Reports Server (NTRS)

Metal-insulator-N/P silicon (MINP) solar cells were fabricated using different substrate resistivity values, different N-layer designs, and different I-layer designs. A shallow junction into an 0.3 ohm-cm substrate gave best efficiency whereas a deeper junction into a 1 to 4 ohm-cm substrate gave improved radiation hardness. I-layer design variation did little to influence radiation hardness.

Anderson, W. A.; Solaun, S.; Rao, B. B.; Banerjee, S.

1985-01-01

108

Estimating the unconfined compressive strength of intact rocks from Equotip hardness  

Microsoft Academic Search

In order to utilize the Equotip hardness tester, originally developed in the field of metallic engineering, as an indirect\\u000a method to predict the unconfined compressive strength (UCS) of rock, laboratory tests were undertaken to establish the UCS,\\u000a Equotip hardness (L-value) and porosity of nine rock types. Using existing data from Verwaal and Mulder (Int J Rock Mech Min Sci Geomech

Hisashi Aoki; Yukinori Matsukura

2008-01-01

109

TOXICITY OF COPPER TO CUTTHROAT TROUT ('SALMO CLARKI') UNDER DIFFERENT CONDITIONS OF ALKALINITY, PH, AND HARDNESS  

EPA Science Inventory

Median lethal concentration (96-h LC50) values for acute copper toxicity to 3-10 g cutthroat trout (Salmo clarki) have been determined for nine different combinations of alkalinity, hardness, and pH. Equilibrium calculations were performed on the copper LC50 values; seven differe...

110

Successes and failures with hard probes  

E-print Network

The two major pillars of searches for the Quark Gluon Plasma have been: J/$\\Psi$ suppression, proposed in 1986, and observed at both SPS fixed target energies and at RHIC; and, more recently, the suppression of $\\pi^0$ with $p_T\\geq 3$ GeV/c by a factor $\\sim 5$ in Au+Au central collisions, observed at RHIC in 2001, which had been predicted in advance as a consequence of Landau-Pomeranchuck-Migdal coherent (gluon) bremsstrahlung by the outgoing hard-scattered partons traversing the medium. However, new effects were discovered and the quality of the measurements greatly improved so that the clarity of the original explanations has become obscured. For instance: J/$\\Psi$ suppression is the same at SpS and RHIC. Is it the QGP, comovers, something else? QCD provides beautiful explanations of $\\pi^0$ and direct $\\gamma$ measurements in p-p collisions but precision fits of the best theories of $\\pi^0$ suppression barely agree with the Au+Au data. Better data are needed for $10< p_T <20$ GeV/c, systematic errors are needed in theory calculations, the values of parameters of the medium such as $\\mean{\\hat{q}}$ derived from precision fits are the subject of controversy. ... These and other issues will be discussed with a view to identify which conclusions are firm and where further progress towards real understanding is required.

M. J. Tannenbaum

2008-11-04

111

Consciousness in Robots: The Hard Problem and Some Less Hard Problems  

E-print Network

1 Consciousness in Robots: The Hard Problem and Some Less Hard Problems (Extended Version discuss important func- tions that can be served by consciousness in autonomous robots. We distinguish intrinsic intentionality from consciousness, but argue it is also important. Fi- nally we explore the Hard

Wang, Xiaorui "Ray"

112

Magnon softening in exchange-coupled hard-soft nanocomposites  

NASA Astrophysics Data System (ADS)

We study spin excitations of the fully aligned state for three-dimensional nanocomposites of exchange coupled hard (SmFeN) and soft (FeCo) phases. When the amount of soft phase is increased the energy of low-lying spin excitation is considerably softened and contains a contribution proportional to the anisotropy constant of the soft phase. The dipolar interaction further lowers the magnon energy and controls the spin wave gap at k= 0, which closes when the amount of soft phase exceeds a critical value. With the addition of soft phase or increasing the temperature the system moves to another ground state characterized by a magnetization mismatch between spins of hard and soft phases.

Belemuk, Alexander; Tat Chui, Siu

2013-03-01

113

Systematics of compression of hard materials  

Microsoft Academic Search

Hard materials have the remarkable property that relatively little internal energy of shock compression is deposited as temperature and associated thermal pressure. As a result, the Hugoniot curve is nearly coincident with the 0-K isotherm. Since the isentrope is intermediate between isotherm and Hugoniot, all three curves of a given hard material are nearly coincident. Published data for diamond and

W J Nellis

2008-01-01

114

Hard Spring Wheat Technical Committee 2009 Crop  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thirteen hard spring wheat lines that were developed by breeders throughout the spring wheat region of the U. S. were grown at up to five locations in 2009 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Samples of wheat were milled at the USDA Hard Red ...

115

Matrix of Hard and Soft Skills  

NSDL National Science Digital Library

This document was developed by Access Tech Careers to support successful course completion for students with learning disabilities. This matrix displays intersections between hard skills, including reading, writing, oral communication, and math, with soft skills, including critical thinking, teamwork, professionalism, and adaptability. It can help instructors integrate hard and soft skills in course planning.

116

Classic Nintendo Games are (Computationally) Hard  

E-print Network

video games [1,4,5,6], but the most well-known classic Nintendo games have yet to be included amongClassic Nintendo Games are (Computationally) Hard Greg Aloupis1 , Erik D. Demaine2 , Alan Guo2, Canada, viglietta@gmail.com Abstract. We prove NP-hardness results for five of Nintendo's largest video

Demaine, Erik

117

Hard Metal Alveolitis Accompanied by Rheumatoid Arthritis  

Microsoft Academic Search

Hard metal lung diseases (HML) are rare, and complex to diagnose. We describe the case of a patient with allergic alveolitis accompanied by rheumatoid arthritis. A sharpener of hard metal by trade, our patient was a 45-year-old, nonsmoking Caucasian female who experienced symptoms of cough and phlegm, and dyspnea on exertion. Preliminary lung findings were inspiratory rales in both basal

Paula A. Hahtola; Ritva E. Järvenpää; Kari Lounatmaa; Jorma J. Mattila; Immo Rantala; Jukka A. Uitti; Seppo Sutinen

2000-01-01

118

Monodispersed hard carbon spherules with uniform nanopores  

Microsoft Academic Search

Hard carbon with perfect spherical morphology was prepared for the first time by a hydrothermal method. It has controllable monodispersed particle size and a smooth surface. Transmission electron microscopy shows that there are a large quantity of uniform nanopores of about 0.4 nm in diameter and only very few parallel graphene sheets exist within the spherules. This hard carbon material

Qing Wang; Hong Li; Liquan Chen; Xuejie Huang

2001-01-01

119

Preliminary Health Assessment of Cultured Hard Clams,  

E-print Network

Preliminary Health Assessment of Cultured Hard Clams, Mercenaria mercenaria, in Florida Ruth for cultured hard clams in Floridaclams in Florida #12;Health Monitoring Program: SamplingSampling · 60 animals Density lease area Indian River Aquaculture Use Zone represent the majority of the clam production Sand

Florida, University of

120

HARD CLAM HYBRIDS FOR FLORIDAAQUACULTURE: HATCHERY CULTURE  

E-print Network

HARD CLAM HYBRIDS FOR FLORIDAAQUACULTURE: HATCHERY CULTURE John Scarpa: Harbor Branch Oceanographic and Aquatic Sciences, Gainesville, FL 32653 Introduction The hard clam (Mercenaria mercenaria notata) is the dominant molluscan species in Florida aquaculture (~$10 million in 2005). Clam production in Florida has

Florida, University of

121

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2013 CFR

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [24 FR 3953, May 15,...

2013-01-01

122

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2013 CFR

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [32 FR 12779, Sept. 6,...

2013-01-01

123

7 CFR 201.30 - Hard seed.  

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [32 FR 12779, Sept. 6,...

2014-01-01

124

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2012 CFR

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [24 FR 3953, May 15,...

2012-01-01

125

7 CFR 201.21 - Hard seed.  

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [24 FR 3953, May 15,...

2014-01-01

126

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2012 CFR

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [32 FR 12779, Sept. 6,...

2012-01-01

127

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2011 CFR

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [24 FR 3953, May 15,...

2011-01-01

128

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2011 CFR

...percentage of hard seed, if any is present, for any seed required to be labeled as to the percentage of germination, and the percentage of hard seed shall not be included as part of the germination percentage. [32 FR 12779, Sept. 6,...

2011-01-01

129

Solving Hard ASP Programs Efficiently Wolfgang Faber  

E-print Network

Solving Hard ASP Programs Efficiently Wolfgang Faber and Francesco Ricca Department of Mathematics research on answer set programming (ASP) systems, has mainly focused on solving NP problems more. In this paper we focus on improving the evaluation of P 2 /P 2 -hard ASP programs. To this end, we define a new

Faber, Wolfgang

130

MAKING JAVA HARD REALTIME Peter Puschner  

E-print Network

MAKING JAVA HARD REAL­TIME Peter Puschner Institut fË?ur Technische Informatik Technische Universit,andyg@cs.york.ac.uk ABSTRACT Due to its portability and security the Java program­ ming language has become very popular. Standard Java is however not suited for programming hard real­time sys­ tems. To overcome this limitation

131

New approaches to hard bubble suppression  

NASA Technical Reports Server (NTRS)

Description of a new double-layer method for the suppression of hard bubbles that is more versatile than previously reported suppression techniques. It is shown that it may be possible to prevent hard bubble generation without recourse to exchange coupling of multilayer films.

Henry, R. D.; Besser, P. J.; Warren, R. G.; Whitcomb, E. C.

1973-01-01

132

Monte Carlo computer simulation of sedimentation of charged hard spherocylinders.  

PubMed

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/? = 5, where L and ? 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/? = 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, ? = (mg?)/(e(2)/D?), where m is the mass per particle, e is the electron's charge and g is the gravitational acceleration value. A semi-infinite simulation cell was used with dimensions Lx ? Ly and Lz = 5Lx, where Lx, Ly, and Lz are the box dimensions in Cartesian coordinates, and the gravitational force acts along the z-direction. Sedimentation effects were studied by looking at every layer formed by the CHSC along the gravitational field. By increasing ?, 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. PMID:25084954

Viveros-Méndez, P X; Gil-Villegas, Alejandro; Aranda-Espinoza, S

2014-07-28

133

Thermal spray coatings replace hard chrome  

SciTech Connect

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

Schroeder, M.; Unger, R. [TAFA Inc., Concord, NH (United States)

1997-08-01

134

Deriving snow hardness from density and its application to the 1-D snow cover model SNOWPACK  

NASA Astrophysics Data System (ADS)

Estimating snow density (?s) based on snow hardness and grain type is often exploited in snow science. In snow hydrology snow water equivalent (SWE) that strongly depends on ?s needs to be determined; in avalanche forecasting an appropriate calculation of ?s is crucial to assess the load on a possible weak layer. However, collecting ?s is time consuming and difficult to do for very thin layers, and thus a parameterisation of ?son hand hardness is useful. On the other hand, the 1D snow cover model SNOWPACK derives snow hardness on simulated snow density. Recently, a new snow settling parameterization was introduced in the model which affects the simulation of density so that a new calibration is needed. We established a relation between ?sand hand hardness which is representative for various climatic regions of the European Alps. Two data sets including 14'455 dry-snow layers with measured density, grain type and hand hardness were used to relate density to hand hardness for the major grain types. The data were collected in the surroundings of Davos (Switzerland) and in the Veneto region (Italy), and cover different climatic regions and elevations. We applied least square and robust regressions to explore the data. The regression equations for both data sets were generally in reasonable agreement. The data collected in the Veneto region showed a higher variance than those of Davos; nevertheless the Veneto data was normally distributed and the mean values of ?s and hand hardness were highly correlated (R2? 0.9). Only for the grain type melt forms the correlation was lower. The linear relations were then used for the model calibration of SNOWPACK. First hardness simulations obtained with the different settings of the model are promising as simulated hardness is in fair agreement with observed values

Monti, F.; Schweizer, J.

2012-04-01

135

Revisit of interfacial free energy of the hard sphere system near hard wall  

E-print Network

We propose a simple Monte Carlo method to calculate the interfacial free energy between the substrate and the material. Using this method we investigate the interfacial free energys of the hard sphere fluid and solid phases near a smooth hard wall. According to the obtained interfacial free energys of the coexisting fluid and solid phases and the Young equation we are able to determine the contact angle with high accuracy, cos$\\theta$ = 1:010(31), which indicates that a smooth hard wall can be wetted completely by the hard sphere crystal at the interface between the wall and the hard sphere fluid.

Mingcheng Yang; Hongru Ma

2008-06-23

136

Hard diffraction results using D0  

SciTech Connect

The preliminary results on the search for hard diffraction in pp collisions with the D0 detector at Fermilab are presented. The presence of forward rapidity gaps is observed in events with high transverse momentum jet production at the center of mass energies 1800 and 630 GeV. The fraction of events with rapidity gaps is significantly higher than that expected due to multiplicity fluctuations and is consistent with predictions for hard single diffractive jet production. A class of events containing central dijets and two forward rapidity gaps is observed at {radical}s = 1800 GeV consistent with a hard double pomeron exchange event topology.

Shabalina, E. [Moskovskij Gosudarstvennyj Univ., Moscow (Russian Federation). Nauchno-Issledovatel`skij Inst. Yadernoj Fiziki; D0 Collaboration

1997-06-01

137

NNLO hard functions in massless QCD  

NASA Astrophysics Data System (ADS)

We derive the hard functions for all 2 ? 2 processes in massless QCD up to next-to-next-to-leading order (NNLO) in the strong coupling constant. By employing the known one- and two-loop helicity amplitudes for these processes, we obtain analytic expressions for the ultraviolet and infrared finite, minimally subtracted hard functions, which are matrices in color space. These hard functions will be useful in carrying out higher-order resummations in processes such as dijet and highly energetic top-quark pair production by means of soft-collinear effective theory methods.

Broggio, Alessandro; Ferroglia, Andrea; Pecjak, Ben D.; Zhang, Zhibai

2014-12-01

138

What's the Value in Value-Added?  

ERIC Educational Resources Information Center

A growing number of school districts are adopting "value-added" measures of teaching quality to award bonuses or even tenure. And two competitive federal grants are spurring them on. Districts using value-added data are encouraged by the results. But researchers who support value-added measures advise caution. The ratings, which use a statistical…

Duffrin, Elizabeth

2011-01-01

139

Exact second virial coefficient for dipolar hard spheres  

NASA Astrophysics Data System (ADS)

The second virial coefficient B2 for a fluid of dipolar hard spheres has been given several approximate forms valid in the limits of weak and strong interactions. They have been formulated as asymptotic expressions in a dimensionless interaction parameter ?. In this paper, B2 is determined exactly for all values of ? in both the three-dimensional case, where spheres may access the whole space and their dipole moments may be oriented in all directions, and in the quasi-two-dimensional case, where spheres have their centres bound to glide on a plane, while their dipole moments are still freely orientable in space.

Virga, Epifanio G.

2013-11-01

140

Anisotropic flow generated by hard partons in medium  

E-print Network

Hard partons which are produced copiously in nuclear collisions at the LHC, deposit most of their energy and momentum into the surrounding quark-gluon plasma. We show that this generates streams in the plasma and contributes importantly to flow anisotropies. With the help of event-by-event three-dimensional perfect hydrodynamic simulations we calculate the observable azimuthal anisotropies of hadronic distributions and show that the proposed mechanism is capable of generating non-negligible part of the observed signal. Hence, it must be taken into account in quantitative studies in which one tries to extract the values of viscosities from the comparison of simulated results with measured data.

Tomasik, Boris

2015-01-01

141

The Value of Reciprocity  

ERIC Educational Resources Information Center

The value of reciprocity in social exchange potentially comprises both instrumental value (the value of the actual benefits received from exchange) and communicative or symbolic value (the expressive and uncertainty reduction value conveyed by features of the act of reciprocity itself). While all forms of exchange provide instrumental value, we…

Molm, Linda D.; Schaefer, David R.; Collett, Jessica L.

2007-01-01

142

Values for Educational Leadership  

ERIC Educational Resources Information Center

What are values? Where do our values come from? How do our values make a difference in education? For educational leaders to achieve distinction in their practice, it is vital to establish clear personal values rather than reacting to the implicit values of others. This engaging book guides readers in considering the values they bring to their…

Haydon, Graham

2007-01-01

143

Effect of impurities on the hardness of alkali halide single crystals  

NASA Astrophysics Data System (ADS)

Micro hardness number of KCl, KBr and KCl-Br grown by Czocharlski technique, in the presence of homovalent and aliovalent ions of different ionic radii were measured in the indentation load range from 5 to 80*10-3 N. The measured data showed that there is an indentation size effect and classical Meyer's law was used for the characterization of crystal hardness of these crystals. The Meyer's index was also found to be smaller than 2 indicating brittle material characteristic. The P.R.S. model was used for the determination of the load independent micro hardness value. Result can be explained on the basis of interaction between created dislocation and point defect. It was found that hardness of these crystals is depending on the type of impurity.

Verma, Ashok K.; Ojha, Chaturbhuj; Shrivastava, A. K.

2014-04-01

144

Communication: Radial distribution functions in a two-dimensional binary colloidal hard sphere system  

NASA Astrophysics Data System (ADS)

Two-dimensional hard disks are a fundamentally important many-body model system in classical statistical mechanics. Despite their significance, a comprehensive experimental data set for two-dimensional single component and binary hard disks is lacking. Here, we present a direct comparison between the full set of radial distribution functions and the contact values of a two-dimensional binary colloidal hard sphere model system and those calculated using fundamental measure theory. We find excellent quantitative agreement between our experimental data and theoretical predictions for both single component and binary hard disk systems. Our results provide a unique and fully quantitative mapping between experiments and theory, which is crucial in establishing the fundamental link between structure and dynamics in simple liquids and glass forming systems.

Thorneywork, Alice L.; Roth, Roland; Aarts, Dirk G. A. L.; Dullens, Roel P. A.

2014-04-01

145

Trachypithecus cristatus (Primates: Cercopithecidae) LEE E. HARDING  

E-print Network

and Archipelago. It has a pointed crest and outward-projecting cheek hairs, and gray skin and pelage with some- graphed at Kuala Selangor Nature Park, Selangor, Malaysia, by L. Harding. MAMMALIAN SPECIES 42

Hayssen, Virginia

146

Warren G. Harding - Carrie Fulton Phillips Correspondence  

NSDL National Science Digital Library

As the 29th president of the United States, Warren G. Harding signed the first child welfare program into law, supported the 8-hour day in response to striking railroad workers, and prepared the first federal budget. Still, most historians regard HardingâÂÂs presidency as a flop. Who was this early 20th century politician? These letters, representing a fourteen-year correspondence between Harding and his married lover, Carrie Fulton Phillips, shed new light on this question. Start with the excellent Overview, which explains the court order that kept these documents from public view for over fifty years. Then take a look at the Collection Items, where the letters have been individually scanned. Lastly, Articles and Essays contains timelines for Harding, Phillips, and their relationship.

2014-01-01

147

Policy: Hard choices and soft outcomes?  

NASA Astrophysics Data System (ADS)

Asia's mega-deltas are densely populated and face multiple stressors including upstream development and sea-level rise. Adapting to these challenges requires difficult choices between hard and soft responses set within a strongly political context.

Conway, Declan

2015-02-01

148

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2012 CFR

...SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration...counted as “hard seed.” If at the end of the germination period provided...the percentage of germination. For flatpea, continue the swollen seed in test for 14...

2012-01-01

149

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2013 CFR

...SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration...counted as “hard seed.” If at the end of the germination period provided...the percentage of germination. For flatpea, continue the swollen seed in test for 14...

2013-01-01

150

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2011 CFR

...SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration...counted as “hard seed.” If at the end of the germination period provided...the percentage of germination. For flatpea, continue the swollen seed in test for 14...

2011-01-01

151

7 CFR 201.57 - Hard seeds.  

...SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration...counted as “hard seed.” If at the end of the germination period provided...the percentage of germination. For flatpea, continue the swollen seed in test for 14...

2014-01-01

152

Automated radiation hard ASIC design tool  

NASA Technical Reports Server (NTRS)

A commercial based, foundry independent, compiler design tool (ChipCrafter) with custom radiation hardened library cells is described. A unique analysis approach allows low hardness risk for Application Specific IC's (ASIC's). Accomplishments, radiation test results, and applications are described.

White, Mike; Bartholet, Bill; Baze, Mark

1993-01-01

153

The strength of hard-rock pillars  

Microsoft Academic Search

Observations of pillar failures in Canadian hard-rock mines indicate that the dominant mode of failure is progressive slabbing and spalling. Empirical formulas developed for the stability of hard-rock pillars suggest that the pillar strength is directly related to the pillar width-to-height ratio and that failure is seldom observed in pillars where the width-to-height ratio is greater than 2. Two-dimensional finite

C. d. Martin; W. g. Maybee

2000-01-01

154

EMP simulation for hardness verification testing  

NASA Astrophysics Data System (ADS)

A serious problem in the development of NEMP (nuclear electromagnetic pulse)-hardened systems is lack of adequate verification testing of the system hardness. The authors describe the development and use of a direct injection system designed specifically for threat-level hardness verification testing of complex systems with a number of electronic shelters interconnected by cables. Details of the theory and design of the synchronous injection system are presented. Experimental results related to the validity of the simulation technique are included.

Beilfuss, J.; Capobianco, J.; Gray, R.

155

Hard Versus Soft Law In International Security  

Microsoft Academic Search

The use and choice of hard and soft law in international gov-ernance has been the subject of ever-increasing scholarly interest. This law and social science literature has primarily assessed the relative strengths and weaknesses of hard- and soft-law instruments as alternatives for international governance, as well as how these instruments can be combined as mutually reinforcing complements to lead to

Gregory C Shaffer; Mark A Pollack

2011-01-01

156

Laser Ablatin of Dental Hard Tissue  

SciTech Connect

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

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

2007-07-31

157

Testing the Hardness of Common Minerals  

NSDL National Science Digital Library

This activity gives students practice and a chance to develop expertise in using the test for hardness in identifying common minerals. Following a discussion and an introduction to Moh's scale, the students will work in groups to test minerals whose identities are known against their standards (common substances whose hardnesses are known). Once the known minerals have been tested, the students can proceed to test unknown samples. A student worksheet and discussion questions are provided.

2005-10-06

158

Microstructural Characterization of Hard Ceramics Rohrer, G. S. (2014). Microstructural Characterization of Hard Ceramics. In V.K.  

E-print Network

Microstructural Characterization of Hard Ceramics Rohrer, G. S. (2014). Microstructural Characterization of Hard Ceramics. In V.K. Sarin (Editor-in-Chief) & L #12;Microstructural Characterization of Hard Ceramics p. 2 4. Summary

Rohrer, Gregory S.

159

Hard x ray highlights of AR 5395  

NASA Technical Reports Server (NTRS)

Active Region 5395 produced an exceptional series of hard x ray bursts notable for their frequency, intensity, and impulsivity. Over the two weeks from March 6 to 19, 447 hard x ray flares were observed by the Hard X Ray Burst Spectrometer on Solar Maximum Mission (HXRBS/SMM), a rate of approx. 35 per day which exceeded the previous high by more than 50 percent. During one 5 day stretch, more than 250 flares were detected, also a new high. The three largest GOES X-flares were observed by HXRBS and had hard x ray rates over 100,000 s(exp -1) compared with only ten flares above 100,000(exp -1) during the previous nine years of the mission. An ongoing effort for the HXRBS group has been the correlated analysis of hard x ray data with flare data at other wavelengths with the most recent emphasis on those measurements with spatial information. During a series of bursts from AR 5395 at 1644 to 1648 UT on 12 March 1989, simultaneous observations were made by HXRBS and UVSP (Ultra Violet Spectrometer Polarimeter) on SMM, the two-element Owens Valley Radio Observatory (OVRO) interferometric array, and R. Canfield's H-alpha Echelle spectrograph at the National Solar Observatory at Sacramento Peak. The data show strong correlations in the hard x ray, microwave, and UV lightcurves. This event will be the subject of a combined analysis.

Schwartz, R. A.; Dennis, Brian R.

1989-01-01

160

RAD hard PROM design study  

NASA Technical Reports Server (NTRS)

The results of a preliminary study on the design of a radiation hardened fusible link programmable read-only memory (PROM) are presented. Various fuse technologies and the effects of radiation on MOS integrated circuits are surveyed. A set of design rules allowing the fabrication of a radiation hardened PROM using a Si-gate CMOS process is defined. A preliminary cell layout was completed and the programming concept defined. A block diagram is used to describe the circuit components required for a 4 K design. A design goal data sheet giving target values for the AC, DC, and radiation parameters of the circuit is presented.

1981-01-01

161

Abrasivity Assessment of Granitic Building Stones in Relation to Diamond Tool Wear Rate Using Mineralogy-Based Rock Hardness Indexes  

NASA Astrophysics Data System (ADS)

The objective of the present study was to determine the abrasive wear potential of granites in circular sawing using some mineralogy-based rock hardness indexes. A literature study indicated that little or no attention has been given to assessing this kind of relationship in the field of stone processing. To accomplish this objective, sawing experiments were performed on nine different granites used widely as building and decorative stone materials. The measured sawblade-specific wear rates were correlated with three different rock hardness indexes attained by combining the percentage content of hard mineral constituents with their known hardness values. Statistical analysis of the experimental data revealed that rock hardness indexes that are based on both Vickers hardness number and Rosiwal hardness could be accepted as reliable indicators of granite abrasivity. These two indexes were also found to correlate well with the average power drawn during the process. However, the rock abrasivity index based on Mohs relative scratch hardness did not show statistically significant correlations with sawblade wear rate and power drawn. Although quartz percentage content is regarded as an important abrasivity parameter by practitioners, the observations made here indicate that consideration of quartz percentage content alone is not sufficient to describe the abrasive potential of granites, and thus incorporation of other hard mineral constituents could be more suitable.

Y?lmaz, Nurdan Güne?

2011-11-01

162

Maslow and Values Education  

ERIC Educational Resources Information Center

Identifies major value bases which have been used to teach values in the classroom and outlines a values education program which stresses teaching about values without indoctrination. Based upon the hierarchy of human needs developed by psychologist Abraham Maslow, the program is based upon universal values, basic human needs, and recognition of…

Farmer, Rodney

1978-01-01

163

VALUE CREATION ANALYSIS. ECONOMIC VALUE ADDED  

Microsoft Academic Search

The origins of the Economic Value Added comes from Hamilton (1877) and Marshall (1890), which showed that companies can create wealth if you manage to earn more than their own capital costs and liabilities. Economic Value Added is an indicator for measuring performance based on real economic profits of the company product, which allows measurement of its success or failure

Silvia Petrescu; Ciprian Apostol

2009-01-01

164

Scaled particle theory for hard sphere pairs. I. Mathematical structure.  

PubMed

We develop an extension of the original Reiss-Frisch-Lebowitz scaled particle theory that can serve as a predictive method for the hard sphere pair correlation function g(r). The reversible cavity creation work is analyzed both for a single spherical cavity of arbitrary size, as well as for a pair of identical such spherical cavities with variable center-to-center separation. These quantities lead directly to a prediction of g(r). Smooth connection conditions have been identified between the small-cavity situation where the work can be exactly and completely expressed in terms of g(r), and the large-cavity regime where macroscopic properties become relevant. Closure conditions emerge which produce a nonlinear integral equation that must be satisfied by the pair correlation function. This integral equation has a structure which straightforwardly generates a solution that is a power series in density. The results of this series replicate the exact second and third virial coefficients for the hard sphere system via the contact value of the pair correlation function. The predicted fourth virial coefficient is approximately 0.6% lower than the known exact value. Detailed numerical analysis of the nonlinear integral equation has been deferred to the subsequent paper. PMID:17144712

Stillinger, Frank H; Debenedetti, Pablo G; Chatterjee, Swaroop

2006-11-28

165

Glass transition of hard spheres in high dimensions  

NASA Astrophysics Data System (ADS)

We have investigated analytically and numerically the liquid-glass transition of hard spheres for dimensions d?? in the framework of mode-coupling theory. The numerical results for the critical collective and self-nonergodicity parameters fc(k;d) and fc(s)(k;d) exhibit non-Gaussian k dependence even up to d=800 . fc(s)(k;d) and fc(k;d) differ for k˜d1/2 , but become identical on a scale k˜d , which is proven analytically. The critical packing fraction ?c(d)˜d22-d is above the corresponding Kauzmann packing fraction ?K(d) derived by a small cage expansion. Its quadratic pre-exponential factor is different from the linear one found earlier. The numerical values for the exponent parameter and therefore the critical exponents a and b depend on d , even for the largest values of d .

Schmid, Bernhard; Schilling, Rolf

2010-04-01

166

Consciousness in Robots: The Hard Problem and Some Less Hard Problems  

E-print Network

Consciousness in Robots: The Hard Problem and Some Less Hard Problems B. J. MacLennan Department by consciousness in autonomous robots. We dis- tinguish intrinsic intentionality from consciousness, but argue- jective awareness) from the perspective of the theory of protophenomena. Index Terms ­ consciousness

Wang, Xiaorui "Ray"

167

ESTIMATING THE DENSITY OF DRY SNOW LAYERS FROM HARDNESS, AND HARDNESS FROM DENSITY  

E-print Network

ESTIMATING THE DENSITY OF DRY SNOW LAYERS FROM HARDNESS, AND HARDNESS FROM DENSITY Daehyun Kim 1 ABSTRACT: At the ISSW 2000, Geldsetzer and Jamieson presented empirical relations between the density density and water equivalent (e.g. because the layer was too thin for the density sampler

Jamieson, Bruce

168

Instrumentation and data analysis for hard X ray astronomy  

Microsoft Academic Search

The current status of hard x ray astronomy is reviewed. The applicability of various hard x ray detectors in such new telescopes are discussed and the current status of hard x ray telescope design is reviewed. Background production mechanisms in hard x ray telescopes are discussed and some techniques for background reduction are also discussed. A simple method for estimating

Shuang Nan Zhang

1989-01-01

169

Application of Rapid Visco Analyser (RVA) viscograms and chemometrics for maize hardness characterisation.  

PubMed

It has been established in this study that the Rapid Visco Analyser (RVA) can describe maize hardness, irrespective of the RVA profile, when used in association with appropriate multivariate data analysis techniques. Therefore, the RVA can complement or replace current and/or conventional methods as a hardness descriptor. Hardness modelling based on RVA viscograms was carried out using seven conventional hardness methods (hectoliter mass (HLM), hundred kernel mass (HKM), particle size index (PSI), percentage vitreous endosperm (%VE), protein content, percentage chop (%chop) and near infrared (NIR) spectroscopy) as references and three different RVA profiles (hard, soft and standard) as predictors. An approach using locally weighted partial least squares (LW-PLS) was followed to build the regression models. The resulted prediction errors (root mean square error of cross-validation (RMSECV) and root mean square error of prediction (RMSEP)) for the quantification of hardness values were always lower or in the same order of the laboratory error of the reference method. PMID:25466147

Guelpa, Anina; Bevilacqua, Marta; Marini, Federico; O'Kennedy, Kim; Geladi, Paul; Manley, Marena

2015-04-15

170

Structural and relative stabilities, electronic properties, and hardness of iron tetraborides from first prinicples.  

PubMed

First-principles calculations were carried out to investigate the structure, phase stability, electronic property, and roles of metallicity in the hardness for recently synthesized FeB4 with various different structures. Our calculation indicates that the orthorhombic phase with Pnnm symmetry is the most energetically stable one. The other four new dynamically stable phases belong to space groups monoclinic C2/m, orthorhombic Pmmn, trigonal R3?m, and hexagonal P63/mmc. Their mechanical and thermodynamic stabilities are verified by calculating elastic constants, formation enthalpies, and phonon dispersions. We found that all phases are stabilized further under pressure. Above the pressure of about 50 GPa, the formation enthalpy of Pmmn is almost equal to that of P63/mmc phase. The analysis on density of states not only demonstrates that formation of strong covalent bonding in these compounds contributes greatly to their stabilities but also that they all exhibit metallic behavior which does not relate to the approach used. By considering metallic contributions, the estimated Vickers hardness values based on the semiempirical model show that the OsB4-structured FeB4, with a hardness of 48.1 GPa, well exceeding the limitation of superhardness (40 GPa), is more hard than the most stable phase. The others are predicted to be potential hard materials. Moreover, the atomic configuration and strong B-B covalent bonds are found to play important roles in the hardness of materials. PMID:24605919

Ding, Li-Ping; Kuang, Xiao-Yu; Shao, Peng; Huang, Xiao-Fen

2014-04-01

171

Soft Power and Hard Measures: Large-Scale Assessment, Citizenship and the European Union  

ERIC Educational Resources Information Center

This article explores the International Civic and Citizenship Education Study (ICCS) with particular emphasis on the European Union's (EU's) involvement in the regional portion. Using the ICCS, the EU actively combines hard measures with soft power, allowing the EU to define and steer cross-national rankings of values of EU citizenship. The…

Rutkowski, David; Engel, Laura C.

