New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

Science.gov (United States)

Macias, F. J.; Dahl, F.; Bruland, A.

2016-05-01

The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

On a possible test of the hard-Pomeron theory

International Nuclear Information System (INIS)

Ioffe, B.L.

1992-01-01

In the last few years there have been discussions of the fact that the Pomeron-the Regge pole responsible for high-energy scattering-has in reality a double role: a soft Pomeron built of multiperipheral hadron exchange and a hard Pomeron described by gluon exchanges in QCD. Recently, Bjorken emphasized the need to distinguish these two forms of the Pomeron. The question arises of whether it is possible to distinguish the hard and soft Pomeron experimentally. According to the hard-Pomeron concept, the hadron-hadron total cross section is determined by the imaginary part of the forward scattering amplitude corresponding to two-gluon exchange with ladder corrections. This mechanism dominates in the case of scattering of particles built from heavy quarks (a good example is γγ scattering) and also in the case of virtual-particle scattering (for example, virtual photons, where quark pairs must also be included in the ladder). These processes are hard (γ virt γ virt scattering) or impossible (γγ scattering) to observe experimentally. Bjorken suggested another process whose cross section is determined by hard-Pomeron exchange - double diffractional hadron-hadron (e.g., pp) scattering at high energies with jet production in the projectile and target fragmentation regions. If the momentum transfer from the projectile to the target is in the intermediate region, |t|∼1 GeV, and events are selected with a rapidity gap in the rapidity distribution of produced particles between the two fragmentation regions, then, according to Bjorken, a process determined by the hard Pomeron will be observed. The author addresses this proposal

Comprehensive hard materials

CERN Document Server

2014-01-01

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

7 CFR 201.57 - Hard seeds.

Science.gov (United States)

2010-01-01

... REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard at the end of the prescribed test because they have not absorbed water, due to an impermeable seed coat... percentage of germination. For flatpea, continue the swollen seed in test for 14 days when germinating at 15...

Micro-hardness of non-irradiated uranium dioxide

International Nuclear Information System (INIS)

Kim, Sung-Sik; Takagi, Osamu; Obata, Naomi; Kirihara, Tomoo.

1983-01-01

In order to obtain the optimum conditions for micro-hardness measurements of sintered UO 2 , two kinds of hardness tests (Vickers and Knoop) were examined with non-irradiated UO 2 of 2.5 and 5 μm in grain size. The hardness values were obtained as a function of the applied load in the load range of 25 -- 1,000 g. In the Vickers test, cracks were generated around the periphery of an indentation even at lower load of 50 g, which means the Vickers hardness is not suitable for UO 2 specimens. In the Knoop test, three stages of load dependence were observed for sintered pellet as well as for a single crystal by Bates. Load dependence of Knoop hardness and crack formation were discussed. In the range of applied load around 70 -- 100 g there were plateau region where hardness values were nearly unchanged and did not contain any cracks in the indentation. The plateau region represents a hardness of a specimen. From a comparison between the hardness values of 2.5 μm and those of 5 μm UO 2 , it was approved that the degree of sintering controls the hardness in the plateau region. (author)

A proposed hardness assurance test methodology for bipolar linear circuits and devices in a space ionizing radiation environment

International Nuclear Information System (INIS)

Pease, R.L.; Brown, D.B.; Cohn, L.

1997-01-01

A hardness assurance test approach has been developed for bipolar linear circuits and devices in space. It consists of a screen for dose rate sensitivity and a characterization test method to develop the conditions for a lot acceptance test at high dose rate

Large-Scale Academic Achievement Testing of Deaf and Hard-of-Hearing Students: Past, Present, and Future

Science.gov (United States)

Qi, Sen; Mitchell, Ross E.

2012-01-01

The first large-scale, nationwide academic achievement testing program using Stanford Achievement Test (Stanford) for deaf and hard-of-hearing children in the United States started in 1969. Over the past three decades, the Stanford has served as a benchmark in the field of deaf education for assessing student academic achievement. However, the…

Can joint sound assess soft and hard endpoints of the Lachman test?: A preliminary study.

Science.gov (United States)

Hattori, Koji; Ogawa, Munehiro; Tanaka, Kazunori; Matsuya, Ayako; Uematsu, Kota; Tanaka, Yasuhito

2016-05-12

The Lachman test is considered to be a reliable physical examination for anterior cruciate ligament (ACL) injury. Patients with a damaged ACL demonstrate a soft endpoint feeling. However, examiners judge the soft and hard endpoints subjectively. The purpose of our study was to confirm objective performance of the Lachman test using joint auscultation. Human and porcine knee joints were examined. Knee joint sound during the Lachman test (Lachman sound) was analyzed by fast Fourier transformation. As quantitative indices of Lachman sound, the peak sound as the maximum relative amplitude (acoustic pressure) and its frequency were used. The mean Lachman peak sound for healthy volunteer knees was 86.9 ± 12.9 Hz in frequency and -40 ± 2.5 dB in acoustic pressure. The mean Lachman peak sound for intact porcine knees was 84.1 ± 9.4 Hz and -40.5 ± 1.7 dB. Porcine knees with ACL deficiency had a soft endpoint feeling during the Lachman test. The Lachman peak sounds of porcine knees with ACL deficiency were dispersed into four distinct groups, with center frequencies of around 40, 160, 450, and 1600. The Lachman peak sound was capable of assessing soft and hard endpoints of the Lachman test objectively.

Work Hard / Play Hard

OpenAIRE

Burrows, J.; Johnson, V.; Henckel, D.

2016-01-01

Work Hard / Play Hard was a participatory performance/workshop or CPD experience hosted by interdisciplinary arts atelier WeAreCodeX, in association with AntiUniversity.org. As a socially/economically engaged arts practice, Work Hard / Play Hard challenged employees/players to get playful, or go to work. 'The game changes you, you never change the game'. Employee PLAYER A 'The faster the better.' Employer PLAYER B

Cobalt allergy in hard metal workers

Energy Technology Data Exchange (ETDEWEB)

Fischer, T; Rystedt, I

1983-03-01

Hard metal contains about 10% cobalt. 853 hard metal workers were examined and patch tested with substances from their environment. Initial patch tests with 1% cobalt chloride showed 62 positive reactions. By means of secondary serial dilution tests, allergic reactions to cobalt were reproduced in 9 men and 30 women. Weak reactions could not normally be reproduced. A history of hand eczema was found in 36 of the 39 individuals with reproducible positive test reactions to cobalt, while 21 of 23 with a positive initial patch test but negative serial dilution test had never had any skin problems. Hand etching and hand grinding, mainly female activities and traumatic to the hands, were found to involve the greatest risk of cobalt sensitization. 24 individuals had an isolated cobalt allergy. They had probably been sensitized by hard metal work, while the individuals, all women, who had simultaneous nickel allergy had probably been sensitized to nickel before their employment and then became sensitized to cobalt by hard metal work. A traumatic occupation, which causes irritant contact dermatitis and/or a previous contact allergy or atopy is probably a prerequisite for the development of cobalt allergy.

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

Directory of Open Access Journals (Sweden)

Josip Vrdoljak

2016-03-01

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

Testing the radiation hardness of lead tungstate scintillating crystals

CERN Document Server

Shao, M; Li Chuan; Chen, H; Xu, Z Z; Wang, Z M

2000-01-01

Large Hadron Collider operation will produce a high radiation background. PbWO/sub 4/ crystals are selected as scintillators for the CMS electromagnetic calorimeter. To reach the precise requirement for energy measurements, a strict requirement for the radiation hardness is needed. In this paper, we present a method for evaluating the radiation hardness and its measurement. Results for several full size (23 cm length) lead tungstate crystals under Co/sup 60/ gamma - ray irradiation are given, investigating the light yield loss and its longitudinal uniformity. (8 refs).

Hard electronics; Hard electronics

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

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

Silicon photo-multiplier radiation hardness tests with a beam controlled neutron source

International Nuclear Information System (INIS)

Angelone, M.; Pillon, M.; Faccini, R.; Pinci, D.; Baldini, W.; Calabrese, R.; Cibinetto, G.; Cotta Ramusino, A.; Malaguti, R.; Pozzati, M.

2010-01-01

Radiation hardness tests were performed at the Frascati Neutron Generator on silicon Photo-Multipliers that were made of semiconductor photon detectors built from a square matrix of avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated, integrating up to 7x10 10 1-MeV-equivalent neutrons per cm 2 . Detector performance was recorded during the neutron irradiation, and a gradual deterioration of their properties began after an integrated fluence of the order of 10 8 1-MeV-equivalent neutrons per cm 2 was reached.

Impact of aging on radiation hardness

International Nuclear Information System (INIS)

Shaneyfelt, M.R.; Winokur, P.S.; Fleetwood, D.M.

1997-01-01

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

Engineering Sensitivity Improvement of Helium Mass Spectrometer Leak Detection System by Means Global Hard Vacuum Test

International Nuclear Information System (INIS)

Sigit Asmara Santa

2006-01-01

The engineering sensitivity improvement of Helium mass spectrometer leak detection using global hard vacuum test configuration has been done. The purpose of this work is to enhance the sensitivity of the current leak detection of pressurized method (sniffer method) with the sensitivity of 10 -3 ∼ 10 -5 std cm 3 /s, to the global hard vacuum test configuration method which can be achieved of up to 10 -8 std cm 3 /s. The goal of this research and development is to obtain a Helium leak test configuration which is suitable and can be used as routine bases in the quality control tests of FPM capsule and AgInCd safety control rod products. The result is an additional instrumented vacuum tube connected with conventional Helium mass spectrometer. The pressure and temperature of the test object during the leak measurement are simulated by means of a 4.1 kW capacity heater and Helium injection to test object, respectively. The addition of auxiliary mechanical vacuum pump of 2.4 l/s pumping speed which is directly connected to the vacuum tube, will reduce 86 % of evacuation time. The reduction of the measured sensitivity due to the auxiliary mechanical vacuum pump can be overcome by shutting off the pump soon after Helium mass spectrometer reaches its operating pressure condition. (author)

Comparison of proton microbeam and gamma irradiation for the radiation hardness testing of silicon PIN diodes

Science.gov (United States)

Jakšić, M.; Grilj, V.; Skukan, N.; Majer, M.; Jung, H. K.; Kim, J. Y.; Lee, N. H.

2013-09-01

Simple and cost-effective solutions using Si PIN diodes as detectors are presently utilized in various radiation-related applications in which excessive exposure to radiation degrades their charge transport properties. One of the conventional methods for the radiation hardness testing of such devices is time-consuming irradiation with electron beam or gamma-ray irradiation facilities, high-energy proton accelerators, or with neutrons from research reactors. Recently, for the purpose of radiation hardness testing, a much faster nuclear microprobe based approach utilizing proton irradiation has been developed. To compare the two different irradiation techniques, silicon PIN diodes have been irradiated with a Co-60 gamma radiation source and with a 6 MeV proton microbeam. The signal degradation in the silicon PIN diodes for both irradiation conditions has been probed by the IBIC (ion beam induced charge) technique, which can precisely monitor changes in charge collection efficiency. The results presented are reviewed on the basis of displacement damage calculations and NIEL (non-ionizing energy loss) concept.

Characterization of the inhomogeneous constitutive properties of laser welding beams by the micro-Vickers hardness test and the rule of mixture

International Nuclear Information System (INIS)

Song, Yanli; Hua, Lin; Chu, Dongning; Lan, Jian

2012-01-01

Highlights: ► Relationship between Vickers hardness and material parameters was quantitatively built. ► Inhomogeneous weld properties were determined by hardness test combined the rule of mixture. ► Instrumented indentation tests verified these calculated properties of welds. ► Deviations between the calculated and experimental results were limited to 8.0%. -- Abstract: A novel approach has been proposed to characterize the inhomogeneous mechanical properties of weld materials by using the micro-Vickers hardness test combined with the rule of mixture. This proposed method has introduced the influences of the inhomogeneous properties of weld materials by considering the variations in plastic behaviour across the weld cross-section. The inhomogeneous properties of laser welding beams for tailor welded blanks (TWBs), which were three different types of combinations of DX56D and DP600 automotive steel sheets, were extracted by using this proposed method. The instrumented indentation tests were conducted to verify the measured inhomogeneous properties of weld materials. The fact that the calculated true stress–strain curves agreed well with the experimental ones has confirmed the reliability and accuracy of the proposed method.

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

Directory of Open Access Journals (Sweden)

Wei Sun

2015-01-01

Full Text Available Due to the material nonlinearity of hard coating, the coated structure produces the nonlinear dynamical behaviors of variable stiffness and damping, which make the modeling of hard-coating composite structure become a challenging task. In this study, the polynomial was adopted to characterize this material nonlinearity and an analytical modeling method was developed for the hard-coating composite plate. Firstly, to relate the hard-coating material parameters obtained by test and the analytical model, the expression of equivalent strain of composite plate was derived. Then, the analytical model of hard-coating composite plate was created by energy method considering the material nonlinearity of hard coating. Next, using the Newton-Raphson method to solve the vibration response and resonant frequencies of composite plate and a specific calculation procedure was also proposed. Finally, a cantilever plate coated with MgO + Al2O3 hard coating was chosen as study case; the vibration response and resonant frequencies of composite plate were calculated using the proposed method. The calculation results were compared with the experiment and general linear calculation, and the correctness of the created model was verified. The study shows the proposed method can still maintain an acceptable precision when the material nonlinearity of hard coating is stronger.

Analysis of surface hardness of artificially aged resin composites

Directory of Open Access Journals (Sweden)

Denise Cremonezzi Tornavoi

2012-02-01

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

The hardness of the hydroxyapatite-titania bilayer coatings by microindentation and nanoindentation testing

Science.gov (United States)

SIDANE, Djahida; KHIREDDINE, Hafit; YALA, Sabeha

2017-12-01

The aim of this paper is to investigate the effect of the addition of titania (TiO2) inner-layer on the morphological and mechanical properties of hydroxyapatite (HAP) bioceramic coatings deposited on 316L stainless steel (316L SS) by sol-gel method in order to improve the properties of hydroxyapatite and expand its clinical application. The addition of TiO2 as sublayer of a hydroxyapatite coating results in changes in surface morphology as well as an increase of the microhardness. The deposition of the inner-layer provides the formation of new types of hydroxyapatite coatings at the same condition of annealing. This represents an advantage for the various applications of the hydroxyapatite bioceramic in the medical field. Classical hardness measurements conducted on the coated systems under the same indentation load (10g) indicated that the microhardness of the HAP coating is improved by the addition of TiO2 inner-layer on the 316L stainless steel substrate. The hardness values obtained from both classical tests in microindentation and the continuous stiffness measurement mode in nanoindentation are slightly different. This is because nanoindentation is more sensitive to the surface roughness and the influence of defects that could be present into the material. Moreover, nanoindentation is the most useful method to separate the contribution of each layer in the bilayer coatings. In this study, the hardness is comparable with those reported previously for pure HAP ceramics (1.0-5.5 GPa) which are close to the properties of natural teeth.

