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1

Influence of photoactivation method and mold for restoration on the Knoop hardness of resin composite restorations.  

PubMed

The aim of this study was to evaluate in vitro the Knoop hardness in the top and bottom of composite photo activated by different methods when different mold materials were used. Z250 (3M ESPE) and XL2500 halogen unit (3M ESPE) were used. For hardness test, conical restorations were made in extracted bovine incisors (tooth mold) and also metal mold (approximately 2 mm top diameter × 1.5 mm bottom diameter × 2 mm in height). Different photoactivation methods were tested: high-intensity continuous (HIC), low-intensity continuous (LIC), soft-start, or pulse-delay (PD), with constant radiant exposure. Knoop readings were performed on top and bottom restoration surfaces. Data were submitted to two-way ANOVA and Tukey's test (p?=?0.05). On the top, regardless of the mold used, no significant difference in the Knoop hardness (Knoop hardness number, in kilograms-force per square millimeter) was observed between the photoactivation methods. On the bottom surface, the photoactivation method HIC shows higher means of hardness than LIC when tooth and metal were used. Significant differences of hardness on the top and in the bottom were detected between tooth and metal. The photoactivation method LIC and the material mold can interfere in the hardness values of composite restorations. PMID:22971912

Brandt, William Cunha; Silva-Concilio, Lais Regiane; Neves, Ana Christina Claro; de Souza-Junior, Eduardo Jose Carvalho; Sinhoreti, Mario Alexandre Coelho

2013-09-01

2

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

3

Effect of different modes of light modulation on the bond strength and knoop hardness of a dental composite.  

PubMed

This study evaluated the bond strength and Knoop hardness of Z250 composite resin, light activated with XL2500 curing unit, using different protocols: continuous mode - high intensity (CH) (700 mW/cm(2)) for 20 s; continuous mode - low intensity (CL) (150 mW/cm(2)) for 20 s; and pulse-delay with 150 mW/cm(2) for 2(P2), 3(P3), 5(P5), 10(P10) or 15 s (P15), with a 1-min delay, followed by 700 mW/cm(2) for 20 s. For the push-out test (n=10), the bond strength values were obtained using a universal test machine at a crosshead speed of 0.5 mm/min. For Knoop hardness (n=5), the specimens were made using the same light-activation protocols. The hardness measurements were made with a hardness tester at six depths (top, 1, 2, 3, 4, and 5 mm). The data were subjected to ANOVA and Tukey's test at 5% significance level. For bond strength, CL and P5 presented significantly higher mean values (p<0.05) than the other groups. There was no statistically significant difference (p>0.05) between P2, P3, P10, P15 and CH. For Knoop hardness, CH and P15 presented the highest mean values from top surface up to 4 mm depth , while CL presented the lowest hardness mean values (p<0.05). From the depth of 3 mm to 5 mm, the mean values of all groups were significantly lower (p<0.05) than those recorded on top surface. In conclusion, for the pulse-delay method, the initial exposure time can influence bond strength and Knoop hardness of composites. PMID:19180324

Dalli'Magro, Eduardo; Sinhoreti, Mário Alexandre Coelho; Correr, Américo Bortolazzo; Consani, Rafael Leonardo Xediek; Sicoli, Eliseu Augusto; Mendoça, Marcio José; Correr-Sobrinho, Lourenço

2008-01-01

4

INFLUENCE OF A COBALT-CHROMIUM METAL FRAMEWORK ON SURFACE ROUGHNESS AND KNOOP HARDNESS OF VISIBLE LIGHT-POLYMERIZED ACRYLIC RESINS  

PubMed Central

Although visible light-polymerized acrylic resins have been used in removable partial dentures, it is not clear whether the presence of a metal framework could interfere with their polymerization, by possibly reflecting the light and affecting important properties, such as roughness and hardness, which would consequently increase biofilm accumulation. The aim of this study was to compare the roughness and Knoop hardness of a visible light-polymerized acrylic resin and to compare these values to those of water-bath- and microwave-polymerized resins, in the presence of a metal framework. Thirty-six specimens measuring 30.0 × 4.0 ± 0.5 mm of a microwave- (Onda Cryl), a visible light- (Triad) and a water-bath- polymerized (Clássico) (control) acrylic resins containing a cobalt-chromium metal bar were prepared. After processing, specimens were ground with 360 to 1000-grit abrasive papers in a polishing machine, followed by polishing with cloths and 1?m diamond particle suspension. Roughness was evaluated using a profilometer (Surfcorder SE 1700) and Knoop hardness (Kg/mm2) was assayed using a microhardness tester (Shimadzu HMV 2000) at distances of 50, 100, 200, 400 and 800 ?m from the metal bar. Roughness and Knoop hardness means were submitted to two-way ANOVA and compared by Tukey and Kruskal Wallis tests at a 5% significance level Statistically significant differences were found (p<0.05) for roughness and Knoop hardness, with light-polymerized resin presenting the highest values (Ra = 0.11 ?m and hardness between 20.2 and 21.4 Kg/mm2). Knoop values at different distances from the metal bar did not differ statistically (p>0.05). Within the limitations of this in vitro study, it was concluded that the presence of metal did not influence roughness and hardness values of any of the tested acrylic resins. PMID:19089075

de Souza, Joane Augusto; Garcia, Renata Cunha Matheus Rodrigues; Moura, Juliana Silva; Cury, Altair Antoninha Del Bel

2006-01-01

5

Dual resin cement knoop hardness after different activation modes through dental ceramics.  

PubMed

This study investigated the influence of ceramic compositions on Knoop Hardness Number (KHN) immediately and 24 h after polymerization and the effect of activation modes on the KHN of a resin cement. Ten Panavia F 2.0 resin cement discs were activated either directly using curing light, or chemically without light, or through 1.2-thick ceramic discs. The following ceramics were evaluated: Duceram, Cergogold, IPS Empress, IPS Empress 2, Procera, Cercon, In Ceram Alumina and In Ceram Zirconia. The KHN was obtained immediately and after 24-h testing time. Two-way ANOVA and Tukey's test were performed for statistical analysis (p<0.05). Direct activation showed higher KHN than activation through ceramics and chemical activation for both immediate and 24-h post activation. The KHN for 24-h post activation time was higher than that of the immediate post activation time except for the direct activation mode. The glass and di-silicate based ceramics showed higher KHN than alumina- and zirconia-based ceramics, immediately and after 24-h. The reinforced and opaque ceramics had the lowest KHN. The ceramic composition resulted in light attenuation, lower polymerization and lower KHN, and the 24-h testing time promoted an improvement of KHN except for direct activation mode. PMID:20640355

Valentino, Thiago Assunção; Borges, Gilberto Antonio; Borges, Luis Henrique; Vishal, Jain; Martins, Luis Roberto Marcondes; Correr-Sobrinho, Lourenço

2010-01-01

6

Does an additional UV LED improve the degree of conversion and Knoop Hardness of light-shade composite resins?  

PubMed Central

Objective: The purpose of this study was to evaluate the degree of conversion (DC) using FT-Raman spectroscopy and the Knoop hardness (KHN) of composites cured by second and third-generation LED light curing-units (LCU), Radii Cal and Ultralume 5. Methods: Three composites (Filtek Supreme XT, Filtek Z350, and Esthet X) were selected for this study. KHN testing (n=10) was performed with 10 indentations for the top (T) and bottom (B) surfaces. For DC (n=10), both the T and B surfaces were analyzed. Results: For KHN, the three composites differed in hardens. There was a “LCU-surface” interaction, in which Radii Cal showed significantly greater hardens in the B surface. For DC, there was a “composite-surface-LCU” interaction. For the “composite” factor, there was no significant difference between the groups, except for Supreme XT-Radii Cal (T or B surfaces). For the “LCU” factor there was a significant difference for Supreme XT T surface, Ultralume 5 obtained a higher DC. For the Z350 T surface, a significant difference in the DC in which Radii Cal obtained better results. For the “surface” factor, all groups presented T surfaces with a higher DC than the B surfaces, the sole exceptions involved Esthet X-Radii Cal and Z350-Ultralume 5. Conclusion: Knowledge regarding composite composition and the characteristics of LCUs are important for effective polymerization. PMID:23077419

Giorgi, Maria Cecília Caldas; Aguiar, Flávio Henrique Baggio; Soares, Luís Eduardo Silva; Martin, Airton Abrahão; Liporoni, Priscila Christiane Suzy; Paulillo, Luís Alexandre Maffei Sartini

2012-01-01

7

Effect of different initial light intensity by the soft-start photoactivation on the bond strength and Knoop hardness of a dental composite.  

PubMed

This study evaluated the bond strength (push-out method) and Knoop hardness of Z250 composite resin, photoactivated with XL 2500 curing unit, using different protocols: continuous mode (700 mW/cm(2) for 20s) (CO); soft-start (50 mW/cm(2) for 5 s, followed by 700 mW/cm(2) for 15 s) (SS1); soft-start (100 mW/cm(2) for 5 s, followed by 700 mW/cm(2) for 15 s) (SS2); soft-start (150 mW/cm(2) for 5 s, followed by 700 mW/cm(2) for 15s) (SS3); soft-start (200 mW/cm(2) for 5s, followed by 700 mW/cm(2) for 15s) (SS4); soft-start (250 mW/cm(2) for 5 s, followed by 700 mW/cm(2) for 15 s) (SS5); soft-start (300 mW/cm(2) for 5 s, followed by 700 mW/cm(2) for 15 s) (SS6). For the push-out test, the specimens were tested in a universal testing machine at a crosshead speed of 0.5 mm/min. For the hardness test, the specimens were polished for the hardness measurements, using a 50 g load for 15 s. Data were submitted to ANOVA and Tukey's test (alpha=5%). The results of bond strength showed that the SS3 group obtained the highest bond strength when compared to the CO group. There were no significant differences among the other modes in relation to the other groups. Regarding the other results in hardness, there were no significant differences among the groups in the surface region and up to 4 mm depth. PMID:17982548

Dall'Magro, Eduardo; Sinhoreti, Mário Alexandre Coelho; Correr, Américo Bortolazzo; Correr-Sobrinho, Lourenço; Consani, Simonides; Puppin-Rontani, Regina Maria

2007-01-01

8

Knoop microhardness mapping used to compare the efficacy of LED, QTH and PAC curing lights.  

PubMed

This study used a hardness mapping technique to compare the ability of seven curing lights to polymerize five composites. Six curing lights (Sapphire [plasma-arc: PAC], Bluephase16i [light emitting diode: LED], LEDemetron II [LED], SmartLite IQ [LED], Allegro [LED] and UltraLume-5 [Polywave LED]) were compared to an Optilux 501 (halogen: QTH) light. Five resin composites (Vit-1-escence, Tetric Evoceram, Filtek Z250, 4 Seasons and Solitaire 2) were polymerized at 4 mm and 8 mm from the end of the light guide. Four composites were light cured for the following times using these lights: Sapphire (5 seconds), Bluephase16i (5 seconds), LEDemetron II (5 seconds), SmartLite IQ (10 seconds), UltraLume-5 (10 seconds), Allegro (10 seconds) and Optilux 501 (20 seconds). Solitaire 2 required double these irradiation times. On each specimen, the Knoop microhardness (KHN) was measured at 49 locations across a 3 x 3 mm grid to determine the ability of each light to cure each brand of composite. The PAC light delivered the broadest spectrum of wavelengths, the greatest irradiance and hardness values that were 4.7 to 18.1 KHN(50gf) harder than the other lights. The ability of the lights to cure these five composites was ranked from highest to lowest: Sapphire, Optilux 501, Allegro, UltraLume-5, SmartLite IQ, LEDemetron II and Bluephase16i (ANOVA with REGWQ multiple comparison adjustment, p < 0.01). PMID:20166412

Price, Richard B T; Fahey, John; Felix, Christopher M

2010-01-01

9

Elasticity and hardness of nano-polycrystalline boron nitrides: The apparent Hall-Petch effect  

SciTech Connect

Nano-polycrystalline boron nitride (BN) is expected to replace diamond as a superhard and superstiff material. Although its hardening was reported, its elasticity remains unclear and the as-measured hardness could be significantly different from the true value due to the elastic recovery. In this study, we measured the longitudinal-wave elastic constant of nano-polycrystalline BNs using picosecond ultrasound spectroscopy and confirmed the elastic softening for small-grain BNs. We also measured Vickers and Knoop hardness for the same specimens and clarified the relationship between hardness and stiffness. The Vickers hardness significantly increased as the grain size decreased, while the Knoop hardness remained nearly unchanged. We attribute the apparent increase in Vickers hardness to the elastic recovery and propose a model to support this insight.

Nagakubo, A.; Ogi, H., E-mail: ogi@me.es.osaka-u.ac.jp; Hirao, M. [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Sumiya, H. [Advanced Materials R and D Laboratories, Sumitomo Electric Industries, Ltd., Itami, Hyogo 664-0016 (Japan)

2014-08-25

10

Hardness and damage associated with pointed indentations in armor ceramics  

NASA Astrophysics Data System (ADS)

It is empirically known that an armor ceramic should be as hard as or harder than the projectile it intends to defeat. Quasi-static indentation testing is one of the most widely utilized techniques for determining the hardness of armor ceramics. Hardness measurements can also be used to generate other property values (fracture toughness, elastic properties and even the yield strength) that may be relevant to ballistic performance. While the indentation methodologies are simple and straightforward the resultant hardness values for ceramic materials can be influenced by the indenter geometry, indentation load, loading rate, specimen surface finish and ceramic microstructure. This presentation will summarize the results of a study to determine the hardness of a variety of armor-grade ceramics (Al2O3, B 4C, SiC, and WC) with different indenter geometries (Vickers and Knoop) over a range of indentation loads (0.98N to 98N) and discuss the implications for armor ceramics. The resulting data strongly indicates that the best means of determining the hardness of armor ceramics is the use of 19.6N Knoop indentations. While the hardness data and the subsequent analysis clearly support the use of the Knoop methodology to determine the hardness, it does not take into account the response of the ceramic to the indentation process. One response that is continually overlooked is the role of damage and cracking. A detailed understanding of the damage and cracking that occurs during indentation may provide valuable insights to the ballistic performance of the armor ceramics during the earliest stages of impact. To explore this material response a detailed examination of the topography of the indents and the damage and cracking that develops underneath both Knoop and Vickers indentations in a WC and SiC armor ceramic was conducted. The analysis shows that while the same types of cracks are produced in both materials the magnitude of these cracks as well as the type of damage that is produced during the indentation process is significantly different. This information is related to the ballistic performance of each material.

Swab, Jeffrey J.

11

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

12

SOLVENT RETENTION CAPACITY VALUES IN RELATION TO HARD WINTER WHEAT AND FLOUR PROPERTIES AND STRAIGHT-DOUGH BREADMAKING QUALITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Solvent retention capacity (SRC) was investigated in assessing the end-use quality of hard winter wheat (HWW). The four SRC values of 116 HWW flours were determined using 5% lactic acid, 50% sucrose, 5% sodium carbonate, and distilled water. The SRC values were greatly affected by wheat and flour ...

13

Hardness correlation for uranium and its alloys  

SciTech Connect

The hardness of 16 different uranium-titanium (U-Ti) alloys was measured on six (6) different hardness scales (R/sub A/, R/sub B/, R/sub C/, R/sub D/, Knoop, and Vickers). The alloys contained between 0.75 and 2.0 wt % Ti. All of the alloys were solutionized (850/sup 0/C, 1 h) and ice-water quenched to produce a supersaturated martensitic phase. A range of hardnesses was obtained by aging the samples for various times and temperatures. The correlation of various hardness scales was shown to be virtually identical to the hardness-scale correlation for steels. For more-accurate conversion from one hardness scale to another, least-squares-curve fits were determined for the various hardness-scale correlations. 34 figures, 5 tables.

Humphreys, D L; Romig, Jr, A D

1983-03-01

14

Optical Parallel Interference Cancellation with Optical Hard Limiter using the Lowest Threshold Value for Optical CDMA  

Microsoft Academic Search

Multiple Access Interference (MAI) is the major reason for the system degradation in the Optical Code Division Multiple Access (OCDMA). MAI increases with the number of simultaneous users, resulting in deterioration in the performance and limits the maximum number of simultaneous users. Optical Hard Limiter (OHL) is known to improve the performance of the conventional OCDMA system. However, in the

N. Elfadel; M. A. Sadiq; E. Idriss; A. Mohammed; A. A. Aziz; N. M. Saad

2007-01-01

15

Computation of the Shapley Value of Minimum Cost Spanning Tree Games: #P-Hardness and  

E-print Network

RIMS-1690 Computation of the Shapley Value of Minimum Cost Spanning Tree Games: #P UNIVERSITY, Kyoto, Japan #12;Computation of the Shapley Value of Minimum Cost Spanning Tree Games: #P graph, which is #P-complete. We also investigate minimum cost spanning tree games whose Shapley values

16

Effect of inhomogeneity of light from light curing units on the surface hardness of composite resin.  

PubMed

This study investigated the characteristics of output light from different types of light curing units, and their effects on polymerization of light-activated composite resin. Three quartz-tungsten-halogen lamps, one plasma arc lamp, and one LED light curing unit were used. Intensity distribution of light emitted from the light guide tip was measured at 1.0-mm intervals across the guide tip. Distribution of Knoop hardness number on the surface of resin irradiated with the light curing units was also measured. For all units, inhomogeneous distribution of light intensity across the guide tip was observed. Minimum light intensity values were 19-80% of the maximum values. In terms of surface hardness, inhomogeneous distribution was also observed for the materials irradiated with the tested units. Minimum values were 53-92% of the maximum values. Our results indicated that markedly inhomogeneous light emitted from light curing unit could result in inhomogeneous polymerization in some areas of the restoration below the light guide tip. PMID:18309608

Arikawa, Hiroyuki; Kanie, Takahito; Fujii, Koichi; Takahashi, Hideo; Ban, Seiji

2008-01-01

17

Comparison of CT-Number and Gray Scale Value of Different Dental Materials and Hard Tissues in CT and CBCT  

PubMed Central

Introduction: Computed tomography (CT) and cone-beam CT (CBCT) are valuable diagnostic aids for many clinical applications. This study was designed to compare the gray scale value (GSV) and Hounsfield unit (HU) of selected dental materials and various hard tissues using CT or CBCT. Methods and Materials: Three samples of all test materials including amalgam (AM), composite resin (CR), glass ionomer (GI), zinc-oxide eugenol (ZOE), calcium-enriched mixture (CEM) cement, AH-26 root canal sealer (AH-26), gutta-percha (GP), Coltosol (Col), Dycal (DL), mineral trioxide aggregate (MTA), zinc phosphate (ZP), and polycarbonate cement (PC) were prepared and scanned together with samples of bone, dentin and enamel using two CBCT devices, Scanora 3D (S3D) and NewTom VGi (NTV) and a spiral CT (SCT) scanner (Somatom Emotion 16 multislice spiral CT);. Subsequently, the HU and GSV values were determined and evaluated. The data were analyzed by the Kruskal-Wallis and Mann-Whitney U tests. The level of significance was determined at 0.05. Results: There were significant differences among the three different scanners (P<0.05). The differences between HU/GSV values of 12 selected dental materials using NTV was significant (P<0.05) and for S3D and SCT was insignificant (P>0.05). All tested materials showed maximum values in S3D and SCT (3094 and 3071, respectively); however, bone and dentin showed low/medium values (P<0.05). In contrast, the tested materials and tissues showed a range of values in NTV (366 to15383; P<0.05). Conclusion: Scanner system can influence the obtained HU/GSV of dental materials. NTV can discriminate various dental materials, in contrast to S3D/SCT scanners. NTV may be a more useful diagnostic aid for clinical practice. PMID:25386210

Emadi, Naghmeh; Safi, Yaser; Akbarzadeh Bagheban, Alireza; Asgary, Saeed

2014-01-01

18

Contact values of the radial distribution functions of additive hard-sphere mixtures in d dimensions: A new proposal  

E-print Network

The contact values $g_{ij}(\\sigma_{ij})$ of the radial distribution functions of a $d$-dimensional mixture of (additive) hard spheres are considered. A `universality' assumption is put forward, according to which $g_{ij}(\\sigma_{ij})=G(\\eta, z_{ij})$, where $G$ is a common function for all the mixtures of the same dimensionality, regardless of the number of components, $\\eta$ is the packing fraction of the mixture, and $z_{ij}$ is a dimensionless parameter that depends on the size distribution and the diameters of spheres $i$ and $j$. For $d=3$, this universality assumption holds for the contact values of the Percus--Yevick approximation, the Scaled Particle Theory, and, consequently, the Boublik--Grundke--Henderson--Lee--Levesque approximation. Known exact consistency conditions are used to express $G(\\eta,0)$, $G(\\eta,1)$, and $G(\\eta,2)$ in terms of the radial distribution at contact of the one-component system. Two specific proposals consistent with the above conditions (a quadratic form and a rational form) are made for the $z$-dependence of $G(\\eta,z)$. For one-dimensional systems, the proposals for the contact values reduce to the exact result. Good agreement between the predictions of the proposals and available numerical results is found for $d=2$, 3, 4, and 5.

A. Santos; S. B. Yuste; M. Lopez de Haro

2002-07-01

19

Contact values of the radial distribution functions of additive hard-sphere mixtures in d dimensions: A new proposal  

NASA Astrophysics Data System (ADS)

The contact values gij(sigmaij) of the radial distribution functions of a d-dimensional mixture of (additive) hard spheres are considered. A "universality" assumption is put forward, according to which gij(sigma]ij)=G([eta,zij), where G is a common function for all the mixtures of the same dimensionality, regardless of the number of components, eta is the packing fraction of the mixture, and zij=(sigma]i[sigma]j/[sigma]ij)<[sigma]d-1>/<[sigmad> is a dimensionless parameter, n>being the nth moment of the diameter distribution. For d=3, this universality assumption holds for the contact values of the Percus-Yevick approximation, the scaled particle theory, and, consequently, the Boublik-Grundke-Henderson-Lee-Levesque approximation. Known exact consistency conditions are used to express G(eta,0), G(eta,1), and G(eta,2) in terms of the radial distribution at contact of the one-component system. Two specific proposals consistent with the above-mentioned conditions (a quadratic form and a rational form) are made for the z dependence of G(eta,z). For one-dimensional systems, the proposals for the contact values reduce to the exact result. Good agreement between the predictions of the proposals and available numerical results is found for d=2, 3, 4, and 5.

Santos, Andres; Yuste, Santos B.; Lopez de Haro, Mariano

2002-09-01

20

A Terrible Predicament: The De-Evolution of Values in Flannery O'Connor's "A Good Man Is Hard to Find."  

ERIC Educational Resources Information Center

Addresses problems concerning the ways Flannery O'Connor's fiction has been read. Proposes an alternate reading of "A Good Man Is Hard to Find." Suggests the primary theme of the story is the idea that each generation has the responsibility to pass on values to the next. (PM)

Tietz, Stephen; Logsdon, Loren

2001-01-01

21

Comparative evaluation of surface hardness and depth of cure of silorane and methacrylate-based posterior composite resins: An in vitro study  

PubMed Central

Aim: This in vitro study was carried out to compare the effect of LED light curing system on polymerization and hardness of silorane-based and methacrylate-based posterior composite resin. Materials and Methods: A total of 40 samples, 20 of silorane-based composite Filtek P-90 and 20 of methacrylate-based composite Heliomolar HB measuring 2 mm thickness and 8 mm diameter were prepared using Teflon molds and cured using LED curing light. The samples were polished and tested in Knoop hardness tester using a 50-gram load and dwell time of 15 seconds on top and bottom surfaces. The percentage depth of cure was calculated, and statistical analysis was performed using two-way ANOVA test and Student t- test. Results: Higher statistically significant values were seen for both the top and bottom surface hardness in silorane-based resins than methacrylate-based resins on LED light curing. Conclusion: Greater depth of cure was achieved in silorane-based posterior composite than in methacrylate-based posterior composite resins with a statistically significant difference.

Agrawal, Abhishek; Manwar, Narendra U; Hegde, Shubha G; Chandak, Manoj; Ikhar, Anuja; Patel, Aditya

2015-01-01

22

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

23

Monte Carlo simulation of two-dimensional hard body systems with extreme values of the Poisson's ratio  

NASA Astrophysics Data System (ADS)

Monte Carlo computer simulations with variable shape of the periodic box were performed for a few two-dimensional, hard-body models showing elastically isotropic solid phases. Two examples of homo-molecular (i.e. consisting of identical molecules) systems of anisotropic molecules are discussed which form unusual solid phases, showing negative Poisson's ratio and know as auxetic ones, at densities and pressures higher than the elastically isotropic solid phases. Sharp extremes of the Poisson's ratio were observed for both systems at freezing of the orientational degrees of freedom of the molecules: a minimum was observed for the system for which the auxetic phase with frozen rotation is isotropic and a maximum was found for the other system. This indicates that isotropic auxetic phases can have auxetic precursors with much more negative Poisson's ratios than those characterizing the auxetic phases themselves. An example of a hetero-molecular (i.e. mixture consisting of different molecules), elastically isotropic system is also discussed - the polydisperse hard disc system. The simulations revealed a maximum of the Poisson's ratio in the close packing limit at any nonzero polydispersity. Although no manifestation of any auxetic behaviour has been found in this system, the obtained results indicate other unusual effect - a jump (discontinuity) of the Poisson's ratio at close packing when the polydispersity tends to zero. The results obtained in this work demonstrate that the Poisson's ratio can play the role of a sensitive indicator of (at least) some structural changes in solids.

Tretiakov, K. V.; Wojciechowski, K. W.

2005-03-01

24

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

25

Surface Hardness of Resin Cement Polymerized under Different Ceramic Materials  

PubMed Central

Objectives. To evaluate the surface hardness of two light-cured resin cements polymerized under different ceramic discs. Methods. 40 experimental groups of 2 light-cured resin cement specimens (Variolink Veneer and NX3) were prepared and polymerized under 5 different ceramic discs (IPS e.max Press HT, LT, MO, HO, and Cercon) of 4 thicknesses (0.5, 1.0, 1.5, and 2.0?mm), Those directly activated of both resin cements were used as control. After light activation and 37°C storage in an incubator, Knoop hardness measurements were obtained at the bottom. The data were analyzed with three-way ANOVA, t-test, and one-way ANOVA. Results. The KHN of NX3 was of significantly higher than that of Variolink Veneer (P < 0.05). The KHN of resin cement polymerized under different ceramic types and thicknesses was significant difference (P < 0.05). Conclusion. Resin cements polymerized under different ceramic materials and thicknesses showed statistically significant differences in KHN. PMID:22548062

Kesrak, Pimmada; Leevailoj, Chalermpol

2012-01-01

26

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

27

Effects of polydispersity on hard sphere crystals  

Microsoft Academic Search

We use simple models and molecular dynamics simulations to determine the effects of polydispersity delta on the equation of state for hard sphere crystals. Experiments show that the osmotic pressure for poly-(methyl methacrylate) (PMMA) spheres with a poly-(12-hydroxy stearic acid) (PHSA) layer with a 5% polydispersity exceeds the value expected for hard spheres as the volume fraction phi increases, particularly

See-Eng Phan; William B. Russel; Jixiang Zhu; Paul M. Chaikin

1998-01-01

28

Effects of polydispersity on hard sphere crystals  

Microsoft Academic Search

We use simple models and molecular dynamics simulations to determine the effects of polydispersity ? on the equation of state for hard sphere crystals. Experiments show that the osmotic pressure for poly-(methyl methacrylate) (PMMA) spheres with a poly-(12-hydroxy stearic acid) (PHSA) layer with a 5% polydispersity exceeds the value expected for hard spheres as the volume fraction ? increases, particularly

See-Eng Phan; William B. Russel; Jixiang Zhu; Paul M. Chaikin

1998-01-01

29

Ultra-hard polycrystalline diamond synthesized by direct conversion of graphite using multianvil apparatus  

NASA Astrophysics Data System (ADS)

Occurrence of sintered polycrystalline diamonds, such as carbonado and ballas, has been reported in some diamond mines, although the production rate has been very limited and their origin has been unsolved. These polycrystalline diamonds are most valuable in industrial applications because they are often harder than single crystal diamonds, whose hardness depends largely upon the crystallographic directions. Synthesis of pure polycrystalline diamond, however, has been unsuccessful, whereas single crystal diamond has been produced using some catalysts or solvents by high-pressure synthesis since its success in 1950's. Here, we report the first synthesis of a pure massive polycrystalline diamond by direct conversion of graphite without any catalysts/solvents under static high pressure and high temperature. Thus synthesized diamond at pressures 12-25 GPa and temperatures 2300-2500°C was optically transparent and colorless, and consisted of minute crystals of typically 1020 nanometers. Moreover, it was found that the Knoop hardness of the present diamonds is 110-140 GPa, which is higher than those of any known materials, including high quality synthetic type IIa diamond

Irifune, T.; Kurio, A.; Sakamoto, S.; Inoue, T.; Sumiya, H.

2002-12-01

30

Rockwell Hardness Measurement of  

E-print Network

960-5 Rockwell Hardness Measurement of Metallic Materials Samuel R. Low NISTrecommended p r a c t i c e g u i d e Special Publication 960-5 #12;i Rockwell Hardness Measurement of Metallic Materials: (202) 512­2250 Mail: Stop SSOP, Washington, DC 20402-0001 #12;N FOREWORD The Rockwell hardness test

Colton, Jonathan S.

31

BOOKSHELF Hard Disk Drive  

E-print Network

- widths ever higher as higher frequency disturbances become relevant. THE BOOK Hard Disk Drive Servo examples. In chapters 2­5 of Hard Disk Drive Servo Systems it is easy to forget that one is reading a book about disk drive control rather than a book on general control theory. Hard Disk Drive Servo Systems

Benmei, Chen

32

On the Hardness of Decision and Optimisation Problems  

E-print Network

On the Hardness of Decision and Optimisation Problems John Slaney 1 and Sylvie Thi'ebaux 2 Abstract of hard optimisation problems (find, on some measure, the least m such that the given instance x has or not x has a solution of value Ÿ m). This paper examines the relationship between the hardness of op

Thiébaux, Sylvie

33

On the indentation recovery and fleeting hardness of polymers  

E-print Network

On the indentation recovery and fleeting hardness of polymers Catherine A. Tweedie and Krystyn J and volume within 48 h. This viscoelastic response demonstrates that indentation hardness values indentation hardness does not quantitatively or qualitatively predict recoverable work or residual deformation

Van Vliet, Krystyn J.