2010-01-01

172

EVALUATION OF STRUCTURAL MODIFICATION OF A HARD DEEP CLAYEY ROCK DUE TO WETTING / DRYING CYCLES  

E-print Network

a higher value -as usual-, about 10"19 m2 . Different types of microscopes were used to characterizeEVALUATION OF STRUCTURAL MODIFICATION OF A HARD DEEP CLAYEY ROCK DUE TO WETTING / DRYING CYCLES and water content were measured in order to estimate the importance of physical changes. Then mercury

Paris-Sud XI, Université de

173

Adaptive regulation of the flying height for a 2DOF tripad slider in hard disk drives  

Microsoft Academic Search

Maintaining a small flying height of the read\\/write head above the disk surface is essential to the development of ultra high storage density hard disk drives. This paper proposes an adaptive regulation approach to maintain the flying height at its desired value, despite the unknown vibrations and the unknown microwaviness in the disk surface profile. Firstly, a parameterized set of

Zhizheng Wu; Foued Ben Amara

2005-01-01

174

Hard template synthesis of metal nanowires.  

PubMed

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. PMID:25453031

Kawamura, Go; Muto, Hiroyuki; Matsuda, Atsunori

2014-01-01

175

Erosion testing of hard materials and coatings  

SciTech Connect

Erosion is the process by which unconstrained particles, usually hard, impact a surface, creating damage that leads to material removal and component failure. These particles are usually very small and entrained in fluid of some type, typically air. The damage that occurs as a result of erosion depends on the size of the particles, their physical characteristics, the velocity of the particle/fluid stream, and their angle of impact on the surface of interest. This talk will discuss the basics of jet erosion testing of hard materials, composites and coatings. The standard test methods will be discussed as well as alternative approaches to determining the erosion rate of materials. The damage that occurs will be characterized in genera1 terms, and examples will be presented for the erosion behavior of hard materials and coatings (both thick and thin).

Hawk, Jeffrey A.

2005-04-29

176

Potential Health Impacts of Hard Water  

PubMed Central

In the past five decades or so evidence has been accumulating about an environmental factor, which appears to be influencing mortality, in particular, cardiovascular mortality, and this is the hardness of the drinking water. In addition, several epidemiological investigations have demonstrated the relation between risk for cardiovascular disease, growth retardation, reproductive failure, and other health problems and hardness of drinking water or its content of magnesium and calcium. In addition, the acidity of the water influences the reabsorption of calcium and magnesium in the renal tubule. Not only, calcium and magnesium, but other constituents also affect different health aspects. Thus, the present review attempts to explore the health effects of hard water and its constituents. PMID:24049611

Sengupta, Pallav

2013-01-01

177

A Method for Measuring the Hardness of the Surface Layer on Hot Forging Dies Using a Nanoindenter  

NASA Astrophysics Data System (ADS)

The properties and characteristics of the surface layer of forging dies are critical for understanding and controlling wear. However, the surface layer is very thin, and appropriate property measurements are difficult to obtain. The objective of the present study is to determine if nanoindenter testing provides a reliable method, which could be used to measure the surface hardness in forging die steels. To test the reliability of nanoindenter testing, nanoindenter values for two quenched and tempered steels (FX and H13) are compared to microhardness and macrohardness values. These steels were heat treated for various times to produce specimens with different values of hardness. The heat-treated specimens were tested using three different instruments—a Rockwell hardness tester for macrohardness, a Vickers hardness tester for microhardness, and a nanoindenter tester for fine scale evaluation of hardness. The results of this study indicate that nanoindenter values obtained using a Nanoindenter XP Machine with a Berkovich indenter reliably correlate with Rockwell C macrohardness values, and with Vickers HV microhardness values. Consequently, nanoindenter testing can provide reliable results for analyzing the surface layer of hot forging dies.

Mencin, P.; van Tyne, C. J.; Levy, B. S.

2009-11-01

178

Epidemiological study of hard metal asthma.  

PubMed Central

OBJECTIVES: To elucidate factors contributing to hard metal asthma, the entire workforce of a corporation producing hard metal tools (n = 703) was examined. METHODS: The variables evaluated were the atopy reflected by immunoglobulin E (IgE) antibody against mite allergen, history of exposure to hard metal, smoking, concentration of airborne cobalt, specific IgE antibody reaction against cobalt, and the respiratory symptom of attacks of reversible dyspnoea with wheeze (asthmatic symptoms). RESULTS: Univariate analysis showed that the prevalence of the asthmatic symptoms was significantly higher in formerly and currently exposed male workers than in non-exposed male workers. Positive IgE reaction against cobalt was found in seven men (2.0%), all of whom had asthmatic symptoms. Furthermore, it was found that atopy, positive IgE antibody against cobalt, and age of 40 or older were significantly correlated with asthmatic symptoms. Multilogistic analysis on the same factors and smoking in all of the workers showed that the age, experience of hard metal exposure, and atopy were significant risk factors associated with the asthmatic symptoms. Multilogistic analysis of data for currently exposed and non-exposed workers also showed that age and atopy were risk factors, and that the exposure to cobalt at the low concentration (at or below 50 micrograms/m3) but not at the higher concentration was a significant risk factor. Exposure to mist of coolants containing ionic cobalt, used during grinding, was not found to be any more hazardous in terms of onset of asthmatic symptoms than exposure to hard metal dust containing metallic cobalt. CONCLUSIONS: Accordingly, it is concluded that both environmental factors and individual susceptibility should be taken into consideration in efforts to reduce the prevalence of hard metal asthma. PMID:8704860

Kusaka, Y; Iki, M; Kumagai, S; Goto, S

1996-01-01

179

Financial and environmental modelling of water hardness--implications for utilising harvested rainwater in washing machines.  

PubMed

A study was conducted to determine the financial and environmental effects of water quality on rainwater harvesting systems. The potential for replacing tap water used in washing machines with rainwater was studied, and then analysis presented in this paper is valid for applications that include washing machines where tap water hardness may be important. A wide range of weather conditions, such as rainfall (284-1,794 mm/year); water hardness (14-315 mg/L CaCO3); tap water prices (0.85-2.65 Euros/m(3)) in different Spanish urban areas (from individual buildings to whole neighbourhoods); and other scenarios (including materials and water storage capacity) were analysed. Rainfall was essential for rainwater harvesting, but the tap water prices and the water hardness were the main factors for consideration in the financial and the environmental analyses, respectively. The local tap water hardness and prices can cause greater financial and environmental impacts than the type of material used for the water storage tank or the volume of the tank. The use of rainwater as a substitute for hard water in washing machines favours financial analysis. Although tap water hardness significantly affects the financial analysis, the greatest effect was found in the environmental analysis. When hard tap water needed to be replaced, it was found that a water price of 1 Euro/m(3) could render the use of rainwater financially feasible when using large-scale rainwater harvesting systems. When the water hardness was greater than 300 mg/L CaCO3, a financial analysis revealed that an net present value greater than 270 Euros/dwelling could be obtained at the neighbourhood scale, and there could be a reduction in the Global Warming Potential (100 years) ranging between 35 and 101 kg CO2 eq./dwelling/year. PMID:24262990

Morales-Pinzón, Tito; Lurueña, Rodrigo; Gabarrell, Xavier; Gasol, Carles M; Rieradevall, Joan

2014-02-01

180

Heat treatment effect on microstructure, hardness and wear resistance of Cr26 white cast iron  

NASA Astrophysics Data System (ADS)

High chromium cast iron(HCCI) is taken as material of coal water slurry pump impeller, but it is susceptible to produce serious abrasive wear and erosion wear because of souring of hard coal particles. The research on optimization of heat treatments to improve abrasive wear properties of HCCI is insufficient, so effect of heat treatments on the microstructure, hardness, toughness, and wear resistance of Cr26 HCCI is investigated to determine the optimal heat treatment process for HCCI. A series of heat treatments are employed. The microstructures of HCCI specimens are examined by using optical microscopy and scanning electron microscopy. The hardness and impact fracture toughness of as-cast and heat treated specimens are measured. The wear tests are assessed by a Type M200 ring-on block wear tester. The results show the following: With increase of the quenching temperature from 950 °C to 1050 °C, the hardness of Cr26 HCCI increased to a certain value, kept for a time and then decreased. The optimal heat treatment process is 2 h quenching treatment at 1000 °C, followed by a subsequent 2 h tempering at 400 °C. The hardness of HCCI is related to the precipitation and redissolution of secondary carbides in the process of heat treatment. The subsequent tempering treatment would result in a slight decrease of hardness but increase of toughness. The wear resistance is much related to the "supporting" effect of the matrix and the "protective" effect of the hard carbide embedded in the matrix, and the wear resistance is further dependent on the hardness and the toughness of the matrix. This research can provide an important insight on developing an optimized heat treatment method to improve the wear resistance of HCCI.

Zhou, Shaoping; Shen, Yehui; Zhang, Hao; Chen, Dequan

2014-08-01

181

Physiological, perceptual, and technical responses to on-court tennis training on hard and clay courts.  

PubMed

The aim of this study was to investigate the effect of court surface (clay vs. hard court) on technical, physiological, and perceptual responses to on-court tennis training. Four high-performance junior male players performed 2 identical training sessions on hard and clay courts, respectively. Sessions included both physical conditioning and technical elements as led by the coach. Each session was filmed for later notational analysis of stroke count and error rates. Furthermore, players wore a global positioning satellite device to measure distance covered during each session, while heart rate, countermovement jump distance, and capillary blood measures of metabolites were measured before, during, and after each session. Additionally, a respective coach and athlete rating of perceived exertion (RPE) were measured after each session. Total duration and distance covered during each session were comparable (p > 0.05; d < 0.20). Although forehand and backhands stroke volume did not differ between sessions (p > 0.05; d < 0.30), large effects for increased unforced and forced errors were present on the hard court (p > 0.05; d > 0.90). Furthermore, large effects for increased heart rate, blood lactate, and RPE values were evident on clay compared with hard courts (p > 0.05; d > 0.90). Additionally, although player and coach RPE on hard courts were similar, there were large effects for coaches to underrate the RPE of players on clay courts (p > 0.05; d > 0.90). In conclusion, training on clay courts results in trends for increased heart rate, lactate, and RPE values, suggesting that sessions on clay courts tend towards higher physiological and perceptual loads than hard courts. Furthermore, coaches seem effective at rating player RPE on hard courts but may underrate the perceived exertion of sessions on clay courts. PMID:22890497

Reid, Machar M; Duffield, Rob; Minett, Geoffrey M; Sibte, Narelle; Murphy, Alistair P; Baker, John

2013-06-01

182

Five Values of Giftedness  

ERIC Educational Resources Information Center

This article describes five values attributed to giftedness. The ascription of values to this phenomenon resembles values attached to gifts in gift-giving processes. Whereas gift-giving often includes expectations of reciprocity, each gift possesses a numerical, utility, social, personal, and intrinsic value. Developmental models of giftedness and…

Besjes-de Bock, Karin M.; de Ruyter, Doret J.

2011-01-01

183

Values and Youth.  

ERIC Educational Resources Information Center

Every social studies teacher must consciously move to relate his course to the value dilemmas of youth and the value-laden issues of our time. A variety of writings by youth have been included to serve as source materials for classroom teachers and to provide significant insights into the values of youth. The section, Values in the Classroom:…

Barr, Robert D., Ed.

184

Teaching Absolute Value Meaningfully  

ERIC Educational Resources Information Center

What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

Wade, Angela

2012-01-01

185

Hard-thermal-loop QED thermodynamics  

E-print Network

The weak-coupling expansion for thermodynamic quantities in thermal field theories is poorly convergent unless the coupling constant is tiny. We discuss the calculation of the free energy for a hot gas of electrons and photons to three-loop order using hard-thermal-loop perturbation theory (HTLpt). We show that the hard-thermal-loop perturbation reorganization improves the convergence of the successive approximations to the QED free energy at large coupling, e ~ 2. The reorganization is gauge invariant by construction, and due to the cancellations among various contributions, we obtain a completely analytic result for the resummed thermodynamic potential at three loops.

Nan Su; Jens O. Andersen; Michael Strickland

2009-11-24

186

Hard Discs on the Hyperbolic Plane  

E-print Network

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

Carl D. Modes; Randall D. Kamien

2007-11-30

187

Hard disks on the hyperbolic plane.  

PubMed

We examine a simple hard disk fluid with no long range interactions on the two-dimensional space of constant negative Gaussian curvature, the hyperbolic plane. This geometry provides a natural mechanism by which global crystalline order is frustrated, allowing us to construct a tractable model of disordered monodisperse hard disks. We extend free-area theory and the virial expansion to this regime, deriving the equation of state for the system, and compare its predictions with simulation near an isostatic packing in the curved space. PMID:18233384

Modes, Carl D; Kamien, Randall D

2007-12-01

188

Novel Aspects of Hard Diffraction in QCD  

E-print Network

Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, and nuclear shadowing and antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency.

S. J. Brodsky

2005-09-21

189

Registration of Anton Hard White Winter Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

190

Clinical findings among hard metal workers.  

PubMed Central

In 1940, the first report appeared describing a pulmonary disorder associated with occupational exposures in the cemented tungsten carbide industry. The disease, known as "hard metal disease," has subsequently been characterised in detail and comprises a wide range of clinical signs and symptoms. In this report, clinical findings in a group of 41 hard metal workers employed until recently are described. A high prevalence of respiratory symptoms was found. Thirteen workers (31%) had abnormal chest radiographs indicative of interstitial lung disease. Fifty per cent of these had been employed in hard metal manufacturing for less than 10 years. Abnormalities of pulmonary function were also frequent and included a restrictive pattern of impairment and decrease in diffusing capacity (27%). Associations were found between diffusing capacity, chest radiographic abnormalities and right ventricular ejection fraction at exercise indicating cardiopulmonary effects. The findings show the continuous need to control excessive occupational exposures to prevent hard metal disease, the history of which now enters its sixth decade. PMID:1733452

Fischbein, A; Luo, J C; Solomon, S J; Horowitz, S; Hailoo, W; Miller, A

1992-01-01

191

HEPGEN - generator for hard exclusive leptoproduction  

E-print Network

HEPGEN is a generator of Monte Carlo events, which is dedicated to studies of hard exclusive single photon or meson production processes at the COMPASS experiment kinematic domain. In addition HEPGEN allows to generate also single photon or meson production accompanied by the diffractive dissociation of the nucleon, which is one of the main sources of background in analyses of exclusive processes.

A. Sandacz; P. Sznajder

2012-07-02

192

DIELECTRIC SPECTROSCOPY OF HARD RED WINTER WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The dielectric properties (components of the complex permittivity relative to free space) of ground hard red winter wheat of 11 to 25 percent moisture content were determined by dielectric spectroscopy measurements with an open-ended coaxial-line probe and impedance analyzer over the frequency range...

193

Sustaining Transformation: "Resiliency in Hard Times"  

ERIC Educational Resources Information Center

The strategic, systemic, and encompassing evolution of a college or university spans a number of years, and the vagaries of economic cycles inevitably catch transforming institutions in mid-voyage. "Sustaining Transformation: Resiliency in Hard Times" presents a study of Wagner College as it moves into its second decade of purposeful institutional…

Guarasci, Richard; Lieberman, Devorah

2009-01-01

194

Varietal Trials Results Wheat, Hard Red Winter  

E-print Network

Varietal Trials Results Wheat, Hard Red Winter 47 Winter wheat varieties were compared in trial plots at Crookston, Lamberton, Roseau and St. Paul. Wheat varieties were grown in replicated plots. These winter wheat trials are not designed for crop (species) compar- isons because the various crops are grown

Thomas, David D.

195

Hard-to-reach populations in Japan.  

PubMed

The objective of this study was to assess the trends of sampling locations and methods of studying hard-to-reach populations conducted in Japan. We accessed a Japanese medical database on 30 September 2005 to review 5 study types of hard-to-reach populations conducted in Japan: men who have sex with men, homeless, sex workers, undocumented migrants, and injecting drug users. We then categorized their sampling locations and methods. We found 298 articles on hard-to-reach populations published from 1983 to September 2005. Of the 285 studies sampled, approximately 92% were facility-based studies and the rest were community-based. This tendency was consistent in each subgroup; the majority of the studies were conducted among patients in medical facilities. Our study shows the majority of studies on hard-to-reach populations in Japan adopted a convenience sampling method and were facility-based. We suggest the utilization of comparatively valid techniques, such as time-location or respondent driven sampling to more clearly understand these populations. PMID:17539282

Nomura, Yuka; Poudel, Krishna C; Jimba, Masamine

2007-03-01

196

PROTEIN TEMPLATES IN HARD TISSUE ENGINEERING  

PubMed Central

Biomineralization processes such as formation of bones and teeth require controlled mineral deposition and self-assembly into hierarchical biocomposites with unique mechanical properties. Ideal biomaterials for regeneration and repair of hard tissues must be biocompatible, possess micro and macroporosity for vascular invasion, provide surface chemistry and texture that facilitate cell attachment, proliferation, differentiation of lineage specific progenitor cells, and induce deposition of calcium phosphate mineral. To expect in-vivo like cellular response several investigators have used extracellular matrix proteins as templates to recreate in-vivo microenvironment for regeneration of hard tissues. Recently, several novel methods of designing tissue repair and restoration materials using bioinspired strategies are currently being formulated. Nanoscale structured materials can be fabricated via the spontaneous organization of self-assembling proteins to construct hierarchically organized nanomaterials. The advantage of such a method is that polypeptides can be specifically designed as building blocks incorporated with molecular recognition features and spatially distributed bioactive ligands that would provide a physiological environment for cells in-vitro and in-vivo. This is a rapidly evolving area and provides a promising platform for future development of nanostructured templates for hard tissue engineering. In this review we try to highlight the importance of proteins as templates for regeneration and repair of hard tissues as well as the potential of peptide based nanomaterials for regenerative therapies. PMID:20802848

George, Anne; Ravindran, Sriram

2010-01-01

197

Hard rock mining on the public land  

Microsoft Academic Search

This report analyzes the current government policy for developing hard rock mineral wealth and seeks to identify the crucial objectives which should guide such a policy - whatever it may be. Deficiencies in the current policy are revealed. The emphasis here is on exposition rather than prescription, although alternative courses of action are cited. Because of the rich and varied

1977-01-01

198

Ground mechanics in hard rock mining  

Microsoft Academic Search

Ground mechanics in hard rock mining represents a combination of applied science and mining engineering experience in ground control and excavation. The problems discussed reflect the present state of underground mining technology. Topics covered include the following: concepts of stress and strain; deformations of rocks; failure of rocks; strength of rocks; monitoring of rock structure; ground conditions; ground stresses; mine

Jeremic

1986-01-01

199

Soft Skills, Hard Program for STEM  

E-print Network

Soft Skills, Hard Science: A Program for STEM Students with Disabilities Laura McCullough, Kathleen Deery, Michael Lawler, Debra Homa University of Wisconsin-Stout NSF Grant #RDE-1129682 May 2014 Women job placement rates for STEM students with Disabilities Monday, June 9, 14 #12;Employment gap STEM

Wu, Mingshen

200

Maximum Likelihood of Evolutionary Trees is Hard  

E-print Network

Basic Science Questions (1) Creation and evolution of the universe. Benny Chor and Tamir Tuller: ML on evolutionary trees is hard ­ p.2 #12;Challenging Basic Science Questions (1) Creation and evolution Questions (1) Creation and evolution of the universe. Fascinating, but not topic of talk. Benny Chor

Beimel, Amos

201

COMPUTATIONAL HARDNESS OF VALIDITY IN PROBABILITY LOGIC  

E-print Network

COMPUTATIONAL HARDNESS OF VALIDITY IN PROBABILITY LOGIC RUTGER KUYPER Abstract. We consider the complexity of validity in -logic, a probability logic introduced by Terwijn. We prove that the set of valid, there have been many attempts at combining logic and probability through so-called probability logics. We

Bosma, Wieb

202

Microfabricated electrostatic actuators for hard disk drives  

Microsoft Academic Search

A dual-stage servo system which utilizes a high-bandwidth secondary actuator has been proposed for magnetic hard disk drives. Microfabricated actuators are promising candidates for this secondary actuator, since they offer the benefits of extremely small size and weight and may be batch fabricated for reduced production cost. This paper presents the design of an electrostatic microactuator which produces sufficient output

David A. Horsley; Roberto Horowitz; Albert P. Pisano

1998-01-01

203

Future trends in hard disk drives  

Microsoft Academic Search

Magnetic hard disk drives have significantly improved in size, performance and cost due to many technological innovations; including magnetoresistive heads, low noise thin film disks, PRML channels and advanced mechanical actuators and motors. By analyzing specification trends of each new disk drive design, a perspective of this evolution can be developed and design characteristics of future disk drives can be

Edward Grochowski; Roger F. Hoyt

1996-01-01

204

Spherical reference systems for nonspherical hard interactions  

Microsoft Academic Search

Results are presented on three complex systems of hard molecules: linear triatomics, heteronuclear dumbbells, and two-component mixtures of dumbbells. In addition to studying the equation of state generated by the median potential, the Barker-Henderson reference system is also investigated and seen to give results nearly indistinguishable from those obtained from the median system. Both reference systems continue to reproduce the

G. O. Williams; J. L. Lebowitz; J. K. Percus

1984-01-01

205

Surgical lasers and hard dental tissue  

Microsoft Academic Search

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

S. Parker

2007-01-01

206

Climate dynamics of a hard snowball Earth  

Microsoft Academic Search

The problem of deglaciating a globally ice-covered (“hard snowball”) Earth is examined using a series of general circulation model simulations. The aim is to determine the amount of CO2 that must be accumulated in the atmosphere in order to trigger deglaciation. Prior treatments of this problem have been limited to energy balance models, which are incapable of treating certain crucial

R. T. Pierrehumbert

2005-01-01

207

Arsenic, nitrate, iron, and hardness in ground water, Chena Ridge vicinity, Fairbanks, Alaska  

USGS Publications Warehouse

The report presents all data on hardness, iron, nitrate and arsenic in well water in the Chena Ridge area of Fairbanks, Alaska, through June 1979. Concentrations range as follows: arsenic - 0 to 28 micrograms per liter; nitrate - 0 to 20 milligrams per liter; iron - 0 to 18 milligrams per liter and hardness - 72 to 1,400 milligrams per liter. Values at the upper ends of the ranges for iron and nitrate exceed limits recommended by the Environmental Protection Agency for public water supplies. A map of the area showing the location of sampled wells and a table of chemical analysis are included. (Kosco-USGS)

Krumhardt, Andrea P.

1979-01-01

208

She works hard for the money: Valuing effort underlies gender differences in behavioral self-handicapping  

Microsoft Academic Search

Research in the area of self-handicapping has consistently demonstrated a robust yet puzzling gender difference in the use of and evaluation of behavioral self-handicaps; women (1) are less likely to use these forms of handicaps, particularly those involving the actual or reported reduction of effort, and (2) evaluate the use of these handicaps by others more negatively than do men.

Sean M. McCrea; Edward R. Hirt; Bridgett J. Milner

2008-01-01

209

Education, Values, and Valuing in Cosmopolitan Perspective  

ERIC Educational Resources Information Center

In this article we describe a cosmopolitan orientation toward the place of values in human life. We argue that a cosmopolitan outlook can assist people in engaging the challenges of being thrown together with others whose roots, traditions, and inheritances differ. We show that cosmopolitanism implies neither an elite nor an aloof posture toward…

Hansen, David T.; Burdick-Shepherd, Stephanie; Cammarano, Cristina; Obelleiro, Gonzalo

2009-01-01

210

What's the Value in Value-Added?  

ERIC Educational Resources Information Center

As the profession of teaching continues to get more attention given recent events, a growing number of school districts from New York to California are adopting "value-added" measures of teaching quality to award bonuses or even tenure. And two competitive federal grants are spurring them on. The Teacher Incentive Fund has awarded 95 grants since…

Duffrin, Elizabeth

2011-01-01

211

Outcome Values and Aggression.  

ERIC Educational Resources Information Center

This study tested the hypothesis that aggressive children attach more value to rewarding outcomes of aggression and less to negative outcomes than do nonaggressive children. Sex differences in outcome values were also examined. (PCB)

Boldizar, Janet P.; And Others

1989-01-01

212

Identifying Extreme Exposure Values  

Cancer.gov

There are various perspectives on whether to exclude potentially unlikely exposure values. If the researcher chooses to do so, several approaches exist for identifying extreme values. We examined the plausibility of the reported frequencies for each food item in the NHANES 2009-10 DSQ and chose to exclude extreme values using a method that identifies them based on the actual distribution of the sample, but also minimizes the number of values excluded.

213

Place Value Rocks!  

NSDL National Science Digital Library

Play these educational math games and test your knowledge of Place Value! Can you use Place Value Blocks to help you represent different digits? Test your ability to write out given numbers into sentences with Cookies! How sharp are your place value skills? Test your knowledge with Golfing with numbers!! Be the hero of the day as you practice place value skills in the Lifeguard game! Reveal the ...

Ms.roberts

2009-03-04

214

Values and Creativity  

Microsoft Academic Search

Does extrinsic motivation inhibit or foster creativity? Whereas previous researchers examined the effects of externally controlled extrinsic motivation on creativity, we focus on the effects of self-determined extrinsic motivation arising from one's personally held core values. In this study, we present a theoretical argument which predicts that (a) creative behavior is fostered by certain value types, inhibited by other value

Joseph Kasof; Chuansheng Chen; Amy Himsel; Ellen Greenberger

2007-01-01

215

From Values to \\  

Microsoft Academic Search

Mella, par. 1-4) Strictly speaking, firms are considered as systems for the creation of economic and financial value for their shareholders, and their performance - profit and the value of capital - is measured by a coherent system of monetary values. Nevertheless, if we do not limit our view to simply the shareholders but consider instead a vast group of

Patrizia Gazzola; Piero Mella

216

Summer Place Value  

NSDL National Science Digital Library

Play some fun games with your new place value skills Match the number words to the standard form to find the place value mystery picture. Can you solve the place value puzzler? Click on easy and follow the instructions. Check your score after the picture is shown. How many tries did it take you to be able to see the picture. If it ...

Korth, Mrs.

2009-07-27

217

Values Drive the Plan  

ERIC Educational Resources Information Center

Values-integrated strategic planning provides the opportunity to clarify professional values as one envisions a future that is exciting and perhaps a bit provocative. This chapter explores the role and importance of student affairs and institutional values in strategic planning. It also looks at the historical roots of the profession and methods…

Cook, Les P.

2010-01-01

218

Values in Further Education.  

ERIC Educational Resources Information Center

This book explores educational values in the British further education system. Following an introductory discussion of educational values by the editor, John Halliday, the book contains 21 short essays organized in the areas of cultural values, curriculum, and management and staff development. The following are included: "Democratic…

Halliday, John, Ed.

219

Emergy and Nonmarket Value  

EPA Science Inventory

The purpose of this study is to better understand the differences and similarities between emergy and nonmarket economic valuation, when both are applied to value the same policies or development alternatives. The emdollar value of a good or service often exceeds the market value...

220

Values in the Curriculum.  

ERIC Educational Resources Information Center

Teaching for values instead of knowledge would significantly change education. Could the psychosocial values of goodness, beauty, search for truth, social organization, and economics be rank ordered? Can and how should such life-survival values as health, sex, aggression and self-defense, language, and love be taught in school? (Author/SB)

Wees, W. R.

1980-01-01

221

A comment on the market value of a room with a view  

Microsoft Academic Search

Views are very attractive to most people. Their monetary value is hard to quantify, however. Indications for the value of views are derived from the pricing of hotel rooms in Zürich, Switzerland. The higher price, which is charged for rooms with a view compared with those without a view, directly reflects the market value of the view. This type of

Eckart Lange; Peter V. Schaeffer

2001-01-01

222

Hard-on-Hard Lubrication in the Artificial Hip under Dynamic Loading Conditions  

PubMed Central

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. PMID:23940772

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

2013-01-01

223

The material co-construction of hard science fiction and physics  

NASA Astrophysics Data System (ADS)

This article explores the relationship between hard science fiction and physics and a gendered culture of science. Empirical studies indicate that science fiction references might spur some students' interest in physics and help develop this interest throughout school, into a university education and even further later inspire the practice of doing science. There are many kinds of fiction within the science fiction genre. In the presented empirical exploration physics students seem particularly fond of what is called `hard science fiction': a particular type of science fiction dealing with technological developments (Hartwell and Cramer in The hard SF renaissance, Orb/TOR, New York, 2002). Especially hard science fiction as a motivating fantasy may, however, also come with a gender bias. The locally materialized techno-fantasies spurring dreams of the terraforming of planets like Mars and travels in time and space may not be shared by all physics students. Especially female students express a need for other concerns in science. The entanglement of physics with hard science fiction may thus help develop some students' interest in learning school physics and help create an interest for studying physics at university level. But research indicates that especially female students are not captured by the hard techno-fantasies to the same extent as some of their male colleagues. Other visions (e.g. inspired by soft science fiction) are not materialized as a resource in the local educational culture. It calls for an argument of how teaching science is also teaching cultural values, ethics and concerns, which may be gendered. Teaching materials, like the use of hard science fiction in education, may not just be (yet another) gender bias in science education but also carrier of particular visions for scientific endeavours.

Hasse, Cathrine

2014-02-01

224

Relative importance of calcium and magnesium in hardness-based modification of copper toxicity  

SciTech Connect

Because of the relationship between water hardness and the toxicity of many metals, total hardness is used as a model parameter to calculate ambient water quality criteria for copper and other metals. However, the relative contribution of the Ca and Mg components of total hardness as modifiers of metals toxicity is not considered in the water quality criteria. Acute Cu toxicity was measured in rainbow trout (Oncorhynchus mykiss) and chinook salmon (O. tshawytscha) swim-up fry in laboratory waters that were formulated to have similar total hardness and alkalinity but different Ca and Mg concentrations. Experiments were performed at nominal total hardness values of 40 and 90 mg/L (as CaCO{sub 3}). In four paired toxicity tests, acute Cu toxicity was significantly lower, i.e., 96-h LC50s were higher, in laboratory waters containing proportionately more Ca (Ca:Mg molar ratios of 1.5--5.2) than in waters containing less Ca (Ca:Mg molar ratios of 0.2--0.8). the relative increase in the 96-h Cu LC50 at higher Ca concentrations, but similar total hardness concentrations, was between 29 and 86% when the low Ca treatment was similar to American Society for Testing and Materials laboratory water. Failure to account for differences in Ca when matching or adjusting for total hardness thus exerts an important influence on the prediction of metal toxicity. These differences must be addressed in water-effect ratio testing in which paired tests with laboratory and site waters are conducted.

Welsh, P.G.; Lipton, J.; Chapman, G.A.; Podrabsky, T.L.

2000-06-01

225

Hard X-ray Microscopic Images of the Human Hair  

SciTech Connect

The better visualization of the human organs or internal structure is challenging to the physicist and physicians. It can lead to more understanding of the morphology, pathophysiology and the diagnosis. Conventionally used methods to investigate cells or architectures, show limited value due to sample processing procedures and lower resolution. In this respect, Zernike type phase contrast hard x-ray microscopy using 6.95keV photon energy has advantages. We investigated hair fibers of the normal healthy persons. Coherence based phase contrast images revealed three distinct structures of hair, medulla, cortex, and cuticular layer. Some different detailed characters of each sample were noted. And further details would be shown and these results would be utilized as basic data of morphologic study of human hair.

Goo, Jawoong; Jeon, Soo Young; Oh, Tak Heon; Hong, Seung Phil; Lee, Won-Soo [Department of Dermatology and Institute of Hair and Cosmetic Medicine, Yonsei University Wonju College of Medicine, Wonju (Korea, Republic of); Yon, Hwa Shik [Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang (Korea, Republic of)

2007-01-19

226

Chronic toxicity of chloride to freshwater species: effects of hardness and implications for water quality guidelines.  