Monitoring system for testing the radiation hardness of a KINTEX-7 FPGA

Energy Technology Data Exchange (ETDEWEB)

Cojocariu, L. N., E-mail: lucian.cojocariu@cern.ch [Horia Hulubei National Institute for R& D in Physics and Nuclear Engineering (Reactorului 30, MG, Romania) (Romania); Stefan cel Mare University of Suceava (Universitatii 13, Suceava, Romania) (Romania); Placinta, V. M., E-mail: vlad-mihai.placinta@cern.ch [Horia Hulubei National Institute for R& D in Physics and Nuclear Engineering (Reactorului 30, MG, Romania) (Romania); University POLITEHNICA of Bucharest (Splaiul Independentei 313, Bucharest, Romania) (Romania); Dumitru, L., E-mail: dlaur@nipne.ro [Horia Hulubei National Institute for R& D in Physics and Nuclear Engineering (Reactorului 30, MG, Romania) (Romania)

2016-03-25

A much more efficient Ring Imaging Cherenkov sub-detector system will be rebuilt in the second long shutdown of Large Hadron Collider for the LHCb experiment. Radiation-hard electronic components together with Commercial Off-The-Shelf ones will be used in the new Cherenkov photon detection system architecture. An irradiation program was foreseen to determine the radiation tolerance for the new electronic devices, including a Field Programmable Gate Array from KINTEX-7 family of XILINX. An automated test bench for online monitoring of the XC7K70T KINTEX-7 device operation in radiation conditions was designed and implemented by the LHCb Romanian group.

Sensitivity testing practice on pre-processing parameters in hard and soft coupled modeling

Directory of Open Access Journals (Sweden)

Z. Ignaszak

2010-01-01

Full Text Available This paper pays attention to the problem of practical applicability of coupled modeling with the use of hard and soft models types and necessity of adapted to that models data base possession. The data base tests results for cylindrical 30 mm diameter casting made of AlSi7Mg alloy were presented. In simulation tests that were applied the Calcosoft system with CAFE (Cellular Automaton Finite Element module. This module which belongs to „multiphysics” models enables structure prediction of complete casting with division of columnar and equiaxed crystals zones of -phase. Sensitivity tests of coupled model on the particular values parameters changing were made. On these basis it was determined the relations of CET (columnar-to-equaiaxed transition zone position influence. The example of virtual structure validation based on real structure with CET zone location and grain size was shown.

Towards Reconfigurable, Separable and Hard Real-Time Hybrid Simulation and Test Systems

Science.gov (United States)

Quartier, F.; Delatte, B.; Joubert, M.

2009-05-01

Formation flight needs several new technologies, new disciplines, new approaches and above all, more concurrent engineering by more players. One of the problems to be addressed are more complex simulation and test systems that are easy to re-configure to include parts of the target hardware and that can provide sufficient power to handle simulation cores that are requiring one to two orders of magnitude more processing power than the current technology provides. Critical technologies that are already addressed by CNES and Spacebel are study model reuse and simulator reconfigurability (Basiles), model portability (SMP2) and the federation of several simulators using HLA. Two more critical issues are addressed in ongoing R&D work by CNES and Spacebel and are covered by this paper and concern the time engineering and management. The first issue concerns separability (characterisation, identification and handling of separable subsystems) and the consequences on practical systems. Experiments on the Pleiades operational simulator have shown that adding precise simulation of instruments such as Doris and the Star Tracker can be added without significantly impacting overall performance. Improved time analysis leads to better system understanding and testability. The second issue concerns architectures for distributed hybrid simulators systems that provide hard real-time capabilities and can react with a relative time precision and jitter that is in the 10 to 50 µsecond range using mainstream PC's and mainstream Operating Systems. This opens a way to make smaller economic hardware test systems that can be reconfigured to make large hardware test systems without restarting development. Although such systems were considered next to impossible till now, distributed hard real-time systems are getting in reach when modern but mainstream electronics are used and when processor cores can be isolated and reserved for real-time cores. This requires a complete rethinking of the

Test of radiation hardness of pcCVD detectors

Energy Technology Data Exchange (ETDEWEB)

Schlemme, Steffen [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Technische Universitaet Darmstadt (Germany); Enders, Joachim [Technische Universitaet Darmstadt (Germany); Figuera, P.; Salamone, S. [LNS-INFN Catania (Italy); Fruehauf, J.; Kis, Mladen; Kratz, A.; Kurz, N.; Loechner, S.; Nociforo, Chiara; Schirru, Fabio; Szczepanczyk, B.; Traeger, M.; Visinka, R. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Musumarra, A. [LNS-INFN Catania (Italy); University of Catania (Italy)

2016-07-01

The new in-flight separator Super-FRS is under construction at the Facility for Antiproton and Ion Research (FAIR, Darmstadt). Ion rates up to 3 x 10{sup 11} {sup 238}U/spill demand an adaption of detectors to a high radiation environment. A test experiment to investigate the radiation hardness of polycrystalline diamond detectors (pcCVD) was performed at the LNS-INFN in Catania using a {sup 12}C beam at 62 MeV/u and intensities of up to 1.5 pnA. The setup consisted of pcCVD strip detectors to measure the beam profile, a single crystal diamond detector to calibrate the ionisation chamber working in current mode as a beam intensity monitor and a pcCVD sample to be irradiated. The IC used was designed for FAIR and showed a stable counting rate allowing us to calibrate and perform beam intensity measurements with it. The total measured counts on the sample were 8.25 x 10{sup 11} counts/mm{sup 2} over a period of 60 hours. Digital waveforms of the pcCVD signals were taken with an oscilloscope and analysed. The results showed no change of the pcCVD signal properties during the entire irradiation.

Ronchi test for characterization of nanofocusing optics at a hard x-ray free-electron laser.

Science.gov (United States)

Nilsson, Daniel; Uhlén, Fredrik; Holmberg, Anders; Hertz, Hans M; Schropp, Andreas; Patommel, Jens; Hoppe, Robert; Seiboth, Frank; Meier, Vivienne; Schroer, Christian G; Galtier, Eric; Nagler, Bob; Lee, Hae Ja; Vogt, Ulrich

2012-12-15

We demonstrate the use of the classical Ronchi test to characterize aberrations in focusing optics at a hard x-ray free-electron laser. A grating is placed close to the focus and the interference between the different orders after the grating is observed in the far field. Any aberrations in the beam or the optics will distort the interference fringes. The method is simple to implement and can provide single-shot information about the focusing quality. We used the Ronchi test to measure the aberrations in a nanofocusing Fresnel zone plate at the Linac Coherent Light Source at 8.194 keV.

Influence of heat treatment and indenter tip material on depth sensing hardness tests at high temperatures of fusion relevant materials

International Nuclear Information System (INIS)

Bredl, Julian; Dany, Manuel; Albinski, Bartlomiej; Schneider, Hans-Christian; Kraft, Oliver

2015-01-01

Highlights: • Operation of a custom-made indentation device designed for test temperatures up to 650 °C and a remote handled operation in a Hot Cell. • Instrumented indentation and conventional hardness testing of unirradiated MANET II and EUROFER. • Comparison of diamond and sapphire as indenter tip materials. - Abstract: The instrumented indentation is a suitable method for testing of even small neutron-irradiated specimens. From the continuously recorded indentation depth and the indentation force, it is possible to deduce mechanical parameters of the tested material. In this paper, a brief description of the high temperature device is given and representative results are presented. In the study, unirradiated steels are investigated by instrumented indentation at temperatures up to 500 °C. It is shown that the hardness is highly depending on the testing-temperature and can be correlated to the results of conventional tensile testing experiments. A not negligible influence of the indenter tip material is observed. The results show the functionality of the high-temperature indentation device.

Influence of heat treatment and indenter tip material on depth sensing hardness tests at high temperatures of fusion relevant materials

Energy Technology Data Exchange (ETDEWEB)

Bredl, Julian, E-mail: julian.bredl@kit.edu; Dany, Manuel; Albinski, Bartlomiej; Schneider, Hans-Christian; Kraft, Oliver

2015-10-15

Highlights: • Operation of a custom-made indentation device designed for test temperatures up to 650 °C and a remote handled operation in a Hot Cell. • Instrumented indentation and conventional hardness testing of unirradiated MANET II and EUROFER. • Comparison of diamond and sapphire as indenter tip materials. - Abstract: The instrumented indentation is a suitable method for testing of even small neutron-irradiated specimens. From the continuously recorded indentation depth and the indentation force, it is possible to deduce mechanical parameters of the tested material. In this paper, a brief description of the high temperature device is given and representative results are presented. In the study, unirradiated steels are investigated by instrumented indentation at temperatures up to 500 °C. It is shown that the hardness is highly depending on the testing-temperature and can be correlated to the results of conventional tensile testing experiments. A not negligible influence of the indenter tip material is observed. The results show the functionality of the high-temperature indentation device.

Radiation-Hard Quartz Cerenkov Calorimeters

International Nuclear Information System (INIS)

Akgun, U.; Onel, Y.

2006-01-01

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

Calibration of hard x-ray (15 - 50 keV) optics at the MPE test facility PANTER

Science.gov (United States)

Bräuninger, Heinrich; Burkert, Wolfgang; Hartner, Gisela D.; Citterio, Oberto; Ghigo, Mauro; Mazzoleni, Francesco; Pareschi, Giovanni; Spiga, Daniele

2004-02-01

The Max-Planck-Institut für extraterrestrische Physik (MPE) in Garching, Germany, operates the large X-ray beam line facility PANTER for testing astronomical systems. At PANTER a number of telescopes like EXOSAT, ROSAT, SAX, JET-X, ABRIXAS, XMM and SWIFT operating in the soft energy range (0.02 - 15 keV) have been successfully calibrated. In the present paper we report on an important upgrade recently implemented that enables the calibration of hard X-ray optics (from 15 up to 50 keV). Currently hard X-ray optics based on single and multilayer coating are being developed for several future X-ray missions. The hard X-ray calibrations at PANTER are carried out by a high energy source based on an electron gun and several anodes, able to cover the energy range from 4.5 up to 50 keV. It provides fluxes up to 104 counts/sec/cm2 at the instrument chamber with a stability better than 1%. As detector a pn-CCD camera operating between 0.2 and 50 keV and a collecting area of 36 cm2 is used. Taking into account the high energy resolution of the CCD (145 eV at 6 keV), a very easy way to operate the facility in hard X-ray is in energy-dispersive mode (i.e. with a broad-band beam). A double crystal monochromator is also available providing energies up to 20 keV. In this paper we present the first results obtained by using PANTER for hard X-ray characterizations, performed on prototype multilayer optics developed by the Osservatorio Astronomico di Brera (OAB), Milano, Italy, and the Harvard-Smithsonian Center for Astrophysics (CfA), Cambridge, MA, USA.

Design and Tests of the Hard X-ray Polarimeter X-Calibur

Directory of Open Access Journals (Sweden)

M. Beilicke

2014-12-01

Full Text Available X-ray polarimetry promises to give qualitatively new information bout high-energy astrophysical sources, such as binary black hole  systems, micro-quasars, active galactic nuclei, and gamma-ray bursts. We designed, built and tested ahard X-ray polarimeter, X-Calibur, to be used in the focal plane of the InFOCuS grazing incidence hard X-ray telescope.X-Calibur combines a low-Z Compton scatterer with a CZT detector assembly to measure the polarization of 20−60 keV X-rays making use of the fact that polarized photons Compton scatter preferentially perpendicular to the electric field orientation; in principal, a similar space-borne experiment could be operated in the 5−100 keV regime. X-Calibur achieves a high detection efficiency of order unity.

Radiation hardness tests of piezoelectric actuators with fast neutrons at liquid helium temperature

Energy Technology Data Exchange (ETDEWEB)

Fouaidy, M.; Martinet, G.; Hammoudi, N.; Chatelet, F.; Olivier, A.; Blivet, S.; Galet, F. [CNRS-IN2P3-IPN Orsay, Orsay (France)

2007-07-01

Piezoelectric actuators, which are integrated into the cold tuning system and used to compensate the small mechanical deformations of the cavity wall induced by Lorentz forces due to the high electromagnetic surface field, may be located in the radiation environment during particle accelerator operation. In order to provide for a reliable operation of the accelerator, the performance and life time of piezoelectric actuators ({approx}24.000 units for ILC) should not show any significant degradation for long periods (i.e. machine life duration: {approx}20 years), even when subjected to intense radiation (i.e. gamma rays and fast neutrons). An experimental program, aimed at investigating the effect of fast neutrons radiation on the characteristics of piezoelectric actuators at liquid helium temperature (i.e. T{approx}4.2 K), was proposed for the working package WPNo.8 devoted to tuners development in the frame of CARE project. A neutrons irradiation facility, already installed at the CERI cyclotron located at Orleans (France), was upgraded and adapted for actuators irradiations tests purpose. A deuterons beam (maximum energy and beam current: 25 MeV and 35{mu}A) collides with a thin (thickness: 3 mm) beryllium target producing a high neutrons flux with low gamma dose ({approx}20%): a neutrons fluence of more than 10{sup 14} n/cm{sup 2} is achieved in {approx}20 hours of exposure. A dedicated cryostat was developed at IPN Orsay and used previously for radiation hardness test of calibrated cryogenic thermometers and pressure transducers used in LHC superconducting magnets. This cryostat could be operated either with liquid helium or liquid argon. This irradiation facility was upgraded for allowing fast turn-over of experiments and a dedicated experimental set-up was designed, fabricated, installed at CERI and successfully operated for radiation hardness tests of several piezoelectric actuators at T{approx}4.2 K. This new apparatus allows on-line automatic measurements

Radiation hardness tests of piezoelectric actuators with fast neutrons at liquid helium temperature

International Nuclear Information System (INIS)

Fouaidy, M.; Martinet, G.; Hammoudi, N.; Chatelet, F.; Olivier, A.; Blivet, S.; Galet, F.

