Science.gov

Sample records for knoop hardness values

  1. Knoop Hardness - Apparent Yield Stress Relationship in Ceramics

    SciTech Connect

    Swab, Jeffrey J; LaSalvia, Jerry; Wereszczak, Andrew A; Strong, Kevin T; Danna, Dominic; Ragan, Meredith E; Ritt, Patrick J

    2012-01-01

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

  2. Evaluation of depth of cure and knoop hardness in a dental composite, photo-activated using different methods.

    PubMed

    Hegde, Mithra N; Hegde, Priyadarshini; Malhan, Babita

    2008-04-01

    The study aimed at evaluating the depth of cure and knoop hardness of a microfine-hybrid composite resin that was photo-activated using different methods. A bipartite brass mold was filled with composite resin and photo-activation was performed using four methods: (1) Intermittent method using quartz tungsten halogen (QTH) light curing unit (LCU) (2) Continuous method (QTH) (3) Exponential method (QTH) (4) Continuous method using light-emitting diode (LED). Depth of cure was measured at the unexposed bottom surface of the specimen using microtester as a penetrometer. The surfaces exposed to light were subjected to knoop hardness testing, using a digital microhardness tester. Knoop hardness measurements were obtained at the top surface and at depths of 1, 2, 3, 4 and 5 mm. The data was analyzed using anova and Tukey's test (5%). Results showed that the depth of cure was higher with the intermittent method (QTH), followed by the continuous method (QTH), the exponential method and the continuous method (LED). At the top surface and up to 1 mm, continuous method (LED) demonstrated the highest knoop hardness number (KHN). At 2 mm and up to 5 mm, intermittent method (QTH) presented the highest KHN and continuous method (LED) showed the lowest KHN. At all depths, continuous method (QTH) showed higher KHN, as compared to the exponential method (QTH), except at 2 mm where both showed no significant difference. PMID:20142889

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

    SciTech Connect

    Nagakubo, A.; Ogi, H. Hirao, M.; Sumiya, H.

    2014-08-25

    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.

  4. Hardness and damage associated with pointed indentations in armor ceramics

    NASA Astrophysics Data System (ADS)

    Swab, Jeffrey J.

    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.

  5. Determination of the Mechanical Properties of Plasma-Sprayed Hydroxyapatite Coatings Using the Knoop Indentation Technique

    NASA Astrophysics Data System (ADS)

    Hasan, Md. Fahad; Wang, James; Berndt, Christopher

    2015-06-01

    The microhardness and elastic modulus of plasma-sprayed hydroxyapatite coatings were evaluated using Knoop indentation on the cross section and on the top surface. The effects of indentation angle, testing direction, measurement location and applied load on the microhardness and elastic modulus were investigated. The variability and distribution of the microhardness and elastic modulus data were statistically analysed using the Weibull modulus distribution. The results indicate that the dependence of microhardness and elastic modulus on the indentation angle exhibits a parabolic shape. Dependence of the microhardness values on the indentation angle follows Pythagoras's theorem. The microhardness, Weibull modulus of microhardness and Weibull modulus of elastic modulus reach their maximum at the central position (175 µm) on the cross section of the coatings. The Weibull modulus of microhardness revealed similar values throughout the thickness, and the Weibull modulus of elastic modulus shows higher values on the top surface compared to the cross section.

  6. Knoop microhardness and FT-Raman evaluation of composite resins: influence of opacity and photoactivation source.

    PubMed

    Albino, Luis Gustavo Barrotte; Rodrigues, José Augusto; Kawano, Yoshio; Cassoni, Alessandra

    2011-01-01

    The aim of this study was to evaluate the degree of conversion by Knoop microhardness (KHN) and FT-Raman spectroscopy (FTIR) of one nanofilled (Filtek Supreme-3M-ESPE [FS]) and one microhybrid composite (Charisma-Heraeus-Kulzer [CH]), each with different opacities, namely enamel, dentin, and translucent, which were photo-activated by a quartz-tungsten-halogen lamp (QTH) and a light-emitting diode (LED). Resin was bulk inserted into a disc-shaped mold that was 2.0 mm thick and 4 mm in diameter, obtaining 10 samples per group. KHN and FTIR values were analyzed by two-way ANOVA and Tukey's tests (? = 0.05). Nanofilled resin activated by a LED presented higher microhardness values than samples activated by a QTH for dentin opacity (p < 0.05). The microhybrid resin showed no differences in KHN or FTIR values with different activation sources or opacity. The nanofilled dentin and enamel resins showed lower FTIR values than the translucent resin. The KHN values of the translucent resins were not influenced by the light source. PMID:21670859

  7. Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins.

    PubMed

    Osternack, Fernando Henrique Ruppel; Caldas, Danilo Biazzetto de Menezes; Rached, Rodrigo Nunes; Vieira, Sérgio; Platt, Jeffrey A; Almeida, Janaina Bertoncelo de

    2009-01-01

    This in vitro study evaluated the Knoop hardness of the composite resins Charisma (C) and Durafill VS (D) polymerized in 3 different conditions: at room temperature (A) (23 +/- 1 degrees C); refrigerated at 4 +/- 1 degrees C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 +/- 1 degrees C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (alpha=0.05). On the top surface, C(AI) was statistically similar to C(15I) and D(AI) to D(15I) (p>0.05). On the bottom surface, C(AI) presented higher hardness values when compared to COI and C(15I) (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C(7d) and D(7d) except for C(07d), which was not different from C(OI) at either surface (p>0.05). D(07d) showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups. PMID:19466230

  8. Molecular dynamics and theory for the contact values of the radial distribution functions of hard-disk uid mixtures

    E-print Network

    Luding, Stefan

    Molecular dynamics and theory for the contact values of the radial distribution functions of hard of the radial distribution functions of binary additive mixtures of hard disks. The simulation data are compared especially in the high-density domain. I. INTRODUCTION Model systems of hard disks and hard spheres are use

  9. Evaluation of the Various Drying Methods on Surface Hardness of Type IV Dental Stone

    PubMed Central

    Sudhakar, A; Srivatsa, G; Shetty, Rohit; Rajeswari, C L; Manvi, Supriya

    2015-01-01

    Background: Studies regarding the effect of various methods to increase the surface hardness of Type IV dental stone are not conclusive. Therefore, this study was carried out to evaluate the effect of air drying, micro oven drying and die hardener on surface hardness of Type IV dental stone. Materials and Methods: A standard metal die was fabricated; polyvinyl siloxane impression material was used to make the molds of metal die. A total of 120 specimens were obtained from two different die stones and were grouped as Group A (kalrock) and Group B (pearl stone), and were subjected to air drying for 24 h, micro oven drying and application of die hardener. These models were then subjected to surface hardness testing using the knoop hardness instrument. The obtained data were subjected to statistical analysis. Results: The hardness of Group A specimens was 64 ± 0.54 Knoop hardness number (KHN) after application of die hardener, 60.47 ± 0.41 KHN after 24 h air drying, 58.2 ± 0.88 after microwave oven drying and 24.6 ± 0.4 after 1 h air drying. The hardness of Group B specimens was 45.59 ± 0.63 KHN after application of die hardener, 40.2 ± 0.63 KHN after 24 h air drying, 38.28 ± 0.55 KHN after microwave oven drying and 19.91 ± 0.64 KHN after 1 h air drying. Conclusion: Group A showed better results than Group B at all times. Application of the die hardener showed highest hardness values followed in the order by 24 h air drying, microwave oven drying and 1 h air drying in both groups. The study showed that air drying the dies for 24 h followed by application of a single layer of the die hardener produced the best surface hardness and is recommended to be followed in practice. PMID:26124610

  10. 443R. Bock and V. Knoop (eds.), Genomics of Chloroplasts and Mitochondria, Advances in Photosynthesis and Respiration 35, pp. 443458,

    E-print Network

    Hamel, Patrice

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

  11. Relative hardness of composite buildups polymerized with two different LED lights.

    PubMed

    El-Shamy, Hassan; El-Mowafy, Omar

    2009-01-01

    The relative hardness (RH) of five composite materials was determined through polymerization via LED lights. Disk specimens were prepared by using composites composed of Artiste, an experimental glass fiber composite, Filtek Supreme, Z100, and LuxaCore. Specimens were polymerized for 10 and 20 seconds from the top surface only with two lights, Smartlite-IQ2 and DEMI LED, with light maintained 8 mm from the surface through a coronal section of the molar tooth. Knoop hardness numbers were determined for the top and bottom surfaces both immediately and 24 hours later. Ten RH values per group were calculated and data were statistically analyzed. Generally, RH increased with increasing polymerization time. The DEMI LED light resulted in RH values that were significantly higher than those obtained with Smartlite IQ2. Z100 had RH values of > 80% under most testing conditions and had the highest hardness values of all composites tested. Therefore, it is considered to be the most appropriate for core buildups. PMID:20095197

  12. [Effect of the methods of photoactivation and insertion on the hardness of composite resins].

    PubMed

    Consani, Simonides; Pereira, Samira Buselli; Sinhoreti, Mario Alexandre Coelho; Correr Sobrinho, Lourenço

    2002-01-01

    The purpose of this study was to assess the effect of methods of photoactivation and insertion on the Knoop hardness of the Z100 and Alert composite resins. The specimens were confected in cavities measuring 4 x 4 mm. The insertion of material was carried out by means of two methods: single-portion technique and insertion of two 2-mm-thick layers. When inserted in a single portion, the resin was compressed with a static load of 1 kgf on a glass slab recovered with a polyester strip, in order to remove the excess of material. After the removal of the glass slab and polyester strip, the materials were photoactivated by means of continuous light emitted by a XL 3000 unit with a light intensity of 520 mW/cm2 for 40 seconds; double pulse, with light emission of 150 mW/cm2 for 10 seconds, plus 30 seconds with light intensity of 520 mW/cm2 emitted by a XL 3000 unit; and pulsatile light of 520 mW/cm emitted by the Optilux 400 unit, turned on for 2 seconds and off for 2 seconds, during 60 seconds. The two layers of the material submitted to double insertion were photoactivated in the same conditions as the bulk-inserted material, and the excess of material was also removed from the second layer. After storage in a stove at 37 C and 100% relative humidity for 24 hours, the specimens were embedded in polyester resin, trimmed and polished with sandpaper and diamond slurry. Knoop hardness was assessed in 4 depths with a HMV Shimadzu penetrometer under the load of 50 g during 30 seconds. The data submitted to ANOVA and Tukey's test revealed that Z100 presented greater hardness values; double insertion was better than single insertion; the hardness at the surface was smaller than that at the bottom of the specimen, regardless of other factors. For Z100, all activation methods produced smaller hardness values when double insertion was carried out. Meanwhile, for Alert, continuous light promoted statistical similarity between the insertion techniques. For Z100, there was statistical similarity between the activation methods only when the double-insertion technique was employed. There was statistical similarity between the double-pulse and pulsatile-light techniques for Alert, when the single-portion insertion technique was carried out. PMID:12612776

  13. Hardness, polymerization depth, and internal adaptation of Class II silorane composite restorations as a function of polymerization protocol

    PubMed Central

    Bechtold, Janaina; dos Santos, Priscila Jaques; Anido-Anido, Andrea; Di Hipólito, Vinícius; Alonso, Roberta Caroline Bruschi; D’Alpino, Paulo Henrique Perlatti

    2012-01-01

    Objectives: To evaluate the influence of various photoactivation techniques on the internal gap, Knoop-hardness, and polymerization depth of silorane- and methacrylate-based composites in Class II restorations. Methods: Preparations were made in third molars (n = 10), according to composites (Filtek P60: methacrylate; Filtek P90: silorane) and photoactivation techniques (OC: occlusal photoactivation (control); OBL: occlusal+buccal+lingual photoactivation; and BLO: buccal+lingual+occlusal photoactivation (transdental)). Composites were inserted in two increments, both individually photoactivated for 20s. After 24h, specimens were sectioned and the ratio of internal gaps to interface length (%) recorded. Hardness was tested across the transversal section of restorations (1–4 mm below the surface). Results: Silorane restorations showed significantly lower gaps compared with methacrylate, regardless of polymerization technique (P<.05). Supplementary energy dose in OBL and BLO protocols caused significant increase in gaps in silorane restorations (P<.05). For methacrylate restorations, OBL activation caused significantly higher gap formation (P<.05). Significantly lower hardness values were seen for silorane than for methacrylate composites (P<.05), regardless of depth and photoactivation. Significantly higher hardness values were seen in BLO activation for methacrylate restorations compared with control (P<.05); for silorane, no differences were observed. Significantly higher hardness values were observed at 1 and 3 mm compared to 2 and 4 mm for both composites. Conclusions: Internal gaps and hardness are affected by composite type and photoactivation. Despite the reduced values, hardness of silorane is not influenced by photoactivation or by depth. Internal gaps are dependent on the energy dose for both composites, with silorane showing lower internal gaps. PMID:22509115

  14. Chemical compositions and nutritional value of Asian hard clam (Meretrix lusoria) from the coast of Andaman Sea.

    PubMed

    Karnjanapratum, Supatra; Benjakul, Soottawat; Kishimura, Hideki; Tsai, Yung-Hsiang

    2013-12-15

    Chemical compositions and nutritive value of the edible portions including foot, mantle and viscera of Asian hard clam (Meretrix lusoria) harvested from the coast of Andaman Sea were determined. Proximate compositions varied with portions tested. Edible portions had moisture (76.23-84.22%) and protein (9.09-12.75%) as the major components. Carbohydrate (0.32-7.89%), fat (1.58-6.58%) and ash (1.23-2.58%) were also found at various levels, dependent upon portions. Myofibrillar proteins were observed as the major fraction in foot (40.54%) and mantle (31.65%), whilst non-protein nitrogen constituents were dominant in the viscera (36.85%). All portions contained a large amount of essential amino acids (167.66-187.63 mg/g sample), in which leucine (30.91-36.96 mg/g sample) and lysine (35.24-36.03 mg/g sample) were predominant. They were rich in polyunsaturated fatty acids (46.84-49.18% of total fatty acid) with high level of DHA (13.33-16.47 % of total fatty acids) and EPA (4.75-7.11% of total fatty acids). Cholesterol of 0.07-0.21% wet weight was detected. All portions were also rich in macro- (Na, K, Ca and Mg) and micro- (Fe, Zn, Cu and Cr) minerals. Therefore, Asian hard clam is an excellent source of several nutrients, which could be beneficial for the health of the consumers. PMID:23993597

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

    PubMed Central

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

    2015-01-01

    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. PMID:25829693

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

    SciTech Connect

    Shankar, T.J.; Sokhansanj, Shahabaddine

    2010-02-01

    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 %.

  17. Microindentation hardness evaluation of iridium alloy clad vent set cups

    SciTech Connect

    Ulrich, G.B.; DeRoos, L.F.; Stinnette, S.E.

    1992-05-15

    An iridium alloy, DOP-26, is used as cladding for {sup 238}PuO{sup 2} fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration's Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

  18. Microindentation hardness evaluation of iridium alloy clad vent set cups

    SciTech Connect

    Ulrich, G.B.; DeRoos, L.F.; Stinnette, S.E.

    1992-05-15

    An iridium alloy, DOP-26, is used as cladding for {sup 238}PuO{sup 2} fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration`s Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

  19. Microindentation hardness evaluation of iridium alloy clad vent set cups

    NASA Astrophysics Data System (ADS)

    Ulrich, George B.; DeRoos, Larry F.; Stinnette, Samuel E.

    1993-01-01

    An iridium alloy, DOP-26, is used as cladding for 238PuO2 fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration's Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

  20. SUPER HARD SURFACED POLYMERS

    SciTech Connect

    Mansur, Louis K; Bhattacharya, R; Blau, Peter Julian; Clemons, Art; Eberle, Cliff; Evans, H B; Janke, Christopher James; Jolly, Brian C; Lee, E H; Leonard, Keith J; Trejo, Rosa M; Rivard, John D

    2010-01-01

    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.

  1. BOOKSHELF Hard Disk Drive

    E-print Network

    Benmei, Chen

    » BOOKSHELF Hard Disk Drive Servo Systems, 2nd edition by B.M. CHEN, T.H. LEE, K. PENG, and V- widths ever higher as higher frequency disturbances become relevant. THE BOOK Hard Disk Drive Servo I of Hard Disk Drive Servo Systems briefly discusses the history of hard drive control and the disk

  2. Rockwell Hardness Measurement of

    E-print Network

    Colton, Jonathan S.

    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

  3. Wear of hard materials by hard particles

    SciTech Connect

    Hawk, Jeffrey A.

    2003-10-01

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

  4. On the indentation recovery and fleeting hardness of polymers

    E-print Network

    Van Vliet, Krystyn J.

    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

  5. On the Hardness of Decision and Optimisation Problems

    E-print Network

    Thiébaux, Sylvie

    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

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

    ERIC Educational Resources Information Center

    Mendick, Heather; Allen, Kim; Harvey, Laura

    2015-01-01

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

  7. The Dubious Value of Value Neutrality

    ERIC Educational Resources Information Center

    Balch, Stephen H.

    2006-01-01

    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…

  8. Simulating Hard Rigid Bodies

    E-print Network

    De Michele, Cristiano

    2009-01-01

    Several physical systems in condensed matter have been modeled approximating their constituent particles as hard objects. In fact, the hard spheres model has been one of the cornerstones of the computational and theoretical description in condensed matter. The next level of description is to consider particles as rigid objects of generic shape enriching enormously the possible phenomenology. This kind of modeling will be interesting in all the situations in which steric effect plays a relevant role. These include biology, soft matter, granular material and molecular systems. Nevertheless, except for the case of hard spheres systems, there are no general recipes for event-driven Molecular Dynamics simulations of hard rigid bodies. Two similar algorithms for calculating the distance between two convex hard rigid bodies and the contact time of two colliding hard rigid bodies solving non-linear set of equations will be described. Building on these two methods, an event-driven molecular dynamics algorithm for simu...

  9. Dynamic indentation hardness of materials

    NASA Astrophysics Data System (ADS)

    Koeppel, Brian James

    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.

  10. Effects of preheating and precooling on the hardness and shrinkage of a composite resin cured with QTH and LED.

    PubMed

    Osternack, F H; Caldas, D B M; Almeida, J B; Souza, E M; Mazur, R F

    2013-01-01

    The aim of this study was to evaluate in vitro the hardness and shrinkage of a pre-cooled or preheated hybrid composite resin cured by a quartz-tungsten-halogen light (QTH) and light-emitting diode (LED) curing units. The temperature on the tip of the devices was also investigated. Specimens of Charisma resin composite were produced with a metal mold kept under 37°C. The syringes were submitted to 4°C, 23°C, and 60°C (n=20) before light-curing, which was carried out with the Optilux 501 VCL and Elipar FreeLight 2 units for 20 seconds. The specimens were kept under 37°C in a high humidity condition and darkness for 48 hours. The Knoop hardness test was carried out with a 50 gram-force (gf) load for 10 seconds, and the measurement of the shrinkage gap was carried out using an optical microscope. The data were subjected to analysis of variance and the Games-Howell test (?=0.05). The mean hardness of the groups were similar, irrespective of the temperatures (p>0.05). For 4°C and 60°C, the top surface light-cured by LED presented significantly reduced shrinkage when compared with the bottom and to both surfaces cured by QTH (p<0.05). It was concluded that the hardness was not affected by pre-cooling or preheating. However, polymerization shrinkage was slightly affected by different pre-polymerization temperatures. The QTH-curing generated greater shrinkage than LED-curing only when the composite was preheated. Different temperatures did not affect the composite hardness and shrinkage when cured by a LED curing unit. PMID:23088189

  11. Session: Hard Rock Penetration

    SciTech Connect

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

    1992-01-01

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

  12. Hardness Tester for Polyur

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  13. The hard metal diseases

    SciTech Connect

    Cugell, D.W. )

    1992-06-01

    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.

  14. Novel hard compositions and methods of preparation

    DOEpatents

    Sheinberg, H.

    1981-02-03

    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.

  15. Hard superconducting nitrides

    PubMed Central

    Chen, Xiao-Jia; Struzhkin, Viktor V.; Wu, Zhigang; Somayazulu, Maddury; Qian, Jiang; Kung, Simon; Christensen, Axel Nørlund; Zhao, Yusheng; Cohen, Ronald E.; Mao, Ho-kwang; Hemley, Russell J.

    2005-01-01

    Detailed study of the equation of state, elasticity, and hardness of selected superconducting transition-metal nitrides reveals interesting correlations among their physical properties. Both the bulk modulus and Vickers hardness are found to decrease with increasing zero-pressure volume in NbN, HfN, and ZrN. The computed elastic constants from first principles satisfy c11 > c12 > c44 for NbN, but c11 > c44 > c12 for HfN and ZrN, which are in good agreement with the neutron scattering data. The cubic ?-NbN superconducting phase possesses a bulk modulus of 348 GPa, comparable to that of cubic boron nitride, and a Vickers hardness of 20 GPa, which is close to sapphire. Theoretical calculations for NbN show that all elastic moduli increase monotonically with increasing pressure. These results suggest technological applications of such materials in extreme environments. PMID:15728352

  16. Hard superconducting nitrides.

    PubMed

    Chen, Xiao-Jia; Struzhkin, Viktor V; Wu, Zhigang; Somayazulu, Maddury; Qian, Jiang; Kung, Simon; Christensen, Axel Nørlund; Zhao, Yusheng; Cohen, Ronald E; Mao, Ho-kwang; Hemley, Russell J

    2005-03-01

    Detailed study of the equation of state, elasticity, and hardness of selected superconducting transition-metal nitrides reveals interesting correlations among their physical properties. Both the bulk modulus and Vickers hardness are found to decrease with increasing zero-pressure volume in NbN, HfN, and ZrN. The computed elastic constants from first principles satisfy c11 > c12 > c44 for NbN, but c11 > c44 > c12 for HfN and ZrN, which are in good agreement with the neutron scattering data. The cubic delta-NbN superconducting phase possesses a bulk modulus of 348 GPa, comparable to that of cubic boron nitride, and a Vickers hardness of 20 GPa, which is close to sapphire. Theoretical calculations for NbN show that all elastic moduli increase monotonically with increasing pressure. These results suggest technological applications of such materials in extreme environments. PMID:15728352

  17. What Value "Value Added"?

    ERIC Educational Resources Information Center

    Richards, Andrew

    2015-01-01

    Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…

  18. Running in Hard Times

    ERIC Educational Resources Information Center

    Berry, John N., III

    2009-01-01

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

  19. Work Hard. Be Nice

    ERIC Educational Resources Information Center

    Mathews, Jay

    2009-01-01

    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,…

  20. CSI: Hard Drive

    ERIC Educational Resources Information Center

    Sturgeon, Julie

    2008-01-01

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

  1. Soft Skills, Hard Science

    E-print Network

    Wu, Mingshen

    , and Persons with Disabilities) 6 6 #12;how to help? What factors cause students with disabilities to be less with disabilities, 680 employers who have hired in STEM areas Students rated themselves on various skills, EmployersSoft Skills, Hard Science: A Program to Improve Job Placement of STEM Graduates with Disabilities

  2. Unemployment: Hard-Core or Hard-Shell?

    ERIC Educational Resources Information Center

    Lauer, Robert H.

    1972-01-01

    The term hard-core'' makes the unemployed culpable; the term hard shell'' shifts the burden to the employer, and the evidence from the suburban plant indicates that a substantial part of the problem must lie there. (DM)

  3. Hard Copy Market Overview

    NASA Astrophysics Data System (ADS)

    Testan, Peter R.

    1987-04-01

    A number of Color Hard Copy (CHC) market drivers are currently indicating strong growth in the use of CHC technologies for the business graphics marketplace. These market drivers relate to product, software, color monitors and color copiers. The use of color in business graphics allows more information to be relayed than is normally the case in a monochrome format. The communicative powers of full-color computer generated output in the business graphics application area will continue to induce end users to desire and require color in their future applications. A number of color hard copy technologies will be utilized in the presentation graphics arena. Thermal transfer, ink jet, photographic and electrophotographic technologies are all expected to be utilized in the business graphics presentation application area in the future. Since the end of 1984, the availability of color application software packages has grown significantly. Sales revenue generated by business graphics software is expected to grow at a compound annual growth rate of just over 40 percent to 1990. Increased availability of packages to allow the integration of text and graphics is expected. Currently, the latest versions of page description languages such as Postscript, Interpress and DDL all support color output. The use of color monitors will also drive the demand for color hard copy in the business graphics market place. The availability of higher resolution screens is allowing color monitors to be easily used for both text and graphics applications in the office environment. During 1987, the sales of color monitors are expected to surpass the sales of monochrome monitors. Another major color hard copy market driver will be the color copier. In order to take advantage of the communications power of computer generated color output, multiple copies are required for distribution. Product introductions of a new generation of color copiers is now underway with additional introductions expected during 1987. The color hard copy market continues to be in a state of constant change, typical of any immature market. However, much of the change is positive. During 1985, the color hard copy market generated 1.2 billion. By 1990, total market revenue is expected to exceed 5.5 billion. The business graphics CHC application area is expected to grow at a compound annual growth rate greater than 40 percent to 1990.

  4. Novel hard compositions and methods of preparation

    DOEpatents

    Sheinberg, Haskell (Los Alamos, NM)

    1983-08-23

    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.

  5. Novel hard compositions and methods of preparation

    DOEpatents

    Sheinberg, H.

    1983-08-23

    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.

  6. Materials science Nanotubes get hard

    E-print Network

    Downs, Robert T.

    Materials science Nanotubes get hard under pressure Proc. Natl Acad. Sci. USA doi:10.1073/pnas something so hard that it cracked the diamond teeth of the apparatus. But they hadn't simply turned-pressure phase of carbon, with a density, hardness and bulk modulus (the inverse of compressibility) at least

  7. Hard-pan soils - Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hard pans, hard layers, or compacted horizons, either surface or subsurface, are universal problems that limit crop production. Hard layers can be caused by traffic or soil genetic properties that result in horizons with high density or cemented soil particles; these horizons have elevated penetrati...

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

    E-print Network

    Florida, University of

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

  9. Hard hexagon partition function for complex fugacity

    E-print Network

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

    2013-09-21

    We study the analyticity of the partition function of the hard hexagon model in the complex fugacity plane by computing zeros and transfer matrix eigenvalues for large finite size systems. We find that the partition function per site computed by Baxter in the thermodynamic limit for positive real values of the fugacity is not sufficient to describe the analyticity in the full complex fugacity plane. We also obtain a new algebraic equation for the low density partition function per site.

  10. Hard metal composition

    DOEpatents

    Sheinberg, Haskell (Los Alamos, NM)

    1986-01-01

    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.

  11. Hard metal composition

    DOEpatents

    Sheinberg, H.

    1983-07-26

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

  12. Hard physics in PHENIX

    E-print Network

    D. Peressounko; for the PHENIX collaboration

    2005-12-08

    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.

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

    E-print Network

    A. H. Mueller

    2008-05-20

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

  14. Exciting Hard Spheres

    E-print Network

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

    2008-05-25

    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.

  15. Evaluation of mechanical properties of some glycine complexes

    SciTech Connect

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

    2014-04-24

    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.

  16. Measuring the Hardness of Minerals

    ERIC Educational Resources Information Center

    Bushby, Jessica

    2005-01-01

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

  17. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-01-01

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

  18. Overview - Hard Rock Penetration

    SciTech Connect

    Dunn, James C.

    1992-03-24

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

  19. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-08-01

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

  20. Beta Backscatter Measures the Hardness of Rubber

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  1. Hardness Amplification Proofs Require Majority Ronen Shaltiel

    E-print Network

    Viola, Emanuele

    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

  2. Hard hadron spectroscopy

    E-print Network

    Craig McNeile

    2009-07-01

    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.

  3. Hardness variability in commercial technologies

    SciTech Connect

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

    1994-12-01

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

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

    SciTech Connect

    Manjura Hoque, S.; Srivastava, C.; Kumar, V.; Venkatesh, N.; Das, H.N.; Saha, D.K.; Chattopadhyay, K.

    2013-08-01

    Graphical abstract: - Highlights: • Exchange-spring behaviour of soft and hard ferrites was studied. • XRD patterns indicated soft and hard ferrites as fcc and hcp structure. • Hysteresis loops indicate wide difference in coercivity of soft and hard phases. • Nanocomposites produced convex hysteresis loop characteristic of single-phase. - Abstract: The paper reports exchange-spring soft and hard ferrite nanocomposites synthesized by chemical co-precipitation with or without the application of ultrasonic vibration. The composites contained BaFe{sub 12}O{sub 19} as the hard phase and CoFe{sub 2}O{sub 4}/MgFe{sub 2}O{sub 4} as the soft phase. X-ray diffraction patterns of the samples in the optimum calcined condition indicated the presence of soft ferrites as face-centred cubic (fcc) and hard ferrites as hexagonal close packed (hcp) structure respectively. Temperature dependence of magnetization in the range of 20–700 °C demonstrated distinct presence of soft and hard ferrites as magnetic phases which are characterized by wide difference in magnetic anisotropy and coercivity. Exchange-spring mechanism led these nanocomposite systems to exchange-coupled, which ultimately produced convex hysteresis loops characteristic of a single-phase permanent magnet. Fairly high value of coercivity and maximum energy product were observed for the samples in the optimum calcined conditions with a maximum applied field of 1600 kA/m (2 T)

  5. Hardness and fracture toughness of bulk single crystal gallium nitride

    SciTech Connect

    Drory, M.D.; Ager, J.W. III; Suski, T.; Grzegory, I.; Porowski, S.