34

The Dubious Value of Value Neutrality  

ERIC Educational Resources Information Center

Hard science is properly value neutral. But when that ideological neutrality extends to the whole university, the traditional foundation crumbles. Steve Balch laments the moral vacuum that now substitutes for fundamental principles, because it is impossible to frame a program of education--especially in the humanities and social sciences--without…

Balch, Stephen H.

2006-01-01

35

Integrability vs non-integrability: Hard hexagons and hard squares compared  

E-print Network

In this paper we compare the integrable hard hexagon model with the non-integrable hard squares model by means of partition function roots and transfer matrix eigenvalues. We consider partition functions for toroidal, cylindrical, and free-free boundary conditions up to sizes $40\\times40$ and transfer matrices up to 30 sites. For all boundary conditions the hard squares roots are seen to lie in a bounded area of the complex fugacity plane along with the universal hard core line segment on the negative real fugacity axis. The density of roots on this line segment matches the derivative of the phase difference between the eigenvalues of largest (and equal) moduli and exhibits much greater structure than the corresponding density of hard hexagons. We also study the special point $z=-1$ of hard squares where all eigenvalues have unit modulus, and we give several conjectures for the value at $z=-1$ of the partition functions.

M. Assis; J. L. Jacobsen; I. Jensen; J-M. Maillard; B. M. McCoy

2014-06-21

36

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

37

Ordering of hard particles between hard walls  

NASA Astrophysics Data System (ADS)

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

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

2001-05-01

38

Superhard material comparable in hardness to diamond  

Microsoft Academic Search

Superhard boron suboxides, with hardness close to that of diamond, were synthesized from boron\\/boron oxide mixtures. Such hardness is expected when a material's molar volume approaches the value characteristic for diamond. These materials consist of boron-rich phases belonging to the boron-oxygen system. The phase which contains 4 at. % oxygen and a crystal structure related to ..beta..rhombohedral boron can scratch

Andrzej R. Badzian

1988-01-01

39

Superhard material comparable in hardness to diamond  

Microsoft Academic Search

Superhard boron suboxides, with hardness close to that of diamond, were synthesized from boron\\/boron oxide mixtures. Such hardness is expected when a material’s molar volume approaches the value characteristic for diamond. These materials consist of boron-rich phases belonging to the boron-oxygen system. The phase which contains 4 at. % oxygen and a crystal structure related to ?-rhombohedral boron can scratch

Andrzej R. Badzian

1988-01-01

40

Dynamic indentation hardness of materials  

NASA Astrophysics Data System (ADS)

Indentation hardness is one of the simplest and most commonly used measures for quickly characterizing material response under static loads. Hardness may mean resistance to cutting to a machinist, resistance to wear to a tribologist, or a measure of flow stress to a design engineer. In this simple technique, a predetermined force is applied to an indenter for 5-30 seconds causing it to penetrate a specimen. By measuring the load and the indentation size, a hardness value is determined. However, the rate of deformation during indenter penetration is of the order of 10sp{-4}\\ ssp{-1}. In most practical applications, such as high speed machining or impact, material deforms at strain rates in excess of 10sp3{-}10sp5\\ ssp{-1}. At such high rates, it is well established that the plastic behavior of materials is considerably different from their static counterpart. For example, materials exhibit an increase in their yield stress, flow stress, fracture stress, and fracture toughness at high strain rates. Hence, the use of static hardness as an indicator of material response under dynamic loads may not be appropriate. Accordingly, a simple dynamic indentation hardness tester is developed for characterizing materials at strain rates similar to those encountered in realistic situations. The experimental technique uses elastic stress wave propagation phenomena in a slender rod. The technique is designed to deliver a single indentation load of 100-200 mus duration. Similar to static measurements, the dynamic hardness is determined from the measured load and indentation size. Hardness measurements on a range of metals have revealed that the dynamic hardness is consistently greater than the static hardness. The increase in hardness is strongly dependent on the crystal structure of the material. The observed trends in hardness are also found to be consistent with the yield and flow stresses of these materials under uniaxial compression. Therefore, it is suggested that the current technique can be used to assess the rate sensitive nature of engineering materials. To further characterize the plastic strains within the indentation volume, static microhardness measurements were also performed within this region. The contours of microhardness indicated that the plastic zone beneath the indenter is typically smaller under dynamic conditions compared to static loading for rate sensitive materials. To assess the influence of the elastic modulus, yield stress, and work hardening coefficient on the induced plastic volume, finite element simulations were performed using the explicit finite element code LS-DYNA3D. The parametric study revealed that the yield stress has the most significant influence on the size and shape of the plastic zone. The above microstructural and numerical results can be used as guidelines for proper selection and design of engineering materials in applications involving high strain rate loading. Moreover, the contours of microhardness variation can be used to verify the suitability of analytical models developed for characterizing the deformation behavior of engineering materials under complex three dimensional loads.

Koeppel, Brian James

41

Al-Mn coating electrodeposited from ionic liquid on NdFeB magnet with high hardness and corrosion resistance  

NASA Astrophysics Data System (ADS)

Al-Mn coatings were electrodeposited on sintered NdFeB permanent magnet in MnCl2-AlCl3-1-ethyl-3-methylim-idazolium chloride (MnCl2-AlCl3-EMIC) ionic liquid at room temperature. The coatings were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adhesion strength of the coating on NdFeB substrate was evaluated by thermal shock and scratch test. The hardness and corrosion behavior of Al-Mn coating were measured by a Knoop microhardness tester, immersion test and neutral salt spray test respectively. The results showed that the amorphous structure of the deposits was obtained at the current density of 6 mA/cm2, while higher current densities resulted in a mixed structure of amorphous and crystalline. The Al-Mn coating showed excellent adhesion strength on NdFeB substrate with the thermal shock test over 30 cycles and Lc > 80 N. The hardness of Al-Mn coating was up to 5.4 GPa. The amorphous Al-Mn coating showed an anodic sacrificial protection with a low corrosion rate for NdFeB. Meanwhile, the magnetic properties measured by an AMT-4 magnetic measurement device showed that Al-Mn coating did not deteriorate the magnetic property of NdFeB.

Ding, Jingjing; Xu, Bajin; Ling, Guoping

2014-06-01

42

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

43

Hardness Tester for Polyur  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

44

Hard diffraction in CDF  

SciTech Connect

We present Run I results on hard diffraction obtained by the CDF Collaboration in proton-antiproton collisions at the Fermilab Tevatron. They are compared with results from the DESY ep collider HERA and/or theoretical predictions to test factorization in hard diffraction. In addition, the CDF program for diffractive studies in Run II is presented briefly.

K. Terashi

2002-07-12

45

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

46

Hardness of oxynitride glasses: topological origin.  

PubMed

Oxynitride glasses are mixed-anion systems, in which the 2-fold coordinated oxygen atoms have been partially substituted by 3-fold coordinated nitrogen atoms. This so-called nitridation process introduces additional bonds and thereby constrains and compacts the glass network and consequently alters the glass hardness. To explore how and why hardness varies with the degree of nitridation, we have derived a topological model of oxynitride glass hardness using temperature-dependent constraint theory, by which the scaling of glass hardness with nitrogen content can be predicted. A linear model has been derived based on the assumption that the substitution of oxygen atoms with nitrogen atoms is responsible for the hardness increase due to the increase in the number (n) of bond-bending and bond-angular constraints. It turns out that the model agrees with the experimental observation, i.e., an approximate positive linear trend of the hardness change with nitrogen content is observed for a wide range of glass compositions. The topological model may thus be useful for designing new oxynitride glass compositions with targeted hardness values. PMID:25692458

Paraschiv, Georgiana L; Gomez, Sinue; Mauro, John C; Wondraczek, Lothar; Yue, Yuanzheng; Smedskjaer, Morten M

2015-03-12

47

Hard sphere mixtures near a hard wall  

Microsoft Academic Search

Hard spheres with ratios of diameters of 3:5 and 1:3 and at various densities are studied by means of grand canonical ensemble (GCE) simulations, first- and second-order Percus—Yevick theory, scaled particle theory (SPT) and density functional theory (DFT). Generally, but not always, the density profiles of the first-order Percus—Yevick (PY1) theory results are smaller at contact than the GCE simulation

JERZY P. NOWORYTA; DOUGLAS HENDERSON; STEFAN SOKO?OWSKI; KWONG-YU CHAN

1998-01-01

48

Valuing Essays: Essaying Values  

ERIC Educational Resources Information Center

The essay regularly comes under attack. It is criticised for being rigidly linear rather than flexible and reflective. I first challenge this view by examining reasons why the essay should be valued as an important genre. Secondly, I propose that in using the essay form students and academics necessarily exemplify their own critical values. Essays…

Badley, Graham

2010-01-01

49

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.

50

Novel hard compositions and methods of preparation  

DOEpatents

Novel very hard compositions of matter are prepared by using in all embodiments only a minor amount of a particular carbide (or materials which can form the carbide in situ when subjected to heat and pressure); and no strategic cobalt is needed. Under a particular range of conditions, densified compositions of matter of the invention are prepared having hardnesses on the Rockwell A test substantially equal to the hardness of pure tungsten carbide and to two of the hardest commercial cobalt-bonded tungsten carbides. Alternately, other compositions of the invention which have slightly lower hardnesses than those described above in one embodiment also possess the advantage of requiring no tungsten and in another embodiment possess the advantage of having a good fracture toughness value.

Sheinberg, H.

1981-02-03

51

Benchmarking for maximum value.  

PubMed

Speaking at the most recent Healthcare Estates conference, Ed Baldwin, of international built asset consultancy EC Harris LLP, examined the role of benchmarking and market-testing--two of the key methods used to evaluate the quality and cost-effectiveness of hard and soft FM services provided under PFI healthcare schemes to ensure they are offering maximum value for money. PMID:19344004

Baldwin, Ed

2009-03-01

52

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 ...

Mrs. Christian

2007-03-21

53

Spin and hard processes  

E-print Network

It is argued that spin is a fundamental aspect of gauge theories at short distances. As a consequence there are characteristic helicity asymmetries in hard inclusive and exclusive reactions of which a few are discussed.

P. Kroll

2002-10-16

54

Improvement of Imprinted Pattern Uniformity Using Sapphire Mold  

Microsoft Academic Search

In order to improve the adhesion property between a mold and photocurable polymer film in photosolidified imprint lithography, a sapphire plate was used which has advantages such as large Young's modulus, large Knoop hardness value, and large ultimate compressive and tensile forces compared with a quartz plate. The contact angle of water on the sapphire surface is considerably larger than

Masanori Komuro; Yuji Tokano; Jun Taniguchi; Takeshi Kawasaki; Iwao Miyamoto; Hiroshi Hiroshima

2002-01-01

55

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

56

Hardness vs Randomness  

Microsoft Academic Search

We present a simple ne wc onstruction of a pseudorandom bit generator ,b ased on the constant depth generators of (N). It stretches a short string of truly random bits into a long string that looks random to an ya lgorithm from a comple xity class C (eg P, NC, PSPACE, ... )u sing an arbitrary function that is hard

Noam Nisan; Avi Wigderson

1994-01-01

57

Hard Times Hit Schools  

ERIC Educational Resources Information Center

Hard-to-grasp dollar amounts are forcing real cuts in K-12 education at a time when the cost of fueling buses and providing school lunches is increasing and the demands of the federal No Child Left Behind Act still loom larger over states and districts. "One of the real challenges is to continue progress in light of the economy," said Gale Gaines,…

McNeil, Michele

2008-01-01

58

Budgeting in Hard Times.  

ERIC Educational Resources Information Center

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

Parrino, Frank M.

2003-01-01

59

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

60

Novel hard compositions and methods of preparation  

DOEpatents

Novel very hard compositions of matter are prepared by using in all embodiments only a minor amount of a particular carbide (or materials which can form the carbide in situ when subjected to heat and pressure); and no strategic cobalt is needed. Under a particular range of conditions, densified compositions of matter of the invention are prepared having hardnesses on the Rockwell A test substantially equal to the hardness of pure tungsten carbide and to two of the hardest commercial cobalt-bonded tungsten carbides. Alternately, other compositions of the invention which have slightly lower hardnesses than those described above in one embodiment also possess the advantage of requiring no tungsten and in another embodiment possess the advantage of having a good fracture toughness value. Photomicrographs show that the shapes of the grains of the alloy mixture with which the minor amount of carbide (or carbide-formers) is mixed are radically altered from large, rounded to small, very angular by the addition of the carbide. Superiority of one of these hard compositions of matter over cobalt-bonded tungsten carbide for ultra-high pressure anvil applications was demonstrated.

Sheinberg, Haskell (Los Alamos, NM)

1983-08-23

61

Doing Good with Spam Is Hard  

NASA Astrophysics Data System (ADS)

We study economic means to improve network performance in the well-known game theoretic traffic model due to Wardrop. We introduce two sorts of spam flow - auxiliary and adversarial flow - that have no intrinsic value. Auxiliary/adversarial flows are a separate commodity with the sole objective to minimize/maximize the latency at the induced Wardrop equilibrium of the selfish flow. By this means a separate access to the edges is not necessary and the latency of the regulating flow does not distort the arising latency cost. We present networks where auxiliary flow is able to improve the network performance. However, we show that the optimal auxiliary flow is NP-hard to compute and not approximable within a factor of less then frac 43. The minimal amount of auxiliary flow needed to induce the best possible equilibrium is even hard to approximate by any subexponential factor. These hardness results are complemented by proving NP-hardness for the optimal adversarial flow. All hardness results hold even for single-commodity networks.

Hoefer, Martin; Olbrich, Lars; Skopalik, Alexander

62

Novel hard compositions and methods of preparation  

DOEpatents

Novel very hard compositions of matter are prepared by using in all embodiments only a minor amount of a particular carbide (or materials which can form the carbide in situ when subjected to heat and pressure); and no strategic cobalt is needed. Under a particular range of conditions, densified compositions of matter of the invention are prepared having hardnesses on the Rockwell A test substantially equal to the hardness of pure tungsten carbide and to two of the hardest commercial cobalt-bonded tungsten carbides. Alternately, other compositions of the invention which have slightly lower hardnesses than those described above in one embodiment also possess the advantage of requiring no tungsten and in another embodiment possess the advantage of having a good fracture toughness value. Photomicrographs show that the shapes of the grains of the alloy mixture with which the minor amount of carbide (or carbide-formers) is mixed are radically altered from large, rounded to small, very angular by the addition of the carbide. Superiority of one of these hard compositions of matter over cobalt-bonded tungsten carbide for ultra-high pressure anvil applications was demonstrated. 3 figs.

Sheinberg, H.

1983-08-23

63

Eat Smart. Play Hard.  

NSDL National Science Digital Library

The Food and Nutrition Service of the US Department of Agriculture offers online educational material as part of "Eat Smart. Play Hard." -- a public information campaign designed to promote healthy living in American children. While the site and its materials are geared for use by state and local program coordinators, anyone is welcome to download the available information and activity sheets. Click on Cool Stuff for Kids for nutrition-related puzzles and games. Parents Place offers informational brochures and an educational bookmark.

64

Virial coefficients and equation of state of hard chain molecules  

NASA Astrophysics Data System (ADS)

The second, third, and fourth virial coefficients of hard chain molecules with number of segments up to 10 (up to 7 in the case of the fourth one) and the reduced distances L*=1 and 0.5 were determined numerically. For fused hard sphere (FHS) molecules the enlarged fused hard sphere model is introduced which forms a connection to the hard convex geometry and makes it possible to determine the virial coefficients of FHS molecules from the expressions derived for hard convex bodies. Our numerical values of the virial coefficients together with data from literature are used to test the proposed method and to compare its results with values from Wertheim's theory, from its modified version and from the generalized Flory dimer approach. It is found that prediction of the second virial coefficient is very accurate (for L=0.5 the maximum deviation amounts 0.2 percent) and that our values of the third virial coefficient for higher members of the FHS family are superior to those from other considered methods. The model is successfully used to predict geometric characteristics of the hard models of n-butane conformers and to estimate their second virial coefficients. The equation of state of hard prolate spherocylinders in which the nonsphericity parameters of the enlarged FHS model are considered is used to predict the P-V-T behavior of hard dumbbells, hard triatomics, mixture of hard dumbells of different site-site distances, and n-butane taken as a mixture of conformers. In all the cases prediction within error bars is obtained.

Boublík, Tomáš

2003-10-01

65

Regularized 13 moment equations for hard spheres  

NASA Astrophysics Data System (ADS)

The regularized 13 moment equations (R13) of rarefied gas dynamics for a monatomic hard sphere gas in the linear regime are presented. The equations are based on an extended Grad-type moment system, which was systematically reduced by means of the Order of Magnitude Method [Struchtrup, Phys. Fluids 16(11), 3921-3934 (2004)]. The linear Burnett and super-Burnett equations are derived from Chapman-Enskog expansion of the R13 equations. While the Burnett coefficients agree with literature values, this seems to be the first time that super-Burnett coefficients are computed for a hard sphere gas. The equations are considered for stability, and dispersion and damping of sound waves. Boundary conditions are given, and solutions of simple boundary value problems are briefly discussed.

Struchtrup, Henning; Torrilhon, Manuel

2012-11-01

66

Valued Constraint Satisfaction Problems: Hard and Easy Problems  

Microsoft Academic Search

In order to deal with over-constrained Constraint Satisfaction Problems, various extensions of the CSP framework have been considered by taking into account costs, uncertainties, preferences, pri­ orities...Each extension uses a specific mathemat­ ical operator (+, max...) to aggregate constraint violations. In this paper, we consider a simple algebraic frame­ work, related to Partial Constraint Satisfaction, which subsumes most of these

Thomas Schiex; Hélène Fargier; Gérard Verfaillie

1995-01-01

67

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.

68

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

69

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

70

Hard diffraction in CDF  

SciTech Connect

The aim of these studies is to use hard (large Q{sup 2}) processes to investigate the partonic nature of the pomeron. We have measured events with large rapidity gaps between balancing high E{sub T} jets, events with two forward (same-side) jets and a large gap (diffractive di-jet production), diffractive W{sup {+-}} production and diffractive heavy flavor (J/{psi} and b-quark) production. Candidate events of the type double-pomeron {yields} di-jet are observed. I close with a look at the future (Run II).

Albrow, M.G.; CDF Collaboration

1997-10-01

71

Hard Metal Disease  

PubMed Central

In Great Britain there have been no published reports of respiratory disease occurring amongst workers in the hard metal (tungsten carbide) industry. In this paper the clinical and radiological findings in six cases and the pathological findings in one are described. In two cases physiological studies indicated mild alveolar diffusion defects. Histological examination in a fatal case revealed diffuse pulmonary interstitial fibrosis with marked peribronchial and perivascular fibrosis and bronchial epithelial hyperplasia and metaplasia. Radiological surveys revealed the sporadic occurrence and low incidence of the disease. The alterations in respiratory mechanics which occurred in two workers following a day's exposure to dust are described. Airborne dust concentrations are given. The industrial process is outlined and the literature is reviewed. The toxicity of the metals is discussed, and our findings are compared with those reported from Europe and the United States. We are of the opinion that the changes which we would describe as hard metal disease are caused by the inhalation of dust at work and that the component responsible may be cobalt. Images PMID:13970036

Bech, A. O.; Kipling, M. D.; Heather, J. C.

1962-01-01

72

Decreased ventilatory function in hard metal workers.  

PubMed Central

OBJECTIVES: To study individual effects on pulmonary function of exposure to hard metal including cobalt. METHODS: All of the workers in a hard metal company (583 men and 120 women) were examined for smoking, respiratory symptoms, ventilatory function, occupational history of exposure to hard metal, and present exposure to airborne cobalt. The ventilatory function indices (forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory volume in one second per cent (FEV1%), peak expiratory flow (PEF), mid-maximal flow (MMF), forced expiratory flow at 50% vital capacity (V50), forced expiratory flow at 25% vital capacity (V25)) were standardised for height and age and expressed as a percentage of predicted values. RESULTS: Two way analysis of variance of indices of ventilatory function showed that an interaction of hard metal exposure and smoking decreased %V50 for both men and women. Among the currently exposed men, those with asthmatic symptoms (defined as reversible dispnoea with wheeze) had significantly lower %FVC, %FEV1%, %PEF, %MMF, %V50, and %V25 than did workers without asthma. The ventilatory disfunction did not differ between exposed and non-exposed workers with asthmatic symptoms. Even among the men without asthmatic symptoms, %V50 was significantly lowered by the interaction of hard metal exposure and smoking. The multilinear regression analysis of indices of ventilatory function for all of the subjects on sex, smoking (Brinkman index), exposure to hard metal, and asthmatic symptoms showed that asthmatic symptoms and smoking had significant effects on all variables and that the decrease in %V25 was associated with hard metal exposure. In the currently exposed and non-exposed workers, multilinear regression analysis applying indices for cobalt exposure (mean cobalt concentration, duration of exposure, and cumulative dose) showed that not only asthmatic symptoms or smoking but also duration of exposure had significant decreasing effects on %FVC, %MMF, and %V25. CONCLUSIONS: Occupational exposure to hard metal probably causes impairment of ventilatory function in a dose dependent manner. PMID:8704861

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

1996-01-01

73

Value, Value, Where Is the Value?  

ERIC Educational Resources Information Center

Discusses measurement in performance improvement, including the Kirkpatrick four-level model of evaluation for training, and adding value. Highlights include adding value at all levels of organizational performance, for the clients and society; other models of performance improvement; the major focus of HPT (human performance technology); and…

Kaufman, Roger

2003-01-01

74

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

75

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) ...

Mrs. Christian

2007-03-21

76

Hard (State) Problems  

E-print Network

For microquasars, the one time when these systems exhibit steady and powerful jets is when they are in the hard state. Thus, our understanding of this state is key to learning about the disk/jet connection. Recent observational and theoretical results have led to questions about whether we really understand the physical properties of this state, and even our basic picture of this state is uncertain. Here, I discuss some of the recent developments and possible problems with our understanding of this state. Overall, it appears that the strongest challenge to the standard truncated disk picture is the detection of broad iron features in the X-ray spectra, and it seems that either there is a problem with the truncated disk picture or there is a problem with the relativistic reflection models used to explain the broad iron features.

John A. Tomsick

2008-12-16

77

Exciting Hard Spheres  

E-print Network

We investigate the collision cascade that is generated by a single moving incident particle on a static hard-sphere gas. We argue that the number of moving particles at time t grows as t^{xi} and the number collisions up to time t grows as t^{eta}, with xi=2d/(d+2) and eta=2(d+1)/(d+2) and d the spatial dimension. These growth laws are the same as those from a hydrodynamic theory for the shock wave emanating from an explosion. Our predictions are verified by molecular dynamics simulations in d=1 and 2. For a particle incident on a static gas in a half-space, the resulting backsplatter ultimately contains almost all the initial energy.

T. Antal; P. L. Krapivsky; S. Redner

2008-05-25

78

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

79

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

80

Hardness and durability of ring plate valves of piston compressors  

Microsoft Academic Search

At the Moscow Coke and Gas Plant an air compressor has been used to investigate fractured plates of type 30KhGSA steel with HRC hardness values of 32-51. A Rockwell instrument was used to measure the hardness of each fractured plate (10 impressions each side) and each plate was checked by a magnetic luminscence method on a type LD-4 instrument to

V. V. Afonskaya; K. S. Moskvitin; L. Ya. Plshchik; B. A. Gor'kov

1982-01-01

81

Absolute electronegativity and hardness: application to inorganic chemistry  

Microsoft Academic Search

The recent concepts of absolute electronegativity, \\/chi\\/, and absolute hardness, \\/eta\\/, are briefly reviewed. The operational definitions, \\/chi\\/ = (I + A)\\/2 and \\/eta\\/ = (I - A)\\/2, are used to calculate experimental values for a large number of cations, atoms, radicals, and molecules. The resulting values are shown to be in good agreement with chemical behavior, both as to

Ralph G. Pearson

1988-01-01

82

Hard exclusive electroproduction of ?+?- pairs  

NASA Astrophysics Data System (ADS)

Hard exclusive electroproduction of ?+?- pairs off hydrogen and deuterium targets has been studied by the HERMES experiment at DESY. Legendre moments and of the angular distributions of ?+ mesons in the center-of-mass frame of the pair have been measured for the first time. Their dependence on the ?+?- invariant mass can be understood as being due to the interference between relative P-wave (isovector) and S-, D-wave (isoscalar) states of the two pions. The increase in magnitude of as Bjorken x increases is interpreted in the framework of generalized parton distributions as an enhancement of flavour non-singlet qqbar exchange for larger values of x, which leads to a sizable admixture of isoscalar and isovector pion pairs. In addition, the interference between P-wave and D-wave states separately for transverse and longitudinal pion pairs has been studied. The data indicate that in the f2 (1270) region at = 3 GeV2 higher-twist effects can be as large as the leading-twist longitudinal component.

Airapetian, A.; Akopov, N.; Akopov, Z.; Amarian, M.; Ammosov, V. V.; Andrus, A.; Aschenauer, E. C.; Augustyniak, W.; Avakian, R.; Avetissian, A.; Avetissian, E.; Bailey, P.; Balin, D.; Baturin, V.; Beckmann, M.; Belostotski, S.; Bernreuther, S.; Bianchi, N.; Blok, H. P.; Böttcher, H.; Borissov, A.; Borysenko, A.; Bouwhuis, M.; Brack, J.; Brüll, A.; Bryzgalov, V.; Capitani, G. P.; Chen, T.; Ciullo, G.; Contalbrigo, M.; Dalpiaz, P. F.; de Leo, R.; Demey, M.; de Nardo, L.; de Sanctis, E.; Devitsin, E.; di Nezza, P.; Düren, M.; Ehrenfried, M.; Elalaoui-Moulay, A.; Elbakian, G.; Ellinghaus, F.; Elschenbroich, U.; Fabbri, R.; Fantoni, A.; Fechtchenko, A.; Felawka, L.; Frullani, S.; Gapienko, G.; Gapienko, V.; Garibaldi, F.; Garrow, K.; Garutti, E.; Gavrilov, G.; Gharibyan, V.; Graw, G.; Grebeniouk, O.; Greeniaus, L. G.; Gregor, I. M.; Griffioen, K. A.; Hafidi, K.; Hartig, M.; Hasch, D.; Heesbeen, D.; Henoch, M.; Hertenberger, R.; Hesselink, W. H. A.; Hillenbrand, A.; Hoek, M.; Holler, Y.; Hommez, B.; Iarygin, G.; Ivanilov, A.; Izotov, A.; Jackson, H. E.; Jgoun, A.; Kaiser, R.; Kinney, E.; Kisselev, A.; Kopytin, M.; Korotkov, V.; Kozlov, V.; Krauss, B.; Krivokhijine, V. G.; Lagamba, L.; Lapikás, L.; Laziev, A.; Lenisa, P.; Liebing, P.; Linden-Levy, L. A.; Lipka, K.; Lorenzon, W.; Lu, H.; Lu, J.; Lu, S.; Ma, B.-Q.; Maiheu, B.; Makins, N. C. R.; Mao, Y.; Marianski, B.; Marukyan, H.; Masoli, F.; Mexner, V.; Meyners, N.; Mikloukho, O.; Miller, C. A.; Miyachi, Y.; Muccifora, V.; Nagaitsev, A.; Nappi, E.; Naryshkin, Y.; Nass, A.; Negodaev, M.; Nowak, W.-D.; Oganessyan, K.; Ohsuga, H.; Osborne, A.; Pickert, N.; Potashov, S.; Potterveld, D. H.; Raithel, M.; Reggiani, D.; Reimer, P. E.; Reischl, A.; Reolon, A. R.; Riedl, C.; Rith, K.; Rosner, G.; Rostomyan, A.; Rubacek, L.; Rubin, J.; Ryckbosch, D.; Salomatin, Y.; Sanjiev, I.; Savin, I.; Schäfer, A.; Schill, C.; Schnell, G.; Schüler, K. P.; Seele, J.; Seidl, R.; Seitz, B.; Shanidze, R.; Shearer, C.; Shibata, T.-A.; Shutov, V.; Sinram, K.; Sommer, W.; Stancari, M.; Statera, M.; Steffens, E.; Steijger, J. J. M.; Stenzel, H.; Stewart, J.; Stinzing, F.; Tait, P.; Tanaka, H.; Taroian, S.; Tchuiko, B.; Terkulov, A.; Tkabladze, A.; Trzcinski, A.; Tytgat, M.; Vandenbroucke, A.; van der Nat, P.; van der Steenhoven, G.; van Haarlem, Y.; Vetterli, M. C.; Vikhrov, V.; Vincter, M. G.; Vogel, C.; Vogt, M.; Volmer, J.; Weiskopf, C.; Wendland, J.; Wilbert, J.; Ybeles Smit, G.; Ye, Y.; Ye, Z.; Yen, S.; Zihlmann, B.; Zupranski, P.; Hermes Collaboration

2004-10-01

83

Business Value of Solution Architecture  

Microsoft Academic Search

The theory and especially the practice of IT architecture have been developed quite vigorously the last years. However, hardly\\u000a any quantitative data about the value of IT architecture is available. This paper presents the results of a study, which measures\\u000a the value of IT solution architecture for software development projects. The study identifies ten architecture-related project-variables\\u000a and correlates these with

Raymond Slot; Guido Dedene; Rik Maes

2010-01-01

84

Connectivity percolation in suspensions of hard platelets  

E-print Network

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 rod-like particles, we find that for hard plate-like particles the percolation threshold is non-monotonic 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 pre-empting 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 plate-like fillers such as graphene and graphite nanoplatelets.

Maneesh Mathew; Tanja Schilling; Martin Oettel

2012-04-13

85

Superhard material comparable in hardness to diamond  

NASA Astrophysics Data System (ADS)

Superhard boron suboxides, with hardness close to that of diamond, were synthesized from boron/boron oxide mixtures. Such hardness is expected when a material's molar volume approaches the value characteristic for diamond. These materials consist of boron-rich phases belonging to the boron-oxygen system. The phase which contains 4 at. % oxygen and a crystal structure related to ?-rhombohedral boron can scratch diamond faces. During scratching of diamond the suboxide is worn also, and the wear debris is amorphized. Wear on the {100} diamond faces results from a cleavage mechanism which leaves a rough surface covered with cleaved {111} microfaces. The {100} faces are more easily abraded than the {111} diamond faces. Wear on {111} faces consumes much more energy and leaves grooves of plastically deformed diamond.

Badzian, Andrzej R.