2007-01-01

Piezoelectric actuators, which are integrated into the cold tuning system and used to compensate the small mechanical deformations of the cavity wall induced by Lorentz forces due to the high electromagnetic surface field, may be located in the radiation environment during particle accelerator operation. In order to provide for a reliable operation of the accelerator, the performance and life time of piezoelectric actuators (∼24.000 units for ILC) should not show any significant degradation for long periods (i.e. machine life duration: ∼20 years), even when subjected to intense radiation (i.e. gamma rays and fast neutrons). An experimental program, aimed at investigating the effect of fast neutrons radiation on the characteristics of piezoelectric actuators at liquid helium temperature (i.e. T∼4.2 K), was proposed for the working package WPNo.8 devoted to tuners development in the frame of CARE project. A neutrons irradiation facility, already installed at the CERI cyclotron located at Orleans (France), was upgraded and adapted for actuators irradiations tests purpose. A deuterons beam (maximum energy and beam current: 25 MeV and 35μA) collides with a thin (thickness: 3 mm) beryllium target producing a high neutrons flux with low gamma dose (∼20%): a neutrons fluence of more than 10 14 n/cm 2 is achieved in ∼20 hours of exposure. A dedicated cryostat was developed at IPN Orsay and used previously for radiation hardness test of calibrated cryogenic thermometers and pressure transducers used in LHC superconducting magnets. This cryostat could be operated either with liquid helium or liquid argon. This irradiation facility was upgraded for allowing fast turn-over of experiments and a dedicated experimental set-up was designed, fabricated, installed at CERI and successfully operated for radiation hardness tests of several piezoelectric actuators at T∼4.2 K. This new apparatus allows on-line automatic measurements of actuators characteristics and the

A study on hardness behavior of geopolymer paste in different condition

Science.gov (United States)

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

2016-07-01

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

Thermal spray coatings replace hard chrome

International Nuclear Information System (INIS)

Schroeder, M.; Unger, R.

1997-01-01

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

Hardness of enamel exposed to Coca-Cola and artificial saliva.

Science.gov (United States)

Devlin, H; Bassiouny, M A; Boston, D

2006-01-01

The purpose of this study was to determine the rate of change in indentation hardness of enamel in permanent teeth exposed to Coca-Cola. In a further experiment, the ability of a commercially available artificial saliva to remineralize enamel treated with Coca-Cola was tested. Ten enamel specimens were randomly chosen to be treated with Coca-Cola (experimental groups) and seven with water (control group). The fluids were applied for 1, 2, 3 h and overnight (15 h), washed off with a few drops of water and the moist enamel indentation hardness tested after each interval. With Coca-Cola treatment, the mean enamel hardness was 92.6% (s.d. = 7.9) of the original baseline hardness after 1 h, 93.25% (s.d. = 10.15) after 2 h, 85.7% (s.d. = 12.03) after 3 h and 80.3% after 15 h. The mean indentation hardness of control specimens treated with water was 108.7% (s.d. = 16.09) of the original hardness after 1 h, 99.09% (s.d. = 18.98) after 2 h, 98.97% (s.d. =11.24) after 3 h and 98.42% (s.d. = 22.78) after 15 h. In a separate experiment, the hardness of 9 enamel specimens was tested, as previously described, before and after treatment with Coca-Cola overnight and again after application of artificial saliva for 3 min. Coca-Cola reduced the mean indentation hardness of enamel in the teeth, but the hardness was partially restored with artificial saliva (Salivart) and increased by 18% from the demineralized enamel hardness.

Crash Testing and Simulation of a Cessna 172 Aircraft: Hard Landing Onto Concrete

Science.gov (United States)

Jackson, Karen E.; Fasanella, Edwin L.

2016-01-01

A full-scale crash test of a Cessna 172 aircraft was conducted at the Landing and Impact Research Facility at NASA Langley Research Center during the summer of 2015. The purpose of the test was to evaluate the performance of Emergency Locator Transmitters (ELTs) that were mounted at various locations in the aircraft and to generate impact test data for model validation. A finite element model of the aircraft was developed for execution in LSDYNA to simulate the test. Measured impact conditions were 722.4-in/s forward velocity and 276-in/s vertical velocity with a 1.5deg pitch (nose up) attitude. These conditions were intended to represent a survivable hard landing. The impact surface was concrete. During the test, the nose gear tire impacted the concrete, followed closely by impact of the main gear tires. The main landing gear spread outward, as the nose gear stroked vertically. The only fuselage contact with the impact surface was a slight impact of the rearmost portion of the lower tail. Thus, capturing the behavior of the nose and main landing gear was essential to accurately predict the response. This paper describes the model development and presents test-analysis comparisons in three categories: inertial properties, time sequence of events, and acceleration and velocity time-histories.

Evaluation of dynamic characteristics of hard rock based on numerical simulations of in situ rock tests

International Nuclear Information System (INIS)

Yamagami, Yuya; Ikusada, Koji; Jiang, Yujing

2009-01-01

In situ rock tests of hard rock of conglomerate in which discontinuities in high angle are dominant were conducted. In this study, in order to confirm the validity of the test results and the test condition, and in order to elucidate the deformation behaviour and the mechanism of shear strength of the rock mass, the numerical simulations of the in situ rock tests by using distinct element method were performed. As a result, it was clarified that the behaviour of the rock mass strongly depends on both geometrical distribution of discontinuities and those mechanical properties. It is thought that a series of evaluation processes showed in this study contribute to improve the reliability of the dynamic characteristic evaluation of the rock mass. (author)

Development of radiation hard components for remote maintenance

International Nuclear Information System (INIS)

Oka, Kiyoshi; Obara, Kenjiro; Kakudate, Satoshi; Tominaga, Ryuichiro; Akada, Tamio; Morita, Hirosuke.

1997-01-01

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

Development of radiation hardness components for ITER remote maintenance

Energy Technology Data Exchange (ETDEWEB)

Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; Ito, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yagi, Toshiaki; Morita, Yousuke

1998-04-01

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

Development of radiation hardness components for ITER remote maintenance

International Nuclear Information System (INIS)

Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; Ito, Akira; Yagi, Toshiaki; Morita, Yousuke

1998-01-01

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

Revisiting the definition of local hardness and hardness kernel.

Science.gov (United States)

Polanco-Ramírez, Carlos A; Franco-Pérez, Marco; Carmona-Espíndola, Javier; Gázquez, José L; Ayers, Paul W

2017-05-17

An analysis of the hardness kernel and local hardness is performed to propose new definitions for these quantities that follow a similar pattern to the one that characterizes the quantities associated with softness, that is, we have derived new definitions for which the integral of the hardness kernel over the whole space of one of the variables leads to local hardness, and the integral of local hardness over the whole space leads to global hardness. A basic aspect of the present approach is that global hardness keeps its identity as the second derivative of energy with respect to the number of electrons. Local hardness thus obtained depends on the first and second derivatives of energy and electron density with respect to the number of electrons. When these derivatives are approximated by a smooth quadratic interpolation of energy, the expression for local hardness reduces to the one intuitively proposed by Meneses, Tiznado, Contreras and Fuentealba. However, when one combines the first directional derivatives with smooth second derivatives one finds additional terms that allow one to differentiate local hardness for electrophilic attack from the one for nucleophilic attack. Numerical results related to electrophilic attacks on substituted pyridines, substituted benzenes and substituted ethenes are presented to show the overall performance of the new definition.

Novel platens to measure the hardness of a pentagonal shaped tablet.

Science.gov (United States)

Malladi, Jaya; Sidik, Kurex; Wu, Sutan; McCann, Ryan; Dougherty, Jeffrey; Parab, Prakash; Carragher, Thomas

2017-03-01

Tablet hardness, a measure of the breaking force of a tablet, is based on numerous factors. These include the shape of the tablet and the mode of the application of force. For instance, when a pentagonal-shaped tablet was tested with a traditional hardness tester with flat platens, there was a large variation in hardness measurements. This was due to the propensity of vertices of the tablet to crush, referred to as an "improper break". This article describes a novel approach to measure the hardness of pentagonal-shaped tablets using modified platens. The modified platens have more uniform loading than flat platens. This is because they reduce loading on the vertex of the pentagon and apply forces on tablet edges to generate reproducible tablet fracture. The robustness of modified platens was assessed using a series of studies, which included feasibility and Gauge Repeatability & Reproducibility (R&R) studies. A key finding was that improper breaks, generated frequently with a traditional hardness tester using flat platens, were eliminated. The Gauge R&R study revealed that the tablets tested with novel platens generated consistent values in hardness measurements, independent of batch, hardness level, and day of testing, operator and tablet dosage strength.

A first-principles approach to total-dose hardness assurance

International Nuclear Information System (INIS)

Fleetwood, D.M.

1995-01-01

A first-principles approach to radiation hardness assurance was described that provides the technical background to the present US and European total-dose radiation hardness assurance test methods for MOS technologies, TM 1019.4 and BS 22900. These test methods could not have been developed otherwise, as their existence depends not on a wealth of empirical comparisons of IC data from ground and space testing, but on a fundamental understanding of MOS defect growth and annealing processes. Rebound testing should become less of a problem for advanced MOS small-signal electronics technologies for systems with total dose requirements below 50--100 krad(SiO 2 ) because of trends toward much thinner gate oxides. For older technologies with thicker gate oxides and for power devices, rebound testing is unavoidable without detailed characterization studies to assess the impact of interface traps on devices response in space. The QML approach is promising for future hardened technologies. A sufficient understanding of process effects on radiation hardness has been developed that should be able to reduce testing costs in the future for hardened parts. Finally, it is hoped that the above discussions have demonstrated that the foundation for cost-effective hardness assurance tests is laid with studies of the basic mechanisms of radiation effects. Without a diligent assessment of new radiation effects mechanisms in future technologies, one cannot be assured that the present generation of radiation test standards will continue to apply

Radiation hardness tests of SiPMs for the JLab Hall D Barrel calorimeter

International Nuclear Information System (INIS)

Qiang, Yi; Zorn, Carl; Barbosa, Fernando; Smith, Elton

2013-01-01

We report on the measurement of the neutron radiation hardness of silicon photomultipliers (SiPMs) manufactured by Hamamatsu Corporation in Japan and SensL in Ireland. Samples from both companies were irradiated by neutrons created by a 1 GeV electron beam hitting a thin lead target at Jefferson Lab Hall A. More tests regarding the temperature dependence of the neutron radiation damage and self-annealing were performed on Hamamatsu SiPMs using a calibrated Am–Be neutron source from the Jefferson Lab Radiation Control group. As the result of irradiation both dark current and dark rate increase linearly as a function of the 1 MeV equivalent neutron fluence and a temperature dependent self-annealing effect is observed.

Assessment of surface hardness of acrylic resins submitted to accelerated artificial aging.

Science.gov (United States)

Tornavoi, D C; Agnelli, J A M; Lepri, C P; Mazzetto, M O; Botelho, A L; Soares, R G; Dos Reis, A C

2012-06-01

The aim of this study was to assess the influence of accelerated artificial aging (AAA) on the surface hardness of acrylic resins. The following three commercial brands of acrylic resins were tested: Vipi Flash (autopolymerized resin), Vipi Wave (microwave heat-polymerized resin) and Vipi Cril (conventional heat-polymerized resin). To perform the tests, 21 test specimens (65x10x3 mm) were made, 7 for each resin. Three surface hardness readings were performed for each test specimen, before and after AAA, and the means were submitted to the following tests: Kolmogorov-Smirnov (P>0.05), Levene Statistic, Two-way ANOVA, Tukey Post Hoc (Paging, the autopolymerized acrylic resin Vipi Flash showed lower hardness values when compared with the heat-polymerized resin Vipi Cril (P=0.001). After aging, the 3 materials showed similar performance when compared among them. The Vipi Cril was the only one affected by AAA and showed lower hardness values after this procedure (Pp=0.003). It may be concluded that accelerated artificial aging influenced surface hardness of heat-polymerized acrylic resin Vipi Cril.

Hard Electromagnetic Processes

International Nuclear Information System (INIS)

Richard, F.

1987-09-01

Among hard electromagnetic processes, I will use the most recent data and focus on quantitative test of QCD. More specifically, I will retain two items: - hadroproduction of direct photons, - Drell-Yan. In addition, I will briefly discuss a recent analysis of ISR data obtained with AFS (Axial Field Spectrometer) which sheds a new light on the e/π puzzle at low P T

Microindentation hardness evaluation of iridium alloy clad vent set cups

International Nuclear Information System (INIS)

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

1993-01-01

An iridium alloy, DOP-26, is used as cladding for 238 PuO 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

Microindentation hardness evaluation of iridium alloy clad vent set cups

International Nuclear Information System (INIS)

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

1992-01-01

An iridium alloy, DOP-26, is used as cladding for 238 PuO 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

Estimation of hardness and compressive strength of SP 100 aluminum powder epoxy

Energy Technology Data Exchange (ETDEWEB)

Han, Jeong Young [Pusan National Univ., Busan (Korea, Republic of); Kim, Myung Hun [Korea Institute of Footwear and Leather Technology, Busan (Korea, Republic of); Kang, Sung Soo [Jeonju Univ., Jeonju (Korea, Republic of)

2012-09-15

In this study, we performed experimental tests on five SP 100 aluminum powder epoxy specimens with several after curing conditions in order to estimate their hardness with temperature and compressive strength. In the surface hardness test, it was found that the higher the after curing temperature, the higher was the hardness. In particular, it was found that the hardness of the specimens in cases 3 and 4 was much higher than in the other cases. In addition, in the compression tests carried out to evaluate the compressive strength, it was found that the specimens showed relatively similar stiffness and strength with after curing, and specimens with no after curing showed compression stress strain curves similar to those of thermoplastic resins.

Estimation of hardness and compressive strength of SP 100 aluminum powder epoxy

International Nuclear Information System (INIS)

Han, Jeong Young; Kim, Myung Hun; Kang, Sung Soo

2012-01-01

In this study, we performed experimental tests on five SP 100 aluminum powder epoxy specimens with several after curing conditions in order to estimate their hardness with temperature and compressive strength. In the surface hardness test, it was found that the higher the after curing temperature, the higher was the hardness. In particular, it was found that the hardness of the specimens in cases 3 and 4 was much higher than in the other cases. In addition, in the compression tests carried out to evaluate the compressive strength, it was found that the specimens showed relatively similar stiffness and strength with after curing, and specimens with no after curing showed compression stress strain curves similar to those of thermoplastic resins

Influences of pretreatment and hard baking on the mechanical reliability of SU-8 microstructures

International Nuclear Information System (INIS)

Morikaku, Toshiyuki; Kaibara, Yoshinori; Inoue, Shozo; Namazu, Takahiro; Inoue, Masatoshi; Miura, Takuya; Suzuki, Takaaki; Oohira, Fumikazu

2013-01-01

In this paper, the influences of pretreatment and hard baking on the mechanical characteristics of SU-8 microstructures are described. Four types of samples with different combinations of O 2 plasma ashing, primer coating and hard baking were prepared for shear strength tests and uniaxial tensile tests. Specially developed shear test equipment was used to experimentally measure the shear adhesion strength of SU-8 micro posts on a glass substrate. The adhesiveness was strengthened by hard baking at 200 °C for 60 min, whereas other pretreatment processes hardly affected the strength. The pretreatment and hard baking effects on the adhesive strength were compared with those on the fracture strength measured by uniaxial tensile testing. There were no influences of O 2 plasma ashing on both the strengths, and primer coating affected only tensile strength. The primer coating effect as well as the hard baking effect on stress relaxation phenomena in uniaxial tension was observed as well. Fourier transform infrared spectroscopy demonstrated that surface degradation and epoxide-ring opening polymerization would have given rise to the primer coating effect and the hard baking effect on the mechanical characteristics, respectively. (paper)

Influences of pretreatment and hard baking on the mechanical reliability of SU-8 microstructures

Science.gov (United States)

Morikaku, Toshiyuki; Kaibara, Yoshinori; Inoue, Masatoshi; Miura, Takuya; Suzuki, Takaaki; Oohira, Fumikazu; Inoue, Shozo; Namazu, Takahiro

2013-10-01

In this paper, the influences of pretreatment and hard baking on the mechanical characteristics of SU-8 microstructures are described. Four types of samples with different combinations of O2 plasma ashing, primer coating and hard baking were prepared for shear strength tests and uniaxial tensile tests. Specially developed shear test equipment was used to experimentally measure the shear adhesion strength of SU-8 micro posts on a glass substrate. The adhesiveness was strengthened by hard baking at 200 °C for 60 min, whereas other pretreatment processes hardly affected the strength. The pretreatment and hard baking effects on the adhesive strength were compared with those on the fracture strength measured by uniaxial tensile testing. There were no influences of O2 plasma ashing on both the strengths, and primer coating affected only tensile strength. The primer coating effect as well as the hard baking effect on stress relaxation phenomena in uniaxial tension was observed as well. Fourier transform infrared spectroscopy demonstrated that surface degradation and epoxide-ring opening polymerization would have given rise to the primer coating effect and the hard baking effect on the mechanical characteristics, respectively.