    1996-12-01

    Basic mechanical properties of single crystal gallium nitride are measured. A Vickers (diamond) indentation method was used to determine the hardness and fracture toughness under an applied load of 2N. The average hardness was measured as 12{plus_minus}2 GPa and the average fracture toughness was measured as 0.79{plus_minus}0.10 MPa{radical}m. These values are consistent with the properties of brittle ceramic materials and about twice the values for GaAs. A methodology for examining fracture problems in GaN is discussed. {copyright} {ital 1996 American Institute of Physics.}

  6. Demixing in binary mixtures of apolar and dipolar hard spheres

    NASA Astrophysics Data System (ADS)

    Almarza, N. G.; Lomba, E.; Martín, C.; Gallardo, A.

    2008-12-01

    We study the demixing transition of mixtures of equal size hard spheres and dipolar hard spheres using computer simulation and integral equation theories. Calculations are carried out at constant pressure, and it is found that there is a strong correlation between the total density and the composition. The critical temperature and the critical total density are found to increase with pressure. The critical mole fraction of the dipolar component on the contrary decreases as pressure is augmented. These qualitative trends are reproduced by the theoretical approaches that on the other hand overestimate by far the value of the critical temperature. Interestingly, the critical parameters for the liquid-vapor equilibrium extrapolated from the mixture results in the limit of vanishing neutral hard sphere concentration agree rather well with recent estimates based on the extrapolation of charged hard dumbbell phase equilibria when dumbbell elongation shrinks to zero [G. Ganzenmüller and P. J. Camp, J. Chem. Phys. 126, 191104 (2007)].

  7. Density Profiles of a Hard Gaussian Overlap Fluid Between Hard Walls

    NASA Astrophysics Data System (ADS)

    Moradi, M.; Avazpour, A.

    The density profiles of a hard Gaussian overlap (HGO) fluid confined in between hard walls and in contact with a hard wall are studied using the density functional theory. The hyper-netted chain (HNC) approximation is used to find the coupled integral equations for the density profiles. The restricted orientation model (ROM) is used. The required homogeneous direct correlation function (DCF) is obtained by solving Ornstein-Zernike (OZ) integral equation numerically, using the Precus-Yevick (PY) approximation and the procedure mentioned by Letz and Latz [Phys. Rev. E60, 5865 (1999)]. We also obtained the DCF of hard ellipsoidal (HE) fluid by using the modified closest approach introduced by Rickayzen [Mol. Phys. 68, 903 (1989)]. For both HGO and HE, we calculate the density profiles of molecules parallel and perpendicular to the walls and we compare the results. The calculations are performed for various values of packing fractions of the fluid and various molecular elongations. For moderate elongations, k?3, the results for HGO and HE are almost the same, especially for the density profile of the molecules parallel to the walls but for k=5 there are some discrepancies between the results, in particular for the density profiles of the molecules perpendicular to the walls.

  8. A finger-like hardness tester based on the contact electromechanical impedance of a piezoelectric bimorph cantilever.

    PubMed

    Fu, Ji; Li, Faxin

    2015-10-01

    We proposed a finger-like hardness tester based on the electromechanical impedance of a piezoelectric bimorph cantilever. A Vickers indenter was fabricated to the free end of the bimorph to contact the sample. The contact force was monitored by a strain gauge and the contact area was obtained by tracking the bimorph's resonance frequency. The bimorph-sample contact system was modeled by the electromechanical equivalent circuit method. Verification experiments on standard hardness samples were conducted and the measured hardness values agreed well with those given by a conventional Vickers hardness tester. Further hardness measurement on a gear wheel showed that the proposed hardness tester is very adaptive and can be used for inner surface testing or in situ testing, where other hardness testers may not be applicable. The proposed hardness tester can be regarded as an improved ultrasonic hardness tester. PMID:26520966

  9. A finger-like hardness tester based on the contact electromechanical impedance of a piezoelectric bimorph cantilever

    NASA Astrophysics Data System (ADS)

    Fu, Ji; Li, Faxin

    2015-10-01

    We proposed a finger-like hardness tester based on the electromechanical impedance of a piezoelectric bimorph cantilever. A Vickers indenter was fabricated to the free end of the bimorph to contact the sample. The contact force was monitored by a strain gauge and the contact area was obtained by tracking the bimorph's resonance frequency. The bimorph-sample contact system was modeled by the electromechanical equivalent circuit method. Verification experiments on standard hardness samples were conducted and the measured hardness values agreed well with those given by a conventional Vickers hardness tester. Further hardness measurement on a gear wheel showed that the proposed hardness tester is very adaptive and can be used for inner surface testing or in situ testing, where other hardness testers may not be applicable. The proposed hardness tester can be regarded as an improved ultrasonic hardness tester.

  10. The hard truth

    SciTech Connect

    Hanson, K.M.; Cunningham, C.S.

    1994-12-31

    In the Bayesian methodology, the posterior probability combines uncertainty about prior knowledge, and available data about alternative models of reality. The posterior quantifies the degree of certainty one has in inferring the truth in terms of those models. We propose a method to determine the reliability of a specific feature of a Bayesian solution. Our approach is based on an analogy between the negative logarithm of the posterior and a physical potential. This analogy leads to the interpretation of gradient of this potential as a force that acts on the model. As model parameters are perturbed from their maximum a posteriori (MAP) values, the strength of the restoring force that drives them back to the MAP solution is directly related to the reliability of those parameter estimates. The correlations between the uncertainties of parameter estimates can be elucidated.

  11. Segregation of Fluidized Binary Hard-Sphere Systems Under Gravity

    NASA Astrophysics Data System (ADS)

    Kim, Soon-Chul

    We have derived an analytic expression for the contact value of the local density of binary hard-sphere systems under gravity. We have obtained the crossover conditions for the Brazil-nut type segregation of binary hard-sphere mixtures and binary hard-sphere chain mixtures from the segregation criterion, where the segregation occurs when the density (or the pressure) of the small spheres at the bottom is higher than that of the large spheres, or vice versa. For the binary hard-sphere chain mixtures, the crossover condition for the segregation depends on the number of monomers composed of hard-sphere chains as well as the mass and the diameter of each species. The fundamental-measure theories (FMTs) and local density approximation (LDA) are employed to examine the crossover condition for the segregation of the gravity-induced hard-sphere mixtures. The calculated results show that the LDA does not explain the density oscillation near the bottom, whereas the modified fundamental-measure theory (MFMT) compares with molecular dynamics simulations.

  12. Hard Homogeneous Spaces JeanMarc Couveignes

    E-print Network

    International Association for Cryptologic Research (IACR)

    Hard Homogeneous Spaces Jean­Marc Couveignes August 24, 2006 Abstract This note was written in 1997 be, I will publish an updated version later. We introduce the notion of hard homogeneous space (HHS logarithm problem have a counterpart for any hard homogeneous space. Indeed, the notion of hard homogeneous

  13. Hard Homogeneous Spaces Jean-Marc Couveignes

    E-print Network

    International Association for Cryptologic Research (IACR)

    Hard Homogeneous Spaces Jean-Marc Couveignes August 24, 2006 Abstract This note was written in 1997 be, I will publish an updated version later. We introduce the notion of hard homogeneous space (HHS logarithm problem have a counterpart for any hard homogeneous space. Indeed, the notion of hard homogeneous

  14. The Complexity of Hardness Amplification and Derandomization

    E-print Network

    Viola, Emanuele

    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

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

    NASA Astrophysics Data System (ADS)

    Mart?nez-Ratón, Y.; Cinacchi, G.; Velasco, E.; Mederos, L.

    2006-10-01

    It is known that when hard spheres are added to a pure system of hard rods the stability of the smectic phase may be greatly enhanced, and that this effect can be rationalised in terms of depletion forces. In the present paper we first study the effect of orientational order on depletion forces in this particular binary system, comparing our results with those obtained adopting the usual approximation of considering the rods parallel and their orientations frozen. We consider mixtures with rods of different aspect ratios and spheres of different diameters, and we treat them within Onsager theory. Our results indicate that depletion effects, and consequently smectic stability, decrease significantly as a result of orientational disorder in the smectic phase when compared with corresponding data based on the frozen-orientation approximation. These results are discussed in terms of the ? parameter, which has been proposed as a convenient measure of depletion strength. We present closed expressions for ?, and show that it is intimately connected with the depletion potential. We then analyse the effect of particle geometry by comparing results pertaining to systems of parallel rods of different shapes (spherocylinders, cylinders and parallelepipeds). We finally provide results based on the Zwanzig approximation of a fundamental-measure density-functional theory applied to mixtures of parallelepipeds and cubes of different sizes. In this case, we show that the ? parameter exhibits a linear asymptotic behaviour in the limit of large values of the hard-rod aspect ratio, in conformity with Onsager theory, as well as in the limit of large values of the ratio of rod breadth to cube side length, d, in contrast to Onsager approximation, which predicts ? ˜ d3. Based on both this result and the Percus-Yevick approximation for the direct correlation function for a hard-sphere binary mixture in the same limit of infinite asymmetry, we speculate that, for spherocylinders and spheres, the ? parameter should be of order unity as d tends to infinity.

  16. Hard diffraction -- 20 years later

    E-print Network

    Gunnar Ingelman

    2005-12-12

    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.

  17. Magnetic levitation for hard superconductors

    SciTech Connect

    Kordyuk, A.A.

    1998-01-01

    An approach for calculating the interaction between a hard superconductor and a permanent magnet in the field-cooled case is proposed. The exact solutions were obtained for the point magnetic dipole over a flat ideally hard superconductor. We have shown that such an approach is adaptable to a wide practical range of melt-textured high-temperature superconductors{close_quote} systems with magnetic levitation. In this case, the energy losses can be calculated from the alternating magnetic field distribution on the superconducting sample surface. {copyright} {ital 1998 American Institute of Physics.}

  18. Collision statistics in sheared inelastic hard spheres

    E-print Network

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

    2009-03-24

    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.

  19. Exclusive, hard diffraction in QCD

    NASA Astrophysics Data System (ADS)

    Freund, Andreas

    In the first chapter we give an introduction to hard diffractive scattering in QCD to introduce basic concepts and terminology, thus setting the stage for the following chapters. In the second chapter we make predictions for nondiagonal parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA, solve the nondiagonal GLAP evolution equations with a modified version of the CTEQ-package and comment on the range of applicability of the LLA in the asymmetric regime. We show that the nondiagonal gluon distribution g(x1,x2,t,?2) can be well approximated at small x by the conventional gluon density xG(x,?2). In the third chapter, we discuss the algorithms used in the LO evolution program for nondiagonal parton distributions in the DGLAP region and discuss the stability of the code. Furthermore, we demonstrate that we can reproduce the case of the LO diagonal evolution within less than 0.5% of the original code as developed by the CTEQ-collaboration. 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. Furthermore, we show that the virtuality of the produced photon does not influence the general theorem. In chapter 5, we demonstrate that perturbative QCD allows one to calculate the absolute cross section of diffractive exclusive production of photons at large Q2 at HERA, while the aligned jet model allows one to estimate the cross section for intermediate Q2~2GeV2. Furthermore, we find that the imaginary part of the amplitude for the production of real photons is larger than the imaginary part of the corresponding DIS amplitude, leading to predictions of a significant counting rate for the current generation of experiments at HERA. We also find a large azimuthal angle asymmetry in ep scattering for HERA kinematics which allows one to directly measure the real part of the DVCS amplitude and hence the nondiagonal parton distributions. In the last chapter, we propose a new methodology of gaining shape fits to nondiagonal 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 F2(x,Q2) to compute the asymmetry A for the combined DVCS and Bethe- Heitler cross section. The asymmetry A, isolates the interference term of DVCS and Bethe-Heitler in the total cross section, in other words, by isolating the real part of the DVCS amplitude through this asymmetry one has access to the nondiagonal parton distributions for the first time. Comparing the predictions for A against experiment would allow one to make a prediction of the shape, though not absolute value, of nondiagonal parton distributions. In the appendix, to illustrate an application of distributional methods as discussed in chapter 4, we will show, with the aid of simple examples, how to make simple estimates of the sizes of higher-order Feynman graphs. Our methods enable appropriate values of renormalization and factorization scales to be made. They allow the diagnosis of the source of unusually large corrections that are in need of resummation.

  20. Submicron cubic boron nitride as hard as diamond

    SciTech Connect

    Liu, Guoduan; Kou, Zili E-mail: yanxz@hpstar.ac.cn; Lei, Li; Peng, Fang; Wang, Qiming; Wang, Kaixue; Wang, Pei; Li, Liang; Li, Yong; Wang, Yonghua; Yan, Xiaozhi E-mail: yanxz@hpstar.ac.cn; Li, Wentao; Bi, Yan; Leng, Yang; He, Duanwei

    2015-03-23

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

  1. Submicron cubic boron nitride as hard as diamond

    NASA Astrophysics Data System (ADS)

    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

    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.

  2. Value Added

    ERIC Educational Resources Information Center

    Welch, Matt

    2004-01-01

    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…

  3. Valuing Conflict

    ERIC Educational Resources Information Center

    Hoerr, Thomas R.

    2004-01-01

    School leaders have a habit of minimizing disagreements among faculty and staff by capitalizing on the goals and values that everyone shares. When conflict rears its head at a meeting, it can be lessened by simply reminding colleagues of common purpose and finding issues on which all can agree. What started as an argument about curricular…

  4. Hard edge limit of the product of two strongly coupled random matrices

    E-print Network

    Gernot Akemann; Eugene Strahov

    2015-11-30

    We investigate the hard edge scaling limit of the ensemble defined by the squared singular values of the product of two coupled complex random matrices. When taking the coupling parameter to be dependent on the size of the product matrix, in a certain double scaling regime at the origin the two matrices become strongly coupled and we obtain a new hard edge limiting kernel. It interpolates between the classical Bessel-kernel describing the hard edge scaling limit of the Laguerre ensemble of a single matrix, and the Meijer G-kernel of Kuijlaars and Zhang describing the hard edge scaling limit for the product of two independent Gaussian complex matrices.

  5. FATIGUE OF BIOMATERIALS: HARD TISSUES

    PubMed Central

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

    2009-01-01

    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

  6. Playing the Numbers: Hard Choices

    ERIC Educational Resources Information Center

    Doyle, William R.

    2009-01-01

    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…

  7. Hard scattering in ?p interactions

    NASA Astrophysics Data System (ADS)

    Ahmed, T.; Andreev, V.; Andrieu, B.; Arpagaus, M.; Babayev, A.; Bärwolff, H.; Ban, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bassler, U.; Beck, G. A.; Beck, H. P.; Behrend, H.-J.; Belousov, A.; Berger, Ch.; Bergstein, H.; Bernardi, G.; Bernet, R.; Berthon, U.; Bertrand-Coremans, G.; Besancon, M.; Biddulph, P.; Binder, E.; Bizot, J. C.; Blobel, V.; Borras, K.; Bosetti, P. C.; Boudry, V.; Bourdarios, C.; Brasse, F.; Braun, U.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Bürger, J.; Büsser, F. W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A. J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A. B.; Colombo, M.; Coughlan, J. A.; Courau, A.; Coutures, C.; Cozzika, G.; Criegee, L.; Cvach, J.; Dainton, J. B.; Danilov, M.; Dann, A. W. E.; Dau, W. D.; David, M.; Deffur, E.; Delcourt, B.; DelBuono, L.; Devel, M.; DeRoeck, A.; Dingus, P.; Dollfus, C.; Dowell, J. D.; Dreis, H. B.; Drescher, A.; Duboc, J.; Düllmann, D.; Dünger, O.; Duhm, H.; Eberle, M.; Ebert, J.; Ebert, T. R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellis, N. N.; Ellison, R. J.; Elsen, E.; Erdmann, M.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Feng, Y.; Fensome, I. F.; Ference, J.; Ferrarotto, F.; Flauger, W.; Fleischer, M.; Flügge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formanek, J.; Foster, J. M.; Franke, G.; Fretwurst, E.; Fuhrmann, P.; Gabathuler, E.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gellrich, A.; Gennis, M.; Gensch, U.; Genzel, H.; Gerhards, R.; Gillespie, D.; Godfrey, L.; Goerlach, U.; Goerlich, L.; Goldberg, M.; Goodall, A. M.; Gorelov, I.; Goritchev, P.; Grab, C.; Grässler, H.; Grässler, R.; Greenshaw, T.; Greif, H.; Grindhammer, G.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Handschuh, D.; Hanlon, E. M.; Hapke, M.; Harjes, J.; Hartz, P.; Haydar, R.; Haynes, W. J.; Heatherington, J.; Hedberg, V.; Hedgecock, R.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herma, R.; Herynek, I.; Hildesheim, W.; Hill, P.; Hilton, C. D.; Hladky, J.; Hoeger, K. C.; Huet, Ph.; Hufnagel, H.; Huot, N.; Ibbotson, M.; Jabiol, M. A.; Jacholkowska, A.; Jacobson, C.; Jaffre, M.; Jönsson, L.; Johannsen, K.; Johnson, D.; Johnson, L.; Jung, H.; Kalmus, P. I. P.; Kasarian, S.; Kaschowitz, R.; Kasselmann, P.; Kathage, U.; Kaufmann, H. H.; Kenyon, I. R.; Kermiche, S.; Kiesling, C.; Klein, M.; Kleinwort, C.; Knies, G.; Köhler, T.; Kolanoski, H.; Kole, F.; Kolya, S. D.; Korbel, V.; Korn, M.; Kostka, P.; Kotelnikov, S. K.; Krasny, M. W.; Krehbiel, H.; Krücker, D.; Krüger, U.; Kubenka, J. P.; Küster, H.; Kuhlen, M.; Kurca, T.; Kurzhöfer, J.; Kuznik, B.; Lander, R.; Landon, M. P. J.; Langkau, R.; Lanius, P.; Laporte, J. F.; Lebedev, A.; Lenhardt, U.; Leuschner, A.; Leverenz, C.; Levin, D.; Levonian, S.; Ley, Ch.; Lindström, G.; Loch, P.; Lohmander, H.; Lopez, G. C.; Lüers, D.; Magnussen, N.; Malinovski, E.; Mani, S.; Marage, P.; Marks, J.; Marshall, R.; Martens, J.; Martin, R.; Martyn, H.-U.; Martyniak, J.; Masson, S.; Mavroidis, A.; Maxfield, S. J.; McMahon, S. J.; Mehta, A.; Meier, K.; Merz, T.; Meyer, C. A.; Meyer, H.; Meyer, J.; Mikocki, S.; Milone, V.; Monnier, E.; Moreau, F.; Moreels, J.; Morris, J. V.; Morton, J. M.; Müller, K.; Murin, P.; Murray, S. A.; Nagovizin, V.; Naroska, B.; Naumann, Th.; Newton, D.; Nguyen, H. K.; Niebergall, F.; Nisius, R.; Nowak, G.; Noyes, G. W.; Nyberg, M.; Oberlack, H.; Obrock, U.; Olsson, J. E.; Orenstein, S.; Ould-Saada, F.; Pascaud, C.; Patel, G. D.; Peppel, E.; Peters, S.; Phillips, H. T.; Phillips, J. P.; Pichler, Ch.; Pilgram, W.; Pitzl, D.; Prosi, R.; Raupach, F.; Rauschnabel, K.; Reimer, P.; Ribarics, P.; Riech, V.; Riedlberger, J.; Rietz, M.; Robertson, S. M.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Royon, C.; Rudowicz, M.; Ruffer, M.; Rusakov, S.; Rybicki, K.; Ryseck, E.; Sacton, J.; Sahlmann, N.; Sanchez, E.; Sankey, D. P.; Savitsky, M.; Schacht, P.; Schleper, P.; von Schlippe, W.; Schmidt, C.; Schmidt, D.; Schmitz, W.; Schröder, V.; Schulz, M.; Schwind, A.; Scobel, W.; Seehausen, U.; Sell, R.; Seman, M.; Semenov, A.; Shekelyan, V.; Sheviakov, I.; Shooshtari, H.; Siegmon, G.; Siewert, U.; Sirois, Y.; Skillicorn, I. O.; Smirnov, P.; Smith, J. R.; Smolik, L.; Soloviev, Y.; Spitzer, H.; Staroba, P.; Steenbock, M.; Steffen, P.; Steinberg, R.; Steiner, H.; Stella, B.; Stephens, K.; Strachota, J.; Straumann, U.; Struczinski, W.; Sutton, J. P.; Taylor, R. E.; Thompson, G.; Thompson, R. J.; Tichomirov, I.; Trenkel, C.; Truöl, P.; Tchernyshov, V.; Turnau, J.; Tutas, J.; Urban, L.; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; VanEsch, P.; Vartapetian, A.; Vasdik, J.; Vecko, M.; Verrecchia, P.; Vick, R.; Villet, G.; Vogel, E.; Wacker, K.; Walker, I. W.; Walther, A.; Weber, G.; Wegener, D.; Wegner, A.

    1992-12-01

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

  8. Quantum quench with hard wall boundary conditions

    NASA Astrophysics Data System (ADS)

    Goldstein, Garry; Andrei, Natan

    2015-03-01

    In this work we present analysis of a quench for the Lieb Liniger gas contained in a large box with hard wall boundary conditions. We study the time average of local correlation functions. We show that both the quench action logic and the GGE are applicable. We show that the time average of the system corresponds to an eigenstate of the Lieb Liniger Hamiltonian. We show that this eigenstate is related to an eigenstate of a Lieb Liniger Hamiltonian with periodic boundary conditions on an interval of twice the length and with twice as many particles (a doubled system). We further show that local operators with support far away from the boundaries of the hard wall Lieb Liniger gas have the same expectation values as corresponding operators for the doubled system. We present an example of a quench where the Lieb Liniger gas is initially confined in several traps and then released into a bigger container, an approximate description of the Newton cradle experiment. This research was supported by NSF Grant DMR 1006684 and Rutgers CMT fellowship.

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

    NASA Technical Reports Server (NTRS)

    Stanford, Malcolm K.

    2012-01-01

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

  10. Hard spheres out of equilibrium

    NASA Astrophysics Data System (ADS)

    Hermes, M.

    2010-05-01

    In this thesis, experiments and simulations are combined to investigate the nonequilibrium behaviour of hard spheres. In the first chapters we use Molecular Dynamics simulations to investigate the dynamic glass transition of polydisperse hard spheres. We show that this dynamic transition is accompanied by a thermodynamic signature. The higher-order derivatives of the pressure change abruptly at the dynamic glass transition. If a system is compressed beyond this dynamic transition, the pressure increases until it diverges when the system is completely jammed. The density at which the pressure diverges depends on the compression speed. We proceed with experiments on colloidal polymethylmethacrylate (PMMA) particles which closely resemble hard spheres. We investigate the effect of compression using gravity and electric field gradients on the nucleation and on the glass transition. The transition from glass to crystal is gradual and is strongly effected by gravity. We go back to computer simulations to investigate two different techniques to calculate the rate at which a hard-sphere system nucleates. We find that the two techniques yield similar results for the nucleation rate as well as the critical nucleus shape. From this we conclude that the simulation techniques are valid. A combination of simulations and experiments is used to study the nucleation of hard spheres on seed structures. We initiate the nucleation with a seed of particles kept in place by optical tweezers. We show that whereas the nucleation itself can be well described as an equilibrium process, the growth after nucleation can not. We demonstrate that defects play an important role in the growth of the crystal. Colloidal hard spheres can also be driven out of equilibrium using shear. We perform experiments on an equilibrium fluid phase below the coexistence density of the fluid. We show that we can induce order in an equilibrium fluid using oscillatory shear. We find five different phases for varying frequency and amplitude: four known phases and one new phase. The formation of all phases occurs via nucleation and growth and the melting, when the shear is stopped, starts on the edges and near the defects of the crystal phases. In the final chapter, we investigate the interactions between rough colloidal particles in the presence of polymers. We investigate whether surface roughness can be used to reduce the depletion attraction. We find that when the polymer is smaller than the surface roughness the attraction can be reduced significantly compared to smooth colloids.

  11. Estimation of Rock Cuttability from Shore Hardness and Compressive Strength Properties

    NASA Astrophysics Data System (ADS)

    Tumac, D.; Bilgin, N.; Feridunoglu, C.; Ergin, H.

    2007-10-01

    Shore hardness has been used to estimate some mechanical and physical properties of rocks for many years. This study differs from previous studies in a way that it is directly oriented to rock cuttability. Two Shore hardness values ( SH 1 and SH 2) and a coefficient of deformation value ( K) have been measured for 30 different rock samples. In the first stage of the study, optimum specific energy values for 16 different rock samples obtained from full-scale cutting tests were correlated with the Shore hardness values of the same rock samples changing SH 1 values from 9 to 66 and SH 2 values from 25 to 83, with deformation coefficient values changing from 26 to 195. In the second stage, the performance of a roadheader used in the Küçüksu (Istanbul) tunnel was recorded in detail and the instantaneous cutting rate of the machine was determined. Then, the relationship between Shore hardness values, deformation coefficient and the instantaneous cutting rate of the machine was determined for different formations encountered. It is concluded that there is a relationship between Shore hardness values, optimum specific energy and compressive strength, which may be used to estimate the rock cuttability and the instantaneous cutting rates of roadheaders within certain limits of reliability.

  12. Elasticity of Interfacial Rafts of Hard Particles with Soft Shells

    E-print Network

    Sebastian Knoche; Jan Kierfeld

    2015-05-10

    We study an elasticity model for compressed protein monolayers or particle rafts at a liquid interface. Based on the microscopic view of hard-core particles with soft shells, a bead-spring model is formulated and analyzed in terms of continuum elasticity theory. The theory can be applied, for example, to hydrophobin-coated air-water interfaces or, more generally, to liquid interfaces coated with an adsorbed monolayer of interacting hard-core particles. We derive constitutive relations for such particle rafts and describe the buckling of compressed planar liquid interfaces as well as their apparent Poisson ratio. We also use the constitutive relations to obtain shape equations for pendant or buoyant capsules attached to a capillary, and to compute deflated shapes of such capsules. A comparison with capsules obeying the usual Hookean elasticity (without hard cores) reveals that the hard cores trigger capsule wrinkling. Furthermore, it is shown that a shape analysis of deflated capsules with hard-core/soft-shell elasticity gives apparent elastic moduli which can be much higher than the original values if Hookean elasticity is assumed.

  13. Elasticity of interfacial rafts of hard particles with soft shells.

    PubMed

    Knoche, Sebastian; Kierfeld, Jan

    2015-05-19

    We study an elasticity model for compressed protein monolayers or particle rafts at a liquid interface. Based on the microscopic view of hard-core particles with soft shells, a bead-spring model is formulated and analyzed in terms of continuum elasticity theory. The theory can be applied, for example, to hydrophobin-coated air-water interfaces or, more generally, to liquid interfaces coated with an adsorbed monolayer of interacting hard-core particles. We derive constitutive relations for such particle rafts and describe the buckling of compressed planar liquid interfaces as well as their apparent Poisson ratio. We also use the constitutive relations to obtain shape equations for pendant or buoyant capsules attached to a capillary, and to compute deflated shapes of such capsules. A comparison with capsules obeying the usual Hookean elasticity (without hard cores) reveals that the hard cores trigger capsule wrinkling. Furthermore, it is shown that a shape analysis of deflated capsules with hard-core/soft-shell elasticity gives apparent elastic moduli which can be much higher than the original values if Hookean elasticity is assumed. PMID:25901364

  14. Hardness Alternation in ?,?-Alkanedicarboxylic Acids.

    PubMed

    Mishra, Manish Kumar; Ramamurty, Upadrasta; Desiraju, Gautam R

    2015-10-01

    The variation of hardness as a function of the number of carbon atoms in ?,?-alkanedicarboxylic acids, C(N)H(2N-2)O4 (4?N?9), was examined by recourse to nanoindentation on the major faces of single crystals. Hardness exhibits odd-even alternation, with the odd acids being softer and the even ones harder; the differences decrease with increasing chain length. These variations are similar to those seen for other mechanical, physical, and thermal properties of these diacids. The softness of odd acids is rationalized due to strained molecular conformations in them, which facilitate easier plastic deformation. Relationships between structural features, such as interplanar spacing, interlayer separation distance, molecular chain length, and signatures of the nanoindentation responses, namely, discrete displacement bursts, were also examined. Shear sliding of molecular layers past each other during indentation is key to the mechanism for plastic deformation in these organic crystals. PMID:25919633

  15. Ultrasonic material hardness depth measurement

    DOEpatents

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

    1997-01-01

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

  16. Ultrasonic material hardness depth measurement

    DOEpatents

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

    1997-07-08

    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.