1988-12-01

86

Superhard material comparable in hardness to diamond  

SciTech Connect

Superhard boron suboxides, with hardness close to that of diamond, were synthesized from boron/boron oxide mixtures. Such hardness is expected when a material's molar volume approaches the value characteristic for diamond. These materials consist of boron-rich phases belonging to the boron-oxygen system. The phase which contains 4 at. % oxygen and a crystal structure related to ..beta..rhombohedral boron can scratch diamond faces. During scratching of diamond the suboxide is worn also, and the wear debris is amorphized. Wear on the lt. slash/100/ diamond faces results from a cleavage mechanism which leaves a rough surface covered with cleaved lt. slash/111/ microfaces. The lt. slash/100/ faces are more easily abraded than the lt. slash/111/ diamond faces. Wear on lt. slash/111/ faces consumes much more energy and leaves grooves of plastically deformed diamond.

Badzian, A.R.

1988-12-19

87

Concept Mapping: Soft Science or Hard Art?  

NSDL National Science Digital Library

In this paper the scientific side of concept mapping is viewed as "soft science" and the artistic one as "hard art" to imply that the process has some qualities of both, but probably does not fall exclusively within either's domain. In the spirit of hard art, a "gallery" of final concept maps from twenty projects is presented, partly to illustrate more examples of the process when used in a variety of subject areas and for different purposes, and partly for their aesthetic value alone. In the spirit of soft science, two major issues are considered. First, the evidence for the validity and reliability of concept mapping is introduced, along with some suggestions for further research which might be undertaken to examine those characteristics. Second, the role of concept mapping is discussed, with special emphasis on its use in a pattern matching framework. This document is intended for use by novice evaluators and professional evaluators in workshops and conferences.

William Trochim

88

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

89

Beta Backscatter Measures the Hardness of Rubber  

NASA Technical Reports Server (NTRS)

Nondestructive testing method determines hardness, on Shore scale, of room-temperature-vulcanizing silicone rubber. Measures backscattered beta particles; backscattered radiation count directly proportional to Shore hardness. Test set calibrated with specimen, Shore hardness known from mechanical durometer test. Specimen of unknown hardness tested, and radiation count recorded. Count compared with known sample to find Shore hardness of unknown.

Morrissey, E. T.; Roje, F. N.

1986-01-01

90

Hardness Amplification Proofs Require Majority Ronen Shaltiel  

E-print Network

Hardness Amplification Proofs Require Majority Ronen Shaltiel Emanuele Viola April 28, 2010 Abstract Hardness amplification is the fundamental task of converting a -hard function f : {0, 1}n {0, 1} into a (1/2 - )-hard function Amp(f), where f is -hard if small circuits fail to compute f on at least

Viola, Emanuele

91

Load Value Speculation Value Prediction  

E-print Network

1 Load Value Speculation Value Prediction Value Locality Speculative Execution Instruction Level All instructions actually predictable! But loads are most predictable and incur longest latencies. Hence better to predict only loads. On the cache side Even one cache miss per one hundred accesses can

Kucuk, Gurhan

92

Comparison of Asian Noodles from Some Hard White and Hard Red Wheat Flours 1  

Microsoft Academic Search

Cereal Chem. 77(6):816-822 Asian noodles were prepared by an objective laboratory method that included adding optimum water to the dry ingredients, mixing the ingre- dients to homogeneous salt distribution, and sheeting of the dough under low shear stress. The lightness ( L*) values of alkaline- and salt-noodle doughs made from 65% extraction hard white wheat flours (except KS96HW115 flour at

P. A. Seib; X. Liang; F. Guan; Y. T. Liang; H. C. Yang

2000-01-01

93

Hard hadron spectroscopy  

E-print Network

I review lattice QCD calculations that compute the masses of the flavour singlet pseudoscalar mesons. I describe the progress in computing the mass spectrum of light 0++ mesons using lattice QCD. I also compare the results for basic quantities such as fpi and mrho, from various different formalisms of lattice QCD. I discuss the physical value of r0.

Craig McNeile

2009-07-01

94

PROTEINS, HARDNESS AND ALLERGENS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Proteins are key constituents of wheat grain and flour. A number of specific proteins/classes of proteins are critical to the processing and end-use quality, and hence value and utility of wheat. The commercially important proteins of wheat may be broadly classified as glutenins and gliadins of va...

95

Investigations on hard machining of Impax Hi Hard tool steel  

Microsoft Academic Search

In this paper, experimental investigations are carried out by end milling process on hardened tool steel, Impax Hi Hard (Hardness\\u000a 55 HRC) a newly developed tool steel material used by tool and die making industries. Experiments are performed with an aim\\u000a to study performance investigations of machining parameters such as cutting speed, feed, depth of cut and width of cut

Bala Murugan Gopalsamy; Biswanath Mondal; Sukamal Ghosh; Kristian Arntz; Fritz Klocke

2009-01-01

96

Nonconventional hard-metal compositions  

SciTech Connect

A novel hard-metal composition comprising borides and carbides of tungsten, nickel, and iron is made by reaction hot-pressing mixtures of elemental tungsten, nickel, and iron powders with small quantities of boron carbide. The hardness of these compositions is in the range of the hardest conventional tungsten carbide-cobalt compositions. It was subsequently determined that molybdenum can be substituted in part or totally for the tungsten in the composition with a minimum reduction in hardness. This new composition can be used in high-pressure anvils; it sustains higher pressures than commercial carbides without plastic deformation.

Sheinberg, H.

1982-01-01

97

Hard Constraints in Optimization Under Uncertainty  

NASA Technical Reports Server (NTRS)

This paper proposes a methodology for the analysis and design of systems subject to parametric uncertainty where design requirements are specified via hard inequality constraints. Hard constraints are those that must be satisfied for all parameter realizations within a given uncertainty model. Uncertainty models given by norm-bounded perturbations from a nominal parameter value, i.e., hyper-spheres, and by sets of independently bounded uncertain variables, i.e., hyper-rectangles, are the focus of this paper. These models, which are also quite practical, allow for a rigorous mathematical treatment within the proposed framework. Hard constraint feasibility is determined by sizing the largest uncertainty set for which the design requirements are satisfied. Analytically verifiable assessments of robustness are attained by comparing this set with the actual uncertainty model. Strategies that enable the comparison of the robustness characteristics of competing design alternatives, the description and approximation of the robust design space, and the systematic search for designs with improved robustness are also proposed. Since the problem formulation is generic and the tools derived only require standard optimization algorithms for their implementation, this methodology is applicable to a broad range of engineering problems.

Crespo, Luis G.; Giesy, Daniel P.; Kenny, Sean P.

2008-01-01

98

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 summers of Florida. Southern hard clams, Mercenaria campechiensis, may have production traits

Florida, University of

99

Hardness enhancement and crosslinking mechanisms in polystyrene irradiated with high energy ion-beams  

SciTech Connect

Surface hardness values several times larger than steel were produced using high energy ion beams at several hundred keV to MeV. High LET is important for crosslinking. Crosslinking is studied by analyzing hardness variations in response to irradiation parameter such as ion species, energy, and fluence. Effective crosslinking radii at hardness saturation are derived base on experimental data for 350 keV H{sup +} and 1 MeV Ar{sup +} irradiation of polystyrene. Saturation value for surface hardness is about 20 GPa.

Lee, E.H.; Rao, G.R.; Mansur, L.K.

1996-12-31

100

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

PubMed

The liquid crystal phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids are studied by constant pressure Monte Carlo simulations. An extensive study on the phase behavior of linear fluids with a length of 7, 8, 9, 10, 11, 12, 13, 14, 15, and 20 beads is carried out. The phase behavior of partially flexible fluids with a total length of 8, 10, 14, and 15 beads and with different lengths for the linear part is also determined. A precise description of the reduced pressure and of the packing fraction change at the isotropic-nematic coexistence was achieved by performing long simulation runs. For linear fluids, a maximum in the isotropic to nematic packing fraction change is observed for a chain length of 15 beads. The infinite dilution solubility of hard spheres in linear and partially flexible hard-sphere chain fluids is calculated by the Widom test-particle insertion method. To identify the effect of chain connectivity and molecular anisotropy on free volume, solubility is expressed relative to that of hard spheres in a hard sphere fluid at same packing fraction as relative Henry's law constants. A linear relationship between relative Henry's law constants and packing fraction is observed for all linear fluids. Furthermore, this linearity is independent of liquid crystal ordering and seems to be independent of chain length for linear chains of 10 beads and longer. The same linear relationship was observed for the solubility of hard spheres in nematic forming partially flexible fluids for packing fractions up to a value slightly higher than the nematic packing fraction at the isotropic-nematic coexistence. At higher packing fractions, the small flexibility of these fluids seems to improve solubility in comparison with the linear fluids. PMID:23742514

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

2013-05-28

101

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

Code of Federal Regulations, 2010 CFR

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2010-07-01

102

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Code of Federal Regulations, 2010 CFR

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2010-07-01

103

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Code of Federal Regulations, 2013 CFR

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2013-07-01

104

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Code of Federal Regulations, 2012 CFR

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2012-07-01

105

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Code of Federal Regulations, 2011 CFR

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2011-07-01

106

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

Code of Federal Regulations, 2014 CFR

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2014-07-01

107

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

Code of Federal Regulations, 2013 CFR

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2013-07-01

108

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Code of Federal Regulations, 2014 CFR

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2014-07-01

109

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Distinctively colored hard hats, or hard caps; identification for newly...1720-1 Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively...

2012-07-01

110

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Distinctively colored hard hats, or hard caps; identification for newly...1720-1 Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively...

2011-07-01

111

Explanation and the Hard Problem  

Microsoft Academic Search

This paper argues that the form of explanation at issue in the hard problem of consciousness is scientifically irrelevant,\\u000a despite appearances to the contrary. In particular, it is argued that the ‘sense of understanding’ that plays a critical role\\u000a in the form of explanation implicated in the hard problem provides neither a necessary nor a sufficient condition on satisfactory\\u000a scientific

Wayne Wright

2007-01-01

112

Easy Problems are Sometimes Hard  

Microsoft Academic Search

We present a detailed experimental investigation of the easy-hard-easyphase transition for randomly generated instances of satisfiability problems.Problems in the hard part of the phase transition have been extensively usedfor benchmarking satisfiability algorithms. This study demonstrates thatproblem classes and regions of the phase transition previously thought tobe easy can sometimes be orders of magnitude more difficult than the worstproblems in problem

Ian P. Gent; Toby Walsh

1994-01-01

113

Sintered titanium carbide hard alloys  

Microsoft Academic Search

1.A study was made of the preparation of titanium carbide hard alloys with a nickel binder. It is shown that satisfactory mechanical properties (bend strength 107–115 kg\\/mm2, hardness 90–90.5 HRA) are exhibited by 80% TiC-20% Ni alloys produced from fine-milled mixtures by sintering in a vacuum of 5·10-3 mm Hg at a temperature of 1300‡C and an isothermal holding time

G. V. Samsonov; N. N. Sergeev; G. T. Dzodziev; V. K. Vitryanyuk; L. V. Latyaeva

1971-01-01

114

QPX Disease in Hard Clams  

NSDL National Science Digital Library

This New York SeaGrant PDF-brochure examines QPX (Quahog Parasite Unknown, a disease-causing parasite) as it relates to the hard clam fishery in New York. It discusses the origin of QPX, how it infects hard clams, where it has been found, signs of QPX disease, why people in New York should be concerned, and what is being done to control its spread.

Debra Barnes

115

Indentation Size Effect on the Hardness of Zirconia Polycrystals  

NASA Astrophysics Data System (ADS)

The hardness of materials is one of the most important mechanical properties from an engineering point of view. The hardening of metals is realized by the inhibition of dislocation glide, which can be managed through microstructural design. The Hall-Petch hardening H ? d -1/2 , where H is the hardness and d is the grain size, is a wellknown and useful concept of the design. Conversely, the inverse Hall-Petch relation is recently found out in a metal consisted of very fine grains.1,2 Also, it is revealed that the H-value of metals does not depend on only d but indentation size, i.e. the hardness increases with a decrease in indentation size. The indentation size dependence is described through the building-up of geometrically necessary dislocations under a concentrated stress field.3,4 In terms of ceramics, correlation between hardness and microstructure has not been cleared, although a lot of research has been done.5,6 For example, even the grain size dependence of the hardness has not been generally described. The hardness of ceramic nanopolycrystals, which consists of very fine grains with a diameter less than 1?m, has not been examined in detail. Moreover, indentation size effect on the hardness has been scarcely reported. The experimental and theoretical difficulty to estimate the plasticity of a hard elasticplastic material is one of the reasons for the obscurity in the hardness of ceramics. The development and improvement of the nanoindentation technique helps us to make an accurate evaluation of the plasticity of ceramics.

Akatsu, Takashi; Numata, Shingo; Yoshida, Michiyuki; Shinoda, Yutaka; Wakai, Fumihiro

116

Hard Hat Use and Inspection Hard hats are an important piece of personal protective equipment (PPE). Hard hats worn  

E-print Network

Hard Hat Use and Inspection Hard hats are an important piece of personal protective equipment (PPE). Hard hats worn at Berkeley Lab must comply with the requirements of ANSI Z89.1 for impact protection follow manufacturer's recommendations for specific inspection procedures. Hard Hat Inspection - Bullard

Eisen, Michael

117

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).

118

The Complexity of Hardness Amplification and Derandomization  

E-print Network

The Complexity of Hardness Amplification and Derandomization A thesis presented by Emanuele Viola Emanuele Viola The Complexity of Hardness Amplification and Derandomization Abstract This thesis studies of hardness amplification and deran­ domization. Hardness amplification is the task of taking a function

Viola, Emanuele

119

Using Nondeterminism to Amplify Hardness Alexander Healy  

E-print Network

Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Harvard University Emanuele Viola ABSTRACT We revisit the problem of hardness amplification in NP, as recently studied by O) , we amplify to hardness 1/2 - 1/n(1) . 2. If s(n) = 2n(1) , we amplify to hardness 1/2-1/2n(1) . 3

Viola, Emanuele

120

Kernelization and Enumeration: New Approaches to Solving Hard Problems  

E-print Network

and been a fruitful branch of the study of efficient algorithms. By taking advantage of the moderate value of parameters in many practical instances, we can design efficient algorithms for the NP-Hard problems in practice. In this dissertation, we discuss a...

Meng, Jie

2011-08-08

121

Valuing Difference?  

ERIC Educational Resources Information Center

How well are adult and community learning providers doing when it comes to ensuring equality of opportunity (EO) and valuing diversity? Many are in transition from a defensive position of emphasising legal compliance towards making respect for diversity intrinsic to their strategic aims, plans and actions, according to the February edition of…

Watters, Kate

2005-01-01

122

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

123

Hard diffraction and rapidity gaps  

SciTech Connect

The field of hard diffraction, which studies events with a rapidity gap and a hard scattering, has expanded dramatically recently. A review of new results from CDF, D{O}, H1 and ZEUS will be given. These results include diffractive jet production, deep-inelastic scattering in large rapidity gap events, rapidity gaps between high transverse energy jets, and a search for diffractive W-boson production. The combination of these results gives new insight into the exchanged object, believed to be the pomeron. The results axe consistent with factorization and with a hard pomeron that contains both quarks and gluons. There is also evidence for the exchange of a strongly interacting color singlet in high momentum transfer (36 < {vert_bar}t{vert_bar} < 1000 GeV{sup 2}) events.

Brandt, A.

1995-09-01

124

Ordering of hard spheres inside hard cylindrical pores.  

PubMed

Isothermal-isobaric simulations on the ordering behavior of hard spheres upon confinement are presented. The radii of the confining cylinders go from 1.1 to 2 in units of the diameters of the hard spheres adsorbed. In all the range of pressures considered the spheres were located in concentric layers, as many as the radius of the hard cylinder would permit. When the pressure increases, the hard spheres go from being loosely arranged to the formation of ordered structures. This change is marked in all cases by a distinct break in the density of spheres in a narrow pressure range. When the tube radius is smaller than 1.5, the high-pressure ordering is determined by the number of coplanar spheres you can have within a circle of radius equal to that of the confining tube. For wider tubes, the change upon compression is determined by the formation of defected two-dimensional triangular lattices wrapped to fit inside the particular cylinder we are considering. PMID:19658477

Durán-Olivencia, F J; Gordillo, M C

2009-06-01

125

Hard diffraction -- 20 years later  

E-print Network

The idea of diffractive processes with a hard scale involved, to resolve the underlying parton dynamics, was published 1985 and experimentally verified 1988. Today hard diffraction is an active research field with high-quality data and new theoretical models. The trend from Regge-based pomeron models to QCD-based parton level models has given insights on QCD dynamics involving perturbative gluon exchange mechanisms, including the predicted BFKL-dynamics, as well as novel ideas on non-perturbative colour fields and their interactions. Extrapolations to the LHC include the interesting possibility of diffractive Higgs production.

Gunnar Ingelman

2005-12-12

126

Hardness of ion implanted ceramics  

SciTech Connect

It has been established that the wear behavior of ceramic materials can be modified through ion implantation. Studies have been done to characterize the effect of implantation on the structure and composition of ceramic surfaces. To understand how these changes affect the wear properties of the ceramic, other mechanical properties must be measured. To accomplish this, a commercially available ultra low load hardness tester has been used to characterize Al/sub 2/O/sub 3/ with different implanted species and doses. The hardness of the base material is compared with the highly damaged crystalline state as well as the amorphous material.

Oliver, W.C.; McHargue, C.J.; Farlow, G.C.; White, C.W.

1985-01-01

127

Metal ion stabilities correlate with electron affinity rather than hardness or softness  

Microsoft Academic Search

Quantitative metal ion hardness values allow a test of their correlation with aqueous metal ion stability constants of four hard ligands: hydroxide, fluoride, acetate and ammonia. For all four ligands the correlation is weak and dependent on the metal ion charge. For all but fluoride the correlation is in the wrong direction. Metal ion electron affinity correlates much better than

R. Bruce Martin

1998-01-01

128

Quantitative Trait Loci Associated with Milling and Baking Quality in a Soft × Hard Wheat Cross  

Microsoft Academic Search

Hybridization between soft and hard wheat creates new associations among loci. Advantages include an increase Interclass hybridization between soft and hard wheat (Triticum in genetic diversity, a potential increase in grain yield, aestivum L.) results in new genetic combinations of potential value. and transfer of pest resistance genes. Both May et al. We investigated whether interclass hybridization could improve end-

Kimberly Garland Campbell; Patrick L. Finney; Christine J. Bergman; Daisy G. Gualberto; James A. Anderson; Michael J. Giroux; Dimuth Siritunga; Jiaqian Zhu; Francois Gendre; Catherine Roué; Aliette Vérel; Mark E. Sorrells

2001-01-01

129

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

130

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

131

Collision statistics in sheared inelastic hard spheres  

E-print Network

The dynamics of sheared inelastic-hard-sphere systems are studied using non-equilibrium molecular dynamics simulations and direct simulation Monte Carlo. In the molecular dynamics simulations Lees-Edwards boundary conditions are used to impose the shear. The dimensions of the simulation box are chosen to ensure that the systems are homogeneous and that the shear is applied uniformly. Various system properties are monitored, including the one-particle velocity distribution, granular temperature, stress tensor, collision rates, and time between collisions. The one-particle velocity distribution is found to agree reasonably well with an anisotropic Gaussian distribution, with only a slight overpopulation of the high velocity tails. The velocity distribution is strongly anisotropic, especially at lower densities and lower values of the coefficient of restitution, with the largest variance in the direction of shear. The density dependence of the compressibility factor of the sheared inelastic hard sphere system is quite similar to that of elastic hard sphere fluids. As the systems become more inelastic, the glancing collisions begin to dominate more direct, head-on collisions. Examination of the distribution of the time between collisions indicates that the collisions experienced by the particles are strongly correlated in the highly inelastic systems. A comparison of the simulation data is made with DSMC simulation of the Enskog equation. Results of the kinetic model of Montanero et al. {[}Montanero et al., J. Fluid Mech. 389, 391 (1999){]} based on the Enskog equation are also included. In general, good agreement is found for high density, weakly inelastic systems.

Marcus N. Bannerman; Thomas E. Green; Paul Grassia; Leo Lue

2009-03-24

132

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

133

Submicron cubic boron nitride as hard as diamond  

NASA Astrophysics Data System (ADS)

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

Liu, Guoduan; Kou, Zili; Yan, Xiaozhi; Lei, Li; Peng, Fang; Wang, Qiming; Wang, Kaixue; Wang, Pei; Li, Liang; Li, Yong; Li, Wentao; Wang, Yonghua; Bi, Yan; Leng, Yang; He, Duanwei

2015-03-01

134

FATIGUE OF BIOMATERIALS: HARD TISSUES.  

PubMed

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

2010-09-01

135

Playing the Numbers: Hard Choices  

ERIC Educational Resources Information Center

Stateline.org recently called this recession the worst in 50 years for state budgets. As has been the case in past economic downturns, higher education looks to be particularly hard hit. Funds from the American Recovery and Relief Act may have postponed some of the difficulty for many colleges and universities, but the outlook for public higher…

Doyle, William R.

2009-01-01

136

Materials science Nanotubes get hard  

E-print Network

Materials science Nanotubes get hard under pressure Proc. Natl Acad. Sci. USA doi:10.1073/pnas.0405877101 (2004) When Zhongwu Wang et al. squeezed carbon nanotubes in a diamond anvil cell, they made nanotubes into diamond itself: the carbon material formed under compression at room temperature seems

Downs, Robert T.

137

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.

138

Hard electroproduction of vector mesons  

E-print Network

It is reported on a global analysis of hard vector-meson electroproduction which is based on the handbag factorization. The generalized parton distributions are constructed from their forward limits with the help of double distributions and the partonic subprocesses are calculated within the modified perturbative approach.

P. Kroll

2008-06-16

139

Formation of Diamond-like Carbon Thin Films by Ion Beam Assisted Deposition Method  

NASA Astrophysics Data System (ADS)

The mechanical properties of diamond-like carbon (DLC) thin films on SUS304 substrate have been studied. DLC thin films were prepared by the ion beam assisted deposition method. In this method, He+ ion irradiation was carried out in a C2H4 gas atmosphere. He+ ions were accelerated at an energy of 15 keV, and the ion beam current densities were changed from 10 to 100 ?A/cm2. Atomic concentration and structure of the films were investigated by X-ray photoelectron spectroscopy and Raman spectroscopy. The mechanical properties of hardness and friction coefficient were determined using the Knoop hardness tester and the pin-on-disk tribometer. The DLC thin films had amorphous structure that composed chiefly of graphite and disorder of graphite states. The Knoop hardness of the films increased with increasing He+ ion current density, and the film prepared at a current density of 80 ?A/cm2 showed the maximum Knoop hardness value of 890 kgf/cm2. The friction coefficient of the film prepared at a current density of 60 ?A/cm2 indicated lower value than that of the other current densities. From these results, it was cleared that the mechanical properties and structure of DLC thin films were greatly affected by the He+ ion beam current density.

Nakamura, Isao; Takano, Ichiro; Sasaki, Michiko; Takashika, Masaru; Kasiwagi, Tomohumi; Sawada, Yohio

140

Mixed Integer Linear Programming Method for Absolute Value Equations  

Microsoft Academic Search

We formulate the NP-hard absolute value equation as linear complementary problem when the singular values of A exceed one, and we proposed a mixed integer linear programming method to absolute value equation problem. The effectiveness of the method is demonstrated by its ability to solve random problems. Index Terms—absolute value equation; linear complementary problem; mixed integer linear programming. The basic

Longquan Yong

2009-01-01

141

Application of the hard and soft acids and bases concept to explain ligand coordination in double salt structures  

Microsoft Academic Search

The coordination polyhedra in 43 double salt structures are examined. Each structure is formed by at least two kinds of polyhedra. The differences in the environment around the metal ions are explained using HSAB concept. The values of hardness for 25 cations are calculated according to Klopman. A factor chi = Hacid.Hbase, where H is the hardness value, is introduced.

Christo Balarew; Rumen Duhlev

1984-01-01

142

Depletion potential in colloidal mixtures of hard spheres and platelets  

E-print Network

The depletion potential between two hard spheres in a solvent of thin hard disclike platelets is investigated by using either the Derjaguin approximation or density functional theory. Particular attention is paid to the density dependence of the depletion potential. A second-order virial approximation is applied, which yields nearly exact results for the bulk properties of the hard-platelet fluid at densities two times smaller than the density of the isotropic fluid at isotropic-nematic phase coexistence. As the platelet density increases, the attractive primary minimum of the depletion potential deepens and an additional small repulsive barrier at larger sphere separations develops. Upon decreasing the ratio of the radius of the spheres and the platelets, the primary minimum diminishes and the position of the small repulsive barrier shifts to smaller values of the sphere separation.

L. Harnau; S. Dietrich

2004-01-21

143

Hard-sphere fluids in very narrow cylindrical pores  

NASA Astrophysics Data System (ADS)

Properties of fluids in narrow pores have been studied extensively in recent years. In this paper, we study the pore radius dependence of hard-sphere fluids in very narrow cylindrical pores via Monte Carlo simulations to explore the crossover from strictly one-dimensional to quasi-one-dimensional fluids. Our study shows that this crossover is not simple. We observe, for constant pressure, an unexpected but interesting nonmonotonic variation of density and compressibility as the pore radius is varied near the value of one hard-sphere diameter (?hs). These results are related to the onset of configurations with two or more nearest-neighbor hard spheres across the diameter of the cylindrical pore.

Mon, K. K.; Percus, J. K.

2000-02-01

144

Valuing Stillbirths.  

PubMed

Estimates of the burden of disease assess the mortality and morbidity that affect a population by producing summary measures of health such as quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs). These measures typically do not include stillbirths (fetal deaths occurring during the later stages of pregnancy or during labor) among the negative health outcomes they count. Priority-setting decisions that rely on these measures are therefore likely to place little value on preventing the more than three million stillbirths that occur annually worldwide. In contrast, neonatal deaths, which occur in comparable numbers, have a substantial impact on burden of disease estimates and are commonly seen as a pressing health concern. In this article we argue in favor of incorporating unintended fetal deaths that occur late in pregnancy into estimates of the burden of disease. Our argument is based on the similarity between late-term fetuses and newborn infants and the assumption that protecting newborns is important. We respond to four objections to counting stillbirths: (1) that fetuses are not yet part of the population and so their deaths should not be included in measures of population health; (2) that valuing the prevention of stillbirths will undermine women's reproductive rights; (3) that including stillbirths implies that miscarriages (fetal deaths early in pregnancy) should also be included; and (4) that birth itself is in fact ethically significant. We conclude that our proposal is ethically preferable to current practice and, if adopted, is likely to lead to improved decisions about health spending. PMID:25395144

Phillips, John; Millum, Joseph

2014-11-14

145

Effects of polydispersity on hard sphere crystals  

NASA Astrophysics Data System (ADS)

We use simple models and molecular dynamics simulations to determine the effects of polydispersity ? on the equation of state for hard sphere crystals. Experiments show that the osmotic pressure for poly-(methyl methacrylate) (PMMA) spheres with a poly-(12-hydroxy stearic acid) (PHSA) layer with a 5% polydispersity exceeds the value expected for hard spheres as the volume fraction ? increases, particularly for ?>0.60. Mean field theory predicts a higher osmotic pressure with increasing polydispersity, but the effects are only significant for ?>0.10. Molecular dynamics simulations with ?=0.05 bound the equation of state between a metastable disordered upper limit and a crystalline organized polydisperse (possibly) lower limit. The pressure for the PMMA-PHSA spheres lies close to the organized polydisperse limit, indicating a preference for a crystalline ordered arrangement where smaller particles surround larger ones. Thus, the higher osmotic pressure seen in the equation of state of PMMA-PHSA spheres is a direct effect of polydispersity, manifest as a pronounced reduction in the crystalline close packed volume fraction from ?max(FCC, ?=0)=0.7404 to ?max(FCC, ?=0.1)=0.665. The random close packing ?max(RCP) is almost independent of polydispersity. This leads to a crossing of values of ?max(FCC) and ?max(RCP) and hence a possible terminal polydispersity of 0.12±0.01, consistent with other simulations, theories, and experiments. Since our results do not include size fractionation of the liquid and solid, the exact meaning of this crossing is unclear and its agreement with previously reported terminal polydispersities may be coincidental.

Phan, See-Eng; Russel, William B.; Zhu, Jixiang; Chaikin, Paul M.

1998-06-01

146

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.

Good, Morris S. (Richland, WA); Schuster, George J. (Kennewick, WA); Skorpik, James R. (Kennewick, WA)

1997-01-01

147

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

148

Rapidity Gaps in Hard Photoproduction  

E-print Network

Recent results obtained from studies of diffractive processes in hard photoproduction performed by the ZEUS collaboration using data delivered by HERA in 1993 and 1994 are presented. In particular, we have found that $(7 \\pm 3)$\\% of events with two jets at a pseudorapidity interval of 3.5 to 4 are inconsistent with a non-diffractive production mechanism. These events may be interpreted as arising due to the exchange of a colour singlet object of negative squared invariant mass ($-t$) around 40~GeV$^2$. We have also probed the structure of the exchanged colour singlet object in low--$t$ diffractive scattering. By comparing the results from photoproduction and electroproduction processes we find that between 30\\% and 80\\% of the momentum of the exchanged colour singlet object which is carried by partons is due to hard gluons.

L. E. Sinclair

1996-06-18

149

Why Are Drugs So Hard to Quit?  

MedlinePLUS Videos and Cool Tools

Video: Why Are Drugs So Hard to Quit? Your browser does not support inline frames or is currently configured not to display inline ... link under the video: In English: Why Are Drugs So Hard to Quit? En español: ¿Por Qué ...

150

CMS Results on Hard Diffraction  

E-print Network

In these proceedings we present CMS results on hard diffraction. Diffractive dijet production in pp collisions at $\\sqrt{s}$=7 TeV is discussed. The cross section for dijet production is presented as a function of $\\tilde{\\xi}$, representing the fractional momentum loss of the scattered proton in single-diffractive events. The observation of W and Z boson production in events with a large pseudo-rapidity gap is also presented.

Christina Mesropian on behalf of the CMS collaboration

2013-10-20

151

Microwave assisted hard rock cutting  

DOEpatents

An apparatus for the sequential fracturing and cutting of subsurface volume of hard rock (102) in the strata (101) of a mining environment (100) by subjecting the volume of rock to a beam (25) of microwave energy to fracture the subsurface volume of rock by differential expansion; and , then bringing the cutting edge (52) of a piece of conventional mining machinery (50) into contact with the fractured rock (102).