FEM Modeling of the Relationship between the High-Temperature Hardness and High-Temperature, Quasi-Static Compression Experiment.

Science.gov (United States)

Zhang, Tao; Jiang, Feng; Yan, Lan; Xu, Xipeng

2017-12-26

The high-temperature hardness test has a wide range of applications, but lacks test standards. The purpose of this study is to develop a finite element method (FEM) model of the relationship between the high-temperature hardness and high-temperature, quasi-static compression experiment, which is a mature test technology with test standards. A high-temperature, quasi-static compression test and a high-temperature hardness test were carried out. The relationship between the high-temperature, quasi-static compression test results and the high-temperature hardness test results was built by the development of a high-temperature indentation finite element (FE) simulation. The simulated and experimental results of high-temperature hardness have been compared, verifying the accuracy of the high-temperature indentation FE simulation.The simulated results show that the high temperature hardness basically does not change with the change of load when the pile-up of material during indentation is ignored. The simulated and experimental results show that the decrease in hardness and thermal softening are consistent. The strain and stress of indentation were analyzed from the simulated contour. It was found that the strain increases with the increase of the test temperature, and the stress decreases with the increase of the test temperature.

FEM Modeling of the Relationship between the High-Temperature Hardness and High-Temperature, Quasi-Static Compression Experiment

Directory of Open Access Journals (Sweden)

Tao Zhang

2017-12-01

Full Text Available The high-temperature hardness test has a wide range of applications, but lacks test standards. The purpose of this study is to develop a finite element method (FEM model of the relationship between the high-temperature hardness and high-temperature, quasi-static compression experiment, which is a mature test technology with test standards. A high-temperature, quasi-static compression test and a high-temperature hardness test were carried out. The relationship between the high-temperature, quasi-static compression test results and the high-temperature hardness test results was built by the development of a high-temperature indentation finite element (FE simulation. The simulated and experimental results of high-temperature hardness have been compared, verifying the accuracy of the high-temperature indentation FE simulation.The simulated results show that the high temperature hardness basically does not change with the change of load when the pile-up of material during indentation is ignored. The simulated and experimental results show that the decrease in hardness and thermal softening are consistent. The strain and stress of indentation were analyzed from the simulated contour. It was found that the strain increases with the increase of the test temperature, and the stress decreases with the increase of the test temperature.

Seismic signals hard clipping overcoming

Science.gov (United States)

Olszowa, Paula; Sokolowski, Jakub

2018-01-01

In signal processing the clipping is understand as the phenomenon of limiting the signal beyond certain threshold. It is often related to overloading of a sensor. Two particular types of clipping are being recognized: soft and hard. Beyond the limiting value soft clipping reduces the signal real gain while the hard clipping stiffly sets the signal values at the limit. In both cases certain amount of signal information is lost. Obviously if one possess the model which describes the considered signal and the threshold value (which might be slightly more difficult to obtain in the soft clipping case), the attempt of restoring the signal can be made. Commonly it is assumed that the seismic signals take form of an impulse response of some specific system. This may lead to belief that the sine wave may be the most appropriate to fit in the clipping period. However, this should be tested. In this paper the possibility of overcoming the hard clipping in seismic signals originating from a geoseismic station belonging to an underground mine is considered. A set of raw signals will be hard-clipped manually and then couple different functions will be fitted and compared in terms of least squares. The results will be then analysed.

Fabrication and installment of the hard-wired I and C works for the neutral beam injection test stand of the K-STAR project

International Nuclear Information System (INIS)

Jung, Ki Sok; Oh, Byung Hun

2004-12-01

Instrumentation and Control(I and C) of the neutral beam injection test stand (NBI-TS) for the K-STAR national fusion research project has been underway since the start of the project to answer the diverse requests arising from the various facets of the development and construction phases of the project. In a parallel effort with the software oriented I and C development, there has been existing an enormous amount of hard-wiring I and C works for the NBI facility to be developed and fabricated in schedule. Circuits and hardwired functions have been designed, tested, fabricated, and finally installed to the relevant parts of the system. Examples of those hard-wired I and C works are related to the vacuum system, gas feeding system, arc detector circuit, ion source monitoring, bending magnet and calorimeter. Another one to be mentioned is the interlock circuitry. One of the interlock circuits are related to the coolant flow failure. The other is the interlock circuit related to the vacuum failure. All of the above mentioned circuitry now constitutes integral parts for the proper operation of the NBI system; details of those hard-wired I and C work are described in this report

Applications of NTNU/SINTEF Drillability Indices in Hard Rock Tunneling

Science.gov (United States)

Zare, S.; Bruland, A.

2013-01-01

Drillability indices, i.e., the Drilling Rate Index™ (DRI), Bit Wear Index™ (BWI), Cutter Life Index™ (CLI), and Vickers Hardness Number Rock (VHNR), are indirect measures of rock drillability. These indices are recognized as providing practical characterization of rock properties used in the Norwegian University of Science and Technology (NTNU) time and cost prediction models available for hard rock tunneling and surface excavation. The tests form the foundation of various hard rock equipment capacity and performance prediction methods. In this paper, application of the tests for tunnel boring machine (TBM) and drill and blast (D&B) tunneling is investigated and the impact of the indices on excavation time and costs is presented.

Comprehension of Written Grammar Test: Reliability and Known-Groups Validity Study with Hearing and Deaf and Hard-of-Hearing Students

Science.gov (United States)

Cannon, Joanna E.; Hubley, Anita M.; Millhoff, Courtney; Mazlouman, Shahla

2016-01-01

The aim of the current study was to gather validation evidence for the "Comprehension of Written Grammar" (CWG; Easterbrooks, 2010) receptive test of 26 grammatical structures of English print for use with children who are deaf and hard of hearing (DHH). Reliability and validity data were collected for 98 participants (49 DHH and 49…

Novel hard compositions and methods of preparation

Science.gov (United States)

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.

Hard coatings

International Nuclear Information System (INIS)

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

1993-01-01

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

Novel Aspects of Hard Diffraction in QCD

International Nuclear Information System (INIS)

Brodsky, Stanley J.

2005-01-01

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

The effect of an electronic "hard-stop" alert on HIV testing rates in the emergency department.

Science.gov (United States)

Schnall, Rebecca; Sperling, Jeremy D; Liu, Nan; Green, Robert A; Clark, Sunday; Vawdrey, David K

2013-01-01

Use of electronic alerts in clinical practice has had mixed effects on providers' prescribing practices. Little research has explored the use of electronic alerts for improving screening practices. New York City has one of the highest rates of HIV in the United States. Recent New York State legislation requires healthcare providers to offer an HIV test to patients aged 13-64 years during a clinical encounter. Adhering to this requirement is particularly challenging in emergency department (ED) settings, which are frequently overcrowded and under-resourced. The purpose of this study was to evaluate the effect of an electronic "hard-stop" alert on HIV testing rates in the ED. Approximately four months of data were reviewed before and after the implementation of the alert. We found that use of the electronic alert significantly increased documentation of offering an HIV test (O.R. = 267.27, p<0.001) and resulted in a significant increase in HIV testing. Findings from this study add to the current knowledge about the use of electronic alertsfor improving disease screening.

Radiation Hardness tests with neutron flux on different Silicon photomultiplier devices

Science.gov (United States)

Cattaneo, P. W.; Cervi, T.; Menegolli, A.; Oddone, M.; Prata, M.; Prata, M. C.; Rossella, M.

2017-07-01

Radiation hardness is an important requirement for solid state readout devices operating in high radiation environments common in particle physics experiments. The MEG II experiment, at PSI, Switzerland, investigates the forbidden decay μ+ → e+ γ. Exploiting the most intense muon beam of the world. A significant flux of non-thermal neutrons (kinetic energy Ek>= 0.5 MeV) is present in the experimental hall produced along the beam-line and in the hall itself. We present the effects of neutron fluxes comparable to the MEG II expected doses on several Silicon Photomultiplier (SiPMs). The tested models are: AdvanSiD ASD-NUV3S-P50 (used in MEG II experiment), AdvanSiD ASD-NUV3S-P40, AdvanSiD ASD-RGB3S-P40, Hamamatsu and Excelitas C30742-33-050-X. The neutron source is the thermal Sub-critical Multiplication complex (SM1) moderated with water, located at the University of Pavia (Italy). We report the change of SiPMs most important electric parameters: dark current, dark pulse frequency, gain, direct bias resistance, as a function of the integrated neutron fluency.

Life evaluation of FR-CV cable on thermal-radiation combined aging by micro-hardness

International Nuclear Information System (INIS)

Sugiyama, Masahiko; Ogata, Akimasa; Nitta, Makoto; Tani, Tsuneo; Yagi, Toshiaki; Seguchi, Tadao.

1996-01-01

For the evaluation of cable life for the application to nuclear facilities, the accelerated test was conducted by the combination of radiation and thermal oxidation. The degradation of FR-CV cable by the aging was monitored by tensile test, micro-hardness test, and gel-fraction measurement. The micro-hardness increased with the progress of degradation and related well with decrease of ultimate elongation of the sheath material, and was also reflected by the loss of plasticizer. The micro-hardness technique has a possibility to detect the degradation of cable as a non-destructive detector. (author)

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

Science.gov (United States)

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

2013-01-01

Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker's hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey's test and binary comparisons by t-test with a significance level of P = 0.05. Results: The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (P composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites. PMID:24966724

Bond-orientational analysis of hard-disk and hard-sphere structures.

Science.gov (United States)

Senthil Kumar, V; Kumaran, V

2006-05-28

We report the bond-orientational analysis results for the thermodynamic, random, and homogeneously sheared inelastic structures of hard-disks and hard-spheres. The thermodynamic structures show a sharp rise in the order across the freezing transition. The random structures show the absence of crystallization. The homogeneously sheared structures get ordered at a packing fraction higher than the thermodynamic freezing packing fraction, due to the suppression of crystal nucleation. On shear ordering, strings of close-packed hard-disks in two dimensions and close-packed layers of hard-spheres in three dimensions, oriented along the velocity direction, slide past each other. Such a flow creates a considerable amount of fourfold order in two dimensions and body-centered-tetragonal (bct) structure in three dimensions. These transitions are the flow analogs of the martensitic transformations occurring in metals due to the stresses induced by a rapid quench. In hard-disk structures, using the bond-orientational analysis we show the presence of fourfold order. In sheared inelastic hard-sphere structures, even though the global bond-orientational analysis shows that the system is highly ordered, a third-order rotational invariant analysis shows that only about 40% of the spheres have face-centered-cubic (fcc) order, even in the dense and near-elastic limits, clearly indicating the coexistence of multiple crystalline orders. When layers of close-packed spheres slide past each other, in addition to the bct structure, the hexagonal-close-packed (hcp) structure is formed due to the random stacking faults. Using the Honeycutt-Andersen pair analysis and an analysis based on the 14-faceted polyhedra having six quadrilateral and eight hexagonal faces, we show the presence of bct and hcp signatures in shear ordered inelastic hard-spheres. Thus, our analysis shows that the dense sheared inelastic hard-spheres have a mixture of fcc, bct, and hcp structures.

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

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

Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

International Nuclear Information System (INIS)

Cuss, R.J.; Harrington, J.F.; Noy, D.J.

2010-02-01

This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

Energy Technology Data Exchange (ETDEWEB)

Cuss, R.J.; Harrington, J.F.; Noy, D.J. (British Geological Survey (United Kingdom))

2010-02-15

This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

Sorption of radionuclides on hard rocks

International Nuclear Information System (INIS)

Berry, J.A.; Bourke, P.J.; Green, A.; Littleboy, A.K.

1987-09-01

Methods for measuring sorption on hard rocks, particularly of strontium, caesium, neptunium and americium on Darley Dale sandstone and Welsh slate have been investigated. The methods tried included batch tests with crushed rock and tests of simultaneous diffusion and convection with sorption on intact rock. High pressures (800m H 2 O) were used in the convective tests to pump water quickly through the rock samples and to measure high sorptivities in times shorter than those needed in the diffusive methods with intact samples. (author)

Why Are Drugs So Hard to Quit?

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Full Text Available ... in your brain and makes it hard to feel OK without the drug. This video from NIDA ... Advertise Developers +YouTube Terms Privacy Policy & Safety Send feedback Test new features Loading... Working... Sign in to ...

Theoretical Conversions of Different Hardness and Tensile Strength for Ductile Materials Based on Stress-Strain Curves

Science.gov (United States)

Chen, Hui; Cai, Li-Xun

2018-04-01

Based on the power-law stress-strain relation and equivalent energy principle, theoretical equations for converting between Brinell hardness (HB), Rockwell hardness (HR), and Vickers hardness (HV) were established. Combining the pre-existing relation between the tensile strength ( σ b ) and Hollomon parameters ( K, N), theoretical conversions between hardness (HB/HR/HV) and tensile strength ( σ b ) were obtained as well. In addition, to confirm the pre-existing σ b -( K, N) relation, a large number of uniaxial tensile tests were conducted in various ductile materials. Finally, to verify the theoretical conversions, plenty of statistical data listed in ASTM and ISO standards were adopted to test the robustness of the converting equations with various hardness and tensile strength. The results show that both hardness conversions and hardness-strength conversions calculated from the theoretical equations accord well with the standard data.