PubMed

Toxicity tests using nine freshwater species (Ceriodaphnia dubia, Daphnia magna, Oncorhynchus mykiss, Pimephales promelas, Lumbriculus variegatus, Tubifex tubifex, Chironomus dilutus, Hyallela azteca, and Brachionus calyciflorus) were conducted to evaluate their sensitivity to chloride. Acute-to-chronic ratios (ACRs) from these tests indicate the ACR of 7.59 employed by the United States Environmental Protection Agency (U.S. EPA) in deriving its water quality guideline for chloride may be conservative; a revised ACR of 3.50 is presented here. The endpoints used to calculate the ACR included 24-h to 96-h median lethal concentrations (LC50s) for acute tests, and 48-h to 54-d inhibition concentration (ICx) values for growth or reproduction for chronic exposures. Data from the present chronic toxicity tests, and other investigators, were used to propose a water quality guideline for long-term exposure to chloride using a species sensitivity distribution (SSD) approach. The 5th percentile from the SSD was calculated as 307?mg/L and proposed as the water quality guideline. Cladocerans were the most sensitive species in the dataset. Ceriodaphnia dubia was used to evaluate the relationship between water hardness and sensitivity to chloride. A strong relationship was observed and was used to establish a hardness-related equation to modify the proposed water quality guideline on the basis of water hardness, resulting in values ranging from 64?mg/L chloride at 10?mg/L hardness to 388?mg/L chloride at 160?mg/L hardness (as CaCO?). These data suggest that current water quality guidelines for chloride may be overly conservative in water with moderate-to-high hardness, and may not be sufficiently protective under soft-water conditions. PMID:20872898

Elphick, James R F; Bergh, Kelli D; Bailey, Howard C

2011-01-01

227

Hardness of FeB{sub 4}: Density functional theory investigation  

SciTech Connect

A recent experimental study reported the successful synthesis of an orthorhombic FeB{sub 4} 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 FeB{sub 4} using density functional theory. The electronic calculations show the good metallicity and covalent Fe–B bonding. Meanwhile, we extensively investigated stress-strain relations of FeB{sub 4} 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 FeB{sub 4} 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 FeB{sub 4} is a hard material and unlikely to become superhard (>40 GPa)

Zhang, Miao; Du, Yonghui; Gao, Lili [Department of Physics, Beihua University, Jilin 132013 (China)] [Department of Physics, Beihua University, Jilin 132013 (China); Lu, Mingchun [Department of Aeronautical Engineering Professional Technology, Jilin Institute of Chemical Technology, Jilin 132102 (China)] [Department of Aeronautical Engineering Professional Technology, Jilin Institute of Chemical Technology, Jilin 132102 (China); Lu, Cheng [Department of Physics, Nanyang Normal University, Nanyang 473061 (China)] [Department of Physics, Nanyang Normal University, Nanyang 473061 (China); Liu, Hanyu, E-mail: hal420@mail.usask.ca [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada)] [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada)

2014-05-07

228

Investigation of structural, dielectric, and magnetic properties of hard and soft mixed ferrite composites  

NASA Astrophysics Data System (ADS)

Barium ferrite (hard ferrite) and manganese nickel zinc ferrite (soft ferrite) were successfully synthesized by citrate gel combustion technique. They were used to form the composites by mixing them properly in required compositions (x)BaFe12O19-(1-x)Mn0.2Ni0.4Zn0.4Fe2O4 (0 ? x ? 1). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to investigate the different structural and morphological parameters of pure and mixed ferrite composites. XRD and SEM results confirmed the coexistence of both phases in the composite material. Moreover, it has been observed that the composites were constituted by nanosized particles. Structure of pure soft ferrite was found to be cubic and that of pure hard ferrite was hexagonal. Dielectric constant (?' and ??) and dielectric loss (tan ?) were analyzed as a function of frequency and composition and the behaviour is explained on the basis of Maxwell-Wagner model. It was observed that the dielectric loss decreases with the increase of hard ferrite content in the composite material. Magnetic measurements suggest the exchange coupling between the magnetizations of soft and hard ferrite grains. It has been observed that the coercivity increases with the increase of the volume of the hard phase in the composite material after an optimal value.

Kotnala, R. K.; Ahmad, Shahab; Ahmed, Arham S.; Shah, Jyoti; Azam, Ameer

2012-09-01

229

Increased Young's Modulus and Hardness of Col1a2oim Dentin  

PubMed Central

Mice harboring the Col1a2oim mutation (oim) express dentinogenesis imperfecta. To determine the effect of Col1a2 genotype on tissue mechanical properties, we compared Young's modulus and hardness of dentin in the 3 Col1a2 genotypes. Upper incisors were tested by nanoindentation. Genotype had a significant effect on Young's modulus, but there was not a simple mutant allele dosage relationship. The effect of genotype on hardness did not reach significance. Hardness and Young's modulus were greater near the dento-enamel junction than near the pulp chamber. Greater hardness and Young's modulus values near the dento-enamel junction reflected continued mineralization of the dentin following its initial synthesis. Analysis showed the mechanical data to be consistent with Fourier transform infrared and backscattered electron microscopy studies that revealed increased mineralization in oim bone. Analysis of the data suggests that clinical fragility of teeth in oim mice is not due to deficiencies of hardness or Young's modulus, but may be due to defects in post-yield behavior or resistance to fatigue damage. PMID:17062745

Lopez Franco, G.E.; Huang, A.; Pleshko Camacho, N.; Stone, D.S.; Blank, R.D.

2008-01-01

230

Spin effects in hard collision processes  

SciTech Connect

Questions of conservation and nonconservation of parity in phenomena associated with particle spin are reviewed. The main attention is concentrated on the production of hadrons, jets, and photons with large momentum transfer and the production of lepton pairs. The mechanisms of the hard-scattering subprocess include exchange of W/sup + -/ and Z/sup 0/ mesons, QCD and QED, and also interference between QCD and the weak interactions and between QED and the weak interactions. Effective cross sections of hard scattering processes are calculated, a factorization of the hadron--hadron scattering cross section is proposed, and the possible types of spin effects manifested in the hadronic subprocesses are classified and discussed. The properties of the polarized proton distributions and polarized structure functions are given in two appendices.

Ranft, G.; Ranft, J.

1984-05-01

231

Laser ablated hard coating for microtools  

DOEpatents

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

McLean, II, William (Oakland, CA); Balooch, Mehdi (Berkeley, CA); Siekhaus, Wigbert J. (Berkeley, CA)

1998-05-05

232

Measuring the fracture resistance of hard coatings  

NASA Astrophysics Data System (ADS)

A way of characterizing cracking in a hard coating is described. Microscale double cantilever beams have been made by focused ion beam milling and compressed in situ using a nanoindenter. The method can account for frictional effects and is demonstrated first on single crystals of SiC and GaAs of known toughness, before studying cracking in CrN-based hard coatings. It is found that ultra-fine grained CrAlN/Si3N4 coatings have a toughness approximately twice that of a conventional CrN coating. Although grain-size effects are still unclear, in situ observations directly show crack interactions with particles of Cr and voids in the film.

Liu, S.; Wheeler, J. M.; Howie, P. R.; Zeng, X. T.; Michler, J.; Clegg, W. J.

2013-04-01

233

Laser ablated hard coating for microtools  

DOEpatents

Wear-resistant coatings composed of laser ablated hard carbon films, are deposited by pulsed laser ablation using visible light, on instruments such as microscope tips and micro-surgical tools. Hard carbon, known as diamond-like carbon (DLC), films produced by pulsed laser ablation using visible light enhances the abrasion resistance, wear characteristics, and lifetimes of small tools or instruments, such as small, sharp silicon tips used in atomic probe microscopy without significantly affecting the sharpness or size of these devices. For example, a 10--20 nm layer of diamond-like carbon on a standard silicon atomic force microscope (AFM) tip, enables the useful operating life of the tip to be increased by at least twofold. Moreover, the low inherent friction coefficient of the DLC coating leads to higher resolution for AFM tips operating in the contact mode. 12 figs.

McLean, W. II; Balooch, M.; Siekhaus, W.J.

1998-05-05

234

Papillary cystadenocarcinoma of the hard palate.  

PubMed

Papillary cystadenocarcinoma (PCC) is an uncommon malignant tumour of the salivary gland, sometimes involving the minor salivary gland. Previously this entity was classified as an atypical type of adenocarcinoma, malignant papillary cystadenoma, low-grade papillary adenocarcinoma or mucus producing adenopapillary carcinoma. PCC is a glandular tumour with an indolent biological behaviour characterised by cysts and papillary endophytic projections. We report two cases of PCC involving the minor salivary gland of the hard palate. Both the patients presented with a swelling in the palate with difficulty in chewing. MRI revealed an extensively destructive lesion involving hard palate, alveolar ridge and maxillary antrum. Clinical and radiological features suggested the malignant nature of the lesion. Histopathology of incisional biopsy revealed tumour proliferation in a multicystic pattern, with extensive papillary proliferation. Diverse and cellular cytomorphology, and cellular and nuclear pleomorphism with few mitotic figures were the prominent features. Both the lesions were confirmed as PCC. PMID:24408937

Wanjari, Sangeeta Panjab; Wanjari, Panjab Vitthalrao; Patidar, Kalpana A; Parwani, Rajkumar N

2014-01-01

235

The underlying event in hard scattering processes  

SciTech Connect

The authors study the behavior of the underlying event in hard scattering proton-antiproton collisions at 1.8 TeV and compare with the QCD Monte-Carlo models. The underlying event is everything except the two outgoing hard scattered jets and receives contributions from the beam-beam remnants plus initial and final-state radiation. The data indicate that neither ISAJET or HERWIG produce enough charged particles (with p{sub T} > 0.5 GeV/c) from the beam-beam remnant component and that ISAJET produces too many charged particles from initial-state radiation. PYTHIA which uses multiple parton scattering to enhance the underlying event does the best job describing the data.

R. Field

2002-02-08

236

Fixed target electroweak and hard scattering physics  

SciTech Connect

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

Brock, R. (Michigan State Univ., East Lansing, MI (USA)); Brown, C.N.; Montgomery, H.E. (Fermi National Accelerator Lab., Batavia, IL (USA)); Corcoran, M.D. (eds.) (Rice Univ., Houston, TX (USA))

1990-02-01

237

Nanotwinned diamond with unprecedented hardness and stability  

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

238

Conformal Solution Theory: Hard-Sphere Mixtures  

Microsoft Academic Search

Conformal solution theory is examined. It is suggested that most difficulties associated with previous applications of this theory arise from the use of concentration-independent reference fluids. For the particular case of a hard-sphere mixture, it is shown that if the reference fluid is chosen so as to make the first-order term in the theory vanish, good results are obtained.

Douglas Henderson; Peter J. Leonard

1971-01-01

239

Radiation Hardness Assurance for Space Systems  

NASA Technical Reports Server (NTRS)

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 5. Section 6 presents the organization of the hardness assurance within a project. Section 7 discusses emerging radiation hardness assurance issues.

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

2002-01-01

240

Hard spheres on the gyroid surface  

PubMed Central

We find that 48/64 hard spheres per unit cell on the gyroid minimal surface are entropically self-organized. Striking evidence is obtained in terms of the acceptance ratio of Monte Carlo moves and order parameters. The regular tessellations of the spheres can be viewed as hyperbolic tilings on the Poincaré disc with a negative Gaussian curvature, one of which is, equivalently, the arrangement of angels and devils in Escher's Circle Limit IV. PMID:24098841

Dotera, Tomonari; Kimoto, Masakiyo; Matsuzawa, Junichi

2012-01-01

241

Nanotwinned diamond with unprecedented hardness and stability.  

PubMed

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. PMID:24919919

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

242

Hard Probes with the STAR Experiment  

Microsoft Academic Search

Recent results on the use of hard probes in heavy ion collisions by the STAR\\u000aexperiment at RHIC are reviewed. The increased statistical reach from RHIC run\\u000a4 and utilization of the full capabilities of the STAR experiment have led to a\\u000aqualitative improvement in these results. Light hadrons have been identified\\u000aout to transverse momenta ($p_T$) of 12 GeV\\/c,

J. C. Dunlop

2006-01-01

243

Captions for Deaf and Hard-of-Hearing Viewers  

MedlinePLUS

Home Health Info Hearing, Ear Infections, and Deafness Captions For Deaf and Hard-of-Hearing Viewers Captions For Deaf and Hard-of-Hearing Viewers On this page: What are captions? Open and closed captions Digital ...

244

Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm  

E-print Network

Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm Annual Status Report 2003 #12;Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm Annual Status Report 2003 Published: 14 May 2004

245

ENHANCING SEED AVAILABILITY FOR THE HARD CLAM (Mercenaria mercenaria)  

E-print Network

ENHANCING SEED AVAILABILITY FOR THE HARD CLAM (Mercenaria mercenaria) Leslie N. Sturmer Charles M Oceanographic Institution. #12;Enhancing Seed Availability For the Hard Clam (Mercenaria mercenaria) Aquaculture................................................................................................ 1 Clam Seed Availability

Florida, University of

246

Confined Hard Disk Two Piston System Model  

NSDL National Science Digital Library

The Confined Hard Disk Two Piston System simulates a constant-energy two-dimensional system of unit mass particles confined by two frictionless pistons of equal mass M. This computer model complements theoretical work describing the adiabatic expansion of an ideal gas using the quasi-static approximation. Users can set the number of particles N, their diameter and their initial particle kinetic energy. Slow-moving particles are color-coded as blue and fast particles are color-coded as yellow. The time evolution of temperature, pressure, and piston speed are shown in a second window.   Particles in this model have unit mass and interact through contact forces. Collision times are computed analytically because particles and pistons move with constant velocity between collisions. The time evolution algorithm advances the particle position from collision to collision until the requested time step is achieved. The time evolution is then paused, data is accumulated, and the screen is redrawn. The Confined Hard Disk Two Piston System was developed using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_stp_hd_ConfinedHardDiskTwoPistonSystem.jar file will run the program if Java is installed.

Christian, Wolfgang

2011-03-09

247

Solving the Hard Problem of Bertrand's Paradox  

E-print Network

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

Diederik Aerts; Massimiliano Sassoli de Bianchi

2014-06-27

248

The problem with value  

PubMed Central

Neural correlates of value have been extensively reported in a diverse set of brain regions. However, in many cases it is difficult to determine whether a particular neural response pattern corresponds to a value-signal per se as opposed to an array of alternative non-value related processes, such as outcome-identity coding, informational coding, encoding of autonomic and skeletomotor consequences, alongside previously described “salience” or “attentional” effects. Here, I review a number of experimental manipulations that can be used to test for value, and I identify the challenges in ascertaining whether a particular neural response is or is not a value signal. Finally, I emphasize that some non-value related signals may be especially informative as a means of providing insight into the nature of the decision-making related computations that are being implemented in a particular brain region. PMID:24726573

O’Doherty, John P.

2015-01-01

249

Requirements specification of distributed hard real-time operating systems  

Microsoft Academic Search

The authors present the requirements specification for distributed hard real-time operating systems used in time-critical, mission-oriented systems. For this purpose the relevant models for distributed hard real-time processing are established based on the general characteristics of distributed hard real-time systems. Following these models the requirements of a distributed hard real-time operating system are specified, and the major concerns in requirements

ManSang Chung; Heonshik Shin

1991-01-01

250

New York Sea Grant's Hard Clam Research Initiative  

NSDL National Science Digital Library

This New York Sea Grant website hosts the Hard Clam Research Initiative, a program launched in October 1999 to investigate the population dynamics of hard clams in Long Island's south shore estuary. The site features links to program information, the research projects involved, facts about hard clams and the hard clam industry, a list of publications, media links, and contact information. It also includes a "What's New" column that highlights current events associated with the project.

Paul C. Focazio

251

Design of Hard Water Stable Emulsifier Systems for Petroleum-  

E-print Network

Design of Hard Water Stable Emulsifier Systems for Petroleum- and Bio-based Semi for petroleum and bio-based MWFs that improve fluid lifetime by providing emulsion stability under hard water. The newly developed petroleum and bio-based formulations with improved hard water stability are competitive

Clarens, Andres

252

75 FR 4031 - Streamlining Hard-Copy Postage Statement Processing  

Federal Register 2010, 2011, 2012, 2013

...POSTAL SERVICE 39 CFR Part 111 Streamlining Hard-Copy Postage Statement Processing AGENCY...to reflect changes in the processing of hard-copy postage statements accompanying...Use Only'' section of, or round date, hard-copy postage statements (including...

2010-01-26

253

Hard metal lung disease in an oil industry worker.  

PubMed

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. PMID:20126930

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

254

THE ABUNDANCE AND DISTRIBUTION OF HARD CLAMS IN  

E-print Network

THE ABUNDANCE AND DISTRIBUTION OF HARD CLAMS IN NANTUCKET SOUND, MASSACHUSETTS 1958 Marine AND DISTRIBUTION OF HARD CLAMS IN NANTUCKET SOUND, MASSACHUSETTS, 1958 by John W. Ropes Fishery Research Biologist Samples for small hard clams 8 Observations on meat yield 9 Discussion 9 Conclusions 11 Literature cited

255

Geotechnical basis for underground energy storage in hard rock  

Microsoft Academic Search

Underground pumped hydroelectric storage requires the excavation of caverns in hard rock. Hard rock caverns, also, are one option for compressed air stoage. Preliminary design studies for both technologies at a specific site were completed. The geotechnical aspects of these storage systems are discussed from a generic viewpoint. Information about effective use of hard rock openings, including tunnels and shafts,

O. C. Farquhar

1982-01-01

256

Study of hot hardness characteristics of tool steels  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

257

Value contamination avoidance devices  

NASA Technical Reports Server (NTRS)

Mechanical redesign methods were used to minimize contamination damage of conventional fluid components and a contamination separator device was developed for long term reusable space vehicles. These were incorporated into an existing 50.8 mm poppet valve and tested for damage tolerance in a full size open loop flow system with gaseous and liquid nitrogen. Cyclic and steady flow conditions were tested with particles of 125 to 420 micrometers aluminum oxide dispersed in the test fluids. Nonflow life tests (100,000 cycles) were made with two valve configurations in gaseous hydrogen. The redesigned valve had an acceptable cycle life and improved tolerance to contamination damage when the primary sealing surfaces were coated with thin coatings of hard plastic (Teflon S and Kynar). Analytical studies and flow testing were completed of four different versions of the separator. overall separation efficiencies in the 55-90% range were measured with these non-optimum configurations.

Endicott, D. L.

1975-01-01

258

Looking for Core Values  

ERIC Educational Resources Information Center

People who view themselves as leaders, not just managers or teachers, are innovators who focus on clarifying core values and aligning all aspects of the organization with these values to grow their vision. A vision for an organization can't be just one person's idea. Visions grow by involving people in activities that help them name and create…

Carter, Margie

2010-01-01

259

Dance: Verities, Values, Visions.  

ERIC Educational Resources Information Center

The Binational Dance Conference was organized into three focal themes--verities, values, and visions in dance--to emphasize the known and accepted worth and value of dance, and to stimulate through knowledge and idea exchange, imaginative directions for dance in the future of both the United States and Canada. This thematic structure is also the…

Boorman, Joyce, Ed.; Harris, Dorothy, Ed.

260

Values Concepts and Techniques.  

ERIC Educational Resources Information Center

This book contains 29 articles for elementary and secondary teachers dealing with fundamental concepts and teaching techniques in values education. Part one of the book deals with concepts. Louis E. Raths examines valuing and its relationship to freedom and intelligence. The cognitive developmental approach to moral education is discussed by…

National Education Association, Washington, DC.

261

How I Taught Values  

ERIC Educational Resources Information Center

Values are principles or standards that people have decided are desirable to live by. The question of whether values can or should be taught to college students has been debated for decades, with the pros incorporating moral concepts into curricula and the antes scorning such efforts as not only inappropriate but also intellectually dull. In this…

Pratt, Annis

2005-01-01

262

More Place Value Activities  

NSDL National Science Digital Library

This webpage contains instructions for several activities and games designed to develop students' understanding of place value while reinforcing addition and subtraction skills. Downloadable materials and suggestions for variations are included along with links to online games. This is the second of two pages of similar activities. The first, Place Value Activities, is catalogued separately.

Terry Kawas

2010-01-01

263

High coking value pitch  

SciTech Connect

A high coking value pitch prepared from coal tar distillate and has a low softening point and a high carbon value while containing substantially no quinoline insolubles is disclosed. The pitch can be used as an impregnant or binder for producing carbon and graphite articles.

Miller, Douglas J.; Chang, Ching-Feng; Lewis, Irwin C.; Lewis, Richard T.

2014-06-10

264

Glycemic Index Values Database  

Cancer.gov

NCI has developed a listing of Glycemic Index (GI) values for individual foods. Food codes from the USDA Continuing Survey of Food Intakes of Individuals (CSFII) are used as a reference. This file provides GI values for those foods consumed by adults and queried on the DHQ or other FFQs used at NCI.

265

Sustaining NCTE Values  

ERIC Educational Resources Information Center

NCTE's core values, posted on the website (http://www.ncte.org), are writing, literature, diversity, integrated language arts, knowledgeable and caring teachers, advocacy, and public education ("NCTE Core Values"). In this article, the author focuses only on writing, diversity, and advocacy, considering just a few ways in which the organization…

Logan, Shirley Wilson

2011-01-01

266

Rosenak "Teaching Jewish Values"  

ERIC Educational Resources Information Center

Rosenak's "Teaching Jewish Values" (1986) is perhaps his most accessible book about Jewish education. After diagnosing the "diseases" of Jewish education, he endorses "teaching Jewish values" as the curricular strategy most likely to succeed given the chasm which divides traditional Jewish subject matter and the…

Resnick, David

2014-01-01

267

Customer Lifetime Value Measurement  

Microsoft Academic Search

The measurement of customer lifetime value is important because it is used as a metric in evaluating decisions in the context of customer relationship management. For a firm, it is important to form some expectations as to the lifetime value of each customer at the time a customer starts doing business with the firm, and at each purchase by the

Sharad Borle; Siddharth S. Singh; Dipak C. Jain

2008-01-01

268

Place Value Activities  

NSDL National Science Digital Library

This webpage contains instructions for several activities and games designed to develop students' understanding of place value while reinforcing addition and subtraction skills. Downloadable materials and suggestions for variations are included. A second page of additional activities is catalogued separately (More Place Value Activities).

Terry Kawas

2003-01-01

269

Art's Educational Value  

ERIC Educational Resources Information Center

This paper explores critically the nature of art's value in education and argues in favor of both intrinsic and instrumental value. Form and expression, while being out of favor in some contemporary circles, are re-claimed as appropriate features of art. Concepts and forms in art as elsewhere serve to structure impressions and experience and…

Richmond, Stuart

2009-01-01

270

The Fukui potential is a measure of the chemical hardness  

NASA Astrophysics Data System (ADS)

The chemical hardness is, after the chemical potential, the most important concept in describing the chemical reactivity of atoms and molecules. Recently, we showed that the Fukui potential at the nucleus of an atom is proportional to its hardness. Based on this, we speculated that the Fukui potential at the nucleus could be an alternative definition of the hardness. In this Letter we verify that the Fukui potential successfully describe the hardness of atoms. It is surprising that a property that depends only on the density at the nucleus can give such a good description of the chemical hardness.

Cárdenas, Carlos

2011-09-01

271

Hard-Soft-Hard Flare Spectra and Their Energy Dependence in Spectral Evolution of a Solar Hard X-Ray Flare  

NASA Astrophysics Data System (ADS)

In this Letter, we studied the time evolution of the energy-dependent spectral indices for the 2004 November 3 solar hard X-ray flare observed by RHESSI. The common soft-hard-soft (SHS) pattern spectra were found at the lower energies, while a new feature, hard-soft-hard (HSH), was found at higher energies for each subpeak. As the energy increases, the SHS pattern is gradually converted into the HSH pattern. Some possible explanations for the spectral evolution and its energy dependence are discussed, such as the return current.

Shao, Chengwen; Huang, Guangli

2009-04-01

272

CO2 laser milling of hard tissue  

NASA Astrophysics Data System (ADS)

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 ?m) with pulse duration of 50 - 100 ?s, 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.

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

2007-02-01

273

Hydrodynamics of self-propelled hard rods  

E-print Network

Motivated by recent simulations and by experiments on aggregation of gliding bacteria, we study a model of the collective dynamics of self-propelled hard rods on a substrate in two dimensions. The rods have finite size, interact via excluded volume and their dynamics is overdamped by the interaction with the substrate. Starting from a microscopic model with non-thermal noise sources, a continuum description of the system is derived. The hydrodynamic equations are then used to characterize the possible steady states of the systems and their stability as a function of the particles packing fraction and the speed of self propulsion.

Aparna Baskaran; M. Cristina Marchetti

2007-08-17

274

Hard metal lung disease and pneumothorax.  

PubMed

This case report describes a case of spontaneous pneumothorax in a metal grinder that failed to resolve with medical management. A lung biopsy taken during the subsequent thoracotomy revealed changes that were characteristic of giant cell interstitial pneumonia, as seen in hard metal disease. Pneumothorax has been described in many forms of interstitial lung disease but not in this type of occupational disease. Awareness of this possible association can result in: (1) the removal of an affected worker from his adverse work environment before advanced disease develops; and (2) the safe control of the work environment, to the advantage of other similarly exposed workers. PMID:9122508

Wahbi, Z K; Arnold, A G; Taylor, A J

1997-02-01

275

Classic Nintendo Games are (NP-)Hard  

E-print Network

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.

Aloupis, Greg; Guo, Alan

2012-01-01

276

A Microscale Spectrophotometric Determination of Water Hardness  

NASA Astrophysics Data System (ADS)

A spectrophotometric titration was performed to determine water hardness. The titration incorporated the traditional titration method employing EDTA as the titrant and calmagite as the indicator. The microscale experiment was carried out in a spectrometer cuvette and made use of a Texas Instruments (TI-83) calculator interfaced through a TI Calculator-Based Laboratory system to a Vernier colorimeter as the detector. Monitoring at 635 nm, one of the colorimeter's fixed wavelengths, was well suited for this analysis. Agreement was found with results from traditional titrations.

Gordon, James S.

2001-08-01

277

Evolutionary Algorithms for Hard Quantum Control  

E-print Network

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 to realize two fast quantum computing gates: a qutrit phase gate and a controlled-not gate. Then 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 delivers a superior control procedure because less time resolution is required for the control sequence.

Ehsan Zahedinejad; Sophie Schirmer; Barry C. Sanders

2014-03-04

278

Ground mechanics in hard rock mining  

SciTech Connect

Ground mechanics in hard rock mining represents a combination of applied science and mining engineering experience in ground control and excavation. The problems discussed reflect the present state of underground mining technology. Topics covered include the following: concepts of stress and strain; deformations of rocks; failure of rocks; strength of rocks; monitoring of rock structure; ground conditions; ground stresses; mine pillar structure; open stope structure; artificially supported stope structure; caving and drowning structure; combined open/filled structure; external ground support; internal ground support; and ground stabilization.

Jeremic, M.L.

1986-01-01

279

Structural properties of dense hard sphere packings.  

PubMed

We numerically study structural properties of mechanically stable packings of hard spheres (HS), in a wide range of packing fractions 0.53 ? ? ? 0.72. Detailed structural information is obtained from the analysis of orientational order parameters, which clearly reveals a disorder-order phase transition at the random close packing (RCP) density, ?c ? 0.64. Above ?c, the crystalline nuclei form 3D-like clusters, which upon further desification transform into alternating planar-like layers. We also find that particles with icosahedral symmetry survive only in a narrow density range in the vicinity of the RCP transition. PMID:25098389

Klumov, Boris A; Jin, Yuliang; Makse, Hernán A

2014-09-11

280

Economic Impact of the CommercialEconomic Impact of the CommercialEconomic Impact of the Commercial Hard Clam Culture IndustryHard Clam Culture IndustryHard Clam Culture Industry  

E-print Network

Hard Clam Culture IndustryHard Clam Culture IndustryHard Clam Culture Industry on the Economy;2 Introduction Commercially cultured hard clams have become the single most economically important food item sales of cultured hard clams have equaled or exceeded the growth realized by the more established

Florida, University of

281

Heat generation caused by ablation of dental hard tissues with an ultrashort pulse laser (USPL) system.  

PubMed

Heat generation during the removal of dental hard tissues may lead to a temperature increase and cause painful sensations or damage dental tissues. The aim of this study was to assess heat generation in dental hard tissues following laser ablation using an ultrashort pulse laser (USPL) system. A total of 85 specimens of dental hard tissues were used, comprising 45 specimens of human dentine evaluating a thickness of 1, 2, and 3 mm (15 samples each) and 40 specimens of human enamel with a thickness of 1 and 2 mm (20 samples each). Ablation was performed with an Nd:YVO4 laser at 1,064 nm, a pulse duration of 9 ps, and a repetition rate of 500 kHz with an average output power of 6 W. Specimens were irradiated for 0.8 s. Employing a scanner system, rectangular cavities of 1-mm edge length were generated. A temperature sensor was placed at the back of the specimens, recording the temperature during the ablation process. All measurements were made employing a heat-conductive paste without any additional cooling or spray. Heat generation during laser ablation depended on the dental hard tissue (enamel or dentine) and the thickness of the respective tissue (p?values in the 3-mm group (p?hard tissues (p?hard tissues, heat generation has to be considered. Especially during laser ablation next to pulpal tissues, painful sensations and potential thermal injury of pulp tissue might occur. PMID:23666547

Braun, Andreas; Krillke, Raphael Franz; Frentzen, Matthias; Bourauel, Christoph; Stark, Helmut; Schelle, Florian

2015-02-01

282

Electronic and bonding analysis of hardness in pyrite-type transition-metal pernitrides  

NASA Astrophysics Data System (ADS)

Most commonly known hard transition-metal nitrides crystallize in rocksalt structure (B1). The discovery of ultraincompressible pyrite-type PtN2 10 years ago has raised a question about the cause of its exceptional mechanical properties. We answer this question by a systematic computational analysis of the pyrite-type PtN2 and other transition-metal pernitrides (MN2) with density functional theory. Apart from PtN2, the three hardest phases are found among them in the 3d transition-metal period. They are MnN2, CoN2, and NiN2, with computed Vickers hardness (HV) values of 19.9 GPa, 16.5 GPa, and 15.7 GPa, respectively. Harder than all of these is PtN2, with a HV of 23.5 GPa. We found the following trends and correlations that explain the origin of hardness in these pernitrides. (a) Charge transfer from M to N controls the length of the N-N bond, resulting in a correlation with bulk modulus, dominantly by providing Coulomb repulsion between the pairing N atoms. (b) Elastic constant C44, an indicator of mechanical stability and hardness is correlated with total density of states at EF, an indicator of metallicity. (c) Often cited monotonic variation of HV and Pugh's ratio with valence electron concentration found in rocksalt-type early transition-metal nitrides is not evident in this structure. (d) The change in M-M bond strength under a shearing strain indicated by crystal orbital Hamilton population is predictive of hardness. This is a direct connection between a specific bond and shear related mechanical properties. This panoptic view involving ionicity, metallicity, and covalency is essential to obtain a clear microscopic understanding of hardness.

Liu, Z. T. Y.; Gall, D.; Khare, S. V.

2014-10-01

283

Value of Information References  

DOE Data Explorer

This file contains a list of relevant references on value of information (VOI) in RIS format. VOI provides a quantitative analysis to evaluate the outcome of the combined technologies (seismology, hydrology, geodesy) used to monitor Brady's Geothermal Field.

Morency, Christina

284

Values in psychotherapy.  

PubMed

There is a tension between those who hold that psychotherapy is a scientific discipline and therefore "value-free," and those who believe that values are inherent in the nature of psychotherapy. Psychoanalysis has moved from a science-based ideology, through the ethical concerns of Melanie Klein, to a recognition of the "aesthetic" dimension--the creation of suitable forms that can contain psychological distress. From this latter perspective, the antagonism between religion and psychotherapy, initiated by Freud, becomes less acute. Action-based ethical systems, which ignore the inner world, are critically scrutinized. The evidence suggesting there is a relationship between good outcome in psychotherapy and shared values between therapist and client is reviewed. It is posited that through examination of the "ethical countertransference," therapists should become aware of their own value systems and how they influence practice. PMID:8886227

Holmes, J

1996-01-01

285

Place Value Made Simple  

NSDL National Science Digital Library

Students will read, write, and represent whole numbers from 0 - 1,000,000 using symbols, models, expanded form, and words. Base ten blocks, place value pocket charts, folded paper strips for expanded form accordions, and checks are used.

Service, National S.

2009-05-19

286

Value of Information References  

SciTech Connect

This file contains a list of relevant references on value of information (VOI) in RIS format. VOI provides a quantitative analysis to evaluate the outcome of the combined technologies (seismology, hydrology, geodesy) used to monitor Brady's Geothermal Field.

Morency, Christina

2014-12-12

287

Time Value of Money  

NSDL National Science Digital Library

This PowerPoint presentation from University of Tennessee's Suzan Murphy gives an excellent tutorial for the Time Value of Money, which is the concept that "money received sooner rather than later allows one to use the funds for investment or consumption purposes." The presentation focuses on methods of using a calculator (specifically Hewlett Packard 17B II calculator) to solve problems of Time Value. This easy-to-understand tutorial presents basic concepts, story problems, and solutions to the story problems.