  17. Why Are Drugs So Hard to Quit?

    MedlinePLUS Videos and Cool Tools

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

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

    PubMed Central

    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

    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

  19. The relationship between grain hardness, dough mixing parameters and bread-making quality in winter wheat.

    PubMed

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

    2012-01-01

    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

  20. Microwave assisted hard rock cutting

    DOEpatents

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

    1991-01-01

    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).

  1. Schwannoma of the hard palate

    PubMed Central

    Sahoo, Pradyumna Kumar; Mandal, Palash Kumar; Ghosh, Saradindu

    2014-01-01

    Schwannomas are benign encapsulated perineural tumors. The head and neck region is the most common site. Intraoral origin is seen in only 1% of cases, tongue being the most common site; its location in the palate is rare. We report a case of hard-palate schwannoma with bony erosion which was immunohistochemically confirmed. The tumor was excised completely intraorally. After two months of follow-up, the defect was found to be completely covered with palatal mucosa. PMID:25298716

  2. Uniformly Hard Languages \\Lambda Rod Downey y

    E-print Network

    Downey, Rod

    Uniformly Hard Languages \\Lambda Rod Downey y Department of Mathematics Victoria University P. O of ``uniformly hard languages,'' where a language is just not merely infinitely often not computable in polynomial­time but in fact the languages are hard nearly everywhere. We conjecture that all NP

  3. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  4. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  5. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  6. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  7. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  8. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  9. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  10. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hard seed. 201.21 Section 201.21 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard...

  11. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  12. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  13. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  14. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  15. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  16. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  17. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard...

  18. Warren G. Harding and the Press.

    ERIC Educational Resources Information Center

    Whitaker, W. Richard

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

  19. Using Nondeterminism to Amplify Hardness Alexander Healy

    E-print Network

    Vadhan, Salil

    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

  20. Input Locality and Hardness Amplification Andrej Bogdanov

    E-print Network

    Bogdanov, Andrej

    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

  1. Texts in Computational Complexity: Amplification of Hardness

    E-print Network

    Goldreich, Oded

    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

  2. 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

  3. PROTEIN COMPOSITION AND GRAIN HARDNESS IN SORGHUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grain hardness is an important quality trait in sorghum. Grain hardness has been linked to milling and food quality as well as resistance to insects and mold. Despite the importance of grain hardness in sorghum, its biochemical basis is still not well understood. In sorghum, the grain is composed...

  4. Hard Metric from Cayley Graphs Yuri Rabinovich

    E-print Network

    Newman, Ilan

    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

  5. 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

  6. GENETIC PROGRAMMING WITH HISTORICALLY ASSESSED HARDNESS

    E-print Network

    Spector, Lee

    Chapter 1 GENETIC PROGRAMMING WITH HISTORICALLY ASSESSED HARDNESS Jon Klein1 and Lee Spector1 1 of the genetic programming algorithm, called Histor- ically Assessed Hardness (HAH), in which the fitness rewards: historically assessed hardness, implicit fitness sharing, Push, PushGP This is a preprint copy of: Klein, J

  7. Empirical Hardness Models for Combinatorial Auctions

    E-print Network

    Shoham, Yoav

    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

  8. Hardness Amplification within NP against Deterministic Algorithms

    E-print Network

    Guruswami, Venkatesan

    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

  9. Using Nondeterminism to Amplify Hardness Alexander Healy

    E-print Network

    Vadhan, Salil

    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

  10. Cryptographic Hardness for Learning Intersections of Halfspaces

    E-print Network

    Klivans, Adam

    Cryptographic Hardness for Learning Intersections of Halfspaces Adam R. Klivans University representation-independent hardness results for PAC learning intersections of halfspaces, a central concept class in computational learning theory. Our hardness results are derived from two public-key cryptosystems due to Regev

  11. Unified characterisations of resolution hardness measures

    E-print Network

    Kullmann, Oliver

    1 Unified characterisations of resolution hardness measures Olaf Beyersdorff 1 Oliver Kullmann 2 1;2 Hardness measures for resolution Historically first and best studied size of resolution proofs tree method for space again via width [Atserias & Dalmau 08] #12;3 Why hardness measures? Correspondence

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

    E-print Network

    Northern British Columbia, University of

    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

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

    E-print Network

    Jamieson, Bruce

    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

  14. 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

  15. Hard body amphiphiles at a hard wall JOSEPH M. BRADER1y

    E-print Network

    Schmidt, Matthias

    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

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

    NASA Astrophysics Data System (ADS)

    Osman, Sahin

    2007-11-01

    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.

  17. Valuing vaccination

    PubMed Central

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

    2014-01-01

    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

  18. Density functional approximation for van der Waals fluids: based on hard sphere density functional approximation

    NASA Astrophysics Data System (ADS)

    Zhou, Shi-Qi

    2007-04-01

    A universal theoretical approach is proposed which enables all hard sphere density functional approximations (DFAs) applicable to van der Waals fluids. The resultant DFA obtained by combining the universal theoretical approach with any hard sphere DFAs only needs as input a second-order direct correlation function (DCF) of a coexistence bulk fluid, and is applicable in both supercritical and subcritical temperature regions. The associated effective hard sphere density can be specified by a hard wall sum rule. It is indicated that the value of the effective hard sphere density so determined can be universal, i.e. can be applied to any external potentials different from the single hard wall. As an illustrating example, the universal theoretical approach is combined with a hard sphere bridge DFA to predict the density profile of a hard core attractive Yukawa model fluid influenced by diverse external fields; agreement between the present formalism's predictions and the corresponding simulation data is good or at least comparable to several previous DFT approaches. The primary advantage of the present theoretical approach combined with other hard sphere DFAs is discussed.

  19. The Hard Problem of Cooperation

    PubMed Central

    Eriksson, Kimmo; Strimling, Pontus

    2012-01-01

    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

  20. Hard Scattering Studies at Jlab

    SciTech Connect

    Harutyun Avagyan; Peter Bosted; Volker Burkert; Latifa Elouadrhiri

    2005-09-01

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

  1. Hard-disk fluid revisit

    E-print Network

    Hanqing Zhao; Hong Zhao

    2015-11-03

    We study the velocity and energy current autocorrelation functions in hard-disk fluid by large-scale simulations. The $t^{-1}$ long-time tail is reconfirmed for the former while is verified for latter. The validity of several essential hydrodynamics and kinetics predictions are checked with varying the disks density. The significant difference between the two autocorrelation functions are revealed. The long-time tail of the velocity autocorrelation is derived using an intuitive picture, based on which a unified formula of the velocity autocorrelation function is presented. The mechanisms are discussed by studying the relaxation property of the momentum and local current.

  2. Hard and Soft Safety Verifications

    NASA Technical Reports Server (NTRS)

    Wetherholt, Jon; Anderson, Brenda

    2012-01-01

    The purpose of this paper is to examine the differences between and the effects of hard and soft safety verifications. Initially, the terminology should be defined and clarified. A hard safety verification is datum which demonstrates how a safety control is enacted. An example of this is relief valve testing. A soft safety verification is something which is usually described as nice to have but it is not necessary to prove safe operation. An example of a soft verification is the loss of the Solid Rocket Booster (SRB) casings from Shuttle flight, STS-4. When the main parachutes failed, the casings impacted the water and sank. In the nose cap of the SRBs, video cameras recorded the release of the parachutes to determine safe operation and to provide information for potential anomaly resolution. Generally, examination of the casings and nozzles contributed to understanding of the newly developed boosters and their operation. Safety verification of SRB operation was demonstrated by examination for erosion or wear of the casings and nozzle. Loss of the SRBs and associated data did not delay the launch of the next Shuttle flight.

  3. Hard sphere packings within cylinders

    E-print Network

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

    2015-11-26

    The packing of hard spheres (HS) of diameter $\\sigma$ in a cylinder has been used to model experimental systems, such as fullerenes in nanotubes and colloidal wire assembly. Finding the densest packings of HS under this type of confinement, however, grows increasingly complex with the cylinder diameter, $D$. Little is thus known about the densest achievable packings for $D>2.873\\sigma$. In this work, we extend the identification of the packings up to $D=4.00\\sigma$ by adapting Torquato-Jiao's adaptive-shrinking-cell formulation and sequential-linear-programming (SLP) technique. We identify 17 new structures, almost all of them chiral. Beyond $D\\approx2.85\\sigma$, most of the structures consist of an outer shell and an inner core that compete for being close packed. In some cases, the shell adopts its own maximum density configuration, and the stacking of core spheres within it is quasiperiodic. In other cases, an interplay between the two components is observed, which may result in simple periodic structures. In yet other cases, the very distinction between core and shell vanishes, resulting in more exotic packing geometries, including some that are three-dimensional extensions of structures obtained from packing hard disks in a circle.

  4. Kinetics of hardness evolution during annealing of gamma-irradiated polycarbonate

    SciTech Connect

    Yeh, S. H.; Chen, P. Y.; Lee, Sanboh; Harmon, Julie

    2012-12-01

    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.

  5. Velocity and energy distributions in microcanonical ensembles of hard spheres

    E-print Network

    Enrico Scalas; Adrian T. Gabriel; Edgar Martin; Guido Germano

    2015-08-29

    In a microcanonical ensemble (constant $NVE$, hard reflecting walls) and in a molecular dynamics ensemble (constant $NVE\\mathbf{PG}$, periodic boundary conditions) with a number $N$ of smooth elastic hard spheres in a $d$-dimensional volume $V$ having a total energy $E$, a total momentum $\\mathbf{P}$, and an overall center of mass position $\\mathbf{G}$, the individual velocity components, velocity moduli, and energies have transformed beta distributions with different arguments and shape parameters depending on $d$, $N$, $E$, the boundary conditions, and possible symmetries in the initial conditions. This can be shown marginalizing the joint distribution of individual energies, which is a symmetric Dirichlet distribution. In the thermodynamic limit the beta distributions converge to gamma distributions with different arguments and shape or scale parameters, corresponding respectively to the Gaussian, i.e., Maxwell-Boltzmann, Maxwell, and Boltzmann or Boltzmann-Gibbs distribution. These analytical results agree with molecular dynamics and Monte Carlo simulations with different numbers of hard disks or spheres and hard reflecting walls or periodic boundary conditions. The agreement is perfect with our Monte Carlo algorithm, which acts only on velocities independently of positions with the collision versor sampled uniformly on a unit half sphere in $d$ dimensions, while slight deviations appear with our molecular dynamics simulations for the smallest values of $N$.

  6. Measurements of the hard-x-ray reflectivity of iridium

    SciTech Connect

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

    2007-01-10

    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.

  7. Specific Energy of Hard Coal Under Load

    NASA Astrophysics Data System (ADS)

    Bogusz, Anna; Bukowska, Miros?awa

    2015-03-01

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

  8. Effect of Substrates on Film Hardness Measurements of Nanometer Thick Amorphous Carbon Films

    NASA Astrophysics Data System (ADS)

    Akasaka, Hiroki; Ito, Hiroki; Nakano, Masayuki; Ohshio, Shigeo; Saitoh, Hidetoshi

    Amorphous carbon film (a-C:H) applications, such as hard disks, require films with nanometer thicknesses. In an indentation test, the obtained hardness values of these films are affected by substrates. On the indentation tests, we studied the effect of substrate hardness on films less than 200 nm in thickness. a-C:H and Si doped a-C:H (a-C:Si:H) films were deposited by electron cyclotron resonance plasma chemical vapor deposition onto aluminum (Al) and silicon (Si) substrates. The film thicknesses were approximately 140 nm. The hardnesses of the a-C:H film and substrates were obtained using a high-resolution indentation tester (pico-dentor) with a Vickers tip whose depth resolution was 0.04 nm. Maximum indentation loads were varied from 0.01 to 0.5 mN. The Martens hardnesses of films on the Al and Si substrates were 600 and 7000 N/mm2, respectively. On the a-C:Si:H film deposited on the Al substrate, the hardnesses increased from 1600 to 3900 N/mm2 with decreasing indentation load. The hardnesses of the films deposited on the Si substrate decreased from 5300 to 3500 N/mm2 when the maximum indentation loads were reduced. The effect of the substrates increased with the maximum load increasing. From these findings, the actual hardness value was determined to be 3600 N/mm2. These results indicate that the high-resolution indentation test achieved hardness estimations for nanometer-thick films with certain hardnesses.

  9. [Keeping quality of hard boiled eggs].

    PubMed

    Partmann, W; Wedler, A

    1979-09-01

    Only a few and contradictory results are available on the storage stability of hard boiled eggs which are of considerable importance for institutional feeding. Therefore four storage experiments on about 500 hard boiled eggs each were carried out and chemical and sensorial changes occurring during storage investigated. The one-day-old eggs of the same origin were boiled for 17 minutes under standard conditions and subsequently stored in air at a relative humidity between 73 and 85% at 4 degrees C (experiment No. 1), at 20 degrees C (experiments No. 2 and 3) and in pure carbon dioxide at 20 degrees C (experiment No. 4). Immediately after boiling, the eggs used for experiments No. 3 were dipped into coloured resin for egg shells (natural Manila-Kopa; dissolved in ethanol and stained with "Acillantechtgrün). Losses in weight during storages were distincly lower in the lacquered eggs than in the non-lacquered samples otherwise treated in the same manner. The weight decrease caused by the loss of water was extraordinarily high in pure CO2 and is due mainly the the decrease of the pH in the egg whites caused by the uptake of CO2. A few days after boiling the concentration of the free amino acids reached approximately the same level in albumen and yolk and remained practically constant over the following 3 weeks. For the breakdown of lecithine in yolk determined according to Grossfeld and Peter, a "deterioration quotient" of 6, like in unboiled eggs, was fixed as the limit value for unspoiled condition. Accordingly a possible storage time of 3 to 4 weeks resulted for the eggs stored at 4 degrees C and for the eggs treated with stained resin. The non-lacquered eggs stored in air or in CO2 at 20 degrees C reached the critical value in about 10 days. From the vitamins A, B1 and B2 only vitamin A showed considerable losses during storage. On the basis of the microbiological (3) and chemical findings and of the sensorial evaluation of colour, consistency, odour and taste of egg whites and yolks, the following storage times were determined for eggs in the quality class "saleable" requiring an overall rating not lower than 6 (satisfactory): 14 to 16 days, for non-lacquered eggs stored at 4 degrees C and for lacquered eggs at 20 degrees C whereas 5 days were found to be the maximum storage time for untreated eggs stored at 20 degrees C. If boiled eggs are stored in pure carbon dioxide at 20 degrees C, a distinct quality loss is observed already after a few days. PMID:575006

  10. Value Stream Mapping Value Stream Mapping VSM

    E-print Network

    Laksanacharoen, Sathaporn

    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

  11. Theory of Hard Diffraction and Rapidity Gaps

    E-print Network

    Vittorio Del Duca

    1995-06-18

    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).

  12. One-dimensional hard rod fluid in a disordered porous medium: scaled particle theory

    E-print Network

    M. Holovko; T. Patsahan; W. Dong

    2012-07-12

    The scaled particle theory is applied to a description of thermodynamic properties of one-dimensional hard rod fluid in disordered porous media. To this end, we extended the SPT2 approach, which had been developed previously. Analytical expressions are obtained for the chemical potential and pressure of a hard-rod fluid in hard rod and overlapping hard rod matrices. A series of new approximations for SPT2 are proposed. It is shown that apart from two well known porosities such as geometrical porosity and specific probe particle porosity, a new type of porosity defined by the maximum value of packing fraction of fluid particles in porous medium should be taken into account. The grand canonical Monte-Carlo simulations are performed to verify the accuracy of the SPT2 approach in combination with the new approximations. It is observed that the theoretical description proposed in this study essentially improves the results up to the highest values of fluid densities.

  13. Hard-gapped Holographic Superconductors

    E-print Network

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

    2009-12-05

    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.

  14. Plasma-assisted growth of bilayer silicon-containing coatings for hardness and corrosion resistance

    NASA Astrophysics Data System (ADS)

    Xiao, Z. G.; Mantei, T. D.

    2004-07-01

    Hard corrosion-resistant bilayer coatings were grown in a high-density microwave electron cyclotron resonance discharge. The bilayer coatings consist of a relatively soft (0.6-1.5 GPa) polymer-like coating as the adherent bottom layer and a much harder (8-12 GPa) top layer. The polymer underlayers were grown from 100% octamethylcyclotetrasiloxane (OMCTS) while the hard top layer was either silicon dioxide grown from OMCTS in an oxygen plasma or silicon nitride grown from hexamethyldisiloxane in an ammonia plasma. The bilayer structures combined high surface hardness values with good corrosion resistance, surviving 1800-2600 h in an ASTM B117 salt-fog corrosion test. .

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  16. Interfacial free energy of a hard-sphere fluid in contact with curved hard surfaces

    E-print Network

    Laird, Brian Bostian; Hunter, Allie; Davidchack, Ruslan L.

    2012-12-20

    Using molecular-dynamics simulation, we have calculated the interfacial free energy ? between a hard-sphere fluid and hard spherical and cylindrical colloidal particles, as functions of the particle radius R and the fluid packing fraction ?=??3...

  17. Effect of gamma radiation on micromechanical hardness of lead-free solder joint

    NASA Astrophysics Data System (ADS)

    Paulus, Wilfred; Rahman, Irman Abdul; Jalar, Azman; Kamil, Insan; Yusoff, Wan Yusmawati Wan; Bakar, Maria Abu

    2015-09-01

    Lead-free solders are important material in nano and microelectronic surface mounting technology for various applications in bio medicine, environmental monitoring, spacecraft and satellite instrumentation. Nevertheless solder joint in radiation environment needs higher reliability and resistance to any damage caused by ionizing radiations. In this study a lead-free 99.0Sn0.3Ag0.7Cu wt.% (SAC) solder joint was developed and subjected to various doses of gamma radiation to investigate the effects of the ionizing radiation to micromechanical hardness of the solder. Averaged hardness of the SAC joint was obtained from nanoindentation test. The results show a relationship between hardness values of indentations and the increment of radiation dose. Highest mean hardness, 0.2290 ± 0.0270 GPa was calculated on solder joint which was exposed to 5 Gray dose of gamma radiation. This value indicates possible radiation hardening effect on irradiated solder. The hardness gradually decreased to 0.1933 ± 0.0210 GPa and 0.1631 ± 0.0173 GPa when exposed to doses 50 and 500 gray respectively. These values are also lower than the hardness of non irradiated sample which was calculated as 0.2084 ± 0.0.3633 GPa indicating possible radiation damage and needs further related atomic dislocation study.

  18. Implementing QML for radiation hardness assurance

    NASA Astrophysics Data System (ADS)

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

    1990-12-01

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

  19. Geometric optimization for radiation hardness assurance

    NASA Astrophysics Data System (ADS)

    Northum, J.; Guetersloh, S.

    The probability of a single event effect occurring is generally a function of the energy deposited in a sensitive volume, which is typically expressed as the absorbed dose in that volume. For short segments of high energy particle tracks, the dose due to a single event is proportional to the chord length through the sensitive volume. Thus, the distribution of dose in chord length is likely to relate to the probability of single event effects. For various geometries, a differential chord length distribution was generated and from this the dose distribution, frequency mean chord length, and dose mean chord length were calculated. In every case, the dose mean chord length was greater than the frequency mean chord length by a minimum of 26% and increased with the eccentricity of the volume. The large value of the dose mean chord length relative to the frequency mean chord length demonstrates the need to consider rare, long-chord-length crossings in radiation hardness testing, despite their relatively low probability of occurrence.

  20. Successes and failures with hard probes

    E-print Network

    M. J. Tannenbaum

    2009-01-09

    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.

  1. Mems and Nano Possible 4th year specializa7ons

    E-print Network

    Smy, Tom

    of lathe bits, mills and drills But all are basically scraping & gouging away material Micro-machining: 1: It is incredibly hard and strong! Knoop Hardness Index (kg/mm2) Diamond 7000 Silicon Carbide 2480 Silicon 1150

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

    E-print Network

    MacLennan, Bruce

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

  3. Estimate of snow density knowing grain and share hardness

    NASA Astrophysics Data System (ADS)

    Valt, Mauro; Cianfarra, Paola; Cagnati, Anselmo; Chiambretti, Igor; Moro, Daniele

    2010-05-01

    Alpine avalanche warning services produces, weekly, snow profiles. Usually such profiles are made in horizontal snow fields, homogenously distributed by altitude and climatic micro-areas. Such profile allows grain shape, dimension and hardness (hand test) identification. Horizontal coring of each layer allows snow density identification. Such data allows the avalanche hazard evaluation and an estimation of the Snow Water Equivalent (SWE). Nevertheless the measurement of snow density, by coring, of very thin layers (less than 5 cm of thickness) is very difficult and are usually not measured by snow technicians. To bypass such problems a statistical analysis was performed to assign density values also to layers which cannot be measured. This system allows, knowing each layer thickness and its density, to correctly estimate SWE. This paper presents typical snow density values for snow hardness values and grain types for the Eastern Italian Alps. The study is based onto 2500 snow profiles with 17000 sampled snow layers from the Dolomites and Venetian Prealps (Eastern Alps). The table of typical snow density values for each grain type is used by YETI Software which elaborate snow profiles and automatically evaluate SWE. This method allows a better use of Avalanche Warning Services datasets for SWE estimation and local evaluation of SWE yearly trends for each snow field.

  4. 21 CFR 133.150 - Hard cheeses.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Hard cheeses. 133.150 Section 133.150 Food and... CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.150 Hard cheeses. (a) The cheeses for which definitions and standards of identity...

  5. 21 CFR 133.150 - Hard cheeses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Hard cheeses. 133.150 Section 133.150 Food and... CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.150 Hard cheeses. (a) The cheeses for which definitions and standards of identity...

  6. 21 CFR 133.150 - Hard cheeses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Hard cheeses. 133.150 Section 133.150 Food and... CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.150 Hard cheeses. (a) The cheeses for which definitions and standards of identity...

  7. Universality, Hardness, Engineering, and Messiness Cristopher Moore

    E-print Network

    Moore, Cris

    Universality, Hardness, Engineering, and Messiness Cristopher Moore Santa Fe Institute Monday, May are designed by a clever adversary to encode hard problems A good assumption in cryptography, but not in most) crosses a critical threshold, a sudden drop from satisfiability to unsatisfiability Like water freezing

  8. HARD SPRING WHEAT TECHNICAL COMMITTEE 2007 CROP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve experimental lines of hard spring wheat were grown at up to five locations in 2007 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Samples of wheat were submitted through the Wheat Quality Council and processed and milled at the USDA Hard Red Spri...

  9. 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...

  10. Xylem Monoterpenes of Some Hard Pines

    E-print Network

    Xylem Monoterpenes of Some Hard Pines of Western North ' America: three studies Forest Service August 1982 #12;Xylem Monoterpenes of Some Hard Pines of Western North America: three studies Richard H Size 6 Chromatographic Analysis on Short Column 7 References 7 #12;IN BRIEF... Smith, Richard H. Xylem

  11. Hard Spring Wheat Technical Committee 2009 Crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. Classic Nintendo Games are (Computationally) Hard

    E-print Network

    Demaine, Erik

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

  13. Why Are Drugs So Hard to Quit?

    MedlinePLUS Videos and Cool Tools

    ... count__/__total__ Find out why Close Why Are Drugs So Hard to Quit National Institute on Drug Abuse (NIDA/NIH) Subscribe Subscribed Unsubscribe 3,542 ... again later. Uploaded on Feb 7, 2012 Quitting drugs is hard because addiction is a brain disease. ...

  14. Electromagnetic Scattering from Foliage Camouflaged Hard Targets,

    E-print Network

    Sarabandi, Kamal

    Electromagnetic Scattering from Foliage Camouflaged Hard Targets, in VHF-band Mojtaba Dehmollaian@eecs.umich.edu Abstract A hybrid target-foliage model is developed to investigate the scattering be- havior of hard on single scattering theory for propagation through and scattering from the forest [1] and an FDTD technique

  15. Theoretical analysis of tablet hardness prediction using chemoinformetric near-infrared spectroscopy.

    PubMed

    Tanabe, Hideaki; Otsuka, Kuniko; Otsuka, Makoto

    2007-07-01

    In order to clarify the theoretical basis of the variability in the measurement of tablet hardness by compression pressure, NIR spectroscopic methods were used to predict tablet hardness of the formulations. Tablets (200 mg, 8 mm in diameter) consisting of berberine chloride, lactose, and potato starch were formed at various compression pressures (59, 78, 98, 127, 195 MPa). The hardness and the distribution of micropores were measured. The reflectance NIR spectra of various compressed tablets were used as a calibration set to establish a calibration model to predict tablet hardness by principal component regression (PCR) analysis. The distribution of micropores was shifted to a smaller pore size with increasing compression pressure. The total pore volume of tablets decreased as the compression pressure increased. The hardness increased as the compression pressure increased. The hardness could be predicted using a calibration model consisting of 7 principal components (PCs) obtained by PCR. The relationship between the predicted and the actual hardness values exhibited a straight line, an R(2) of 0.925. In order to understand the theoretical analysis (scientific background) of calibration models used to evaluate tablet hardness, the standard error of cross validation (SEV) values, the loading vectors of each PC and the regression vector were investigated. The result obtained with the calibration models for hardness suggested that the regression vector might involve physical and chemical factors. In contrast, the porosity could be predicted using a calibration model composed of 2 PCs. The relationship between the predicted and the actual total pore volume showed a straight line with R(2) = 0.801. The regression vector of the total pore volume might be due to physical factors. PMID:17625330

  16. Thermal spray coatings replace hard chrome

    SciTech Connect

    Schroeder, M.; Unger, R.

    1997-08-01

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

  17. A microarray analysis of wheat grain hardness.

    PubMed

    Clarke, Bryan; Rahman, Sadequr

    2005-05-01

    Grain hardness is an important quality characteristic of wheat grain, and considerable research effort has focused on characterising the genetic and biochemical basis underlying the hardness phenotype. Previous research has shown that the predominant difference between hard and soft seeds is linked to the puroindoline (PIN) proteins. In this study the near-isogenic lines of Heron and Falcon, which differ only in the grain hardness character, were compared using a cDNA microarray consisting of approximately 5,000 unique cDNA clones that were isolated from wheat and barley endosperm tissue. Our analysis showed that major differences in gene expression were evident for puroindoline-a (Pina), with a minor but not consistent change in the expression of puroindoline-b (Pinb). These observations were confirmed using a 16,000 unique cDNA microarray in a comparison of hard wheats with either the Pina null or Pinb mutation. PMID:15806348

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

    E-print Network

    Mingcheng Yang; Hongru Ma

    2008-06-23

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

  19. Exclusive, Hard Diffraction in QCD

    NASA Astrophysics Data System (ADS)

    Freund, Andreas

    1999-03-01

    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 ˜ 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.

  20. A survey of hard spectrum ROSAT sources 1: X-ray source catalogue

    E-print Network

    M. J. Page; J. P. D. Mittaz; F. J. Carrera

    2000-06-24

    We present a catalogue of 147 serendipitous X-ray sources selected to have hard spectra (alpha 10 times as much effective area to hard sources as it has to soft sources above a 0.5 - 2 keV flux level of 10^-14 erg/cm^2/s. The distribution of best fit spectral slopes of the hard sources suggests that a typical ROSAT hard source in our survey has a spectral slope alpha ~0. The hard sources have a steep number flux relation (dN/dS propto S^-gamma with a best fit value of gamma = 2.72 +- 0.12) and make up about 15% of all 0.5 - 2 keV sources with S > 10^-14 erg/cm^2/s. If their N(S) continues to fainter fluxes, the hard sources will comprise ~ 40% of sources with 5 10^-15 < S < 10^-14. The population of hard sources can therefore account for the harder average spectra of ROSAT sources with S < 10^-14. They probably make a strong contribution to the X-ray background at faint fluxes and could be the solution to the X-ray background spectral paradox.

  1. Analysis of Hard Thin Film Coating

    NASA Technical Reports Server (NTRS)

    Shen, Dashen

    1998-01-01

    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.

  2. Analysis of Hard Thin Film Coating

    NASA Technical Reports Server (NTRS)

    Shen, Dashen

    1998-01-01

    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.

  3. Characterization of Hard Piezoelectric Lead-Free Ceramics

    PubMed Central

    Zhang, Shujun; Lim, Jong Bong; Lee, Hyeong Jae; Shrout, Thomas R.

    2010-01-01

    K4CuNb8O23 doped K0.45Na0.55NbO3 (KNN-KCN) ferroelectric ceramics were found to exhibit asymmetrical polarization hysteresis loops, related to the development of an internal bias field. The internal bias field is believed to be the result of defect dipoles of acceptor ions and oxygen vacancies, which lead to piezoelectric “hardening” effect, by stabilizing and pinning of the domain wall motion. The dielectric loss for the hard lead-free piezoelectric ceramic was found to be 0.6%, with mechanical quality factors Q on the order of >1500. Furthermore, the piezoelectric properties were found to decrease and the coercive field increased, when compared with the undoped material, exhibiting a typical characteristic of “hard” behavior. The temperature usage range was limited by the polymorphic phase transition temperature, being 188°C. The full set of material constants was determined for the KNN-KCN materials. Compared with conventional hard PZT ceramics, the lead-free possessed lower dielectric and piezoelectric properties; however, comparable values of mechanical Q, dielectric loss, and coercive fields were obtained, making acceptor modified KNN based lead-free piezoelectric material promising for high-power applications, where lead-free materials are desirable. PMID:19686966

  4. A fundamental measure theory for the sticky hard sphere fluid

    NASA Astrophysics Data System (ADS)

    Hansen-Goos, Hendrik; Wettlaufer, J. S.