Lindroth, David P. (Apple Valley, MN); Morrell, Roger J. (Bloomington, MN); Blair, James R. (Inver Grove Heights, MN)

1991-01-01

152

Valuing vaccination.  

PubMed

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

2014-08-26

153

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

154

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

155

Hard Determinism and the Moral "Ought"  

E-print Network

HARD DETERMINISM AND THE MORAL 'OUGHT' LENORE KUO The University of Nebraska at Omaha Philosophers from Aristotle to vanlnwagen 1 have questioned the possibility of preserving ethics if hard determinism is true. Thus it has been argued that we... must reject hard determinism because of the apparent "violence" it does to our basic conception of morality. For example, Howard Hintz maintains that: [Hard determinism) destroys the foundations of all prescriptive ethics except on the arbitrary...

Kuo, Lenore

156

Hardness analysis of cubic metal mononitrides from first principles  

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

157

Hard Cider Varieties Suitable for Northern  

E-print Network

Center #12;Hard Cider Planting at NWMHRC · Planted in 2001 and 2002 · First apples in fall 2004 ­ Most fermented 25 varieties #12;Hard Cider Apples · Cider apples are similar to wine grapes--their qualities are only noteworthy when made into wine or hard cider · Cider apples have flavor characteristics acquired

158

DISTRIBUTED VERIFICATION AND HARDNESS OF DISTRIBUTED APPROXIMATION  

E-print Network

DISTRIBUTED VERIFICATION AND HARDNESS OF DISTRIBUTED APPROXIMATION ATISH DAS SARMA, STEPHAN HOLZER on the hardness of distributed approximation for many classical optimization problems including minimum spanning the previous hardness of approximation bound of Elkin [STOC 2004] as well as the lower bound for (exact) MST

159

Distributed Verification and Hardness of Distributed Approximation  

E-print Network

Distributed Verification and Hardness of Distributed Approximation Atish Das Sarma Google Foundation (BSF). Permission to make digital or hard copies of all or part of this work for personal on the hardness of distributed approxi- mation for many classical optimization problems including minimum spanning

160

Empirical Hardness Models for Combinatorial Auctions  

E-print Network

Chapter 19 Empirical Hardness Models for Combinatorial Auctions Kevin Leyton-Brown, Eugene Nudelman and Yoav Shoham In this chapter we consider the empirical hardness of the winner determination problem. We to learn, evaluate and interpret a function from these features to the predicted hardness of an instance

Shoham, Yoav

161

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

162

Using Nondeterminism to Amplify Hardness Alexander Healy  

E-print Network

Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Division of Engineering revisit the problem of hardness amplification in NP, as recently studied by O'Donnell (JCSS `04). We prove to compute f on a 1/2 - 1/s (n) fraction of inputs. In particular, 1. If s(n) = n(1) , we amplify to hardness

Viola, Emanuele

163

Using Nondeterminism to Amplify Hardness Alexander Healy  

E-print Network

Using Nondeterminism to Amplify Hardness Alexander Healy Salil Vadhan Division of Engineering revisit the problem of hardness amplification in NP, as recently studied by O'Donnell (STOC `02). We prove to compute f on a 1/2 - 1/s (n) fraction of inputs. In particular, 1. If s(n) = n(1) , we amplify to hardness

Vadhan, Salil

164

Texts in Computational Complexity: Amplification of Hardness  

E-print Network

Texts in Computational Complexity: Amplification of Hardness Oded Goldreich Department of Computer a positive side, because hard problem can be ``put to work'' to our benefit, most notably in cryptography. One key issue that arises whenever one tries to utilize hard problem is bridging the gap between

Goldreich, Oded

165

Hard Metric from Cayley Graphs Yuri Rabinovich  

E-print Network

Hard Metric from Cayley Graphs Yuri Rabinovich Haifa University Joint work with Ilan Newman #12;Metric distortion and hard metrics The distortion of embedding a metric µ into an Euclidean space, c2(µ] and AR[98] claims that there exists metrics µ such that c2(µ)= (log n). We call such metrics hard. #12

Newman, Ilan

166

Hardness Amplification within NP against Deterministic Algorithms  

E-print Network

Hardness Amplification within NP against Deterministic Algorithms Parikshit Gopalan Microsoft Carnegie Mellon University. Abstract We study the average-case hardness of the class NP against algorithms these classes, namely we ask: How hard are languages in NP on average for deterministic polynomial time

Guruswami, Venkatesan

167

Input Locality and Hardness Amplification Andrej Bogdanov  

E-print Network

Input Locality and Hardness Amplification Andrej Bogdanov Alon Rosen Abstract We establish new hardness amplification results for one-way functions in which each input bit influences only a small number is injective then it is equally hard to invert f on a (1 - )-fraction of inputs. · If f is regular

Rosen, Alon

168

Kernelization hardness of connectivity problems Michal Pilipczuk  

E-print Network

Kernelization hardness of connectivity problems Michal Pilipczuk Faculty of Mathematics, Computer Science and Mechanics University of Warsaw 10th November 2010 Michal Pilipczuk Kernelization hardness of connectivity problems 1/13 #12;Source Kernelization hardness of connectivity problems in d-degenerate graphs WG

Fomin, Fedor V.

169

30 CFR 57.15002 - Hard hats.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Hard hats. 57.15002 Section 57.15002 Mineral...Surface and Underground § 57.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or plant where...

2012-07-01

170

30 CFR 57.15002 - Hard hats.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Hard hats. 57.15002 Section 57.15002 Mineral...Surface and Underground § 57.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or plant where...

2014-07-01

171

30 CFR 57.15002 - Hard hats.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Hard hats. 57.15002 Section 57.15002 Mineral...Surface and Underground § 57.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or plant where...

2013-07-01

172

30 CFR 56.15002 - Hard hats.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 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...

2012-07-01

173

30 CFR 57.15002 - Hard hats.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Hard hats. 57.15002 Section 57.15002 Mineral...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

174

30 CFR 56.15002 - Hard hats.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 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...

2011-07-01

175

30 CFR 56.15002 - Hard hats.  

Code of Federal Regulations, 2010 CFR

...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

176

30 CFR 56.15002 - Hard hats.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 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...

2014-07-01

177

30 CFR 56.15002 - Hard hats.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 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...

2013-07-01

178

30 CFR 57.15002 - Hard hats.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Hard hats. 57.15002 Section 57.15002 Mineral...Surface and Underground § 57.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or plant where...

2011-07-01

179

Decreased ventilatory function in hard metal workers  

Microsoft Academic Search

OBJECTIVES: To study individual effects on pulmonary function of exposure to hard metal including cobalt. METHODS: All of the workers in a hard metal company (583 men and 120 women) were examined for smoking, respiratory symptoms, ventilatory function, occupational history of exposure to hard metal, and present exposure to airborne cobalt. The ventilatory function indices (forced vital capacity (FVC), forced

Y Kusaka; M Iki; S Kumagai; S Goto

1996-01-01

180

Effect of the polishing technique at low or high speed on the micro-hardness of dental amalgam.  

PubMed

Dental cavities were prepared and restored with amalgam, using three different silver alloys. The surface of the restorations was finished 24 hours after condensation, with a rotatory instrument using a low- or high-speed handpiece. The specimens were then submitted to metallographic polishing and one of the margins of the amalgam restoration were then submitted to Vickers' micro-hardness test. Another micro-hardness test was accomplished 168 hours after condensation and the two sets of micro-hardness values were compared. No significant statistical differences were detected between the micro-hardness values obtained with low or high speed in the polishing technique. PMID:1819356

Pedigoni, M de L; Centola, A L; Froner, I C; Turbino, M L; Ribeiro, S A

1991-01-01

181

Model of hard spheroplatelets near a hard wall  

E-print Network

A system of hard spheroplatelets near an impenetrable wall is studied in the low-density Onsager approximation. Spheroplatelets have optimal shape between rods and plates, and the direct transition from the isotropic to biaxial nematic phase is present. A simple local approximation for the one-particle distribution function is used. Analytical results for the surface tension and the entropy contributions are derived. The density and the order-parameter profiles near the wall are calculated. The preferred orientation of the short molecule axes is perpendicular to the wall. Biaxiality close to the wall can appear only if the phase is biaxial in the bulk.

A. Kapanowski; M. Abram

2014-06-16

182

Hard Questions 1 When Hard Questions are Asked: Evaluating Writing Centers  

E-print Network

Hard Questions 1 When Hard Questions are Asked: Evaluating Writing Centers James H. Bell University of Northern British Columbia 3333 University Way Prince George, BC Canada V2N 4Z9 RUNNING HEAD: Hard Questions Reading and Learning. Thank you to three reviewers for their revision suggestions. #12;Hard Questions 2

Northern British Columbia, University of

183

Hardness Standardization Our objective is to standardize and improve hardness measurement  

E-print Network

Hardness Standardization METALS Our objective is to standardize and improve hardness measurement both in the U.S. and internationally. NIST is the U.S. National Metrology Institute (NMI) for hardness, and as such, is responsible for traceability in hardness measurements. Objective Impact and Customers

184

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 and hardness of dry snow layers for common grain types. These relations have been widely used to estimate), and to estimate the hardness of layers in snowpack evolution models. Since 2000, the database of snow layers has

Jamieson, Bruce

185

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

186

Estimation of Young's modulus and of hardness by ultra-low load hardness tests with a Vickers indenter  

SciTech Connect

The evaluation of the elastic-plastic properties of a material by using an ultra-low load hardness test requires a geometrical calibration that must take into account the imperfect form of the diamond indenter. In the present work, the Vickers indenter offset of the microindentation equipment was estimated using differently heat-treated steel samples. To this end, the dimensions of the indentations have been evaluated by two different methods: optical measurement of the diagonals and direct measurement of the penetration depth during the test. The elastic-plastic properties are then calculated from the analysis of the penetration depth/indentation load curves. The Young's modulus values determined for the different high-speed steel samples were very similar and close to the literature value for steel if the appropriate corrections are performed. The hardness values decrease when the determination procedure includes the geometrical correction of the indenter offset, and still further when using the total correction obtained by means of optical measurements of the indenter diagonal. Variation of the hardness values with the applied load is much less when the corrections are carried out.

Trindade, A.C. (Instituto Politecnico de Viseu (Portugal). Escola Superior de Tecnologia); Cavaleiro, A.; Fernandes, J.V. (Univ. de Coimbra (Portugal). Dept. de Engenharia Mecanica)

1994-07-01

187

Indentation Load Effect on Young's Modulus and Hardness of Porous Sialon Ceramic by Depth Sensing Indentation Tests  

NASA Astrophysics Data System (ADS)

Depth sensing indentation (DSI) tests at the range of 200-1800 mN are performed on porous sialon ceramic to determine the indentation load on Young's modulus and hardness values. The Young modulus and hardness (Dynamic and Martens) values are deduced by analysing the unloading segments of the DSI test load-displacement curves using the Oliver-Pharr method. It is found that Young's modulus Er, the dynamic hardness HD and the Martens hardness HM exhibit significant indentation load dependences. The values of Young's modulus and hardness decrease with the increasing indentation load, as a result of indentation load effect. The experimental hf/hm ratios lower than the critical value 0.7, with hm being the maximum penetration depth during loading and hf the final unloading depth, indicate that our sample shows the work hardening behaviour.

Osman, Sahin

2007-11-01

188

The maximum hardness principle implies the hard\\/soft acid\\/base rule  

Microsoft Academic Search

A recent paper [P. W. Ayers, J. Chem. Phys122, 141102 (2005)] considered the hard\\/soft acid\\/base exchange reaction, showing that the products associated with the hard\\/soft acid\\/base rule (in which the hard acid and hard base are bound, as are the soft acid and soft base) have lower energy than the alternative (in which the hard acid and soft base would

Pratim K. Chattaraj; Paul W. Ayers

2005-01-01

189

The hard problem of cooperation.  

PubMed

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

190

Hard Core entropy: lower bounds  

E-print Network

We establish lower bounds for the entropy of the Hard Core Model on a few 2d lattices $\\scriptstyle {\\rm {\\bf L}}.$ In this model the allowed configurations inside $\\scriptstyle \\{0,1\\}^{{\\rm {\\bf L}}}$ are the one's in which the nearest neighbor $\\scriptstyle 1$'s are forbidden. Our method which is based on a sequential fill-in scheme is unbiassed and thereby yields in principle arbitrarily good estimates for the topological entropy. The procedure also gives some detailed information on the support of the measure of maximal entropy.

Kari Eloranta

2009-09-22

191

Making Nozzles From Hard Materials  

NASA Technical Reports Server (NTRS)

Proposed method of electrical-discharge machining (EDM) cuts hard materials like silicon carbide into smoothly contoured parts. Concept developed for fabrication of interior and exterior surfaces and internal cooling channels of convergent/divergent nozzles. EDM wire at skew angle theta creates hyperboloidal cavity in tube. Wire offset from axis of tube and from axis of rotation by distance equal to throat radius. Maintaining same skew angle as that used to cut hyperboloidal inner surface but using larger offset, cooling channel cut in material near inner hyperboloidal surface.

Wells, Dennis L.

1989-01-01

192

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

193

Hardness and Young's modulus of human peritubular and intertubular dentine.  

PubMed

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 of fully hydrated intertubular dentine did depend upon location, and was significantly greater near the dentine enamel junction (values ranged from 0.49 to 0.52 GPa) than near the pulp (0.12-0.18 GPa). A Nanoindenter was used to estimate the Young's modulus of dehydrated peritubular and intertubular dentine from the unloading portion of the load displacement curve. The modulus values averaged 29.8 GPa for the peritubular dentine (considered to be a lower limit), and ranged from 17.7 to 21.1 GPa for the intertubular dentine, with the lower values obtained for dentine near the pulp. PMID:8833584

Kinney, J H; Balooch, M; Marshall, S J; Marshall, G W; Weihs, T P

1996-01-01

194

Value Stream Mapping Value Stream Mapping VSM  

E-print Network

Value Stream Mapping (VSM)(VSM) #12;Value Stream Mapping VSM 1 Value Stream Mapping VSM 1 Value Stream Current State Map As-Is State / - Process owner - Process owner #12) #12;Value Stream MappingValue Stream Mapping End to End Patient Flow Register OPD/ER Admit Dischargeg

Laksanacharoen, Sathaporn

195

Kinetics of hardness evolution during annealing of gamma-irradiated polycarbonate  

SciTech Connect

This study focuses on the evolution in microhardness values that accompany isothermal annealing in gamma-irradiated polycarbonate (PC). Hardness increases with increasing annealing time, temperature, and gamma radiation dose. A model composed of a mixture of first and zero order structure relaxation is proposed to interpret the hardness data. The rate constant data fit the Arrhenius equation, and the corresponding activation energy decreases with increasing dose. The extent of structural relaxation that controls the hardness in post-annealed PC increases with increasing annealing temperature and dose. The model demonstrates that hardness evolution in PC is an endothermic process. By contrast, when the model is applied to irradiated poly(methyl methacrylate) and hydroxyethyl methacrylate copolymer, hardness evolution is an exothermic process.

Yeh, S. H.; Chen, P. Y.; Lee, Sanboh [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Harmon, Julie [Department of Chemistry, University of South Florida, Tampa, Florida 33620-5250 (United States)

2012-12-01

196

Physics with Trapped Charged Particles Martina Knoop1  

E-print Network

by a brief account of some of the current applications of ion traps. 1.1.Introduction When Wolfgang Paul introduced at about the same time. Wolfgang Paul and his group in Bonn developed the three-dimensional Paul The two main types of ion trap (the Paul, or radiofrequency, trap and the Penning trap) were both

Paris-Sud XI, Université de

197

Predicting the Performance of Chain Saw Machines Based on Shore Scleroscope Hardness  

NASA Astrophysics Data System (ADS)

Shore hardness has been used to estimate several physical and mechanical properties of rocks over the last few decades. However, the number of researches correlating Shore hardness with rock cutting performance is quite limited. Also, rather limited researches have been carried out on predicting the performance of chain saw machines. This study differs from the previous investigations in the way that Shore hardness values (SH1, SH2, and deformation coefficient) are used to determine the field performance of chain saw machines. The measured Shore hardness values are correlated with the physical and mechanical properties of natural stone samples, cutting parameters (normal force, cutting force, and specific energy) obtained from linear cutting tests in unrelieved cutting mode, and areal net cutting rate of chain saw machines. Two empirical models developed previously are improved for the prediction of the areal net cutting rate of chain saw machines. The first model is based on a revised chain saw penetration index, which uses SH1, machine weight, and useful arm cutting depth as predictors. The second model is based on the power consumed for only cutting the stone, arm thickness, and specific energy as a function of the deformation coefficient. While cutting force has a strong relationship with Shore hardness values, the normal force has a weak or moderate correlation. Uniaxial compressive strength, Cerchar abrasivity index, and density can also be predicted by Shore hardness values.

Tumac, Deniz

2014-03-01

198

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

199

Universit Libre de Bruxelles Exclusive (hard) diffraction  

E-print Network

1 P. Marage Université Libre de Bruxelles Exclusive (hard) diffraction at HERA (DVCS and Vector) - photoprod. ZEUS DESY-09-036 - real at large |t| H1 DESY-08-077 e e * p Y VM Q2 t W P. Marage Exclusive hard 2 2 ( )/4Q M Marage Exclusive hard diffraction at HERA (DVCS and VM) EDS'09 ­ CERN 29

200

Theory of Hard Diffraction and Rapidity Gaps  

E-print Network

In this talk we review the models describing the hard diffractive production of jets or more generally high-mass states in presence of rapidity gaps in hadron-hadron and lepton-hadron collisions. By rapidity gaps we mean regions on the lego plot in (pseudo)-rapidity and azimuthal angle where no hadrons are produced, between the jet(s) and an elastically scattered hadron (single hard diffraction) or between two jets (double hard diffraction).

Vittorio Del Duca

1995-06-18

201

Hard-gapped Holographic Superconductors  

E-print Network

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

Pallab Basu; Jianyang He; Anindya Mukherjee; Hsien-Hang Shieh

2009-12-05

202

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

203

Effects of fast halogen and plasma arc curing lights on the surface hardness of orthodontic adhesives for lingual retainers  

Microsoft Academic Search

The aims of this study were to (1) identify the optimum cure times of 2 different lingual retainer adhesives with a conventional halogen, a fast halogen, and a plasma arc light by measuring Vickers surface hardness, and (2) determine whether different lights produce similar surface hardness values for the same adhesive resin material. The investigated plasma arc curing unit was

Serdar Ü?ümez; Tamer Büyüky?lmaz; Ali Ihya Karaman

2003-01-01

204

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.

205

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

206

HARDNESS RESULTS FOR CAKE CUTTING Costas Busch Mukkai S. Krishnamoorthy Malik Magdon-Ismail  

E-print Network

HARDNESS RESULTS FOR CAKE CUTTING Costas Busch Mukkai S. Krishnamoorthy Malik Magdon,moorthy,magdon}@cs.rpi.edu Abstract Fair cake-cutting is the division of a cake or resource among N users so that each user is content. Users may value a given piece of cake differently, and information about how a user values different

Busch, Konstantin "Costas"

207

Prediction of a Structural Transition in the Hard Disk Fluid  

E-print Network

Starting from the second equilibrium equation in the BBGKY hierarchy under the Kirkwood superposition closure, we implement a new method for studying the asymptotic decay of correlations in the hard disk fluid in the high density regime. From our analysis and complementary numerical studies, we find that exponentially damped oscillations can occur only up to a packing fraction {\\eta}*~0.718, a value which is in substantial agreement with the packing fraction, {\\eta}~0.723, believed to characterize the transition from the ordered solid phase to a dense fluid phase, as inferred from Mak's Monte Carlo simulations [Phys. Rev. E 73, 065104 (2006)]. We next show that the same method of analysis predicts that exponential damping of oscillations in the hard sphere fluid becomes impossible when \\lambda = 4n\\pi {\\sigma}^3 [1 + H(1)]>/- 34.81, where H(1) is the contact value of the correlation function, n is the number density and {\\sigma} is the sphere diameter, in exact agreement with the condition, \\lambda >/- 34.8, first reported in a numerical study of the Kirkwood equation by Kirkwood et al. [J. Chem. Phys. 18, 1040 (1950)]. Finally, we show that our method confirms the absence of any structural transition in hard rods for the entire range of densities below close packing.

Jaroslaw Piasecki; Piotr Szymczak; John J. Kozak

2010-09-16

208

Hard-sphere fluid: new exact results with applications  

SciTech Connect

A theorem for convolution integrals is proved and then applied to extend the second zero-separation theorem to the bridge function b(r) and direct-correlation tail functions d(r). This theorem allows us to exactly relate deltab(r)/deltar and deltad(r)/deltar at r = 0 for the hard-sphere fluid to the contact values of the radial distribution function g(r) at r = sigma/sup +/. From this we obtain immediately the exact values of deltab(r)/deltar and deltad(r)/deltar at r = 0 through second order in number density rho. Using our results to compare the exact and Percus-Yevick (PY) bridge function, we find that they differ significantly. After obtaining the bridge function and tail function and their derivatives at r = 0 and r = sigma through, we suggest new approximations for b(0) and d(0) as well as an analytical integral-equation theory to improve the PY approximation in the pure hard-sphere fluid. The major deficiency of that approximation has been its poor assessment of the cavity function inside the hard-core region. Our theory remedies this defect is a way that yields a y(r) that is self-consistent with respect to the virial and compressibility relations and also the two zero-separation relations involving y(r) and its spatial derivative at r = 0.

Zhou, Y.; Stell, G.

1988-09-01

209

Relationship between kernel color and protein content of hard red x hard white winter wheat progeny  

Microsoft Academic Search

Utilization of high-protein hard red wheat germplasm in breeding high-protein hard white winter wheats for the U.S. Great Plains raised concern regarding possible genetic relationships between kernel color and protein content. Segregating F3 and F4 populations from reciprocal crosses and backcrosses involving high-protein hard red winter wheat cultivar Plainsman V and normal-protein hard white winter wheat line KS75216 were examined.

L. M. Corpuz; G. M. Paulsen; E. G. Heyne

1983-01-01

210

Magnetic viscosity studies in hard magnetic materials  

SciTech Connect

The magnetic viscosity behavior has been studied in several hard magnets with different magnetization reversal mechanisms including barium ferrite powders, Cu-Mn-Al, ferrite magnets, Nd-Fe-B, and SmCo{sub 5}, Sm{sub 2}(Co,Fe,Cu,Zr){sub 17}. The measurements were made with a vibrating sample magnetometer for times up to 60 s and a SQUID magnetometer for longer times in the range of 60--2300 s. For most of the samples the magnetization was found to vary logarithmically with time. The field and temperature dependence of the magnetic viscosity coefficient {ital S} was studied. Here, {ital S} was found to vary with the applied field and it usually peaked around the coercive field {ital H}{sub {ital c}}. The measured values of {ital S}{sub max} at 10 K range from 0.004 to 1.853 emu/g for Cu-Mn-Al and Sm{sub 2}(Co,Fe,Cu,Zr){sub 17}, respectively. The magnetic viscosity coefficient was used together with the magnetic susceptibility to determine the activation volume.

Singleton, E.W.; Hadjipanayis, G.C. (Department of Physics, Cardwell Hall, Kansas State University, Manhattan, Kansas 66506 (USA))

1990-05-01

211

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

2009-01-09

212

Hard X-ray Radiation in the Coma Cluster  

NASA Astrophysics Data System (ADS)

Hard X-ray radiation has been detected for the first time in the Coma cluster spectrum, during the AO-1 observations. Thanks to the unprecedented sensitivity of the Phoswich Detection System (PDS) onboard the Beppo-SAX observatory, the source has been detected up to ~80 keV. There is clear evidence for non-thermal emission in excess to the thermal one above ~25 keV at a 4.5 sigma level. Our analysis is able to exclude that the hard excess may be due to X Comae, a type I Seyfert galaxy present in the FOV of the PDS. A volume-averaged intracluster magnetic field of 0.16 mu G is derived, in order to account for the observed syncrotron radio emission. This value is in contrast with the estimates based on Faraday rotation measurements seen through the hot intracluster medium of the Coma Cluster.

Fusco-Femiano, R.; dal Fiume, D.; Feretti, L.; Giovannini, G.; Matt, G.; Molendi, S.

1998-12-01

213

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

214

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.

215

Practical hardness scales for metal ion complexes  

Microsoft Academic Search

Experimentally determined log stability constant differences for substitution reactions of one ligand for another on a metal ion are used to derive practical metal ion hardness–softness scales applicable to aqueous solutions. These scales probably correspond to what most investigators imply when they use the terms hardness and softness. The correlation between the halide scale for fluoride minus bromide and the

R. Bruce Martin

2002-01-01

216

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

217

Industrial applications of PACVD hard coatings  

Microsoft Academic Search

Transition metal nitride based hard coatings are widely applied in metal cutting, however, there are still drawbacks in metal forming processes limiting their implementation. The aim of this study is thus to discuss deposition processes suitable for coating of the often large and three-dimensional molds and dies used in metal forming. Furthermore, results obtained using different hard coatings in industrial

C Mitterer; F Holler; D Reitberger; E Badisch; M Stoiber; C Lugmair; R Nöbauer; Th Müller; R Kullmer

2003-01-01

218

Hard Homogeneous Spaces Jean-Marc Couveignes  

E-print Network

be, I will publish an updated version later. We introduce the notion of hard homogeneous space (HHS that the concept of HHS fits with class field theory to provide a unified theory for the already used discrete) and the HHS we present here. We discuss a few algorithmic questions related to hard homogeneous spaces

219

Hard Homogeneous Spaces JeanMarc Couveignes  

E-print Network

be, I will publish an updated version later. We introduce the notion of hard homogeneous space (HHS that the concept of HHS fits with class field theory to provide a unified theory for the already used discrete) and the HHS we present here. We discuss a few algorithmic questions related to hard homogeneous spaces

220

HARD RED SPRING WHEAT - 2001 CROP  

Technology Transfer Automated Retrieval System (TEKTRAN)

The USDA/ARS Hard Red Spring and Durum Wheat Quality Laboratory evaluated 16 cultivars of hard red spring (HRS) wheat from the 2001 crop for kernel and milling properties, and subsequently shipped flour (and/or wheat) to overseas cooperators through arrangements made by US Wheat Associates (USW) for...

221

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

222

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

223

Monte Carlo computer simulation of sedimentation of charged hard spherocylinders  

NASA Astrophysics Data System (ADS)

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?)/(e2/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.

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

2014-07-01

224

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

225

Phase Diagram of Hard Tetrahedra  

E-print Network

Advancements in the synthesis of faceted nanoparticles and colloids have spurred interest in the phase behavior of polyhedral shapes. Regular tetrahedra have attracted particular attention because they prefer local symmetries that are incompatible with periodicity. Two dense phases of regular tetrahedra have been reported recently. The densest known tetrahedron packing is achieved in a crystal of triangular bipyramids (dimers) with packing density 4000/4671=85.63%. In simulation a dodecagonal quasicrystal is observed; its approximant, with periodic tiling (3.4.3^2.4), can be compressed to a packing fraction of 85.03%. Here, we show that the quasicrystal approximant is more stable than the dimer crystal for packing densities below 84% using Monte Carlo computer simulations and free energy calculations. To carry out the free energy calculations, we use a variation of the Frenkel-Ladd method for anisotropic shapes and thermodynamic integration. The enhanced stability of the approximant can be attributed to a network substructure, which maximizes the free volume (and hence the 'wiggle room') available to the particles and facilitates correlated motion of particles, which further contributes to entropy and leads to diffusion for packing densities below 65%. The existence of a solid-solid transition between structurally distinct phases not related by symmetry breaking -- the approximant and the dimer crystal-- is unusual for hard particle systems.

Amir Haji-Akbari; Michael Engel; Sharon C. Glotzer

2011-11-22

226

Hardness measurements of Ar[sup +]-beam treated polyimide by depth-sensing ultra low load indentation  

SciTech Connect

Polyimide Kapton and spin-cast polyamic acid (PAA) on sapphire have been implanted with 1 MeV Ar ions to a dose of 4.7[times]10[sup 15] cm[sup [minus]2] at ambient temperature. The properties of both pristine and implanted surfaces were characterized by a depth-sensing low-load indentation technique. Experiments were carried out to investigate the effects of substrate, indentation rate, relaxation, and indentation technique. The results showed that (1) hardness was depth-dependent and decreased with increasing indentation depth, (2) measurements of the ion beam hardened surface with the untreated material as a substrate underestimated the hardness while measurements over the sapphire substrate overestimated it, (3) the effects of loading/unloading rates were apparent in the load displacement results, and (4) hardness values measured using the force modulation technique showed very little depth dependence. The hardness value at 100 nm depth is used for comparison purposes since the hardness value at this depth was almost independent of substrate, indentation rate, and indentation method. The hardness of Kapton, which was measured using the techniques described herein, was increased by over 30 times after Ar implantation, from 0.43 to 13 GPa at 100 nm indentation depth. A similar increase in hardness was also observed for polyamic acid. This result suggests that spin-cast PAA film may have potential technological applications for protective coatings where hardness and wear resistance are required.

Lee, E.H.; Lee, Y.; Oliver, W.C.; Mansur, L.K. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States))

1993-02-01

227

Hard Choices for Individual Situations.  

ERIC Educational Resources Information Center

This paper focuses on faculty use of a decision-making process for complex situations. The analysis part of the process describes and compares course management software focusing on: technical specifications, instructional design values,tools and features, ease of use, and standards compliance. The extensive comparisons provide faculty with…

Landon, Bruce

228

Exclusive, Hard Diffraction in QCD  

E-print Network

In the first chapter we give an introduction to hard diffractive scattering in QCD to introduce basic concepts and terminology. In the second chapter we make predictions for the evolution of skewed parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA and solve the skewed GLAP evolution equations with a modified version of the CTEQ-package. In the third chapter, we discuss the algorithms used in the LO evolution program for skewed parton distributions in the DGLAP region, discuss the stability of the code and reproduce the LO diagonal evolution within less than 0.5% of the original CTEQ-code. In chapter 4, we show that factorization holds for the deeply virtual Compton scattering amplitude in QCD, up to power suppressed terms, to all orders in perturbation theory. In chapter 5, we demonstrate that perturbative QCD allows one to calculate the absolute cross section of diffractive, exclusive production of photons (DVCS) at large $Q^2$ at HERA, while the aligned jet model allows one to estimate the cross section for intermediate $Q^2 \\sim 2 GeV^2$. We find a significant DVCS counting rate for the current generation of experiments at HERA and a large azimuthal angle asymmetry for HERA kinematics. In the last chapter, we propose a new methodology of gaining shape fits to skewed parton distributions and, for the first time, to determine the ratio of the real to imaginary part of the DIS amplitude. We do this by using several recent fits to $F_2(x,Q^2)$ to compute the asymmetry $A$ for the combined DVCS and Bethe-Heitler cross section. In the appendix, we give an application of distributional methods as discussed abstractly in chapter 4.