A new, bright and hard aluminum surface produced by anodization

Science.gov (United States)

Hou, Fengyan; Hu, Bo; Tay, See Leng; Wang, Yuxin; Xiong, Chao; Gao, Wei

2017-07-01

Anodized aluminum (Al) and Al alloys have a wide range of applications. However, certain anodized finishings have relatively low hardness, dull appearance and/or poor corrosion resistance, which limited their applications. In this research, Al was first electropolished in a phosphoric acid-based solution, then anodized in a sulfuric acid-based solution under controlled processing parameters. The anodized specimen was then sealed by two-step sealing method. A systematic study including microstructure, surface morphology, hardness and corrosion resistance of these anodized films has been conducted. Results show that the hardness of this new anodized film was increased by a factor of 10 compared with the pure Al metal. Salt spray corrosion testing also demonstrated the greatly improved corrosion resistance. Unlike the traditional hard anodized Al which presents a dull-colored surface, this newly developed anodized Al alloy possesses a very bright and shiny surface with good hardness and corrosion resistance.

Influence of skin hardness on dehydration kinetics of wine grapes.

Science.gov (United States)

Rolle, Luca; Caudana, Alberto; Giacosa, Simone; Gerbi, Vincenzo; Río Segade, Susana

2011-02-01

Knowledge of the influence of initial mechanical properties on the evolution of the weight loss of berries through the drying process is scarce. Therefore, the main purpose of this work was to investigate the effect of skin hardness at two different physiological stages of off-vine drying kinetics of grapes. Skin hardness was evaluated as the berry skin-break force parameter, measured by the texture analysis test. The decrease of berry weight as a function of the drying time was linear, indicating that the drying rates were constant within each cultivar studied (Moscato bianco and Erbaluce), and for each ripening stage and berry skin hardness. The drying rates decreased as berry skin hardness increased for the ripest grapes in the cultivars studied. The study allowed the assessment of the correlation between the skin hardness of fresh berries and the weight loss determined for different drying days. 2010 Society of Chemical Industry.

A hard-to-read font reduces the framing effect in a large sample.

Science.gov (United States)

Korn, Christoph W; Ries, Juliane; Schalk, Lennart; Oganian, Yulia; Saalbach, Henrik

2018-04-01

How can apparent decision biases, such as the framing effect, be reduced? Intriguing findings within recent years indicate that foreign language settings reduce framing effects, which has been explained in terms of deeper cognitive processing. Because hard-to-read fonts have been argued to trigger deeper cognitive processing, so-called cognitive disfluency, we tested whether hard-to-read fonts reduce framing effects. We found no reliable evidence for an effect of hard-to-read fonts on four framing scenarios in a laboratory (final N = 158) and an online study (N = 271). However, in a preregistered online study with a rather large sample (N = 732), a hard-to-read font reduced the framing effect in the classic "Asian disease" scenario (in a one-sided test). This suggests that hard-read-fonts can modulate decision biases-albeit with rather small effect sizes. Overall, our findings stress the importance of large samples for the reliability and replicability of modulations of decision biases.

Induction surface hardening of hard coated steels

Energy Technology Data Exchange (ETDEWEB)

Pantleon, K.; Kessler, O.; Hoffann, F.; Mayr, P. [Stiftung Inst. fuer Werkstofftechnik, Bremen (Germany)

1999-11-01

The properties of hard coatings deposited using CVD processes are usually excellent. However, high deposition temperatures negatively influence the substrate properties, especially in the case of low alloyed steels. Therefore, a subsequent heat treatment is necessary to restore the properties of steel substrates. Here, induction surface hardening is used as a method of heat treatment after the deposition of TiN hard coatings on AISI 4140 (DIN42CrMo4) substrates. The influences of the heat treatment on both the coating and the substrate properties are discussed in relation to the parameters of induction heating. Thereby, the heating time, heating atmosphere and the power input into the coating-substrate compounds are varied. As a result of induction surface hardening, the properties of the substrates are improved without losing good coating properties. High hardness values in the substrate near the interface allow the AISI 4140 substrates to support TiN hard coatings very well. Consequently, higher critical loads are measured in scratch tests after the heat treatment. Also, compressive residual stresses in the substrate are generated. In addition, only a very low distortion appears. (orig.)

Effect of surface integrity of hard turned AISI 52100 steel on fatigue performance

International Nuclear Information System (INIS)

Smith, Stephen; Melkote, Shreyes N.; Lara-Curzio, Edgar; Watkins, Thomas R.; Allard, Larry; Riester, Laura

2007-01-01

This paper addresses the relationship between surface integrity and fatigue life of hard turned AISI 52100 steel (60-62 HRC), with grinding as a benchmark. The impact of superfinishing on the fatigue performance of hard turned and ground surfaces is also discussed. Specifically, the surface integrity and fatigue life of the following five distinct surface conditions are examined: hard turned with continuous white layer, hard turned with no white layer, ground, and superfinished hard turned and ground specimens. Surface integrity of the specimens is characterized via surface topography measurement, metallography, residual stress measurements, transmission electron microscopy (TEM), and nano-indentation tests. High cycle tension-tension fatigue tests show that the presence of white layer does not adversely affect fatigue life and that, on average, the hard turned surface performs as well or better than the ground surface. The effect of superfinishing is to exaggerate these differences in performance. The results obtained from this study suggest that the effect of residual stress on fatigue life is more significant than the effect of white layer. For the hard turned surfaces, the fatigue life is found to be directly proportional to both the surface compressive residual stress and the maximum compressive residual stress. Possible explanations for the observed effects are discussed

DETERMINATION OF THE OPTIMAL TEMPERING TEMPERATURE IN HARD FACING OF THE FORGING DIES

Directory of Open Access Journals (Sweden)

Milan Mutavdžić

2012-06-01

Full Text Available Here is analyzed selection of the optimal technology for heat treatment during the reparation of the damaged forging dies. Those tools are manufactured from alloyed tool steels for operation at elevated temperatures. Those steels are prone to self-hardening, so in reparatory hard-facing they must be preheated, additionally heated and tempered. During the tempering, in temperature interval 500-600°C, a secondary increase of hardness and decrease of impact toughness occurs, the so-called reversible tempering brittleness. Here is shown that it can be avoided by application of metallurgical and technological measures. Metallurgical measures assume adequate selection of steels. Since the considered steels are per se prone to tempering brittleness, we conducted experimental investigations to define the technological measures to avoid it. Tests on models were conducted: tempering from different temperatures, slow heating and cooling in still air. Hardness measurements showed that at 520°C, the secondary increase of hardness occurs, with drop of the impact toughness. Additional hard-facing tests included samples tempered at various regimes. Samples were prepared for mechanical and metallographic investigations. Results presented illustrate influence of additional heat treatment on structure, hardness and mechanical properties of the hard-faced layers. This enabled establishing the possibility of avoiding the tempering brittleness through technological measures.

Determination of the optimal tempering temperature in hard facing of the forging dies

Directory of Open Access Journals (Sweden)

Milan Mutavdžić

2012-05-01

Full Text Available Here is analyzed selection of the optimal technology for heat treatment during the reparation of the damaged forging dies. Those tools are manufactured from alloyed tool steels for operation at elevated temperatures. Those steels are prone to self-hardening, so in reparatory hard-facing they must be preheated, additionally heated and tempered. During the tempering, in temperature interval 500-600°C, a secondary increase of hardness and decrease of impact toughness occurs, the so-called reversible tempering brittleness. Here is shown that it can be avoided by application of metallurgical and technological measures. Metallurgical measures assume adequate selection of steels. Since the considered steels are per se prone to tempering brittleness, we conducted experimental investigations to define the technological measures to avoid it. Tests on models were conducted: tempering from different temperatures, slow heating and cooling in still air. Hardness measurements showed that at 520°C, the secondary increase of hardness occurs, with drop of the impact toughness. Additional hard-facing tests included samples tempered at various regimes. Samples were prepared for mechanical and metallographic investigations. Results presented illustrate influence of additional heat treatment on structure, hardness and mechanical properties of the hard-faced layers. This enabled establishing the possibility of avoiding the tempering brittleness through technological measures. 

Effect of Nb element content in U-Zr-Nb alloy on hardness, microstructure and phase formation

International Nuclear Information System (INIS)

Masrukan; M Husna Al Hasa; Jan Setiawan; Slamet Pribadi

2015-01-01

Experiments to determine the effect of Nb element in the U-Zr alloys on hardness, microstructure and phase formation has been done. The addition of Nb element would effect the hardness, microstructure and phase which formed. The U-Zr-Nb alloy was made with the variation of Nb 2%, 5% and 8% by melting in an electric arc melting furnace that equipped with water cooling and the argon atmosphere. The U-Zr-Nb alloy to be cut divided to some testing, such as hardness test, microstructure, and phase analysis. Hardness testing was done by Vickers hardness testing equipment, microstructure by an optical microscope, and diffraction pattern by XRD and phase analysis was done by GSAS. Hardness testing results showed that the addition of 2% to 5% Nb element in U-Zr alloys will increased in hardness, but the addition of Nb element over 5% the hardness was decreased. Observations the microstructure showed that the addition of 2% to 5% Nb element, grains were formed from fine into coarse. Phase analysis for diffraction pattern showed that the phase changed from αU and γU (Zr,Nb)at 2% Nb to be αU, γU (Zr,Nb) and δ1 (UZr_2) phase at 5% and 8% Nb. Phase changes was followed by changes in its compositions. The composition of αU at 2% Nb was 40% increased to 81% at 5% Nb and decreased to 3.9% at 8% Nb. The composition of γU decreased from 59,86% to 14,91% with increased Nb from 2% to 5% and further increased to 52,74% at 8% Nb. (author)

Do the Hard Things First: A Randomized Controlled Trial Testing the Effects of Exemplar Selection on Generalization Following Therapy for Grammatical Morphology

Science.gov (United States)

Van Horne, Amanda Jean Owen; Fey, Marc; Curran, Maura

2017-01-01

Purpose: Complexity-based approaches to treatment have been gaining popularity in domains such as phonology and aphasia but have not yet been tested in child morphological acquisition. In this study, we examined whether beginning treatment with easier-to-inflect (easy first) or harder-to-inflect (hard first) verbs led to greater progress in the…

Changes in hardness of magnesium alloys due to precipitation hardening

Directory of Open Access Journals (Sweden)

Tatiana Oršulová

2018-04-01

Full Text Available This paper deals with the evaluation of changes in hardness of magnesium alloys during precipitation hardening that are nowadays widely used in different fields of industry. It focuses exactly on AZ31, AZ61 and AZ91 alloys. Observing material hardness changes serves as an effective tool for determining precipitation hardening parameters, such as temperature and time. Brinell hardness measurement was chosen based on experimental needs. There was also necessary to make chemical composition analysis and to observe the microstructures of tested materials. The obtained results are presented and discussed in this paper.

Abrasion Wear Resistance, Hardness and Microstructure of Hard Linings Deposited by Means of a Submerged Arc. Dureza, microestructura y resistencia al desgaste por abrasion de recargues duros depositados con arco sumergido

Energy Technology Data Exchange (ETDEWEB)

Paranhos, R; Alcoforado, J M; Castillo, J A; Sauer, A

1989-01-01

Consumable materials for submerged arc welding of the types alloyed flux-neutral electrode and neutral flux-alloyed electrode were used to form, through multipass welding, a light alloy hard lining of the C-Mn type on ASTM A36 Type structural steel. Emphasis was put on microstructural characterization of the linings surveyed under electron scanning microscopy, and tests were performed to study their hardness and abrasion wear resistance at low pressures. As a result of these tests, a great influence of welding parameters on hardness and abrasion resistance properties of the combination active flux-neutral electrode was noticed. As the results showed no relationship between the hardness and the abrasion wear resistance of the linings surveyed, an attempt was made to relate the resulting microstructure with their abrasion wear resistance. (Author)

Comparative study of carp otolith hardness: lapillus and asteriscus.

Science.gov (United States)

Ren, Dongni; Meyers, Marc André; Zhou, Bo; Feng, Qingling

2013-05-01

Otoliths are calcium carbonate biominerals in the inner ear of vertebrates; they play a role in balance, movement, and sound perception. Two types of otoliths in freshwater carp are investigated using nano- and micro-indentation: asteriscus and lapillus. The hardness, modulus, and creep of asteriscus (vaterite crystals) and lapillus (aragonite crystals) are compared. The hardness and modulus of lapillus are higher than those of asteriscus both in nano- and micro-testing, which is attributed to the different crystal polymorphs. Both materials exhibit a certain degree of creep, which indicates some time dependence of the mechanical behavior and is attributed to the organic components. The nano-indentation hardnesses are higher than micro-hardnesses for both otoliths, a direct result of the scale dependence of strength; fewer flaws are encountered by the nano than by the microindenter. Copyright © 2012 Elsevier B.V. All rights reserved.

Radiation hardness tests of double-sided 3D strip sensors with passing-through columns

Energy Technology Data Exchange (ETDEWEB)

Dalla Betta, Gian-Franco, E-mail: gianfranco.dallabetta@unitn.it [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); INFN TIFPA, Via Sommarive 14, I-38123 Trento (Italy); Betancourt, Christopher [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Boscardin, Maurizio; Giacomini, Gabriele [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive 18, I-38123 Trento (Italy); Jakobs, Karl; Kühn, Susanne [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Lecini, Besnik [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); Mendicino, Roberto [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); INFN TIFPA, Via Sommarive 14, I-38123 Trento (Italy); Mori, Riccardo; Parzefall, Ulrich [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Povoli, Marco [Dipartimento di Ingegneria Industriale, Università degli Studi di Trento, Via Sommarive 9, I-38123 Trento (Italy); Thomas, Maira [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Zorzi, Nicola [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive 18, I-38123 Trento (Italy)

2014-11-21

This paper deals with a radiation hardness study performed on double-sided 3D strip sensors with passing-through columns. Selected results from the characterization of the irradiated sensors with a beta source and a laser setup are reported and compared to pre-irradiation results and to TCAD simulations. The sensor performance in terms of signal efficiency is found to be in good agreement with that of other 3D sensors irradiated at the same fluences and tested under similar experimental conditions. - Highlights: • We report results from 3D silicon strip detectors irradiated up to HL-LHC fluences. • I–V curves, noise, charge collection measurements and laser scans are shown. • In all sensors, signals are distinguished from the noise already at low voltage. • Signal efficiency is in agreement with values expected from the electrode geometry. • Efficiency and spatial uniformity would benefit from higher operation voltages.