    2011-01-01

    We construct a density functional theory (DFT) for the sticky hard sphere (SHS) fluid which, like Rosenfeld's fundamental measure theory (FMT) for the hard sphere fluid [Y. Rosenfeld, Phys. Rev. Lett. 63, 980 (1989)], is based on a set of weighted densities and an exact result from scaled particle theory (SPT). It is demonstrated that the excess free energy density of the inhomogeneous SHS fluid ? _{SHS} is uniquely defined when (a) it is solely a function of the weighted densities from Kierlik and Rosinberg's version of FMT [E. Kierlik and M. L. Rosinberg, Phys. Rev. A 42, 3382 (1990)], (b) it satisfies the SPT differential equation, and (c) it yields any given direct correlation function (DCF) from the class of generalized Percus-Yevick closures introduced by Gazzillo and Giacometti [J. Chem. Phys. 120, 4742 (2004)]. The resulting DFT is shown to be in very good agreement with simulation data. In particular, this FMT yields the correct contact value of the density profiles with no adjustable parameters. Rather than requiring higher order DCFs, such as perturbative DFTs, our SHS FMT produces them. Interestingly, although equivalent to Kierlik and Rosinberg's FMT in the case of hard spheres, the set of weighted densities used for Rosenfeld's original FMT is insufficient for constructing a DFT which yields the SHS DCF.

  5. A position sensitive phoswich hard X-ray detector system

    NASA Technical Reports Server (NTRS)

    Dean, A. J.; Hanson, C. G.; Hopkins, C. J.; Lewis, R. A.; Fraser-Mitchell, J.

    1985-01-01

    A prototype position sensitive phoswich hard X-ray detector, designed for eventual astronomical usage, was tested in the laboratory. The scintillation crystal geometry was designed on the basis of a Monte Carlo simulation of the internal optics and includes a 3mm thick NaI(T1) primary X-ray detector which is actively shielded by a 20 mm thick CsI(T1) scintillation crystal. This phoswich arrangement is viewed by a number two inch photomultipliers. Measured values of the positional and spectral resolution of incident X-ray photons are compared with calculation.

  6. One-dimensional gas of hard needles

    E-print Network

    Kardar, Mehran

    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 ...

  7. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...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,...

  8. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...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...

  9. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...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...

  10. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...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,...

  11. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...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,...

  12. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...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...

  13. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...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,...

  14. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...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...

  15. 7 CFR 201.57 - Hard seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...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...

  16. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...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,...

  17. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...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,...

  18. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...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,...

  19. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...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,...

  20. 7 CFR 201.21 - Hard seed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...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,...

  1. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...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,...

  2. Automated radiation hard ASIC design tool

    NASA Technical Reports Server (NTRS)

    White, Mike; Bartholet, Bill; Baze, Mark

    1993-01-01

    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.

  3. Why Is It So Hard to Quit?

    MedlinePLUS

    ... back on alcohol. It’s hard to have will power and stay focused on your commitment when you’ ... Articles 1 Understanding Blood Pressure Readings 2 Target Heart Rates 3 What are the Symptoms of High Blood ...

  4. Classic Nintendo Games Are (Computationally) Hard

    E-print Network

    Aloupis, Greg

    2014-01-01

    We prove NP-hardness results for five of Nintendo’s largest video game franchises: Mario, Donkey Kong, Legend of Zelda, Metroid, and Pokemon. Our results apply to generalized versions of Super Mario Bros. 1, 3, Lost Levels, ...

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

    E-print Network

    A. Astillero; A. Santos

    2005-08-30

    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

  6. Laser Ablatin of Dental Hard Tissue

    SciTech Connect

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

    2007-07-31

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

  7. Density Functional Theory for Hard Polyhedra

    NASA Astrophysics Data System (ADS)

    Marechal, Matthieu; Löwen, Hartmut

    2013-03-01

    Using the framework of geometry-based fundamental-measure theory, we develop a classical density functional for hard polyhedra and their mixtures and apply it to inhomogeneous fluids of Platonic solids near a hard wall. As revealed by Monte Carlo simulations, the faceted shape of the polyhedra leads to complex layering and orientational ordering near the wall, which is excellently reproduced by our theory. These effects can be verified in real-space experiments on polyhedral colloids.

  8. A Novel Approach to Hardness Testing

    NASA Technical Reports Server (NTRS)

    Spiegel, F. Xavier; West, Harvey A.

    1996-01-01

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

  9. Radiation-Hard Quartz Cerenkov Calorimeters

    SciTech Connect

    Akgun, U.; Onel, Y.

    2006-10-27

    New generation hadron colliders are going to reach unprecedented energies and radiation levels. Quartz has been identified as a radiation-hard material that can be used for Cerenkov calorimeters of the future experiments. We report from the radiation hardness tests performed on quartz fibers, as well as the characteristics of the quartz fiber and plate Cerenkov calorimeters that have been built, designed, and proposed for the CMS experiment.

  10. Page 1 of 2 Hard Drive & Magnetic Tape Destruction Service Hard Drive & Magnetic Tape Destruction Request Form

    E-print Network

    Mountziaris, T. J.

    Page 1 of 2 Hard Drive & Magnetic Tape Destruction Service Hard Drive & Magnetic Tape Destruction Request Form Departmental Representative (e.g., tape, hard disk) Manufacturer (e.g., Seagate, Maxtor) Model

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

    NASA Astrophysics Data System (ADS)

    Y?lmaz, Nurdan Güne?

    2011-11-01

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

  12. RAD hard PROM design study

    NASA Technical Reports Server (NTRS)

    1981-01-01

    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.

  13. The Value of Reciprocity

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  14. Hard evidence on soft skills?

    PubMed Central

    Heckman, James J.; Kautz, Tim

    2012-01-01

    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

  15. Calculation of ionization potential and chemical hardness: A comparative study of different methods

    NASA Astrophysics Data System (ADS)

    Shankar, R.; Senthilkumar, K.; Kolandaivel, P.

    The suitability of ab initio and density functional theory (DFT) methods for an accurate determination of ionization potential and chemical hardness is the subject of systematic analysis for a panel of molecules. Comparison of experimental ionization potential values with theoretical results indicates that using orbital energies obtained from the so-called statistical average of orbital potential (SAOP) model exchange correlation potential in Koopman's theorem is an efficient method to evaluate the correct ionization potentials. Experimental ionization potential and electron affinity values have been used to calculate the absolute chemical hardness. Comparative results show that the chemical hardness values calculated by using Hartree-Fock orbital energies in Koopman's theorem are sufficiently good rather than Möller-Plesset second order perturbation method and DFT-generalized gradient approximation (GGA) exchange correlation functional orbital energies. A new method given by Tozer et al. (J Phys Chem A 2005, 109, 8923) to calculate the chemical hardness works well with the orbital energies of DFT-GGA functionals together with the ionization potential values calculated from SAOP orbital energies.

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

    ERIC Educational Resources Information Center

    Rutkowski, David; Engel, Laura C.

    2010-01-01

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

  17. Note: equation of state and the freezing point in the hard-sphere model.

    PubMed

    Robles, Miguel; López de Haro, Mariano; Santos, Andrés

    2014-04-01

    The merits of different analytical equations of state for the hard-sphere system with respect to the recently computed high-accuracy value of the freezing-point packing fraction are assessed. It is found that the Carnahan-Starling-Kolafa and the branch-point approximant equations of state yield the best performance. PMID:24712819

  18. Email (Hard Rain) 1. CyberCIEGE Email

    E-print Network

    Email (Hard Rain) 1. CyberCIEGE Email CyberCIEGE is an information assurance (IA) training tool the "Advanced VPNs" scenario prior to playing this scenario. October 26, 2009 #12;Email (Hard Rain) Figure 1: Select Hard Rain and Click Play Select the "Hard Rain" scenario from the scenario list. Then click

  19. Hard-Core Unemployment: A Selected, Annotated Bibliography.

    ERIC Educational Resources Information Center

    Cameron, Colin, Comp.; Menon, Anila Bhatt, Comp.

    This annotated bibliography contains references to various films, articles, and books on the subject of hard-core unemployment, and is divided into the following sections: (1) The Sociology of the Hard-Core Milieu, (2) Training Programs, (3) Business and the Hard-Core, (4) Citations of Miscellaneous References on Hard-Core Unemployment, (5)…

  20. The Hardness of 3-Uniform Hypergraph Coloring Irit Dinur

    E-print Network

    Smyth, Clifford

    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

  1. Fixed Parameter hardness in opt Mohammad T. Hajiaghayi

    E-print Network

    Kortsarz, Guy

    Fixed Parameter hardness in opt Mohammad T. Hajiaghayi Rohit Khandekar Guy Kortsarz Abstract)-FPT-inapproximable (or, (r, t)- FPT-hard) when the problem does not admit an (r, t)-FPT-approximation algorithm to approximation in opt. A hardness (in the usual sense) is (also) a hardness in opt if k equals opt(I) some

  2. Hard X-ray properties of magnetic cataclysmic S. Scaringi

    E-print Network

    Norton, Andrew J.

    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

  3. On the Exact Cryptographic Hardness of Finding a Nash Equilibrium

    E-print Network

    International Association for Cryptologic Research (IACR)

    On the Exact Cryptographic Hardness of Finding a Nash Equilibrium Sanjam Garg Omkant Pandey Akshayaram Srinivasan Abstract The exact hardness of computing a Nash equilibrium is a fundamental open is to reduce the hardness of PPAD to the hardness of problems used in cryptography. Bitansky, Paneth, and Rosen

  4. On the Hardness of Approximating the Chromatic Number Sanjeev Khanna

    E-print Network

    Khanna, Sanjeev

    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

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

    E-print Network

    Vadhan, Salil

    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

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

    E-print Network

    Vadhan, Salil

    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

  7. The Hardness of 3-Uniform Hypergraph Coloring Irit Dinur

    E-print Network

    Regev, Oded

    The Hardness of 3-Uniform Hypergraph Coloring Irit Dinur Oded Regev Clifford Smyth August 27, 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

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

    ERIC Educational Resources Information Center

    Phillips, D. C.

    2014-01-01

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

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

    ERIC Educational Resources Information Center

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

    2005-01-01

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

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

    E-print Network

    MacLennan, Bruce

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

  11. 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 ...

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

    PubMed

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

    2013-06-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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.

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

    PubMed

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

    2014-02-01

    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

  15. Potential Health Impacts of Hard Water

    PubMed Central

    Sengupta, Pallav

    2013-01-01

    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

  16. Hysteresis of misaligned hard-soft grains

    NASA Astrophysics Data System (ADS)

    Wan, X. L.; Zhao, G. P.; Zhang, X. F.; Xia, J.; Zhang, X. C.; Morvan, F. J.

    2016-01-01

    The demagnetization process in hard/soft multilayer systems has been investigated systematically within a self-contained micromagnetic model when a deviation angle ? between the easy axis and the applied field exists. Hysteresis loops, spin distributions and energy products have been calculated with a finite hard layer thickness th. Both remanence and coercivity of the multilayer system decrease as ? increases, leading to a significant decrease of the maximum energy product. A 30° deviation of the easy axis could result in a drop of the maximum energy product by more than 60%, which offers a possible explanation on the large discrepancy between the experimental and theoretical energy products. The effect of the finite hard layer thickness on the demagnetization process is important, which can only be ignored when th is large enough.

  17. Hard template synthesis of metal nanowires

    PubMed Central

    Kawamura, Go; Muto, Hiroyuki; Matsuda, Atsunori

    2014-01-01

    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

  18. Potential health impacts of hard water.

    PubMed

    Sengupta, Pallav

    2013-08-01

    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

  19. Erosion testing of hard materials and coatings

    SciTech Connect

    Hawk, Jeffrey A.

    2005-04-29

    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).

  20. Structural precursor to freezing in the hard-disk and hard-sphere systems Thomas M. Truskett,1

    E-print Network

    Structural precursor to freezing in the hard-disk and hard-sphere systems Thomas M. Truskett,1, namely, the hard-disk and hard-sphere fluids, exhibit a structural precursor to the freezing transition of the two-dimensional fluid configurations in the vicinity of the freezing transition reveals

  1. Hard Determinism and the Moral "Ought"

    E-print Network

    Kuo, Lenore

    stream_size 26754 stream_content_type text/plain stream_name auslegung.v14.n01.037-047.pdf.txt stream_source_info auslegung.v14.n01.037-047.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 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...

  2. Hard-thermal-loop QED thermodynamics

    E-print Network

    Nan Su; Jens O. Andersen; Michael Strickland

    2009-11-24

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

  3. The Value in Value Management: A Dialogue.

    ERIC Educational Resources Information Center

    Huish, John; van der Have, Pieter J.

    1998-01-01

    Details the value management process in which a group of diverse, disciplined professionals work together to design a better facility for a given budget. Areas addressed include a definition of value management, some derived benefits, negative aspects, projects best suited to this method, specific results, who pays, who is involved, scaled-down…

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

    USGS Publications Warehouse

    Krumhardt, Andrea P.

    1979-01-01

    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)

  5. HEPGEN - generator for hard exclusive leptoproduction

    E-print Network

    A. Sandacz; P. Sznajder

    2012-07-02

    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.

  6. Hard Times: Philosophy and the Fundamentalist Imagination

    ERIC Educational Resources Information Center

    Allsup, Randall Everett

    2005-01-01

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

  7. Soft Skills, Hard Program for STEM

    E-print Network

    Wu, Mingshen

    Soft Skills, Hard Science: A Program for STEM Students with Disabilities Laura McCullough, Kathleen Grant focused on improving job placement rates for STEM students with Disabilities 2 #12;Employment gap STEM majors with disabilities are less likely to gain employment than their counterparts without

  8. Hard Spring Wheat Technical Committee 2006 Crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeders’ experimental lines of wheat are evaluated for overall quality before being released for commercial production. The Hard Spring Wheat Technical Committee provides milling and baking quality data on breeders’ experimental lines of wheat that are annually submitted to the Wheat Quality Counc...

  9. Crystallization of hard spheres under gravity

    E-print Network

    Yan Levin

    2000-07-17

    We present a simple argument to account for crystallization of hard spheres under the action of a gravitational field. The paper attempts to bridge the gap between two communities of scientists, one working on granular materials and the other on inhomogeneous liquid state theory.

  10. Hard thermal loops in static external fields

    E-print Network

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

    2009-02-04

    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.

  11. Hard thermal loops in static background fields

    E-print Network

    F. T. Brandt; J. Frenkel; J. B. Siqueira

    2013-10-11

    We discuss the high temperature behavior of retarded thermal loops in static external fields. We employ an analytic continuation of the imaginary time formalism and use a spectral representation of the thermal amplitudes. We show that, to all orders, the leading contributions of static hard thermal loops can be directly obtained by evaluating them at zero external energies and momenta.

  12. Radiation-Hardness Data For Semiconductor Devices

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  13. Hard Cider Varieties Suitable for Northern

    E-print Network

    /lb. of apples Cider Category 3326 14.2 0.07 L Sweet #12;Browns Apple · Late-season, large apple · Striped red) Avg. Brix Juice/lb. of apples Cider Category 3719 13.6 0.15 L Sharp #12;Brown Snout · Late Center #12;Hard Cider Planting at NWMHRC · Planted in 2001 and 2002 · First apples in fall 2004 ­ Most

  14. Registration of ‘Sprinter’ hard red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Wooden Geometric Puzzles: Design and Hardness Proofs

    E-print Network

    Utrecht, Universiteit

    Wooden Geometric Puzzles: Design and Hardness Proofs Helmut Alt Hans L. Bodlaender Marc van Kreveld Technical Report UU-CS-2007-009 www.cs.uu.nl ISSN: 0924-3275 #12;Wooden Geometric Puzzles: Design, Utrecht University. {hansb,marc,gerard}@cs.uu.nl Abstract We discuss some new geometric puzzles

  16. Wooden Geometric Puzzles: Design and Hardness Proofs

    E-print Network

    Utrecht, Universiteit

    Wooden Geometric Puzzles: Design and Hardness Proofs Helmut Alt Hans L. Bodlaender Marc van Kreveld Technical Report UU­CS­2007­009 www.cs.uu.nl ISSN: 0924­3275 #12; Wooden Geometric Puzzles: Design puzzles and the complexity of their extension to arbitrary sizes. For gate puzzles and two­layer puzzles

  17. Registration of 'Advance' Hard Red Spring Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grower and end-user acceptance of new hard red spring wheat (HRSW; Triticum aestivum L.) cultivars is largely contingent on satisfactory agronomic performance, end-use quality potential, and disease resistance levels. Additional characteristics, such as desirable plant height, can also help to maxi...

  18. Sustaining Transformation: "Resiliency in Hard Times"

    ERIC Educational Resources Information Center

    Guarasci, Richard; Lieberman, Devorah

    2009-01-01

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

  19. Factorization and Scaling in Hard Diffraction

    E-print Network

    K. Goulianos

    1997-08-02

    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.

  20. Carry Hard ICBM basing: A technical assessment

    SciTech Connect

    Harvey, J.R.; Schaffer, A.B.; Speed, R.; Todaro, A.F.

    1989-11-15

    Carry Hard is a deceptive, multiple-aimpoint ICBM basing concept in which hardened, encapsulated missiles are shuttled among several thousand, low-cost, water-filled vertical shelters. Since most of the essential launch and operational support equipment is carried with the missile (not provided with each shelter), the overall system costs are reduced. High system hardness permits relatively close shelter spacing, which in turn allows Carry Hard to be deployed on a comparatively small piece of land (a few hundred square miles) that could be removed from public access. Controlled access to the deployment area helps in maintaining concealment of the missiles among the shelters. If concealment is successfully maintained, the system is believed to be survivable against plausible Soviet threats, regardless of whether attack-warning information is received or acted upon. Thus, Carry Hard holds high promise as a feasible, affordable, and survivable means of ICBM deployment, and a high priority should be given to developing the concept to the point that an informed decision on full-scale engineering development can be made. 33 refs., 4 figs., 5 tabs.

  1. DIELECTRIC SPECTROSCOPY OF HARD RED WINTER WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. PROTEIN TEMPLATES IN HARD TISSUE ENGINEERING

    PubMed Central

    George, Anne; Ravindran, Sriram

    2010-01-01

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

  3. Rad-Hard Microcontroller for Space Applications

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

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

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

    DOEpatents

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

    1996-01-01

    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.

  5. The BQP-hardness of approximating the Jones polynomial

    NASA Astrophysics Data System (ADS)

    Aharonov, Dorit; Arad, Itai

    2011-03-01

    A celebrated important result due to Freedman et al (2002 Commun. Math. Phys. 227 605-22) states that providing additive approximations of the Jones polynomial at the kth root of unity, for constant k=5 and k>=7, is BQP-hard. Together with the algorithmic results of Aharonov et al (2005) and Freedman et al (2002 Commun. Math. Phys. 227 587-603), this gives perhaps the most natural BQP-complete problem known today and motivates further study of the topic. In this paper, we focus on the universality proof; we extend the result of Freedman et al (2002) to ks that grow polynomially with the number of strands and crossings in the link, thus extending the BQP-hardness of Jones polynomial approximations to all values to which the AJL algorithm applies (Aharonov et al 2005), proving that for all those values, the problems are BQP-complete. As a side benefit, we derive a fairly elementary proof of the Freedman et al density result, without referring to advanced results from Lie algebra representation theory, making this important result accessible to a wider audience in the computer science research community. We make use of two general lemmas we prove, the bridge lemma and the decoupling lemma, which provide tools for establishing the density of subgroups in SU(n). Those tools seem to be of independent interest in more general contexts of proving the quantum universality. Our result also implies a completely classical statement, that the multiplicative approximations of the Jones polynomial, at exactly the same values, are #P-hard, via a recent result due to Kuperberg (2009 arXiv:0908.0512). Since the first publication of those results in their preliminary form (Aharonov and Arad 2006 arXiv:quant-ph/0605181), the methods we present here have been used in several other contexts (Aharonov and Arad 2007 arXiv:quant-ph/0702008; Peter and Stephen 2008 Quantum Inf. Comput. 8 681). The present paper is an improved and extended version of the results presented by Aharonov and Arad (2006) and includes discussions of the developments since then.

  6. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    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…

  7. Five Values of Giftedness

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  8. Drag induced radiative loss from semi-hard heavy quarks

    E-print Network

    Raktim Abir; Abhijit Majumder

    2015-09-09

    The case of gluon bremsstrahlung off a heavy quark in extended nuclear matter is revisited within the higher twist formalism. In particular, the in-medium modification of "semi-hard" heavy quarks is studied, where the momentum of the heavy quark is larger but comparable to the mass of the heavy quark ($p \\gtrsim M$). In contrast to all prior calculations, where the gluon emission spectrum is entirely controlled by the transverse momentum diffusion parameter ($\\hat q$), both for light and heavy quarks, in this work, we demonstrate that the gluon emission spectrum for a heavy quark (unlike that for flavors) is also sensitive to $\\hat e$, which so far has been used to quantify the amount of light-cone drag experienced by a parton. This mass dependent effect, due to the non-light-like momentum of a semi-hard heavy-quark, leads to an additional energy loss term for heavy-quarks, while resulting in a negligible modification of light flavor (and high energy heavy flavor) loss. This result can be used to estimate the value of this sub-leading non-perturbative jet transport parameter ($\\hat e$) from heavy flavor suppression in ultra-relativistic heavy-ion collisions.

  9. Equilibration and generalized Gibbs ensemble for hard wall boundary conditions

    NASA Astrophysics Data System (ADS)

    Goldstein, Garry; Andrei, Natan

    2015-10-01

    In this work we present an analysis of a quench for the repulsive Lieb-Liniger gas confined to a large box with hard wall boundary conditions. We study the time average of local correlation functions and show that both the quench action approach and the generalized Gibbs ensemble formalism are applicable for the long-time average of local correlation functions. We find that the time average of the system corresponds to an eigenstate of the Lieb-Liniger Hamiltonian and that this eigenstate is related to an eigenstate of a Lieb-Liniger Hamiltonian with periodic boundary conditions on an interval of twice the length and with twice as many particles (a doubled system). We further show that local operators with support far away from the boundaries of the hard wall have the same expectation values with respect to this eigenstate as corresponding operators for the doubled system. We present an example of a quench where the gas is initially confined in several moving traps and then released into a bigger container, an approximate description of the Newton's cradle experiment. We calculate the time average of various correlation functions for long times after the quench.

  10. Surface hardness of resin composites after staining and bleaching.

    PubMed

    Okte, Zeynep; Villalta, Patricia; García-Godoy, Franklin; Lu, Huan; Powers, John M

    2006-01-01

    This study investigated the effect of 3 staining solutions and 3 over-the-counter tooth-bleaching systems on the microhardness of 2 dental resin composites. Forty-five specimens of Filtek Supreme and Esthet-X were randomly assigned to 3 groups. Over a 40-day test period, the specimens in each group (n=15) were immersed in 1 of the 2 staining solutions (coffee and red wine) or distilled water as the control for 3 hours a day at room temperature. The 15 specimens in each staining group were further randomly divided into 3 subgroups, and the specimens in each subgroup (n=5) were bleached using one of the bleaching agents (Night Effects, Simply White Night and Opalescence Quick). Surface hardness was measured at 24 hours after polymerization (baseline), after staining and after bleaching. Means and standard deviations were calculated, and the data were analyzed using repeated-measures analysis of variance and Duncan's Test. The microhardness of Esthet-X was significantly higher than Filtek Supreme at baseline (p<0.01). All specimens of both materials immersed in coffee and wine revealed a significant hardness decrease compared to baseline values (p<0.05). In the control group, microhardness was increased, and this increase was statistically significant for Filtek Supreme (p<0.05). After bleaching, there was a significant decrease in mean microhardness for all groups tested (p<0.05). No significant difference was found among bleaching agents. PMID:17024953

  11. Entropy Values and Entropy Bounds Department of Mathematics

    E-print Network

    Chernov, Nikolai

    Entropy Values and Entropy Bounds N. Chernov Department of Mathematics University of Alabama rigorous mathematical results on the Kolmogorov-Sinai entropy for Lorentz gases and hard ball systems (both finite and infinite). Exact formulas and asymptotic estimates of the entropy are discussed for various

  12. Mapping QTLs for grain hardness and puroindoline content in wheat ( Triticum aestivum L.).

    PubMed

    Igrejas, G; Leroy, P; Charmet, G; Gaborit, T; Marion, D; Branlard, G

    2002-12-01

    Genes for puroindoline-a (Pin-a), puroindoline-b (Pin-b) and grain-softness proteins (GSP) have been shown to be linked to the dominant Ha locus responsible for the soft texture of the grain. Though linkage has been demonstrated of the puroindoline genes to the Ha locus, there is no clear evidence that puroindoline content is the product of the gene Ha. A segregating population of 115 recombinant inbred lines (RILs) originating from a cross between the hexaploid Synthetic wheat ( Triticum durum x Aegilops tauschii, W 7984) and the cultivar 'Opata' (M 85) was studied in two different experimental years to detect Quantitative Trait Loci (QTLs) for three traits: grain hardness (Hard), puroindoline-a (Pin-a) and puroindoline-b (Pin-b) contents. The detection of QTLs was performed using marker linear regression. Negative correlation coefficients (-0.86 and -0.80) were identified between grain hardness and puroindoline content (a and b, respectively) on data obtained in 1996. Results obtained in 1999 confirmed the negative correlation between Hard and Pin-a (-0.73); however a positive correlation coefficient was found with Pin-b content (0.41). Total phenotypic variation explained by each QTL was calculated (R2). For each of the Hard, Pin-a and Pin-b traits one major QTL was detected on the short arm of chromosome 5D, located close to the mta9 allele (puroindoline-a). For the first year (1996) the QTL in this region explained around 63% of the phenotypic variability in grain hardness, 77% in Pin-a and 45% in Pin-b contents. These values were confirmed in trials carried out in 1999 with a R2 value of 0.71, 0.72 and 0.25 for Hard, Pin-a and Pin-b, respectively. In 1996 and 1999 a second major QTL was detected for grain hardness on the long arm of the same chromosome. Present results indicate that it cannot be definitely concluded that puroindoline content represents a linear explanation for variations in grain hardness. PMID:12582867

  13. Microstructure and hardness development in a copper-nickel diffusion gradient model system

    NASA Astrophysics Data System (ADS)

    Duchstein, L. D. L.; Zhang, X.; Hansen, N.

    2015-08-01

    Cu has been electrolytically coated with Ni and subsequently deformed by rotary swaging up to a strain of e=2 to create a chemical gradient at the interface of the two elements. The extend of this chemical intermixing has been investigated through Energy Dispersive X- ray (EDX) spectroscopy in the Scanning and Transmission Electron Microscope (SEM and TEM). The depth, in which intermixing takes place, is about 1pm from the interface. Because of the uniform deformation, the structure does not get elongated but rather uniformly reduced in size. Microindentation hardness measurement shows a hardness increase from 120 to 135kp/mm2 in the Cu phase with increasing strain. After annealing at 200°C for up to 4h the hardness first decreases, but raises above the value for the highly strained sample. The experimental findings are discussed with emphasis on surface mechanical alloying as a process of both scientific and technological interest.

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

    ERIC Educational Resources Information Center

    Fibkins, William L.

    2011-01-01

    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…

  15. The material co-construction of hard science fiction and physics

    NASA Astrophysics Data System (ADS)

    Hasse, Cathrine

    2014-02-01

    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.

  16. Hard X-ray Microscopic Images of the Human Hair

    SciTech Connect

    Goo, Jawoong; Jeon, Soo Young; Oh, Tak Heon; Hong, Seung Phil; Lee, Won-Soo; Yon, Hwa Shik

    2007-01-19

    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.