Andreas Freund

1999-03-05

229

Effects of water hardness on the toxicity of manganese to developing brown trout (Salmo trutta)  

SciTech Connect

Manganese is a common constituent of point and nonpoint discharges from mining and smelting activities. Available data indicate that Mn is acutely toxic at relatively high aqueous concentrations, when compared with trace metals, and its toxicity is affected by water hardness. Little information is available regarding the chronic toxicity of manganese. Early-life-stage (ELS) tests were conducted to determine the toxicity of manganese to brown trout (Salmo trutta) and to evaluate the extent to which water hardness (ranging from 30 to 450 mg/L as CaCO{sub 3}) affects the chronic toxicity of Mn. Water hardness of significantly affected Mn chronic toxicity, with toxicity decreasing with increasing hardness. Decreased survival was the predominant effect noted in the 30-mg/L hardness experiment, while significant effects on growth (as measured by changes in body weight) were observed in both the 150- and 450-mg/L hardness experiments. Twenty-five percent inhibition concentration (IC25) values, based on the combined endpoints (i.e., survival and body weight), were 4.67, 5.59, and 8.68 mg Mn/L (based on measured Mn concentration) at hardness levels of approximately 30, 150, and 450 mg/L as CaCO{sub 3}, respectively.

Stubblefield, W.A.; Garrison, T.D.; Hockett, J.R. [ENSR Corp., Fort Collins, CO (United States); Brinkman, S.F.; Davies, P.H.; McIntyre, M.W. [Colorado Div. of Wildlife, Fort Collins, CO (United States)

1997-10-01

230

Theory of hard diffraction and rapidity gaps  

SciTech Connect

In this talk we review the models describing the hard diffractive production of jets or more generally high-mass states in presence of rapidity gaps in hadron-hadron and lepton-hadron collisions. By rapidity gaps we mean regions on the lego plot in (pseudo)-rapidity and azimuthal angle where no hadrons are produced, between the jet(s) and an elastically scattered hadron (single hard diffraction) or between two jets (double hard diffraction). {copyright} {ital 1996 American Institute of Physics.}

Del Duca, V. [Deutsches Elektronen-Synchrotron DESY, D-22603 Hamburg (Germany)

1996-02-01

231

NNLO hard functions in massless QCD  

E-print Network

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.

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

2014-09-18

232

Analysis of Hard Thin Film Coating  

NASA Technical Reports Server (NTRS)

Marshall Space Flight Center (MSFC) is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using Electron Cyclotron Resonance Chemical Vapor Deposition (ECRCVD) to deposit hard thin film on stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

Shen, Dashen

1998-01-01

233

Analysis of Hard Thin Film Coating  

NASA Technical Reports Server (NTRS)

MSFC is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using electron cyclotron resonance chemical vapor deposition (ECRCVD) to deposit hard thin film an stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

Shen, Dashen

1998-01-01

234

Shape Deformation of Vesicles Containing Hard Spheres  

NASA Astrophysics Data System (ADS)

Vesicles containing charged colloids show peculiar shape deformation under certain conditions. However, its physical mechanism is not clear. We have performed Monte Carlo simulation for a model of closed triangulated membrane and encapsulated hard spheres. We analyzed vesicular shapes and encapsulated hard spheres by using diffusion coefficient, change of area difference and volume, and the radial distribution of hard spheres from the membrane. The discussion of our results can be used as the foundation for understanding of the complex behavior of vesicles containing colloids.

Itoga, Hibiki; Morikawa, Ryota; Miyakawa, Takeshi; Yamada, Hironao; Natsume, Yuno; Ueta, Tsuyoshi; Takasu, Masako

235

Genetic analysis of grain protein content, grain hardness and dough rheology in a hard×hard bread wheat progeny  

Microsoft Academic Search

Kernel texture (hard vs soft grain) and more subtle within-class variations are known to have a large influence on end-use properties, mostly through the proportion of damaged starch and subsequent water requirement. In this study, quantitative trait loci (QTL) affecting kernel texture and dough rheology in a progeny from a cross between two ‘medium-hard’ wheat cultivars were identified and compared

C. Groos; E. Bervas; G. Charmet

2004-01-01

236

Hard and Soft Constraints in Reliability-Based Design Optimization  

NASA Technical Reports Server (NTRS)

This paper proposes a framework for the analysis and design optimization of models subject to parametric uncertainty where design requirements in the form of inequality constraints are present. Emphasis is given to uncertainty models prescribed by norm bounded perturbations from a nominal parameter value and by sets of componentwise bounded uncertain variables. These models, which often arise in engineering problems, allow for a sharp mathematical manipulation. Constraints can be implemented in the hard sense, i.e., constraints must be satisfied for all parameter realizations in the uncertainty model, and in the soft sense, i.e., constraints can be violated by some realizations of the uncertain parameter. In regard to hard constraints, this methodology allows (i) to determine if a hard constraint can be satisfied for a given uncertainty model and constraint structure, (ii) to generate conclusive, formally verifiable reliability assessments that allow for unprejudiced comparisons of competing design alternatives and (iii) to identify the critical combination of uncertain parameters leading to constraint violations. In regard to soft constraints, the methodology allows the designer (i) to use probabilistic uncertainty models, (ii) to calculate upper bounds to the probability of constraint violation, and (iii) to efficiently estimate failure probabilities via a hybrid method. This method integrates the upper bounds, for which closed form expressions are derived, along with conditional sampling. In addition, an l(sub infinity) formulation for the efficient manipulation of hyper-rectangular sets is also proposed.

Crespo, L.uis G.; Giesy, Daniel P.; Kenny, Sean P.

2006-01-01

237

Investigation Of Tool Wear In Hard Turning Using Taguchi Method  

NASA Astrophysics Data System (ADS)

Hard turning is a machining process defined of hardness higher than 45 HRC under appropriate cutting tools and cutting speed. The objective of this paper is to investigate the optimum process parameters for a particular work piece-tool material combination. . In this study, three levels of each parameters viz. Hardness (HRC), Speed(mm/min), Feed(mm/rev) and three different tool materials are evaluated for process quality characteristics such as tool wear. The three different tool materials used are High CBN, Low CBN, Mixed ceramic. AISI H 11 was taken as work piece material. The experiment is designed using Taguchi Method. The results obtained from the experiments are transformed into signal to noise (S/N) ratio and used to optimize the value of tool wear. The analysis of variance (ANOVA) is performed to indentify the statistical significance of parameters. The final results of experimental investigation are presented in this paper. The conclusions arrived at are critically discussed at the end.

Chaudhari, Y. D.

2013-03-01

238

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 Design ApS #12;Horns Rev. Hard Bottom Substrate Monitoring Page 3 Annual Status Report 2003 Doc. No. 2230

239

Bulk and wetting phenomena in a colloidal mixture of hard spheres and platelets  

E-print Network

Density functional theory is used to study binary colloidal fluids consisting of hard spheres and thin platelets in their bulk and near a planar hard wall. This system exhibits liquid-liquid coexistence of a phase that is rich in spheres (poor in platelets) and a phase that is poor in spheres (rich in platelets). For the mixture near a planar hard wall, we find that the phase rich in spheres wets the wall completely upon approaching the liquid demixing binodal from the sphere-poor phase, provided the concentration of the platelets is smaller than a threshold value which marks a first-order wetting transition at coexistence. No layering transitions are found in contrast to recent studies on binary mixtures of spheres and non-adsorbing polymers or thin hard rods.

L. Harnau; S. Dietrich

2004-08-27

240

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

241

Radiation hardness of polysulphone and polycarbonate elements for LHC detectors  

E-print Network

In the TRT Inner Detector being developed for ATLAS, elements made from plastic materials are widely used. In order to meet necessary requirements of the construction, these materials should have a high radiation hardness. This work presents a study of mechanical features of polysulphone and polycarbonate in dependence on the radiation dose. The results of measurements have shown a weak dependence of mechanical properties of polysulphone and polycarbonate on the absorbed dose up to the value of 1 MGy. So, the products from these materials could be used to construct detectors at LHC, at least on the mechanical point of view.

Hauviller, Claude; Bychkov, V; Golikov, V V; Kekelidze, G D; Lobastov, S P; Luschikov, V I; Peshekhonov, V D

1998-01-01

242

From Value Chain to Value Network  

Microsoft Academic Search

The concept of a value chain has assumed a dominant position in the strategic analysis of industries. However, the value chain is underpinned by a particular value creating logic and its application results in particular strategic postures. Adopting a network perspective provides an alternative perspective that is more suited to New Economy organisations, particularly for those where both the product

Anna Rylander

2006-01-01

243

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

244

Defects in hard-sphere colloidal crystals  

NASA Astrophysics Data System (ADS)

Colloidal crystals of 1.55 microm diameter silica particles were grown on {100} and flat templates by sedimentation and centrifugation. The particles interact as hard spheres. The vacancies and divacancies in these crystals are not in equilibrium, since no movement of single vacancies is observed. The lack of mobility is consistent with the extrapolation of earlier simulations at lower densities. The volume of relaxation of the vacancy has a plausible value for these densities as the volume of formation is approaching the volume in a close-packed crystal. The volume of relaxation for the divacancy is smaller than that of two vacancies, so that the association of two vacancies into a divacancy requires extra volume, and hence extra entropy. The mean square displacement of the nearest neighbors of the vacancies is an order of magnitude larger than that of the nearest neighbors of particles. The mobility of the divacancies is consistent with the extrapolation of older simulations and is similar to that associated with the annihilation of the vacancy-interstitial pair. The volume of motion of the divacancies is DeltaVm = 0.19Vo (Vo: close-packed volume) and the entropy of motion is DeltaSm = 0.49kBT. Dislocation-twin boundary interactions can be observed by introducing strain via a misfit template. The dislocations formed are Shockley partials. When a dislocation goes through the boundary, two more dislocations are created: a reflected dislocation and one left at the boundary, both with the same magnitude Burgers vector. The dislocations relieve a total of about a third of the misfit strain. The remaining strain is sufficiently large to move the dislocation up to the boundary and close to sufficient to move the dislocation through the boundary. A small amount to extra strain energy is needed to cause nucleation of the two additional dislocations after a waiting time.

Persson Gulda, Maria Christina Margareta

245

One-dimensional gas of hard needles  

E-print Network

We study a one-dimensional gas of needlelike objects as a testing ground for a formalism that relates the thermodynamic properties of “hard” potentials to the probabilities for contacts between particles. Specifically, we ...

Kardar, Mehran

246

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2011 CFR

...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

247

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2012 CFR

...ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act...hard seed.” If at the end of the germination period provided for legumes...seedlings included in the percentage of germination. For flatpea, continue the...

2012-01-01

248

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2010 CFR

...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,...

2010-01-01

249

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2014 CFR

...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

250

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2013 CFR

...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

251

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2014 CFR

...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

252

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2010 CFR

...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,...

2010-01-01

253

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2011 CFR

...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

254

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2013 CFR

...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

255

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2013 CFR

...ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act...hard seed.” If at the end of the germination period provided for legumes...seedlings included in the percentage of germination. For flatpea, continue the...

2013-01-01

256

7 CFR 201.30 - Hard seed.  

Code of Federal Regulations, 2012 CFR

...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

257

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2014 CFR

...ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act...hard seed.” If at the end of the germination period provided for legumes...seedlings included in the percentage of germination. For flatpea, continue the...

2014-01-01

258

7 CFR 201.21 - Hard seed.  

Code of Federal Regulations, 2012 CFR

...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

259

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2011 CFR

...ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act...hard seed.” If at the end of the germination period provided for legumes...seedlings included in the percentage of germination. For flatpea, continue the...

2011-01-01

260

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

261

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

262

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

E-print Network

In the preceding paper (cond-mat/0405252), we have conjectured that the main transport properties of a dilute gas of inelastic hard spheres (IHS) can be satisfactorily captured by an equivalent gas of elastic hard spheres (EHS), provided that the latter are under the action of an effective drag force and their collision rate is reduced by a factor $(1+\\alpha)/2$ (where $\\alpha$ is the constant coefficient of normal restitution). In this paper we test the above expectation in a paradigmatic nonequilibrium state, namely the simple or uniform shear flow, by performing Monte Carlo computer simulations of the Boltzmann equation for both classes of dissipative gases with a dissipation range $0.5\\leq \\alpha\\leq 0.95$ and two values of the imposed shear rate $a$. The distortion of the steady-state velocity distribution from the local equilibrium state is measured by the shear stress, the normal stress differences, the cooling rate, the fourth and sixth cumulants, and the shape of the distribution itself. In particular, the simulation results seem to be consistent with an exponential overpopulation of the high-velocity tail. The EHS results are in general hardly distinguishable from the IHS ones if $\\alpha\\gtrsim 0.7$, so that the distinct signature of the IHS gas (higher anisotropy and overpopulation) only manifests itself at relatively high dissipations

A. Astillero; A. Santos

2005-08-30

263

Short-hard gamma-ray bursts  

Microsoft Academic Search

Two types of gamma-ray bursts (GRBs) are observed: short-duration hard spectrum GRBs and long-duration soft spectrum GRBs. For many years long GRBs were the focus of intense research while the lack of observational data limited the study of short-hard GRBs (SHBs). In 2005 a breakthrough occurred following the first detections of SHB afterglows, longer wavelength emission that follows the burst

Ehud Nakar

2007-01-01

264

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.

265

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

266

A Novel Approach to Hardness Testing  

NASA Technical Reports Server (NTRS)

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

Spiegel, F. Xavier; West, Harvey A.

1996-01-01

267

The hard pomeron in soft data  

NASA Astrophysics Data System (ADS)

We show that the data for the total cross section and for the real part of the elastic amplitude indicate the presence of a hard pomeron in ?p and Kp elastic scattering at t=0, compatible with that observed in deep inelastic scattering. We show that such a hard pomeron is also compatible with pp and p¯p data, provided one unitarises it at high energy.

Cudell, J. R.; Martynov, E.; Selyugin, O.; Lengyel, A.

2004-05-01

268

Laboratory studies of hard rock for CAES  

NASA Astrophysics Data System (ADS)

The properties of hard rock specimens, from formations suitable for compressed air energy storage (CAES) that are subject to the conditions envisioned for a CAES cavern, were investigated by means of laboratory testing. It was concluded that although the compressive and tensile strengths are adversely influenced by a CAES cavern environment, the reduced failure strength of hard rocks is sufficiently high to indicate that a CAES plant could be operated satisfactorily.

Fossum, A. F.

1980-10-01

269

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.

2014-01-01

270

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

271

Equations of state for hard-sphere fluids  

SciTech Connect

Equations of state and contact values of hard-sphere radial distribution functions (rdf's) which are given by a linear combination of the Percus-Yevick and scaled-particle virial expressions are considered. In the one-component case the mixing coefficient /theta/(/eta/)is, in general a function of the volume fraction /eta/. In mixtures the coefficient /theta/(/eta//sub i/, d/sub i/), in general, depends upon the volume fraction /eta//sub i/ and diameter d/sub i/ of each species, i and j. For the contact values Y/sub ij/ of the rdf's, the mixing coefficients /Theta//sub ij/(/eta//sub k/) also depend on species i and j. Density expansions for the exact /theta/ for the one-component hard-sphere fluid are obtained and compared with several approximations made in earlier works and in the authors own work, as well as with simulation. For a mixture, it turns out that one cannot obtain the exact fourth virial coefficient by using a linear combination of the Percus-Yevick and scaled-particle virial expression for Y/sub ij/ unless one allows /Theta//sub ij/ to depend on mole fractions x/sub i/ even at the zeroth order of its density expansion. They also find that /Theta//sub ij/ must depend on particle species i and j in order to satisfy the exact limits obtained earlier by Sung and Stell. A new equation of state for the binary hard-sphere mixture which satisfies all the exact limits they have considered is suggested.

Zhou, Y.; Stell, G.

1988-11-01

272

Hard evidence on soft skills?  

PubMed Central

This paper summarizes recent evidence on what achievement tests measure; how achievement tests relate to other measures of “cognitive ability” like IQ and grades; the important skills that achievement tests miss or mismeasure, and how much these skills matter in life. Achievement tests miss, or perhaps more accurately, do not adequately capture, soft skills—personality traits, goals, motivations, and preferences that are valued in the labor market, in school, and in many other domains. The larger message of this paper is that soft skills predict success in life, that they causally produce that success, and that programs that enhance soft skills have an important place in an effective portfolio of public policies. PMID:23559694

Heckman, James J.; Kautz, Tim

2012-01-01

273

Orientational ordering of hard zigzag needles in one dimension  

NASA Astrophysics Data System (ADS)

The orientational ordering and the tilt angle behavior of a one-dimensional fluid of hard zigzag needles are examined by means of transfer matrix method and Onsager theory. The centers of mass of the particles are restricted to a line, while the orientational unit vectors are allowed to rotate freely in two dimensions. It is shown that zigzag needles do not undergo an isotropic-nematic phase transition, but the system is always in an orientationally ordered phase where the order parameter increases with the density. For hard needles and any other kinds of particles with an axis of symmetry the orientational distribution function is symmetric around its maximum value and the nematic director is perpendicular to the layer. For zigzag needles, which have nonconvex shape without an axis of symmetry, the orientational order is anisotropic around its maximum value and the nematic director is density dependent even at very high densities, i.e., the structure of one-dimensional fluid is always tilted. It is found that the density dependence of the tilted structure depends strongly on the shape of the zigzags. Surprisingly, the Onsager theory produces quite accurate results for the order parameters and tilt angles even in very dense systems.

Gurin, Péter; Varga, Szabolcs

2010-10-01

274

The Teaching of Values.  

ERIC Educational Resources Information Center

Reviews prior approaches to instilling values so as to discuss the importance of teaching values now. Suggests how student affairs preparation program curricula can help practitioners learn how to teach values. Identifies five recent changes in campus values and uses examples to show how student affairs practitioners use core values. (RJM)

Moore, Leila V.; Hamilton, Deborah H.

1993-01-01

275

Glass transition of hard spheres in high dimensions.  

PubMed

We have investigated analytically and numerically the liquid-glass transition of hard spheres for dimensions d-->infinity 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 approximately d1/2, but become identical on a scale k approximately d, which is proven analytically. The critical packing fraction phic(d) approximately d(2)2(-d) is above the corresponding Kauzmann packing fraction phiK(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. PMID:20481726

Schmid, Bernhard; Schilling, Rolf

2010-04-01

276

Market value, fair value, and duress  

Microsoft Academic Search

Purpose – This paper seeks to consider a significant market misconception and related errors commonly made by valuers, financial decision makers, and other users of valuation services. Its purpose is to focus on the importance of relating the explicit requirements of market value and fair value definitions to the evidence required for a supportable opinion of either. Design\\/methodology\\/approach – The

John Dorchester Jr

2011-01-01

277

Secondary hardness of alloy white irons  

SciTech Connect

This paper describes an investigation of the phase composition, structure, and hardness of hardened and tempered white irons alloyed with chromium and molybdenum. The selection of the optimum (from the point of view of secondary hardness) hardening temperature was made on 15 X 15 mm disk specimens of 4Kh16 iron. The results of this investigation of a large number of heats of white iron containing 2.53.5% C, from 0 to 30% Cr, and 0.5% Mo showed that the maximum secondary hardness may be obtained in tempering of irons containing 5-10% Cr hardened from 1100/sup 0/C. With an increase in molybdenum content in the experimental chromium irons the area of appearance of the maximum hardness shifts to higher temperatures and the interval of these temperatures is broadened. It is found that the secondary hardness of chromium white irons is determined by the quantity of residual austenite in the hardened condition and its decomposition in tempering.

Potapova, M.S.; Morozova, I.G.; Sokol, I.Ya.

1986-01-01

278

Haptic Search for Hard and Soft Spheres  

PubMed Central

In this study the saliency of hardness and softness were investigated in an active haptic search task. Two experiments were performed to explore these properties in different contexts. In Experiment 1, blindfolded participants had to grasp a bundle of spheres and determine the presence of a hard target among soft distractors or vice versa. If the difference in compliance between target and distractors was small, reaction times increased with the number of items for both features; a serial strategy was found to be used. When the difference in compliance was large, the reaction times were independent of the number of items, indicating a parallel strategy. In Experiment 2, blindfolded participants pressed their hand on a display filled with hard and soft items. In the search for a soft target, increasing reaction times with the number of items were found, but the location of target and distractors appeared to have a large influence on the search difficulty. In the search for a hard target, reaction times did not depend on the number of items. In sum, this showed that both hardness and softness are salient features. PMID:23056197

van Polanen, Vonne; Bergmann Tiest, Wouter M.; Kappers, Astrid M. L.

2012-01-01

279

Barcoll hardness of different resin-based composites cured by halogen or light emitting diode (LED).  

PubMed

The clinical performance of light curing resin composites is greatly influenced by the quality of the light-curing unit (LCU). Halogen LCUs are commonly used for curing composite materials. However, they have some drawbacks. The development of new, blue, super bright light emitting diodes (LED LCU) of 470-nm wavelength with high light irradiance comes as an alternative to standard halogen LCUs of 450-470-nm wavelengths. This study evaluated the surface hardness of the different resin-based composites (flowable, hybrid and packable resin composites) cured by LED LCU or halogen LCU. A Teflon mold 10-mm in diameter and 2-mm in depth was made to obtain five disk-shaped specimens for each experimental group. Then, the specimens were cured by an LED LCU or halogen LCU for 40 seconds. The hardness of the upper and lower surfaces was measured with a Barcoll hardness-measuring instrument. The statistical analysis was performed using one-way analysis of variance (ANOVA) and Duncan test at a p=0.05 significance level. The results of the hardness test indicated that the hardness of resin composites cured by an LED LCU were greater than those cured by a halogen LCU. Additionally, for all resin-based composites, the hardness values for the upper surfaces were higher than the lower surfaces. However, for both results no statistically significant differences were observed (p>0.05). PMID:15765960

Bala, Oya; Uçtasli, Mine Betül; Tüz, M Atilla

2005-01-01

280

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

281

Using Nondeterminism to Amplify Hardness # Alexander Healy + Salil Vadhan #  

E-print Network

Using Nondeterminism to Amplify Hardness # Alexander Healy + Salil Vadhan # Division of Engineering revisit the problem of hardness amplification in NP , as recently studied by O'Donnell (STOC `02). We amplify to hardness 1/2 - 1/n #(1) . 2. If s(n) = 2 n# , we amplify to hardness 1/2 - 1/2 n# . 3. If s

Vadhan, Salil

282

Hard X-ray properties of magnetic cataclysmic S. Scaringi  

E-print Network

Hard X-ray properties of magnetic cataclysmic variables S. Scaringi , A.J. Bird , A.J. Norton , C arising from this hard X-ray selected sample and find that most hard X-ray detected mCVs have Pspin in the context of mCV evolution scenarios. We also present evidence for corre- lations between hard X

Norton, Andrew J.

283

The Hardness of 3-Uniform Hypergraph Coloring Irit Dinur  

E-print Network

The Hardness of 3-Uniform Hypergraph Coloring Irit Dinur Oded Regev Clifford Smyth December 6, 2004 Abstract We prove that coloring a 3-uniform 2-colorable hypergraph with c colors is NP-hard with c2 colors is NP-hard; the case k = 2, however, remains wide open. This is the first hardness result

Smyth, Clifford

284

Using Nondeterminism to Amplify Hardness # Alexander Healy + Salil Vadhan #  

E-print Network

Using Nondeterminism to Amplify Hardness # Alexander Healy + Salil Vadhan # Division of Engineering revisit the problem of hardness amplification in NP , as recently studied by O'Donnell (JCSS `04). We amplify to hardness 1/2 - 1/n #(1) . 2. If s(n) = 2 n# , we amplify to hardness 1/2 - 1/2 n# . 3. If s

Vadhan, Salil

285

Using Nondeterminism to Amplify Hardness Alexander Healy # Salil Vadhan +  

E-print Network

Using Nondeterminism to Amplify Hardness Alexander Healy # Salil Vadhan + Harvard University Emanuele Viola # ABSTRACT We revisit the problem of hardness amplification in NP, as recently studied by O(n) = n #(1) , we amplify to hardness 1/2 - 1/n #(1) . 2. If s(n) = 2 n #(1) , we amplify to hardness 1

Viola, Emanuele

286

On the Hardness of Approximating the Chromatic Number Sanjeev Khanna  

E-print Network

On the Hardness of Approximating the Chromatic Number Sanjeev Khanna Stanford University Nathan considers the computational hardness of ap­ proximating the chromatic number of a graph. We first give itself) is NP­hard. We then consider the hardness of coloring a 3­colorable graph with as few as possible

Pennsylvania, University of

287

Flavor Characterization of Breads Made from Hard Red Winter Wheat and Hard White Winter Wheat  

Microsoft Academic Search

Cereal Chem. 69(5):556-559 Sensory flavor profiles for white pan bread and whole wheat bread impression than did HRW crust. HRW crumb was sweeter and more made from hard red winter (HRW) or hard white winter (HWW) wheat dairylike than HWW crumb. HWW crumb had a phenoliclike note not were developed by a professionally trained panel. The flavors of crust present

CHUN-YEN CHANG; EDGAR CHAMBERS

288

Development of hard white winter wheats for a hard red winter wheat region  

Microsoft Academic Search

Hard white winter wheat (HWWW) occupies a very limited area of the USA, but its purported advantages suggest that its production in the major hard red winter wheat (HRWW) region may be feasible. Objectives of our investigations were to develop experimental HWWW lines that combined desirable attributes-grain yield, functional grain quality, and resistance to preharvest sprouting-in single genotypes for comparison

M. P. Upadhyay; G. M. Paulsen; E. G. Heyne; R. G. Sears; R. C. Hoseney

1984-01-01

289

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

ERIC Educational Resources Information Center

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

Phillips, D. C.

2014-01-01

290

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

ERIC Educational Resources Information Center

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

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

2005-01-01

291

COMPARISON OF QUALITY CHARACTERISTICS AND BREADMAKING FUNCTIONALITY OF HARD RED WINTER AND HARD RED SPRING WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Various whole-kernel, milling, flour, dough, and breadmaking quality parameters were compared between hard red winter (HRW) and hard red spring (HRS) wheat. From the 43 quality parameters evaluated, only eight quality characteristics - test weight, moisture content, kernel size, polyphenol oxidase ...

292

Improvement of RRO using hybrid-type STW for hard disk drives  

Microsoft Academic Search

Accurate servo track writers (STWs) are indispensable for hard disk drives (HDDs) with high track density. We have developed a prototype hybrid-type STW, which has two writing stages, and compared the servo patterns with those by the conventional STW. The experimental results are described showing that the hybrid-type STW reduces the maximum value of repeatable runout (RRO) by about 40%

Takahiro Inoue; Makoto Horisaki; Yousuke Seo; Shizuo Yamazaki

2000-01-01

293

A STUDY OF SOLVENT RETENTION CAPACITY (SRC) TESTS IN HARD WINTER WHEAT FLOUR  

Technology Transfer Automated Retrieval System (TEKTRAN)

The suitability of SRC was investigated in assessing hard winter wheat (HWW) product quality. Four SRC values with 5% lactic acid (LA), 50% sucrose (SU), 5% sodium carbonate (SC) and water of 116 HWW samples were measured. Quality parameters were tested using methods such as SKCS, NIR spectroscopy...

294

Hardness Results for Cake Cutting Costas Busch Mukkai S. Krishnamoorthy Malik Magdon-Ismail  

E-print Network

Hardness Results for Cake Cutting #3; Costas Busch Mukkai S. Krishnamoorthy Malik Magdon,moorthy,magdong@cs.rpi.edu March 11, 2003 Abstract Fair cake-cutting is the division of a cake or resource among N users so that each user is content. Users may value a given piece of cake di#11;erently, and information about how

Magdon-Ismail, Malik

295

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

2015-01-01

296

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

297

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

298

Effects of different solutions on the surface hardness of composite resin materials.  

PubMed

In this study, the surface hardness of five light-cured composite resins were evaluated, namely: filled (Estelite), nanofil (AElite), unfilled (Valux Plus), hybrid (Tetric ceram), and Ormocer-based (Admira) composite resins. The microhardness values of composite specimens were measured at the top and bottom surfaces after 24 hours or 30 days of immersion in different solutions (tea, coffee, Turkish coffee, mouthwash, cola, and distilled water). Comparisons were made with univariate analysis of variance and Duncan's multiple range test. It was found that rough specimens of reinforced nano-hybrid composite material immersed in cola for 30 days had the lowest surface hardness (33.20), whereas rough specimens of hybrid composite material immersed in cola for 24 hours had the highest surface hardness (156.00). In both tea and coffee, the top surfaces tended to be harder than the bottom ones. In conclusion, the five different materials exhibited different hardnesses, and that the hardness values of composite materials were statistically different in different immersion solutions. PMID:19662734

Yaniko?lu, Nuran; Duymu?, Zeynep Ye?il; Yilmaz, Baykal

2009-05-01

299

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

300

Hard template synthesis of metal nanowires  

PubMed Central

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

301

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

302

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 Hardingâ??s 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

303

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

304

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 Shirley Baker Hard ClamHard Clam Shirley Baker University if Florida SFRC Fisheries and Aquatic SciencesBivalvia ­­ clams, oysters, scallops, musselsclams, oysters, scallops, mussels #12;Cl Bi l iClass Bivalvia ­ 20

Florida, University of

305

Binding of hard and soft metal ions to Rhizopus arrhizus biomass  

Microsoft Academic Search

The greater the covalent index value of a metal ion, the greater its potential to form covalent bonds with biological ligands. In this study, freeze-dried Rhizopus arrhizus biomass was tested for its potential to adsorb the hard metal ion Sr2+ and the borderline metal ions Mn2+, Zn2+, Cd2+, Cu2+, and Pb2+ from aqueous solutions. Equilibrium metal uptake values increased in

Joseph M. Brady; John M. Tobin

1995-01-01

306

Radiation-hard static induction transistor  

SciTech Connect

The static induction transistor (SIT) has been proposed as a preferred power switching device for applications in military and space environments because of its potential for radiation hardness, high-frequency operation, and the incorporation of on-chip smart power sensor and logic functions. Design, fabrication, and characteristics of a 350 V, 100 A buried gate SIT are described. The potential radiation hardness of this class of devices was evaluated by measurement of SIT characteristics after irradiation with 100 Mrad electrons (2 MeV), and up to 10%16% fission neutrons/cm/sup 2/. High-temperature operation and the possibility of radiation damage self-annealing are discussed.