Radiation hardness tests of double-sided 3D strip sensors with passing-through columns

International Nuclear Information System (INIS)

Dalla Betta, Gian-Franco; Betancourt, Christopher; Boscardin, Maurizio; Giacomini, Gabriele; Jakobs, Karl; Kühn, Susanne; Lecini, Besnik; Mendicino, Roberto; Mori, Riccardo; Parzefall, Ulrich; Povoli, Marco; Thomas, Maira; Zorzi, Nicola

2014-01-01

This paper deals with a radiation hardness study performed on double-sided 3D strip sensors with passing-through columns. Selected results from the characterization of the irradiated sensors with a beta source and a laser setup are reported and compared to pre-irradiation results and to TCAD simulations. The sensor performance in terms of signal efficiency is found to be in good agreement with that of other 3D sensors irradiated at the same fluences and tested under similar experimental conditions. - Highlights: • We report results from 3D silicon strip detectors irradiated up to HL-LHC fluences. • I–V curves, noise, charge collection measurements and laser scans are shown. • In all sensors, signals are distinguished from the noise already at low voltage. • Signal efficiency is in agreement with values expected from the electrode geometry. • Efficiency and spatial uniformity would benefit from higher operation voltages

Modelling of nuclear explosions in hard rock sites

International Nuclear Information System (INIS)

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

1993-01-01

This study represents part of a larger effort to systematically model the effects of differing source region properties on ground motion from underground nuclear explosions at the Nevada Test Site. In previous work by the authors the primary emphasis was on alluvium and both saturated and unsaturated tuff. We have attempted to model events on Pahute Mesa, where either the working point medium, or some of the layers above the working point, or both, are hard rock. The complex layering at these sites, however, has prevented us from drawing unambiguous conclusions about modelling hard rock

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

Directory of Open Access Journals (Sweden)

Jiushu Xie

2016-09-01

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

Theoretical modeling developed to evaluate the hardness and reduced modulus for the C/a-Si composite film using nanoindentation tests

International Nuclear Information System (INIS)

Han, C.-F.; Lin, J.-F.; Chung, C.-K.; Wu, B.-H.

2008-01-01

A general mechanical model, which is composed of the mechanical models employed to describe the contact behaviors and deformations arising in all layers (including the substrate), is successfully developed in the present study for multilayer specimens in order to evaluate the contact projected area by a theoretical model, and thus the hardness and reduced modulus, using nanoindentation tests. The governing differential equations for the depth solutions of the indenter tip formed at all layers of the specimen under their contact load are developed individually. The influence of the material properties of the substrate on a multilayer specimen's hardness and reduced modulus at various indentation depths can thus be evaluated. Transition and pop-in occurred at depths near, but still before, the C (top layer)/a-Si (buffer layer) interface and the a-Si/Si (substrate) interface, respectively. Using the present analysis, the depths corresponding to the transition and pop-in behaviors can be predicted effectively

Effect of thermal transients on the hardness of Zircaloy fuel cladding

International Nuclear Information System (INIS)

Hobson, D.O.

1976-06-01

This study is directed toward the determination of the effects of annealing cycles with rapid heating rates, short hold times at specific temperatures, and rapid cool-down rates on the hardness of Zircaloy fuel cladding. These rapid annealing cycles are designed to provide preliminary annealing behavior data on Loss-of-Fluid-Test Reactor cladding samples. Information has been obtained on (1) the time dependence of the hardness as a function of annealing temperature, and (2) a correlation of single- and multitransient annealing relationships. Both single- and triple-cycle transients were used; four hold times at each of five maximum temperatures comprised the data set (each portion of the triple-cycle experiments had isothermal hold times equal to one-third of their analogous single-cycle times). It was found that there was little difference in the hardness response between single- and triple-cycle transients for a given total hold time at a particular temperature. Test temperatures range from 1000 to 1400 0 F (538 to 760 0 C) and hold times from 5 to 135 sec. The 1100 0 F (593 0 C) level was found to be the transition level for hardness changes, with shorter times (5 and 15 sec) effecting little or no hardness decrease and the longer times (45 and 135 sec) producing partially and fully annealed material, respectively. Temperatures equal to or greater than 1300 0 F (704 0 C) resulted in fully annealed material for all hold times. The 1000 0 F (538 0 C) tests produced no measurable softening

Standard Practice for Minimizing Dosimetry Errors in Radiation Hardness Testing of Silicon Electronic Devices Using Co-60 Sources

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This practice covers recommended procedures for the use of dosimeters, such as thermoluminescent dosimeters (TLD's), to determine the absorbed dose in a region of interest within an electronic device irradiated using a Co-60 source. Co-60 sources are commonly used for the absorbed dose testing of silicon electronic devices. Note 1—This absorbed-dose testing is sometimes called “total dose testing” to distinguish it from “dose rate testing.” Note 2—The effects of ionizing radiation on some types of electronic devices may depend on both the absorbed dose and the absorbed dose rate; that is, the effects may be different if the device is irradiated to the same absorbed-dose level at different absorbed-dose rates. Absorbed-dose rate effects are not covered in this practice but should be considered in radiation hardness testing. 1.2 The principal potential error for the measurement of absorbed dose in electronic devices arises from non-equilibrium energy deposition effects in the vicinity o...

Diffractive Production of Jets and Weak Bosons, and Tests of Hard-Scattering Factorization

CERN Document Server

Alvero, L; Terrón, J; Whitmore, J; Alvero, Lyndon; Collins, John C.; Terron, Juan; Whitmore, Jim

1999-01-01

We extract diffractive parton densities from diffractive, deep inelastic (DIS) ep data from the ZEUS experiment. Then we use these fits to predict the diffractive production of jets and of W's and Z's in p\\bar p collisions at the Tevatron. Although the DIS data require a hard quark density in the pomeron, we find fairly low rates for the Tevatron processes (a few percent of the inclusive cross section). This results from the combined effects of Q^{2} evolution and of a normalization of the parton densities to the data. The calculated rates for W production are generally consistent with the preliminary data from the Tevatron. However, the jet data from CDF with a ``Roman pot'' trigger are substantially lower than the results of our calculations; if confirmed, this would signal a breakdown of hard-scattering factorization.

Hard coal; Steinkohle

Energy Technology Data Exchange (ETDEWEB)

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

2013-04-01

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

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

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats, or hard caps... STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1720-1 Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color...

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

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats or hard caps... Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color from those worn by experienced miners shall be worn at...

Great microwave bursts and hard X-rays from solar flares

International Nuclear Information System (INIS)

Wiehl, H.J.; Batchelor, D.A.; Crannell, C.J.; Dennis, B.R.; Price, P.N.

1983-06-01

The microwave and hard X-ray charateristics of 13 solar flares that produced microwave fluxes greater than 500 Solar Flux Units were analyzed. These Great Microwave Bursts were observed in the frequency range from 3 to 35 GHz at Berne, and simultaneous hard X-ray observations were made in the energy range from 30 to 500 keV with the Hard X-Ray Burst Spectrometer on the Solar Maximum Mission spacecraft. The principal aim of this analysis is to determine whether or not the same distribution of energetic electrons can explain both emissions. Correlations were found between respective temporal characteristics and, for the first time, between microwave and hard X-ray spectral characteristics. A single-temperature and a multi-temperature model from the literature were tested for consistency with the coincident X-ray and microwave spectra at microwave burst maximum. Four events are inconsistent with both of the models tested, and neither of the models attempts to explain the high-frequency part of the microwave spectrum. A model in which the emissions above and below the peak frequency originate in two different parts of a diverging magnetic loop is proposed. With this model the entire microwave spectrum of all but one of the events is explained

Development of radiation hard components for ITER blanket remote handling system

Energy Technology Data Exchange (ETDEWEB)

Saito, Makiko, E-mail: saito.makiko@jaea.go.jp; Anzai, Katsunori; Maruyama, Takahito; Noguchi, Yuto; Ueno, Kenichi; Takeda, Nobukazu; Kakudate, Satoshi

2016-11-01

Highlights: • Clarify the components that will degrade by gamma ray irradiation. • Perform the irradiation tests to BRHS components. • Optimize the materials to increase the radiation hardness. - Abstract: The ITER blanket remote handling system (BRHS) will be operated in a high radiation environment (250 Gy/h max.) and must stably handle the blanket modules, which weigh 4.5 t and are more than 1.5 m in length, with a high degree of position and posture accuracy. The reliability of the system can be improved by reviewing the failure events of the system caused by high radiation. A failure mode and effects analysis (FMEA) identified failure modes and determined that lubricants, O-rings, and electric insulation cables were the dominant components affecting radiation hardness. Accordingly, we tried to optimize the lubricants and cables of the AC servo motors by using polyphenyl ether (PPE)-based grease and polyether ether ketone (PEEK), respectively. Materials containing radiation protective agents were also selected for the cable sheaths and O-rings to improve radiation hardness. Gamma ray irradiation tests were performed on these components and as a result, a radiation hardness of 8 MGy was achieved for the AC servo motors. On the other hand, to develop the radiation hardness and BRHS compatibility furthermore, the improvement of materials of cable and O ring were performed.

Prediction of hardness in pieces of quenched and tempered steel

International Nuclear Information System (INIS)

Yanzon, Rodolfo Carlos; Rodriguez, Augusto; Sanchez, Arlington Ricardo

2006-01-01

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

Elasticity of Hard-Spheres-And-Tether Systems

International Nuclear Information System (INIS)

Farago, O.; Kantor, Y.

1999-01-01

Physical properties of a large class of systems ranging from noble gases to polymers and rubber are primarily determined by entropy, while the internal energy plays a minor role. Such systems can be conveniently modeled and numerically studied using ''hard' (i.e., ''infinity-or-zero'') potentials, such as hard sphere repulsive interactions, or inextensible (''tether'') bonds which limit the distance between the bonded monomers, but have zero energy at all permitted distances. The knowledge of elastic constants is very important for understanding the behavior of entropy-dominated systems. Computational methods for determination of the elastic constants in such systems are broadly classified into ''strain'' methods and (fluctuation methods. In the former, the elastic constants are extracted from stress-strain relations, while in the latter they are determined from measurements of stress fluctuations. The fluctuation technique usually enables more accurate and well-controlled determination of the elastic constants since in this method the elastic constants are computed directly from simulations of the un strained system with no need to deform the simulation cell and perform numerical differentiations. For central forces systems, the original ''fluctuation'' formalism can be applied provided the pair potential is twice differentiable. We have extended this formalism to apply to hard-spheres-and-tether models in which this requirement is not fulfilled. We found that for such models the components of the tensor of elastic constants can be related to (two-, three- and four-point) probability densities of contacts between hard spheres and stretched bonds. We have tested our formalism on simple (phantom networks and three-dimensional hard spheres systems

The role of ultrasonic velocity and Schmidt hammer hardness - The simple and economical non-destructive test for the evaluation of mechanical properties of weathered granite

Science.gov (United States)

Jobli, Ahmad Fadzil; Hampden, Ahmad Zaidi; Tawie, Rudy

2017-08-01

One of the most significant techniques for evaluation of rock strength is by using the simple and economical non-destructive test (NDT). Previous literatures confirm that there were good correlations between NDTs to the strength properties of granite rocks. The present work deals with the use of Ultrasonic Pulse Velocity and Schmidt Hammer Hardness test to predict the mechanical properties of weathered granite. Cylindrical specimens with the length to diameter ratio of two were prepared for this study and were characterized based on different weathering states. Each of the rock specimens was tested under non-destructive test and then followed by uniaxial compression test to assess the mechanical properties. It was found that good correlations established between the NDTs and the uniaxial compressive strength. The correlation between uniaxial compressive strength and rebound hardness number was demonstrated by exponential form; UCS = 6.31e0.057N, while linear correlations was obtained between the uniaxial compressive strength and the ultrasonic pulse velocity; UCS = 0.023Vp - 21.43. It was also noticed that the increase of uniaxial compression strength was parallel to the increase of elastic modulus and can be presented by a linear equation; UCS = 1.039Et50 + 4.252. Based on the reported results, it is clear that the mechanical properties or weathered granite can be estimated by means of non-destructive test.

DEVELOPMENT AND TESTING OF AN ANTI-TOBACCO SCHOOL-BASED CURRICULUM FOR DEAF AND HARD OF HEARING YOUTH

Science.gov (United States)

Berman, Barbara A.; Guthmann, Debra S.; Crespi, Catherine M.; Liu, Weiqing

2010-01-01

Although school-based programming is an important element of the effort to curb tobacco use among young people, a comprehensive tailored curriculum has not been available for deaf and hard of hearing youth. The authors describe the drafting of such a program by expert educators, and findings from a test of the curriculum using a quasi-experimental non-equivalent control group design involving four schools for the deaf in three states. Two schools received the curriculum and two served as non-curriculum controls. Survey data were collected from students in grades 7–12 at baseline and at the start and end of three school years, from 511 to 616 students at each time point, to assess tobacco use, exposure to tobacco education, and tobacco-related knowledge, attitudes and practices. Changes within each school were assessed as the difference between the baseline survey and the average of the last four follow-up surveys. Current (past month) smoking declined significantly at one intervention school (22.7% baseline to 7.9% follow-up, p=.007) and current smokeless tobacco use at the other (7.5% baseline to 2.5% follow-up, p=.03). Exposure to tobacco prevention education, and anti-tobacco attitudes and knowledge each increased significantly at one or both schools. One control school experienced a significant decline in tobacco education exposure (pdeaf and hard of hearing youth. PMID:21449256

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

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

Prediction of hardness for Al-Cu-Zn alloys in as-cast and quenching conditions

International Nuclear Information System (INIS)

Villegas-Cardenas, J. D.; Saucedo-Munoz, M. L.; Lopez-Hirata, V. M.; Dorantes Rosales, H. J.

2014-01-01

This work presents a new experimental and numerical methodology in order to predict the hardness in the as-cast, and solution treated and quenched Al-Cu-Zn alloys. Chemical composition of alloys is located inside two straight lines represented by two equations. Eight different compositions were selected from each line. All the alloys were characterized for light microscope, scanning electron microscope, X-ray diffraction and Rockwell B hardness test. The equilibrium phases were obtained at different temperatures by Thermo-Calc. The microstructure characterization and regression analysis enabled to determine the phase transformations and two equations of hardness assessment. The combination of hardness equations and composition line equations permitted to estimate the hardness of any alloy composition inside this zone. This was verified by calculating hardness with the information reported in other works, with an error lower than 7% in the estimated hardness. (Author)

ASSOCIATION BETWEEN RETINAL HARD EXUDATES AND DYSLIPIDEMIA IN TYPE 2 DIABETIC PATIENTS IN RURAL KARNATAKA

Directory of Open Access Journals (Sweden)

Arun Kumar B.