288

Economic Value Added  

Microsoft Academic Search

\\u000a Economic Value Added, kurz EVA, ist eine Methode bei der Finanzanalyse, die eingesetzt wird, um zu messen, ob ein Unternehmen\\u000a über den Kapitalkosten der eingesetzten Assets Wert schafft. EVA misst den Wert, der in einer definierten Periode durch Erhöhung\\u000a von Margen oder den modifizierten Einsatz unter-\\/ungenutzter Assets generiert wird. Der Economic Value Added einer Periode\\u000a ergibt sich als Residualgewinn, wenn

Christian Schawel; Fabian Billing

289

Economic Value Added  

Microsoft Academic Search

Economic Value Added, kurz EVA, ist eine Methode bei der Finanzanalyse, die eingesetzt wird, um zu messen, ob ein Unternehmen\\u000a über den Kapitalkosten der eingesetzten Assets Wert schafft. EVA misst den Wert, der in einer definierten Periode durch Erhöhung\\u000a von Margen oder den modifizierten Einsatz unter-\\/ungenutzter Assets generiert wird. Der Economic Value Added einer Periode\\u000a ergibt sich als Residualgewinn, wenn

Christian Schawel; Fabian Billing

290

Savings Bonds Value Calculator  

NSDL National Science Digital Library

From the Federal Reserve Bank of New York, this site computes the redemption value of users's US savings bonds. Easy-to-use pull-down menus allow visitors to enter information such as the date of issue and face value of their Series E bonds, Series EE bonds, and Series S bonds. After entering the information, the Calculator will then show a chart of issue dates and denominations and actual worth of the bonds, if cashed within a set period of time.

291

A two-stage approach to relaxation in billiard systems of locally confined hard spheres  

E-print Network

We consider the three-dimensional dynamics of systems of many interacting hard spheres, each individually confined to a dispersive environment, and show that the macroscopic limit of such systems is characterized by a coefficient of heat conduction whose value reduces to a dimensional formula in the limit of vanishingly small rate of interaction. It is argued that this limit arises from an effective loss of memory. Similarities with the diffusion of a tagged particle in binary mixtures are emphasized.

Pierre Gaspard; Thomas Gilbert

2011-11-27

292

Influence of plastic deformation upon the half-width of engineering metallic materials in hard state  

Microsoft Academic Search

The half-width values of the X-ray diffraction profiles are frequently used to characterize the static strength of a strengthened surface, or the depth distribution of this mechanical parameter, in a strengthened surface layer, especially in a shot-peening affected layer. However, for the unpeened surface and the base material of the shot-peened specimen of an alloy steel treated in hard state,

J. B. Li; H. B. Xu; R. Chen; Z. G. Wang

1996-01-01

293

Influence of plastic deformation upon the half-width of engineering metallic materials in hard state  

Microsoft Academic Search

The half-width values of the X-ray diffraction profiles are frequently used to characterize the static strength of a strengthened\\u000a surface, or the depth distribution of this mechanical parameter, in a strengthened surface layer, especially in a shot-peening\\u000a affected layer. However, for the unpeened surface and the base material of the shot-peened specimen of an alloy steel treated\\u000a in hard state,

J. B. Li; H. B. Xu; R. Chen; Z. G. Wang

1996-01-01

294

Evaluation of hard coatings obtained on AISI D2 steel by thermo-reactive deposition treatment  

Microsoft Academic Search

Niobium carbide, vanadium carbide and iron boride layers were obtained on AISI D2 steel by thermo-reactive treatments in different borax baths, containing ferroniobium, ferrovanadium or ferrotitanium, and aluminum. Vickers microhardness and micro-abrasive (ball crater) wear tests were used to evaluate the tribologic properties of the layers. Hardness values of the niobium carbide layer and the vanadium carbide layer, having depths

C. K. N. Oliveira; C. L. Benassi; L. C. Casteletti

2006-01-01

295

Tetraphosphonated thiophene ligand: mixing the soft and the hard.  

PubMed

The synthesis of ligand L(T)H8, based on a thiophene framework containing two bis(aminomethyldiphosphonate) functions in the ortho position to the central sulfur atom, is described, together with the characterization of the intermediate compounds. The physico-chemical properties of the ligand were first studied by means of potentiometry and UV-Vis absorption spectrophotometric titrations to determine its pK values. Six successive equilibrium constants were determined in aqueous solutions. The same means were then used to quantify the interactions of the ligand with Ni(II), Cu(II) and Zn(II). Following the conventional Irving-Williams trend, L(T) was shown to have the highest affinity towards Cu(II) (log K(CuL(T)) = 16.11(3)), while Zn(II) and Ni(II) showed similar values (log K(ML(T)) = 10.81(8) and 10.9(1), respectively), revealing a large selectivity of L(T) toward Cu(II). Based on a combination of UV-Vis absorption spectroscopy and EPR measurements as a function of pH, along with DFT calculations, the coordination behavior of the hard phosphonate, medium amino and soft thiophene entities are questioned regarding their coordination to the Cu atom. PMID:24788186

Brandel, Jérémy; Lecointre, Alexandre; Kollek, Julien; Michel, Sylvia; Hubscher-Bruder, Véronique; Déchamps-Olivier, Isabelle; Platas-Iglesias, Carlos; Charbonnière, Loïc J

2014-06-28

296

Structure and biochemistry of mammalian hard keratin.  

PubMed

In this review, the structure and biological formation of hard alpha-keratin are drawn together. The hard keratins comprising wool, hairs, quills, hooves, horns, nails and baleen contain partly alpha-helical polypeptides which show homology with epidermal polypeptides only in the helical regions. These polypeptides (about 32 chains) are organized into intermediate filaments (IFs) of 7.5 nm diameter which are embedded in variable amounts of a matrix of non-helical cystine-rich proteins and glycine-tyrosine-rich proteins. The total number of proteins may exceed 100. In addition keratins contain a variety of lipid components. Wool and hair are produced in follicles in a multistep procedure. In the lower levels of the follicle, IFs without associated matrix are found. Subsequently matrix proteins are laid down between the IFs and further synthesis takes place concurrently. Finally the proteins are insolubilized by the oxidative formation of disulphide bonds. Keratinized fibres shows considerable complexity and diversity in the structural arrangement of IFs and matrix within cortical cells. Typically the IFs show hexagonal packing or give a whorl-like appearance in cross-section. PMID:1714783

Marshall, R C; Orwin, D F; Gillespie, J M

1991-01-01

297

Lasers and hard-tissue interactions  

NASA Astrophysics Data System (ADS)

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

Makropoulou, Mersini I.; Papagiakoumou, Eirini I.

2004-06-01

298

Effects of explosions in hard rocks  

SciTech Connect

This work relates to explosions in hard rocks (ex: basalt, granite, limestone{hor_ellipsis}). Hard rock masses typically have a blocky structure created by the existence of geologic discontinuities such as bedding contacts, faults, and joints. At very high pressure-hundreds of kilobars and above-these discontinuities do not act separately, and the rock appears to be an equivalent continuous medium. At stress of a few tens of kilobars and below, the geologic discontinuities control the kinematics of the rock masses. Hence, the simulation of rock dynamics, anywhere but in the very-near source region, should account for those kinematics. In the very high pressure range continuum-based analysis is appropriate. In the discrete motion range one could consider: an equivalent continuum approach with anisotropy and plasticity. However, this is unlikely to provide the right kinematics; embedding discontinuities in continuum models, such as using joint elements and slip surfaces in finite elements. Typically, these are limited in terms of the separation of elements which may reconnect arbitrarily to new elements; complete discrete methods; ex: discrete elements, discontinuous displacement analysis (DDA). Discrete elements have progressed further than DDA We have chosen to develop and apply discrete elements models to explosion phenomenology in rocks.

Heuze, F.E.; Walton, O.R.; Maddix, D.M.; Shaffer, R.J.; Butkovich, T.R.

1993-05-01

299

Consciousness in Robots: The Hard Problem and Some Less Hard Problems (Extended Version)  

Microsoft Academic Search

Based on results from evolutionary psychology we discuss important func- tions that can be served by consciousness in autonomous robots. We distinguish intrinsic intentionality from consciousness, but argue it is also important. Fi- nally we explore the Hard Problem for robots (i.e., whether they can experience subjective awareness) from the perspective of the theory of protophenomena.

Bruce J. MacLennan

300

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

ERIC Educational Resources Information Center

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…

Song, H. Rosi

2009-01-01

301

The Hard X-ray Spectral Evolution in XRBs, AGNs and ULXs  

E-print Network

We explore the relationship between the hard X-ray photon index $\\Gamma$ and the Eddington ratio (\\xi=L_{X}(0.5-25 keV)/L_{Edd}) in six XRBs. We find that different XRBs follow different anti-correlations between $\\Gamma$ and $\\xi$ when $\\xi$ is less than a critical value, while they follow the same positive correlation when $\\xi$ is larger than the critical value. This anti-correlation and positive correlation are also found in LLAGNs and QSOs respectively, and the anti-correlation and positive correlation of different XRBs roughly converge to the same point ($\\log \\xi=-2.1, \\Gamma=1.5$), which may correspond to the accretion mode transition, since that the anti-correlation and positive correlation are consistent with the prediction of ADAFs and standard disk/corona system respectively. The traditional low/hard state are divided into two parts by the cross point $\\log \\xi\\sim-2.1$, i.e., faint-hard state in the anti-correlation part and bright-hard state in the positive correlation part. The accretion process in the bright-hard state may be still the standard accretion disk as that in the high/soft state, which is consistent with that both the cold disk component and broad Fe K emission line are observed in some bright-hard state of XRBs. The ADAF is only important in the faint-hard state XRBs. Motivated by the similarities of the state transition and timing properties of the ULXs to that of XRBs, we then constrain the BH masses for seven luminous ULXs assuming that their X-ray spectral evolution is similar to that of XRBs. We find that the BH masses of these seven ULXs are around $10^{4}M_sun$, which are typical intermediate mass BHs (IMBHs). Our results are roughly consistent with the BH masses constrained from the model fitting with a multi-color disk and/or the timing properties(e.g., QPO and break frequency).

Qingwen Wu; Minfeng Gu

2008-12-17

302

Annealing of Co-Cr dental alloy: effects on nanostructure and Rockwell hardness  

PubMed Central

PURPOSE The aim of the study was to evaluate the effect of annealing on the nanostructure and hardness of Co-Cr metal ceramic samples that were fabricated with a direct metal laser sintering (DMLS) technique. MATERIALS AND METHODS Five groups of Co-Cr dental alloy samples were manufactured in a rectangular form measuring 4 × 2 × 2 mm. Samples fabricated by a conventional casting technique (Group I) and prefabricated milling blanks (Group II) were examined as conventional technique groups. The DMLS samples were randomly divided into three groups as not annealed (Group III), annealed in argon atmosphere (Group IV), or annealed in oxygen atmosphere (Group V). The nanostructure was examined with the small-angle X-ray scattering method. The Rockwell hardness test was used to measure the hardness changes in each group, and the means and standard deviations were statistically analyzed by one-way ANOVA for comparison of continuous variables and Tukey's HSD test was used for post hoc analysis. P values of <.05 were accepted as statistically significant. RESULTS The general nanostructures of the samples were composed of small spherical entities stacked atop one another in dendritic form. All groups also displayed different hardness values depending on the manufacturing technique. The annealing procedure and environment directly affected both the nanostructure and hardness of the Co-Cr alloy. Group III exhibited a non-homogeneous structure and increased hardness (48.16 ± 3.02 HRC) because the annealing process was incomplete and the inner stress was not relieved. Annealing in argon atmosphere of Group IV not only relieved the inner stresses but also decreased the hardness (27.40 ± 3.98 HRC). The results of fitting function presented that Group IV was the most homogeneous product as the minimum bilayer thickness was measured (7.11 Å). CONCLUSION After the manufacturing with DMLS technique, annealing in argon atmosphere is an essential process for Co-Cr metal ceramic substructures. The dentists should be familiar with the materials that are used in clinic for prosthodontics treatments. PMID:24353888

Soylu, Elif Hilal; ?de, Semra; K?l?ç, Selim; Sipahi, Cumhur; Pi?kin, Bulent; Gökçe, Hasan Suat

2013-01-01

303

Modeling of the effect of freezer conditions on the hardness of ice cream using response surface methodology.  

PubMed

The effect of conventional continuous freezer parameters [mix flow (L/h), overrun (%), drawing temperature ( degrees C), cylinder pressure (kPa), and dasher speed (rpm)] on the hardness of ice cream under varying measured temperatures (-5, -10, and -15 degrees C) was investigated systematically using response surface methodology (central composite face-centered design), and the relationships were expressed as statistical models. The range (maximum and minimum values) of each freezer parameter was set according to the actual capability of the conventional freezer and applicability to the manufacturing process. Hardness was measured using a penetrometer. These models showed that overrun and drawing temperature had significant effects on hardness. The models can be used to optimize freezer conditions to make ice cream of the least possible hardness under the highest overrun (120%) and a drawing temperature of approximately -5.5 degrees C (slightly warmer than the lowest drawing temperature of -6.5 degrees C) within the range of this study. With reference to the structural elements of the ice cream, we suggest that the volume of overrun and ice crystal content, ice crystal size, and fat globule destabilization affect the hardness of ice cream. In addition, the combination of a simple instrumental parameter and response surface methodology allows us to show the relation between freezer conditions and one of the most important properties-hardness-visually and quantitatively on the practical level. PMID:19923588

Inoue, K; Ochi, H; Habara, K; Taketsuka, M; Saito, H; Ichihashi, N; Iwatsuki, K

2009-12-01

304

Wetlands Functions and Values  

NSDL National Science Digital Library

This learning module on wetland functions and values is the newest addition to the EPA's Watershed Academy Website (first reviewed in the January 19, 2000 Scout Report for Science & Engineering). The module explores the ecological and societal benefits and values that wetlands provide, such as "fish and wildlife habitats, natural water quality improvement, flood storage, shoreline erosion protection, opportunities for recreation and aesthetic appreciation," and much more. First-time users will find helpful instructions at "How to navigate this module;" the hyperlinked instructional text is also accompanied by useful color images. For anyone interested in wetland ecology, there is much to be learned (or reviewed) here.

2001-01-01

305

Wetlands Functions and Values  

NSDL National Science Digital Library

This learning module on wetland functions and values is the newest addition to the EPA's Watershed Academy Website. The module explores the ecological and societal benefits and values that wetlands provide, such as "fish and wildlife habitats, natural water quality improvement, flood storage, shoreline erosion protection, opportunities for recreation and aesthetic appreciation," and much more. First-time users will find helpful instructions at "How to navigate this module;" the hyperlinked instructional text is also accompanied by useful color images. For anyone interested in wetland ecology, there is much to be learned (or reviewed) here.

2007-07-30

306

Value of Information spreadsheet  

DOE Data Explorer

This spreadsheet represents the information posteriors derived from synthetic data of magnetotellurics (MT). These were used to calculate value of information of MT for geothermal exploration. Information posteriors describe how well MT was able to locate the "throat" of clay caps, which are indicative of hidden geothermal resources. This data is full explained in the peer-reviewed publication: Trainor-Guitton, W., Hoversten, G. M., Ramirez, A., Roberts, J., Júlíusson, E., Key, K., Mellors, R. (Sept-Oct. 2014) The value of spatial information for determining well placement: a geothermal example, Geophysics.

Trainor-Guitton, Whitney

307

Value of Information spreadsheet  

SciTech Connect

This spreadsheet represents the information posteriors derived from synthetic data of magnetotellurics (MT). These were used to calculate value of information of MT for geothermal exploration. Information posteriors describe how well MT was able to locate the "throat" of clay caps, which are indicative of hidden geothermal resources. This data is full explained in the peer-reviewed publication: Trainor-Guitton, W., Hoversten, G. M., Ramirez, A., Roberts, J., Júlíusson, E., Key, K., Mellors, R. (Sept-Oct. 2014) The value of spatial information for determining well placement: a geothermal example, Geophysics.

Trainor-Guitton, Whitney

2014-05-12

308

Nutritive Value of Fall-Grown Cereal-Grain Forages Over Time  

Technology Transfer Automated Retrieval System (TEKTRAN)

Changes in nutritive value of fall-grown cereal-grain forages over time can affect cattle performance. The objective of this study was to evaluate nutritive values of various fall-grown cereal-grain forages over time. One variety each of hard red (HR) and soft red (SR) winter wheat (Triticum aesti...

309

The potential energy landscape and inherent dynamics of a hard-sphere fluid  

E-print Network

Hard-sphere models exhibit many of the same kinds of supercooled-liquid behavior as more realistic models of liquids, but the highly non-analytic character of their potentials makes it a challenge to think of that behavior in potential-energy-landscape terms. We show here that it is possible to calculate an important topological property of hard-sphere landscapes, the geodesic pathways through those landscapes, and to do so without artificially coarse-graining or softening the potential. We show, moreover, that the rapid growth of the lengths of those pathways with increasing packing fraction quantitatively predicts the precipitous decline in diffusion constants in a glass-forming hard-sphere mixture model. The geodesic paths themselves can be considered as defining the intrinsic dynamics of hard spheres, so it is also revealing to find that they (and therefore the features of the underlying potential-energy landscape) correctly predict the occurrence of dynamic heterogeneity and non-zero values of the non-Gaussian parameter. The success of these landscape predictions for the dynamics of such a singular model emphasizes that there is more to potential energy landscapes than is revealed by looking at the minima and saddle points.

Qingqing Ma; Richard M. Stratt

2014-08-13

310

Hard X-ray spectra of cosmic gamma-ray bursts  

NASA Technical Reports Server (NTRS)

Hard X-ray measurements of six gamma-ray bursts observed during the period from October 1969 to April 1971 are presented. The measurements were made with detectors on the OGO-5 and OSO-6 satellites. Spectra for five of the six bursts have been determined using measurements from both satellites in order to reduce ambiguities due to uncertain source locations. A significant fraction, about 20-60%, of the energy of the bursts falls in the hard X-ray range (20-130 keV). The time-integrated spectra have been fitted by power-law, exponential, and thermal-bremsstrahlung functions. They are consistent with power laws which steepen at energies of at least 150 keV, as reported earlier for two other bursts. Evidence for spectral variability from event to event in the hard X-ray region is presented. For a power-law representation, the power-law index has values ranging from approximately unity to 2.5. The hard X-ray spectra of the gamma-ray bursts differ significantly from those of the recently discovered 1-15-keV X-ray bursts.

Kane, S. R.; Share, G. H.

1977-01-01

311

The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels  

PubMed Central

The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1?mm and 7?mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets. PMID:24526883

Davis, Claire

2014-01-01

312

The influence of wheel/rail contact conditions on the microstructure and hardness of railway wheels.  

PubMed

The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an "in-service" wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets. PMID:24526883

Molyneux-Berry, Paul; Davis, Claire; Bevan, Adam

2014-01-01

313

R-values  

SciTech Connect

I'll try to keep this short and simple. R{sub LANL} = (beta cpm of X{sub exp} on system 'A')/ (beta cpm of {sup 99}Mo{sub exp} on system 'A')/ (beta cpm of X on system 'A', from thermal on {sup 235}U)/ (beta cpm of {sup 99}Mo on system 'A', from thermal on {sup 235}U). As I understand it, the above equation is the historical (as well as current) way of determining R-values using data from beta counting at LANL. The ratio in the denominator, a little 'r', is the 'baseline' or 'calibration' value for a specific beta detector. Over time, if the detector 'drifts' one would see a variation in this 'r' during a thermal calibration measurement. This baseline is what LANL likes to track to monitor specific detector performance - this is not relevant to LLNL where gamma detection is used for determining R-values. LANL states that uncertainty is only dependent upon the count statistics for the isotopes measured. If one tries to convert this to an atom basis, the uncertainties will increase due to the incorporation of the uncertainties in the nuclear data used to convert the cpm to atoms. LLNL switched to gamma detection methods in the 1970s thus replacing our beta counting effort. The equation below is how we have since determined R-values. The numerator ratios atom values of isotopes that are determined by measuring gamma cpm (usually? using several peaks per isotope) and then converting to particle decay in dpm using detector efficiency for each peak and the appropriate branch ratio for each gamma emission. Isotope decay is then converted to atoms using specific activity, mass or volume?, and Avogadro's number. The denominator is simply the ratio of published, cumulative fission product chain yields for isotopes produced in a thermal irradiation on 235U - values of England & Ryder are used by LLNL for the NTNF program. Uncertainties in LLNL R-values are dependent upon gamma counting statistics as well as the nuclear data for each isotope. R{sub LLNL} = (Atoms of X{sub exp})/(Atoms of {sup 99}Mo{sub exp})/(Cumulative Fission Chain Yield of X, from thermal on {sup 235}U)/(Cumulative Fission Chain Yield of {sup 99}Mo, from thermal on {sup 235}U). The next page tabulates fission chain yields and 'atoms per gram' amounts measured in a recent NTNF Thermal Calibration. The R-values in the table are calculated using the LLNL method of determining R. The measure of success is demonstrated by how close to 1.00 the R-value is when determined during a Thermal Calibration. A value of 1.00 is the desired value. In the example below, only four isotopes lie outside of 1.00 by more than 3 percent. These are the four isotopic measurements that obviously need to be improved.

Roberts, K

2009-03-03

314

Surface Effects on Young's Modulud and Hardness of Fused Silica by Nanoindentation Study  

SciTech Connect

The surface Young's modulus (E) and hardness (H) of fused silica samples have been studied by nanoindentation. Two factors strongly affect the results of E and H. One factor is the polishing quality of the fused silica surface. Poor polishing quality produces much smaller E and H than the literature values for bulk fused silica. The second factor is surface flatness. Even for a well-polished silica surface, an "arch bridge effect" may hinder the measurements of the true values of E and H. A correction procedure is proposed to eliminate this effect, and the corrected results show substantial improvements.

Zheng, L.; Schmid, A.W.; Lambropoulos, J.C.

2007-01-24

315

Bottled drinking water: Water contamination from bottle materials (glass, hard PET, soft PET), the influence of colour and acidification  

E-print Network

Bottled drinking water: Water contamination from bottle materials (glass, hard PET, soft PET-QMS) in 294 samples of the same bottled water (predominantly mineral water) sold in the European Union, Nb and Cu. Antimony has a 21Ã? higher median value in bottled water when sold in PET bottles (0.33 vs

Short, Daniel

316

Bottled drinking water: water contamination from bottle materials (glass, hard PET, soft PET), the influence of colour and acidification  

E-print Network

Bottled drinking water: water contamination from bottle materials (glass, hard PET, soft PET- QMS) in 294 samples of the same bottled water (predominantly mineral water) sold in the European Union, Nb and Cu. Antimony has a 21x higher median value in bottled water when sold in PET-bottles (0.33 vs

Filzmoser, Peter

317

Prognostic Value of Multidetector Computed Tomography Coronary Angiography in Diabetes  

PubMed Central

OBJECTIVE To assess the prognostic role of multidetector computed tomography coronary angiography (MDCT-CA) in patients with diabetes with suspected coronary artery disease (CAD). Use of MDCT-CA is increasing in patients with suspected CAD. However, data supporting its prognostic value in patients with diabetes are limited. RESEARCH DESIGN AND METHODS Between January 2006 and September 2007, 429 consecutive diabetic patients were prospectively studied with MDCT-CA for detecting the presence and assessing the extent of CAD (disease extension and coronary plaque scores). Patients were classified according to the presence of normal coronary arteries and nonobstructive (<50%) and obstructive (?50%) coronary lesions. The composite rates of hard cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina) and all cardiac events (including revascularization) were the end points of the study. RESULTS Twenty-four patients were excluded because MDCT-CA data were not able to be interpreted. Of the remaining 405 patients, clinical follow-up (mean 62 ± 9 months) was obtained in 390 (98%). Multivariate analysis showed that predictors of hard and all events were obstructive CAD, three-vessel CAD, and left main coronary artery (LMCA) disease. Cumulative event-free survival was 100% for hard and all events in patients with normal coronary arteries, 78% for hard events and 56% for all events in patients with nonobstructive CAD, and 60% for hard events and 16% for all events in patients with obstructive CAD. Three-vessel CAD and LMCA disease were associated with a higher rate of hard cardiac events. CONCLUSIONS MDCT-CA provides long-term prognostic information for patients with diabetes with suspected CAD, showing excellent prognosis when there is no evidence of atherosclerosis and allowing risk stratification when CAD is present. PMID:23801796

Andreini, Daniele; Pontone, Gianluca; Mushtaq, Saima; Bertella, Erika; Conte, Edoardo; Baggiano, Andrea; Veglia, Fabrizio; Agostoni, Piergiuseppe; Annoni, Andrea; Formenti, Alberto; Montorsi, Piero; Ballerini, Giovanni; Bartorelli, Antonio L.; Fiorentini, Cesare; Pepi, Mauro

2013-01-01

318

Place Value Mathlets  

NSDL National Science Digital Library

This series of interactive JavaScript applets helps children understand place value in our base-10 system. The mathlets provide visual models of what happens as one counts by various powers of 10 in a progression from single units to tokens representing groups to a position-based numeration system. The resource includes an explanation of each applet.

2014-01-01

319

On weighted Shapley values  

Microsoft Academic Search

Nonsymmetric Shapley values for coalitional form games with transferable utility are studied. The nonsymmetries are modeled through nonsymmetric weight systems defined on the players of the games. It is shown axiomatically that two families of solutions of this type are possible. These families are strongly related to each other through the duality relationship on games. While the first family lends

E. Kalai; D. Samet

1987-01-01

320

Valuing Higher Education  

ERIC Educational Resources Information Center

The question of the value of higher education is today set in the context of an unprecedented banking and financial crisis. In this context of fundamental change and financial realignment, it is important that we as members of the university remake our case for why the university deserves to be considered alongside all those other worthy causes…

Pillay, Gerald J.

2009-01-01

321

Singular Value Decomposition  

E-print Network

. Exercise 6.1. Show that this is a valid inner product. Exercise 6.2. The trace of a matrix is the sum/4/9 page 86 i i i i 86 Chapter 6. Singular Value Decomposition the maximum amount of stretch possible matrix. Show the following additional facts, in light of the new norm definitions above. Exercise 6

Kilmer, Misha Elena

322

The Value-Form  

Microsoft Academic Search

Catholic teaching has always placed great emphasis on the value of work and of workers. Particularly since Pope John Paul II published Laborem Exercens, the philosophical and theological foundation for work's exalted position in Catholic thought is quite clear. Work is the way that human's participate in the Divine task of creation and contribute to the common good. In doing

Karl Marx

1978-01-01

323

Psychotherapy and religious values  

Microsoft Academic Search

Describes the alienation of therapeutic psychology from religious values in contrast to the growing professional and public interest in religious experience and commitment. Six theses aimed at broadening clinical psychology's scope to include religion more systematically in theories, research, and techniques, especially as they bear on personality and psychotherapy, are presented and documented. The theses include a contrast between dominant

Allen E. Bergin

1980-01-01

324

Nutritive Value of Foods.  

E-print Network

.......... '.' . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Tables I Equivalents by volume and weight ....................................................... . 2 Nutritive values of the edible part of foods: Dairy products ......................................................................... 4 Eggs... shown in table 2 are the amounts present in the edible part of the item, that is, in only that portion customarily eaten- corn without cob, meat without bone, potatoes without skin, European-type grapes without seeds. If additional parts are eaten...

Anoymous,

1982-01-01

325

Economic Value of Veterinary  

E-print Network

Economic Value of Veterinary Diagnostics Public Investment in Animal Health Testing Yields Economic Diagnostic Laboratory (TVMDL) works to protect animal and human health through diagnostic testing of samples of animals and products. In 2007, TVMDL performed 708,300 tests in support of $65.4 million in interstate

326

Valuing Differentiated Instruction  

ERIC Educational Resources Information Center

It is not enough to declare that differentiated instruction is going to be the order of the day. It also is not enough to call in a consultant and have teachers listen to a presentation about product, process, and assessment paradigms. Differentiated instruction is a practice that grows out of certain values that are important in the way school…

Benjamin, Amy

2006-01-01

327

Values destroyed by death  

Microsoft Academic Search

It was hypothesized that people who valued themselves highly (high self-esteem) should fear death more than those who do not, and what these people should fear most about death is the cessation of those activities in which they are greatly involved. These attitudes towards death should vary with such demographic variables as age, sex, social class, religion, and marital status.

James C. Diggory; Doreen Z. Rothman

1961-01-01

328

Making People Feel Valued.  

ERIC Educational Resources Information Center

Suggests many quick, easy and inexpensive ways to help make staff members of student publications feel valued and keep staff motivation levels high. Includes additional articles that describe how an editor can support efforts to motivate, suggest that staff retreats lead to success, note how banquets serve as reward, and suggest some favorite…

Fergueson, Susan; Aimone, Logan

2002-01-01

329

2010 Georgia Value Report  

E-print Network

t notable losses in %), sweet corn dow s and cabbage eac 0.46 million (-1.6% ns up $12.9 million tal cultural production ne in 2009. Six o rnamental Horticul test value and per es. Cotton was up ion (+8

Scott, Robert A.

330

Changing Values & Higher Education.  

ERIC Educational Resources Information Center

A transcript of a two-member panel discussion on changing values and higher education is presented. The transcript includes two speeches and members' responses to the questions of the moderator and audience. The first paper, presented by Robert Beagle (Assistant to the President, Edinboro State College, Pennsylvania) stresses that the key to…

Wagschal, Harry; Beagle, Robert

331

Transvaluation of Values.  

ERIC Educational Resources Information Center

The enthymeme--a syllogism in which one proposition is unexpressed--is adapted by the author to rhetorical analysis of movements and becomes the foundation for a theory of social change emphasizing social values and their historical transformation. Relating the enthymeme to the Burkean concepts of acceptance, rejection, casuistics stretching, and…

Purnell, Sandra E.

332

Economic Value Added  

Microsoft Academic Search

Economic Value Added (EVA), when applied properly in a company, impacts all departments and decisions. The equation for EVA as well as the adjustments that must be made to current accounting practices is the basis for an understanding of EVA. The success of EVA is displayed as companies that have implemented EVA to varying degrees are compared with companies that

Michael D Houle

2008-01-01

333

Decimal Place Value Recognition  

NSDL National Science Digital Library

You will learn to recognize decimal numbers and their word names. Now that you have been given instruction on converting decimal names to numerical value, you will be able to show your competency. Work through each section below. As you complete each section, before beginning the next section, show and report your scores to the teacher for credit. Section 1: ...

Mrs. Wells

2008-07-22

334

American Values Guide.  

ERIC Educational Resources Information Center

This social studies curriculum guide for grades 5 and 6 is a product of the American Values Exemplary Center directed by Ralph H. Davis. The introduction describes a model program to introduce students to the functioning of local and national government through a student government program set up as an essential part of the social studies…

Davis County School District, Farmington, UT.

335

Values and Society.  

ERIC Educational Resources Information Center

The idea of a democratic society based on human rights and social justice is the social issue examined in this book which is one of a series on challenges and choices in American values. The format followed in the series includes the following for secondary students: case studies illustrating the issue by focusing on human institutions, factual…

Nelson, Jack L.

336

Radiation Hardness Assurance (RHA) for Space Systems  

NASA Technical Reports Server (NTRS)

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.

Poivey, Christian; Buchner, Stephen

2007-01-01

337

Hard turning micro-machine tool  

DOEpatents

A micro-scale apparatus for supporting a tool for hard turning comprises a base, a pivot coupled to the base, an actuator coupled to the base, and at least one member coupled to the actuator at one end and rotatably coupled to the pivot at another end. A tool mount is disposed on the at least one member. The at least one member defines a first lever arm between the pivot and the tool mount, and a second lever arm between the pivot and the actuator. The first lever arm has a length that is less than a length of the second lever arm. The actuator moves the tool mount along an arc.

DeVor, Richard E; Adair, Kurt; Kapoor, Shiv G

2013-10-22

338

The Harding move: Opening up new horizons  

SciTech Connect

During July--September 1995 Dockwise successfully completed the unique load-out, transport and discharge operation of the 22,870 ton BP-Harding PDQ-unit (Production Drilling and Quarters) from Korea to the North Sea via the Suez Canal on board the self-propelled heavy-lift vessel Transshelf. This unique loading operation involved skidding the 22,870 ton platform via the side of the vessel over four skidbeams. Special solutions had to be found for stability, load spreading, mooring, ballasting and maneuvering. Due to the 2.6 meter grillage height, special procedures were required for maintaining stability during discharge by float-off. The experience gained in this project may lead to a further extension of load-out and transport possibilities on a worldwide scale, utilizing the presently available fleet of heavy-lift vessels.

Feith, J.; Hoekstra, R.J.P.

1996-12-31

339

Hard exclusive two photon processes in QCD  

NASA Astrophysics Data System (ADS)

This is a short review of some hard two-photon processes: (a) ?? ?Pbar1P2 ,Pbar1P2 = {?+?- ,K+K- ,KSKS ,?o?o ,?o ? } , (b) ?? ?V1V2 ,V1V2 = {?o?o , ?? , ?? , ?? } , (c) ?? ?baryon-antibaryon, (d) ?? ? ?Po ,Po = {?o , ? ,?? ,?c } . The available experimental data are presented. A number of theoretical approaches to calculation of these processes is described, both those based mainly on QCD and more phenomenological (the handbag model, the diquark model, etc.). Some theoretical questions tightly connected with this subject are discussed, in particular: the applications of various types of QCD sum rules, the endpoint behavior of the leading twist meson wave functions, etc.