Hanes, M.H.; Bartko, J.; Hwang, J.M.; Rai-Choudhury, P.; Leslie, S.G.

1988-12-01

307

Universality of the hard-loop action  

NASA Astrophysics Data System (ADS)

The effective actions of gauge bosons, fermions, and scalars, which are obtained within the hard-loop approximation, are shown to have unique forms for a whole class of gauge theories including QED, scalar QED, super QED, pure Yang-Mills, QCD, and super Yang-Mills. The universality occurs irrespective of a field content of each theory and of a variety of specific interactions. Consequently, the long-wavelength or semiclassical features of plasma systems governed by these theories such as collective excitations are almost identical. An origin of the universality, which holds within the limits of applicability of the hard-loop approach, is discussed.

Czajka, Alina; Mrówczy?ski, Stanis?aw

2015-01-01

308

Hard Diffraction -- from Blois 1985 to 2005  

E-print Network

The idea of diffractive processes with a hard scale involved, to resolve the underlying parton dynamics, was presented at the first Blois conference in 1985 and experimentally verified a few years later. Today hard diffraction is an active research field with high-quality data and new theoretical models. The trend from Regge-based pomeron models to QCD-based parton level models has given insights on QCD dynamics involving perturbative gluon exchange mechanisms, including the predicted BFKL-dynamics, as well as novel ideas on non-perturbative colour fields and their interactions.

Gunnar Ingelman

2005-11-15

309

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

310

Application of the hard and soft acids and bases concept to explain ligand coordination in double salt structures  

NASA Astrophysics Data System (ADS)

The coordination polyhedra in 43 double salt structures are examined. Each structure is formed by at least two kinds of polyhedra. The differences in the environment around the metal ions are explained using HSAB concept. The values of hardness for 25 cations are calculated according to Klopman. A factor ? = Hacid· Hbase, where H is the hardness value, is introduced. The value of this factor can be used as a criterion for the stability of the complexes. The possibilities which the ? factor gives in explaining ligand coordination in known structures as well as for predicting structures for double salts are illustrated.

Balarew, Christo; Duhlev, Rumen

1984-11-01

311

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

312

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

313

Fair Value Measurements  

Microsoft Academic Search

In recent years, FASB has been taking the lead in fair value measurements research. In September 2006, FASB issued SFAS No. 157, fair value measurements, which are the first and the most comprehensive accounting standard about fair value. The standard lays a substantial basis for the application of fair value, gives us beneficial enlightenment and urges us to take actual

Caifeng Zhang

2008-01-01

314

Values and Creativity.  

ERIC Educational Resources Information Center

The paper discusses creativity and the creative process, cites current methods used to improve creativity in the workplace, and explains the concept of values and value systems as they relate to creativity. Values and value systems are defined; and their source, their nature and functions, and their measurement are outlined. (JDD)

Fernald, Lloyd W., Jr.

1987-01-01

315

Values: A Symposium Report.  

ERIC Educational Resources Information Center

This publication brings together a set of four papers prepared for a symposium on values at the 1972 annual meeting of the American Educational Research Association. The first paper, by Fred N. Kerlinger, establishes a rationale for values research. The discussion focuses on the definition of values, relationship between values and attitudes,…

Ryan, T. A., Ed.

316

Soft-to-Hard transition in MAXI J1659-152  

NASA Astrophysics Data System (ADS)

Recent RXTE observations of MAXI J1659-152 (Negoro et al. 2010, ATel #2873; Mangano et al. 2010, GCN #11296) show that MAXI J1659-152 performed a transition from soft states to the hard intermediate state between Oct 31 (07:51 UT; observation 95118-01-16-00) and Nov 01 (05:15; observation 95118-01-16-01). A timing analysis of these two observations shows that fractional rms increases from 8% to 15% during the above period, being now consistent with the typical values observed in the hard intermediate state (Muñoz-Darias et al., 2010, arXiv:1008.0558).

Muñoz-Darias, T.; Stiele, H.; Belloni, T. M.; Motta, S.

2010-11-01

317

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

318

Tolerating Hard Faults in Microprocessor Array Structures  

Microsoft Academic Search

In this paper, we present a hardware technique, called Self-Repairing Array Structures (SRAS), for masking hard faults in microprocessor array structures, such as the reorder buffer and branch history table. SRAS masks errors that could otherwise lead to slow system recover- ies. To detect row errors, every write to a row is mir- rored to a dedicated \\

Fred A. Bower; Paul G. Shealy; Sule Ozev; Daniel J. Sorin

2004-01-01

319

21 CFR 133.150 - Hard cheeses.  

Code of Federal Regulations, 2010 CFR

...not less than 143 °F for a period of not less than 30 minutes, or for a time and at a temperature equivalent thereto in phosphatase destruction. A hard cheese shall be deemed not to have been made from pasteurized milk if 0.25 gram shows a phenol...

2010-04-01

320

Classic and Hard-Boiled Detective Fiction.  

ERIC Educational Resources Information Center

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

Reilly, John M.

321

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

322

HARD BREMSSTRAHLUNG PHOTONS FROM GRAVITON EXCHANGE  

E-print Network

HARD BREMSSTRAHLUNG PHOTONS FROM GRAVITON EXCHANGE #3; LC-TH-2004-015 T. BUANES, E.W. DVERGSNES Abstract We review photon Bremsstrahlung in extra-dimensional models with massive gravitons. The photon spectrum is harder than in the Standard Model. In the RS scenario, radiative return to gravitons below

323

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

324

IB Scholars! You've worked hard.  

E-print Network

Attention IB Scholars! You've worked hard. Now Oregon State University wants to reward your efforts. OSU offers you exclusive benefits when you complete your full IB diploma: · Sophomore academic standing · At least $3,000 in scholarships See the reverse side for specific IB course information For more

Escher, Christine

325

Ototraumatic Effects of Hard Rock Music  

PubMed Central

Temporary and permanent shifts in auditory thresholds were found in 43 hard rock musicians and temporary shifts were also observed in some listeners. The threshold shifts involved all of the conventional puretone test frequencies. Custom-fitted polyvinyl chloride ear protectors were found to be effective in prevention of these noise-induced hearing losses. PMID:5008499

Reddell, Rayford C.; Lebo, Charles P.

1972-01-01

326

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.

327

Hard Tissue Pediatric Facial Trauma: A Review  

Microsoft Academic Search

J Can Dent Assoc 2006; 72(6):555-8 This article has been peer reviewed. Although hard tissue injuries are uncommon in the pediatric patient, dentists may be involved in the initial assessment of these patients. In this paper, we review fractures of the facial skeleton with a focus on dentoalveolar injuries. Minimally displaced fractures in pediatric patients can be managed conservatively, while

Nicholas J. V. Hogg; Bruce B. Horswell

328

Hardness and softness in density functional theory  

Microsoft Academic Search

The fundamental equations to describe the change from one ground-state to another, in the framework of density functional theory, are used to analyze a set of hardness and softness functions that are hierarchized as non-local, local and global quantities. Through these definitions it is shown that under conditions of constant chemical potential, the interaction between two chemical systems evolves towards

José Gázquez

329

Imaging in Hard X-ray Astronomy  

E-print Network

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

T. P. Li

2002-12-02

330

Classic Nintendo Games are (Computationally) Hard  

E-print Network

game franchises: Mario, Donkey Kong, Legend of Zelda, Metroid, and Pok´emon. Our results apply­3; all Legend of Zelda games; all Metroid games; and all Pok´emon role-playing games. In addition, we, Legend of Zelda, Metroid, and Pok´emon. We prove that it is NP-hard, and in some cases PSPACE

Demaine, Erik

331

Hard thermal loops in static external fields  

E-print Network

We study, in the imaginary-time formalism, the high temperature behavior of n-point thermal loops in static Yang-Mills and gravitational fields. We show that in this regime, any hard thermal loop gives the same leading contribution as the one obtained by evaluating the loop at zero external energies and momenta.

J. Frenkel; S. H. Pereira; N. Takahashi

2009-02-04

332

Radiation-Hardness Data For Semiconductor Devices  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

333

Hard and Easy Distributions of SAT Problems  

Microsoft Academic Search

We report results from large-scale experiments in satisfiabilitytesting. As has been observed by others, testingthe satisfiability of random formulas often appears surprisinglyeasy. Here we show that by using the rightdistribution of instances, and appropriate parametervalues, it is possible to generate random formulas thatare hard, that is, for which satisfiability testing is quitedifficult. Our results provide a benchmark for the evaluationof

David G. Mitchell; Bart Selman; Hector J. Levesque

1992-01-01

334

Where the Really Hard Problems Are  

Microsoft Academic Search

It is well known that for many NP-complete problems, such as K-Sat, etc., typical cases are easy to solve; so that computationally hard cases must be rare (assuming P = NP). This paper shows that NP-complete problems can be summarized by at least one \\

Peter Cheeseman; Bob Kanefsky; William M. Taylor

1991-01-01

335

Approximation Algorithms for NP-Hard Problems  

Microsoft Academic Search

Approximation algorithms have developed in response to the impossibility of solving a great variety of important optimization problems. Too frequently, when attempting to get a solution for a problem, one is confronted with the fact that the problem is NP-hard. This, in the words of Garey and Johnson, means \\

1997-01-01

336

On the hardness of approximating minimization problems  

Microsoft Academic Search

We prove results indicating that it is hard to compute efficiently good approximate solutions to the Graph Coloring, Set Covering and other related minimization problems. Specifi- cally, there is an E > 0 such that Graph Coloring cannot be approximated with ratio n' unless P = NP. Set Covering cannot be approximated with ratio c log n for any c

Carsten Lund; Mihalis Yannakakis

1993-01-01

337

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

338

Pair distribution function for fluid hard spheres  

Microsoft Academic Search

The pair distribution function of a system of fluid hard spheres is calculated by means of a simple generalization of the Percus-Yevick theory. A relation between the pair distribution function and the direct correlation function which leads to self-consistent results from the pressure and compressibility equations of state and which is similar, but not identical, to a proposal of Rowlinson,

R. O. Watts; D. Henderson

1969-01-01

339

How do hard, regular tetrahedra pack?  

Microsoft Academic Search

We simulate a system of hard tetrahedra using Monte Carlo simulations and determine the density-pressure equation of state by compressing an initially disordered fluid. Depending on the speed of the compression, the system either jams or spontaneously orders to a quasicrystal. By compressing a crystalline approximant of the quasicrystal, the highest packing fraction we obtain is 0.8503. We show that

Michael Engel; Amir Haji-Akbari; Aaron S. Keys; Xiaoyu Zheng; Rolfe G. Petschek; Peter Palffy-Muhoray; Sharon C. Glotzer

2010-01-01

340

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...

341

Hard Times: Philosophy and the Fundamentalist Imagination  

ERIC Educational Resources Information Center

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

Allsup, Randall Everett

2005-01-01

342

Help! Libraries and the Hard of Hearing.  

ERIC Educational Resources Information Center

This transcript contains the text of three speeches on the problems of people with hearing impairments and the provision of library services to the hard of hearing. Howard Edward (Rocky) Stone, founder of Self-Help-For-Hearing-Impaired-People, Inc., describes his difficulties as a hearing impaired person, the growing number of Americans with…

1982

343

Factorization and scaling in hard diffraction  

SciTech Connect

We compare results on diffractive W-boson production at the Tevatron with predictions based on the diffractive structure function measured in deep inelastic scattering at HERA assuming (a) conventional factorization or (b) hard factorization combined with a rapidity gap distribution scaled to the total gap probability. We find that conventional factorization fails, while the scaling prediction agrees with the data.

Goulianos, Konstantin [Rockefeller University, New York, New York 10021 (United States)

1997-04-20

344

7 CFR 201.57 - Hard seeds.  

Code of Federal Regulations, 2010 CFR

...an impermeable seed coat, are to be counted as “hard seed.” If at the end of the germination period provided for legumes, okra, cotton and dichondra in these rules and regulations there are still present swollen seeds or seeds of these kinds...

2010-01-01

345

Calculating the real value of e-learning  

Microsoft Academic Search

Many companies view their training budget strictly as a cost centre which is susceptible to cuts when the business needs to reign in expenses. In this article, the author explores the benefits of training investments with a particular focus upon measuring the value of delivering training via an enterprise e-learning initiative. In addition to the many hard\\/measurable returns, the piece

Eugene Deeny

2003-01-01

346

Effect of polishing burs and stones on the micro-hardness of dental amalgam.  

PubMed

Square standard cavities were prepared in human teeth and restored with amalgam obtained from alloys of different trade-marks. Twenty-four hours after condensation, excess amalgam was removed from three of the four margins, each with a different rotatory instrument (number 4 bur, multiblade finishing bur, and fine green stone). No rotatory instrument was used on the fourth margin (control), and this control was polished with pumice and zinc-oxide pastes and Sweeney's brushes. Vickers' tests for micro-hardness of the amalgam were performed on the four margins of the restorations. The restorations were then submitted to metallographic polishing, and a second micro-hardness measurement was made seven days later. The statistical analysis of the data showed that micro-hardness values were higher at the margins on which no rotatory instruments were used. The lowest micro-hardness values were found at the margins where finishing and/or round burs were used. Polishing with fine green stones gave intermediate values. PMID:1290913

Ribeiro, S A; do Nascimento, T N; Centola, A L; Teixeira, L C; Campos, S M

1992-01-01

347

Influence of polymerization time and depth of cure of resin composites determined by Vickers hardness  

PubMed Central

Background: Adequate polymerization of resin composites could be considered as a crucial factor in obtaining good clinical performance, particularly in stress-bearing areas. An insufficient curing degree affects the resin composite's chemical properties The current in vitro study evaluated the influence of polymerization time and depth of cure of six commercial resin composites by Vickers microhardness (VK). Materials and Methods: Six resin composites were selected: Three microhybrid (Esthet.X HD, Amaris, Filtek Silorane), two nanohybrid (Grandio, Ceram.X mono), and one nanofilled (Filtek Supreme XT). The VK of the surface was determined by a microhardness tester using a Vickers diamond indenter and a 200 g load applied for 15 s. The bottom to top mean VK ratio was calculated using the formula: Hardness ratio = VK of bottom surface/VK of top surface. Vickers hardness values of test materials during exposure time of 20 and 40 s and depths of cure of 2 and 3 mm were determined and compared. Data were analyzed using analysis of variance (ANOVA) test. Results: For all the tested materials and with all the exposure time periods, hardness ratio was higher than the minimum value indicated in literature (0.8). Exposure time and depth of cure did not affect hardness ratio values for Filtek Silorane, Grandio, and Filtek Supreme XT. Conclusion: Among the materials tested, the nanofilled and the nanohybrid resin composites were rather insensible to thickness variations. Miicrohybrid composites, instead, had features different from one another. PMID:23559951

Lombardini, Marco; Chiesa, Marco; Scribante, Andrea; Colombo, Marco; Poggio, Claudio

2012-01-01

348

Process for casting hard-faced, lightweight camshafts and other cylindrical products  

DOEpatents

A process for casting a hard-faced cylindrical product such as an automobile camshaft includes the steps of: (a) preparing a composition formed from a molten base metal and an additive in particle form and having a hardness value greater than the hardness value of the base metal; (b) introducing the composition into a flask containing a meltable pattern of a cylindrical product such as an automobile camshaft to be manufactured and encased in sand to allow the composition to melt the pattern and assume the shape of the pattern within the sand; and (c) rotating the flask containing the pattern about the longitudinal axes of both the flask and the pattern as the molten base metal containing the additive in particle form is introduced into the flask to cause particles of the additive entrained in the molten base metal to migrate by centrifugal action to the radial extremities of the pattern and thereby provide a cylindrical product having a hardness value greater at it's radial extremities than at its center when the molten base metal solidifies.

Hansen, Jeffrey S. (Corvallis, OR); Turner, Paul C. (Albany, OR); Argetsinger, Edward R. (Albany, OR); Wilson, Rick D. (Corvallis, OR)

1996-01-01

349

Stopping the Brain Drain of Skilled Veteran Teachers: Retaining and Valuing Their Hard-Won Experience  

ERIC Educational Resources Information Center

Veteran educators are being encouraged to take early retirement in order to create jobs for less-experienced, lower-paid novices. Veteran educators are not alone: early retirement promotions have become the norm for aging workers in America. Consequently, there is a brain-drain of skilled workers at the national, state, and local levels. The early…

Fibkins, William L.

2011-01-01

350

A collocation method for certain elliptic boundary-value problems  

E-print Network

A COLLOCATION METHOD FOR CERTAIN ELLIPTIC BOUNDARY-VALUE PROBLEMS A Thesis Susan Kathleen Hard Submitted to the Graduate Co ilepe of Texas ABM University in partial fulfillment of the requirement for. the ilegreu of, MASTER OF SCIENCE May... 1974 Major Subject: Mathematics A COLLOCATION METHOD FOR CERTAIN ELLIPTIC BOUNDARY-VALUE PROBLEMS A Thesis by Susan Kathleen Hord Approved as to style and content by: (Chairman o Committee) (Head of Department) (Member) (Member) May 1974...

Hord, Susan Kathleen

1974-01-01

351

Impact Assessment of Agricultural Value Chain Development why it is difficult, rarely undertaken and  

E-print Network

Impact Assessment of Agricultural Value Chain Development ­ why it is difficult, rarely undertaken of agricultural value chains is assumed to support pro-poor rural develop- ment, especially where smallholder, a comprehensive analysis of poverty impacts of agricultural value chain development is hard to find. The author

Krivobokova, Tatyana

352

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

PubMed

Ayers, Parr, and Pearson recently showed that insight into the hard/soft acid/base (HSAB) principle could be obtained by analyzing the energy of reactions in hard/soft exchange reactions, i.e., reactions in which a soft acid replaces a hard acid or a soft base replaces a hard base [J. Chem. Phys., 2006, 124, 194107]. We show, in accord with the maximum hardness principle, that the hardness increases for favorable hard/soft exchange reactions and decreases when the HSAB principle indicates that hard/soft exchange reactions are unfavorable. This extends the previous work of the authors, which treated only the "double hard/soft exchange" reaction [P. K. Chattaraj and P. W. Ayers, J. Chem. Phys., 2005, 123, 086101]. We also discuss two different approaches to computing the hardness of molecules from the hardness of the composing fragments, and explain how the results differ. In the present context, it seems that the arithmetic mean of fragment softnesses is the preferable definition. PMID:17637976

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

2007-08-01

353

Thermodynamic perturbation theory for fused hard-sphere and hard-disk chain fluids  

SciTech Connect

We find that first-order thermodynamic perturbation theory (TPT1) which incorporates the reference monomer fluid used in the generalized Flory--{ital AB} (GF--{ital AB}) theory yields an equation of state for fused hard-sphere (FHS) chain fluids that has accuracy comparable to the GF--{ital AB} and GF--dimer--{ital AC} theories. The new TPT1 equation of state is significantly more accurate than other extensions of the TPT1 theory to FHS chain fluids. The TPT1 is also extended to two-dimensional fused hard-disk chain fluids. For the fused hard-disk dimer fluid, the extended TPT1 equation of state is found to be more accurate than the Boublik hard-disk dimer equation of state. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Zhou, Y.; Hall, C.K. [Department of Chemical Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905 (United States)] [Department of Chemical Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905 (United States); Stell, G. [Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400 (United States)] [Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400 (United States)

1995-08-15

354

Thermodynamic perturbation theory for fused hard-sphere and hard-disk chain fluids  

NASA Astrophysics Data System (ADS)

We find that first-order thermodynamic perturbation theory (TPT1) which incorporates the reference monomer fluid used in the generalized Flory-AB (GF-AB) theory yields an equation of state for fused hard-sphere (FHS) chain fluids that has accuracy comparable to the GF-AB and GF-dimer-AC theories. The new TPT1 equation of state is significantly more accurate than other extensions of the TPT1 theory to FHS chain fluids. The TPT1 is also extended to two-dimensional fused hard-disk chain fluids. For the fused hard-disk dimer fluid, the extended TPT1 equation of state is found to be more accurate than the Boublík hard-disk dimer equation of state.

Zhou, Yaoqi; Hall, Carol K.; Stell, George

1995-08-01

355

Redox and Lewis acid-base activities through an electronegativity-hardness landscape diagram.  

PubMed

Chemistry is the science of bond making and bond breaking which requires redistribution of electron density among the reactant partners. Accordingly acid-base and redox reactions form cardinal components in all branches of chemistry, e.g., inorganic, organic, physical or biochemistry. That is the reason it forms an integral part of the undergraduate curriculum all throughout the globe. In an electronegativity (?)- hardness (?) landscape diagram the diagonal ??=?? line separates reducing agents from oxidizing agents as well as Lewis acids from Lewis bases. While electronegativity is related to the degree of electron transfer between two reactants, hardness is related to the resistance to that process. Accordingly the electronegativities of oxidizing agents/Lewis acids are generally greater than the corresponding hardness values and the reverse is true for reducing agents/Lewis bases. Electrophiles and nucleophiles are also expected to follow similar trends. PMID:24043544

Das, Ranjita; Vigneresse, Jean-Louis; Chattaraj, Pratim Kumar

2013-11-01

356

Implementing value strategy through the value chain  

Microsoft Academic Search

This article is a corollary to three articles published earlier in Management Decision. More precise definitions of a modern value chain are proposed, in terms of it being a business system that creates end-user satisfaction and realises the objectives of other member stakeholders. Comparisons are drawn with the current notion of supply chain management and an explanation is given as

David Walters; Geoff Lancaster

2000-01-01

357

ValuePro Stock Value Calculator  

NSDL National Science Digital Library

This online calculator tabulates the baseline valuation for any publicly traded stock. Enter the stock's ticker symbol, and the program will value the stock. Users may also change any of the input for a stock and revalue it. The site contains a brief helpful guide to using online valuation and a thoughtful review of the product from Business Week.

358

The value of values Birmingham's got talent  

E-print Network

to learn about the University's research into character and values (page 40). I have also learnt about the wonderful new Bramall Music Building in all its splendour. This completes the Aston Webb semicircle-new sports centre which will be a fitting home for the University's participatory and elite sport. When

Birmingham, University of

359

Valuing the Self  

Microsoft Academic Search

\\u000a This author notes that, increasingly, educators agree that schools should teach values rather than merely teach about or clarify\\u000a values. Thus, trends such as character education and social and emotional learning have replaced Kohlberg’s cognitive-developmental\\u000a approach, and ‘the self’ has emerged as an independent source and focus of value. Nevertheless, values education continues\\u000a to be a divisive field. After a

Kristján Kristjánsson

360

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.

361

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

362

Preparation of sharp-melting hard palm midfraction and its use as hard butter in chocolate  

Microsoft Academic Search

Preparation of hard palm midfractions (PMF) and its use as a cocoa butter equivalent ingredient were studied. Hard PMF is\\u000a obtained by multistep fractionation of palm oil involving dry fractionation (DF) and\\/or solvent fractionation (SF), usually\\u000a using hexane or acetone. From our experience, in acetone, a polar solvent, symmetrical 1,3-disaturated triacylglycerols tend\\u000a to selectively crystallize more than nonsymmetrical 1,2- or

Satsuki Hashimoto; Toru Nezu; Hiroshi Arakawa; Tomonori Ito; Shoji Maruzeni

2001-01-01

363

Fixing fair value accounting  

Microsoft Academic Search

The concept of fair value accounting was introduced in 1993 to make financial statements easier to compare and balance sheets more reflective of real values. This article discusses the true consequences of fair value accounting and its impact on the stability of financial institutions. By Peter J. Wallison, American Enterprise Institute

Peter J. Wallison

2009-01-01

364

The value of superstitions  

Microsoft Academic Search

This paper estimates the value of superstitions by studying the auctions of vehicle license plates. We show that the value of superstitions is economically significant, which justifies their persistence in human civilization. We also document the changes of the value of superstitions across different types of plates, across different policy regimes, and across different macroeconomic environments. Interestingly, some of the

Travis Ng; Terence Chongy; Xin Du

2010-01-01

365

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...

366

Education and Values.  

ERIC Educational Resources Information Center

The role of the university in moral and value issues are discussed in a 1987 inaugural address by the president of Indiana University. He suggests that a college education should include values through both intellectual inquiry and example. Liberty to speak and write is an essential value if faculty and students are to achieve their academic…

Ehrlich, Thomas

367

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 ...

Mrs. Korth

2009-07-27

368

Human Values in Management  

Microsoft Academic Search

The essay begins by the author's recollections of his younger days when people were seldom worried about moral decline in society. Today, however, it has become a real concern. Literature, philosophy, spiritual works are all essentially a celebration of human values. The paper examines the issue of scale of graded values as against that of absolutist universal values. A scrutiny

R. K. Dasgupta

1997-01-01

369

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

370

Value and Vision.  

ERIC Educational Resources Information Center

Discusses the value of public libraries and what it means to be valuable. Topics include shrinking library budgets; why there is public money for libraries; how to tell whether a service, product, or institution creates public value; political and legal support; administrative and operational feasibility; and enhancing public value. (LRW)

Rodger, Eleanor Jo

2002-01-01

371

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.

372

Nearest Neighbor Value Interpolation  

Microsoft Academic Search

This paper presents the nearest neighbor value (NNV) algorithm for high resolution (H.R.) image interpolation. The difference between the proposed algorithm and conventional nearest neighbor algorithm is that the concept applied, to estimate the missing pixel value, is guided by the nearest value rather than the distance. In other words, the proposed concept selects one pixel, among four directly surrounding

Rukundo Olivier; Cao Hanqiang; HUST Wuhan

2012-01-01

373

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

374

Phase transition, equation of state, and limiting shear viscosities of hard sphere dispersions  

NASA Astrophysics Data System (ADS)

Despite an interparticle potential consisting of only an infinite repulsion at contact, the thermodynamics and dynamics of concentrated dispersions of hard spheres are not yet fully understood. Colloidal poly-(methyl methacrylate) spheres with a grafted layer of poly-(12-hydroxy stearic acid) (PMMA-PHSA) comprise a common model for investigating structural, dynamic, and rheological properties. These highly monodisperse spheres can be index matched in nonaqueous solvents, reducing van der Waals forces and allowing characterization via light scattering. In this work, we test the behavior of these dispersions against expectations for hard spheres through observations of the phase behavior, x-ray densitometry of equilibrium sediments, and Zimm viscometry. We set the effective hard sphere volume fraction by the disorder-order transition, thereby accounting for the polymer layer, any swelling due to the solvent, and polydispersity. The melting transition then occurs close to the expected value and the equation of state for the fluid phase, extracted from the equilibrium sediment with x-ray densitometry, conforms to the Carnahan-Starling equation. However, the osmotic pressure of the crystalline phase lies slightly above that calculated for a single fcc crystal even after accounting for polydispersity. Likewise the high shear viscosity of the fluid compares well with other hard sphere dispersions, but the low shear viscosity for PMMA-PHSA hard spheres exceeds those for polystyrene and silica hard spheres, e.g., a relative viscosity of 45+/-3 at ?=0.50 rather than 24. Our low shear viscosities are consistent with other PMMA-PHSA data after rescaling for both the polymer layer thickness and polydispersity, and may represent the true hard sphere curve. We anticipate that the equation of state for the crystal deviates due to polycrystallinity or a direct effect of polydispersity.

Phan, See-Eng; Russel, William B.; Cheng, Zhengdong; Zhu, Jixiang; Chaikin, Paul M.; Dunsmuir, John H.; Ottewill, Ronald H.

1996-12-01

375

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

376

Hard and soft acids and bases: atoms and atomic ions.  

PubMed

The structural origin of hard-soft behavior in atomic acids and bases has been explored using a simple orbital model. The Pearson principle of hard and soft acids and bases has been taken to be the defining statement about hard-soft behavior and as a definition of chemical hardness. There are a number of conditions that are imposed on any candidate structure and associated property by the Pearson principle, which have been exploited. The Pearson principle itself has been used to generate a thermodynamically based scale of relative hardness and softness for acids and bases (operational chemical hardness), and a modified Slater model has been used to discern the electronic origin of hard-soft behavior. Whereas chemical hardness is a chemical property of an acid or base and the operational chemical hardness is an experimental measure of it, the absolute hardness is a physical property of an atom or molecule. A critical examination of chemical hardness, which has been based on a more rigorous application of the Pearson principle and the availability of quantitative measures of chemical hardness, suggests that the origin of hard-soft behavior for both acids and bases resides in the relaxation of the electrons not undergoing transfer during the acid-base interaction. Furthermore, the results suggest that the absolute hardness should not be taken as synonymous with chemical hardness but that the relationship is somewhat more complex. Finally, this work provides additional groundwork for a better understanding of chemical hardness that will inform the understanding of hardness in molecules. PMID:18510287

Reed, James L

2008-07-01

377

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

378

Hard X-ray Microscopic Images of the Human Hair  

NASA Astrophysics Data System (ADS)

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; Yon, Hwa Shik; Lee, Won-Soo

2007-01-01

379

Transversity in hard exclusive electroproduction of pseudoscalar mesons  

E-print Network

Estimates for electroproduction of pseudoscalar mesons at small values of skewness are presented. Cross sections and asymmetries for these processes are calculated within the handbag approach which is based on factorization in hard parton subprocesses and soft generalized parton distributions (GPDs). The latter are constructed from double distributions. Transversity GPDs are taken into account; they are accompanied by twist-3 meson wave functions. For most pseudoscalar-meson channels a combination of H-tilde_T$ and E-bar_T$ plays a particularly prominent role. This combination of GPDs which we constrain by moments obtained from lattice QCD, leads with the exception of the pi+ and eta' channels, to large transverse cross sections.