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

    SciTech Connect

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

    2014-05-07

    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)

  18. Runaway electron energy measurement using hard x-ray spectroscopy in "Damavand" tokamak.

    PubMed

    Rasouli, C; Iraji, D; Farahbod, A H; Akhtari, K; Rasouli, H; Modarresi, H; Lamehi, M

    2009-01-01

    Set of experiments has been developed to study existing runaway electrons in "Damavand" tokamak plasma upon characteristics of hard x-ray emissions produced by collision of the runaway electrons with the plasma particles and limiters. As a first step, spatial distribution of hard x-ray emissions on the equatorial plane of the torus was considered. Obtained spectra of hard x-ray emissions for different alignments of shielded detector indicate isotropic emissivity in the equatorial plane. This is in agreement with wide angle cone of bremsstrahlung radiations, deduced from the mean value of energy of the runaway electrons. The mean energy was calculated from the slope of the energy spectrum of hard x-ray photons. In the second stage in order to investigate time evolution of energy of the runaway electrons, similar technique were applied to obtain hard x-ray energy in every 3 ms intervals, from the beginning to the end of plasma. The mean energy of the runaway electrons increases during the ramp up phase and reaches its maximum between 3 and 9 ms after plasma formation. Also considering the time dependence of the counted photons in each energy range shows that energetic photons are emitted during the ramp up phase of the plasma current in Damavand tokamak. PMID:19191433

  19. Stochastic Gyroresonant Acceleration for Hard Electron Spectra of Blazars: Effect of Damping of Cascading Turbulence

    NASA Astrophysics Data System (ADS)

    Kakuwa, Jun

    2016-01-01

    Stochastic acceleration of nonthermal electrons is investigated in the context of hard photon spectra of blazars. It is well known that this acceleration mechanism can produce a hard electron spectrum of m? ? {ln}{n}{{e}}(? )/? {ln}? =2 with the high-energy cutoff, called an ultrarelativistic Maxwellian-like distribution, where {n}{{e}}(? ) is an electron energy spectrum. We revisit the formation of this characteristic spectrum, considering a particular situation where the electrons are accelerated through gyroresonant interaction with magnetohydrodynamic wave turbulence driven by the turbulent cascade. By solving kinetic equations of the turbulent fields, electrons, and photons emitted via the synchrotron self-Compton (SSC) process, we demonstrate that in the non-test-particle treatment, the formation of a Maxwellian-like distribution is prevented by the damping effect on the turbulent fields due to the electron acceleration, at least unless an extreme parameter value is chosen. Instead, a softer electron spectrum with the index of m ? -1 is produced if the Kolmogorov-type cascade is assumed. The SSC spectrum that originates from the resultant softer electron spectrum is still hard, but somewhat softer and broader than the case of m = 2. This change of achievable hardness should be noted when this basic particle acceleration scenario is accurately tested with observations of hard photon spectra.

  20. Science, Values and Objectivity.

    ERIC Educational Resources Information Center

    Davson-Galle, Peter

    2002-01-01

    Attempts to ascertain whether the presence of biasing values in the practice of science is an inbuilt feature of an idealized institution, Science, and judges that those values inbuilt to Science are not a source of bias. (Author/MM)

  1. Laser ablated hard coating for microtools

    DOEpatents

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

    1998-05-05

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

  2. Laser thermographic technologies for hard copy recording

    NASA Astrophysics Data System (ADS)

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

    1995-04-01

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

  3. Laser ablated hard coating for microtools

    DOEpatents

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

    1998-05-05

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

  4. Unraveling Quantum Annealers using Classical Hardness

    E-print Network

    Victor Martin-Mayor; Itay Hen

    2015-02-09

    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.

  5. Hardness/intensity correlations among BATSE bursts

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  6. Charge heteroaggregation between hard and soft particles

    NASA Astrophysics Data System (ADS)

    Fernández-Barbero, A.; Vincent, B.

    2001-01-01

    In this paper, the heteroaggregation of opposite sign hard and soft colloidal particles has been studied by static and dynamic light scattering. The structure of the aggregates, as well as the aggregation kinetics, have been investigated. At low electrolyte concentration, where both long-range electrostatic repulsive and attractive forces are present, the aggregates were found to be more open than expected for diffusion-limited cluster aggregation (DLCA). However, the aggregate size time evolution is characteristic of diffusion-controlled processes. At high electrolyte concentration, where DLCA would be expected, very compacted clusters were found, as well as very rapid aggregation, leading to high polydispersity. These latter findings are interpreted in terms of the differences in the homoaggregation speeds for the hard and soft particles.

  7. Spin effects in hard collision processes

    SciTech Connect

    Ranft, G.; Ranft, J.

    1984-05-01

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

  8. 36 CFR 13.1308 - Harding Icefield Trail.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Kenai Fjords National Park General Provisions § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the...

  9. 36 CFR 13.1308 - Harding Icefield Trail.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Kenai Fjords National Park General Provisions § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the...

  10. 36 CFR 13.1308 - Harding Icefield Trail.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Kenai Fjords National Park General Provisions § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the...

  11. 36 CFR 13.1308 - Harding Icefield Trail.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Kenai Fjords National Park General Provisions § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the...

  12. 36 CFR 13.1308 - Harding Icefield Trail.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Kenai Fjords National Park General Provisions § 13.1308 Harding Icefield Trail. The Harding Icefield Trail from the...

  13. THERMODYAMICS Simple Equation of State for Hard-Sphere Chains

    E-print Network

    for hard-sphere chains containing up to 201 hard-sphere seg- ments. A comparison is also presented in the prediction of chemical processes and the phase behavior of fluid mix- Z .tures Sadus, 1992 . Historically

  14. ENHANCING SEED AVAILABILITY FOR THE HARD CLAM (Mercenaria mercenaria)

    E-print Network

    Florida, University of

    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

  15. 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.

  16. Experiments on asteroids using hard landers

    NASA Technical Reports Server (NTRS)

    Turkevich, A.; Economou, T.

    1978-01-01

    Hard lander missions to asteroids are examined using the Westphal penetrator study as a basis. Imagery and chemical information are considered to be the most significant science to be obtained. The latter, particularly a detailed chemical analysis performed on an uncontaminated sample, may answer questions about the relationships of asteroids to meteorites and the place of asteroids in theories of the formation of the solar system.

  17. Radiation Hardness Assurance for Space Systems

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    The space radiation environment can lead to extremely harsh operating conditions for on-board electronic box and systems. The characteristics of the radiation environment are highly dependent on the type of mission (date, duration and orbit). Radiation accelerates the aging of the electronic parts and material and can lead to a degradation of electrical performance; it can also create transient phenomena on parts. Such damage at the part level can induce damage or functional failure at electronic box, subsystem, and system levels. A rigorous methodology is needed to ensure that the radiation environment does not compromise the functionality and performance of the electronics during the system life. This methodology is called hardness assurance. It consists of those activities undertaken to ensure that the electronic piece parts placed in the space system perform to their design specifications after exposure to the space environment. It deals with system requirements, environmental definitions, part selection, part testing, shielding and radiation tolerant design. All these elements should play together in order to produce a system tolerant to.the radiation environment. An overview of the different steps of a space system hardness assurance program is given in section 2. In order to define the mission radiation specifications and compare these requirements to radiation test data, a detailed knowledge of the space environment and the corresponding electronic device failure mechanisms is required. The presentation by J. Mazur deals with the Earth space radiation environment as well as the internal environment of a spacecraft. The presentation by J. Schwank deals with ionization effects, and the presentation by T. Weatherford deals with Single particle Event Phenomena (SEP) in semiconductor devices and microcircuits. These three presentations provide more detailed background to complement the sections 3 and 4. Part selection and categorization are discussed in section 5. Section 6 presents the organization of the hardness assurance within a project. Section 7 discusses emerging radiation hardness assurance issues.

  18. Dynamic Hardness Tester and Cure Meter

    NASA Technical Reports Server (NTRS)

    Madigosky, Walter M.; Fiorito, Ralph B.

    1993-01-01

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

  19. Nanotwinned diamond with unprecedented hardness and stability

    NASA Astrophysics Data System (ADS)

    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

    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.

  20. Circle Packing for Origami Design Is Hard

    E-print Network

    Demaine, Erik D; Lang, Robert J

    2010-01-01

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

  1. Nanotwinned diamond with unprecedented hardness and stability.

    PubMed

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

    2014-06-12

    Although diamond is the hardest material for cutting tools, poor thermal stability has limited its applications, especially at high temperatures. Simultaneous improvement of the hardness and thermal stability of diamond has long been desirable. According to the Hall-Petch effect, the hardness of diamond can be enhanced by nanostructuring (by means of nanograined and nanotwinned microstructures), as shown in previous studies. However, for well-sintered nanograined diamonds, the grain sizes are technically limited to 10-30?nm (ref. 3), with degraded thermal stability compared with that of natural diamond. Recent success in synthesizing nanotwinned cubic boron nitride (nt-cBN) with a twin thickness down to ?3.8?nm makes it feasible to simultaneously achieve smaller nanosize, ultrahardness and superior thermal stability. At present, nanotwinned diamond (nt-diamond) has not been fabricated successfully through direct conversions of various carbon precursors (such as graphite, amorphous carbon, glassy carbon and C60). Here we report the direct synthesis of nt-diamond with an average twin thickness of ?5?nm, using a precursor of onion carbon nanoparticles at high pressure and high temperature, and the observation of a new monoclinic crystalline form of diamond coexisting with nt-diamond. The pure synthetic bulk nt-diamond material shows unprecedented hardness and thermal stability, with Vickers hardness up to ?200?GPa and an in-air oxidization temperature more than 200?°C higher than that of natural diamond. The creation of nanotwinned microstructures offers a general pathway for manufacturing new advanced carbon-based materials with exceptional thermal stability and mechanical properties. PMID:24919919

  2. Rad-Hard/HI-REL FPGA

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  3. Hierarchical Classification of Values

    ERIC Educational Resources Information Center

    Ergen, Gürkan

    2015-01-01

    Values are of utmost importance for the creation, development and sustainability of a life worthy of human dignity. However, because even superficial views of values are regarded as values themselves, they have become relative and become degenerated; therefore, they have lost the properties--potentials and powers--essential to human dignity. This…

  4. 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...

  5. Values Drive the Plan

    ERIC Educational Resources Information Center

    Cook, Les P.

    2010-01-01

    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…

  6. Surgical lasers and hard dental tissue.

    PubMed

    Parker, S

    2007-04-28

    The cutting of dental hard tissue during restorative procedures presents considerable demands on the ability to selectively remove diseased carious tissue, obtain outline and retention form and maintain the integrity of supporting tooth tissue without structural weakening. In addition, the requirement to preserve healthy tissue and prevent further breakdown of the restoration places the choice of instrumentation and clinical technique as prime factors for the dental surgeon. The quest for an alternative treatment modality to the conventional dental turbine has been, essentially, patient-driven and has led to the development of various mechanical and chemical devices. The review of the literature has endorsed the beneficial effects of current laser machines. However utopian, there is additional evidence to support the development of ultra-short (nano- and femto-second) pulsed lasers that are stable in use and commercially viable, to deliver more efficient hard tissue ablation with less risk of collateral thermal damage. This paper explores the interaction of laser energy with dental hard tissues and bone and the integration of current laser wavelengths into restorative and surgical dentistry. PMID:17471204

  7. Characterization of Radiation Hard Silicon Materials

    SciTech Connect

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

    2009-02-24

    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.

  8. Magnetic hyperthermia with hard-magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  9. Solving the hard problem of Bertrand's paradox

    SciTech Connect

    Aerts, Diederik; Sassoli de Bianchi, Massimiliano

    2014-08-15

    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.

  10. February 24, 2009 Radiation-Hardness of VCSEL/PIN

    E-print Network

    Gan, K. K.

    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

  11. Addendum to: Uniform Elongation and the Stress-Strain Flow Curve of Steels Calculated from Hardness Using Empirical Correlations

    NASA Astrophysics Data System (ADS)

    Pavlina, Erik J.; Van Tyne, Chester J.

    2015-09-01

    The original study by Pavlina and Van Tyne developed correlations of hardness and strength (yield and ultimate tensile strength) (Pavlina and Van Tyne in J Mater Eng Perform 17:888-893, 2008). As an extension to this original work, a later paper developed an empirical relationship between the hardness and uniform elongation of non-austenitic hypoeutectoid steels (Pavlina and Van Tyne in J Mater Eng Perform 23:2247-2254, 2014). The empirical hardness-elongation relationship was combined with the correlations in the original study to show how a single hardness test could predict a reasonable stress-strain flow curve for a steel. The current study provides tables of parameter values for four different hardening models, based on the hardness correlations that were developed in the two previous studies. The models are the two-parameter Holloman model and the three-parameter Ludwig, Swift, and Voce models. Although they are empirical, these parameters allow the flow behavior of steels to be reasonably well characterized, based on a single hardness value. These tables should only be used when limited material is available, or when insufficient data are available for the specific grade of steel needing characterization.

  12. Addendum to: Uniform Elongation and the Stress-Strain Flow Curve of Steels Calculated from Hardness Using Empirical Correlations

    NASA Astrophysics Data System (ADS)

    Pavlina, Erik J.; Van Tyne, Chester J.

    2015-11-01

    The original study by Pavlina and Van Tyne developed correlations of hardness and strength (yield and ultimate tensile strength) (Pavlina and Van Tyne in J Mater Eng Perform 17:888-893, 2008). As an extension to this original work, a later paper developed an empirical relationship between the hardness and uniform elongation of non-austenitic hypoeutectoid steels (Pavlina and Van Tyne in J Mater Eng Perform 23:2247-2254, 2014). The empirical hardness-elongation relationship was combined with the correlations in the original study to show how a single hardness test could predict a reasonable stress-strain flow curve for a steel. The current study provides tables of parameter values for four different hardening models, based on the hardness correlations that were developed in the two previous studies. The models are the two-parameter Holloman model and the three-parameter Ludwig, Swift, and Voce models. Although they are empirical, these parameters allow the flow behavior of steels to be reasonably well characterized, based on a single hardness value. These tables should only be used when limited material is available, or when insufficient data are available for the specific grade of steel needing characterization.

  13. How Hard Can It Be? Margaret H. Wright

    E-print Network

    Ciocan-Fontanine, Ionut

    How Hard Can It Be? Margaret H. Wright Computer Science Department Courant Institute,000 Google hits for "How hard can it be" A typical example: Thelma: I don't know how to fish. Louise: Well, neither do I, but Darryl does--how hard can it be? From the film Thelma and Louise, 1992. #12;How

  14. CONTINUOUS HARD-TO-INVERT FUNCTIONS AND BIOMETRIC AUTHENTICATION

    E-print Network

    Grigoriev, Dima

    CONTINUOUS HARD-TO-INVERT FUNCTIONS AND BIOMETRIC AUTHENTICATION DIMA GRIGORIEV AND SERGEY several candidates for contin- uous hard-to-invert functions. To formulate these candidates, we introduce. In this work, we propose several candidates for continuous hard- to-invert functions, as introduced in [16

  15. WATER REQUIREMENTSWATER REQUIREMENTSWATER REQUIREMENTSWATER REQUIREMENTS of Hard Red Spring Wheat

    E-print Network

    O'Laughlin, Jay

    WATER REQUIREMENTSWATER REQUIREMENTSWATER REQUIREMENTSWATER REQUIREMENTS of Hard Red Spring Wheat C. Hopkins #12;Estimating Water Requirements of Hard Red Spring Wheat for Final Irrigations 2 Introductiond water use Producers of hard red spring wheat know that inadequate water reduces yield and quality

  16. Design of Hard Water Stable Emulsifier Systems for Petroleum-

    E-print Network

    Clarens, Andres

    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

  17. Hard Drive & Magnetic Media Destruction Request Form Name: Department

    E-print Network

    Mountziaris, T. J.

    Page 1 Hard Drive & Magnetic Media Destruction Request Form Name: Department: Phone: Building hard drive, tape, floppy, etc. or other identifying information 1 2 3 4 5 Please return the media to me department with data intact under any circumstance. #12;Page 2 Hard Drive & Magnetic Media Destruction

  18. Hardness Amplification within NP against Deterministic Algorithms Parikshit Gopalan

    E-print Network

    Guruswami, Venkatesan

    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

  19. Texts in Computational Complexity: Ampli cation of Hardness

    E-print Network

    Goldreich, Oded

    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

  20. The Cryptographic Hardness of Random Local Functions Benny Applebaum

    E-print Network

    International Association for Cryptologic Research (IACR)

    The Cryptographic Hardness of Random Local Functions (Survey) Benny Applebaum Abstract Constant-size subset of the input bits. In this work, we will study the cryptographic hardness of random local functions. In par- ticular, we will survey known attacks and hardness results, discuss different flavors

  1. Study of hot hardness characteristics of tool steels

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  2. Hardness of the Covering Radius Problem on Lattices Ishay Haviv

    E-print Network

    Regev, Oded

    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

  3. A Bayesian Approach to Hardness Ratios for non-Bayesians

    E-print Network

    Davis, John E.

    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

  4. Hardness of SIS and LWE with Small Parameters Daniele Micciancio

    E-print Network

    International Association for Cryptologic Research (IACR)

    Hardness of SIS and LWE with Small Parameters Daniele Micciancio Chris Peikert February 13, 2013 for countless applications in lattice-based cryptography, and are provably as hard as approximate lattice small their parameters can be made, while preserving their hardness. We prove two main results on SIS

  5. MATERIALS CHARACTERISATION Material properties such as strength, toughness or hardness

    E-print Network

    MATERIALS CHARACTERISATION Material properties such as strength, toughness or hardness are usually factors. This paper presents an experimental evidence that hardness of rolled martensitic steel can for the characterisation of material properties; parameters, such as elastic modulus, material microstructure, hardness etc

  6. Noncontact Human Force Capturing based on Surface Hardness Measurement

    E-print Network

    Shinoda, Hiroyuki

    Noncontact Human Force Capturing based on Surface Hardness Measurement Masahiro Fujiwara method based on skin surface hardness measurement. The measurement system is composed of an airborne ultrasound phased array and a laser displacement sensor. The surface hardness distribution of a human hand

  7. Uniform Hardness Amplification in NP via Monotone Codes

    E-print Network

    Kabanets, Valentine

    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

  8. Counterexamples to Hardness Amplification Beyond Negligible Yevgeniy Dodis

    E-print Network

    International Association for Cryptologic Research (IACR)

    Counterexamples to Hardness Amplification Beyond Negligible Yevgeniy Dodis Abhishek Jain Tal Moran Daniel Wichs§ January 19, 2012 Abstract If we have a problem that is mildly hard, can we create a problem that is significantly harder? A natural approach to hardness amplification is the "direct product"; instead of asking

  9. Hard and soft locking Andrew Knyazev, CU-Denver

    E-print Network

    Knyazev, Andrew

    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

  10. Jamming in hard sphere and disk packings Aleksandar Donev

    E-print Network

    Torquato, Salvatore

    Jamming in hard sphere and disk packings Aleksandar Donev Program in Applied and Computational, living cells, glasses, and random media. The nature of ``jammed'' hard-particle packings is a current to assess whether a hard-sphere packing is locally, collectively, or strictly jammed, as defined by Torquato

  11. HARDNESS AMPLIFICATION VIA SPACE-EFFICIENT DIRECT PRODUCTS

    E-print Network

    Guruswami, Venkatesan

    HARDNESS AMPLIFICATION VIA SPACE-EFFICIENT DIRECT PRODUCTS Venkatesan Guruswami and Valentine this construction, we get a deterministic linear-space "worst-case to con- stant average-case" hardness- panders (Dinur 2006). Keywords. Direct products, hardness amplification, error-correcting codes, expanders

  12. Fault-Tolerant, Radiation-Hard DSP

    NASA Technical Reports Server (NTRS)

    Czajkowski, David

    2011-01-01

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

  13. Calculation of the interfacial free energy of a binary hard-sphere fluid at a planar hard wall

    E-print Network

    Kern, Jesse L.; Laird, Brian Bostian

    2014-01-08

    Using molecular-dynamics simulation and Gibbs-Cahn Integration, we calculate the interfacial free energy ? of a binary hard-sphere fluid mixture at a structureless, planar hard wall. The calculation is performed as a function of packing fraction...

  14. 4-channel rad-hard delay generation ASIC with 1ns timing resolution for LHC

    SciTech Connect

    Toifl, T.; Moreira, P.; Marchioro, A.; Vari, R.

    1999-06-01

    An ASIC was developed to precisely delay digital signals within the range of 0--24ns in steps of 1ns. To obtain well defined delay values independent of variations in process, supply voltage and temperature, four independent delay channels are controlled by a common control voltage derived from a delay-locked loop (DLL), which is synchronized to an external 40 MHz clock signal. The delay values of the four signal channels and the clock channel can be individually programmed via an I{sup 2}C interface. Due to an automatic reset logic the chip does not need an external reset signal. A first version of the chip was developed in a non-rad-hard 0.8 {micro}m technology and the successful prototype was then transferred to a radiation hard process (DMILL). Measurement results for both chip variants will be presented.

  15. The problem with value.

    PubMed

    O'Doherty, John P

    2014-06-01

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

  16. The problem with value

    PubMed Central

    O’Doherty, John P.

    2015-01-01

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

  17. Quantity and quantity value

    NASA Astrophysics Data System (ADS)

    Mari, Luca; Giordani, Alessandro

    2012-12-01

    The concept system around ‘quantity’ and ‘quantity value’ is fundamental for measurement science, but some very basic issues are still open on such concepts and their relation. This paper argues that quantity values are in fact individual quantities, and that a complementarity exists between measurands and quantity values. This proposal is grounded on the analysis of three basic ‘equality’ relations: (i) between quantities, (ii) between quantity values and (iii) between quantities and quantity values. A consistent characterization of such concepts is obtained, which is then generalized to ‘property’ and ‘property value’. This analysis also throws some light on the elusive concept of magnitude. A preliminary version of this paper was presented and discussed at the Joint International IMEKO TC1, TC7 & TC13 Symposium, 31 August to 2 September 2011, Jena, Germany.

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

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    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.

  19. CO2 laser milling of hard tissue

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

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

  20. Nonvolatile Rad-Hard Holographic Memory

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  1. Hard gamma ray emission from blazars

    NASA Technical Reports Server (NTRS)

    Marscher, Alan P.; Bloom, Steven D.

    1992-01-01

    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.

  2. Hard Exclusive ?^0-Meson Production at COMPASS

    E-print Network

    H. Wollny for the COMPASS collaboration

    2012-05-30

    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.

  3. Hard pion bremsstrahlung in the Coulomb region

    E-print Network

    Göran Fäldt; Ulla Tengblad

    2007-08-02

    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.

  4. The bounce hardness index of gravitational waves

    E-print Network

    Fumihiko Ishiyama; Ryutaro Takahashi

    2010-12-06

    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.

  5. Classic Nintendo Games are (NP-)Hard

    E-print Network

    Aloupis, Greg; Guo, Alan

    2012-01-01

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

  6. Organic hard masks utilizing fullerene derivatives

    NASA Astrophysics Data System (ADS)

    Frommhold, Andreas; Brown, Alan G.; Palmer, Richard E.; Lada, Tom; Robinson, Alex P.

    2015-03-01

    We have developed a series of fullerene containing materials for use as organic hard masks. Films with a thickness of up to 250 nm were deposited via spin coating. After a crosslinking bake the films exhibit good thermal stability - in the best case a mass loss of less than 3% at 400 °C is seen. Etch resistance of the different formulations are presented and hig-hresolution patterning is demonstrated. During the transfer into silicon no adverse "wiggling" is observed at high resolution. We attribute this to the low levels of aliphatic hydrogen present in the materials.

  7. Evolutionary algorithm based structure search for hard ruthenium carbides

    NASA Astrophysics Data System (ADS)

    Harikrishnan, G.; Ajith, K. M.; Chandra, Sharat; Valsakumar, M. C.

    2015-12-01

    An exhaustive structure search employing evolutionary algorithm and density functional theory has been carried out for ruthenium carbides, for the three stoichiometries Ru1C1, Ru2C1 and Ru3C1, yielding five lowest energy structures. These include the structures from the two reported syntheses of ruthenium carbides. Their emergence in the present structure search in stoichiometries, unlike the previously reported ones, is plausible in the light of the high temperature required for their synthesis. The mechanical stability and ductile character of all these systems are established by their elastic constants, and the dynamical stability of three of them by the phonon data. Rhombohedral structure ?ft(R\\bar{3}m\\right) is found to be energetically the most stable one in Ru1C1 stoichiometry and hexagonal structure ?ft( P\\bar{6}m2\\right) , the most stable in Ru3C1 stoichiometry. RuC–Zinc blende system is a semiconductor with a band gap of 0.618?eV while the other two stable systems are metallic. Employing a semi-empirical model based on the bond strength, the hardness of RuC–Zinc blende is found to be a significantly large value of ~37 GPa while a fairly large value of ~21GPa is obtained for the RuC–Rhombohedral system. The positive formation energies of these systems show that high temperature and possibly high pressure are necessary for their synthesis.

  8. The GINGA hard X-ray spectrum of AM Herculis

    NASA Astrophysics Data System (ADS)

    Beardmore, A. P.; Done, C.; Osborne, J. P.; Ishida, M.

    1995-02-01

    We present an analysis of the phase-resolved 2-30 keV X-ray spectrum of the prototype magnetic cataclysmic variable AM Herculis obtained with the Ginga satellite. The bremsstrahlung flux varies by more than a factor of 7 as a function of orbital phase, demonstrating that the X-ray orbital intensity variation is due to partial occultation which varies with the viewing angle. The spectrum is hardest when the source is brightest in its orbital cycle, and the phase-resolved spectra are not well fitted by simple models with a narrow line plus continuum. The derived high and variable bremsstrahlung temperature cannot account for the observed line emission, and the residuals to these fits indicate complex behaviour at high and low energies. The latter is shown to be consistent with a complex absorber, and both partial covering and partial ionization give a good description of the soft spectrum. The residuals above 6 keV are well modelled by reflection from the white dwarf surface, where the amount of reflection varies with phase as predicted by the changing inclination of the white dwarf surface. The inclusion of this hard and variable spectral component gives a temperature for the post-shock region of ~13.5 keV, which is constant with phase. This value is considerably lower than previous estimates, allowing the high equivalent width of the iron line to be explained as a combination of a thermal line blend at 6.8 keV and a 6.4-keV fluorescent component. This new low bremsstrahlung temperature suggests that the hard X-ray luminosities of AM Her systems may have been overestimated, exacerbating the soft X-ray problem. The detailed modelling of the complex low-energy spectrum affects the derived ionization state of the reflector: with partial covering of cold material the reflection spectrum is significantly ionized, but with an ionized absorber the reflecting surface is cold.

  9. Effect of Annealing Temperature on Hardness and Wear Resistance of Electroless Ni-B-Mo Coatings

    NASA Astrophysics Data System (ADS)

    Serin, Ihsan Gökhan; Göksenli, Ali

    2015-06-01

    Formation of nickel-boron-molybdenum (Ni-B-Mo) coating on steel by electroless plating and evaluation of their morphology, hardness and tribological properties post heat treatment at different temperatures for 1 h is investigated. The 25 ?m thick coating is uniform and adhesion between the substrate and coating is good. Ni-B-Mo coating was amorphous-like structure in their as-plated condition and by 400°C heat-treated coating, nickel fully crystallized and nickel borides and molybdenum carbide were formed. All coatings exhibited higher hardness than the substrate steel. Hardness values of all coatings up to 400°C did not change distinctively but decreased partly beyond 400°C. Friction coefficient reached lowest value post heat treatment at 300°C but later increased with increasing tempering temperature. Wear resistance was lowest in as-plated coating; however it reached the highest value at 300°C. Worn surface of the coatings showed the abrasive wear as the dominant wear mechanism. An additional adhesive wear mechanism was detected in coating tempered at 550°C. Moreover, our results confirmed that the molybdenum addition improved the thermal stability of the resulting coating. Therefore, Ni-B-Mo coating has potential for application in precision mould, optical parts mould or bipolar plates, where thermal stability is essential.

  10. Adopting professional values.

    PubMed

    Jones, Jane Redfern

    2014-12-01

    Nurses often care for vulnerable people and those who may have a lifestyle that society considers unconventional or unacceptable. To meet the needs of our patients, we should be aware of our own values, beliefs and attitudes, and not impose them on patients. We need to adopt the professional values of our workplace. PMID:25424117

  11. Cognitive and Social Values.

    ERIC Educational Resources Information Center

    Machamer, Peter; Douglas, Heather

    1999-01-01

    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…

  12. 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.

  13. How I Taught Values

    ERIC Educational Resources Information Center

    Pratt, Annis

    2005-01-01

    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…

  14. High coking value pitch

    SciTech Connect

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

    2014-06-10

    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.

  15. Valuing Youth. Leader's Notebook.

    ERIC Educational Resources Information Center

    Glashagel, Jerry; And Others

    This leader's notebook is an attempt to present value education tools for persons working with elementary age children in various YMCA settings. These tools are value education strategies designed to stimulate discussion by the children and to help create a learning environment. The strategies are presented in two ways. First, a series of basic…

  16. Art's Educational Value

    ERIC Educational Resources Information Center

    Richmond, Stuart

    2009-01-01

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

  17. Weak Value Theory

    SciTech Connect

    Shikano, Yutaka

    2011-03-28

    I show that the weak value theory is useful from the viewpoints of the experimentally verifiability, consistency, capacity for explanation as to many quantum paradoxes, and practical advantages. As an example, the initial state in the Hardy paradox can be experimentally verified using the weak value via the weak measurement.

  18. External Memory Value Iteration

    E-print Network

    Morik, Katharina

    , applicable actions, tran- sition functions, and cost of applying actions on states, which is able to modelExternal Memory Value Iteration Stefan Edelkamp Shahid Jabbar Blai Bonet Forschungsbericht Nr. 813 April 2007 #12;External Memory Value Iteration Stefan Edelkamp Computer Science Department University

  19. Work Values across Generations

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

  20. Understanding Place Value

    ERIC Educational Resources Information Center

    Cooper, Linda L.; Tomayko, Ming C.