Chernyak, Victor L.; Eidelman, Simon I.

2015-01-01

340

Escape Dynamics of Many Hard Disks  

E-print Network

Many-particle effects in escapes of hard disks from a square box via a hole are discussed in a viewpoint of dynamical systems. Starting from $N$ disks in the box at the initial time, we calculate the probability $P_{n}(t)$ for at least $n$ disks to remain inside the box at time $t$ for $n=1,2,\\cdots,N$. At early times the probabilities $P_{n}(t)$, $n=2,3,\\cdots,N-1$, are described by superpositions of exponential decay functions. On the other hand, after a long time the probability $P_{n}(t)$ shows a power-law decay $\\sim t^{-2n}$ for $n\

Tooru Taniguchi; Hiroki Murata; Shin-ichi Sawada

2014-03-26

341

Radiation hardness of the LHCb Outer Tracker  

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

342

Radiation hardness assurances categories for COTS technologies  

SciTech Connect

A comparison of the radiation tolerance of three commercial, and one radiation hardened SRAM is presented for four radiation environments. This work has shown the difficulty associated with strictly categorizing a device based solely on its radiation response, since its category depends on the specific radiation environment considered. For example, the 3.3-V Paradigm SRAM could be considered a radiation-tolerant device except for its SEU response. A more useful classification depends on the methods the manufacturer uses to ensure radiation hardness, i.e. whether specific design and process techniques have been used to harden the device. Finally, this work has shown that burned-in devices may fail functionally as much as 50% lower in total dose environments than non-burned-in devices. No burn-in effect was seen in dose-rate upset, latchup, or SEE environments. The user must ensure that total dose lot acceptance testing was performed on burned-in devices.

Hash, G.L.; Shaneyfelt, M.R.; Sexton, F.W.; Winokur, P.S.

1997-03-01

343

Dielectric and Hardness Measurements of Martian Analog Rocks in Support of the WISDOM Radar on ExoMars  

NASA Astrophysics Data System (ADS)

The success of the WISDOM (Water Ice and Subsurface Deposit Observation On Mars) radar in supporting the ExoMars drill to targets of opportunities and for maintaining optimal drilling capabilities is based on the complementarily of the two experiments in assessing the shallow subsurface physical properties. The dielectric properties as inverted from WISDOM wide-band ground penetrating radar radargrams, will be used to assess the ground mechanical properties as rock hardness, density and porosity which are crucial inputs for optimizing drilling operations. The main purpose of this research is to perform dielectric permittivity and hardness measurements for Martian analog rocks as a function of the Martian surface environmental parameters in an attempt to correlate between the physical and mechanical properties (i.e. dielectric constant and rock hardness) for volcanic rocks and permafrost simulating the case of the most upper layers of the Martian regolith. The implication for optimizing ExoMars drilling and sampling activities based on this correlation between the physical and mechanical properties will be discussed. We considered eight different types of volcanic rocks, for which we measured both the permittivity at the frequency band 200 to 1500 MHz and hardness over the range R= 10 to 100 using Schmidt hammer hardness tester. Based on our experimental results, the dielectric constant and hardness values ranged from (? = 1.91 to 8.09) and (R = 12.8 to 68) at the density of (? = 0.78 to 3 gm cm-3) for pumice and flood basalt respectively. Dielectric constant and rock hardness are found to increase with increasing sample density which implied a direct linear correlation between dielectric constant and rock hardness. The drill penetration rate of the previously described samples is predicted and correlated to the dielectric constant. An inverse relation between dielectric constant and drill penetration rate is concluded.

ElShafie, A.; Heggy, E.; Ciarletti, V.; Clifford, S. M.

2011-12-01

344

Radiation Hard AlGaN Detectors and Imager  

SciTech Connect

Radiation hardness of AlGaN photodiodes was tested using a 65 MeV proton beam with a total proton fluence of 3x10{sup 12} protons/cm{sup 2}. AlGaN Deep UV Photodiode have extremely high radiation hardness. These new devices have mission critical applications in high energy density physics (HEDP) and space explorations. These new devices satisfy radiation hardness requirements by NIF. NSTec is developing next generation AlGaN optoelectronics and imagers.

None

2012-05-01

345

Hardness and young's modulus of human peritubular and intertubular dentine  

Microsoft Academic Search

A specially modified atomic-force microscope was used to measure the hardness of fully hydrated peritubular and intertubular dentine at two locations within unerupted human third molars: within 1 mm of the dentine-enamel junction and within 1 mm of the pulp. The hardness of fully hydrated peritubular dentine was independent of location, and ranged from 2.23 to 2.54 GPa. The hardness

J. H. Kinney; M. Balooch; S. J. Marshall; G MARSHALLJR; T. P. Weihs

1996-01-01

346

Mechanical Properties of Chocolate: How Hard is your Chocolate?  

NSDL National Science Digital Library

Hardness is probably a concept you are well familiar with. You already know that certain materials are harder than others; in fact, you prove it everyday when you chew your food and your teeth don’t break (because your teeth are harder than the foods you chew). Hardness can be defined as a material's ability to resist a change in shape. Modern hardness testers take a well-defined shape and press it into a material with a certain force, observing the indent it leaves in the material when it is removed. In this lesson, you will be performing hardness testing on different bars of chocolate.

2007-12-20

347

Hardness of restorative resins: effect of camphorquinone, amine, and inhibitor.  

PubMed

The influence of the content of camphorquinone (CQ), amine (DABE), and inhibitor (MHQ) on the Wallace indentation hardness of light-curing polymers was investigated. The hardness was measured on disc-shaped specimens made from 50 bisphenol-A-glycidyl-dimethacrylate/triethyleneglycol-dimethacryla te-based monomers with various contents of CQ, DABE, and MHQ. When no MHQ had been added, the hardness number decreased with increasing content of CQ. This was also the case with increasing content of DABE, but to a lesser extent. In the presence of MHQ, the contents of CQ and DABE did not influence the hardness number significantly. PMID:2528883

Peutzfeldt, A; Asmussen, E

1989-08-01

348

Thermodynamics and kinetics of the crystal-melt interface for single and binary hard-sphere system: A simulation study  

NASA Astrophysics Data System (ADS)

The crystal-melt interfacial free energy, gamma, is the reversible work per unit area needed to create an interface between a crystal and its melt. The kinetic coefficient, mu, of crystal-melt interface is the ratio of the interface growth velocity to the undercooling (TM - T), where TM is the melting point. These two thermodynamic and kinetic parameters are very important in crystal growth. In this work we determine gamma and mu for the single and binary hard-sphere systems by analyzing capillary fluctuations in interface position using molecular dynamics (MD) simulation [Hoyt et al, Mat. Sci. Eng. R 41, 121-163 (2003)]. Our results of mu for the single hard-sphere system for the three orientations (100), (110), and (111) are in agreement with other simulation and experimental results for metals. The results we obtained give the relation mu100 > mu110 > mu111, which is also consistent with the ordering of experiments and simulations for metals, but is different from the ordering predicted by the density functional theory (DFT) for the hard-sphere system in which the orientation (110) is the lowest. Our results of gamma for the single hard-sphere is also consistent with the previous simulation results for the hard-sphere system, performed by two methods, cleaving method and fluctuation method. It also gives the relation gamma100 > gamma 110 > gamma111, which is also in agreement with the literature. Our simulation result for the binary hard-sphere system also gives the relation gamma 100 > gamma110 > gamma111. The interfacial free energy for the binary hard-sphere system is slightly higher than that for the single hard-sphere system, but after scaling its pressure to the pressure of the single hard-sphere system to keep the pressures the same, it becomes slightly smaller, which is in consistent with the gamma of the Cu-Ni alloy being slightly smaller than that of Ni. Our calculation for the mu of the binary hard-sphere system also gives the relation mu100 > mu 110 > mu111, and its values are smaller than that of the single hard-sphere system.

Amini, Majeed Abdul-Nabi

2006-12-01

349

Measuring Value in Healthcare  

E-print Network

A statistical description and model of individual healthcare expenditures in the US has been developed for measuring value in healthcare. We find evidence that healthcare expenditures are quantifiable as an infusion-diffusion process, which can be thought of intuitively as a steady change in the intensity of treatment superimposed on a random process reflecting variations in the efficiency and effectiveness of treatment. The arithmetic mean represents the net average annual cost of healthcare; and when multiplied by the arithmetic standard deviation, which represents the effective risk, the result is a measure of healthcare cost control. Policymakers, providers, payors, or patients that decrease these parameters are generating value in healthcare. The model has an average absolute prediction error of approximately 10-12% across the range of expenditures which spans 6 orders of magnitude over a nearly 10-year period. For the top 1% of the population with the largest expenditures, representing 20%-30% of total ...

Gardner, Christopher

2008-01-01

350

Complex-Valued Autoencoders  

PubMed Central

Autoencoders are unsupervised machine learning circuits, with typically one hidden layer, whose learning goal is to minimize an average distortion measure between inputs and outputs. Linear autoencoders correspond to the special case where only linear transformations between visible and hidden variables are used. While linear autoencoders can be defined over any field, only real-valued linear autoencoders have been studied so far. Here we study complex-valued linear autoencoders where the components of the training vectors and adjustable matrices are defined over the complex field with the L2 norm. We provide simpler and more general proofs that unify the real-valued and complex-valued cases, showing that in both cases the landscape of the error function is invariant under certain groups of transformations. The landscape has no local minima, a family of global minima associated with Principal Component Analysis, and many families of saddle points associated with orthogonal projections onto sub-space spanned by sub-optimal subsets of eigenvectors of the covariance matrix. The theory yields several iterative, convergent, learning algorithms, a clear understanding of the generalization properties of the trained autoencoders, and can equally be applied to the hetero-associative case when external targets are provided. Partial results on deep architecture as well as the differential geometry of autoencoders are also presented. The general framework described here is useful to classify autoencoders and identify general properties that ought to be investigated for each class, illuminating some of the connections between autoencoders, unsupervised learning, clustering, Hebbian learning, and information theory. PMID:22622264

Baldi, Pierre; Lu, Zhiqin

2012-01-01

351

Does the temperature of beverages affect the surface roughness, hardness, and color stability of a composite resin?  

PubMed Central

Objective: To investigate the effect of beverages’ temperature on the surface roughness, hardness, and color stability of a composite resin. Materials and Methods: Fifty specimens of the Filtek Z250 composite (3M ESPE, Dental Products, St.Paul, MN, USA) were prepared and initial roughness, microhardness, and color were measured. Then the specimens were randomly divided into five groups of 10 specimens each: Coffee at 70°C, coffee at 37°C, cola at 10°C, cola at 37°C, and artificial saliva (control). After the samples were subjected to 15 min × 3 cycles per day of exposure to the solutions for 30 days, the final measurements were recorded. Results: After immersion in beverages, the artificial saliva group showed hardness values higher than those of the other groups (P < 0.001) and the microhardness values were significantly different from the initial values in all groups except for the control group. Both cola groups showed roughness values higher than the baseline values (P < 0.05), while the other groups showed values similar to the baseline measurements. When ?E measurements were examined, the 70°C coffee group showed the highest color change among all the groups (P < 0.05). Conclusion: High-temperature solutions caused alterations in certain properties of composites, such as increased color change, although they did not affect the hardness or roughness of the composite resin material tested. PMID:24883021

Tuncer, Duygu; Karaman, Emel; Firat, Esra

2013-01-01

352

Relationships between hardness, Young's modulus and elastic recovery in hard nanocomposite coatings  

Microsoft Academic Search

The paper is devoted to an assessment of the mechanical behavior of hard and superhard nanocomposite coatings from loading\\/unloading curves measured by a computer-controlled Fischerscope H 100 microhardness tester and a maximum depth dmax of the diamond indenter impression into the coating at a given load L. It is shown that: (1) the area between the loading\\/unloading curve and the

J Musil; F Kunc; H Zeman; H Poláková

2002-01-01

353

New reference values for vitamin D.  

PubMed

In the recent past, many studies have been published on the association between vitamin D and bone health or the risk of various chronic diseases. Thus, the D-A-CH reference values [D-A-CH arises from the initial letters of the common country identification for the countries Germany (D), Austria (A) and Switzerland (CH)] for the intake of vitamin D have been revised based on a critical review by the German Nutrition Society. Both dietary intake and endogenous synthesis contribute to the body's vitamin D status. Since different factors modulate the extent of endogenous vitamin D formation, quantification is hardly possible. Therefore, the new reference values for vitamin D intake are specified for a situation in which endogenous synthesis is completely missing. Based on the findings of the critical review, serum 25-hydroxyvitamin D concentrations of 50 nmol/l or higher are considered an indicator of an optimal vitamin D status. When endogenous synthesis is missing, adequate vitamin D intake is estimated as 20 µg per day for children, adolescents and adults. Dietary vitamin D intake from habitual diet is not sufficient to achieve this value. This gap has to be covered by endogenous vitamin D synthesis and/or additional intake of vitamin D. It is clearly stated that the desired vitamin D supply can be achieved without using vitamin D supplements by frequent sun exposure. PMID:22677925

2012-01-01

354

Nanoindentation of soft films on hard substrates: Experiments and finite element simulations  

SciTech Connect

Experiments and finite element simulations have been performed to examine error measurement of hardness and elastic modulus caused by pile-up when soft films deposited on hard substrates are tested by nanoindentation methods. Pile-up is exacerbated in soft-film/hard-substrate systems by the constraint imposed on plastic deformation in the film by the relatively non-deformable substrate. To experimentally examine pile-up effects, soft aluminum films with thicknesses of 240, 650, and 1700 nm were deposited on hard soda-lime glass substrates and tested by nanoindentation techniques. This system is attractive because the elastic modulus of the film and the substrate are approximately the same, but the substrate is harder than the film by a factor of about ten. Consequently, substrate influences on the indentation load-displacement behavior are manifested primarily by differences in the plastic flow characteristics alone. The elastic modulus of the film/substrate system, as measured by nanoindentation techniques, exhibits an increase with indenter penetration depth which peaks at a value approximately 30% greater than the true film modulus at a penetration depth close to the film thickness. Finite element simulation shows that this unusual behavior is caused by substrate-induced enhancement of pile-up. Finite element simulation also shows that the amount of pile-up increases with increasing penetration depth, and that the pile-up geometry depends on the work-hardening characteristics of the film. Because of these effects, nanoindentation techniques overestimate the true film hardness and elastic modulus by as much as 68% and 35%, respectively, depending on the work-hardening behavior of the film and the indenter penetration depth. The largest errors occur in non-work-hardening materials at penetration depths close to the film thickness, for which substrate-induced enhancement of pile-up is greatest.

Pharr, G.M.; Tsui, T.Y. [Rice Univ., Houston, TX (United States). Dept. of Materials Science; Bolshakov, A. [Baker Hughes Inteq, Houston, TX (United States); Hay, J.C. [Oak Ridge National Lab., TN (United States)

1997-12-31

355

Influence of water hardness and sulfate on the acute toxicity of chloride to sensitive freshwater invertebrates.  

PubMed

Total dissolved solids (TDS) represent the sum of all common ions (e.g., Na, K, Ca, Mg, chloride, sulfate, and bicarbonate) in freshwater. Currently, no federal water quality criteria exist for the protection of aquatic life for TDS, but because the constituents that constitute TDS are variable, the development of aquatic life criteria for specific ions is more practical than development of aquatic life criteria for TDS. Chloride is one such ion for which aquatic life criteria exist; however, the current aquatic life criteria dataset for chloride is more than 20 years old. Therefore, additional toxicity tests were conducted in the current study to confirm the acute toxicity of chloride to several potentially sensitive invertebrates: water flea (Ceriodaphnia dubia), fingernail clams (Sphaerium simile and Musculium transversum), snail (Gyraulus parvus), and worm (Tubifex tubifex), and determine the extent to which hardness and sulfate modify chloride toxicity. The results indicated a significant ameliorating effect of water hardness (calcium and magnesium) on chloride toxicity for all species tested except the snail; for example, the 48-h chloride median lethal concentration (LC50) for C. dubia at 50?mg/L hardness (977?mg Cl(-) /L) was half that at 800?mg/L hardness (1,836?mg Cl(-) /L). Conversely, sulfate over the range of 25 to 600?mg/L exerted a negligible effect on chloride toxicity to C. dubia. Rank order of LC50 values for chloride at a given water hardness was in the order (lowest to highest): S. simile?

Soucek, David J; Linton, Tyler K; Tarr, Christopher D; Dickinson, Amy; Wickramanayake, Nilesh; Delos, Charles G; Cruz, Luis A

2011-04-01

356

Quantum Searches in a Hard 2SAT Ensemble  

E-print Network

Using a recently constructed ensemble of hard 2SAT realizations, that has a unique ground-state we calculate for the quantized theory the median gap correlation length values $\\xi_{GAP}$ along the direction of the quantum adiabatic control parameter $\\lambda$. We use quantum annealing (QA) with transverse field and a linear time schedule in the adiabatic control parameter $\\lambda$. The gap correlation length diverges exponentially $\\xi_{\\rm GAP} \\propto {\\rm exp} [+r_{\\rm GAP}N]$ in the median with a rate constant $r_{\\rm GAP}=0.553(6)$, while the run time diverges exponentially $\\tau_{\\rm QA} \\propto {\\rm exp} [+r_{\\rm QA}N]$ with $r_{\\rm QA}=1.184(16)$. Simulated classical annealing (SA) exhibits a run time rate constant $r_{\\rm SA}=0.340(5)$ that is small and thus finds ground-states exponentially faster than QA. There are no quantum speedups in ground state searches on constant energy surfaces that have exponentially large volume. We also determine gap correlation length distribution functions $P(\\xi_{\\rm GAP})d\\xi_{\\rm GAP} \\approx W_k$ over the ensemble that at $N=18$ are close to Weibull functions $W_k$ with $k \\approx 1.2$ i.e., the problems show thin catastrophic tails in $\\xi_{\\rm GAP}$. The inferred success probability distribution functions of the quantum annealer turn out to be bimodal.

Neuhaus Thomas

2014-12-17

357

Hard-spin mean-field theory of a three-dimensional stacked-triangular-lattice system  

SciTech Connect

Closed form solutions to the hard-spin mean-field equations are constructed for the three-dimensional stacked triangular system. The phase diagram of this system is examined. The free energy of the system is calculated within the same approximation to identify the thermodynamically stable states in the phase diagram. A second-order phase transition line is found to exist for very small values of the external field. Our results display the details of the structure of the multicritical region within the hard-spin mean-field theory approximation.

Akguec, G.B.; Cemal Yalabik, M. (Department of Physics, Bilkent University, Ankara (Turkey))

1995-03-01

358

Prediction of tablet hardness based on near infrared spectra of raw mixed powders by chemometrics.  

PubMed

The purpose of this research is to elucidate the effect of lubricant mixing on tablet hardness by near-infrared (NIR) chemometrics as a basic study of process analytical technology. Formulation cellulose (F-C) consisted of sulpyrine (SP), microcrystalline cellulose (MC), and magnesium stearate (MgSt). Formulation lactose/starch (F-L) consisted of SP bulk drug powder, spray-dried lactose (SL), corn starch (CS), and MgSt. First, F-L and F-C without MgSt were mixed in a twin-shell mixer for 60 min. MgSt was added to the mixed powder, and was mixed for various mixing times, after which the mixed powders were compressed by 8-mm diameter punch and die. NIR spectra of raw mixed powders of F-L and F-C were taken using a reflection type of Fourier transform NIR spectra spectrometer, and chemometric analysis was performed using principal component regression (PCR). The tablet hardnesses of F-L and F-C decreased with increasing mixing time. All NIR spectra of the mixed powders of F-L and F-C fluctuated depending on mixing time. In order to predict tablet hardness before tablet compression, NIR spectra of F-L and F-C mixed powders were analyzed and evaluated for hardness by PCR. The minimum standard error of cross-validation values could be realized by using five- and six-principal component models, respectively. In the cases of F-L and F-C, the relationships between the actual and predicted tablet hardnesses showed straight lines, respectively. In the regression vectors of F-L and FC, the peaks related to hydrogen groups of SP, CS, and MC appeared as positive peaks. In contrast, the peaks related to hydrocarbon due to MgSt appeared as negative peaks in the regression vectors. The calibration models to evaluate the tablet hardness were obtained based on NIR spectra of raw mixed powders by PCR. This approach to predicting tablet hardness prior to compression could be used as a routine test to indicate the quality of the final product without spending time and energy to produce samples of questionable quality. PMID:16721793

Otsuka, Makoto; Yamane, Ikuro

2006-07-01

359

Effects of water hardness and existence of adsorbent on toxic surface tension of surfactants for aquatic species.  

PubMed

We have studied the effectiveness of surface tension on surfactants risk assessment. gamma(tox) was defined as surface tension at a point where acute aquatic toxicity of a surfactant emerges. Oryzias latipes, Daphnia magna, and Podocopida were used for acute aquatic toxicity test of 7 surfactants and 3 detergents. Gamma(tox)values were plotted on surface tension curves, and the effect of water hardness on toxicity and surface tension were examined. Results showed that gamma(tox) varies greatly by kind of surfactant or detergent. Therefore, aquatic toxicity cannot only be explained by surface tension. The change of aquatic toxicity with varying water hardness, however, could be explained by the change of surface tension. Aquatic toxicity of LAS (Linear Alkylbenzene Sulphonate) increased and aquatic toxicity of SOAP decreased with an increase of water hardness, but both gamma(tox), values were constant. Aquatic toxicity was decreased by an addition of mud soil as adsorbent into surfactant solution. The toxicity change can be explained by the surface tension since gamma(tox) value of solution with and without mud soil were equal. These results showed that the change of aquatic toxicity of a surfactant caused by water property, such as water hardness, could be explained by the change of surface tension. PMID:17898487

Oya, Masaru; Orito, Shintaro; Ishikawa, Yusuke; Iizuka, Tomoko

2007-01-01

360

Trade in Value Added and the Valued Added in Trade  

Microsoft Academic Search

This paper discussed two measures of value added flows between countries ‘Trade in value added’ accounts for value added of one country directly and indirectly embodied in final consumption of another country. ‘Value added in trade’ measures the value added embodied in gross trade flows. The paper shows that both measures result in the same overall net trade of a

Robert Stehrer

2012-01-01

361

Puroindolines: the molecular genetic basis of wheat grain hardness  

Microsoft Academic Search

The variation in grain hardness is the single most important trait that determines end-use quality of wheat. Grain texture classification is based primarily on either the resistance of kernels to crushing or the particle size distribution of ground grain or flour. Recently, the molecular genetic basis of grain hardness has become known, and it is the focus of this review.

Craig F. Morris

2002-01-01

362

Material hardness and ageing measurement using guided ultrasonic waves.  

PubMed

Elastic properties of materials can be easily determined from the ultrasonic wave velocity measurement. However, material hardness cannot be obtained from the ultrasonic wave speed. Heat treatment and ageing affect the microstructure of many materials changing their hardness and strength. It has been already established that ultrasonic attenuation and dispersion are also affected by the material microstructure. It is investigated in this paper if the attenuation of ultrasonic guided waves can be correlated with the material ageing or duration of heat treatment and material hardness. To this aim six identical aluminum 2024 alloy plate specimens were subjected to different durations of heat treatment at 150°C and were inspected nondestructively propagating Lamb waves through the specimens. Attenuation of the Lamb wave was found to be inversely related to the hardness. Rockwell hardness test was performed to corroborate the ultrasonic observations. In comparison to the Rockwell hardness test the ultrasonic inspection was found to be more sensitive to the heat treatment duration and material ageing. From these results it is concluded that guided wave inspection method is a reliable and probably more desirable alternative for characterizing the hardness and microstructure of heat treated materials. Earlier investigations correlated the bulk wave attenuation with the material ageing while this work is the first attempt to correlate the guided wave attenuation to the material hardness and ageing. PMID:23047018

Korde, Nilesh; Kundu, Tribikram

2013-02-01

363

Effect of Loading Rate Upon Conventional Ceramic Microindentation Hardness  

Microsoft Academic Search

The world standards for conventional ceramic hardness have varying require- ments for control of loading rate during the indentation cycle. A literature review suggests that loading rate may affect measured hardness in some instances. In view of the uncertainty over this issue, new experiments over a range of indenta- tion loading rates were performed on a steel, sintered silicon carbide,

George D. Quinn; Parimal J. Patel

364

A NEW MODEL FOR PERFORMANCE PREDICTION OF HARD ROCK TBMS.  

E-print Network

Chapter 50 A NEW MODEL FOR PERFORMANCE PREDICTION OF HARD ROCK TBMS. By: Jamal Rostami1 and Levent ABSTRACT A new theoretical/empirical model has been developed for performance predic- tion of hard rock TBMs. The model uses information on the rock properties and cutting geometry to calculate TBM rate

365

36 CFR 13.1308 - Harding Icefield Trail.  

... § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the junction with the main paved trail near Exit Glacier to the emergency hut near the terminus is closed to— (a) Camping within 1/8 mile of the trail from March 1...

2014-07-01

366

36 CFR 13.1308 - Harding Icefield Trail.  

Code of Federal Regulations, 2012 CFR

... § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the junction with the main paved trail near Exit Glacier to the emergency hut near the terminus is closed to— (a) Camping within 1/8 mile of the trail from March 1...

2012-07-01

367

36 CFR 13.1308 - Harding Icefield Trail.  

Code of Federal Regulations, 2010 CFR

... § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the junction with the main paved trail near Exit Glacier to the emergency hut near the terminus is closed to— (a) Camping within 1/8 mile of the trail from March 1...

2010-07-01

368

36 CFR 13.1308 - Harding Icefield Trail.  

Code of Federal Regulations, 2011 CFR

... § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the junction with the main paved trail near Exit Glacier to the emergency hut near the terminus is closed to— (a) Camping within 1/8 mile of the trail from March 1...

2011-07-01

369

36 CFR 13.1308 - Harding Icefield Trail.  

Code of Federal Regulations, 2013 CFR

... § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the junction with the main paved trail near Exit Glacier to the emergency hut near the terminus is closed to— (a) Camping within 1/8 mile of the trail from March 1...

2013-07-01

370

Compressing nearly hard sphere fluids increases glass fragility  

E-print Network

OFFPRINT Compressing nearly hard sphere fluids increases glass fragility L. Berthier and T. A.1209/0295-5075/86/10001 Compressing nearly hard sphere fluids increases glass fragility L. Berthier1(a) and T. A. Witten2 1 to that of a very fragile glass as increases beyond 0. Correlations between fragility and various physical

Berthier, Ludovic

371

Hard X-ray properties of magnetic cataclysmic S. Scaringi  

E-print Network

, Roma, Italy Abstract. We have constructed a new sample of magnetic cataclysmic variables (mCVs CVs and included mCVs observed with either Swift/BAT or SUZAKU/HXD. Here we review the properties arising from this hard X-ray selected sample and find that most hard X-ray detected mCVs have Pspin

Norton, Andrew J.

372

HARD CLAMS (Mercenaria mercenaria) EVALUATE PREDATION RISK USING CHEMICAL SIGNALS  

E-print Network

HARD CLAMS (Mercenaria mercenaria) EVALUATE PREDATION RISK USING CHEMICAL SIGNALS FROM PREDATORS; accepted October 26, 2005) Published Online April 4, 2006 Abstract--Hard clams, Mercenaria mercenaria, are sessile, filter-feeding organisms that are heavily preyed upon by blue crabs, which find their clam prey

Smee, Lee

373

Manufacturing of Board Level Waveguide Bus Using Hard Mold  

E-print Network

Manufacturing of Board Level Waveguide Bus Using Hard Mold Xiaohui Lin1 , Xinyuan Dou1 , Amir fabricated on flexible substrate using nickel hard mold. Optical out-of-plane loss test and high speed data, 4]. In this work, we present a low cost molding method has been applied to fabricate optical

Chen, Ray

374

Cavities and tunnels in hard rock by thermal spallation  

Microsoft Academic Search

Thermal spallation of hard rocks has been used commercially for many years to cut granite in quarries and to produce blast holes in taconite mines. It is an economical process for creating cavities in hard rocks, which are difficult to drill or mine by conventional methods. These cavities have great potential for storage of liquids and gases and for storage

1985-01-01

375

Potential Demand for Apple Hard Cider in Michigan  

Microsoft Academic Search

This paper reports the results of market place and consumer research for hard apple cider. The objectives of the research were to determine potential demand for and constraints to the supply of hard apple cider in Michigan. The research was undertaken using on-site and focus group interviews of managers of microbrews, brew-pubs, restaurants and retailers. The research revealed much enthusiasm

Denise Y. Mainville; H. Christopher Peterson

2005-01-01

376

Viscosity, hard sphere diameter and interionic potential for liquid lead  

E-print Network

L-347 Viscosity, hard sphere diameter and interionic potential for liquid lead G. Chaussemy The Macedo-Litovitz equation for a hard sphere liquid provides a satisfactory model for the viscosity of lead and molecular dynamics. The activation energy for viscosity (0.07 eV) is similar to the height of the interionic

Boyer, Edmond

377

Which hardness (nano or macrohardness) should be evaluated in cavitation?  

Microsoft Academic Search

This paper is concerned with the analysis of data obtained from instrumented depth-sensing nanoindentation testing performed on materials whose hardness varies with depth from surface. The objective is to determine which hardness (nano or macrohardness) should be evaluated in functionally graded materials to correlate the material properties to its performance in cavitation. A linear relationship between H2\\/E and cavitation erosion

C. Godoy; R. D. Mancosu; R. R. Machado; P. J. Modenesi; J. C. Avelar-Batista

2009-01-01

378

Amphiphilic hard body mixtures Matthias Schmidt and Christian von Ferber  

E-print Network

Amphiphilic hard body mixtures Matthias Schmidt and Christian von Ferber Institut fu¨r Theoretische Received 16 June 2001; published 29 October 2001 In order to study ternary amphiphilic mixtures, we and amphiphilic particles, where the hydrophilic head is modeled as a hard sphere and the hydrophobic tail

Ott, Albrecht

379

The European Values Study  

NSDL National Science Digital Library

Curious minds want to know: "What exactly do Europeans believe?" It's an important and interesting question, and the directors and researchers in charge of the European Values Study (EVS) have been looking into this subject since the early 1980s. Based in the Netherlands the EVS concerns itself with asking Europeans about religion and morality, politics, work and leisure, and relationships. On their homepage, visitors can learn about their work and view previous and current surveys. While visitors do not have access to the raw data on the site, they can look at the questionnaires and read publications based on this research.

380

Earned Value-Added  

NASA Technical Reports Server (NTRS)

Earned value management [EVM] ...either you swear by it, or swear at it. Either way, there s no getting around the fact that EVM can be one of the most efficient and insightful methods of synthesizing cost, schedule, and technical status information into a single set of program health metrics. Is there a way of implementing EVM that allows a program to reap its early warning benefits while avoiding the pitfalls that make it infamous to its detractors? That s the question recently faced by the International Space Station [ISS] program.

Jansen, Michael

2005-01-01

381

Editorial: Face Value  

NSDL National Science Digital Library

As instructors of young people, we have come to look beyond unflattering fashions, unfortunate piercings, and unbelievable hair to the people beyond. Misinterpreting a resting face, however, is a more insidious problem because it is essentially automatic and falls in line with what we already do well. We are in a position of remarkable power in our classrooms and laboratories. To a truly stunning degree, our expectations of our students become their reality. Accurately developing those expectations is central to their success. In this month's column, the editor discusses compelling reasons why educators should not evaluate their students based on "face value."

Ann Cutler

2008-09-01

382

Preliminary Financial Feasibility AnalysisPreliminary Financial Feasibility AnalysisPreliminary Financial Feasibility Analysis for a Twofor a Twofor a Two---Acre Hard Clam Culture FarmAcre Hard Clam Culture FarmAcre Hard Clam Culture Farm  

E-print Network

Preliminary Financial Feasibility Analysis for a Twofor a Twofor a Two---Acre Hard Clam Culture FarmAcre Hard Clam Culture FarmAcre Hard Clam Culture Farm in the Southwest Florida Area*in the Southwest Florida Area Smallregarding Smallregarding Small---scale Commercial Culture of Hard Clams in the Cedar Key Area of Florida

Florida, University of

383

Synthesis, Structure, and Properties of Refractory Hard-Metal Borides  

NASA Astrophysics Data System (ADS)

As the limits of what can be achieved with conventional hard compounds, such as tungsten carbide, are nearing reach, super-hard materials are an area of increasing industrial interest. The refractory hard metal borides, such as ReB2 and WB4, offer an increasingly attractive alternative to diamond and cubic boron nitride as a next-generation tool material. In this Thesis, a thorough discussion is made of the progress achieved by our laboratory towards understanding the synthesis, structure, and properties of these extremely hard compounds. Particular emphasis is placed on structural manipulation, solid solution formation, and the unique crystallographic manifestations of what might also be called "super-hard metals".