S. V. Goloskokov; P. Kroll

2011-06-24

380

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

381

Density functional theory for colloidal mixtures of hard platelets, rods, and spheres  

E-print Network

A geometry-based density functional theory is presented for mixtures of hard spheres, hard needles and hard platelets; both the needles and the platelets are taken to be of vanishing thickness. Geometrical weight functions that are characteristic for each species are given and it is shown how convolutions of pairs of weight functions recover each Mayer bond of the ternary mixture and hence ensure the correct second virial expansion of the excess free energy functional. The case of sphere-platelet overlap relies on the same approximation as does Rosenfeld's functional for strictly two-dimensional hard disks. We explicitly control contributions to the excess free energy that are of third order in density. Analytic expressions relevant for the application of the theory to states with planar translational and cylindrical rotational symmetry, e.g. to describe behavior at planar smooth walls, are given. For binary sphere-platelet mixtures, in the appropriate limit of small platelet densities, the theory differs from that used in a recent treatment [L. Harnau and S. Dietrich, Phys. Rev. E 71, 011504 (2004)]. As a test case of our approach we consider the isotropic-nematic bulk transition of pure hard platelets, which we find to be weakly first order, with values for the coexistence densities and the nematic order parameter that compare well with simulation results.

Ansgar Esztermann; Hendrik Reich; Matthias Schmidt

2005-11-18

382

Effect of water hardness on the production and microbicidal efficacy of slightly acidic electrolyzed water.  

PubMed

Slightly acidic electrolyzed water (SAEW) has been proved as an effective sanitizer against microorganisms attached to foods. However, its physical properties and inactivation efficacy are affected by several factors such as water hardness. Therefore, in this study the effect of water hardness on SAEW properties were studied. Pure cultures of foodborne bacteria were used in vitro and in vivo to evaluate the inactivation efficacy of the SAEWs produced. Results obtained showed water hardness to be an important factor in the production of SAEW. Low water hardness may result in the necessity of further optimization of production process. In this study the addition of 5% HCl and 2 M NaCl at 1.5 mL/min flow rate was found to be the best electrolyte concentration for the optimization of SAEW production from low hardness water (34 ± 2 mg/L). Furthermore, the results showed that pre-heating was a better approach compared to post-production heating of SAEW, resulting in higher ACC values and therefor better sanitization efficacy. PMID:25790988

Forghani, Fereidoun; Park, Joong-Hyun; Oh, Deog-Hwan

2015-06-01

383

Bonded hard-sphere (BHS) theory for the equation of state of fused hard-sphere polyatomic molecules and their mixtures  

NASA Astrophysics Data System (ADS)

The bonded hard-sphere (BHS) approach originally developed for diatomic and triatomic molecules is generalized to hard-sphere polyatomic models which are formed by bonding together their constituent hard spheres. The thermodynamic properties of the polyatomic fluid are obtained from the known properties of a corresponding multicomponent mixture of different sized hard spheres with bonding sites. In the limit of complete bonding, hard-sphere polyatomic molecules are formed. As well as the general expressions for polyatomic molecules and their mixtures, the equation of state of hard-sphere chain molecules, which are simple models of homologous series such as the alkanes, perfluoroalkanes, etc., is presented. More specifically, the chain molecules are formed from two different types of hard spheres 1 and 2. Spheres of type 1 make up the backbone of the chain and, in this case, would represent the carbon atoms; spheres of type 2 represent the substituents, i.e., the hydrogen or fluorine atoms. Although the BHS theory is only strictly valid for molecules of tangent spheres, the theory can also be applied to fused hard-sphere (FHS) molecules with overlapping spheres. The latter are more realistic models of actual molecules. In the spirit of the semiempirical scaled particle theories (SPT), the properties of the FHS molecule can be related to those of an equivalent BHS molecule of tangent spheres with the same parameter of nonsphericity, ?. When dealing with large polyatomic molecules, ? does not need to be calculated numerically as is the case with the usual SPT approach. As an approximation one may use the analytical values of ? for the diatomic segments making up the molecule. This simple approach turns out to be quite successful. The BHS equation of state has been compared with ``exact'' computer simulation data for homonuclear and heteronuclear FHS systems of diatomics, linear and nonlinear triatomics, and tetrahedral pentatomics, as well as mixtures of FHS molecules. Good agreement is found for all of these systems. In general, the BHS approach is more rigorous and easier to extend to larger polyatomic molecules and their mixtures than SPT.

Amos, Michael D.; Jackson, George

1992-03-01

384

The Value Relevance of Fair Value  

Microsoft Academic Search

This paper investigates the value relevance of revalued tangible assets and its variation depending on industry, size of the\\u000a firm and age of revalued amounts. It examines the reaction of investors on the Romanian market, a developing market, in the\\u000a period of economic growth between 2003 and 2007, before Romania’s adherence to the European Union. Also, it suggests a model

Adela Deaconu; Anu?a Buiga; Cristina Silvia Nistor

2010-01-01

385

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

386

Hardness of Preorder Checking for Basic Formalisms  

NASA Astrophysics Data System (ADS)

We investigate the complexity of preorder checking when the specification is a flat finite-state system whereas the implementation is either a non-flat finite-state system or a standard timed automaton. In both cases, we show that simulation checking is Exptime-hard, and for the case of a non-flat implementation, the result holds even if there is no synchronization between the parallel components and their alphabets of actions are pairwise disjoint. Moreover, we show that the considered problems become Pspace-complete when the specification is assumed to be deterministic. Additionally, we establish that comparing a synchronous non-flat system with no hiding and a flat system is Pspace-hard for any relation between trace containment and bisimulation equivalence.

Bozzelli, Laura; Legay, Axel; Pinchinat, Sophie

387

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

388

Laser thermographic technologies for hard copy recording  

NASA Astrophysics Data System (ADS)

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

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

1995-04-01

389

Hardness/intensity correlations among BATSE bursts  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

390

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

391

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

392

Unraveling Quantum Annealers using Classical Hardness  

E-print Network

Recent advances in quantum technology have led to the development and manufacturing of experimental programmable quantum annealing optimizers that contain hundreds of quantum bits. These optimizers, named `D-Wave' chips, promise to solve practical optimization problems potentially faster than conventional `classical' computers. Attempts to quantify the quantum nature of these chips have been met with both excitement and skepticism but have also brought up numerous fundamental questions pertaining to the distinguishability of quantum annealers from their classical thermal counterparts. Here, we propose a general method aimed at answering these, and apply it to experimentally study the D-Wave chip. Inspired by spin-glass theory, we generate optimization problems with a wide spectrum of `classical hardness', which we also define. By investigating the chip's response to classical hardness, we surprisingly find that the chip's performance scales unfavorably as compared to several analogous classical algorithms. We detect, quantify and discuss purely classical effects that possibly mask the quantum behavior of the chip.

Victor Martin-Mayor; Itay Hen

2015-02-09

393

MATERIALS CHARACTERISATION Material properties such as strength, toughness or hardness  

E-print Network

. Strength, toughness or hardness, which are determined by the chemical composition and thermal treatmentMATERIALS CHARACTERISATION Material properties such as strength, toughness or hardness are usually (shear and longitudinal). However, strength or hardnesscannotbedetermineddirectlyfromthoseparameters

394

Harry Harding Auditorium Elliott School of International Affairs  

E-print Network

Harry Harding Auditorium Elliott School of International Affairs 1957 E Street, NW, Washington, DC-Sook Colloquium: Saturday, Nov. 5, 2011 8:45 am - 3:30 pm Harry Harding Auditorium Elliott School of International

Schmitt, William R.

395

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

396

Virial series for fluids of hard hyperspheres in odd dimensions  

E-print Network

A recently derived method [R. D. Rohrmann and A. Santos, Phys. Rev. E. {\\bf 76}, 051202 (2007)] to obtain the exact solution of the Percus-Yevick equation for a fluid of hard spheres in (odd) $d$ dimensions is used to investigate the convergence properties of the resulting virial series. This is done both for the virial and compressibility routes, in which the virial coefficients $B_j$ are expressed in terms of the solution of a set of $(d-1)/2$ coupled algebraic equations which become nonlinear for $d \\geq 5$. Results have been derived up to $d=13$. A confirmation of the alternating character of the series for $d\\geq 5$, due to the existence of a branch point on the negative real axis, is found and the radius of convergence is explicitly determined for each dimension. The resulting scaled density per dimension $2 \\eta^{1/d}$, where $\\eta$ is the packing fraction, is wholly consistent with the limiting value of 1 for $d \\to \\infty$. Finally, the values for $B_j$ predicted by the virial and compressibility routes in the Percus-Yevick approximation are compared with the known exact values [N. Clisby and B. M. McCoy, J. Stat. Phys. {\\bf 122}, 15 (2006)

Rene D. Rohrmann; Miguel Robles; Mariano Lopez de Haro; Andres Santos

2008-04-29

397

GLUON RADIATION PATTERNS IN HARD SCATTERING EVENTS  

E-print Network

The radiation pattern of relatively soft gluons in hard scattering events is sensitive to the underlying color structure. As an example I consider heavy Higgs production via weak boson fusion at the LHC. A minijet veto, which makes use of the different patterns for signal and backgrounds, provides an effective Higgs search tool. Talk presented at the Conference on Physics {\\it Beyond the Standard Model IV}, Lake Tahoe, California, December 14--18, 1994.

Dieter Zeppenfeld

1995-03-14

398

Rad-Hard/HI-REL FPGA  

NASA Technical Reports Server (NTRS)

The goals for a radiation hardened (RAD-HARD) and high reliability (HI-REL) field programmable gate array (FPGA) are described. The first qualified manufacturer list (QML) radiation hardened RH1280 and RH1020 were developed. The total radiation dose and single event effects observed on the antifuse FPGA RH1280 are reported on. Tradeoffs and the limitations in the single event upset hardening are discussed.

Wang, Jih-Jong; Cronquist, Brian E.; McGowan, John E.; Katz, Richard B.

1997-01-01

399

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

400

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

401

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

402

Checking robust nonsingularity is NP-hard  

Microsoft Academic Search

We consider the following problem: givenk+1 square matrices with rational entries,A0,A1,...,Ak, decide ifA0+r1A1+···+rkAk is nonsingular for all possible choices of real numbersr1, ...,rk in the interval [0, 1]. We show that this question, which is closely related to the robust stability problem, is NP-hard. The proof relies on the new concept ofradius of nonsingularity of a square matrix and on

Svatopluk Poljak; Ji?í Rohn

1993-01-01

403

Dynamic Hardness Tester and Cure Meter  

NASA Technical Reports Server (NTRS)

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

Madigosky, Walter M.; Fiorito, Ralph B.

1993-01-01

404

MICROMEGAS: High rate and radiation hardness results  

SciTech Connect

In this report, the authors present results of gain studies using various gas mixtures in a novel structure of gaseous detector called MICROMEGAS which is under development at Saclay. The authors in particular studied the maximum of gain achievable with MICROMEGAS before the discharge. They tried various gas mixtures (Argon, Neon, CF{sub 4}) with various proportions of quencher (Isobutane, Cyclohexane, DME). They also studied the radiation hardness of MICROMEGAS using Argon-Isobutane and CF{sub 4}-Isobutane mixtures.

Puill, G.; Derre, J.; Giomataris, Y.; Rebourgeard, P.

1999-12-01

405

Characterization of hard-edge diffracted beams  

Microsoft Academic Search

A liquid nitrogen cooled high precision CCD camera is used for a systematic investigation of the propagation properties of hard edge diffracted beams. The diffraction effects are generated by propagating a nearly Gaussian beam (K equals 0.98, lambda equals 632.8 nm) through circular apertures of different sizes. The apertures are chosen so that 1.5%, 5.9% and 14.1% of the total

R. Maestle; Adolf Giesen

1996-01-01

406

Solving the hard problem of Bertrand's paradox  

SciTech Connect

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.

Aerts, Diederik, E-mail: diraerts@vub.ac.be [Center Leo Apostel for Interdisciplinary Studies and Department of Mathematics, Brussels Free University, Brussels (Belgium); Sassoli de Bianchi, Massimiliano, E-mail: autoricerca@gmail.com [Laboratorio di Autoricerca di Base, Lugano (Switzerland)

2014-08-15

407

Hard diffraction and deep inelastic scattering  

SciTech Connect

Since the advent of hard-collision physics, the study of diffractive processes - shadow physics - has been less prominent than before. However, there is now a renewed interest in the subject, especially in that aspect which synthesizes the short-distance, hard-collision phenomena with the classical physics of large rapidity-gaps. This is especially stimulated by the recent data on deep-inelastic scattering from HERA, as well as the theoretical work which relates to it. The word diffraction is sometimes used by high-energy physicists in a loose way. The author defines this term to mean: A diffractive process occurs if and only if there is a large rapidity gap in the produced-particle phase space which is not exponentially suppressed. Here a rapidity gap means essentially no hadrons produced into the rapidity gap (which operates in the {open_quotes}lego{close_quotes} phase-space of pseudo-rapidity and azimuthal angle). And non-exponential suppression implies that the cross-section for creating a gap with width {Delta}{eta} does not have a power-law decrease with increasing subenergy s=e{sup {Delta}{eta}}, but behaves at most like some power of pseudorapidity {Delta}{eta}{approx}log(s). The term hard diffraction shall simply refer to those diffractive process which have jets in the final-state phase-space.

Bjorken, J.D.

1994-04-01

408

Hard hadronic collisions: extrapolation of standard effects  

SciTech Connect

We study hard hadronic collisions for the proton-proton (pp) and the proton-antiproton (p anti p) option in the CERN LEP tunnel. Based on our current knowledge of hard collisions at the present CERN p anti p Collider, and with the help of quantum chromodynamics (QCD), we extrapolate to the next generation of hadron colliders with a centre-of-mass energy E/sub cm/ = 10 to 20 TeV. We estimate various signatures, trigger rates, event topologies, and associated distributions for a variety of old and new physical processes, involving prompt photons, leptons, jets, W/sup + -/ and Z bosons in the final state. We also calculate the maximum fermion and boson masses accessible at the LEP Hadron Collider. The standard QCD and electroweak processes studied here, being the main body of standard hard collisions, quantify the challenge of extracting new physics with hadron colliders. We hope that our estimates will provide a useful profile of the final states, and that our experimental physics colleagues will find this of use in the design of their detectors. 84 references.

Ali, A.; Aurenche, P.; Baier, R.; Berger, E.; Douiri, A.; Fontannaz, M.; Humpert, B.; Ingelman, G.; Kinnunen, R.; Pietarinen, E.

1984-01-01

409

Characterization of Radiation Hard Silicon Materials  

SciTech Connect

Segmented silicon detectors are widely used in modern high-energy physics (HEP) experiments due to their excellent spatial resolution and well-established manufacturing technology. However, in such experiments the detectors are exposed to high fluences of particle radiation, which causes irreversible crystallographic defects in the silicon material. Since 1990's, considerable amount of research has gone into improving the radiation hardness of silicon detectors. One very promising approach is to use magnetic Czochralski silicon (MCz-Si) that has been found to be more radiation hard against charged hadrons than traditional Float Zone silicon material (Fz-Si) used in the current HEP applications. Other approaches include operating the devices at cryogenic temperatures and designing special detector structures such as p-type detectors or semi-3D detectors. In order to demonstrate that the developed technologies are suitable for the HEP experiments, it is necessary to extensively characterize the potentially radiation hard detectors. We have an excellent instrument for this, the Cryogenic Transient Current Technique (C-TCT) measurement setup, which is an effective research tool for studying heavily irradiated silicon detectors. With the C-TCT setup it is possible to extract the full depletion voltage, effective trapping time, electric field distribution and the sign of the space charge in the silicon bulk in the temperature range of 45-300 K. This articles presents a description of this setup and measurement results from detectors processed of MCz-Si.

Luukka, P.; Li, Z.; J. Harkonen, E. Tuovinen, S. Czellar, V. Eremin, E. Tuominen, E. Verbitskaya

2009-02-24

410

February 24, 2009 Radiation-Hardness of VCSEL/PIN  

E-print Network

February 24, 2009 Radiation-Hardness of VCSEL/PIN W. Fernando, K.K. Gan, H.P. Kagan, R.D. Kass, J Introduction Radiation hardness of PINs Radiation hardness of VCSELs Summary #12;K.K. Gan ATLAS Upgrade with 50% safety factor #12;K.K. Gan ATLAS Upgrade Week 5 K.K. Gan 5 Radiation-Hardness of Silicon PIN

Gan, K. K.

411

Algorithms for sparse analysis Lecture II: Hardness results for sparse  

E-print Network

Algorithms for sparse analysis Lecture II: Hardness results for sparse approximation problems Anna's polynomial time computable function f s.t. w A f (w) B. · B at least as hard as A #12;Complexity theory: NP-hard · Definition A NP-complete if (i) A NP and (ii) for all X NP, X P A. · Definition B NP-hard

412

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

413

Influence of Nitrogen Flow Rates on the Structure, Hardness, and Electrical Resistivity of HfN Coatings by DC Sputtering  

NASA Astrophysics Data System (ADS)

HfN hard coatings on Corning glass substrates were obtained using DC sputtering. A power of 200 W was used keeping the flow rate of argon at 10 sccm and varying the nitrogen flow rates at 2.5, 3.5, 5.0, and 7.5 sccm to analyze differences in the hardness and electrical resistivity values, explaining variations in relation to structural changes. To achieve this, the Vickers microhardness test, x-ray diffraction, Raman, atomic force microscopy, and high resistivity measurements were used. At 2.5 sccm, the hardness value was shown to reach a maximum value of 20 GPa, and a minimum electrical resistivity of 6.5 × 108 µ?cm. Furthermore, as the flow is increased, the hardness values gradually decrease (until a value of 8 GPa is reached), the fracture toughness increase (until a value of 0.3 MPa?m is reached), and the electrical resistivity reaches its maximum at 1.52 × 1012 ??cm. These variations are attributed to the evolution that the HfN phase progressively undergoes from a crystal orientation at (111) to an amorphous phase. In addition, the presence of tensile stresses, which tend to favor electrical resistivity, was identified. The average RMS roughness increased from 3.76 to 10.69 nm as the nitrogen flow was increased. Finally, the Raman spectroscopy confirmed the presence of the HfN phase.

García-González, Leandro; Zamora-Peredo, Luis; Flores-Ramírez, Nelly; Garnica-Romo, María Guadalupe; Hernández-Torres, Julián

2015-04-01

414

Influence of Nitrogen Flow Rates on the Structure, Hardness, and Electrical Resistivity of HfN Coatings by DC Sputtering  

NASA Astrophysics Data System (ADS)

HfN hard coatings on Corning glass substrates were obtained using DC sputtering. A power of 200 W was used keeping the flow rate of argon at 10 sccm and varying the nitrogen flow rates at 2.5, 3.5, 5.0, and 7.5 sccm to analyze differences in the hardness and electrical resistivity values, explaining variations in relation to structural changes. To achieve this, the Vickers microhardness test, x-ray diffraction, Raman, atomic force microscopy, and high resistivity measurements were used. At 2.5 sccm, the hardness value was shown to reach a maximum value of 20 GPa, and a minimum electrical resistivity of 6.5 × 108 µ?cm. Furthermore, as the flow is increased, the hardness values gradually decrease (until a value of 8 GPa is reached), the fracture toughness increase (until a value of 0.3 MPa?m is reached), and the electrical resistivity reaches its maximum at 1.52 × 1012 ??cm. These variations are attributed to the evolution that the HfN phase progressively undergoes from a crystal orientation at (111) to an amorphous phase. In addition, the presence of tensile stresses, which tend to favor electrical resistivity, was identified. The average RMS roughness increased from 3.76 to 10.69 nm as the nitrogen flow was increased. Finally, the Raman spectroscopy confirmed the presence of the HfN phase.

García-González, Leandro; Zamora-Peredo, Luis; Flores-Ramírez, Nelly; Garnica-Romo, María Guadalupe; Hernández-Torres, Julián

2015-02-01

415

Evaluation of Vickers hardness and depth of cure of six composite resins photo-activated with different polymerization modes  

PubMed Central

Aim: The current in vitro study evaluated Vickers hardness (VK) and depth of cure (hardness ratio) of six resin composites, polymerized with a light-emitting diode (LED) curing unit by different polymerization modes: Standard 20 s, Standard 40 s, Soft-start 40 s. Materials and Methods: Six resin composites were selected for the present study: three microhybrid (Esthet.X HD, Amaris, Filtek Silorane), two nanohybrid (Grandio, Ceram.X mono) and one nanofilled (Filtek Supreme XT). The VK of the surface was determined with a microhardness tester using a Vickers diamond indenter and a 200 g load applied for 15 seconds. The mean VK and hardness ratio of the specimens were calculated using the formula: hardness ratio = VK of bottom surface / VK of top surface. Results: For all the materials tested and with all the polymerization modes, hardness ratio was higher than the minimum value indicated in literature in order to consider the bottom surface as adequately cured (0.80). Curing time did not affect hardness ratio values for Filtek Silorane, Grandio and Filtek Supreme XT. Conclusion: The effectiveness of cure at the top and bottom surface was not affected by Soft-start polymerization mode. PMID:22876009

Poggio, C; Lombardini, M; Gaviati, S; Chiesa, M

2012-01-01

416

Fate of Mycobacterium avium subsp. paratuberculosis in Swiss Hard and Semihard Cheese Manufactured from Raw Milk  

PubMed Central

Raw milk was artificially contaminated with declumped cells of Mycobacterium avium subsp. paratuberculosis at a concentration of 104 to 105 CFU/ml and was used to manufacture model hard (Swiss Emmentaler) and semihard (Swiss Tisliter) cheese. Two different strains of M. avium subsp. paratuberculosis were tested, and for each strain, two model hard and semihard cheeses were produced. The survival of M. avium subsp. paratuberculosis cells was monitored over a ripening period of 120 days by plating out homogenized cheese samples onto 7H10-PANTA agar. In both the hard and the semihard cheeses, counts decreased steadily but slowly during cheese ripening. Nevertheless, viable cells could still be detected in 120-day cheese. D values were calculated at 27.8 days for hard and 45.5 days for semihard cheese. The most important factors responsible for the death of M. avium subsp. paratuberculosis in cheese were the temperatures applied during cheese manufacture and the low pH at the early stages of cheese ripening. Since the ripening period for these raw milk cheeses lasts at least 90 to 120 days, the D values found indicate that 103 to 104 cells of M. avium subsp. paratuberculosis per g will be inactivated. PMID:11526024

Spahr, U.; Schafroth, K.

2001-01-01

417

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

418

Hard Tissue Formation in Subcutaneously Transplanted Rat Dental Pulp  

Microsoft Academic Search

While dental pulp appears to be able to form mineralized matrices that do not always resemble dentin, the precise characteristics of the hard tissue and the mechanism of its induction remain unknown. Therefore, we evaluated hard tissue induced by transplantation of pulp into subcutaneous tissue. Seven days after transplantation, initial hard tissue was formed at the inner periphery of the

A. Hosoya; H. Nakamura; T. Ninomiya; K. Hoshi; K. Yoshiba; N. Yoshiba; M. Takahashi; T. Okabe; N. Sahara; H. Yamada; E. Kasahara; H. Ozawa

2007-01-01

419

Uniform Hardness Amplification in NP via Monotone Codes  

E-print Network

Uniform Hardness Amplification in NP via Monotone Codes Joshua Buresh-Oppenheim Valentine Kabanets,kabanets,rsanthan}@cs.sfu.ca December 4, 2006 Abstract We consider the problem of amplifying uniform average-case hardness of languages in NP, where hardness is with respect to BPP algorithms. We introduce the notion of monotone error

Kabanets, Valentine

420

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

421

Hard Real-Time Programming is Different Peter Puschner  

E-print Network

Hard Real-Time Programming is Different £ Peter Puschner Institut f¨ur Technische Informatik requirements imposed on (hard) real- time code resp. non real-time code differ. As a consequence, conventional coding strategies as used to develop non real- time software are not suited for hard real-time code

422

Hardness of the Covering Radius Problem on Lattices Ishay Haviv  

E-print Network

Hardness of the Covering Radius Problem on Lattices Ishay Haviv Oded Regev June 6, 2006 Abstract We provide the first hardness result for the Covering Radius Problem on lattices (CRP). Namely, we show that for any large enough p there exists a constant cp > 1 such that CRP in the p norm is 2-hard

Regev, Oded

423

Texts in Computational Complexity: Ampli cation of Hardness  

E-print Network

Texts in Computational Complexity: Ampli cation of Hardness Oded Goldreich Department of Computer a positive side, because hard problem can be \\put to work" to our bene t, most notably in cryptography. One key issue that arises whenever one tries to utilize hard problem is bridging the gap between

Goldreich, Oded

424

Uniform Hardness Amplification in NP via Monotone Codes  

E-print Network

Uniform Hardness Amplification in NP via Monotone Codes Joshua Buresh­Oppenheim Valentine Kabanets,kabanets,rsanthan}@cs.sfu.ca December 4, 2006 Abstract We consider the problem of amplifying uniform average­case hardness of languages in NP, where hardness is with respect to BPP algorithms. We introduce the notion of monotone error

Penn, Gerald

425

Hardness Amplification within NP against Deterministic Algorithms Parikshit Gopalan  

E-print Network

Hardness Amplification within NP against Deterministic Algorithms Parikshit Gopalan University We study the average-case hardness of the class NP against deterministic polynomial time algorithms Introduction The average case hardness of complexity classes such as EXP and NP has been studied intensively

Guruswami, Venkatesan

426

Hard or Soft Classification? Large-Margin Unified Machines  

E-print Network

Hard or Soft Classification? Large-Margin Unified Machines Yufeng LIU, Hao Helen ZHANG, and Yichao for classification problems. Among numerous classifiers, some are hard classifiers while some are soft ones. Soft on estimated probabilities. In contrast, hard classifiers directly target the classification decision boundary

Liu, Yufeng

427

Hard instances of algorithms and proof systems Yijia Chen1  

E-print Network

Hard instances of algorithms and proof systems Yijia Chen1 , J¨org Flum2 , and Moritz M¨uller3 1 Hypothesis there is a problem which has no almost optimal algorithm but has an algorithm without hard is hard for A if it is computable in polynomial time and the sequence (tA(xs)sN) is not polynomially

Chen, Yijia

428

Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm  

E-print Network

#12;Hard Bottom Substrate Monitoring Horns Rev Offshore Wind Farm 2004 Survey Report No. 1 March : Simon B. Leonhard #12;Horns Rev. Hard Bottom Substrate Monitoring 2004 Survey Report No. 1. Page 3 Doc ........................................................................................................................ 15 #12;Horns Rev. Hard Bottom Substrate Monitoring 2004 Survey Report No. 1. Page 4 Doc. No. 2438

429

Hard and soft locking Andrew Knyazev, CU-Denver  

E-print Network

Hard and soft locking Andrew Knyazev, CU-Denver 1 Center for Computational Mathematics, University of Colorado at Denver Hard and soft locking in iterative methods for symmetric eigenvalue problems Andrew V) This material is based upon work supported by the NSF #12;Hard and soft locking Andrew Knyazev, CU-Denver 2

Knyazev, Andrew

430

Aperiodic Task Scheduling for Hard Real-Time Systems  

Microsoft Academic Search

 A real-time system consists of both aperiodic and periodic tasks. Periodic tasks have regular arrival times and hard deadlines. Aperiodic tasks have irregular arrival times and either soft or hard deadlines. In this article, we present a new algorithm, the Sporadic Server algorithm, which greatly improves response times for soft deadline aperiodic tasks and can guarantee hard deadlines for both

Brinkley Sprunt; Lui Sha; John P. Lehoczky

1989-01-01

431

A Bayesian Approach to Hardness Ratios for non-Bayesians  

E-print Network

A Bayesian Approach to Hardness Ratios for non-Bayesians John E. Davis @space.mit.edu> December 18, 2007 1 Introduction Hardness ratios are often used in situations where there may not be enough. The computation of confidence limits for hardness ratios has been addressed by others ([Park et al.(2006), Jin et

Davis, John E.

432

Hardness vs. Randomness within Alternating Time Emanuele Viola  

E-print Network

Hardness vs. Randomness within Alternating Time Emanuele Viola Division of Engineering and Applied of building pseudorandom generators (PRGs) with logarithmic seed length from hard functions. We show that, starting from a func- tion f : {0, 1}l {0, 1} that is mildly hard on av- erage, i.e. every circuit of size

Viola, Emanuele

433

Hardness vs. Randomness within Alternating Time Emanuele Viola #  

E-print Network

Hardness vs. Randomness within Alternating Time Emanuele Viola # Division of Engineering the complexity of building pseudorandom generators (PRGs) with logarithmic seed length from hard functions. We show that, starting from a func­ tion f : {0, 1} l # {0, 1} that is mildly hard on av­ erage, i

Viola, Emanuele

434

EFFECT OF ION BEAM IRRADIATION ON HARDNESS OF POLYETHYLENE TEREPHTHALATE  

Microsoft Academic Search

Ion beam irradiation as one of the effective methods of polymer modification has been used on the PET films. The ion beam used was Li(50 MeV) of various fluences. The Vickers' hardness of the films irradiated at different ion fluences was measured. The hardness tests on each film were carried out at different loads. The true bulk hardness of the film

N. L. Singh; C. F. Desai; N. Shah; P. H. Soni; V. Shrinet; D. K. Avasthi

2002-01-01

435

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

436

Fault-Tolerant, Radiation-Hard DSP  

NASA Technical Reports Server (NTRS)

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

Czajkowski, David

2011-01-01

437

The Value Chain  

NSDL National Science Digital Library

From Industry Week, The Value Chain is an online publication providing up-to-date information, articles, and resources on value chain management (VCM), a theory of management that considers every step of manufacturing a product, from raw materials "right down to disposing of the packaging after use." Along with feature articles and columns about value chain management, the site also contains a FAQ, which offers excellent basic advice about VCM, a New Roundup Weblog of breaking VCM news, and short research pieces.

438

J.M. Carroll -"Soft versus hard: The essential tension?" 1 Soft versus Hard: The essential tension  

E-print Network

the people and #12;J.M. Carroll - "Soft versus hard: The essential tension?" 2 organizations that useJ.M. Carroll - "Soft versus hard: The essential tension?" 1 Soft versus Hard: The essential tension skill through more sophisticated cognitive theories, through extending attention to non

Carroll, John M.

439

Ultrasonically bonded value assembly  

NASA Technical Reports Server (NTRS)

A valve apparatus capable of maintaining a fluid-tight seal over a relatively long period of time by releasably bonding a valve member to its seat is described. The valve member is bonded or welded to the seat and then released by the application of the same energy to the bond joint. The valve member is held in place during the bonding by a clamping device. An appropriate force device can activate the opening and closing of the valve member. Various combinations of material for the valve member and valve seat can be utilized to provide an adequate sealing bond. Aluminum oxide, stainless steel, inconel, tungsten carbide as hard materials and copper, aluminum, titanium, silver, and gold as soft materials are suggested.