    2011-01-01

    Developing an understanding of place value and the base-ten number system is considered a fundamental goal of the early primary grades. For years, teachers have anecdotally reported that students struggle with place-value concepts. Among the common errors cited are misreading such numbers as 26 and 62 by seeing them as identical in meaning,…

  1. Rosenak "Teaching Jewish Values"

    ERIC Educational Resources Information Center

    Resnick, David

    2014-01-01

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

  2. Ultrasonically bonded value assembly

    NASA Technical Reports Server (NTRS)

    Salvinski, R. J. (inventor)

    1975-01-01

    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.

  3. Shock Compression Properties of Hard Materials

    NASA Astrophysics Data System (ADS)

    Mashimo, T.

    2007-12-01

    Through the measurement of Hugoniot parameters, we can get useful information about high-pressure phase transitions, equations of state (EOS), etc. of solids, without pressure calibration. We have performed the Hugoniot measurement experiments on various kinds of hard materials including chalcogenides, oxides, nitrides, and borides by using a high time-resolution streak photographic system (inclined-mirror method). It was found that almost all brittle materials behave as an elasto-isotropic solid which loses shear strength much above the HEL, unlike metals (elasto-plastic solid), except TiB2. The phase transitions have been observed for ZnS, ZnSe, TiO2, ZrO2, Gd3Ga5O12, AlN, B4C, etc. Some oxide materials showed virtually incompressible EOS's in the high-pressure phase region. Here, the Hugoniot compression data are reviewed, and the yield property and phase transitions of these hard materials are discussed, as well as the EOS of the high-pressure phase.

  4. Hard Real-Time: C++ Versus RTSJ

    NASA Technical Reports Server (NTRS)

    Dvorak, Daniel L.; Reinholtz, William K.

    2004-01-01

    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.

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

    ERIC Educational Resources Information Center

    Song, H. Rosi

    2009-01-01

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

  6. Fractions, Decimals, Ratios, & Percents: Hard To Teach and Hard To Learn? Mathematics Teaching Cases.

    ERIC Educational Resources Information Center

    Barnett, Carne, Ed.; And Others

    This book presents teacher-written cases relating stories, insights, and experiences about the teaching of fractions, decimals, ratios, and percents. The cases were written to stimulate colleagues to examine their own practice, to think hard about the mathematics they teach and would like to teach, and to initiate inquiries and discussions that…

  7. Phase transition induced by a shock wave in hard-sphere and hard-disk systems.

    PubMed

    Zhao, Nanrong; Sugiyama, Masaru; Ruggeri, Tommaso

    2008-08-01

    Dynamic phase transition induced by a shock wave in hard-sphere and hard-disk systems is studied on the basis of the system of Euler equations with caloric and thermal equations of state. First, Rankine-Hugoniot conditions are analyzed. The quantitative classification of Hugoniot types in terms of the thermodynamic quantities of the unperturbed state (the state before a shock wave) and the shock strength is made. Especially Hugoniot in typical two possible cases (P-1 and P-2) of the phase transition is analyzed in detail. In the case P-1 the phase transition occurs between a metastable liquid state and a stable solid state, and in the case P-2 the phase transition occurs through coexistence states, when the shock strength changes. Second, the admissibility of the two cases is discussed from a viewpoint of the recent mathematical theory of shock waves, and a rule with the use of the maximum entropy production rate is proposed as the rule for selecting the most probable one among the possible cases, that is, the most suitable constitutive equation that predicts the most probable shock wave. According to the rule, the constitutive equation in the case P-2 is the most promising one in the dynamic phase transition. It is emphasized that hard-sphere and hard-disk systems are suitable reference systems for studying shock wave phenomena including the shock-induced phase transition in more realistic condensed matters. PMID:18698913

  8. Nanoindentation hardness of soft films on hard substrates: Effects of the substrate

    SciTech Connect

    Tsui, T.Y.; Ross, C.A.; Pharr, G.M.

    1997-06-01

    The ability to accurately measure the mechanical properties of thin metallic films is important in the semiconductor industry as it relates to device reliability issues. One popular technique for measuring thin film mechanical properties is nanoindentation. This technique has the advantage of being able to measure properties such as hardness and elastic modulus without removing a film from its substrate. However, according to a widely-held rule of thumb, intrinsic film properties can be measured in a manner which is not influenced by the substrate only if the indentation depth is kept to less than 10% of the film thickness, which is often not practical. In this work, a method for making substrate independent hardness measurements of soft metallic films on hard substrates is proposed. The primary issue to be addressed is the substrate-induced enhancement of indentation pile-up and the ways in which this pile-up influences the contact area determined from analyses of nanoindentation load- displacement data. Based on experimental observations of soft aluminum films on silicon, glass, and sapphire substrates, a simple empirical relationship is derived which relates the amount of pile-up to the contact depth. From this relationship, a simple method is developed which allows the intrinsic hardness of the film to be measured by nanoindentation methods even when the indenter penetrates through the film into the substrate.

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

    E-print Network

    Qingwen Wu; Minfeng Gu

    2008-12-17

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

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

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

    2009-12-01

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

  12. A Group Orientation Approach for Facilitating the Work of Adjustment of the Hard-Core Unemployed. Final Report.

    ERIC Educational Resources Information Center

    Rosen, Hjalmar; Teahan, John E.

    The major objective of this project was to achieve a lasting integration of Negro hard-core unemployed men in an ongoing corporate work force. It was intended to develop values necessary for successful employment, particularly with regard to regularity of attendance, punctuality, conformity to work rules and regulations, and motivation to accept…

  13. Relationship Between Crystalline Structure and Hardness of Ti-Si-N-O Coatings Fabricated by dc Sputtering

    NASA Astrophysics Data System (ADS)

    García-González, Leandro; Hernández-Torres, Julián; Mendoza-Barrera, Claudia; Meléndez-Lira, Miguel; García-Ramírez, Pedro J.; Martínez-Castillo, Jaime; Sauceda, Ángel; Herrera-May, Agustin L.; Muñoz Saldaña, Juan; Espinoza-Beltrán, Francisco J.

    2008-08-01

    Ti-Si-N-O coatings were deposited on AISI D2 tool steel and silicon substrates by dc reactive magnetron co-sputtering using a target of Ti-Si with a constant area ratio of 0.2. The substrate temperature was 400 °C and reactive atmosphere of nitrogen and argon. For all samples, argon flow was maintained constant at 25 sccm, while the flow of the nitrogen was varied to analyze the structural changes related to chemical composition and resistivity. According to results obtained by x-ray diffraction and stoichiometry calculations by x-ray energy dispersive spectroscopy the Ti-Si-N-O coatings contain two solid solutions. The higher crystalline part corresponds to titanium oxynitrure. Hardness tests on the coatings were carried out using the indentation work model and the hardness value was determined. Finally, the values of hardness were corroborated by nanoindentation test, and values of Young’s modulus and elastic recovery were discussed. We concluded that F2TSN sample ( F Ar = 25 sccm, F N = 5 sccm, P = 200 W, and P W = 8.9 × 10-3 mbar) presented the greatest hardness and the lowest resistivity values, due to its preferential crystalline orientation.

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

    SciTech Connect

    Yamada, S.; Makishima, K.; Negoro, H.; Torii, S.; Noda, H.; Mineshige, S.

    2013-04-20

    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.

  15. Adsorption of hard spheres: structure and effective density according to the potential distribution theorem

    E-print Network

    L. L. Lee; G. Pellicane

    2012-02-20

    We propose a new type of effective densities via the potential distribution theorem. These densities are for the sake of enabling the mapping of the free energy of a uniform fluid onto that of a nonuniform fluid. The potential distribution theorem gives the work required to insert a test particle into the bath molecules under the action of the external (wall) potential. This insertion work W_ins can be obtained from Monte Carlo (MC) simulation (e.g. from Widom's test particle technique) or from an analytical theory. The pseudo-densities are constructed thusly so that when their values are substituted into a uniform-fluid equation of state (e.g. the Carnahan-Starling equation for the hard-sphere chemical potentials), the MC nonuniform insertion work is reproduced. We characterize the pseudo-density behavior for the hard spheres/hard wall system at moderate to high densities (from \\rho^*= 0.5745 to 0.9135). We adopt the MC data of Groot et al. for this purpose. The pseudo-densities show oscillatory behavior out of phase (opposite) to that of the singlet densities. We also construct a new closure-based density functional theory (the star-function based density functional theory) that can give accurate description of the MC density profiles and insertion works. A viable theory is established for several cases in hard sphere adsorption.

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

    PubMed

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

    2014-01-01

    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

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

    PubMed Central

    Davis, Claire

    2014-01-01

    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

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

    SciTech Connect

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

    2007-01-24

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

  19. Value of Information References

    DOE Data Explorer

    Morency, Christina

    2014-12-12

    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.

  20. Nutritive value of fall-grown cereal-grain forages over time.

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Resistivitet-och IP-mtningar vid sp Hard

    E-print Network

    1 Resistivitet- och IP- mätningar vid �spö Hard Rock Laboratory Erik Fennvik Examensarbeten i universitet 2015 #12;2 #12;3 Resistivitet- och IP-mätningar vid �spö Hard Rock Laboratory Kandidatarbete Erik-mätningar vid �spö Hard Rock Laboratory ERIK FENNVIK Fennvik, E., 2015: Resistivitet­ och IP-mätningar vid �spö

  3. The statistical mechanics of inhomogeneous hard rod mixtures

    SciTech Connect

    Vanderlick, T.K.; Davis, H.T. ); Percus, J.K. )

    1989-12-01

    The exact statistical mechanical solution to the problem of an equilibrium inhomogeneous classical one-dimensional mixture of hard rods is presented. From the solution, thermodynamic properties, density profiles, and correlation functions of hard rod fluids confined to small regions (micropores) can be calculated. The theory is applied to investigate microstructure, pore pressures, and pore adsorption selectivity of micropores in equilibrium with binary hard rod mixtures. A prescription is suggested for generalizing the one-dimensional results to higher dimensions.

  4. Radiation Hard AlGaN Detectors and Imager

    SciTech Connect

    2012-05-01

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

  5. Shock compression synthesis of hard materials

    SciTech Connect

    Willson, C.G.

    1999-03-01

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

  6. Ordering and Dynamics of Vibrated Hard Squares

    E-print Network

    Lee Walsh; Narayanan Menon

    2015-10-02

    We study an experimental system of hard granular squares in two dimensions, energized by vibration. The interplay of order in the orientations and positions of anisotropic particles allows for a rich set of phases. We measure the structure and dynamics of steady states as a function of particle density. This allows us to identify a progression of phases in which a low density isotropic fluid gives way to a phase with tetratic orientational order, short-range translational correlations, and slowed rotational dynamics. In this range of density we also observe a coupling between the orientational order and bond-orientational order. At higher densities, the particles freeze into a translationally and orientationally ordered square crystalline phase in which translational diffusion is suppressed.

  7. Radiation Hardness Assurance (RHA) for Space Systems

    NASA Technical Reports Server (NTRS)

    Poivey, Christian; Buchner, Stephen

    2007-01-01

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

  8. Nanomechanics of hard films on compliant substrates.

    SciTech Connect

    Reedy, Earl David, Jr.; Emerson, John Allen; Bahr, David F.; Moody, Neville Reid; Zhou, Xiao Wang; Hales, Lucas; Adams, David Price; Yeager,John; Nyugen, Thao D.; Corona, Edmundo; Kennedy, Marian S.; Cordill, Megan J.

    2009-09-01

    Development of flexible thin film systems for biomedical, homeland security and environmental sensing applications has increased dramatically in recent years [1,2,3,4]. These systems typically combine traditional semiconductor technology with new flexible substrates, allowing for both the high electron mobility of semiconductors and the flexibility of polymers. The devices have the ability to be easily integrated into components and show promise for advanced design concepts, ranging from innovative microelectronics to MEMS and NEMS devices. These devices often contain layers of thin polymer, ceramic and metallic films where differing properties can lead to large residual stresses [5]. As long as the films remain substrate-bonded, they may deform far beyond their freestanding counterpart. Once debonded, substrate constraint disappears leading to film failure where compressive stresses can lead to wrinkling, delamination, and buckling [6,7,8] while tensile stresses can lead to film fracture and decohesion [9,10,11]. In all cases, performance depends on film adhesion. Experimentally it is difficult to measure adhesion. It is often studied using tape [12], pull off [13,14,15], and peel tests [16,17]. More recent techniques for measuring adhesion include scratch testing [18,19,20,21], four point bending [22,23,24], indentation [25,26,27], spontaneous blisters [28,29] and stressed overlayers [7,26,30,31,32,33]. Nevertheless, sample design and test techniques must be tailored for each system. There is a large body of elastic thin film fracture and elastic contact mechanics solutions for elastic films on rigid substrates in the published literature [5,7,34,35,36]. More recent work has extended these solutions to films on compliant substrates and show that increasing compliance markedly changes fracture energies compared with rigid elastic solution results [37,38]. However, the introduction of inelastic substrate response significantly complicates the problem [10,39,40]. As a result, our understanding of the critical relationship between adhesion, properties, and fracture for hard films on compliant substrates is limited. To address this issue, we integrated nanomechanical testing and mechanics-based modeling in a program to define the critical relationship between deformation and fracture of nanoscale films on compliant substrates. The approach involved designing model film systems and employing nano-scale experimental characterization techniques to isolate effects of compliance, viscoelasticity, and plasticity on deformation and fracture of thin hard films on substrates that spanned more than two orders of compliance magnitude exhibit different interface structures, have different adhesion strengths, and function differently under stress. The results of this work are described in six chapters. Chapter 1 provides the motivation for this work. Chapter 2 presents experimental results covering film system design, sample preparation, indentation response, and fracture including discussion on the effects of substrate compliance on fracture energies and buckle formation from existing models. Chapter 3 describes the use of analytical and finite element simulations to define the role of substrate compliance and film geometry on the indentation response of thin hard films on compliant substrates. Chapter 4 describes the development and application of cohesive zone model based finite element simulations to determine how substrate compliance affects debond growth. Chapter 5 describes the use of molecular dynamics simulations to define the effects of substrate compliance on interfacial fracture of thin hard tungsten films on silicon substrates. Chapter 6 describes the Workshops sponsored through this program to advance understanding of material and system behavior.

  9. Hard turning micro-machine tool

    DOEpatents

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

    2013-10-22

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

  10. Hardness of decoding quantum stabilizer codes

    E-print Network

    Pavithran Iyer; David Poulin

    2013-10-11

    In this article we address the computational hardness of optimally decoding a quantum stabilizer code. Much like classical linear codes, errors are detected by measuring certain check operators which yield an error syndrome, and the decoding problem consists of determining the most likely recovery given the syndrome. The corresponding classical problem is known to be NP-complete, and a similar decoding problem for quantum codes is also known to be NP-complete. However, this decoding strategy is not optimal in the quantum setting as it does not take into account error degeneracy, which causes distinct errors to have the same effect on the code. Here, we show that optimal decoding of stabilizer codes is computationally much harder than optimal decoding of classical linear codes, it is #P.

  11. STAR Overview of Hard Probe Observables

    E-print Network

    Li Yi; for the STAR Collaboration

    2015-09-25

    Parton energy loss, quarkonium sequential melting and particle production from electromagnetic interactions are tools to study Quark Gluon Plasma properties. The STAR detector, with large acceptance at mid-rapidity, excellent particle identification and wide transverse momentum coverage, is able to study these probes in details. In Hard Probes 2015, the STAR collaboration reported measurements of reconstructed jets, heavy-flavor physics, di-lepton production and the performance of new detectors in seven presentations and one poster. Given the rich results from STAR, this overview report will focus on a few selected results on jets and $\\Upsilon$ measurements in Au+Au collisions at $\\sqrt{s_{\\rm NN}}=200\\,$GeV, $J/\\psi$ production in $p$+$p$ collisions at $\\sqrt{s_{\\rm NN}}=500\\,$GeV, and the di-electron spectrum in the low mass region from the Beam Energy Scan - Phase I.

  12. Escape Dynamics of Many Hard Disks

    E-print Network

    Tooru Taniguchi; Hiroki Murata; Shin-ichi Sawada

    2014-12-27

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

  13. Hard scattering and QCD Fundamentals at RHIC

    E-print Network

    M. J. Tannenbaum

    2008-06-02

    In 1998, at the 4th QCD workshop, Rolf Baier asked me whether jets could be measured in Au+Au collisions because he had a prediction of a QCD medium-effect (energy loss via soft gluon radiation induced by multiple scattering) on color-charged partons traversing a hot-dense-medium composed of screened color-charges. I reviewed the possibilities in a talk explaining that there was a general consensus that for Au+Au central collisions at $\\sqrt{s_{NN}}=200$ GeV, leading particles are the only way to find jets because of the large particle density. The good news was that hard-scattering in p-p collisions was originally observed by the method of leading particles and that these techniques could be used to study hard-scattering and jets in Au+Au collisions. Notably, I described ``How everything you want to know about jets can be found using 2-particle correlations''. In fact, the predicted ``jet quenching'' and other new phenomena were discovered by this method. However, this past year, I had to soften the statement to {\\em almost everything} because we found by explicit calculation in PHENIX that the away-side two-particle correlation $p_{T_a}$ spectrum from a $\\pi^0$ trigger with $p_{T_t}$ is not sensitive to the fragmentation function--overturning a belief dating from the seminal paper of Feynman, Field and Fox in 1977. A new formula was derived which showed that the shape of the $p_{T_a}$ spectrum depends only on the power $n$ of the parton invariant cross section so that NLO pQCD calculations of the two particle away-side correlations are, in fact, less sensitive to the shape of the fragmentation function than calculations of the inclusive $\\pi^0$ cross section.

  14. Coendangered hard-ticks: threatened or threatening?

    PubMed

    Mihalca, Andrei Daniel; Gherman, C?lin Mircea; Cozma, Vasile

    2011-01-01

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

  15. Identifying Those Whom Health Promotion Hardly Reaches: A Systematic Review.

    PubMed

    Sokol, Rebeccah; Fisher, Edwin; Hill, Julia

    2015-12-01

    To understand what circumstances lend groups to be recognized as hardly reached by health services and research, we systematically reviewed studies that identified their priority populations as hard to reach. We classified attributes of hardly reached groups into cultural/environmental, individual, and demographic domains. Of the 334 identified studies, 78.74% used attributes that were classified into the cultural/environmental, 74.85% the individual, and 50% the demographic domain to identify those hardly reached. Of all possible combinations of domains, the most common was the use of all three domains (28.74%). Overall, papers were more likely to use attributes to identify their hardly reached population that fell into more than one domain (74.85%) compared to only one domain (25.15%; ?(2), p < .0001). Through this review, we identified the attributes of those who have been identified as hardly reached in published research. No single attribute is used to identify those who are hardly reached. This reflects a socioecological perspective, emphasizing that both intrapersonal and external elements may cause interventions to fail to reach those intended. Moreover, the focus not on populations hardly reached but on the attributes of those hardly reached suggests objectives for interventions to reach them better. PMID:26405265

  16. INFLUENCE OF POST-CURE TREATMENTS ON HARDNESS AND MARGINAL ADAPTATION OF COMPOSITE RESIN INLAY RESTORATIONS: AN IN VITRO STUDY

    PubMed Central

    Poskus, Laiza Tatiana; Latempa, Antonio Marcelo Accetta; Chagas, Maurício Alves; da Silva, Eduardo Moreira; Leal, Mariana Pareira da Silva; Guimarães, José Guilherme Antunes

    2009-01-01

    Objectives: The purpose of this study was to evaluate the Vickers hardness number (VHN) and the in vitro marginal adaptation of inlay restorations of three hybrid composite resins (Filtek Z250, Opallis and Esthet-X) subjected to two post-cure treatments. Material and Methods: For the microhardness test, three different groups were prepared in accordance with the post-cure treatments: control group (only light cure for 40 s), autoclave group (light cure for 40 s + autoclave for 15 min at 130°C); and microwave group (light cure for 40 s + microwave for 3 min at 450 W). To assess the marginal adaptation, the composite resin was inserted incrementally into a mesial-occlusal-distal cavity brass mold and each increment light-cured for 40 s. A previous reading in micrometers was taken at the cervical wall, using a stereomicroscope magnifying glass equipped with a digital video camera and image-analysis software. Subsequently, the specimens were subjected to the post-cure treatments (autoclave and microwave) and a reading was taken again at the cervical wall. Data were compared using ANOVA for the hardness test, split-plot ANOVA for the adaptation assessment and Tukey's test for multiple comparisons. A significance level of 5% was adopted for all analyses. Results: The post-cure treatments increased the hardness of conventional composites (p<0.001) and the gap values of inlay restorations (p<0.01). Filtek Z250 showed higher hardness (p<0.001) and lower gap values than Opallis and Esthet-X (p<0.05). Gap values did not exceed 90 ?m for any of the experimental conditions. Conclusion: The post-cure treatments increased the VHN and the gap values on the cervical floor of composite resin inlays. Moreover, Filtek Z250 showed the best results, with higher hardness and lower gap values. PMID:20027437

  17. Example of quality assurance and optimization system for super hard materials turning

    NASA Astrophysics Data System (ADS)

    Kowalczyk, R.; Zebala, W.

    2014-11-01

    This paper introduces an example of automated intelligent system for super hard materials turning process that works according to a designed algorithm. Main task of the proposed system is to supervise the super hard materials turning process (acronym: ISSSHMT - Intelligent Supervision System of Super Hard Materials Turning) with the maximal metal removal rate Qvmax, the amplitude of natural tool wear and the measurement of values that define the state of the turning process (e.g. magnitude of cutting force, surface quality, temperature in workspace). Based on the measured values it is possible to select the optimal machining parameters (vc, ap, f), for which desired surface quality and dimensional precision can be achieved for the maximal metal removal rate Qvmax. Presented system (ISSSHMT) can be used for any CNC machine - accommodation for workspace and construction of the machine. An example of NC-code program that allows using the data acquired from the ISSSHMT system by a CNC machine control unit is presented. Optimization of the process and cost cutting can be achieved with the usage of proper target functions, for products machined with required precision class.

  18. Deposition, structure, and hardness of polycrystalline transition-metal nitride superlattice films

    SciTech Connect

    Chu, X.; Wong, M.S.; Sproul, W.D.; Barnett, S.A.

    1999-06-01

    Polycrystalline TiN/VN, NbN/VN, and TiN/NbN superlattices with periods {Lambda} between 2 and 160 nm were deposited onto steel substrates using an opposed-cathode reactive magnetron sputtering system. The nitrogen partial pressure and the substrate bias values were optimized in order to obtain dense stoichiometric films, which yielded the highest Vickers hardnesses H{sub V}. H{sub V} for TiN/VN and TiN/NbN superlattices reached maximum values of {approx}5000 kgf/mm{sup 2} at {Lambda}{approx}5{endash}10&hthinsp;nm, compared with {approx}2000 kgf/mm{sup 2} for homogeneous TiN, NbN, and VN films. In contrast, H{sub V}{approx}2000&hthinsp;kgf/mm{sup 2} was obtained for VN/NbN superlattices independent of {Lambda}. Model calculations in which the hardness enhancement was proportional to the difference in layer shear moduli gave good agreement with the data. The lack of hardness enhancement in VN/NbN indicates that any other hardening mechanisms, such as coherency strains and dislocation blocking by interfacial misfit dislocations, were not important. {copyright} {ital 1999 Materials Research Society.}

  19. Relative value health insurance.

    PubMed

    Korobkin, Russell

    2014-04-01

    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

  20. Value of Information spreadsheet

    SciTech Connect

    Trainor-Guitton, Whitney

    2014-05-12

    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.

  1. Values in action.

    PubMed

    Hearn, S A

    1997-01-01

    St. John Health System, Detroit, is committed to the values of wisdom, compassion, service to the neighbor, stewardship and servant leadership. When a patient walks through any one of the six St. John Hospitals, they see these words displayed many times. But what do they mean to the employees? Patients? The community? According to Anthony R. Tersigni, EdD, St. John president and CEO, "The values remind us of who we are and what our responsibilities are to the communities we serve." PMID:10168661

  2. Know Egg Values

    E-print Network

    Beanblossom, Floyd Z.; Clyatt, Gwendolyne

    1958-01-01

    does nc ggs detc ssible. )t affect ariorate Buy Wisely the food value of eggs. rapidly. Use them as Left over yolks or whites can be held in the refrigerator for a short time. Cover yolks with cold water; use within 2 or 3 days. Place. egg...) on ounces, peewee. the relative price spread for size classes at any give3 pri Table 1 lists these varying valu Medium 21 ox. 36 38 39 40 42 44 AA Excellent Table Eggs An egg possessing AA qual- ity as shown in the picture above covers a small area...

  3. Orientational ordering and phase behaviour of a binary mixture of hard spheres and hard spherocylinders

    E-print Network

    Liang Wu; Alexandr Malijevský; George Jackson; Erich A. Müller; Carlos Avendaño

    2015-08-16

    We study structure and fluid-phase behaviour of a binary mixture of hard spheres (HSs) and hard spherocylinders (HSCs) in isotropic and nematic states using the $NP_nAT$ ensemble Monte Carlo (MC) method in which a normal pressure tensor component is fixed in a system confined between two hard walls. The method allows one to estimate the location of the isotropic-nematic phase transition and to observe the asymmetry in the composition between the coexisting phases, with the expected increase of the HSC concentration in the nematic phase. This is in stark contrast with the previously reported MC simulations where a conventional isotropic $NPT$ ensemble was used. We further compare the simulation results with the theoretical predictions of two analytic theories that extend the original Parsons-Lee theory using the one-fluid and the many-fluid approximation [Malijevsk\\'y {\\it at al} J. Chem. Phys. \\textbf{129}, 144504 (2008)]. In the one-fluid version of the theory the properties of the mixture are mapped on an effective one-component HS system while in the many-fluid theory the components of the mixtures are represented as separate effective HS particles. The comparison reveals that both the one- and the many-fluid approaches provide a reasonably accurate quantitative description of the mixture including the predictions of the isotropic-nematic phase boundary and degree of orientational order of the HSC-HS mixtures.

  4. R-values

    SciTech Connect

    Roberts, K

    2009-03-03

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

  5. Complex oscillatory yielding in model hard sphere glasses

    NASA Astrophysics Data System (ADS)

    Petekidis, George; Koumakis, Nick

    2012-02-01

    The yielding behaviour of hard sphere glasses under large amplitude oscillatory shear has been studied by experimental rheology and Brownian Dynamics simulations. Here we focus on varying the frequency of oscillation probing the interplay between Brownian motion and shear-induced diffusion. Stress, structure and dynamics are followed by rheology and BD simulations Two frequency regimes are revealed: At low frequencies Brownian motion is dominant, assisting particles to escape their cage during a single step yielding process, identified by a peak of G'' at around the G'=G'' crossover. At high frequencies shear induced particle collisions causes cage breaking with the maximum energy dissipation marked by the G'' peak taking place beyond the G'=G'' crossover. Intermediate frequencies present a complex yielding behaviour influenced by both mechanisms that leads to a double peak in G'' that has not been reported before in HS glasses. The nonlinear response is quantified by the higher harmonics present in the stress signal. While at low frequencies the strength of higher harmonics reaches a constant value at high strains, in the intermediate and high frequency regime a non-monotonic behaviour is detected with characteristic large amplitude strains exhibiting apparent harmonic response.

  6. Hard X-ray polarimetry with Astrosat-CZTI

    NASA Astrophysics Data System (ADS)

    Vadawale, S. V.; Chattopadhyay, T.; Rao, A. R.; Bhattacharya, D.; Bhalerao, V. B.; Vagshette, N.; Pawar, P.; Sreekumar, S.

    2015-06-01

    X-ray polarimetry is largely an unexplored area of an otherwise mature field of X-ray astronomy. Except for a few early attempts during the 1970s, no dedicated X-ray polarimeter has been flown during the past four decades. On the other hand, the scientific value of X-ray polarization measurement has been well known for a long time, and there has been significant technical progress in developing sensitive X-ray polarimeters in recent years. But there are no approved dedicated X-ray polarimetric experiments to be flown in the near future, so it is important to explore the polarimetric capabilities of other existing or planned instruments and examine whether they can provide significant astrophysical polarization measurements. In this paper, we present experimental results to show that the CZTI instrument onboard the forthcoming Indian astronomy mission, Astrosat, will be able to provide sensitive measurements of X-ray polarization in the energy range of 100-300 keV. CZTI will be able to constrain any intrinsic polarization greater than ~40% for bright X-ray sources (>500 mCrab) within a short exposure of ~100 ks with a 3-sigma confidence level. We show that this seemingly "modest" sensitivity can play a very significant role in addressing long pending questions, such as the contribution of relativistic jets to hard X-rays in black hole binaries and X-ray emission mechanism and geometry in X-ray pulsars.