Lech, Andrew Thomas

384

Hard ticks (Acari, Ixodidae) of Croatia  

PubMed Central

Abstract The present paper is based on original and literature data. In Croatia the first studies on the occurrence of ixodid species were made about 80 years ago. The number of tick species recorded in Croatia considerably increased during the 1950s, 60s, 70s and 80s of the past century. A total of 21 species of hard tick belonging to 5 genera have been recorded in Croatia. Ixodes is the best represented genus, with seven species recorded. Haemaphysalis is represented by six species, followed by Rhipicephalus with four species. Dermacentor and Hyalomma are represented by two species each. The ticks were collected on 47 different host species. Eleven tick species were collected on Bos taurus and Ovis aries, followed by Capra hircus and Equus caballus with 8 species and Canis lupus familiaris with 6 species. On the remaining 42 host species one, two or three tick species were collected. The most widespread tick is Ixodes ricinus which was found on 25 different host species. PMID:23372407

Kr?mar, Stjepan

2012-01-01

385

Dynamics of hard sphere colloidal dispersions  

NASA Technical Reports Server (NTRS)

Our objective is to perform on homogeneous, fully equilibrated dispersions the full set of experiments characterizing the transition from fluid to solid and the properties of the crystalline and glassy solid. These include measurements quantifying the nucleation and growth of crystallites, the structure of the initial fluid and the fully crystalline solid, and Brownian motion of particles within the crystal, and the elasticity of the crystal and the glass. Experiments are being built and tested for ideal microgravity environment. Here we describe the ground based effort, which exploits a fluidized bed to create a homogeneous, steady dispersion for the studies. The differences between the microgravity environment and the fluidized bed is gauged by the Peclet number Pe, which measures the rate of convection/sedimentation relative to Brownian motion. We have designed our experiment to accomplish three types of measurements on hard sphere suspensions in a fluidized bed: the static scattering intensity as a function of angle to determine the structure factor, the temporal autocorrelation function at all scattering angles to probe the dynamics, and the amplitude of the response to an oscillatory forcing to deduce the low frequency viscoelasticity. Thus the scattering instrument and the colloidal dispersion were chosen such as that the important features of each physical property lie within the detectable range for each measurement.

Zhu, J. X.; Chaikin, Paul M.; Phan, S.-E.; Russel, W. B.

1994-01-01

386

Revisiting the phase diagram of hard ellipsoids.  

PubMed

In this work, the well-known Frenkel-Mulder phase diagram of hard ellipsoids of revolution [D. Frenkel and B. M. Mulder, Mol. Phys. 55, 1171 (1985)] is revisited by means of replica exchange Monte Carlo simulations. The method provides good sampling of dense systems and so, solid phases can be accessed without the need of imposing a given structure. At high densities, we found plastic solids and fcc-like crystals for semi-spherical ellipsoids (prolates and oblates), and SM2 structures [P. Pfleiderer and T. Schilling, Phys. Rev. E 75, 020402 (2007)] for x : 1-prolates and 1 : x-oblates with x ? 3. The revised fluid-crystal and isotropic-nematic transitions reasonably agree with those presented in the Frenkel-Mulder diagram. An interesting result is that, for small system sizes (100 particles), we obtained 2:1- and 1.5:1-prolate equations of state without transitions, while some order is developed at large densities. Furthermore, the symmetric oblate cases are also reluctant to form ordered phases. PMID:22482570

Odriozola, Gerardo

2012-04-01

387

The Hard X ray Telescope Mission  

NASA Technical Reports Server (NTRS)

The Hard X Ray Telescope (HXT) 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 and much better angular resolution in the 10100 keV band, and (3) higher sensitivity for detecting gamma ray lines of known energy in the 100 keV to 1 MeV band. The institutions collaborating in the study are: Smithsonian Astrophysical Observatory, Marshall Space Flight Center, Naval Research Laboratory, Goddard Space Flight Center, Argonne National Laboratory, Danish Space Research Institute, Osservatorio Astronomica di Brera (Merate), and Centre d'Etudes Spatiale des Rayonnements (Toulouse). The instrumentation includes several grazing incidence double conical telescopes with multilayer coatings that focus up to 100 keV and a single Laue crystal telescope that functions to 1 MeV. The detectors are CCDs, and germanium, and/or CdZnTe position sensitive arrays.

Gorenstein, Paul

1997-01-01

388

Hardness Testing at Multiple Length Scales  

NSDL National Science Digital Library

University of Maryland, Department of Materials Science and Engineering (MSE) Lab Coordinator Robert Bonenberger, Ph.D., MSE Professor and Chair Robert M. Briber, Department of Mechanical Engineering (ME) Associate Professor Hugh Bruck, Jaime Cardena-Garcia, Ph.D., and MSE Associate Professor Luz Martinez-Miranda recently completed work on an NSF-funded project titled Development of Educational Materials and Acquisition of Equipment for a Nanoscale to Microscale Engineering Laboratory. The project, supported by the NSF's Course, Curriculum and Laboratory Improvement (CCLI) program, was used to develop new laboratory experiments that effectively engage undergraduate engineering students in the scientific processes and exploration of concepts in nanotechnology. Work funded under the proposal also helped integrate significant advances in nanotechnology research with the undergraduate engineering laboratory curriculum through the development of a new teaching lab. Two significant experimental systems were assembled to give students an enhanced laboratory experience: a pair of micro-tensile testers, used for determining the mechanical properties of micron-scale devices and materials; and an integrated nanoindentation/scanning probe microscope (SPM) testing system, used for measuring the hardness and elasticity of materials at the nanoscale, and for imaging samples. Bruck's junior-level ENME 382: Engineering Materials and Manufacturing Processes class was one of those that benefited from the new equipment and curriculum. This is one example of lab modules created for it as part of the overall project.

Martinez-Miranda, Luz

2009-11-27

389

Computational Modeling Develops Ultra-Hard Steel  

NASA Technical Reports Server (NTRS)

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

2007-01-01

390

Hard Spheres: Crystallization and Glass Formation  

E-print Network

Motivated by old experiments on colloidal suspensions, we report molecular dynamics simulations of assemblies of hard spheres, addressing crystallization and glass formation. The simulations cover wide ranges of polydispersity s (standard deviation of the particle size distribution divided by its mean) and particle concentration. No crystallization is observed for s > 0.07. For 0.02 stabilise the fluid but to destabilise the crystal. At a given polydispersity (< 0.07) we find three regimes of nucleation: standard nucleation and growth at concentrations in and slightly above the coexistence region; "spinodal nucleation", where the free energy barrier to nucleation appears to be negligible, at intermediate concentrations; and, at the highest concentrations, a new mechanism, still to be fully understood, which only requires small re-arrangement of the particle positions. The cross-over between the second and third regimes occurs at a concentration, around 58% by volume, where the colloid experiments show a marked change in the nature of the crystals formed and the particle dynamics indicate an "ideal" glass transition.

P. N. Pusey; E. Zaccarelli; C. Valeriani; E. Sanz; W. C. K. Poon; M. E. Cates

2009-08-12

391

World Values Survey  

NSDL National Science Digital Library

Started in 1981, the World Values Survey is an ambitious worldwide investigation of sociocultural and political change being conducted by an international network of social scientists at universities across the globe. Since its inception, a total of four waves of representative sample research have been conducted producing "evidence of gradual but pervasive changes in what people want out of life." The survey shows that the basic direction of these changes is, to some extent, predictable. Following from this intriguing (and perhaps contestable) thesis, the website provides access to a number of the publications that have been generated from the group's scholarship, along with information about ordering various monographs and other publications. Visitors can also view the various questionnaires used to sample the different population groups, and read news updates about their work. As mentioned, the site also allows visitors to download some of the most recent work done by the scholars at the World Values Survey, including papers dealing with democratic aspirations and ideals in East Asia and postmaterialism.

392

Assessing spatial trends of cultural stone weathering intensity using a hardness tester: The case of Manglieu Saint-Sébastien church (France)  

NASA Astrophysics Data System (ADS)

In heritage science, the quantitative assessment of rock hardness is of primary interest to characterize the degree of weathering of a cultural stone. Modern hardness testers are non-destructive and can be used on cultural heritage materials to collect repeated measurements of rock strength without causing damage. Furthermore, the development of portable solutions such as the Equotip Piccolo 2 facilitates the in situ hardness survey of a whole façade of a monument. It allows to address the question of spatial variability of weathering intensity within a monument, and the mapping of hardness values can reveal strong gradients or discontinuities in stone decay induced by restoration operations. The present study deals with the spatial distribution of stone hardness on the façade of the Saint-Sébastien Romanesque abbey church at Manglieu, in the French Massif Central. It was built during the twelfth century and listed as a protected historic monument in 1840. During the Late 19th century, the lower part of the west-facing wall was restored and the original gneissic material was replaced by granitic ashlars. Since this operation, an intense deterioration has affected the original gneissic stones overlying the granitic base of the wall. Our objective is to quantitatively assess the effect of this restoration on the current spatial trends of the gneiss hardness. Rock strength values were collected using the portable hardness tester Equotip Piccolo 2, and the spatial distribution was investigated at two scales: (i) At the portal scale, the hardness values of all stones were measured based on 30 values per stone; (ii) At the stone scale, a systematic sampling method was performed on two gneissic ashlars in order to collect hardness values over a grid of 9 cm resolution. On each sample, the repeated impact method was performed: 20 consecutive measurements at the same location were collected in order to reconstruct the spatial variation of weathering degree within the stone surface. At the portal scale, the results indicate an inverse correlation between the weathering intensity of gneissic stones and the vertical distance to the granitic ashlars, suggesting the deleterious effects of the water capillary rise enhanced by the incorporation of low porosity granite at the base of the wall. At the stone scale, the weathering maps display a strong spatial autocorrelation of hardness values, suggesting a gradual diffusive process of weathering within the stones.

Roussel, Erwan; Gruson, Soizic; Vautier, Franck; Voldoire, Olivier; André, Marie-Françoise

2014-05-01

393

Metric analysis of the hard palate in children with Down syndrome: a comparative study.  

PubMed

The hard palate is viewed as playing an important role in the passive articulation of speech. Its probable role in the defective articulation of speech in individuals with Down syndrome has been examined in the present study. In individuals with Down syndrome, the hard palate is highly arched, constricted, and narrow and stair type with malformed misaligned teeth and a large and fissured tongue. As a result good palato-lingual contact is not achieved, with resulting defective articulation. Using orthodontic and prosthodontic principles could modify this situation, i.e. the anatomy of the hard palate. The altered palatal contour may give better placing to the tongue, leading to improved palato-lingual contact and articulation. The dimensional parameters measured were: average linear width (AVL), average curvilinear width (AVCL), average height (AVH) at different planes; average antero-posterior length (AAP), average volume (V), palatal arch length (PAL), and palatal index (PI). The findings were compared with those of controls of the same age and sex. The AVL, AVCL, AAP, PAL, V and PI values of patients with Down syndrome were found to be less than the corresponding values of controls and the average height values of patients with Down syndrome were greater than the corresponding values of controls. Statistical significance was observed in all measurements between the controls and the patients with Down syndrome, especially in those concerning the height and the volume of the oral cavity. Observations from this study have suggested that prostheses might be designed to modify the palatal anatomy and produce better articulation in people with Down syndrome. PMID:17692189

Bhagyalakshmi, Gopalan; Renukarya, Annappa Jai; Rajangam, Sayee

2007-07-01

394

Hardness, Microstructure, and Residual Stresses in Low Carbon Steel Welding with Post-weld Heat Treatment and Temper Bead Welding  

NASA Astrophysics Data System (ADS)

This paper investigates the effects of post-weld heat treatment (PWHT) and temper bead welding (TBW) on hardness, microstructure and residual stresses in multi-layer welding on low carbon steel specimens made with two different weld geometries, viz. (1) smooth-contoured and (2) U-shaped. It was found that the PWHT technique gave overall lower hardness than the TBW technique, but the hardness values in both techniques were acceptable. Microscopy analysis showed that the TBW technique was more effective in tempering the heat affected zone as the grain size decreased slightly at the fusion line in spite of the higher temperature at the fusion line. Residual stresses measured using the hole-drilling method showed that the residual stress is not reduced below yield stress near the last bead solidified in TBW. Only PWHT gives low residual stress results in this area. High tensile residual stresses may result in sensitivity to fatigue loading.

Aloraier, Abdulkareem S.; Joshi, Suraj; Price, John W. H.; Alawadhi, Khaled

2014-04-01

395

Spectral evolution of gamma-ray bursts detected by the SIGNE experiment. 1: Correlation between intensity and spectral hardness  

NASA Astrophysics Data System (ADS)

We study the continuum spectral evolution of 16 gamma-ray bursts detected by the Franco-Soviet SIGNE experiment in 1981-1982 by fitting time resolved (0.5 s) spectra in count space with simple thermal bremsstrahlung and synchrotron models. We find that there is no single characteristic of spectral evolution: we see hard-to-soft, soft-to-hard, luminosity-hardness tracking, and chaotic evolution. We perform correlation studies between instantaneous burst intensity and spectral temperature for seven bursts. While we basically confirm the existence of a correlation between these variables as originally claimed by Golenetskii et al. (1983) we find higher values and a broader range of correlation indices.

Kargatis, Vincent E.; Liang, Edison P.; Hurley, Kevin C.; Barat, C.; Eveno, E.; Niel, M.

1994-02-01

396

Taxonomy, Anatomy, and Biology of theTaxonomy, Anatomy, and Biology of the Hard ClamHard Clam  

E-print Network

Taxonomy, Anatomy, and Biology of theTaxonomy, Anatomy, and Biology of the Hard ClamHard Clam Shellfish Aquaculture Extension Program Cedar Key, FLy, LNST@ufl.edu #12;TaxonomyTaxonomy Kingdom: Animalia in sediment #12;Clam Taxonomy Subclass Heterodonta ­ clam-like with large hinge teeth Order Veneroidae

Florida, University of

397

Evaluation of Light Curing Distance and Mylar Strips Color on Surface Hardness of Two Different Dental Composite Resins  

PubMed Central

Introduction: Hardness is one of the basic properties of dental materials, specially composite resins which is relevant to their polymerization. The aim of this study was to evaluate the effect of light curing distance and the color of clear Mylar strips on surface hardness of Silorane-based (SCR) and Methacrylate-based composite resins (MCR). Materials and methods: 40 samples of MCRs (Filtek Z250) and SCRs (Filtek P90) were prepared in size of 5 mm×2 mm (80 samples in total). The samples divided into 8 groups (10 samples in each one) based on the color of clear Mylar strips (white or blue) and distance from light curing source (0 mm or 2 mm). All the samples cured for 40 second and stored in incubator for 24 hours in 37°C temperature. Surface hardness test was done by Vickers test machine and the collected data were analyzed by one-way ANOVA and paired T-test by using SPSS software version 13 at significant level of 0.05. Results: MCRs cured with blue Mylar strips from 0 mm distance had the highest (114.5 kg/mm2) and SCRs cured with white Mylar strips from 2 mm distance had the lowest (42.2 kg/mm2) mean of surface hardness. Also, the results of comparison among SCRs and MCRs showed significant differences among all groups (all P values <0.01). Conclusion: The hardness decreased as the distance increased and the blue Mylar strips provided higher hardness than clear ones. Also, Filtek Z250 showed higher hardness compared to Filtek P90. PMID:25228939

Mousavinasab, Seyed Mostafa; Barekatain, Mehrdad; Sadeghi, Elahe; Nourbakhshian, Farzaneh; Davoudi, Amin

2014-01-01

398

Engineering Technology: Value Engineer  

NSDL National Science Digital Library

In this video adapted from Pathways to Technology, youâÂÂll learn about the career opportunities available with a degree in engineering. Gina Ferrera, the community college graduate featured in this video, is a value engineer, and her work on night-vision goggles helps people see in the dark. Gina is responsible for improving her company's products, while improving quality and reducing costs. She explains why she went to college, decided to study engineering, and then work in telecommunications. Also, Gina talks about why she enjoys her job and her chosen field. The video runs 3:03 and is accompanied by a background essay, standards alignment, and discussion questions. Users who sign up for a free account can save the resource and download the video as well.

2012-05-24

399

77 FR 34073 - Value Engineering  

Federal Register 2010, 2011, 2012, 2013

...of Federal Procurement Policy Value Engineering AGENCY: Office of Federal Procurement...Budget Circular No. A-131, ``Value Engineering...revise OMB Circular A- 131, Value Engineering, to update and reinforce policies...

2012-06-08

400

Converting hard copy documents for electronic dissemination  

SciTech Connect

Since the advent of computer systems, the goal of a paperless office, and even a paperless society, has been pursued. While the normal paper flow in an organization is far from totally automated, particularly for items requiring signatures or authorizations, electronic information dissemination is becoming an almost simple task. The reasons for providing on-line documents are many and include faster and easier access for everyone, elimination of printing costs, reduction of wasted shelf and desk space, and the security of having a centrally-located, always up-to-date document. New computer software even provides the user with the ability to annotate documents and to have bookmarks so that the old scribbled-in and dog-eared manual can be replaced without loosing this `customizability`. Moreover, new hypermedia capabilities mean that documents can be read in a non-linear fashion and can include color figures and photographs, audio, and even animation sequences, capabilities which exceed those of paper. The proliferation of network-based information servers, coupled with the growth of the Internet, has enticed academic, governmental, and even commercial organizations to provide increasing numbers of documents and data bases in electronic form via the network, not just to internal staff, but to the public as well. Much of this information, which includes everything from mundane company procedures to spiffy marketing brochures, was previously published only in hard copy. Converting existing documents to electronic form and producing only electronic versions of new documents poses some interesting challenges to the maintainer or author.

Hoffman, F.

1994-12-31

401

High efficiency, radiation-hard solar cells  

SciTech Connect

The direct gap of the In{sub 1-x}Ga{sub x}N alloy system extends continuously from InN (0.7 eV, in the near IR) to GaN (3.4 eV, in the mid-ultraviolet). This opens the intriguing possibility of using this single ternary alloy system in single or multi-junction (MJ) solar cells of the type used for space-based surveillance satellites. To evaluate the suitability of In{sub 1-x}Ga{sub x}N as a material for space applications, high quality thin films were grown with molecular beam epitaxy and extensive damage testing with electron, proton, and alpha particle radiation was performed. Using the room temperature photoluminescence intensity as a indirect measure of minority carrier lifetime, it is shown that In{sub 1-x}Ga{sub x}N retains its optoelectronic properties at radiation damage doses at least 2 orders of magnitude higher than the damage thresholds of the materials (GaAs and GaInP) currently used in high efficiency MJ cells. This indicates that the In{sub 1-x}Ga{sub x}N is well-suited for the future development of ultra radiation-hard optoelectronics. Critical issues affecting development of solar cells using this material system were addressed. The presence of an electron-rich surface layer in InN and In{sub 1-x}Ga{sub x}N (0 < x < 0.63) was investigated; it was shown that this is a less significant effect at large x. Evidence of p-type activity below the surface in Mg-doped InN was obtained; this is a significant step toward achieving photovoltaic action and, ultimately, a solar cell using this material.

Ager III, J.W.; Walukiewicz, W.

2004-10-22

402

Surface modulation of dental hard tissues  

NASA Astrophysics Data System (ADS)

Tooth surfaces play a central role in the equilibrium of dental hard tissues, in which contrasting processes lead to loss or deposition of materials. The central interest of this Thesis was the modulation of tooth surfaces to control such equilibrium. Four specific studies were carried out to investigate different classes of surface modulating agents. These are: (1) Ionic modulation of the enamel surface to enhance stain removal . Dental stain is the most apparent form of tooth surface deposit. The nature of extrinsic stain in terms of spatial chemical composition was studied by using electron probe microanalysis. An ionic surface modulating agent, sodium tripolyphosphate (STPP), was evaluated. Image analysis methodologies were developed and the ability of STPP in stain removal was proved. (2) Thin film modulation with substantive polymeric coating and the effect on in vitro enamel de/re-mineralization . A novel polymeric coating that formed a thin film on the tooth surface was investigated for its inhibitory effect on artificial enamel caries, without interfering with the remineralization process. The preventive effect was distinct, but the mineral redeposition was questionable. (3) Thick film modulation with fluoride containing sealants and the effect on in vitro enamel and root caries development. Fluoride incorporated into resin material is an example of combining different classes of surface modulating agents to achieve an optimal outcome. A proper combination, such as in resin modified glass ionomer, showed in vitro caries inhibitory effect beyond the material boundary in both enamel and dentin. (4) Thick film modulation with dental adhesives and the determination of adhesion to dentin. Dentin adhesives modulate intracoronal tooth surfaces by enhancing adhesion to restorative materials. Conventional nominal bond tests were inadequate to determine the performance of current high strength adhesives. It was shown that interfacial fracture toughness test was more appropriate. In general, this Thesis evaluates diverse tooth surface modulations, for which several experimental methodologies had to be developed. These will be invaluable for the development of succeeding generations of surface modulating agents.

Tantbirojn, Daranee

403

Reliability of hard plastic clad silica fibers  

NASA Astrophysics Data System (ADS)

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

Skutnik, Bolesh J.; Spaniol, Stefan

2006-04-01

404

Hard X-ray Timing with EXIST  

E-print Network

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 from SGRs could be detected out to the Virgo cluster. The large duty cycle and all sky monitor nature of the mission will enable QPOs from luminous AGN and BH X-ray binaries to be studied on timescales not possible before. I provide an overview of the mission concept and Reference Design, the X-ray timing science prospects for EXIST, and how these might be further optimized in the current Study for EXIST as the BHFP so that EXIST might include many of the desirable features of a next-generation timing mission.

Jonathan E. Grindlay

2004-03-23

405

Guided waves for monitoring heat treatment duration and material hardness  

NASA Astrophysics Data System (ADS)

Elastic properties of materials can be easily determined from the ultrasonic wave velocity measurement. However, material hardness cannot be obtained from the ultrasonic wave speed. Heat treatment and aging affect the microstructure of materials changing their hardness and strength. In this study it is investigated how the attenuation of ultrasonic guided waves is affected by the duration of heat treatment and varying material hardness. To this aim six identical Aluminum 2024 alloy plate specimens were subjected to different durations of heat treatment at 150°C and were inspected nondestructively propagating Lamb waves through the specimens. Attenuation of the Lamb wave was found to be inversely related to the hardness. Rockwell Hardness test was performed to corroborate the ultrasonic observations. In comparison to Rockwell hardness test the ultrasonic inspection was found to be more sensitive to the heat treatment duration. From these results it is concluded that guided wave inspection method is a reliable and probably more desirable alternative for characterizing the hardness of heat treated materials.

Korde, Nilesh; Kundu, Tribikram

2012-04-01

406

Nucleation-Mode Localization in Hard-Soft Nanocomposites  

NASA Astrophysics Data System (ADS)

Aligned hard-soft nanocomposites continue to be an active research area in permanent magnetism, challenged by demanding processing requirements but also encouraged by experimental proofs of principle. The approach was initially outlined by Kneller and Hawig (1991), who advocated hard-soft multilayers. Skomski and Coey (1993) considered three-dimensional nanostructures, such as soft spheres in a hard matrix, and predicted an upper energy-product limit of about 1000 kJ/m^3. It is well-established that the dimensions of the soft regions cannot be larger than twice the domain-wall width of the hard phase, but otherwise it was believed that geometry has a rather secondary effect. However, our recent research reveals substantial differences. Soft-in-hard geometries are better than hard-in-soft geometries and embedded soft spheres are better than multilayers. This is in close analogy to the dimensionality-dependent quantum-mechanical delocalization of electrons in an inhomogeneous potential and to the behavior of impurity states in the band gaps of solids. Transparent analytical nucleation-field solutions are found for some geometries and in the limit of very small soft inclusion as a function of the hard-phase coercivity and hysteresis-loop shape.

Skomski, Ralph; Balasubramanian, Balamurugan; Das, Bhaskar; Sellmyer, D. J.

2013-03-01

407

Hard Photodisintegration of Proton Pairs in 3He  

NASA Astrophysics Data System (ADS)

Hard deuteron photodisintegration has been investigated for 20 years, as its cross section follows the constituent counting rule and it provides insight into the interplay between hadronic and quark-gluon degrees of freedom in high-momentum transfer exclusive reactions. We have now measured for the first time hard pp-pair disintegration in the reaction ? 3He?pp+n, using kinematics corresponding to a spectator neutron. Cross sections were measured for 90° c.m. at 8 beam energies, from 0.8 to 4.7 GeV. Preliminary results will be presented and compared to the hard deuteron photodisintegration data.

Piasetzky, Eli; Pomerantz, Ishay; Higinbotham, D.; Strauch, S.; Gilman, R.

2008-10-01

408

Self-diffusion in liquid gallium and hard sphere model  

NASA Astrophysics Data System (ADS)

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.

Blagoveshchenskii, Nikolay; Novikov, Arkady; Puchkov, Alexander; Savostin, Vadim; Sobolev, Oleg

2015-01-01

409

Effect of Rolling and Annealing on Hardness of Brass  

NSDL National Science Digital Library

This lesson plan will provide an introduction to the hardness of materials. Specifically, the exercise will allow students the opportunity to "observe the changes in hardness of brass resulting from different percentages of rolling, along with the accompanying changes in microstructure." Students will also learn the differences between the hardness and strength of a material. The module would be best for upper level high school and college students, and should take one class period to complete. The document is available to download in PDF file format.

Cantrell, Andrew

2012-10-26

410

Effects of cold rolling deformation on microstructure, hardness, and creep behavior of high nitrogen austenitic stainless steel  

NASA Astrophysics Data System (ADS)

Effects of cold rolling deformation on the microstructure, hardness, and creep behavior of high nitrogen austenitic stainless steel (HNASS) are investigated. Microstructure characterization shows that 70% cold rolling deformation results in significant refinement of the microstructure of this steel, with its average twin thickness reducing from 6.4 ?m to 14 nm. Nanoindentation tests at different strain rates demonstrate that the hardness of the steel with nano-scale twins (nt-HNASS) is about 2 times as high as that of steel with micro-scale twins (mt-HNASS). The hardness of nt-HNASS exhibits a pronounced strain rate dependence with a strain rate sensitivity (m value) of 0.0319, which is far higher than that of mt-HNASS (m = 0.0029). nt-HNASS shows more significant load plateaus and a higher creep rate than mt-HNASS. Analysis reveals that higher hardness and larger m value of nt-HNASS arise from stronger strain hardening role, which is caused by the higher storage rate of dislocations and the interactions between dislocations and high density twins. The more significant load plateaus and higher creep rates of nt-HNASS are due to the rapid relaxation of the dislocation structures generated during loading.

Sun, Shi-Cheng; Sun, Gui-Xun; Jiang, Zhong-Hao; Ji, Chang-Tao; Liu, Jia-An; Lian, Jian-She

2014-02-01

411

Comparison of Hard Surface and Soft Soil Impact Performance of a Crashworthy Composite Fuselage Concept  

NASA Technical Reports Server (NTRS)

A comparison of the soft soil and hard surface impact performance of a crashworthy composite fuselage concept has been performed. Specifically, comparisons of the peak acceleration values, pulse duration, and onset rate at specific locations on the fuselage were evaluated. In a prior research program, the composite fuselage section was impacted at 25 feet per second onto concrete at the Impact Dynamics Research Facility (IDRF) at NASA Langley Research Center. A soft soil test was conducted at the same impact velocity as a part of the NRTC/RITA Crashworthy and Energy Absorbing Structures project. In addition to comparisons of soft soil and hard surface test results, an MSC. Dytran dynamic finite element model was developed to evaluate the test analysis correlation. In addition, modeling parameters and techniques affecting test analysis correlation are discussed. Once correlated, the analytical methodology will be used in follow-on work to evaluate the specific energy absorption of various subfloor concepts for improved crash protection during hard surface and soft soil impacts.

Sareen, Ashish K.; Sparks, Chad; Mullins, B. R., Jr.; Fasanella, Edwin; Jackson, Karen

2002-01-01

412

Sharp tip geometry and its effect on hardness in nanoindentation experiments  

NASA Astrophysics Data System (ADS)

In this article, we used an indenter, sharper than a Berkovich indenter, consisting of a triangular pyramid with a face angle of 80deg, and compared the difference between our own and the Berkovich indenters. First, the cross-sectional shapes of the indenters were analyzed by the Shih, Yang, and Li model [C. W. Shih, M. Yang, and J. C. M. Li, J. Mater. Res. 6, 2623 (1991)]. The result suggested that our sharp indenter has more deviation from the ideal triangular pyramid than the Berkovich indenter, resulting from the difference in sharpness of the indenters. Second, we determined an area function for our indenter using fused silica and compared it with those of an ideal triangular pyramid and a Berkovich indenter. There was a larger difference between the real and ideal indenters in our indenter than in the Berkovich case. Third, hardness measurements indicated that hardness increases with increases in depth and reaches a constant value in both cases of fused silica and single-crystal Si. This dependence of hardness on depth is explained herein in a qualitative manner.

Ikezawa, Kazuhiro; Maruyama, Tadashi

2002-06-01

413

Orientational ordering in hard rectangles: The role of three-body correlations.  

PubMed

We investigate the effect of three-body correlations on the phase behavior of hard rectangle two-dimensional fluids. The third virial coefficient B3 is incorporated via an equation of state that recovers scaled particle theory for parallel hard rectangles. This coefficient, a functional of the orientational distribution function, is calculated by Monte Carlo integration, using an accurate parametrized distribution function, for various particle aspect ratios in the range of 1-25. A bifurcation analysis of the free energy calculated from the obtained equation of state is applied to find the isotropic (I)-uniaxial nematic (N(u)) and isotropic-tetratic nematic (N(t)) spinodals and to study the order of these phase transitions. We find that the relative stability of the N(t) phase with respect to the isotropic phase is enhanced by the introduction of B3. Finally, we have calculated the complete phase diagram using a variational procedure and compared the results with those obtained from scaled particle theory and with Monte Carlo simulations carried out for hard rectangles with various aspect ratios. The predictions of our proposed equation of state as regards the transition densities between the isotropic and orientationally ordered phases for small aspect ratios are in fair agreement with simulations. Also, the critical aspect ratio below which the N(t) phase becomes stable is predicted to increase due to three-body correlations, although the corresponding value is underestimated with respect to simulation. PMID:16863310

Martínez-Ratón, Yuri; Velasco, Enrique; Mederos, Luis

2006-07-01

414

Novel microwave assisted chemical synthesis of Nd2Fe14B hard magnetic nanoparticles  

NASA Astrophysics Data System (ADS)

The high coercivity and excellent energy product of Nd2Fe14B hard magnets have led to a large number of high value added industrial applications. Chemical synthesis of Nd2Fe14B nanoparticles is challenging due to the large reduction potential of Nd3+ and the high tendency for Nd2Fe14B oxidation. We report the novel synthesis of Nd2Fe14B nanoparticles by a microwave assisted combustion process. The process consisted of Nd-Fe-B mixed oxide preparation by microwave assisted combustion, followed by the reduction of the mixed oxide by CaH2. This combustion process is fast, energy efficient and offers facile elemental substitution. The coercivity of the resulting powders was ~8.0 kOe and the saturation magnetization was ~40 emu g-1. After removal of CaO by washing, saturation magnetization increased and an energy product of 3.57 MGOe was obtained. A range of magnetic properties was obtained by varying the microwave power, reduction temperature and Nd to Fe ratio. A transition from soft to exchange coupled to hard magnetic properties was obtained by varying the composition of NdxFe1-xB8 (x varies from 7% to 40%). This synthesis procedure offers an inexpensive and facile platform to produce exchange coupled hard magnets.

Swaminathan, Viswanathan; Deheri, Pratap Kumar; Bhame, Shekhar Dnyaneswar; Ramanujan, Raju Vijayaraghavan

2013-03-01

415

Manufacture, microstructure and mechanical properties of Wsbnd Tasbnd N nano-structured hard films  

NASA Astrophysics Data System (ADS)

W1-xTaxNy (x = 0-0.95) hard films were deposited on Si substrates using reactive direct current magnetron sputtering. The effect of tantalum concentration on phase composition, microstructure, surface morphology, adhesion strength, and hardness of the films has been studied by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy, nano-indenter, and scratch tester. It was found that regardless of tantalum concentration all the W1-xTaxNy films show face centered cubic structure, and form Wsbnd Tasbnd N solid solution. The hardness and Youngs' modulus of W1-xTaxNy films initially increase and then decrease with increasing tantalum concentration, after passing the maximum value of 38 GPa and 360 GPa at x = 0.31, respectively. The adhesion strength of coating to silicon substrate is in the range of 27-35 N, no obvious variation trend of adhesion strength with tantalum concentration was observed.