Salvinski, R. J. (inventor)

1975-01-01

440

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

441

Fair Value Accounting  

Microsoft Academic Search

The presentation examines the shifting landscape of financial reporting and the long-term implications of the introduction of new requirements for accountants to incorporate fair value information in financial statements and to assess fair value amounts of reported assets and liabilities.

Tan Hock Neo Pearl

2004-01-01

442

Value-centred HCI  

Microsoft Academic Search

HCI is misdefined. We need to redefine it. HCI is misfocused. We need to refocus it. HCI has a window of opportunity to recreate itself as a design discipline. It must focus on the intention of gifted design, which is to improve the world by delivering new sources of value. A focus on value creates a paradoxical discipline that fuses

Gilbert Cockton

2004-01-01

443

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.

444

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

445

Work Values across Generations  

ERIC Educational Resources Information Center

Mainstream publication discussions of differences in generational cohorts in the workplace suggest that individuals of more recent generations, such as Generation X and Y, have different work values than do individuals of the Silent and Baby Boom generations. Although extant research suggests that age may influence work values, few of the…

Hansen, Jo-Ida C.; Leuty, Melanie E.

2012-01-01

446

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

447

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

448

Cognitive and Social Values.  

ERIC Educational Resources Information Center

Criticizes Hugh Lacey's separation of cognitive values and social values in discussions of the nature of science. Claims that attempting to distinguish between cognitive and social ignores crucial complexities in the development and use of knowledge. Proposes that the proper distinction be between legitimate and illegitimate reasons in science as…

Machamer, Peter; Douglas, Heather

1999-01-01

449

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

450

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.

451

Decimal Place Value  

NSDL National Science Digital Library

Students learn about decimal place value and the relationship between tenths, hundredths, and thousandths. Students will explore decimal place value, read and write decimals using tenths, hundredths, and thousandths, and compare decimals using greater-than and less-than notation.

Teacher Vision

2012-08-02

452

A multi-step system for screening and localization of hard exudates in retinal images  

NASA Astrophysics Data System (ADS)

The number of people being affected by Diabetes mellitus worldwide is increasing at an alarming rate. Monitoring of the diabetic condition and its effects on the human body are therefore of great importance. Of particular interest is diabetic retinopathy (DR) which is a result of prolonged, unchecked diabetes and affects the visual system. DR is a leading cause of blindness throughout the world. At any point of time 25 - 44% of people with diabetes are afflicted by DR. Automation of the screening and monitoring process for DR is therefore essential for efficient utilization of healthcare resources and optimizing treatment of the affected individuals. Such automation would use retinal images and detect the presence of specific artifacts such as hard exudates, hemorrhages and soft exudates (that may appear in the image) to gauge the severity of DR. In this paper, we focus on the detection of hard exudates. We propose a two step system that consists of a screening step that classifies retinal images as normal or abnormal based on the presence of hard exudates and a detection stage that localizes these artifacts in an abnormal retinal image. The proposed screening step automatically detects the presence of hard exudates with a high sensitivity and positive predictive value (PPV ). The detection/localization step uses a k-means based clustering approach to localize hard exudates in the retinal image. Suitable feature vectors are chosen based on their ability to isolate hard exudates while minimizing false detections. The algorithm was tested on a benchmark dataset (DIARETDB1) and was seen to provide a superior performance compared to existing methods. The two-step process described in this paper can be embedded in a tele-ophthalmology system to aid with speedy detection and diagnosis of the severity of DR.

Bopardikar, Ajit S.; Bhola, Vishal; Raghavendra, B. S.; Narayanan, Rangavittal

2012-03-01

453

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

454

[Occupational asthma due to hard metals hypersensitivity].  

PubMed

The authors report the case of a worker in the hard metal industry presenting with asthma due to cobalt and nickel. The diagnosis was supported by the history, positive skin tests and lymphocyte activation as well as elevated levels of the metals in the urine and BAL. Challenge led to a delayed asthmatic reaction occurring 3.5 to 24 hours after exposure. The BAL contained high levels of tungsten and cobalt, the level of the latter doubling 48 hours after exposure. After the provocation test a nasal and broncho-alveolar eosinophilia was observed. The possibility of a delayed hypersensitivity reaction to metals is discussed by the authors. PMID:12161703

De Hauteclocque, C; Morisset, M; Kanny, G; Kohler, C; Mouget, B; Moneret-Vautrin, D A

2002-06-01

455

Evolutionary algorithms for hard quantum control  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

456

Nonvolatile Rad-Hard Holographic Memory  

NASA Technical Reports Server (NTRS)

We are investigating a nonvolatile radiation-hardened (rad-hard) holographic memory technology. Recently, a compact holographic data storage (CHDS) breadboard utilizing an innovative electro-optic scanner has been built and demonstrated for high-speed holographic data storage and retrieval. The successful integration of this holographic memory breadboard has paved the way for follow-on radiation resistance test of the photorefractive (PR) crystal, Fe:LiNbO3. We have also started the investigation of using two-photon PR crystals that are doubly doped with atoms of iron group (Ti, Cr, Mn, Cu) and of rare-earth group (Nd, Tb) for nonvolatile holographic recordings.

Chao, Tien-Hsin; Zhou, Han-Ying; Reyes, George; Dragoi, Danut; Hanna, Jay

2001-01-01

457

Hard gamma ray emission from blazars  

NASA Technical Reports Server (NTRS)

The gamma-ray emission expected from compact extragalactic sources of nonthermal radiation is examined. The highly variable objects in this class should produce copious amounts of self-Compton gamma-rays in the compact relativistic jet. This is shown to be a likely interpretation of the hard gamma-ray emission recently detected from the quasar 3C 279 during a period of strong nonthermal flaring at lower frequencies. Ways of discriminating between the self-Compton model and other possible gamma-ray emission mechanisms are discussed.

Marscher, Alan P.; Bloom, Steven D.

1992-01-01

458

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

459

Hard Exclusive ?^0-Meson Production at COMPASS  

E-print Network

New results for the transverse target spin azimuthal asymmetry A_{UT}^{sin(\\phi-\\phi_S)} for hard exclusive \\rho^0-meson production on a transversely polarised ^6LiD and NH_3 target will be presented. The measurement was performed with the COMPASS detector using the 160 GeV/c muon beam of the SPS at CERN. The asymmetry is sensitive to the nucleon helicity-flip generalised parton distribution E, which is related to the orbital angular momentum of quarks in the nucleon.

H. Wollny for the COMPASS collaboration

2012-05-30

460

The bounce hardness index of gravitational waves  

E-print Network

We present a method of mode analysis to search for signals with frequency evolution and limited duration in a given data stream. Our method is a natural expansion of the Fourier analysis, and we can obtain the information about frequency evolution with high frequency precision and high time resolution. Applications of this method to the analysis of inspiral and burst signals show that the signals are characterized by an index which we name `bounce hardness'. The index corresponds to the growth rate of the signals.

Fumihiko Ishiyama; Ryutaro Takahashi

2010-12-06

461

Hard pion bremsstrahlung in the Coulomb region  

E-print Network

Hard high-energy pion-nucleus bremsstrahlung, $\\pi^- +A\\to\\pi^- +\\gamma +A$, is studied in the Coulomb region, i.e. the small-angle region where the nuclear scattering is dominated by the Coulomb interaction. Special attention is focussed on the possibility of measuring the pion polarizability in such reactions. We study the sensitivity to the structure of the underlying the pion-Compton amplitude through a model with $\\sigma$, $\\rho$, and a_1 exchanges. It is found that the effective energy in the virtual pion-Compton scattering is often so large that the threshold approximation does not apply.

Göran Fäldt; Ulla Tengblad

2007-08-02

462

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

463

Confinement of hot, hard x-ray producing electrons in solar flares  

Microsoft Academic Search

Possible thermal models for solar, hard X-ray emission, consisting of small volumes in which the electrons are rapidly heated to 4 x 10⁸ K, are examined to determine under what conditions such models can be more efficient than nonthermal models. The primary energy-loss mechanism in these models is source expansion due to heat conduction which deviates from its classical value

D. F. Smith; C. G. Lilliequist

1979-01-01

464

Comparison of structure and transport properties of concentrated hard and soft sphere fluids  

E-print Network

Using Newtonian and Brownian dynamics simulations, the structural and transport properties of hard and soft spheres have been studied. The soft spheres were modeled using inverse power potentials ($V\\sim r^{-n}$, with $1/n$ the potential softness). Although the pressure, diffusion coefficient and viscosity depend at constant density on the particle softness up to extremely high values of $n$, we show that scaling the density with the freezing point for every system effectively collapses these parameters for $n\\geq 18$ (including hard spheres), for large densities. At the freezing points, the long range structure of all systems is identical, when the distance is measured in units of the interparticle distance, but differences appear at short distances (due to the different shape of the interaction potential). This translates into differences at short times in the velocity and stress autocorrelation functions, although they concur to give the same value of the corresponding transport coefficient (for the same density to freezing ratio); the microscopic dynamics also affects the short time behaviour of the correlation functions and absolute values of the transport coefficients, but the same scaling with the freezing density works for Newtonian or Brownian dynamics. For hard spheres, the short time behaviour of the stress autocorrelation function has been studied in detail, confirming quantitatively the theoretical forms derived for it.

Erik Lange; Jose B. Caballero; Antonio M. Puertas; Matthias Fuchs

2009-01-16

465

Improving extreme value statistics  

NASA Astrophysics Data System (ADS)

The rate of convergence in extreme value statistics is nonuniversal and can be arbitrarily slow. Further, the relative error can be unbounded in the tail of the approximation, leading to difficulty in extrapolating the extreme value fit beyond the available data. We introduce the T method, and show that by using simple nonlinear transformations the extreme value approximation can be rendered rapidly convergent in the bulk, and asymptotic in the tail, thus fixing both issues. The transformations are often parametrized by just one parameter, which can be estimated numerically. The classical extreme value method is shown to be a special case of the proposed method. We demonstrate that vastly improved results can be obtained with almost no extra cost.

Shekhawat, Ashivni

2014-11-01

466

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.

National Security Agency Central Security Service

2009-05-19

467

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

468

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

469

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

470

Working with Missing Values  

ERIC Educational Resources Information Center

Less than optimum strategies for missing values can produce biased estimates, distorted statistical power, and invalid conclusions. After reviewing traditional approaches (listwise, pairwise, and mean substitution), selected alternatives are covered including single imputation, multiple imputation, and full information maximum likelihood…

Acock, Alan C.

2005-01-01

471

The Expanding Place Value  

NSDL National Science Digital Library

This collection of three lesson plans is designed to provide students with practice understanding place value (0 to 999), using standard and word form to represent numbers, and using expanded form to represent place value. Each lesson plan provides activities that will help build student understanding of the concepts and practice to help reinforce the skill. Thirteen resource sheets are included and can be used with these lessons or as independent activities.

Erin Thomson

2005-01-01

472

Bhutan National Values Assessment  

E-print Network

, respect for our culture and traditions, love for our country and for God. Throughout our history our parents have upheld these values and placed the common good above the self. My deepest concern is that as the world changes we may lose... indicate alignment. The greater the number of matching current and desired culture values, the greater the degree to which citizens believe their nation is on the right Journal for Bhutan Studies 108 track. In a highly aligned culture, one would expect...

Evans, Steve

2008-01-01

473

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.

474

Hard Color Coherent Phenomena in Dis  

NASA Astrophysics Data System (ADS)

We review two new types of hard diffractive processes calculable in QCD: exclusive production of light mesons in the Bjorken limit by longitudinal photons [1-3], exclusive photo and electro production of heavy onium states [2,4], and diffraction of pions (protons) off nucleons into two (three) jets. Both types of processes measure minimal light-cone Fock space components of the hadron wave functions [5]. Generalization of QCD factorization theorem to hard diffractive processes will be explained [3]. We also briefly summarize experimental evidence for onset of perturbative QCD regime in exclusive vector meson production at HERA, and in pion diffraction into two jets from FNAL will be presented. [1] S. J. Brodsky, L. Frankfurt, J. F. Gunion, A. H. Mueller and M. Strikman, Phys. Rev. D50 (1994) 3134. [2] L. Frankfurt, W. Koepf, M.Strikman, Phys. Rev. D54 (1996) 1996. [3] J.C.Collins,L.Frankfurt and M.Strikman,Phys.Rev. D56 (1997)2982. [4] L. Frankfurt, W. Koepf, M.Strikman, Phys.Rev. D57(1998)512. [5] L. Frankfurt, G.A. Miller, M. Strikman, Phys.Lett.B304 (1993)1.

Frankfurt, Leonid; Strikman, Mark

1998-04-01

475

Hard Real-Time: C++ Versus RTSJ  

NASA Technical Reports Server (NTRS)

In the domain of hard real-time systems, which language is better: C++ or the Real-Time Specification for Java (RTSJ)? Although ordinary Java provides a more productive programming environment than C++ due to its automatic memory management, that benefit does not apply to RTSJ when using NoHeapRealtimeThread and non-heap memory areas. As a result, RTSJ programmers must manage non-heap memory explicitly. While that's not a deterrent for veteran real-time programmers-where explicit memory management is common-the lack of certain language features in RTSJ (and Java) makes that manual memory management harder to accomplish safely than in C++. This paper illustrates the problem for practitioners in the context of moving data and managing memory in a real-time producer/consumer pattern. The relative ease of implementation and safety of the C++ programming model suggests that RTSJ has a struggle ahead in the domain of hard real-time applications, despite its other attractive features.

Dvorak, Daniel L.; Reinholtz, William K.

2004-01-01

476

Flux monitor diode radiation hardness testing  

NASA Astrophysics Data System (ADS)

A flux monitor diode is being explored as an option for measurement of the output of an X-ray tube that is used for active transmission measurements on a pipe containing UF 6 gas. The measured flux can be used to correct for any instabilities in the X-ray tube or the high voltage power supply. For this measurement, we are using a silicon junction p-n photodiode, model AXUV100GX, developed by International Radiation Detectors, Inc. (IRD, Inc.). This diode has a silicon thickness of 104 ? and a thin (3-7 nm) silicon dioxide junction passivating, protective entrance window. These diodes have been extensively tested for radiation hardness in the UV range. However, we intend to operate mainly in the 10-40 keV X-ray region. We are performing radiation hardness testing over this energy range, with the energy spectrum that would pass through the diode during normal operation. A long-term measurement was performed at a high flux, which simulated over 80 years of operation. No significant degradation was seen over this time. Fluctuations were found to be within the 0.1% operationally acceptable error range. After irradiation, an I- V characterization showed a temporary irradiation effect which decayed over time. This effect is small because we operate the diode without external bias.

Lombardi, M. L.; Favalli, A.; Goda, J. M.; Ianakiev, K. D.; Moss, C. E.

2011-10-01

477

Hard and Soft AcidBase Behavior in Aqueous Solution: Steric Effects Make Some Metal Ions Hard: A Quantitative Scale of Hardness-Softness for Acids and Bases  

Microsoft Academic Search

The idea of hard and Soft Acids and Bases (HSAB), developed by R. G. Pearson some 30 years ago, has been used as a unifying principle in several texts. In spite of this, HSAB has remained qualitative and largely intuitive. In this article, the behaviour of HSAB in aqueous solution is addressed. A quantitative scale of hardness-softness for acids and

Robert D. Hancock; Arthur E. Martell

1996-01-01

478

Studies of chemical hardness and chemical potential on isomers and hardness profiles for hydrogen bonding systems  

SciTech Connect

Density functional theory emphasis on one electron density function {rho}, rather than on the more usual wave function {Psi}. The chemical hardness and chemical potential are the two important parameters which are playing an important role in the field of reaction chemistry, since it has been conceived as a measure of the reactivity of a system. Moreover in recent days proof of the principle of maximum hardness (PMH) is the main subject for hot discussion among the theoretical chemists. In the present investigation the chemical hardness and electronic chemical potential for the isomers of different molecules have been studied and discussed by taking account of the PMH. To probe further on this subject of PMH, hardness profiles of some hydrogen bonding systems have boom studied. The Intermolecular interactions of HF-HCI, HF-HCN, CH{sub 3}OH-H{sub 2}O and H{sub 2}O dimer have been investigated for the above purpose. Finally, the chemical reactivity, so that the stability among the above said molecules have been discussed. By considering the grand canonical ensemble, the analytical results of PMH have also been derived.

Arulmozhiraja, S.; Kolandaivel, P. [Bhararthlar Univ., Colmbatore (India)

1996-12-31

479

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

480

Allocating Hard Real-Time tasks: An NP-Hard Problem Made Easy  

Microsoft Academic Search

A distributed hard real time system can be composed from a number of communicating tasks. One of the difficulties with building such systems is the problem of where to place the tasks. In general there are P T ways of allocating T tasks to P processors, and the problem of finding an optimal feasible allocation (where all tasks meet physical

Ken Tindell; Alan Burns; Andy J. Wellings

1992-01-01

481

Spreadability and Hardness of Butter. II. Some Factors Affecting Spreadability and Hardness[1] and [2  

Microsoft Academic Search

Temperature of the cream after pasteurization and that of the butter during storage and the printing procedure had the greatest influence on hardness and spreadability of butter. Storing cream at above 48 ° F. after pasteurization, and butter below 25 ° r., improved the body of butter. Editor. With the advent of competitive spreads which emphasize superior spread- ability, consumers

V. R. Huebner; L. C. Thomsen

1957-01-01

482

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

483

[Determination of copper alloy hardness, in original form and after casting as a function of casting techniques].  

PubMed

It was evaluated the Vickers hardness of five high-copper casting alloys, in their original package form and after casting, according to the casting method used. That way, ten ingots, supplied by the manufacturers of each alloy, were included in self-curing acrylic resin, polished, numerated and submitted to Vickers hardness test at load of 200 g during 30 seconds. Afterwards the numerated ingots were removed from the acrylic resin and five of those were cast in an electrical casting machine and the other five in a centrifugal casting machine with an air/gas torch. The specimens obtained were included in self-curing acrylic resin, polished and submitted to Vickers hardness test. As a result it was verified that there is a variation of hardness among the alloys tested, and the use of the electrical casting machine produced lower hardness values than those produced when used the centrifugal casting machine with an air/gas torch. Also, there is a decrease of hardness of the cast alloys when they are tested in their original form and after casting. PMID:2099551

Bombonatti, P E; de Barros, L E; Scaranelo, R M; Pellizzer, A J; Feitosa, S A

1990-01-01

484

Polynomial complexity optimal detection for oversaturated Mary complex-valued Multiple-Access systems  

Microsoft Academic Search

The optimal multiuser detection (OMD) for binary Multiple-Access (MA) system can be posed as a binary quadratic programming (BQP) which belongs to a nondeterministic polynomial-time hard (NP-hard) problem unless the systems have some special structures. While, the OMD for PAM real-valued MA system can be posed as an integer quadratic programming (IQP) which is a problem much more difficult than

Wenlong Liu; Guannan Zhao; Jie Wang; Minglu Jin; Jaemoung Kim

2011-01-01

485

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

486

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

487

New insights from sedimentation equilibrium in an experimental hard-sphere-plus-dipolar Brownian colloidal system  

E-print Network

Hard-sphere colloids are simple conceptually, yet density-matched micron-scale colloidal hard-sphere systems for real-space microscopy are difficult to obtain in the laboratory. Colloids with a dipolar interaction are complex, with angle-dependent attractions or repulsions, and there remain unanswered questions: whether the gas-liquid transition exists, and why there is a low-density networking-forming "void" phase. In this work, we vary the electric field and measure density profiles of Brownian dipolar colloids in sedimentation equilibrium. At zero field, the equation of state matches the hard-sphere equation of state. When there is an electric field parallel to gravity, the clusters of chains form from the bottom substrate, and expand the colloidal sediment; the second virial coefficient obtained from the apparent equation of state is larger than the hard-sphere value. Additional information about the spatial distribution of hydrodynamic sizes, obtained from "sedimentation-diffusion" profiles, also shows the effects of clustering. For micron-scale dipolar colloids in gravity, clustering begins at the surface: the resulting registry between dipoles can enhance repulsions, and lead to less compact structures.

Hugh D. Newman; Anand Yethiraj

2014-12-10

488

RAPID SPECTRAL CHANGES OF CYGNUS X-1 IN THE LOW/HARD STATE WITH SUZAKU  

SciTech Connect

Rapid spectral changes in the hard X-ray on a timescale down to {approx}0.1 s are studied by applying a ''shot analysis'' technique to the Suzaku observations of the black hole binary Cygnus X-1, performed on 2008 April 18 during the low/hard state. We successfully obtained the shot profiles, covering 10-200 keV with the Suzaku HXD-PIN and HXD-GSO detector. It is notable that the 100-200 keV shot profile is acquired for the first time owing to the HXD-GSO detector. The intensity changes in a time-symmetric way, though the hardness changes in a time-asymmetric way. When the shot-phase-resolved spectra are quantified with the Compton model, the Compton y-parameter and the electron temperature are found to decrease gradually through the rising phase of the shot, while the optical depth appears to increase. All the parameters return to their time-averaged values immediately within 0.1 s past the shot peak. We have not only confirmed this feature previously found in energies below {approx}60 keV, but also found that the spectral change is more prominent in energies above {approx}100 keV, implying the existence of some instant mechanism for direct entropy production. We discuss possible interpretations of the rapid spectral changes in the hard X-ray band.

Yamada, S.; Makishima, K. [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198 (Japan); Negoro, H. [Department of Physics, College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Torii, S.; Noda, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mineshige, S. [Department of Astronomy, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan)

2013-04-20

489

Manufacture, microstructure and mechanical properties of Mo-W-N nanostructured hard films  

SciTech Connect

Mo{sub 1-x}W{sub x}N{sub y} (x = 0-0.67) hard films were fabricated on wafers of silicon and high speed steel by dc magnetron sputtering technique. The effect of tungsten concentration on the phase composition, microstructure, surface morphology, hardness, adhesion, and corrosion resistance of the films was studied by X-ray diffraction, scanning electron microscopy, nano-indentation, and scratch test. It was found that if the W concentration (x) in the film is in the range of 0-0.52, the films exhibit fcc (Mo,W)N{sub y} single phase where larger W atoms substituted Mo atoms in fcc MoN{sub y}. At higher x values (x > 0.52) the films exhibit a two-phase structure consisting of fcc (Mo,W)N{sub y} and pure bcc tungsten phase. The hardness of the Mo{sub 1-x}W{sub x}N{sub y} films increases at first with increasing x, and then decreases after passing a maximum. The maximum hardness of 47 GPa is obtained at x = 0.37 corresponding to an adhesion strength of 60 N. The Mo-W-N coated high speed steel has a lower corrosion current density and higher corrosion potential than the bare high speed steel substrates.

Yang, J.F.; Yuan, Z.G. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhang, G.G. [Department of Materials Sciences and Engineering, Nanchang Hangkong University, Nanchang 330034 (China); Wang, X.P. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Fang, Q.F., E-mail: qffang@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Department of Materials Sciences and Engineering, Nanchang Hangkong University, Nanchang 330034 (China)

2009-10-15

490

Potential energy landscape and inherent dynamics of a hard-sphere fluid.  

PubMed

Hard-sphere models exhibit many of the same kinds of supercooled-liquid behavior as more realistic models of liquids, but the highly nonanalytic 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 nonzero 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. PMID:25375501

Ma, Qingqing; Stratt, Richard M

2014-10-01

491

Potential energy landscape and inherent dynamics of a hard-sphere fluid  

NASA Astrophysics Data System (ADS)

Hard-sphere models exhibit many of the same kinds of supercooled-liquid behavior as more realistic models of liquids, but the highly nonanalytic 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 nonzero 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.

Ma, Qingqing; Stratt, Richard M.

2014-10-01

492

Succinate-bonded cellulose: A regenerable and powerful sorbent for cadmium-removal from spiked high-hardness groundwater  

Microsoft Academic Search

The primary objective of this work was to evaluate a chemically modified cellulose for the sorption efficiency and selectivity to remove cadmium from spiked high-hardness groundwater. Heterogeneous esterification of cellulose with succinic anhydride in toluene under basic conditions has proceeded very efficiently to yield the succinylated cellulose (SC) with fairly high DS value, as confirmed by FTIR and solid-state MAS

Belkacem Belhalfaoui; Abdellah Aziz; El Hadj Elandaloussi; Mohand Said Ouali; Louis Charles De Ménorval

2009-01-01

493

Intelligent marketing strategies for the Hard Rock Hotel and Casino, Las Vegas; market segmentation and customer analysis  

Microsoft Academic Search

The Hard Rock Hotel & Casino (HRHC) in Las Vegas, NV hopes to implement customer relationship management (CRM) strategies to increase overall customer value. This paper discusses our process of analyzing historical customer data and creating incentives tests in order to create accurate and useful customer segments. These customer segments can be used to target customers based on their interests,

Leah M. Churinske; Taylor Lee; Nivaan Linhares; Selenge Turbat; Francesca Wolf; W. T. Scherer

2010-01-01

494

Multifactorial comparison of disk displacement with and without reduction to normals according to temporomandibular joint hard tissue anatomic relationships  

Microsoft Academic Search

Statement of Problem. There is disagreement about the predictive value of temporomandibular joint tomographic anatomy in the diagnosis of internal derangements. Purpose. This study aimed to identify multifactorial temporomandibular hard tissue relationships that differentiate disk displacement with reduction and disk displacement without reduction from normals. Material and Methods. Temporomandibular joint tomograms from females diagnosed with unilateral disk displacement with (n=84)

Andrew G. Pullinger; Donald A. Seligman; Mike T. John; Stephen Harkins

2002-01-01

495

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

496

Relative value health insurance.  

PubMed

Increases in health costs continue to outpace general inflation, and implementation of the Patient Protection and Affordable Care Act will exacerbate the problem by adding more Americans to the ranks of the insured. The most commonly proposed solutions--bureaucratic controls, greater patient cost sharing, and changes to physician incentives--all have substantial weaknesses. This article proposes a new paradigm for rationalizing health care expenditures called "relative value health insurance," a product that would enable consumers to purchase health insurance that covers cost-effective treatments but excludes cost-ineffective treatments. A combination of legal and informational impediments prevents private insurers from marketing this type of product today, but creative use of comparative effectiveness research, funded as a part of health care reform, could make relative value health insurance possible. Data deficits, adverse selection risks, and heterogeneous values among consumers create obstacles to shifting the health insurance system to this paradigm, but they could be overcome. PMID:24523448

Korobkin, Russell

2014-04-01

497

Pseudo hard-sphere potential for use in continuous molecular-dynamics simulation of spherical and chain molecules  

NASA Astrophysics Data System (ADS)

We present a continuous pseudo-hard-sphere potential based on a cut-and-shifted Mie (generalized Lennard-Jones) potential with exponents (50, 49). Using this potential one can mimic the volumetric, structural, and dynamic properties of the discontinuous hard-sphere potential over the whole fluid range. The continuous pseudo potential has the advantage that it may be incorporated directly into off-the-shelf molecular-dynamics code, allowing the user to capitalise on existing hardware and software advances. Simulation results for the compressibility factor of the fluid and solid phases of our pseudo hard spheres are presented and compared both to the Carnahan-Starling equation of state of the fluid and published data, the differences being indistinguishable within simulation uncertainty. The specific form of the potential is employed to simulate flexible chains formed from these pseudo hard spheres at contact (pearl-necklace model) for mc = 4, 5, 7, 8, 16, 20, 100, 201, and 500 monomer segments. The compressibility factor of the chains per unit of monomer, mc, approaches a limiting value at reasonably small values, mc < 50, as predicted by Wertheim's first order thermodynamic perturbation theory. Simulation results are also presented for highly asymmetric mixtures of pseudo hard spheres, with diameter ratios of 3:1, 5:1, 20:1 over the whole composition range.

Jover, J.; Haslam, A. J.; Galindo, A.; Jackson, G.; Müller, E. A.

2012-10-01

498

The use of the durometer to measure rock hardness in geomorphology. Advantages and limitations.  

NASA Astrophysics Data System (ADS)

The durometer is a hardness tester developed to measure hardness of metallic materials that has been recently introduced to measure rock hardness in weathering studies. Aoki & Matsukura (2007) highlight some advantages of the durometer compared with the Schmidt Rock Test Hammer: the smaller plunge allows measurements in small surfaces such as taffoni or rock carvings, the wider measurement range and the lower impact energy. This last makes it a non destructive method that can be used on relatively soft rocks. In this work the durometer Equotip (©) has been tested in different environments in the field and in the laboratory to explore its applicability and limitations. We applied the device on small rock samples of granite and limestone and a T-test showed that smaller sample size gave smaller hardness values (p < 0.01). Testing the effects of water content, there were no statistically significant differences between water saturated and dry samples. The influence of rock surface roughness was evaluated applying the durometer in ancient rock carvings in medium to coarse grain granites. We compared the values obtained inside and outside the grooves of the carvings using two different support rings, one flat and one concave. The flat ring was not able to reach the bottom of the groove, meanwhile the concave ring adjusts fairly well given its semi spherical section. A t-test confirmed the difference (p < 0.01) between lower rebound values obtained in the grooves using the flat ring and the higher and less scattered values obtained when the concave ring is used. As a very sensitive device, there are some problems in the use related with rock roughness and rock grain size. In weathered medium to coarse grained rocks, with very irregular surfaces, is not easy to get a good contact between the plunge and the rock surface. A poor contact caused by surface roughness causes the scattering and lowering of rebound values. On the contrary, in homogeneous fine grained rocks and in uniform rock surfaces the device gave very good results. The data obtained in glacial, nival and rock coastal environments showed the potential of the device in the identification of changes in rock hardness. We were able to asses the changes in the weathering degree of glacial striations and marked differences in the rock surfaces subjected or not to abrasion. A. Feal-Pérez is supported by the grant AP2006-03854 (Spanish Ministry of Education)

Feal-Pérez, Alejandra; Blanco-Chao, Ramón; Valcarcel-Díaz, Marcos; Combes, Martín. A.

2010-05-01

499

Value of space defenses  

SciTech Connect

This report discusses the economic value of defenses against Near-Earth Object (NEO) impacts is bounded by calculating expected losses in their absence, which illustrates the contributions from NEOs of different sizes and the sensitivity of total expected losses to impact frequencies. For typical size distributions and damage of only a few decades duration, losses are most sensitive to small NEOs, and lead to defenses worth a few $M/yr. When the persistence of damage with NEO size is taken into account, that shifts the loss to the largest NEOs and greatly increases expected loss and values.

Canavan, G.H.

1992-10-29

500

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