2015-10-01

Full Text Available AIM: To evaluate the association of elevated serum lipids with retinal hard exudates in type 2 diabetic patients in rural Karnataka. MATERIAL AND METHODS : Hospital based cross sectional study which included 60 (n=60 type 2 diabetic patients (60 eyes fulfilling the inclusion criteria. Patients were subjected to detailed ocular examination, fundus examination done under full dilatation using indirect ophth almoscope with 20D lens and slit lamp biomicroscope with 90D lens. Fundus photographs were obtained using fundus camera. Grading of retinal hard exudates performed by utilizing modified Airlie House classification. The modified Airlie House Classification used is as follows: Grade 0 - No evidence of hard exudates; Grade 1 : Questionable hard exudates present; Grade 2 : Hard exudates less than standard photograph 3; Grade 3 : Hard exudates greater than or equal to standard photograph 3, but less than standard p hotograph 5; Grade 4 : Hard exudates greater than or equal to standard photograph 5, but less than standard photograph 4 and Grade 5 : Hard exudates greater than or equal to standard photograph 4. These grades were further divided into three groups of patie nt severity as follows: Group 1 (absent or minimal hard exudates included patients with Grade 0, 1 or 2 hard exudates; Group 2 (hard exudates present included patients with Grade 3 or 4 hard exudates and Group 3 (prominent hard exudates included patient s with Grade 5 hard exudates. Fasting lipid profile including serum total cholesterol, low density lipoproteins, very low density lipoproteins, high density lipoproteins and triglycerides was obtained. Association of dyslipidemia with retinal hard exudates was analysed using one way ANOVA test. RESULTS: On statistical analysis with ANOVA test retinal hard exudates were significantly associated with elevated total cholesterol (p= .0001, triglycerides (p= .0001, serum LDL (p=.008, serum VLDL (p=.012, and negative correlation was found

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

International Nuclear Information System (INIS)

Zhou, Y.; Hall, C.K.; Stell, G.

1995-01-01

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

What drives the efficiency of hard coal fuelled electricity generation? : an empirical assessment

OpenAIRE

Hoffmann, Tim; Voigt, Sebastian

2009-01-01

The efficiency of electricity generation in hard coal fired power plants varies considerably from country to country and over time. These differences occur both between developing and developed countries and between industrialised nations. The econometric analysis presented in this paper tests for the reasons of these discrepancies. In this examination abundance of hard coal and the price of hard coal are the two variables of our major interest. We assume that countries with an abundance of h...

Characterisation of weldment hardness, impact energy and microstructure in API X65 steel

International Nuclear Information System (INIS)

Hashemi, S.H.; Mohammadyani, D.

2012-01-01

The variation of microstructure and mechanical properties in various sub-zones of double submerged arc welded line pipe steel of grade API X65 was investigated. Instrumented Charpy V-notch tests and Vickers hardness experiments were conducted on the fusion zone, base metal and heat affected zone of the weld joint in 14.3 mm thick, 1219 mm outside diameter spiral pipeline. The lowest impact energy and the highest hardness level (160J and 218 HV, respectively) were recorded in the fusion zone. The low energy and high hardness characteristics of the seam weld can be attributed to its cast microstructure and the presence of grain boundary phases (such as proeutectoid ferrite), confirmed by standard metallographic observation. Despite this, service requirements set by the API 5L industry code (minimum impact energy of 73J, maximum hard spots of 350 HV) were fulfilled by the tested steel. Highlights: ► Experimental study of API X65 steel microstructure. ► Analysis of the relationship between X65 steel microstructure and hardness. ► Analysis of the relationship between X65 steel microstructure and impact energy. ► Presentation of detailed technical information on DSA welding in spiral pipes.

Hard Coat Layers by PE-CVD Process for the Top Surface of Touch Panel

International Nuclear Information System (INIS)

Okunishi, T; Sato, N; Yazawa, K

2013-01-01

In order to protect surface from damages, the high pencil hardness and the high abrasion resistance are required for the hard coat layers on polyethylene telephthalate (PET) films for the application of touch panel surface. We have already found that the UV-curing-hard-coat-polymer (UHP) coated PET films show the poor abrasion resistance, while they have the high pencil hardness. It reveals that the abrasion resistance of hard coat layers of the UHP is not simply dependent on the pencil hardness. In this work, we have studied to improve the abrasion resistance of SiOC films as hard coat layers, which were formed by PE-CVD process on UHP coated PET. The abrasion resistance was evaluated by Taber abrasion test. PE-CVD hard coat layers which formed on UHP coater PET films have showed the better abrasion resistance and have the possibility of substitution to the thin glass sheets for touch panel application.

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

Directory of Open Access Journals (Sweden)

Robert Sonntag

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

Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel

Science.gov (United States)

Liu, Hanghang; Fu, Paixian; Liu, Hongwei; Li, Dianzhong

2018-01-01

The strength-toughness combination and hardness uniformity in large cross-section 718H pre-hardened mold steel from a 20 ton ingot were investigated with three different heat treatments for industrial applications. The different microstructures, including tempered martensite, lower bainite, and retained austenite, were obtained at equivalent hardness. The microstructures were characterized by using metallographic observations, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and electron back-scattered diffraction (EBSD). The mechanical properties were compared by tensile, Charpy U-notch impact and hardness uniformity tests at room temperature. The results showed that the test steels after normalizing-quenching-tempering (N-QT) possessed the best strength-toughness combination and hardness uniformity compared with the conventional quenched-tempered (QT) steel. In addition, the test steel after austempering-tempering (A-T) demonstrated the worse hardness uniformity and lower yield strength while possessing relatively higher elongation (17%) compared with the samples after N-QT (14.5%) treatments. The better ductility of A-T steel mainly depended on the amount and morphology of retained austenite and thermal/deformation-induced twined martensite. This work elucidates the mechanisms of microstructure evolution during heat treatments and will highly improve the strength-toughness-hardness trade-off in large cross-section steels. PMID:29642642

Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel

Directory of Open Access Journals (Sweden)

Hanghang Liu

2018-04-01

Full Text Available The strength-toughness combination and hardness uniformity in large cross-section 718H pre-hardened mold steel from a 20 ton ingot were investigated with three different heat treatments for industrial applications. The different microstructures, including tempered martensite, lower bainite, and retained austenite, were obtained at equivalent hardness. The microstructures were characterized by using metallographic observations, scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and electron back-scattered diffraction (EBSD. The mechanical properties were compared by tensile, Charpy U-notch impact and hardness uniformity tests at room temperature. The results showed that the test steels after normalizing-quenching-tempering (N-QT possessed the best strength-toughness combination and hardness uniformity compared with the conventional quenched-tempered (QT steel. In addition, the test steel after austempering-tempering (A-T demonstrated the worse hardness uniformity and lower yield strength while possessing relatively higher elongation (17% compared with the samples after N-QT (14.5% treatments. The better ductility of A-T steel mainly depended on the amount and morphology of retained austenite and thermal/deformation-induced twined martensite. This work elucidates the mechanisms of microstructure evolution during heat treatments and will highly improve the strength-toughness-hardness trade-off in large cross-section steels.

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

Science.gov (United States)

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

2016-01-01

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

Hard-driven rail-gun tests

International Nuclear Information System (INIS)

Peterson, D.R.; Adams, D.F.; Cummings, C.E.; Fowler, C.M.; Kerrisk, J.F.; Marsh, S.P.; Parker, J.V.

1983-01-01

A number of prototype rail-gun designs have been tested, powered by explosive magnetic flux compression generators. Peak currents as high as 1.3 MA were delivered. Rail guns with 50-mm-thick Kevlar fiberwound structural shells were able to survive these high currents with minimum mechanical damage and were refired after enlarging the bores 0.2 to 0.4 mm to remove arc damage. In some tests, mechanical damage occurred that was apparently caused by the rebound of the gun after firing. Although the Kevlar shells had more than adequate strength, they appeared to lack sufficient stiffness, allowing excessive deflections. The use of a steel structural shell with a Kevlar sleeve was an improvement. Intrusion into the seams of the rail guns and condensation of material from the plasma armature were observed. Improved sealing of seams is indicated. In some cases, we suspect maldistribution of current within the gun; that is, not all the current delivered to the breech of the gun seemed to reach the plasma armature. Experiments are being designed to quantify the effects discussed. Rail guns of advanced design are being fabricated. An 18-g titanium projectile was accelerated to 2.4 km/s in a 16-mm-round-bore, 0.6-m-long gun, 4-6 g polycarbonate projectiles were accelerated to 3.5 km/s in 13-mm-square-bore, 1.2-m-long rail guns. All tests were conducted at atmospheric pressure

Using hardness to model yield and tensile strength

Energy Technology Data Exchange (ETDEWEB)

Hawk, Jeffrey A.; Dogan, Omer N.; Schrems, Karol K.

2005-02-01

The current direction in hardness research is towards smaller and smaller loads as nano-scale materials are developed. There remains, however, a need to investigate the mechanical behavior of complex alloys for severe environment service. In many instances this entails casting large ingots and making numerous tensile samples as the bounds of the operating environment are explored. It is possible to gain an understanding of the tensile strength of these alloys using room and elevated temperature hardness in conjunction with selected tensile tests. The approach outlined here has its roots in the work done by Tabor for metals and low alloy and carbon steels. This research seeks to extend the work to elevated temperatures for multi-phase, complex alloys. A review of the approach will be given after which the experimental data will be examined. In particular, the yield stress and tensile strength will be compared to their corresponding hardness based values.

It must be hard to stay so close

CERN Multimedia

Rossi, L

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

Grain characterization and milling behaviour of near-isogenic lines differing by hardness.

Science.gov (United States)

Greffeuille, V; Abecassis, J; Rousset, M; Oury, F-X; Faye, A; L'Helgouac'h, C Bar; Lullien-Pellerin, V

2006-12-01

Wheat grain hardness is a major factor affecting the milling behaviour and end-product quality although its exact structural and biochemical basis is still not understood. This study describes the development of new near-isogenic lines selected on hardness. Hard and soft sister lines were characterised by near infrared reflectance (NIR) and particle size index (PSI) hardness index, grain protein content, thousand kernel weight and vitreousness. The milling behaviour of these wheat lines was evaluated on an instrumented micromill which also measures the grinding energy and flour particle size distribution was investigated by laser diffraction. Endosperm mechanical properties were measured using compression tests. Results pointed out the respective effect of hardness and vitreousness on those characteristics. Hardness was shown to influence both the mode of fracture and the mechanical properties of the whole grain and endosperm. Thus, this parameter also acts on milling behaviour. On the other hand, vitreousness was found to mainly play a role on the energy required to break the grain. This study allows us to distinguish between consequences of hardness and vitreousness. Hardness is suggested to influence the adhesion forces between starch granules and protein matrix whereas vitreousness would rather be related to the endosperm microstructure.

Design and implementation of reliability evaluation of SAS hard disk based on RAID card

Science.gov (United States)

Ren, Shaohua; Han, Sen

2015-10-01

Because of the huge advantage of RAID technology in storage, it has been widely used. However, the question associated with this technology is that the hard disk based on the RAID card can not be queried by Operating System. Therefore how to read the self-information and log data of hard disk has been a problem, while this data is necessary for reliability test of hard disk. In traditional way, this information can be read just suitable for SATA hard disk, but not for SAS hard disk. In this paper, we provide a method by using LSI RAID card's Application Program Interface, communicating with RAID card and analyzing the feedback data to solve the problem. Then we will get the necessary information to assess the SAS hard disk.

Effect of Anneal temperature and Time on Change of Texture and Hardness of Al-Cu-Mg

International Nuclear Information System (INIS)

Masrukan; Adolf Asih, S.

2000-01-01

Observation of the effect of annealing temperature to its texture and hardness of the Al-Cu-Mg has been done. In this experiments aluminium alloy powder and 5 pieces cubes of this alloy with size of 8 x 8 x 8 mm 3 were used. The powder was not annealed, 2 pieces cube were annealed for 20 hours at temperatures of 200 o C and 300 o respectively, finally 3 pieces cube were annealed at temperature of 400 o C. Texture measurement was done using x-ray diffraction with wave length of 1.78892 A using inverse pole figure method. The hardness testing results at constant temperature of 400 o C and various time indicated that the hardness values are decreased with increasing annealed time. Also, at hardness testing for constant time and various annealing temperatures indicated that the hardness values decreased with increasing annealing temperature

Fabrication of tungsten probe for hard tapping operation in atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Han, Guebum, E-mail: hanguebum@live.co.kr [Department of Physics and Optical Engineering, Rose-Hulman Institute of Technology, 5500 Wabash Avenue, Terre Haute, Indiana 47803 (United States); Department of Mechanical Design and Robot Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 139-743 (Korea, Republic of); Ahn, Hyo-Sok, E-mail: hsahn@seoultech.ac.kr [Manufacturing Systems and Design Engineering Programme, Seoul National University of Science & Technology, 232 Gongneung-ro, Nowon-gu, Seoul 139-743 (Korea, Republic of)

2016-02-15

We propose a method of producing a tungsten probe with high stiffness for atomic force microscopy (AFM) in order to acquire enhanced phase contrast images and efficiently perform lithography. A tungsten probe with a tip radius between 20 nm and 50 nm was fabricated using electrochemical etching optimized by applying pulse waves at different voltages. The spring constant of the tungsten probe was determined by finite element analysis (FEA), and its applicability as an AFM probe was evaluated by obtaining topography and phase contrast images of a Si wafer sample partly coated with Au. Enhanced hard tapping performance of the tungsten probe compared with a commercial Si probe was confirmed by conducting hard tapping tests at five different oscillation amplitudes on single layer graphene grown by chemical vapor deposition (CVD). To analyze the damaged graphene sample, the test areas were investigated using tip-enhanced Raman spectroscopy (TERS). The test results demonstrate that the tungsten probe with high stiffness was capable of inducing sufficient elastic and plastic deformation to enable obtaining enhanced phase contrast images and performing lithography, respectively. - Highlights: • We propose a method of producing highly stiff tungsten probes for hard tapping AFM. • Spring constant of tungsten probe is determined by finite element method. • Enhanced hard tapping performance is confirmed. • Tip-enhanced Raman spectroscopy is used to identify damage to graphene.

Fabrication of tungsten probe for hard tapping operation in atomic force microscopy

International Nuclear Information System (INIS)

Han, Guebum; Ahn, Hyo-Sok

2016-01-01

We propose a method of producing a tungsten probe with high stiffness for atomic force microscopy (AFM) in order to acquire enhanced phase contrast images and efficiently perform lithography. A tungsten probe with a tip radius between 20 nm and 50 nm was fabricated using electrochemical etching optimized by applying pulse waves at different voltages. The spring constant of the tungsten probe was determined by finite element analysis (FEA), and its applicability as an AFM probe was evaluated by obtaining topography and phase contrast images of a Si wafer sample partly coated with Au. Enhanced hard tapping performance of the tungsten probe compared with a commercial Si probe was confirmed by conducting hard tapping tests at five different oscillation amplitudes on single layer graphene grown by chemical vapor deposition (CVD). To analyze the damaged graphene sample, the test areas were investigated using tip-enhanced Raman spectroscopy (TERS). The test results demonstrate that the tungsten probe with high stiffness was capable of inducing sufficient elastic and plastic deformation to enable obtaining enhanced phase contrast images and performing lithography, respectively. - Highlights: • We propose a method of producing highly stiff tungsten probes for hard tapping AFM. • Spring constant of tungsten probe is determined by finite element method. • Enhanced hard tapping performance is confirmed. • Tip-enhanced Raman spectroscopy is used to identify damage to graphene.