Yang, J. F.; Jiang, Y.; Yuan, Z. G.; Wang, X. P.; Fang, Q. F.

2012-08-01

416

Discrete perturbation theory for the hard-core attractive and repulsive Yukawa potentials  

NASA Astrophysics Data System (ADS)

In this work we apply the discrete perturbation theory [A. L. Benavides and A. Gil-Villegas, Mol. Phys. 97, 1225 (1999)] to obtain an equation of state for the case of two continuous potentials: the hard-core attractive Yukawa potential and the hard-core repulsive Yukawa potential. The main advantage of the presented equation of state is that it is an explicit analytical expression in the parameters that characterize the intermolecular interactions. With a suitable choice of their inverse screening length parameter one can model the behavior of different systems. This feature allows us to make a systematic study of the effect of the variation in the parameters on the thermodynamic properties of this system. We analyze single phase properties at different conditions of density and temperature, and vapor-liquid phase diagrams for several values of the reduced inverse screening length parameter within the interval ??=0.1-5.0. The theoretical predictions are compared with available and new Monte Carlo simulation data. Good agreement is found for most of the cases and better predictions are found for the long-range ones. The Yukawa potential is an example of a family of hard-core plus a tail (attractive or repulsive) function that asymptotically goes to zero as the separations between particles increase. We would expect that similar results could be found for other potentials with these characteristics.

Torres-Arenas, J.; Cervantes, L. A.; Benavides, A. L.; Chapela, G. A.; del Río, F.

2010-01-01

417

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

Federal Register 2010, 2011, 2012, 2013

...Technologies, Inc., Coporate Headquaters/Hard Drive Development Division, Lake Forest...Technologies, Inc., Corporate Headquarters/Hard Drive Development Division, Lake Forest...development) services in support of hard drive (also known as disk drive)...

2011-02-24

418

76 FR 70644 - Special Local Regulations; Seminole Hard Rock Winterfest Boat Parade, New River and Intracoastal...  

Federal Register 2010, 2011, 2012, 2013

...1625-AA08 Special Local Regulations; Seminole Hard Rock Winterfest Boat Parade, New River...Lauderdale, Florida during the Seminole Hard Rock Winterfest Boat Parade on Saturday...necessary information about the Seminole Hard Rock Winterfest Boat Parade with...

2011-11-15

419

Heat treatment optimization in the manufacture of Wilson Rockwell steel hardness test blocks  

E-print Network

The heat-treatment process in the manufacture of Wilson Rockwell steel hardness test blocks often produces parts which are inconsistent in the mean hardness and hardness uniformity. In this thesis, the sources of variation ...

Tan, Vincent Tandean

2009-01-01

420

Philosophies, Practices and American Values.  

ERIC Educational Resources Information Center

Three clusters of values are presented. Although not an inclusive description of U.S. values, they do capture significant influences. Second, using these clusters as a backdrop, four current philosophies categorized by Elias and Merriam are discussed, two that are not mainstream values and two that reflect American values. (Author)

Podeschi, Ronald L.

1986-01-01

421

An Introduction to Value Analysis.  

ERIC Educational Resources Information Center

Emphasizes consciousness as a quality which differentiates a human being from other living organisms. Excerpts various perspectives that are value-analyzed to illustrate two assumptions: (1) thinking leads to valuing and values and (2) all psychological perspectives are based upon some value system which can be identified. (JAC)

Takacs, Kalman

1983-01-01

422

Drag and diffusion co-efficients of heavy quarks in hard thermal loop approximations  

E-print Network

The drag and diffusion coefficients of heavy quarks propagating through quark gluon plasma (QGP) have been evaluated using Hard Thermal Loop (HTL) approximations. The HTL corrections to the relevant propagators and vertices have been considered. It is observed that the magnitudes of both the transport coefficients are changed significantly from values obtained by earlier approaches where either (i) the $t$ channel divergence in T=0 pQCD matrix element is shielded simply by Debye mass. or (ii) only HTL resummed propagator is used ignoring the HTL corrections at the interaction vertices. The implications of these changes in the transport coefficients on the heavy ion phenomenology have been discussed.

Surasree Mazumder; Trambak Bhattacharyya; Jan-e Alam

2013-01-24

423

In vitro thermal diffusivity measurements as aging process study in human tooth hard tissues  

NASA Astrophysics Data System (ADS)

In the present work, the Open Photoacoustic Cell Technique was used to find effective thermal diffusivity of human tooth hard tissues, a thermal variable of great interest in the biological science, and inorganic materials. The aging process of the tooth enamel and dentin was analyzed through its effective thermal diffusivity. The study in vitro of these samples showed an increase and posterior decrease with aging of the samples. The values found for the enamel and dentin samples, varied from (36-55)×10-4 cm2 s-1 and (20-32)×10-4 cm2 s-1, respectively.

Carvalho, A. P. N.; Dias, D. T.; Bedeschi, V. C.; Nakamura, O.; Oliveira, M. Q.

2013-11-01

424

Simulation of a hard-spherocylinder liquid crystal with the pe  

NASA Astrophysics Data System (ADS)

The pe physics engine is validated through the simulation of a liquid crystal model system consisting of hard spherocylinders. For this purpose we evaluate several characteristic parameters of this system, namely the nematic order parameter, the pressure, and the Frank elastic constants. We compare these to the values reported in literature and find a very good agreement, which demonstrates that the pe physics engine can accurately treat such densely packed particle systems. Simultaneously we are able to examine the influence of finite size effects, especially on the evaluation of the Frank elastic constants, as we are far less restricted in system size than earlier simulations.

Fischermeier, Ellen; Bartuschat, Dominik; Preclik, Tobias; Marechal, Matthieu; Mecke, Klaus

2014-12-01

425

Debris-bed friction of hard-bedded glaciers  

USGS Publications Warehouse

[1] Field measurements of debris-bed friction on a smooth rock tablet at the bed of Engabreen, a hard-bedded, temperate glacier in northern Norway, indicated that basal ice containing 10% debris by volume exerted local shear traction of up to 500 kPa. The corresponding bulk friction coefficient between the dirty basal ice and the tablet was between 0.05 and 0.08. A model of friction in which nonrotating spherical rock particles are held in frictional contact with the bed by bed-normal ice flow can account for these measurements if the power law exponent for ice flowing past large clasts is 1. A small exponent (n < 2) is likely because stresses in ice are small and flow is transient. Numerical calculations of the bed-normal drag force on a sphere in contact with a flat bed using n = 1 show that this force can reach values several hundred times that on a sphere isolated from the bed, thus drastically increasing frictional resistance. Various estimates of basal friction are obtained from this model. For example, the shear traction at the bed of a glacier sliding at 20 m a-1 with a geothermally induced melt rate of 0.006 m a-1 and an effective pressure of 300 kPa can exceed 100 kPa. Debris-bed friction can therefore be a major component of sliding resistance, contradicting the common assumption that debris-bed friction is negligible. Copyright 2005 by the American Geophysical Union.

Cohen, D.; Iverson, N.R.; Hooyer, T.S.; Fischer, U.H.; Jackson, M.; Moore, P.L.

2005-01-01

426

USE OF FUME SUPPRESSANTS IN HARD CHROMIUM BATHS - EMISSION TESTING  

EPA Science Inventory

The EPA Common Sense Initiative (CSI) is a cooperative effort of government, industry, environmental, and other stakeholder groups to find "cleaner, cheaper, smarter" approaches to environmental management in industrial sectors. The purpose of the project is to assist hard chrome...

427

USE OF FUME SUPPRESSANTS IN HARD CHROMIUM BATHS - QUALITY TESTING  

EPA Science Inventory

The EPA Common Sense Initiative (CSI) is a cooperative effort of government, industry, environmental and other stakeholder groups to find "cleaner, cheaper, smarter" approaches to environmental management in industrial sectors. The purpose of the project is to help hard chromium ...

428

Chemical bonding in hard boron-nitride multilayers  

SciTech Connect

The oxides and nitrides of boron show great potential for use as hard, wear resistant materials. However, large intrinsic stresses and poor adhesion often accompany the hard coatings as found for the cubic boron-nitride phase. These effects may be moderated for use of a layered structure. Alternate stiff layers of boron and compliant layers of nitride are formed by modulating the sputter gas composition during deposition of boron target. The B/BN thin films are characterized with transmission electronic microscope to evaluate the microstructure, nanoindentation to measure hardness and ex-ray absorption spectroscopy to determine chemical bonding. The effects of layer pair spacing on chemical bonding and hardness are evaluated for the B/BN films.

Jankowski, A.F.; Hayes, J.P.

1997-06-01

429

Low voltage vertical recording preamplifier for hard disk drives  

E-print Network

Higher data rate hard disk drives(HDD) and improved read channel electronics are demanding preampli?er performance be extended well beyond 1 Gb/s. Historically, preampli?er power requirements were of low priority; however...

Mellachervu, Ramachandra Murthy

2004-11-15

430

CAPSULE REPORT: HARD CHROME FUME SUPPRESSANTS & CONTROL TECHNOLOGIES  

EPA Science Inventory

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...

431

Nano-structured Exchange-spring Hard Magnetic Thin Films  

NASA Astrophysics Data System (ADS)

In exchange coupled nano-composite magnets, the length scale of the soft phase is limited to twice the domain wall thickness of the hard phase. We investigated the structural and magnetic properties of SmCo5/Co exchange coupled multilayer grown by magnetron sputtering from Sm and Co targets successively at elevated substrate temperature and subsequent in-situ annealing. X-ray diffraction indicates the formation of polycrystalline SmCo5 hard phase. Formation of hard/soft multilayered structure was confirmed through transmission electron microscopy. Magnetic hysteresis measurements showed single phase like behavior, which indicates the soft layer (Co) is well exchange coupled with the neighboring hard phase of SmCo5. Maximum energy product of 15.37 MGOe with HC ? 3.02 kOe was obtained.

Chowdhury, P.; Krishnan, M.; Barshilia, H. C.; Rao, D. V. Sridhara; Shivakumar, C.

432

When does playing hard to get increase romantic attraction?  

PubMed

Folk wisdom suggests playing hard to get is an effective strategy in romantic attraction. However, prior research has yielded little support for this belief. This article seeks to reconcile these contrasting views by investigating how 2 hitherto unconsidered factors, (a) the asymmetry between wanting (motivational) and liking (affective) responses and (b) the degree of psychological commitment, can determine the efficacy of playing hard to get. We propose that person B playing hard to get with person A will simultaneously increase A's wanting but decrease A's liking of B. However, such a result will only occur if A is psychologically committed to pursuing further relations with B; otherwise, playing hard to get will decrease both wanting and liking. Two studies confirm these propositions. We discuss implications for interpersonal attraction and the interplay between emotion and motivation in determining preferences. PMID:23668234

Dai, Xianchi; Dong, Ping; Jia, Jayson S

2014-04-01

433

Flattening fixed-angle chains is strongly NP-hard  

E-print Network

Planar configurations of fixed-angle chains and trees are well studied in polymer science and molecular biology. We prove that it is strongly NP-hard to decide whether a polygonal chain with fixed edge lengths and angles ...

Demaine, Erik D.

434

Multi-Scale Indentation Hardness Testing; A Correlation and Model  

E-print Network

This thesis presents the research results of a correlation and model based on nano and macroindentation hardness measurements. The materials used to develop and test the correlation include bulk tantalum and O1 tool steel. Following the literature...

Bennett, Damon W.

2010-01-20

435

Glassy States in Asymmetric Mixtures of Soft and Hard Colloids  

NASA Astrophysics Data System (ADS)

By employing rheological experiments, mode coupling theory, and computer simulations based on realistic coarse-grained models, we investigate the effects of small, hard colloids on the glassy states formed by large, soft colloids. Multiarm star polymers mimic hard and soft colloids by appropriately varying the number and size of their arms. The addition of hard colloids leads, depending on their concentration, to either melting of the soft glass or the emergence of two distinct glassy states. We explain our findings by depletion of the colloids adjacent to the stars, which leads to an arrested phase separation when the repulsive glass line meets the demixing binodal. The parameter-free agreement between experiment, theory, and simulations suggests the generic nature of our results and opens the route for designing soft-hard colloidal composites with tunable rheology.

Truzzolillo, Domenico; Marzi, Daniela; Marakis, John; Capone, Barbara; Camargo, Manuel; Munam, Abdul; Moingeon, Firmin; Gauthier, Mario; Likos, Christos N.; Vlassopoulos, Dimitris

2013-11-01

436

Isobaric molecular dynamics simulations of hard sphere systems.  

PubMed

We describe an implementation of the Andersen algorithm for simulating the molecular dynamics in the isobaric isoenthalpic (NPH) ensemble for the hard sphere potential. The work is based on the adaptation of the Andersen algorithm to hard spheres by de Smedt et al. For a hard sphere system in the NPH ensemble, the particle velocities are not constant between collisions and we describe an efficient method for handling this part of the dynamics. The method is extended to give an NPT ensemble simulation of hard sphere systems by applying an ad hoc rescaling of the velocities. The accuracy of the algorithms is tested by comparison with traditional NVE simulation results for the structural, thermodynamic, and transport properties. PMID:11415067

Gruhn, T; Monson, P A

2001-06-01

437

Improving the polishing process for Rockwell hardness test block  

E-print Network

Inefficiencies in a Rockwell hardness test block manufacturing process were analyzed. The polishing stage was identified to be the bottleneck with a high reworking rate. An understanding based on the physics of polishing ...

Imani Nejad, Mohammad

2009-01-01

438

Hard ellipses: Equation of state, structure, and self-diffusion.  

PubMed

Despite their fundamental and practical interest, the physical properties of hard ellipses remain largely unknown. In this paper, we present an event-driven molecular dynamics study for hard ellipses and assess the effects of aspect ratio and area fraction on their physical properties. For state points in the plane of aspect ratio (1 ? k ? 9) and area fraction (0.01 ? ? ? 0.8), we identify three different phases, including isotropic, plastic, and nematic states. We analyze in detail the thermodynamic, structural, and self-diffusive properties in the formed various phases of hard ellipses. The equation of state (EOS) is shown for a wide range of aspect ratios and is compared with the scaled particle theory (SPT) for the isotropic states. We find that SPT provides a good description of the EOS for the isotropic phase of hard ellipses. At large fixed ?, the reduced pressure p increases with k in both the isotropic and the plastic phases and, interestingly, its dependence on k is rather weak in the nematic phase. We rationalize the thermodynamics of hard ellipses in terms of particle motions. The static structures of hard ellipses are then investigated both positionally and orientationally in the different phases. The plastic crystal is shown to form for aspect ratios up to k = 1.4, while appearance of the stable nematic phase starts approximately at k = 3. We quantitatively determine the locations of the isotropic-plastic (I-P) transition and the isotropic-nematic (I-N) transition by analyzing the bond-orientation correlations and the angular correlations, respectively. As expected, the I-P transition point is found to increase with k, while a larger k leads to a smaller area fraction where the I-N transition takes place. Moreover, our simulations strongly support that the two-dimensional nematic phase in hard ellipses has only quasi-long-range orientational order. The self-diffusion of hard ellipses is further explored and connections are revealed between the structure and the self-diffusion. We discuss the relevance of our results to the glass transition in hard ellipses. Finally, the results of the isodiffusivity lines are evaluated for hard ellipses and we discuss the effect of spatial dimension on the diffusive dynamics of hard ellipsoidal particles. PMID:23862947

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

2013-07-14

439

A Monte Carlo study of the freezing transition of hard spheres  

NASA Astrophysics Data System (ADS)

A simulation method for fluid-solid transitions, which is based on a modification of the constrained cell model of Hoover and Ree, is developed and tested on a system of hard spheres. In the fully occupied constrained cell model, each particle is confined in its own Wigner-Seitz cell. Constant-pressure simulations of the constrained cell model for a system of hard spheres indicate a point of mechanical instability at a density which is about 64% of the density at the close packed limit. Below that point, the solid is mechanically unstable since without the confinement imposed by the cell walls it will disintegrate to a disordered, fluid-like phase. Hoover and Ree proposed a modified cell model by introducing an external field of variable strength. High values of the external field variable favor configurations with one particle per cell and thus stabilize the solid phase. In this work, the modified cell model of a hard-sphere system is simulated under constant-pressure conditions using tempering and histogram reweighting techniques. The simulations indicate that as the strength of the field is reduced, the transition from the solid to the fluid phase is continuous below the mechanical instability point and discontinuous above. The fluid-solid transition of the hard-sphere system is determined by analyzing the field-induced fluid-solid transition of the modified cell model in the limit in which the external field vanishes. The coexistence pressure and densities are obtained through finite-size scaling techniques and are in good accord with previous estimates.

Nayhouse, Michael; Amlani, Ankur M.; Orkoulas, G.

2011-08-01

440

Correct fair market value calculation needed to avoid regulatory challenges.  

PubMed

In valuing a physician practice for acquisition, it is important for buyers and sellers to distinguish between fair market value and strategic value. Although many buyers would willingly pay for the strategic value of a practice, tax-exempt buyers are required by law to consider only the fair market value in setting a bid price. Valuators must adjust group earnings to exclude items that do not apply to any willing seller and include items that do apply to any willing seller to arrive at the fair market value of the practice. In addition, the weighted average cost of capital (WACC), which becomes the discount rate in the valuation model, is critical to the measure of value of the practice. Small medical practices are assumed to have few hard assets and little long-term debt, and the WACC is calculated on the basis of those assumptions. When a small practice has considerable debt, however, this calculated WACC may be inappropriate for valuing the practice. In every case, evidence that shows that a transaction has been negotiated "at arm's length" should stave off any regulatory challenge. PMID:10170323

Dietrich, M O

1997-09-01

441

Environment and tool for hard real-time systems design  

Microsoft Academic Search

To automate the transition from the specification of a hard real-time system to its design, a design aid tool has been defined. It allows the description of a hard-real-time system using a synchronous visual language, the automatic transformation of the description in order to comply with the temporal constraints indicated in the system specification, and the research of an optimised

L. Carcagno; M. De Michiel; D. Dours; R. Facca; B. Sautet

1994-01-01

442

Test bench development for the radiation Hard GBTX ASIC  

NASA Astrophysics Data System (ADS)

This paper presents the development of the GBTX radiation hard ASIC test bench. Developed for the LHC accelerator upgrade programs, the GBTX implements a bidirectional 4.8 Gb/s link between the radiation hard on-detector custom electronics and the off-detector systems. The test bench was used for functional testing of the GBTX and to evaluate its performance in a radiation environment, by conducting Total Ionizing Dose and Single-Event Upsets tests campaigns.

Leitao, P.; Feger, S.; Porret, D.; Baron, S.; Wyllie, K.; Barros Marin, M.; Figueiredo, D.; Francisco, R.; Da Silva, J. C.; Grassi, T.; Moreira, P.

2015-01-01

443

Dc power supplies and hard-tube power conditioning systems  

SciTech Connect

In this lecture, we shall discuss some of the major characteristics of dc power supplies and hard-tube pulsers, along with many of their PCS limiting properties and several of the more powerful vacuum tubes that are currently available for larger hard-tube pulsers systems. The initial topic will be elementary dc power supplies, operating with standard 60 Hz AC input power. The full-wave bridge design will be discussed in detail, illustrating the majority of the significant circuit parameters.

Sarjeant, W.J.

1980-01-01

444

Support Industrial Hard Real-Time Traffic with Switched Ethernet  

Microsoft Academic Search

This paper presents a simple and efficient switched Ethernet communication protocol for industrial hard real-time LAN applications. The network is founded with end nodes and a switch, and hard real-time communication is handled by software added between the Ethernet protocols and the TCP\\/IP suites. We established a virtual link of the source and destination node by applying admission control based

Alimujiang Yiming; Toshio Eisaka

2005-01-01

445

ELECTROCHEMICAL MACHINING OF HARD PASSIVE ALLOYS WITH PULSE REVERSE CURRENT  

Microsoft Academic Search

Hard passive alloys, such as nickel-based superalloys, are widely used in aircraft and automotive industries due to their 1) excellent strength, 2) stability of microstructure at high temperature and 3) corrosion resistance. However, mechanically machining these hard passive alloys is difficult and expensive. Electrochemical Machining (ECM) has proven to be very effective in machining difficult-to-cut materials because of 1) high

C. D. Zhou; E. J. Taylor; J. J. Sun; L. Gebhart; E. C. Stortz; R. P. Renz

446

Stochastic model of a dense spinless hard-sphere gas  

Microsoft Academic Search

Summary  The motion of a spinless quantum particle subjected to random hard-sphere scatterings is studied in the framework of stochastic\\u000a mechanics. The result is applied to the case of a generic particle of a dense spinless hard-sphere gas leading to a description\\u000a that displays the competition between the thermal and the quantum noise. Finally, the model is discussed in connection with

L. M. Morato; G. Galilei

1991-01-01

447

Palaeoecology and evolution of marine hard substrate communities  

NASA Astrophysics Data System (ADS)

Marine organisms have occupied hard substrates since the Archaean. Shells, rocks, wood and sedimentary hardgrounds offer relatively stable habitats compared to unconsolidated sediments, but the plants and animals which inhabit them must develop means to gain and defend this premium attachment space. Hard substrate communities are formed by organisms with a variety of strategies for adhering to and/or excavating the substrates they inhabit. While mobile grazers, organically attached and even soft-bodied organisms may leave evidence of their former presence in ancient hard substrate communities, a superior fossil record is left by sessile encrusters with mineralised skeletons and by borers which leave trace fossils. Furthermore, encrusters and borers are preserved in situ, retaining their spatial relationships to one another and to the substrate. Spatial competition, ecological succession, oriented growth, and differential utilisation of exposed vs. hidden substrate surfaces can all be observed or inferred. Hard substrate communities are thus excellent systems with which to study community evolution over hundreds of millions of years. Here we review the research on modern and ancient hard substrate communities, and point to some changes that have affected them over geological time scales. Such changes include a general increase in bioerosion of hard substrates, particularly carbonate surfaces, through the Phanerozoic. This is, at least in part, analogous to the infaunalisation trends seen in soft substrate communities. Encrusting forms show an increase in skeletalisation from the Palaeozoic into the Mesozoic and Cenozoic, which may be a response to increasing levels of predation. Hard substrate communities, considering borers and encrusters together, show a rough increase in tiering through the Phanerozoic which again parallels trends seen in soft substrate communities. This extensive review of the literature on living and fossil hard substrate organisms shows that many opportunities remain for large-scale studies of trends through time at the community and clade levels. Palaeontologists will especially benefit by closer integration of their work with that of neontologists, particularly in aspects of ecology such as larval recruitment, competition and succession.

Taylor, P. D.; Wilson, M. A.

2003-07-01

448

Hard ellipses: Equation of state, structure and self-diffusion  

E-print Network

We present an event-driven molecular dynamics study for hard ellipses and assess the effects of aspect ratio and area fraction on their physical properties. For state points in the plane of aspect ratio (k=1-9) and area fraction (phi=0.01-0.8), we identify three different phases, including isotropic, plastic and nematic states. The equation of state (EOS) is shown for a wide range of aspect ratios and is compared with the scaled particle theory (SPT) for the isotropic states. We find that SPT provides a good description of the EOS for the isotropic phase of hard ellipses. At large fixed phi, the reduced pressure p increases with k in both the isotropic and the plastic phases, and interestingly, its dependence on k is rather weak in the nematic phase. We rationalize the thermodynamics of hard ellipses in terms of particle motions. The plastic crystal is shown to form for aspect ratios up to k=1.4, while appearance of the stable nematic phase starts approximately at k=3. We quantitatively determine the locations of the isotropic-plastic (I-P) transition and the isotropic-nematic (I-N) transition by analyzing the bond-orientation correlations and the angular correlations, respectively. As expected, the I-P transition point is found to increase with k, while a larger k leads to a smaller area fraction where the I-N transition takes place. Moreover, our simulations strongly support that the two-dimensional nematic phase in hard ellipses has only quasi-long-range orientational order. The self-diffusion of hard ellipses is further explored and connections are revealed between the structure and the self-diffusion. We discuss the relevance of our results to the glass transition in hard ellipses. Finally, the results of the isodiffusivity lines are evaluated for hard ellipses and we discuss the effect of spatial dimension on the diffusive dynamics of hard ellipsoidal particles.

Wen-Sheng Xu; Yan-Wei Li; Zhao-Yan Sun; Li-Jia An

2012-12-28

449

The Hard X-Ray Sky: Recent Observational Progress  

NASA Technical Reports Server (NTRS)

The last fifty years have witnessed the birth, development, and maturation to full potential of hard X-ray astrophysics. The primary force driving the history of the field has been the development of space-based instrumentation optimized for getting the maximum science out of observations of high-energy photons from astrophysical sources. Hard X-ray telescopes are leading research in areas such as galactic diffuse emission, galactic transients, and active galactic nuclei.

Gehrels, Neil; Cannizzo, John K.

2010-01-01

450

Algorithms for microindentation measurement in automated Vickers hardness testing  

NASA Astrophysics Data System (ADS)

Current algorithms in automated indentation measurement in the context of Vickers microindentation hardness testing suffer from a lack of robustness with respect to entirely missed indentation corner points when applied to real world data sets. Four original algorithms are proposed, discussed and evaluated on a significant data set of indentation images. Three out of these four exhibit accuracy close to human operated hardness testing which has been conducted as a reference technique.

Gadermayr, M.; Maier, A.; Uhl, A.

2011-07-01

451

Hard Braking Events Among Novice Teenage Drivers By Passenger Characteristics.  

PubMed

In a naturalistic study of teenage drivers (N = 42) hard braking events of ?-0.45 g were assessed over the first 6 months of licensure. A total of 1,721 hard braking events were recorded. The video footage of a sample (816) of these events was examined to evaluate validity and reasons for hard braking. Of these, 788 (96.6%) were estimated valid, of which 79.1% were due to driver misjudgment, 10.8% to risky driving behavior, 5.3% to legitimate evasive maneuvers, and 4.8% to distraction. Hard braking events per 10 trips and per 100 miles were compared across passenger characteristics. Hard braking rates per 10 trips among newly licensed teenagers during the first 6 months of licensure were significantly higher when driving with teen passengers and lower with adult passengers than driving alone; rates per 100 miles were lower with adult passengers than with no passengers. Further examination of the results indicates that rates of hard braking with teenage passengers were significantly higher compared with no passengers: 1) for male drivers; 2) during the first month of licensure. The data suggest that that novice teenage driving performance may not be as good or safe when driving alone or with teenage passengers than with adult passengers and provide support for the hypothesis that teenage passengers increase driving risks, particularly during the first month of licensure. PMID:21243109

Simons-Morton, Bruce G; Ouimet, Marie Claude; Wang, Jing; Klauer, Sheila G; Lee, Suzanne E; Dingus, Thomas A

2009-06-22

452

Hard Braking Events Among Novice Teenage Drivers By Passenger Characteristics  

PubMed Central

Summary In a naturalistic study of teenage drivers (N = 42) hard braking events of ??0.45 g were assessed over the first 6 months of licensure. A total of 1,721 hard braking events were recorded. The video footage of a sample (816) of these events was examined to evaluate validity and reasons for hard braking. Of these, 788 (96.6%) were estimated valid, of which 79.1% were due to driver misjudgment, 10.8% to risky driving behavior, 5.3% to legitimate evasive maneuvers, and 4.8% to distraction. Hard braking events per 10 trips and per 100 miles were compared across passenger characteristics. Hard braking rates per 10 trips among newly licensed teenagers during the first 6 months of licensure were significantly higher when driving with teen passengers and lower with adult passengers than driving alone; rates per 100 miles were lower with adult passengers than with no passengers. Further examination of the results indicates that rates of hard braking with teenage passengers were significantly higher compared with no passengers: 1) for male drivers; 2) during the first month of licensure. The data suggest that that novice teenage driving performance may not be as good or safe when driving alone or with teenage passengers than with adult passengers and provide support for the hypothesis that teenage passengers increase driving risks, particularly during the first month of licensure. PMID:21243109

Simons-Morton, Bruce G.; Ouimet, Marie Claude; Wang, Jing; Klauer, Sheila G.; Lee, Suzanne E.; Dingus, Thomas A.

2010-01-01

453

Mongoose: Creation of a Rad-Hard MIPS R3000  

NASA Technical Reports Server (NTRS)

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.

Lincoln, Dan; Smith, Brian

1993-01-01

454

Electronic mechanism of hardness enhancement in transition-metal carbonitrides  

NASA Astrophysics Data System (ADS)

Transition-metal carbides and nitrides are hard materials widely used for cutting tools and wear-resistant coatings. Their hardness is not yet understood at a fundamental level. A clue may lie in the puzzling fact that transition-metal carbonitrides that have the rock-salt structure (such as TiCxN1-x) have the greatest hardness for a valence-electron concentration of about 8.4 per cell, which suggests that the hardness may be determined more by the nature of the bonding than by the conventional microstructural features that determine the hardness of structural metals and alloys. To investigate this possibility, we have evaluated the shear modulus of various transition-metal carbides and nitrides using ab initio pseudopotential calculations. Our results show that the behaviour of these materials can be understood on a fundamental level in terms of their electronic band structure. The unusual hardness originates from a particular band of ? bonding states between the non-metal p orbitals and the metal d orbitals that strongly resists shearing strain or shape change. Filling of these states is completed at a valence-electron concentration of about 8.4, and any additional electrons would go into a higher band which is unstable against shear deformations.

Jhi, Seung-Hoon; Ihm, Jisoon; Louie, Steven G.; Cohen, Marvin L.

1999-05-01

455

Approximate resolution of hard numbering problems  

SciTech Connect

We present a new method for estimating the number of solutions of constraint satisfaction problems. We use a stochastic forward checking algorithm for drawing a sample of paths from a search tree. With this sample, we compute two values related to the number of solutions of a CSP instance. First, an unbiased estimate, second, a lower bound with an arbitrary low error probability. We will describe applications to the Boolean Satisfiability problem and the Queens problem. We shall give some experimental results for these problems.

Bailleux, O.; Chabrier, J.J. [CRID Universite de Bourgogne, Dijon (France)

1996-12-31

456

Values in a Science of Social Work: Values-Informed Research and Research-Informed Values  

ERIC Educational Resources Information Center

While social work must be evaluative in relation to its diverse areas of practice and research (i.e., values-informed research), the purpose of this article is to propose that values are within the scope of research and therefore research on practice should make values a legitimate object of investigation (i.e., research-informed values). In this…

Longhofer, Jeffrey; Floersch, Jerry

2014-01-01

457

Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized  

NASA Technical Reports Server (NTRS)

A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that uses a unique combination of 0.25 micrometer CMOS (complementary metal oxide semiconductor) transistors and high-voltage lateral DMOS (diffusion metal oxide semiconductor) device with high breakdown voltage (greater than 650 V). The high-voltage requirements are achieved by stacking a number of DMOS devices within one module, while two modules can be placed in series to achieve higher voltages. Besides the high-voltage requirements, a second generation prototype is currently being developed to provide improved switching capabilities (rise time and fall time for full range of target voltages and currents), the ability to scale the output voltage to a desired value with good accuracy (few percent) up to 10 kV, to cover a wide range of high-voltage applications. In addition, to ensure miniaturization, long life, and high reliability, the assemblies will require intensive high-voltage electrostatic modeling (optimized E-field distribution throughout the module) to complete the proposed packaging approach and test the applicability of using advanced materials in a space-like environment (temperature and pressure) to help prevent potential arcing and corona due to high field regions. Finally, a single-event effect evaluation would have to be performed and single-event mitigation methods implemented at the design and system level or developed to ensure complete radiation hardness of the module.

Adell, Philippe C.; Mojarradi, Mohammad; DelCastillo, Linda Y.; Vo, Tuan A.

2011-01-01

458

Prestack mid-value filtering  

SciTech Connect

This paper describes mid-value filtering, a specific nonlinear smoothing filtering, and widely used in graphic processing, etc. Mid-value filtering before stack of seismic data can remove wild value (inconceivable particular big value) and improve signal-noise ratio. In view of big data volume before stack, computation efficiency of mid-value filtering is critical to its feasibility. The algorithm used here is sufficiently based on the properties of mid-value filtering, so that the computation efficiency is greatly improved. It is experimentally shown that prestack mid-value filtering can quite well eliminate wild value, abnormal traces as well as surface waves, and raise signal-noise ratio. After lateral low frequency noises are removed by high pass filtering, mid-value filtering works better.

Changlian, X. (Geophysical Research Inst., Bureau of Oil Geophysical Prospecting, Zhuozhou City, Hebei Province (CN))

1992-01-01

459

Evaluation of optical changes of three types of lenses: hard PMMA, hydrogel, and heparin surface modified hard lenses effected by silicone oil, used clinically as a substitute of the vitreous body.  