  7. Hard proximity induced superconducting gap in semiconductor - superconductor epitaxial hybrids

    NASA Astrophysics Data System (ADS)

    Jespersen, Thomas; Krogstrup, Peter; Ziino, Nino; Albrecht, Sven; Chang, Willy; Madsen, Morten; Johnson, Erik; Kuemmeth, Ferdinand; Nygård, Jesper; Marcus, Charles

    2015-03-01

    We present molecular beam epitaxy grown InAs semiconductor nanowires capped with a shell of aluminum (superconductor). The hybrid wires are grown without breaking vacuum, resulting in an epitaxial interface between the two materials as demonstrated by detailed transmission electron microscopy and simulations. The domain matching at the interface is discussed. Incorporating the epitaxial nanowire hybrids in electrical devices we performed detailed tunneling spectroscopy of the proximity induced superconducting gap in the InAs core at 20 mK. We find the sub-gap conductance being at least a factor 200 smaller than the normal state value (gap hardness). This is a significant improvement compared to devices fabricated by conventional lithographic methods and metal evaporation showing no more than a factor of ~ 5 . The epitaxial hybrids seem to solve the soft gap problem associated with the use of nanowire hybrids for future applications in topological quantum information based on Majorana zero modes. Research supported by Microsoft Station Q, Danish National Research Foundation, Villum Foundation, Lundbeck Foundation, and the European Commission.

  8. Quantum Searches in a Hard 2SAT Ensemble

    E-print Network

    Neuhaus Thomas

    2014-12-17

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

  9. Crystallization time scales for polydisperse hard-sphere fluids.

    PubMed

    Vargas, M Cristina; Pérez-Ángel, Gabriel

    2013-04-01

    We study the evolution of crystallization in dense mono- and polydisperse hard sphere fluids, initially quenched to an amorphous configuration. We use as signatures of crystallization both the decay of the reduced pressure Z and the increase in the local and global orientational order parameters Q[over ¯](6). For a given realization of the crystallization process these parameters show sudden changes, both large and small, separated by long periods of quiescence. However, averaging over a large number of realizations, a well-defined scenario for their evolution appears. We find an initial fast relaxation to a disordered state, followed by a period of slow variation, associated to the presence of nucleation events, followed by a fast change, composed of the growth of a few crystals with different orientations, and a final and slow coarsening in a domain-growth process. No clear scaling for this whole process was found. We also find that the transition to an stable glassy fluid is quite sharp as the polydispersity is increased, showing a probable first-order phase transition behavior. A well-defined boundary between crystallizing and permanently amorphous fluids should exist, at least for a region in packing fractions. We looked for segregation at large values of polydispersity, but no effects of this type were found. PMID:23679420

  10. Universal Jamming Phase Diagram in the Hard-Sphere Limit

    E-print Network

    Thomas K. Haxton; Michael Schmiedeberg; Andrea J. Liu

    2010-11-30

    We present a new formulation of the jamming phase diagram for a class of glass-forming fluids consisting of spheres interacting via finite-ranged repulsions at temperature $T$, packing fraction $\\phi$ or pressure $p$, and applied shear stress $\\Sigma$. We argue that the natural choice of axes for the phase diagram are the dimensionless quantities $T/p\\sigma^3$, $p\\sigma^3/\\epsilon$, and $\\Sigma/p$, where $T$ is the temperature, $p$ is the pressure, $\\Sigma$ is the stress, $\\sigma$ is the sphere diameter, $\\epsilon$ is the interaction energy scale, and $m$ is the sphere mass. We demonstrate that the phase diagram is universal at low $p\\sigma^3/\\epsilon$; at low pressure, observables such as the relaxation time are insensitive to details of the interaction potential and collapse onto the values for hard spheres, provided the observables are non-dimensionalized by the pressure. We determine the shape of the jamming surface in the jamming phase diagram, organize previous results in relation to the jamming phase diagram, and discuss the significance of various limits.

  11. The impulsive hard X-rays from solar flares

    NASA Technical Reports Server (NTRS)

    Leach, J.

    1984-01-01

    A technique for determining the physical arrangement of a solar flare during the impulsive phase was developed based upon a nonthermal model interpretation of the emitted hard X-rays. Accurate values are obtained for the flare parameters, including those which describe the magnetic field structure and the beaming of the energetic electrons, parameters which have hitherto been mostly inaccessible. The X-ray intensity height structure can be described readily with a single expression based upon a semi-empirical fit to the results from many models. Results show that the degree of linear polarization of the X-rays from a flaring loop does not exceed 25 percent and can easily and naturally be as low as the polarization expected from a thermal model. This is a highly significant result in that it supersedes those based upon less thorough calculations of the electron beam dynamics and requires that a reevaluation of hopes of using polarization measurements to discriminate between categories of flare models.

  12. Ti1-xAux Alloys: Hard Biocompatible Metals and Their Possible Applications

    NASA Astrophysics Data System (ADS)

    Svanidze, Eteri; Besara, Tiglet; Ozaydin, M. Fevzi; Xin, Yan; Han, Ke; Liang, Hong; Siegrist, Theo; Morosan, Emilia

    2015-03-01

    The search for new hard materials is often challenging from both theoretical and experimental points of view. Furthermore, using materials for biomedical applications calls for alloys with high biocompatibility which are even more sparse. The Ti1-xAux (0 . 22 <= x <= 0 . 8) exhibit extreme hardness and strength values, elevated melting temperatures (compared to those of constituent elements), reduced density compared to Au, high malleability, bulk metallicity, high biocompatibility, low wear, reduced friction, potentially high radio opacity, as well as osseointegration. All these properties render the Ti1-xAux alloys particularly useful for orthopedic, dental, and prosthetic applications, where they could be used as both permanent and temporary components. Additionally, the ability of Ti1-xAux alloys to adhere to ceramic parts could reduce the weight and cost of these components. The work at Rice was supported by NSF DMR 0847681 (E.M. and E.S.).

  13. Clusters in sedimentation equilibrium for an experimental hard-sphere-plus-dipolar Brownian colloidal system

    PubMed Central

    Newman, Hugh D.; Yethiraj, Anand

    2015-01-01

    In this work, we use structure and dynamics in sedimentation equilibrium, in the presence of gravity, to examine, via confocal microscopy, a Brownian colloidal system in the presence of an external electric field. The zero field equation of state (EOS) is hard sphere without any re-scaling of particle size, and the hydrodynamic corrections to the long-time self-diffusion coefficient are quantitatively consistent with the expected value for hard spheres. Care is taken to ensure that both the dimensionless gravitational energy, which is equivalent to a Peclet number Peg, and dipolar strength ? are of order unity. In the presence of an external electric field, anisotropic chain-chain clusters form; this cluster formation manifests itself with the appearance of a plateau in the diffusion coefficient when the dimensionless dipolar strength ??~?1. The structure and dynamics of this chain-chain cluster state is examined for a monodisperse system for two particle sizes. PMID:26323363

  14. Clusters in sedimentation equilibrium for an experimental hard-sphere-plus-dipolar Brownian colloidal system

    NASA Astrophysics Data System (ADS)

    Newman, Hugh D.; Yethiraj, Anand

    2015-09-01

    In this work, we use structure and dynamics in sedimentation equilibrium, in the presence of gravity, to examine, via confocal microscopy, a Brownian colloidal system in the presence of an external electric field. The zero field equation of state (EOS) is hard sphere without any re-scaling of particle size, and the hydrodynamic corrections to the long-time self-diffusion coefficient are quantitatively consistent with the expected value for hard spheres. Care is taken to ensure that both the dimensionless gravitational energy, which is equivalent to a Peclet number Peg, and dipolar strength ? are of order unity. In the presence of an external electric field, anisotropic chain-chain clusters form; this cluster formation manifests itself with the appearance of a plateau in the diffusion coefficient when the dimensionless dipolar strength ??~?1. The structure and dynamics of this chain-chain cluster state is examined for a monodisperse system for two particle sizes.

  15. Microstructural characterization and hardness properties of electric resistance welding titanium joints for dental applications.

    PubMed

    Ceschini, Lorella; Boromei, Iuri; Morri, Alessandro; Nardi, Diego; Sighinolfi, Gianluca; Degidi, Marco

    2015-06-01

    The electric resistance welding procedure is used to join a titanium bar with specific implant abutments in order to produce a framework directly in the oral cavity of the patient. This investigation studied the effects of the welding process on microstructure and hardness properties of commercially pure (CP2 and CP4) Ti components. Different welding powers and cooling procedures were applied to bars and abutments, normally used to produce the framework, in order to simulate the clinical intraoral welding procedure. The analyses highlighted that the joining process did not induce appreciable changes in the geometry of the abutments. However, because of unavoidable microstructural modifications in the welded zones, the hardness decreased to values lower than those of the unwelded CP2 and CP4 Ti grades, irrespective of the welding environments and parameters. PMID:26045042

  16. Stochastic Gyroresonant Acceleration for Hard Electron Spectra of Blazars: Effect of Damping of Cascading Turbulence

    E-print Network

    Kakuwa, Jun

    2015-01-01

    Stochastic acceleration of nonthermal electrons is investigated in the context of hard photon spectra of blazars. It is well known that this acceleration mechanism can produce a hard electron spectrum of $m \\equiv \\partial \\ln n_{\\rm e}(\\gamma)/\\partial \\ln \\gamma = 2$ with the high-energy cutoff, called an ultrarelativistic Maxwellian-like distribution, where $n_{\\rm e}(\\gamma)$ is an electron energy spectrum. We revisit the formation of this characteristic spectrum, considering a particular situation where the electrons are accelerated through gyroresonant interaction with magnetohydrodynamic wave turbulence driven by the turbulent cascade. By solving kinetic equations of the turbulent fields, electrons, and photons emitted via the synchrotron self-Compton (SSC) process, we demonstrate that in the non-test-particle treatment, the formation of a Maxwellian-like distribution is prevented by the damping effect on the turbulent fields due to the electron acceleration, at least unless an extreme parameter value ...

  17. Effects of various denture cleansers on surface roughness of hard permanent reline resins.

    PubMed

    Cakan, Umut; Kara, Ozlem; Kara, Haluk Baris

    2015-01-01

    The aim of this study was to investigate the influence of denture cleansers on surface roughness (Ra, µm) of two hard permanent reline resins and a conventional acrylic denture base resin. Fifty specimens of each material, measuring 10 mm×2 mm were randomly divided into 1 control and 4 experimental subgroups (n=10). Surface roughness values were measured using profilometer before and after immersion in distilled water and in 4 different denture cleansers for 8 h for 140 days. The Kruskal Wallis and Wilcoxon Signed Ranks tests were used for comparison among groups with a significance level of ?=0.05. Immersion in denture cleansers significantly increased the surface roughness of reline resins and the difference among the cleansers was statistically significant (p=0.059). Denture cleansers can cause significant surface roughness alterations on hard permanent reline resins and denture base resin where their effect may differ according to the selected resin material. PMID:25740306

  18. Clusters in sedimentation equilibrium for an experimental hard-sphere-plus-dipolar Brownian colloidal system

    E-print Network

    Hugh D. Newman; Anand Yethiraj

    2015-07-30

    In this work, we use structure and dynamics in sedimentation equilibrium, in the presence of gravity, to examine, $via$ confocal microscopy, a Brownian colloidal system in the presence of an external electric field. The zero field equation of state (EOS) is hard sphere without any re-scaling of particle size, and the hydrodynamic corrections to the long-time self-diffusion coefficient are quantitatively consistent with the expected value for hard spheres. Care is taken to ensure that both the dimensionless gravitational energy, which is equivalent to a Peclet number $Pe_g$, and dipolar strength $\\Lambda$ are of order unity. In the presence of an external electric field, anisotropic chain-chain clusters form; this cluster formation manifests itself with the appearance of a plateau in the diffusion coefficient when the dimensionless dipolar strength $\\Lambda \\sim 1$. The structure and dynamics of this chain-chain cluster state is examined for a monodisperse system for two particle sizes.

  19. The Value of Trust to Nursing.

    PubMed

    Rutherford, Marcella M

    2014-01-01

    Trust, one of nursing's intangible assets, impacts nurses' ability to form meaningful relationships with patients and this connection positively impacts health outcomes. Linking trust to the fabric of nursing and investing in its measurement will become essential to nursing's valuation and the resulting investment in nursing. Trust, as nursing's core value, should be fostered by nurse educators as they prepare the next generation of nurses. Nurse administrators should connect the trust a patient has for his or her nurse and patient cooperation and honest transparent communication between providers and the patient. Banking trust as a valuable nursing asset will substantiate nursing's marketing and support its worth. Nursing's trustworthiness is an intangible asset that warrants protection, as trust once lost is hard to recapture. PMID:26267958

  20. Technostress and Library Values.

    ERIC Educational Resources Information Center

    Gorman, Michael

    2001-01-01

    Discusses information overload and society's and libraries' responses to technology. Considers eight values that libraries should focus on and how they relate to technology in libraries: democracy, stewardship, service, intellectual freedom, privacy, rationalism, equity of access, and building harmony and balance. (LRW)

  1. Materialistic Values and Goals.

    PubMed

    Kasser, Tim

    2016-01-01

    Materialism comprises a set of values and goals focused on wealth, possessions, image, and status. These aims are a fundamental aspect of the human value/goal system, standing in relative conflict with aims concerning the well-being of others, as well as one's own personal and spiritual growth. Substantial evidence shows that people who place a relatively high priority on materialistic values/goals consume more products and incur more debt, have lower-quality interpersonal relationships, act in more ecologically destructive ways, have adverse work and educational motivation, and report lower personal and physical well-being. Experimentally activating materialistic aims causes similar outcomes. Given these ills, researchers have investigated means of decreasing people's materialism. Successful interventions encourage intrinsic/self-transcendent values/goals, increase felt personal security, and/or block materialistic messages from the environment. These interventions would likely be more effective if policies were also adopted that diminished contemporary culture's focus on consumption, profit, and economic growth. PMID:26273896

  2. Researching Values in Education.

    ERIC Educational Resources Information Center

    Halliday, John

    2002-01-01

    Considers methodological issues that arise when values form the main focus of empirical educational research. Includes discussion of the idea that social science, in general, and educational research, in particular, are forms of moral inquiry. Outlines a methodology of educational research, drawing from work by Imre Lakatos, Alasdair MacIntyre,…

  3. Prevent and "British Values"

    ERIC Educational Resources Information Center

    Kenny, Alex; Ghale, Baljeet

    2015-01-01

    At the recent National Union of Teachers' conference the role of the Prevent strategy and the introduction of "British Values" in the Office for Standards in Education, Children's Services and Skills framework emerged as key issues for delegates. Two of the speeches made at the conference are presented here.

  4. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  5. Ethics and Value Education

    ERIC Educational Resources Information Center

    Callahan, Daniel

    1978-01-01

    The teaching of ethics and values is a concern of American education. Scientific and technological developments and the responsibilities of professional life and of personal morality are discussed. Steps to a quality program in ethics, and the need for a theoretical framework are also addressed. (SW)

  6. Valuing Higher Education

    ERIC Educational Resources Information Center

    Pillay, Gerald J.

    2009-01-01

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

  7. Values in Literature: Primary.

    ERIC Educational Resources Information Center

    Sterling, Mary Ellen

    Offering students some thinking and coping tools they can use to make sound decisions based on strong values, this resource book presents numerous selections from children's literature and suggested activities and projects. The book begins with a brief introduction, advice to teachers on using the book, ways to make the classroom more conducive to…

  8. Valuing the Environment, Elementary.

    ERIC Educational Resources Information Center

    Charlotte-Mecklenburg Public Schools, Charlotte, NC.

    This guide was developed for use in grades K-6 as an enrichment program based on clarifying values. The program, designed by teachers, aims to develop in the student a greater awareness and understanding of the community, themselves, and the earth. The program includes environmental encounters and a chart of topical themes and conceptual themes.…

  9. Whose Religious Values?

    ERIC Educational Resources Information Center

    Marshall, Joanne M.

    2008-01-01

    Public schools, since their founding in America in 1647, have reflected the demographic characteristics of the communities in which they are located. Because the United States has, until recently, been mostly Protestant Christian, many schooling practices have built upon the values of this faith. Pupils have sung Christmas songs at Christmas…

  10. Valuing different human lives.

    PubMed

    Goodwin, Geoffrey P; Landy, Justin F

    2014-04-01

    Do people think of the value of all human lives as equivalent irrespective of age? Affirmations of the equal value of all human lives are culturally prominent, yet much evidence points to the fact that the young are often prioritized over the old in life-and-death decision-making contexts. Studies 1-3 aimed to reconcile this tension by showing that although individuals are seen as more equal with respect to negative rights not to be harmed or killed (though not completely equal), they are seen as less equal with respect to positive rights to be aided or saved. Age exerts a large and systematic impact on decisions about who to save and about whose death is more tragic, suggesting that individuals are seen as possessing differing amounts of contingent value. These initial studies also yielded the novel finding that, although children are prioritized over adults, older children are often prioritized over younger children. Study 4 replicated this finding with a think-aloud methodology; the study showed that the preference for older children appears to be driven by their having had more invested in their lives, their better developed social relations, and their greater understanding of death. Studies 5a-5c demonstrated the independent causal effects of each of these variables on judgments of life's value. Finally, in Studies 6 and 7, mediation methods were used to show that older children's more meaningful social relations primarily explain the greater value of older than of younger children. These findings have implications for bioethics and medical policy. PMID:23647311

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  12. Go endgames are PSPACE-hard David Wolfe

    E-print Network

    Wolfe, David

    Go endgames are PSPACE-hard David Wolfe #3; Abstract In a Go endgame, each local area of play has techniques from combinatorial game theory, we prove that the Go endgame is PSPACE-hard. Keywords: Go, PSPACE, endgame, games. 1 Introduction Go is an ancient game which has been played for several millennia through

  13. HARD RED SPRING WHEAT QUALITY REPORT: 2000/2001 CROP.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercially grown cultivars and experimental lines of hard red spring wheat were grown by breeders at cooperative experiment stations throughout the major spring wheat growing regions of the United States. Hard spring wheat was tested for kernel, milling, flour, dough, and baking quality. In 2000...

  14. 21 CFR 133.148 - Hard grating cheeses.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Hard grating cheeses. 133.148 Section 133.148 Food... HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.148 Hard grating cheeses. (a) The cheeses for which definitions and standards...

  15. 21 CFR 133.148 - Hard grating cheeses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Hard grating cheeses. 133.148 Section 133.148 Food... HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.148 Hard grating cheeses. (a) The cheeses for which definitions and standards...

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

    EPA Science Inventory

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

  17. When Are Elections with Few Candidates Hard to Manipulate?

    E-print Network

    Lang, Jérôme

    When Are Elections with Few Candidates Hard to Manipulate? VINCENT CONITZER Duke University TUOMAS protocols are manipulable. One could try to avoid manipulation by using protocols where determining a beneficial manipulation is hard. Especially among computational agents, it is reasonable to measure

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. A NEW MODEL FOR PERFORMANCE PREDICTION OF HARD ROCK TBMS.

    E-print Network

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

  20. Employing the Hard-Core: Internal Organizational Effects.

    ERIC Educational Resources Information Center

    Champagne, J. E.; And Others

    This paper is presented with the hope that those studying or directly involved in the utilization of hard-core persons in employment may gain insights which may make their tasks easier and more productive. It is written in a readable and non-technical nature and integrates experiences of hard-core utilization with accepted organization theory.…

  1. Educating Hard of Hearing Children. Special Education in Transition 2.

    ERIC Educational Resources Information Center

    Ross, Mark, Ed.; Nober, Linda W., Ed.

    Viewpoints of an audiologist, speech-language pathologist, special educator, classroom teacher, and parent are presented in the book on the implications of P.L. 94-142, the Education for All Handicapped Children Act, for hard of hearing students. In the introduction, M. Ross considers the status of many hard of hearing students, noting the…

  2. 20 The Harder Problem of Consciousness I The Hard Problem

    E-print Network

    Pylyshyn, Zenon

    20 The Harder Problem of Consciousness I The Hard Problem T. H. Huxley famously said ``How to ex- plain a state of consciousness in terms of its neurological basis. This is the Hard Prob- lem of Consciousness.2 The aim of this paper is to present another problem of consciousness. The Harder Problem, as I

  3. Sneaking Up On the Hard Problem of Consciousness Benjamin Kuipers

    E-print Network

    Kuipers, Benjamin

    Sneaking Up On the Hard Problem of Consciousness Benjamin Kuipers Computer Science Department aspects of consciousness -- the Easy Problem, the Intentionality Problem, and the Hard Problem -- from cope with its demands. Introduction Consciousness is one of the most intriguing and mysterious aspects

  4. Quantitative Trait Loci Mapping of Seed Hardness in Soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean seeds with undesirable texture cause processing complications in soyfood production. Seed hardness is an important quality attribute for food-grade soybeans. The objective of this study was to identify QTL associated with seed hardness in soybean. Three generations of F2-derived lines (159 F...

  5. Critical Configurations of Hard Disks on the Torus

    Energy Science and Technology Software Center (ESTSC)

    2013-04-16

    CCHDT constructs and classifies various arrangements of hard disks of a single radius places on the unit square with periodic boundary conditions. Specifially, a given configuration is evolved to the nearest critical point on a smoothed hard disk energy fuction, and is classified by the adjacency matrix of the canonically labelled contact graph.

  6. The Simplified Partial Digest Problem: Hardness and a Probabilistic Analysis

    E-print Network

    Bejerano, Gill

    The Simplified Partial Digest Problem: Hardness and a Probabilistic Analysis Zoë Abrams1 and Ho site locations of the enzyme. Two common approaches are the Double Digest Problem and the Partial Digest Problem. The Double Digest Problem is known to be NP-Complete[4], but the hardness of the Partial

  7. Hard loop effective theory of the (anisotropic) quark gluon plasma

    E-print Network

    A. Rebhan

    2008-11-19

    The generalization of the hard thermal loop effective theory to anisotropic plasmas is described with a detailed discussion of anisotropic dispersion laws and plasma instabilities. The numerical results obtained in real-time lattice simulations of the hard loop effective theory are reviewed, both for the stationary anisotropic case and for a quark-gluon plasma undergoing boost-invariant expansion.

  8. Hardness Analysis. Training Module 5.215.2.77.

    ERIC Educational Resources Information Center

    Bonte, John L.; Davidson, Arnold C.

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

  9. Puroindolines: the molecular genetic basis of wheat grain hardness.

    PubMed

    Morris, Craig F

    2002-01-01

    The variation in grain hardness is the single most important trait that determines end-use quality of wheat. Grain texture classification is based primarily on either the resistance of kernels to crushing or the particle size distribution of ground grain or flour. Recently, the molecular genetic basis of grain hardness has become known, and it is the focus of this review. The puroindoline proteins a and b form the molecular basis of wheat grain hardness or texture. When both puroindolines are in their 'functional' wild state, grain texture is soft. When either one of the puroindolines is absent or altered by mutation, then the result is hard texture. In the case of durum wheat which lacks puroindolines, the texture is very hard. Puroindolines represent the molecular-genetic basis of the Hardness locus on chromosome 5DS and the soft (Ha) and hard (ha) alleles present in hexaploid bread wheat varieties. To date, seven discrete hardness alleles have been described for wheat. All involve puroindoline a or b and have been designated Pina-D1b and Pinb-D1b through Pinb-D1g. A direct role of a related protein, grain softness protein (as currently defined), in wheat grain texture has yet to be demonstrated. PMID:11999840

  10. The Role of Water Temperature in Hard Clam Aquaculture1

    E-print Network

    Florida, University of

    FA151 The Role of Water Temperature in Hard Clam Aquaculture1 Kerry Weber, Leslie Sturmer, Elise of water temperature in hard clam production in Florida. A glossary of terms is provided at the end of the document. What is water temperature? Temperature is the measurement of heat in a material and is related

  11. Amphiphilic hard body mixtures Matthias Schmidt and Christian von Ferber

    E-print Network

    Schmidt, Matthias

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

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

    NASA Astrophysics Data System (ADS)

    Lech, Andrew Thomas

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

  13. Sampling from a polytope and hard-disk Monte Carlo

    E-print Network

    Sebastian C. Kapfer; Werner Krauth

    2013-01-21

    The hard-disk problem, the statics and the dynamics of equal two-dimensional hard spheres in a periodic box, has had a profound influence on statistical and computational physics. Markov-chain Monte Carlo and molecular dynamics were first discussed for this model. Here we reformulate hard-disk Monte Carlo algorithms in terms of another classic problem, namely the sampling from a polytope. Local Markov-chain Monte Carlo, as proposed by Metropolis et al. in 1953, appears as a sequence of random walks in high-dimensional polytopes, while the moves of the more powerful event-chain algorithm correspond to molecular dynamics evolution. We determine the convergence properties of Monte Carlo methods in a special invariant polytope associated with hard-disk configurations, and the implications for convergence of hard-disk sampling. Finally, we discuss parallelization strategies for event-chain Monte Carlo and present results for a multicore implementation.

  14. NET ECONOMIC VALUES OF RECREATIONISTS

    E-print Network

    #12;NET ECONOMIC VALUES OF RECREATIONISTS FOR OUTDOOR EXPERIENCES IN THE FRASER RIVER BASIN Crane of Economic Values 2.1 Water Resource Economic Values 2.2 Net Economic Values of Recreationists 2.3 Estimating Net Economic Value 2.4 Estimation Problems Review of Net Economic Value Estimates 3.1 Summary

  15. Compressibility and hardness of Co-based bulk metallic glass: A combined experimental and density functional theory study

    SciTech Connect

    Wang Jianfeng; Li Ran; Xu Tao; Li Yan; Liu Zengqian; Huang Lu; Hua Nengbin; Zhang Tao; Xiao Ruijuan; Li Gong; Li Yanchun

    2011-10-10

    An incompressible Co{sub 54}Ta{sub 11}B{sub 35} bulk metallic glass (BMG) was investigated using in situ high-pressure synchrotron diffraction and nanoindendation. The elastic constants were deduced from the experiments based on the isotropic model. The Vickers hardness was measured to be 17.1 GPa. The elastic moduli and hardness are the highest values known in BMGs. The theoretically calculated elastic properties by density-functional study were well consistent with experimental measurements. The analysis of charge density and bonding character indicates the covalent character of Co-B and B-B bonds, underlying the unusually high elastic modulus and hardness in this material.

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  17. Gross Morphometric Studies on the Tongue, Buccal Cavity and Hard Palate of the Fruit Bat (Eidolon helvum).

    PubMed

    Igado, O O; Omobowale, T O; Ajadi, R A; Nottidge, H O

    2015-08-01

    This study was designed to assess the gross morphometric studies of the tongue, hard palate and buccal cavity of the fruit bat (Eidolon helvum). Sixty bats of both sexes were used for this study. The tongue was excised, and the weight and various linear measurements were determined. Linear measurements were also determined on the hard palate. The gross distribution of the lingual papillae was observed to be the same in both sexes; values obtained for the weight and length of the tongue were higher in the females, although no statistically significant differences were observed (P > 0.05). The number of ridges on the hard palate displayed sexual dimorphism. Results obtained from this study may find application in the field of comparative and clinical anatomy of wildlife and also in feeding physiology. PMID:25115593

  18. The value of snow cover

    NASA Astrophysics Data System (ADS)

    Sokratov, S. A.

    2009-04-01

    Snow is the natural resource, like soil and water. It has specific properties which allow its use not just for skiing but also for houses cooling in summer (Swedish experience), for air fields construction (Arctic and Antarctic), for dams (north of Russia), for buildings (not only snow-houses of some Polar peoples but artistic hotel attracting tourists in Sweden), and as art material (Sapporo snow festival, Finnish events), etc. "Adjustment" of snow distribution and amount is not only rather common practice (avalanche-protection constructions keeping snow on slopes) but also the practice with long history. So-called "snow irrigation" was used in Russia since XIX century to protect winter crop. What is now named "artificial snow production", is part of much larger pattern. What makes it special—it is unavoidable in present climate and economy situation. 5% of national income in Austria is winter tourism. 50% of the economy in Savoy relay on winter tourism. In terms of money this can be less, but in terms of jobs and income involved this would be even more considerable in Switzerland. As an example—the population of Davos is 14000 in Summer and 50000 in Winter. Skiing is growing business. In present time you can find ski slopes in Turkey and Lebanon. To keep a cite suitable for attracting tourists you need certain amount of sunny days and certain amount of snow. The snow cannons are often the only way to keep a place running. On the other hand, more artificial snow does not necessary attract more tourists, while heavy natural snowfall does attract them. Artificial snow making is costly and requires infrastructure (ponds and electric lines) with very narrow range of weather conditions. Related companies are searching for alternatives and one of them can be "weather regulation" by distribution of some chemical components in clouds. It did not happen yet, but can happen soon. The consequences of such interference in Nature is hardly known. The ski tourism is not the only and not even the main outcome from snow cover use. The value of snow cover for agriculture, water resources, industry and transportation is so naturally inside the activities that is not often quantified. However, any considerations of adaptation strategies for climate change with changing snow conditions need such quantification.