PubMed

The objective of these investigations was an in vitro evaluation whether silicone oil OXANE of viscosity 5700 cSt clinically used in eye surgery as a substitute of the vitreous body, being in contact with an artificial polymer lens used as an implant of human lens, causes the changes in its optical properties. The paper presents the results of spectral analysis of transmission of visible (VIS) radiation of three types of artificial lenses: hard PMMA, hydrogel, heparin surface modified (HSM) hard PMMA, and the same lenses damaged by YAG laser radiation with an energy increasing from 1.7 mJ to 3.7 mJ, exposed to clinically applied silicone oil. The studies were carried out, in two-week intervals, over a period of 20 weeks. Hard PMMA and HSM lenses were found not to have changed their optical properties after 20 weeks of exposure to silicone oil. The measured transmittance values were within the range of instrumental error (+/- 1%). Optical properties of hydrogel lenses exposed to silicone oils deteriorated with exposure and after 20-week exposure to silicone oil the average transmittance value decreased by about 18%, reaching its final value of 67.08 +/- 2.37% (RSD = 5.56%). A minimal decrease of the initial transmittance values was observed only for the lenses exposed to laser radiation of highest energy (3.7 mJ). After completed exposure to silicone oil, two kinds of lenses were found to have a slightly improved transmittance: hard PMMA lenses by about 4% and HSM lenses by about 2%. On the other hand, in case of hydrogel lenses the deterioration of optical properties to the extent comparable to that of hydrogel lenses not damaged by laser radiation was observed. PMID:12677649

Prokopowicz, Magdalena; Czarnobaj, Katarzyna; Raczy?ska, Krystyna; ?ukasiak, Jerzy; Przyjazny, Andrzej

2002-01-01

460

The Value Trap: Value Buys Risky Growth Stephen Penman*  

E-print Network

The Value Trap: Value Buys Risky Growth Stephen Penman* Columbia Business School, Columbia. However, an investor buying value stocks in hope of those returns may be trapped into buying earnings shocks. These outcomes are demonstrated in a trading strategy that buys stocks based on their earnings

Qian, Ning

461

Teacher Values and Relationship: Factors in Values Education  

ERIC Educational Resources Information Center

Intrigued by the notion that effective teaching is as much about relationship as it is about "technical" proficiency, the author examines the values of teachers that inform classroom relationships, and poses the question as to whether there are particular teacher values that are necessary for quality values education. This question is addressed by…

Brady, Laurie

2011-01-01

462

[Value-Added--Adding Economic Value in the Food Industry].  

ERIC Educational Resources Information Center

This booklet focuses on the economic concept of "value added" to goods and services. A student activity worksheet illustrates how the steps involved in processing food are examples of the concept of value added. The booklet further links food processing to the idea of value added to the Gross National Product (GNP). Discussion questions, a student…

Welch, Mary A., Ed.

1989-01-01

463

Values as lived experience: evolving value sensitive design in support of value discovery  

Microsoft Academic Search

The Value Sensitive Design (VSD) methodology provides a comprehensive framework for advancing a value-centered researchand designagenda. AlthoughVSDprovideshelpful ways of thinking about and designing value-centered com- putational systems, we argue that the specific mechanics of VSD create thorny tensions with respect to value sensitivity. In particular, we examine limitations due to value classifica- tions, inadequateguidanceon empiricaltools for design, and the ways

Christopher A. Le Dantec; Erika Shehan Poole; Susan P. Wyche

2009-01-01

464

Hardness of CaF2 and BaF2 solid lubricants at 25 to 670 deg C  

NASA Technical Reports Server (NTRS)

Plastic deformation is a prominent factor in determining the lubricating value of solid lubricants. Little information is available and its direct measurement is difficult so hardness, which is an indirect measure of this property was determined for fluoride solid lubricant compositions. The Vickers hardness of BaF2 and CaF2 single crystals was measured up to 670 C in a vacuum. The orientation of the BaF2 was near the (013) plane and the CaF2 was about 16 degrees from the degrees from the (1'11) plane. The BaF2 has a hardness of 83 kg/sq mm at the 25 C and 9 at the 600 C. The CaF2 is 170 at 25 C and 13 at 670 C. The decrease in hardness in the temperature range of 25 to 100 C is very rapid and amounts to 40% for both materials. Melts of BaF2 and CaF2 were made in a platinum crucible in ambient air with compositions of 50 to 100 wt% BaF2. The Vickers hardness of these polycrystalline binary compositions at 25 C increased with increasing CaF2 reaching a maximum of 150 kn/sq mm near the eutectic. The polycrystalline CaF2 was 14% softer than that of the single crystal surface and BsF2 was 30% harder than the single crystal surface. It is estimated that the brittle to ductile transition temperature for CaF2 and BaF2 is less than 100 C for the conditions present in the hardness tester.

Deadmore, Daniel L.; Sliney, Harold E.

1987-01-01

465

Electrodeposition and characterization of amorphous Fe-Ni-Cr-based alloys.  

SciTech Connect

Electrodeposition of Fe-Ni-Cr-based alloys was investigated in a divided and undivided cell. Using formic acid (HCOOH) as a complexing agent, a chloride-hypophosphite solution was developed. Effects of composition on the morphology, structure, and corrosion behavior of the alloys were studied. Effects of plating variables on composition of the alloys and current efficiency are also reported. Energy dispersive spectroscopy (EDS) and Auger electron spectroscopy (AES) were used to evaluate alloy composition. These alloys were determined to be amorphous by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Scanning electron microscopy (SEM) photomicrographs were obtained of the surface of selected deposits. The corrosion behavior of the alloys was studied in 0.9 wt % NaCl solution. The alloys containing phosphorus and carbon were found to be less active than those containing only phosphorus or carbon. The corrosion potential of Fe-Ni-Cr-based deposited alloys is more noble the higher the chromium content. Generally, Fe-Ni-Cr-based alloys exhibit a wide passivation range. Knoop hardness of the deposited alloys was determined. It is found that both phosphorus and carbon improved the Knoop hardness value of the deposited alloys.

Kang, J.-C.; Lalvani, S. B.; Melendres, C. A.; Chemical Engineering; Southern Illinois Univ. at Carbondale

1995-01-01

466

Surface disordering and its correlations with properties in argon implanted CR-39 polymer  

NASA Astrophysics Data System (ADS)

The influence of Ar+ implantation induced disordering in the surface layers of the CR-39 polymer on its optical properties and surface hardness has been studied. The specimens were implanted at 130 keV to the doses of 5 × 1014, 1 × 1015, 1 × 1016 Ar+ cm-2. The structural behavior of the pre- and postimplanted specimens was investigated using UV-Visible, Raman, and x-ray diffraction techniques. Formation of disordered graphitelike structures in the implanted layers of polycarbonate has been observed using Raman and UV-Visible spectroscopy. A significant increase in the value of disorder content (Urbach energy) from 0.77 eV to 1.48 eV and a continuous decline in optical bandgap (from 3.43 eV to 2.32 eV) with increasing implantation dose have been observed. This decrease in optical bandgap has been found to have linear dependence on the increase in the Urbach energy, which points toward the formation of disordered structures in the implanted layers of CR-39 polymer. Further, Knoop microhardness is found to be enhanced by a factor of 7 (at a load of 9.8 mN) after implantation. The possible correlation of the increase in Knoop surface hardness with the changes observed as a result of implantation has been established and discussed.

Shekhawat, Nidhi; Aggarwal, Sanjeev; Sharma, Annu; Sharma, S. K.; Deshpande, S. K.; Nair, K. G. M.

2011-04-01

467

Education in Human Values (EHV): Alternative Approach for a Holistic Teaching  

ERIC Educational Resources Information Center

A good and comprehensive education system is expected to create the necessary human capital and knowledge workers who will bring the country to greater heights. In this regards, a holistic education programme is needed which can equip students with both the hard and soft skills required as well as human values. However, the main emphasis in…

Kaliannan, Maniam; Chandran, Suseela Devi

2010-01-01

468

Value of human capital in transition to market: Evidence from Slovenia  

Microsoft Academic Search

The paper summarizes existing hard evidence concerning the changing value of human capital in Slovenia's transition to a market system. It investigates changes in patterns of job mobility (via estimating multinomial logit and hazard models) and changes in the structure of wages (via earnings functions) associated with education, experience, gender, and ethnicity. Data are drawn from unusually rich administrative data

Peter F. Orazem; Milan Vodopivec

1997-01-01

469

Unemployment in Eastern Europe Value of human capital in transition to market: Evidence from Slovenia  

Microsoft Academic Search

The paper summarizes existing hard evidence concerning the changing value of human capital in Slovenia's transition to a market system. It investigates changes in patterns of job mobility (via estimating multinomial logit and hazard models) and changes in the structure of wages (via earnings functions) associated with education, experience, gender, and ethnicity. Data are drawn from unusually rich administrative data

Peter F. Orazem; Milan Vodopivec

470

Value of Human Capital in Transition Market: Evidence from Slovenia September 1996  

Microsoft Academic Search

This paper summarizes existing hard evidence concerning the changing value of human capital in Slovenia's transition to a market system. It investigates changes in patterns of job mobility (via estimating multinomial logit and hazard models) and changes in the structure of wages (via earnings functions) associated with education, experience, gender, and ethnicity. Data are drawn from unusually rich administrative data

Peter Orazem; Milan Vodopivec

1997-01-01

471

Light energy transmission through composite influenced by material shades.  

PubMed

This study investigated the influence of different composite resin shades on light energy transmission through the composite, hardness and cross-link density (CLD). The composite Filtek Z250 was used in shades A1, A2, A3, A3.5 and A4. A quartz tungsten halogen light curing unit was used at an irradiance of 900 mW/cm(2). Thirty specimens were made for each shade. Light energy transmission that passed through the composite was calculated (n=10). Differences in Knoop hardness between the top and bottom (DKH) of the same specimen were calculated (n=10). The Knoop hardness value for each surface was recorded as the average of three indentations (KHN(1)). Thereafter, the specimens were soaked in absolute ethanol for 24hr at room temperature, and hardness was again determined (KHN(2)). The CLD was estimated by the softening effect produced by ethanol, i.e., by decrease in hardness. The percentage of decrease in KHN(2) compared with KHN(1) (PD) in the same specimen was then calculated for both surfaces (n=10). The data were submitted to an ANOVA in different tests (Light energy transmission, Knoop hardness and CLD). The irradiance of light that passed through composite shade A1 (408 mW/cm(2)) was statistically greater than that through shade A2 (376 mW/cm(2)), and was greater through A2 than A3 (359 mW/cm(2)) and through A3 than A3.5 (327 mW/cm(2)); A3.5 showed no statistical difference when compared to A4 (324 mW/cm(2)). The DKH of A4 (20.56%) was not statistically higher than that of A3.5 (20.14%), which was greater than that of A3 (14.08%), A2 (11.65%) and A1 (9.06%). There was no statistical difference in CLD. Darker shades had a significant influence on light energy transmission through dental resin composite and its hardness. However, CLD was not affected by darker dental composite shades. PMID:20179393

Guiraldo, Ricardo Danil; Consani, Simonides; Consani, Rafael Leonardo Xediek; Berger, Sandrine Bittencourt; Mendes, Wilson Batista; Sinhoreti, Mario Alexandre Coelho

2009-01-01

472

Universal values of Canadian astronauts  

NASA Astrophysics Data System (ADS)

Values are desirable, trans-situational goals, varying in importance, that guide behavior. Research has demonstrated that universal values may alter in importance as a result of major life events. The present study examines the effect of spaceflight and the demands of astronauts' job position as life circumstances that affect value priorities. We employed thematic content analysis for references to Schwartz's well-established value markers in narratives (media interviews, journals, and pre-flight interviews) of seven Canadian astronauts and compared the results to the values of National Aeronautics and Space Administration (NASA) and Russian Space Agency (RKA) astronauts. Space flight did alter the level of importance of Canadian astronauts' values. We found a U-shaped pattern for the values of Achievement and Tradition before, during, and after flight, and a linear decrease in the value of Stimulation. The most frequently mentioned values were Achievement, Universalism, Security, and Self-Direction. Achievement and Self Direction are also within the top 4 values of all other astronauts; however, Universalism was significantly higher among the Canadian astronauts. Within the value hierarchy of Canadian astronauts, Security was the third most frequently mentioned value, while it is in seventh place for all other astronauts. Interestingly, the most often mentioned value marker (sub-category) in this category was Patriotism. The findings have important implications in understanding multi-national crew relations during training, flight, and reintegration into society.

Brcic, Jelena; Della-Rossa, Irina

2012-11-01

473

Parameters controlling microstructure and hardness during friction-stir welding of precipitation-hardenable aluminum alloy 6063  

Microsoft Academic Search

The aluminum (Al) alloys 6063-T5 and T4 were friction-stir welded at different tool rotation speeds (R), and then distributions of the microstructure and hardness were examined in these welds. The maximum temperature of the\\u000a welding thermal cycle rose with increasing R values. The recrystallized grain size of the weld increased exponentially with increasing maximum temperature. The relationship\\u000a between the grain

Yutaka S. Sato; Mitsunori Urata; Hiroyuki Kokawa

2002-01-01

474

Structure property relationships of nitride superlattice hard coatings prepared by pulsed laser deposition  

NASA Astrophysics Data System (ADS)

Today, more than 40% of all cutting tools used in machining applications are covered with coatings. Coatings improve wear resistance, increase tool life, enable use at higher speed, and broaden the application range. Superlattices, where thin layers (typically <10 nm) of two different materials (e.g. TiN and AlN) are deposited in an alternating fashion, are widely used commercially. Importantly, the hardness value of a superlattice (e.g. TiN/AlN) can significantly exceed the rule of mixture value. Superlattice coatings built from crystallographically dissimilar materials are not widely studied but hold promise for improvements in performance by allowing for both hardness and toughness to be simultaneously optimized. This is what this thesis is concerned with: a structure-property comparison of isostructural superlattices with corresponding non-isostructural superlattices. In order to grow both isostructural and non-isostructural superlattices from the same set of materials, it is necessary to grow monolithic films in different phases. Towards this end, the synthesis of different phases of AlN, (Ti,Al)N, TaN, and TiN was investigated. Films were grown by pulsed laser deposition in two different chambers that had different base pressures to study the effect of background gases on the phases and orientations of the films. Growth of AlN and (Ti,Al)N films is strongly affected in a chamber that had a base pressure of 10-6 Torr, but the films adopt their stable nitride structures in a chamber with the lower base pressure of 10-8 Torr. TaN adopts either the cubic rock salt structure or its stable hexagonal structure, depending on the growth temperature, while TiN grows as rock salt in all conditions. Single crystal epitaxial superlattices were then grown with different compositions, periodicities, and crystallographic orientations to compare the effect of chemistry, nanostructure, and crystallographic texture on hardness. Finally, the structure-property relationships of non-isostructural (cubic/hexagonal) superlattices are compared with that of the corresponding (111) isostructural cubic superlattices. Nanoindentation measurements revealed higher hardness values for the non-isostructural superlattices as compared to the isostructural coatings at higher periodicities and deposited under identical conditions. These types of non-isostructural superlattices are also highly suited for the commercial coatings where it is not possible to avoid higher periodicities due to the nature of commercial processes. Future directions to exploit these results in commercial coatings are addressed based on our observations.

Patel, Nitin

475

Exposure assessment in the hard metal manufacturing industry with special regard to tungsten and its compounds  

PubMed Central

OBJECTIVES—To assess the exposure to tungsten, cobalt, and nickel in a plant producing hard metals. The main components of hard metals are tungsten carbide and cobalt metal. According to recent studies, these two components may be responsible for both fibrogenic and carcinogenic effects.?METHODS—87 workers were investigated (86 male, one female) with a median age of 42 (range 22-58) and a mean duration of exposure of 13 years (range 1-27 years). Stationary and personal air sampling, and biological monitoring were carried out.?RESULTS—Ambient monitoring yielded maximum tungsten concentrations of 417 µg/m3 in the production of heavy alloys. A maximum cobalt concentration of 343 µg/m3 and a maximum nickel concentration of 30 µg/m3 were found at the sintering workshop. The highest urinary cobalt concentrations were found in the powder processing department. The mean concentration was 28.5 µg/g creatinine and the maximum value was 228 µg/g creatinine. The maximum nickel concentration in urine of 6.3 µg/g creatinine was detected in the department producing heavy alloys. The highest tungsten concentrations excreted in urine were found in grinders and had a mean value of 94.4 µg/g creatinine and a maximum of 169 µg/g creatinine. Due to the different solubility and bioavailability of the substance, there was no correlation between the tungsten concentrations in air and urine on a group basis.?CONCLUSIONS—Despite its low solubility, tungsten carbide is bioavailable. The different bioavailability of tungsten metal and tungsten compounds has to be considered in the interpretation of ambient and biological monitoring data in the hard metal producing industry. The bioavailability increases in the order: tungsten metal, tungsten carbide, tungstenate. Only if both monitoring strategies are considered in combination can a valid and effective definition of high risk groups be derived.???Keywords: tungsten; cobalt; biological monitoring PMID:11555683

Kraus, T; Schramel, P; Schaller, K; Zobelein, P; Weber, A; Angerer, J

2001-01-01

476

Adding Value to Agricultural Products  

E-print Network

You can significantly increase farm income by adding value to agricultural products and marketing those products effectively. This publication explains how to design a value-added product based on consumer preferences and how to build a business...

Anderson, David P.; Hanselka, Daniel

2009-06-01

477

78 FR 78399 - Value Engineering  

Federal Register 2010, 2011, 2012, 2013

...consideration and use of value engineering (VE). VE is a well-established...generated by their value engineering change proposals. Over...involving defense systems, civil works, transportation, construction, engineering, environmental, and...

2013-12-26

478

Effects of Delayed Finishing/Polishing on Surface Roughness, Hardness and Gloss of Tooth-Coloured Restorative Materials  

PubMed Central

Objectives: The aim of this study was to investigate the effect of delayed finishing/polishing on the surface roughness, hardness and gloss of tooth-coloured restorative materials. Methods: Four different tooth-coloured restoratives: a flowable resin composite- Tetric Flow, a hybrid resin composite- Venus, a nanohybrid resin composite- Grandio, and a polyacid modified resin composite- Dyract Extra were used. 30 specimens were made for each material and randomly assigned into three groups. The first group was finished/polished immediately and the second group was finished/polished after 24 hours. The remaining 10 specimens served as control. The surface roughness of each sample was recorded using a laser profilometer. Gloss measurements were performed using a small-area glossmeter. Vickers microhardness measurements were performed from three locations on each specimen surface under 100g load and 10s dwell time. Data for surface roughness and hardness were analyzed by Kruskal Wallis test and data for gloss were subjected to one-way ANOVA and Tukey test (P <.05). Results: The smoothest surfaces were obtained under Mylar strip for all materials. While there were no significant differences in surface roughness of immediate and delayed finished/polished Dyract Extra samples, immediately finished/polished Venus and Grandio samples showed significantly higher roughness than the delayed polished samples (P <.05). In Tetric Flow samples, immediately finishing/polishing provided smoother surface than delayed finishing/polishing (P <.05). The highest gloss values were recorded under Mylar strip for all materials. While delayed finishing/polishing resulted in a significantly higher gloss compared to immediate finishing/polishing in Venus samples (P <.05), no differences were observed between delayed or immediate finishing/polishing for the other materials (P>.05). The lowest hardness values were found under Mylar strip. Delayed finishing/polishing significantly increased the hardness of all materials. Conclusions: The effect of delayed finishing/polishing on surface roughness, gloss and hardness appears to be material dependent. PMID:20046480

Yazici, A. Ruya; Tuncer, Duygu; Antonson, Sibel; Onen, Alev; Kilinc, Evren

2010-01-01

479

Neurocognitive mechanisms underlying value-based decision-making: from core values to economic value  

PubMed Central

Value plays a central role in practically every aspect of human life that requires a decision: whether we choose between different consumer goods, whether we decide which person we marry or which political candidate gets our vote, we choose the option that has more value to us. Over the last decade, neuroeconomic research has mapped the neural substrates of economic value, revealing that activation in brain regions such as ventromedial prefrontal cortex (VMPFC), ventral striatum or posterior cingulate cortex reflects how much an individual values an option and which of several options he/she will choose. However, while great progress has been made exploring the mechanisms underlying concrete decisions, neuroeconomic research has been less concerned with the questions of why people value what they value, and why different people value different things. Social psychologists and sociologists have long been interested in core values, motivational constructs that are intrinsically linked to the self-schema and are used to guide actions and decisions across different situations and different time points. Core value may thus be an important determinant of individual differences in economic value computation and decision-making. Based on a review of recent neuroimaging studies investigating the neural representation of core values and their interactions with neural systems representing economic value, we outline a common framework that integrates the core value concept and neuroeconomic research on value-based decision-making. PMID:23898252

Brosch, Tobias; Sander, David

2013-01-01

480

The Tourism Global Value Chain  

E-print Network

The Tourism Global Value Chain ECONOMIC UPGRADING AND WORKFORCE DEVELOPMENT Michelle Christian 2011 CENTER on GLOBALIZATION, GOVERNANCE & COMPETITIVENESS #12;The Tourism Global Value Chain: Economic: November 17, 2011 #12;The Tourism Global Value Chain: Economic Upgrading and Workforce Development i Table

Richardson, David

481

Values Education: Interdisciplinary Curriculum Strand.  

ERIC Educational Resources Information Center

The instructional objectives of values education to be taught in the K-12 Utah public schools are outlined and cross-referenced to each subject area in the curriculum. It is the responsibility of the schools to help students clarify perceptions and values with respect to self and society. The major categories of values education goals are: rights…

Utah State Office of Education, Salt Lake City. Div. of Curriculum and Instruction.

482

Values of American College Students.  

ERIC Educational Resources Information Center

This study was a reexamination of the norms developed on American college students for the Polyphasic Values Inventory, and a longitudinal study of value change among students 10 years later. A change of values was detected. Greater institutional differences were noted in the original study. (Author/GK)

Kayne, Jon B.; Houston, Samuel R.

1981-01-01

483

Student Development and Values Education.  

ERIC Educational Resources Information Center

In five articles explores the value development of college students. Surveyed student personnel administrators to investigate ethical issues and values in student development and educational approaches to values development. Presents an approach to student ethical development. Discusses a rationale for developmental education considering…

Dalton, John D., Comp.

1982-01-01

484

Do We Really Value Learning?  

Microsoft Academic Search

University faculty think of their institutions as places in which learning is valued and pride themselves on the discovery of new knowledge. Indeed universities have been unusually successful in supporting research and developing new knowledge that has been enormously beneficial to society, and university faculty value learning far more than the average. But some kinds of learning are more valued

John W. Moore

1999-01-01

485

Teaching Values through Children's Literature.  

ERIC Educational Resources Information Center

Suggesting that reading teachers can use children's literature as a vehicle for teaching values, this paper presents an annotated bibliography of children's literature and lesson plans that can help teach the values of honesty, respect, responsibility, compassion, self-discipline, perseverance, and giving. After a brief description of the values,…

Ramp, Ellen; Ridout, Susan Ramp

486

Work Values of Singaporean Adolescents.  

ERIC Educational Resources Information Center

This study attempted to determine the predominant work values among Singaporean students, possible changes in the work values of adolescents as they proceed from early to late adolescence, and the role of gender in forming work values. Using a cross-sectional design and stratified random sampling techniques, a sample of 645 boys and 735 girls was…

Tan, Esther

487

Teaching the Value of Science  

ERIC Educational Resources Information Center

Why and under what conditions might students value their science learning? To find out, the authors observed approximately 400 science classes. They found that although several teachers were amazingly adept at regularly promoting the value of science, many others missed out on important opportunities to promote the value of science. The authors…

Shumow, Lee; Schmidt, Jennifer A.

2015-01-01

488

Negativity bias and basic values.  

PubMed

Basic values explain more variance in political attitudes and preferences than other personality and sociodemographic variables. The values most relevant to the political domain are those likely to reflect the degree of negativity bias. Value conflicts that represent negativity bias clarify differences between what worries conservatives and liberals and suggest that relations between ideology and negativity bias are linear. PMID:24970450

Schwartz, Shalom H

2014-06-01

489

Valuing Your Child Care Business.  

ERIC Educational Resources Information Center

Offers guidelines for putting a monetary value on a child care business. Discusses reasons for valuing the business, types of valuations (book, liquidation, and fair market), fair market valuation formulas, the corporate valuation, valuing assets included in a sale, and using experts. Also offers several tips for selling a child care business. (EV)

Linsmeier, Dave; Richards, Dick; Routzong, Ed

2003-01-01

490

The Logic of Values Clarification  

ERIC Educational Resources Information Center

Traces the origin of the Values Clarification movement in education in Carl Roger's clien-centered therapy and exposes its unwarranted extreme ethical stance. Examines a model episode of values clarification and shows how the theoretical confusions of the Values Clarification proponents are reflected in their actual teaching strategies. (Editor/RK)

Kazepides, A. C.

1977-01-01

491

Surface effects of corrosive media on hardness, friction, and wear of materials  

NASA Technical Reports Server (NTRS)

Hardness, friction, and wear experiments were conducted with magnesium oxide exposed to various corrosive media and also with elemental iron and nickel exposed to water and NaOH. Chlorides such as MgCl2 and sodium containing films were formed on cleaved magnesium oxide surfaces. The MgCl2 films softened the magnesium oxide surfaces and caused high friction and great deformation. Hardness was strongly influenced by the pH value of the HCl-containing solution. The lower the pH, the lower the microhardness. Neither the pH value of nor the immersion time in NaOH containing, NaCl containing, and HNO3 containing solutions influenced the microhardness of magnesium oxide. NaOH formed a protective and low friction film on iron surfaces. The coefficient of friction and the wear for iron were low at concentrations of NaOH higher than 0.01 N. An increase in NaOH concentration resulted in a decrease in the concentration of ferric oxide on the iron surface. It took less NaOH to form a protective, low friction film on nickel than on iron.

Miyoshi, K.; Buckley, D. H.; Rengstorff, G. W. P.; Ishigaki, H.

1985-01-01

492

[Effect of loading time on the Vickers hardness number of dental gold alloys].  

PubMed

The Vickers hardness number (VHN) of pure metals (tin, aluminum, copper and gold) and dental gold alloys was measured using an automatically indenting and reading Vickers hardness tester (AKASHI.AUTOVICK) under a load of 1,000 gf with different loading times of 5 to 55 seconds. The samples of pure metals were cold rolled and softened by heating above recrystallization temperatures. The samples of ADAS No. 5 gold casting alloys were cold rolled, and then subjected to a softening heat treatment by water quenching (Types I, II, III and IV) or a hardening heat treatment by 450-250 degrees C/30 min oven cooling (Types III and IV). The results showed that there were no statistically significant differences between the measured values of VHN of a sample with different loading times as for the metals studied except pure tin which had a VHN of 5-6. The measured values of VHN by AUTOVICK were affected by the brightness of a light source for measurement, and they increased by 1.1 approximately as the voltage of the light source increased by 0.1 V. This was considered to be due to the protuberance caused by plastic flow of metals or slip lines on the surface around the indentation. PMID:2603096

Nakamura, K; Goto, S; Mamada, K; Miyagawa, Y; Sakaida, Y

1989-03-01

493

Metallography studies and hardness measurements on ferritic/martensitic steels irradiated in STIP  

NASA Astrophysics Data System (ADS)

In this work metallography investigations and microhardness measurements have been performed on 15 ferritic/martensitic (FM) steels and 6 weld metals irradiated in the SINQ Target Irradiation Program (STIP). The results demonstrate that all the steels have quite similar martensite lath structures. However, the sizes of the prior austenite grain (PAG) of these steels are quite different and vary from 10 to 86 ?m. The microstructure in the fusion zones (FZ) of electron-beam welds (EBWs) of 5 steels (T91, EM10, MANET-II, F82H and Optifer-IX) is similar in respect to the martensite lath structure and PAG size. The FZ of the inert-gas-tungsten weld (TIGW) of the T91 steel shows a duplex structure of large ferrite gains and martensite laths. The microhardness measurements indicate that the normalized and tempered FM steels have rather close hardness values. The unusual high hardness values of the EBW and TIGW of the T91 steel were detected, which suggests that these materials are without proper tempering or post-welding heat treatment.

Zhang, H.; Long, B.; Dai, Y.

2008-06-01

494

Phase transitions in self-gravitating systems: self-gravitating fermions and hard-sphere models.  

PubMed

We discuss the nature of phase transitions in self-gravitating systems both in the microcanonical and in the canonical ensemble. We avoid the divergence of the gravitational potential at short distances by considering the case of self-gravitating fermions and hard-sphere models. Depending on the values of the parameters, three kinds of phase transitions (of zero, first, and second order) are evidenced. They separate a "gaseous" phase with a smoothly varying distribution of matter from a "condensed" phase with a core-halo structure. We propose a simple analytical model to describe these phase transitions. We determine the value of energy (in the microcanonical ensemble) and temperature (in the canonical ensemble) at the transition point and we study their dependence on the degeneracy parameter (for fermions) or on the size of the particles (for a hard-sphere gas). Scaling laws are obtained analytically in the asymptotic limit of a small short distance cutoff. Our analytical model captures the essential physics of the problem and compares remarkably well with the full numerical solutions. We also stress some analogies with the liquid-gas transition and with the Blume-Emery-Griffiths model with infinite range interactions. In particular, our system presents two tricritical points at which the transition passes from first order to second order. PMID:12059663

Chavanis, Pierre-Henri

2002-05-01

495

Green's function analysis of an ideal hard surface rectangular waveguide  

NASA Astrophysics Data System (ADS)

Green's function analysis of an ideal hard surface rectangular waveguide is proposed for characterization of the modal spectrum of the structure. A decomposition of the hard surface waveguide into perfect electric conductor and perfect magnetic conductor waveguides allows the representation of dyadic Green's function as a superposition of transverse magnetic (TM) and transverse electric (TE) waveguide modes, respectively. In addition, a term corresponding to a transverse electromagnetic (TEM) mode is included in the eigenmode expansion of the Green's dyadic. It is shown that the TEM mode solution can be obtained by solving vector Helmholtz's equation in the zero cutoff limit with the corresponding boundary conditions of electric field on the ideal hard surface. The electric field distribution due to an arbitrarily oriented electric dipole source is illustrated for a few representative TM, TE, and TEM modes propagating in the ideal hard surface rectangular waveguide. The proposed model is verified by analyzing a realistic hard surface square waveguide using the Ansoft High-Frequency Structure Simulator (HFSS).

Huang, Wei; Yakovlev, Alexander B.; Kishk, Ahmed A.; Glisson, Allen W.; Eshrah, Islam A.

2005-10-01

496

Hard Photodisintegration of a Proton Pair in 3He  

E-print Network

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 $^3$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 $\\gamma ^3{\\rm He} \\to p p + n$ 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.

S. J. Brodsky; L. Frankfurt; R. Gilman; J. R. Hiller; G. A. Miller; E. Piasetzky; M. Sargsian; M. Strikman

2003-05-23

497

Hard photodisintegration of a proton pair in 3He  

NASA Astrophysics Data System (ADS)

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 Letter, we discuss the extension of this program to hard photodisintegration of a pp pair in the 3He 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 ? 3He?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.

Brodsky, S. J.; Frankfurt, L.; Gilman, R.; Hiller, J. R.; Miller, G. A.; Piasetzky, E.; Sargsian, M.; Strikman, M.

2004-01-01

498

Identifying high redshift AGNs using X-ray hardness  

E-print Network

The X-ray color (hardness ratio) of optically undetected X-ray sources can be used to distinguish obscured active galactic nuclei (AGNs) at low and intermediate redshift from viable high-redshift (i.e., z>5) AGN candidates. This will help determine the space density, ionizing photon production, and X-ray background contribution of the earliest detectable AGNs. High redshift AGNs should appear soft in X-rays, with hardness ratio HR ~ -0.5, even if there is strong absorption by a hydrogen column density N_H up to 10^23 cm^-2, simply because the absorption redshifts out of the soft X-ray band in the observed frame. Here the X-ray hardness ratio is defined as HR= (H-S)/(H+S), where S and H are the soft and hard band net counts detected by Chandra. High redshift AGNs that are Compton thick (N_H>~10^24 cm^-2) could have HR~0.0 at z>5. However, these should be rare in deep Chandra images, since they have to be >~10 times brighter intrinsically, which implies >~100 times drop in their space density. Applying the hardness criterion (HR<0.0) can filter out about 50% of the candidate high redshift AGNs selected from deep Chandra images.

J. X. Wang; S. Malhotra; J. E. Rhoads; C. A. Norman

2004-05-25

499

Value stream mapping and earned value management : two perspectives on value in product development  

E-print Network

The concepts of value and value stream are crucial to the philosophy of Lean, and a better understanding of how these concepts relate to product development (PD) is essential for the creation of a Lean PD strategy. This ...

Whitaker, Ryan Brent

2005-01-01

500

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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...