  19. Unraveling Quantum Annealers using Classical Hardness

    PubMed Central

    Martin-Mayor, Victor; Hen, Itay

    2015-01-01

    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, commonly referred to as ‘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 experimental quantum annealers from their classical thermal counterparts. Inspired by recent results in spin-glass theory that recognize ‘temperature chaos’ as the underlying mechanism responsible for the computational intractability of hard optimization problems, we devise a general method to quantify the performance of quantum annealers on optimization problems suffering from varying degrees of temperature chaos: A superior performance of quantum annealers over classical algorithms on these may allude to the role that quantum effects play in providing speedup. We utilize our method to experimentally study the D-Wave Two chip on different temperature-chaotic problems and find, surprisingly, that its performance scales unfavorably as compared to several analogous classical algorithms. We detect, quantify and discuss several purely classical effects that possibly mask the quantum behavior of the chip. PMID:26483257

  20. Sublittoral hard substrate communities off Helgoland

    NASA Astrophysics Data System (ADS)

    de Kluijver, M. J.

    1991-09-01

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

  1. Dynamics of hard sphere colloidal dispersions

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  2. Hard ticks (Acari, Ixodidae) of Croatia

    PubMed Central

    Kr?mar, Stjepan

    2012-01-01

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

  3. Computational Modeling Develops Ultra-Hard Steel

    NASA Technical Reports Server (NTRS)

    2007-01-01

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

  4. Monodisperse hard rods in external potentials.

    PubMed

    Bakhti, Benaoumeur; Karbach, Michael; Maass, Philipp; Müller, Gerhard

    2015-10-01

    We consider linear arrays of cells of volume V_{c} populated by monodisperse rods of size ?V_{c},?=1,2,..., subject to hardcore exclusion interaction. Each rod experiences a position-dependent external potential. In one application we also examine effects of contact forces between rods. We employ two distinct methods of exact analysis with complementary strengths and different limits of spatial resolution to calculate profiles of pressure and density on mesoscopic and microscopic length scales at thermal equilibrium. One method uses density functionals and the other statistically interacting vacancy particles. The applications worked out include gravity, power-law traps, and hard walls. We identify oscillations in the profiles on a microscopic length scale and show how they are systematically averaged out on a well-defined mesoscopic length scale to establish full consistency between the two approaches. The continuum limit, realized as V_{c}?0,??? at nonzero and finite ?V_{c}, connects our highest-resolution results with known exact results for monodisperse rods in a continuum. We also compare the pressure profiles obtained from density functionals with the average microscopic pressure profiles derived from the pair distribution function. PMID:26565173

  5. Hazards of the 'hard cash': hypersensitivity pneumonitis.

    PubMed

    Kupeli, Elif; Karnak, Demet; Sak, Serpil Dizbay; Kayacan, Oya

    2010-01-01

    Hypersensitivity pneumonitis (HP) is a nonimmunoglobulin E-related immune-mediated parenchymal lung disease. A 45-year-old woman who was a lifelong nonsmoker with a six-month history of frequent episodes of cough and dyspnea was admitted to hospital. She had been working as a money counter for 20 years at a central bank. Bibasilar crackles on lung auscultation, ground-glass opacities and a mosaic pattern on high-resolution computed tomography, restrictive abnormality on pulmonary function tests and mild hypoxemia were the prominent findings. Bronchoalveolar lavage fluid analysis revealed a predominance of CD4-positive T cells, and she tested positive on her natural challenge test. She was diagnosed with subacute HP based on established criteria. She was advised to discontinue counting fresh banknotes. Prednisolone was commenced, then tapered to discontinue in the ensuing six months. Clinical and radiological improvement was achieved within two months. To the authors' knowledge, the present report is the first to describe 'hard cash HP', possibly caused by chipping dust or printing dye. PMID:21038004

  6. Hazards of the ‘hard cash’: Hypersensitivity pneumonitis

    PubMed Central

    Kupeli, Elif; Karnak, Demet; Sak, Serpil Dizbay; Kayacan, Oya

    2010-01-01

    Hypersensitivity pneumonitis (HP) is a nonimmunoglobulin E-related immune-mediated parenchymal lung disease. A 45-year-old woman who was a lifelong nonsmoker with a six-month history of frequent episodes of cough and dyspnea was admitted to hospital. She had been working as a money counter for 20 years at a central bank. Bibasilar crackles on lung auscultation, ground-glass opacities and a mosaic pattern on high-resolution computed tomography, restrictive abnormality on pulmonary function tests and mild hypoxemia were the prominent findings. Bronchoalveolar lavage fluid analysis revealed a predominance of CD4-positive T cells, and she tested positive on her natural challenge test. She was diagnosed with subacute HP based on established criteria. She was advised to discontinue counting fresh banknotes. Prednisolone was commenced, then tapered to discontinue in the ensuing six months. Clinical and radiological improvement was achieved within two months. To the authors’ knowledge, the present report is the first to describe ‘hard cash HP’, possibly caused by chipping dust or printing dye. PMID:21038004

  7. The Hard X ray Telescope Mission

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul

    1997-01-01

    The Hard X Ray Telescope (HXT) was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity and much better angular resolution in the 10100 keV band, and (3) higher sensitivity for detecting gamma ray lines of known energy in the 100 keV to 1 MeV band. The institutions collaborating in the study are: Smithsonian Astrophysical Observatory, Marshall Space Flight Center, Naval Research Laboratory, Goddard Space Flight Center, Argonne National Laboratory, Danish Space Research Institute, Osservatorio Astronomica di Brera (Merate), and Centre d'Etudes Spatiale des Rayonnements (Toulouse). The instrumentation includes several grazing incidence double conical telescopes with multilayer coatings that focus up to 100 keV and a single Laue crystal telescope that functions to 1 MeV. The detectors are CCDs, and germanium, and/or CdZnTe position sensitive arrays.

  8. Unraveling Quantum Annealers using Classical Hardness

    NASA Astrophysics Data System (ADS)

    Martin-Mayor, Victor; Hen, Itay

    2015-10-01

    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, commonly referred to as ‘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 experimental quantum annealers from their classical thermal counterparts. Inspired by recent results in spin-glass theory that recognize ‘temperature chaos’ as the underlying mechanism responsible for the computational intractability of hard optimization problems, we devise a general method to quantify the performance of quantum annealers on optimization problems suffering from varying degrees of temperature chaos: A superior performance of quantum annealers over classical algorithms on these may allude to the role that quantum effects play in providing speedup. We utilize our method to experimentally study the D-Wave Two chip on different temperature-chaotic problems and find, surprisingly, that its performance scales unfavorably as compared to several analogous classical algorithms. We detect, quantify and discuss several purely classical effects that possibly mask the quantum behavior of the chip.

  9. Monodisperse hard rods in external potentials

    NASA Astrophysics Data System (ADS)

    Bakhti, Benaoumeur; Karbach, Michael; Maass, Philipp; Müller, Gerhard

    2015-10-01

    We consider linear arrays of cells of volume Vc populated by monodisperse rods of size ? Vc,? =1 ,2 ,... , subject to hardcore exclusion interaction. Each rod experiences a position-dependent external potential. In one application we also examine effects of contact forces between rods. We employ two distinct methods of exact analysis with complementary strengths and different limits of spatial resolution to calculate profiles of pressure and density on mesoscopic and microscopic length scales at thermal equilibrium. One method uses density functionals and the other statistically interacting vacancy particles. The applications worked out include gravity, power-law traps, and hard walls. We identify oscillations in the profiles on a microscopic length scale and show how they are systematically averaged out on a well-defined mesoscopic length scale to establish full consistency between the two approaches. The continuum limit, realized as Vc?0 ,? ?? at nonzero and finite ? Vc , connects our highest-resolution results with known exact results for monodisperse rods in a continuum. We also compare the pressure profiles obtained from density functionals with the average microscopic pressure profiles derived from the pair distribution function.

  10. Escape dynamics of many hard disks.

    PubMed

    Taniguchi, Tooru; Murata, Hiroki; Sawada, Shin-Ichi

    2014-11-01

    Many-particle effects in escapes of hard disks from a square box via a hole are discussed in a viewpoint of dynamical systems. Starting from N disks in the box at the initial time, we calculate the probability P_{n}(t) for at least n disks to remain inside the box at time t for n=1,2,...,N. At early times, the probabilities P_{n}(t),n=2,3,...,N-1, are described by superpositions of exponential decay functions. On the other hand, after a long time the probability P_{n}(t) shows a power-law decay ?t^{-2n} for n?1, in contrast to the fact that it decays with a different power law ?t^{-n} for cases without any disk-disk collision. Chaotic or nonchaotic properties of the escape systems are discussed by the dynamics of a finite-time largest Lyapunov exponent, whose decay properties are related with those of the probability P_{n}(t). PMID:25493874

  11. Unraveling Quantum Annealers using Classical Hardness.

    PubMed

    Martin-Mayor, Victor; Hen, Itay

    2015-01-01

    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, commonly referred to as '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 experimental quantum annealers from their classical thermal counterparts. Inspired by recent results in spin-glass theory that recognize 'temperature chaos' as the underlying mechanism responsible for the computational intractability of hard optimization problems, we devise a general method to quantify the performance of quantum annealers on optimization problems suffering from varying degrees of temperature chaos: A superior performance of quantum annealers over classical algorithms on these may allude to the role that quantum effects play in providing speedup. We utilize our method to experimentally study the D-Wave Two chip on different temperature-chaotic problems and find, surprisingly, that its performance scales unfavorably as compared to several analogous classical algorithms. We detect, quantify and discuss several purely classical effects that possibly mask the quantum behavior of the chip. PMID:26483257

  12. Thailand: refining cultural values.

    PubMed

    Ratanakul, P

    1990-01-01

    In the second of a set of three articles concerned with "bioethics on the Pacific Rim," Ratanakul, director of a research center for Southeast Asian cultures in Thailand, provides an overview of bioethical issues in his country. He focuses on four issues: health care allocation, AIDS, determination of death, and euthanasia. The introduction of Western medicine into Thailand has brought with it a multitude of ethical problems created in part by tension between Western and Buddhist values. For this reason, Ratanakul concludes that "bioethical enquiry in Thailand must not only examine ethical dilemmas that arise in the actual practice of medicine and research in the life sciences, but must also deal with the refinement and clarification of applicable Thai cultural and moral values." PMID:2318624

  13. Global Value Trees

    PubMed Central

    Zhu, Zhen; Puliga, Michelangelo; Cerina, Federica; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    The fragmentation of production across countries has become an important feature of the globalization in recent decades and is often conceptualized by the term “global value chains” (GVCs). When empirically investigating the GVCs, previous studies are mainly interested in knowing how global the GVCs are rather than how the GVCs look like. From a complex networks perspective, we use the World Input-Output Database (WIOD) to study the evolution of the global production system. We find that the industry-level GVCs are indeed not chain-like but are better characterized by the tree topology. Hence, we compute the global value trees (GVTs) for all the industries available in the WIOD. Moreover, we compute an industry importance measure based on the GVTs and compare it with other network centrality measures. Finally, we discuss some future applications of the GVTs. PMID:25978067

  14. Bivariate extreme value distributions

    NASA Technical Reports Server (NTRS)

    Elshamy, M.

    1992-01-01

    In certain engineering applications, such as those occurring in the analyses of ascent structural loads for the Space Transportation System (STS), some of the load variables have a lower bound of zero. Thus, the need for practical models of bivariate extreme value probability distribution functions with lower limits was identified. We discuss the Gumbel models and present practical forms of bivariate extreme probability distributions of Weibull and Frechet types with two parameters. Bivariate extreme value probability distribution functions can be expressed in terms of the marginal extremel distributions and a 'dependence' function subject to certain analytical conditions. Properties of such bivariate extreme distributions, sums and differences of paired extremals, as well as the corresponding forms of conditional distributions, are discussed. Practical estimation techniques are also given.

  15. Global value trees.

    PubMed

    Zhu, Zhen; Puliga, Michelangelo; Cerina, Federica; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    The fragmentation of production across countries has become an important feature of the globalization in recent decades and is often conceptualized by the term "global value chains" (GVCs). When empirically investigating the GVCs, previous studies are mainly interested in knowing how global the GVCs are rather than how the GVCs look like. From a complex networks perspective, we use the World Input-Output Database (WIOD) to study the evolution of the global production system. We find that the industry-level GVCs are indeed not chain-like but are better characterized by the tree topology. Hence, we compute the global value trees (GVTs) for all the industries available in the WIOD. Moreover, we compute an industry importance measure based on the GVTs and compare it with other network centrality measures. Finally, we discuss some future applications of the GVTs. PMID:25978067

  16. Measuring Value in Healthcare

    E-print Network

    Gardner, Christopher

    2008-01-01

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

  17. Education: A Core Value

    NASA Astrophysics Data System (ADS)

    Carroll, William F., Jr.

    2001-09-01

    1. Teaching our Children. ACS should develop an intensive course in modern teaching methods, challenges and responsibilities, and press for streamlined teacher certification procedures for advanced degree or life experience chemists.
    2. Teaching our Future Colleagues. As President I will encourage companies to make scientists with special skills available to universities, and will encourage universities to utilize these scientists to round out areas of study not covered by their existing faculty.
    3. Teaching our Members. ACS should develop functional and management-related courses for scientists to facilitate career advancement from the bench to research management or from science to business.
    4. Teaching the Public. The President is the most visible representative of the Society, and should devote significant time to communication with lay audiences.
    Value Matters. My first priority as President will be to increase value creation, communication and quantification so members can easily identify programs that fill their needs and exceed their expectations.

  18. Bhutan National Values Assessment

    E-print Network

    Evans, Steve

    2008-01-01

    /violence (6 votes), drug addiction (9 votes), corruption (9 votes), autocracy (9 votes), poverty (10 votes), unemployment (14 votes), and environmental pollution (15 votes). • Level 2 – Relationships (36 votes, 1% of total): racial/ethnic discrimination... • Protection for the rights of the people to make political choices • Moral structure that provides guidance and encourages comfort Bhutan’s top national value perceived by its people is “continuous improvement,” and there is a strong concentration...

  19. Complex-Valued Autoencoders

    PubMed Central

    Baldi, Pierre; Lu, Zhiqin

    2012-01-01

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

  20. Minimum Critical Values Study

    SciTech Connect

    Fox, P.B.

    2005-07-11

    This report provides minimum critical values for various 30-cm water-reflected uranium and plutonium oxide and nitrate aqueous mixtures as calculated by the SCALE CSAS1X sequence using the 238-group ENDF/B-V neutron cross-section library. The minimum values were determined through parametric searches in one-dimensional geometry. The calculations have been performed to obtain the minimum values: critical volume and mass for spheres, critical radius for cylinders, critical thickness for slabs, and minimum critical concentration (infinite geometry) for the following homogeneous mixtures: (1) UO{sub 2}-H{sub 2}O for 3, 4, 5, 20, and 100 wt % {sup 235}U; (2) UNH for 3, 4, 5, 20, and 100 wt % {sup 235}U; (3) PuO{sub 2}-H{sub 2}O for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu); and (4) PuNH for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu). All bounding surfaces were fully reflected by 30 cm of H{sub 2}O.

  1. From Hard to Reach to How to Reach: A Systematic Review of the Literature on Hard-to-Reach Families

    ERIC Educational Resources Information Center

    Boag-Munroe, Gill; Evangelou, Maria

    2012-01-01

    This paper presents a review of the literature relating to hard-to-reach families which has been published over the last 12 years in the UK, USA, Canada and Australia. The purpose of the review was twofold: to gain insights to understandings of the term "hard-to-reach" within these services--education, health and social--which might be aiming to…

  2. Soft and Hard Adhesion Jun Young Chung

    E-print Network

    Chaudhury, Manoj K.

    's methodologies to study fouling release problems. Fouling organisms readily colonize marine vessels. One present a simple physical interpretation of the problem, which could be of value in understanding various soft elastic layers. In recent years, considerable attention has been paid to these classes of problems

  3. Converting hard copy documents for electronic dissemination

    SciTech Connect

    Hoffman, F.

    1994-12-31

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

  4. High efficiency, radiation-hard solar cells

    SciTech Connect

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

    2004-10-22

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

  5. Surface modulation of dental hard tissues

    NASA Astrophysics Data System (ADS)

    Tantbirojn, Daranee

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

  6. Reliability of hard plastic clad silica fibers

    NASA Astrophysics Data System (ADS)

    Skutnik, Bolesh J.; Spaniol, Stefan

    2006-04-01

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

  7. Earned Value-Added

    NASA Technical Reports Server (NTRS)

    Jansen, Michael

    2005-01-01

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

  8. Hard X-ray Emission Associated with White Dwarfs

    E-print Network

    I. J. Odwyer; Y. -H. Chu; R. A. Gruendl; M. A. Guerrero; R. F. Webbink

    2003-01-14

    We have used the WGACAT to search for hard X-ray sources associated with white dwarfs (WDs) from the catalog of McCook & Sion (1999). We find 17 X-ray sources coincident with WDs showing significant hard X-ray emission at energies >0.5 keV. Twelve of these WDs are in known binary systems, in two of which the accretion of the close companion's material onto the white dwarf produces the hard X-ray emission, and in the other ten of which the late-type companions' coronal activity emits hard X-rays. One WD is projected near an AGN which is responsible for the hard X-ray emission. The remaining four WDs and two additional white dwarfs with hard X-ray emission appear single. The lack of near-IR excess from the apparently single WDs suggests that either X-ray observations are more effective than near-IR photometry in diagnosing faint companions or a different emission mechanism is needed. It is intriguing that 50% of the six apparently single WDs with hard X-ray emission are among the hottest WDs. We have compared X-ray properties of 11 hot WDs with different spectral types, and conclude that stellar pulsation and fast stellar winds are not likely the origin of the hard X-ray emission, but a leakage of the high-energy Wien tail of emission from deep in the stellar atmosphere remains a tantalizing source of hard X-ray emission from hot DO and DQZO WDs. (This abstract is an abridged version.)

  9. Early expression of grain hardness in the developing wheat endosperm.

    PubMed

    Turnbull, K-M; Marion, D; Gaborit, T; Appels, R; Rahman, S

    2003-02-01

    Seeds from near-isogenic hard and soft wheat lines were harvested at regular intervals from 5 days post-anthesis to maturity and examined for hardness using the single kernel characterisation system (SKCS). SKCS analysis revealed that hard and soft lines could be distinguished from 15 days post-anthesis (dpa). This trend continued until maturity where the difference between the hard and soft lines was most marked. SKCS could not be applied to the small 5- and 10-dpa wheat kernels. Fresh developing endosperm material was examined using light microscopy and no visible differences between the cultivars were detected. When air-dried material was examined using scanning electron microscopy (SEM) differences between soft and hard lines were visible from as early as 5 dpa. Accumulation of puroindoline a and puroindoline b was investigated in developing seeds using both Western blotting and ELISA. Low levels of puroindoline a could be detected in the soft cultivar from 10 dpa, reaching a maximum at 32 dpa. In the hard cultivar, puroindoline a levels were negligible throughout grain development. Puroindoline b accumulates in both the soft and hard cultivars from 15 dpa, but overall contents were higher in the soft cultivar. These findings indicate that endosperm hardness is expressed very early in developing grain when few starch granules and storage proteins were deposited in the endosperm cells. Further, the near-isogenic soft and hard Heron lines could be differentiated by SEM at a stage in development when the accumulation of puroindolines could not be detected by the methods used in this study. PMID:12569413

  10. The noble gases: how their electronegativity and hardness determines their chemistry.

    PubMed

    Furtado, Jonathan; De Proft, Frank; Geerlings, Paul

    2015-02-26

    The establishment of an internally consistent scale of noble gas electronegativities is a long-standing problem. In the present study, the problem is attacked via the Mulliken definition, which in recent years gained widespread use to its natural appearance in the context of conceptual density functional theory. Basic ingredients of this scale are the electron affinity and the ionization potential. Whereas the latter can be computed routinely, the instability of the anion makes the judicious choice of computational technique for evaluating electron affinities much more tricky. We opted for Puiatti's approach, extrapolating the energy of high ? solvent stabilized anions to the ? = 1 (gas phase) case. The results give negative electron affinity values, monotonically increasing (except for helium which is an outlier in most of the story) to almost zero at eka-radon in agreement with high level calculations. The stability of the B3LYP results is successfully tested both via improving the level of theory (CCSD(T)) and expanding the basis set. Combined with the ionization energies (in good agreement with experiment), an electronegativity scale is obtained displaying (1) a monotonic decrease of ? when going down the periodic table, (2) top values not for the noble gases but for the halogens, as opposed to most (extrapolation) procedures of existing scales, invariably placing the noble gases on top, and (3) noble gases having electronegativities close to the chalcogens. In the accompanying hardness scale (hardly, if ever, discussed in the literature) the noble gases turn out to be by far the farthest the hardest elements, again with a continuous decrease with increasing Z. Combining ? value of the halogens and the noble gases the Ng(?+)F(?-) bond polarity emerging from ab initio calculations naturally emerges. In conclusion, the chemistry of the noble gases is for a large part determined by their extreme hardness, equivalent to a high resistance to change in its electronic population coupled to their high electronegativity. PMID:25662361

  11. value name , x integer literal

    E-print Network

    Sewell, Peter

    value name , x ident integer literal index , i , j , n, m typeconstr ::= | unit | bool | int typvar ( # , t ) M constant , c ::= | integer literal | false | true | () | (&&) | not expr , e ::= | value name | constant | expr expr # | function value name # expr bind value name in expr | let value name = expr in expr

  12. The influence of milling parameters on the material hardness in the case of magnesium alloy AZ61A

    NASA Astrophysics Data System (ADS)

    Grigora?, C. C.; Brabie, G.

    2015-11-01

    This study was conducted in order to determine the material hardness value due to modification of the milling cutting parameters. The alloy hardness was analysed as a function of different cutting parameters for milling operations (speed, feed and depth of cut), using a face mill. A total number of 17 samples were machined using parameters obtained by combining the input parameters. The total number of combinations is reduced by a preoptimization, using the DesignExpert software. The cutting process was performed in dry conditions, and it was recorded that dry cutting magnesium-aluminium alloy AZ61A with the used parameters did not lead to chip ignition. The surface hardness was determined based on the Vickers scale (HV), its values ranging from 110.59 [HV] to 121.37 [HV]. The obtained results showed that the feed has a significant contribution in the surface harness modification. The application of the Taguchi method reveals that the material hardness can be improved, together with the manufacturing time, by means of the speed, feed and depth of cut maximization.

  13. Coupling of hard dimers to dynamical lattices via random tensors

    E-print Network

    Valentin Bonzom; Harold Erbin

    2012-04-17

    We study hard dimers on dynamical lattices in arbitrary dimensions using a random tensor model. The set of lattices corresponds to triangulations of the d-sphere and is selected by the large N limit. For small enough dimer activities, the critical behavior of the continuum limit is the one of pure random lattices. We find a negative critical activity where the universality class is changed as dimers become critical, in a very similar way hard dimers exhibit a Yang-Lee singularity on planar dynamical graphs. Critical exponents are calculated exactly. An alternative description as a system of `color-sensitive hard-core dimers' on random branched polymers is provided.

  14. Algebraic Correlations of Hard Spheres in a Rectangular Box

    NASA Astrophysics Data System (ADS)

    Akaishi, Akira; Shudo, Akira

    2008-02-01

    We investigate the slow dynamics for hard-disk systems confined in the rectangular box. Phase space contains a family of marginally unstable periodic orbits, called bouncing ball orbits (BBOs), in which all particles move only in either the vertical or the horizontal direction. We derive the exponent ? = 4 for the asymptotic power law decay in the recurrence time distribution by estimating residence time around BBOs in the two hard-disk system. On the basis of a dimensionality argument, we also give the exponent as ? = N+2 for generic N hard-disk systems. Numerical calculations are in good agreement with these theoretical predictions.

  15. Cr-based bulk metallic glasses with ultrahigh hardness

    NASA Astrophysics Data System (ADS)

    Si, J. J.; Wang, T.; Wu, Y. D.; Cai, Y. H.; Chen, X. H.; Wang, W. Y.; Liu, Z. K.; Hui, X. D.

    2015-06-01

    This letter reports quaternary Cr-Co-Nb-B bulk metallic glasses (BMGs) with ultrahigh hardness and Young's moduli. Especially, Cr55Co24Nb7B14 BMG exhibits ultrahigh Vickers hardness and Young's modulus of 1605 and 278 GPa, respectively, and the highest specific Young's modulus of 37.0 × 106 N m/kg among all the developed BMGs so far. It is considered that the high hardness and Young's moduli for this kind of BMGs are intrinsically attributed to the strong interactions between metallic constituent elements and B.

  16. A Soft-Hard Combination-Based Cooperative Spectrum Sensing Scheme for Cognitive Radio Networks

    PubMed Central

    Do, Nhu Tri; An, Beongku

    2015-01-01

    In this paper we propose a soft-hard combination scheme, called SHC scheme, for cooperative spectrum sensing in cognitive radio networks. The SHC scheme deploys a cluster based network in which Likelihood Ratio Test (LRT)-based soft combination is applied at each cluster, and weighted decision fusion rule-based hard combination is utilized at the fusion center. The novelties of the SHC scheme are as follows: the structure of the SHC scheme reduces the complexity of cooperative detection which is an inherent limitation of soft combination schemes. By using the LRT, we can detect primary signals in a low signal-to-noise ratio regime (around an average of ?15 dB). In addition, the computational complexity of the LRT is reduced since we derive the closed-form expression of the probability density function of LRT value. The SHC scheme also takes into account the different effects of large scale fading on different users in the wide area network. The simulation results show that the SHC scheme not only provides the better sensing performance compared to the conventional hard combination schemes, but also reduces sensing overhead in terms of reporting time compared to the conventional soft combination scheme using the LRT. PMID:25688589

  17. Novel microwave assisted chemical synthesis of Nd?Fe??B hard magnetic nanoparticles.

    PubMed

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

    2013-04-01

    The high coercivity and excellent energy product of Nd2Fe14B hard magnets have led to a large number of high value added industrial applications. Chemical synthesis of Nd2Fe14B nanoparticles is challenging due to the large reduction potential of Nd(3+) and the high tendency for Nd2Fe14B oxidation. We report the novel synthesis of Nd2Fe14B nanoparticles by a microwave assisted combustion process. The process consisted of Nd-Fe-B mixed oxide preparation by microwave assisted combustion, followed by the reduction of the mixed oxide by CaH2. This combustion process is fast, energy efficient and offers facile elemental substitution. The coercivity of the resulting powders was ?8.0 kOe and the saturation magnetization was ?40 emu g(-1). After removal of CaO by washing, saturation magnetization increased and an energy product of 3.57 MGOe was obtained. A range of magnetic properties was obtained by varying the microwave power, reduction temperature and Nd to Fe ratio. A transition from soft to exchange coupled to hard magnetic properties was obtained by varying the composition of NdxFe1-xB8 (x varies from 7% to 40%). This synthesis procedure offers an inexpensive and facile platform to produce exchange coupled hard magnets. PMID:23426224

  18. Nonuniform liquid-crystalline phases of parallel hard rod-shaped particles: From ellipsoids to cylinders

    NASA Astrophysics Data System (ADS)

    Martínez-Ratón, Y.; Velasco, E.

    2008-08-01

    In this article we consider systems of parallel hard superellipsoids, which can be viewed as a possible interpolation between ellipsoids of revolution and cylinders. Superellipsoids are characterized by an aspect ratio and an exponent ? (shape parameter) which takes care of the geometry, with ?=1 corresponding to ellipsoids of revolution, while ?=? is the limit of cylinders. It is well known that, while hard parallel cylinders exhibit nematic, smectic, and solid phases, hard parallel ellipsoids do not stabilize the smectic phase, the nematic phase transforming directly into a solid as density is increased. We use computer simulation to find evidence that for ?>=?c, where ?c is a critical value which the simulations estimate to be approximately 1.2-1.3, the smectic phase is stabilized. This is surprisingly close to the ellipsoidal case. In addition, we use a density-functional approach, based on the Parsons-Lee approximation, to describe smectic and columnar orderings. In combination with a free-volume theory for the crystalline phase, a theoretical phase diagram is predicted. While some qualitative features, such as the enhancement of smectic stability for increasing ? and the probable absence of a stable columnar phase, are correct, the precise location of coexistence densities is quantitatively incorrect.

  19. Study of Flux Ratio of C60 to Ar Cluster Ion for Hard DLC Film deposition

    SciTech Connect

    Miyauchi, K.; Toyoda, N.; Kanda, K.; Matsui, S.; Kitagawa, T.; Yamada, I.

    2003-08-26

    To study the influence of the flux ratio of C60 molecule to Ar cluster ion on (diamond like carbon) DLC film characteristics, DLC films deposited under various flux ratios were characterized with Raman spectrometry and Near Edge X-ray Absorption Fine Structure (NEXAFS). From results of these measurements, hard DLC films were deposited when the flux ratio of C60 to Ar cluster ion was between 0.7 and 4. Furthermore the DLC film with constant sp2 content was obtained in the range of the ratio from 0.7 to 4, which contents are lower values than that of conventional films such as RF plasma. DLC films deposited under the ratio from 1 to 4 had hardness from 40 to 45GPa. It was shown that DLC films with stable properties of low sp2 content and high hardness were formed even when the fluxes were varied from 1 to 4 during deposition. It was indicated that this process was useful in the view of industrial application.

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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