Production and mechanical properties of sintered carbides (hard steels WC-Co)

International Nuclear Information System (INIS)

Batalha, G.F.

1987-09-01

Densification and mechanical characteristics or WC-Co Cemented Carbides, were investigated by dilatometry, Hardness and bending tests, as a function of the two principal micro-structural parameters: the cobalt content and the particle size of carbide crystals. Vickers hardness of the studied compositions showed a linear variation with the increase of the cobalt content. By three point bending, the transverse rupture strenght increases with cobalt content, however, for larger grain size reaches a maximum, eventually reduced by brittle phases and incomplete dispersion. The results of brittle facture tests were statistically analised and fitted better to the 'Weakest Link Model' (Weibull distribution) than the 'Chain Model' (Gaussian distribution). (author) [pt

Design, realization and test of a rad-hard 2D-compressor and packing chip for high energy physics experiments

International Nuclear Information System (INIS)

Antinori, Samuele; Falchieri, Davide; Gabrielli, Alessandro; Gandolfi, Enzo

2004-01-01

CARLOSv3 is a third version of a chip that plays a significant role in the data acquisition chain of the A Large Ion Collider Experiment Inner Tracking System experiment. It has been designed and realized with a 0.25 μm CMOS 3-metal rad-hard digital library. The chip elaborates and compresses, by means of a bi-dimensional compressor, data belonging to a so-called event. The compressor looks for cross-shaped clusters within the whole data set coming from the silicon detector. To test the chip a specific PCB has been designed; it contains the connectors for probing the ASIC with a pattern generator and a logic state analyzer. The chip is inserted on the PCB using a ZIF socket. This allows to test the 35 packaged samples out of the total amount of bare chips we have from the foundry. The test phase has shown that 32 out of 35 chips under test work well. It is planned to redesign a new version of the chip by adding extra features and to submit the final version of CARLOS upon the final DAQ chain will be totally tested both in Bologna and at CERN

Evaluation of hardness and colour change of soft liners after accelerated ageing.

Science.gov (United States)

Mancuso, Daniela Nardi; Goiato, Marcelo Coelho; Zuccolotti, Bruna Carolina Rossatti; Moreno, Amália; dos Santos, Daniela Micheline

2009-07-01

Soft liners have been developed to offer comfort to denture wearers. However, this comfort is compromised when there is a change in the properties of the material, causing colour change, solubility, absorption and hardening. These characteristics can compromise the longevity of soft liners. The aim of this in vitro study was to investigate the effect of ageing on both the hardness and colour change of two soft liners following accelerated ageing. Two denture liners, one resin based (Trusoft, Bosworth, Illinois, USA) and one silicone based (Ufi Gel P, Voco GMBH, Cuxhaven, Germany), were tested in this study for both hardness (using the Shore A scale) and colour change (using the CIE L*a*b* colour scale), initially and after 1008 hours (6 weeks) of accelerated ageing. Statistical analysis was performed using the unpaired t-test with the Welch correction. These indicated that both materials increased in hardness and underwent colour change after accelerated ageing. The initial hardness of Trusoft was far lower than that of Ufi Gel P (18.2 Shore A units vs 34.8 Shore A units). However, for Trusoft the changes for both hardness (from 18.2 to 52.1 Shore A units) and colour change (16.85 on the CIE L*a*b* colour scale) were greater than those for Ufi Gel P, for which hardness changed from 34.8 to 36.5 Shore A units and the colour change was 5.19 on the CIE L*a*b* colour scale. Ufi Gel P underwent less hardness and colour change after accelerated ageing than Trusoft. On the other hand, the use of Trusoft may be preferable in cases where initial softness is a major consideration, such as when relining an immediate denture after implant surgery.

The effect of disinfectant solutions on the hardness of acrylic resin denture teeth.

Science.gov (United States)

Pavarina, A C; Vergani, C E; Machado, A L; Giampaolo, E T; Teraoka, M T

2003-07-01

This investigation studied the effects of disinfectant solutions on the hardness of acrylic resin denture teeth. The occlusal surfaces of 64 resin denture teeth were ground flat with abrasives up to 400-grit silicon carbide paper. Measurements were made after polishing and after the specimens were stored in water at 37 degrees C for 48 h. The specimens were then divided into four groups and immersed in chemical disinfectants (4% chlorhexidine; 1% sodium hypochlorite and sodium perborate) for 10 min. The disinfection methods were performed twice to simulate clinical conditions and hardness measurements were made. Specimens tested as controls were immersed in water during the same disinfection time. Eight specimens were produced for each group. After desinfection procedures, testing of hardness was also performed after the samples were stored at 37 degrees C for 7, 30, 60, 90 and 120 days. Data were analysed using two-way analysis of variance (anova) and Tukey's test at 95% confidence level. According to the results, no significant differences were found between materials and immersion solutions (P > 0.05). However, a continuous decrease in hardness was noticed after ageing (P surfaces of both acrylic resin denture teeth softened upon immersion in water regardless the disinfecting solution.

Chemical hardness and density functional theory

Indian Academy of Sciences (India)

Unknown

RALPH G PEARSON. Chemistry Department, University of California, Santa Barbara, CA 93106, USA. Abstract. The concept of chemical hardness is reviewed from a personal point of view. Keywords. Hardness; softness; hard & soft acids bases (HSAB); principle of maximum hardness. (PMH) density functional theory (DFT) ...

Hardness variability in commercial technologies

International Nuclear Information System (INIS)

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

1994-01-01

The radiation hardness of commercial Floating Gate 256K E 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 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 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

Hardness and microstructure analysis of damaged gear caused by adhesive wear

Science.gov (United States)

Mahendra, Rizky Budi; Nugroho, Sri; Ismail, Rifky

2018-03-01

This study was a result from research on repairing project of damaged elevator gear box. The objective of this research is to analyze the failure part on elevator gearbox at flourmill factory. The equipment was damaged after one year installed and running on factory. Severe wear was occurred on high speed helical gear. These helical gear was one of main part of elevator gearbox in flour mill manufacture. Visually, plastic deformation didn't occurred and not visible on the failure helical gear shaft. Some test would be performed to check the chemical composition, microstructure and hardness of failure helical gear. The material of failure helical gear shaft was a medium carbon steel alloy. The microstructure was showed a martensitic phase formed on the surface to the center area of gear shaft. Otherwise, the depth of hardness layer slight formed on surface and lack depth of hardness layer was a main trigger of severe wear. It was not enough to resist wear due to friction caused by rolling and sliding on surface between high speed gear and low speed gear. Enhancement of hardness layer on surface and depth of hardness layer will make the component has more long life time. Furthermore, to perform next research is needed to analyze the reliability of enhanced hardness on layer and depth of hardness layer on helical gear shaft.

Determination of adhesion between thermoplastic and liquid silicone rubbers in hard-soft-combinations via mechanical peeling test

Science.gov (United States)

Kühr, C.; Spörrer, A.; Altstädt, V.

2014-05-01

The production of hard-soft-combinations via multi injection molding gained more and more importance in the last years. This is attributed to different factors. One principle reason is that the use of two-component injection molding technique has many advantages such as cancelling subsequent and complex steps and shortening the process chain. Furthermore this technique allows the combination of the properties of the single components like the high stiffness of the hard component and the elastic properties of the soft component. Because of the incompatibility of some polymers the adhesion on the interface has to be determined. Thereby adhesion is not only influenced by the applied polymers, but also by the injection molding parameters and the characteristics of the mold. Besides already known combinations of thermoplastics with thermoplastic elastomers (TPE), there consists the possibility to apply liquid silicone rubber (LSR) as soft component. A thermoplastic/LSR combination gains in importance due to the specific advantages of LSR to TPE. The faintly adhesion between LSR and thermoplastics is currently one of the key challenges when dealing with those combinations. So it is coercively necessary to improve adhesion between the two components by adding an adhesion promoter. To determine the promoters influence, it is necessary to develop a suitable testing method to investigate e.g. the peel resistance. The current German standard "VDI Richtlinie 2019', which is actually only employed for thermoplastic/TPE combinations, can serve as a model to determine the adhesion of thermoplastic/LSR combinations.

Distributed data fusion across multiple hard and soft mobile sensor platforms

Science.gov (United States)

Sinsley, Gregory

is a younger field than centralized fusion. The main issues in distributed fusion that are addressed are distributed classification and distributed tracking. There are several well established methods for performing distributed fusion that are first reviewed. The chapter on distributed fusion concludes with a multiple unmanned vehicle collaborative test involving an unmanned aerial vehicle and an unmanned ground vehicle. The third issue this thesis addresses is that of soft sensor only data fusion. Soft-only fusion is a newer field than centralized or distributed hard sensor fusion. Because of the novelty of the field, the chapter on soft only fusion contains less background information and instead focuses on some new results in soft sensor data fusion. Specifically, it discusses a novel fuzzy logic based soft sensor data fusion method. This new method is tested using both simulations and field measurements. The biggest issue addressed in this thesis is that of combined hard and soft fusion. Fusion of hard and soft data is the newest area for research in the data fusion community; therefore, some of the largest theoretical contributions in this thesis are in the chapter on combined hard and soft fusion. This chapter presents a novel combined hard and soft data fusion method based on random set theory, which processes random set data using a particle filter. Furthermore, the particle filter is designed to be distributed across multiple robots and portable computers (used by human observers) so that there is no centralized failure point in the system. After laying out a theoretical groundwork for hard and soft sensor data fusion the thesis presents practical applications for hard and soft sensor data fusion in simulation. Through a series of three progressively more difficult simulations, some important hard and soft sensor data fusion capabilities are demonstrated. The first simulation demonstrates fusing data from a single soft sensor and a single hard sensor in

Development and testing of an antitobacco school-based curriculum for deaf and hard of hearing youth.

Science.gov (United States)

Berman, Barbara A; Guthmann, Debra S; Crespi, Catherine M; Liu, Weiqing

2011-01-01

A tobacco use prevention curriculum tailored for deaf/hard of hearing youth was tested using a quasi-experimental design. Two schools for the deaf received the curriculum; two served as noncurriculum controls. Surveys assessed changes in tobacco use, tobacco education exposure, and tobacco-related attitudes and knowledge among students in grades 7-12 over 3 school years (n = 511-616). Current (past month) smoking decreased significantly at one intervention school (23% to 8%,p = .007), and current smokeless tobacco use at the other (7.5% to 2.5%, p = .03). Tobacco education exposure and antitobacco attitudes and knowledge increased significantly at one or both intervention schools. At one control school, reported tobacco education exposure decreased (p < .001) and antitobacco attitudes increased (p = .01). The results indicate that the curriculum increased perceived tobacco education exposure and significantly affected tobacco-related practices, attitudes, and knowledge.

Effect of Heat treatment on Hardness and Corrosion Resistance of Super Cast Iron

Energy Technology Data Exchange (ETDEWEB)

Lee, Roun; Kim, Young Sik [Andong National University, Andong (Korea, Republic of)

2014-07-15

In fossil-fuel-fired power plants, a variety of pollutants are produced from the combustion of conventional fuels such as coal, oil and gas. Major component of such pollution are ash and corrosive chemicals, which also destroy pumps and piping; by causing erosion/corrosion, pitting, and wear. In order to over come such damage, materials with high hardness and high corrosion resistance are needed. In this work, we melted super-cast-iron with excellent corrosion resistance and high hardness. To elucidate the effect of heat treatment, microstructural analysis, hardness measurement, and corrosion tests were performed. Test results revealed that the super-cast-iron had several tens better corrosion resistance than 316 L stainless steel, and it also had a high surface hardness (> HRC45). High hardness, in spite of its low carbon content (0.74%C), could resulted from a hardening heat treatment to precipitate sufficient Cr{sub 7}C{sub 3} and Cr{sub 2}3C{sub 6}. Also, it was concluded that the excellent corrosion resistance of the super-cast-iron was due to the increase of the relative chromium content by minimizing the carbon content, and by the enhancement of passive film by the addition of Cr, Mo, Cu, and W.

Microfabrication of hard x-ray lenses

DEFF Research Database (Denmark)

Stöhr, Frederik

This thesis deals with the development of silicon compound refractive lenses (Si-CRLs) for shaping hard x-ray beams. The CRLs are to be fabricated using state of the art microfabrication techniques. The primary goal of the thesis work is to produce Si-CRLs with considerably increased structure...... and characterized with respect to their shape. Their optical performances were tested at the European Synchrotron Radiation Facility (ESRF). Two 1D-focusing Si-CRLs suitable as condensers in hard-XRM were developed utilizing the aforementioned two different strategies. The first Si-condenser showed focusing of a 56...... of space for sample surroundings and ensure low-divergent and wide x-ray beams with narrow waists. Both results are substantial improvements to what was available at the start of this thesis work. The challenge of making x-ray objectives in silicon by interdigitation of lenslets alternately focusing...

Application of Hard Metal Weld Deposit in the Area of Mixing Organic Materials

Directory of Open Access Journals (Sweden)

Jiří Votava

2014-01-01

Full Text Available Any machine part is subject to degradation processes. Intensive wear occurs either when two bearing surfaces come into contact or when loose particles rub the function surface of a machine part. Soil processing machines are a good example. A similar process of abrasive wear occurs also in mixing machines or lines for material transport, such as worm-conveyors. The experiment part of this paper analyses hard metal weld deposit dedicated for renovation of abrasive stressed surfaces. In order to prolong the service life of a blade disc in a mixing machine Kreis-Biogas-Dissolver, the technology of hard surfacing by an electric arc was used. Tested hard metal electrodes were applied on a steel tape class 11 373. To eliminate mixing with the base material, weld beads were applied in two layers. Firstly, the weld bead was visually analyzed on a binocular microscope. Further, weld bead as well as the base material was analyzed from the metallographic point of view, whose aim was to identify the structure of weld metal and the origin of microcracks in weld bead. Moreover, there was also measured microhardness of weld metal. Abrasive resistance was tested according to the norm ČSN 01 5084, which is an abrasive cloth test. As in the mixing process also erosion wear occurs, there was also processed a test on a Bond device simulating stress of test samples by loose abrasive particles. The abrading agents were formed by broken stones of 8–16 mm in size. Based on the results of the individual tests, the recommendation of usage hard metal electrodes for prolonging service life of machine parts will be made.

Standard Test Method to Determine Color Change and Staining Caused by Aircraft Maintenance Chemicals upon Aircraft Cabin Interior Hard Surfaces

CERN Document Server

American Society for Testing and Materials. Philadelphia

2001-01-01

1.1 This test method covers the determination of color change and staining from liquid solutions, such as cleaning or disinfecting chemicals or both, on painted metallic surfaces and nonmetallic surfaces of materials being used inside the aircraft cabin. The effects upon the exposed specimens are measured with the AATCC Gray Scale for Color Change and AATCC Gray Color Scale for Staining. Note 1—This test method is applicable to any colored nonmetallic hard surface in contact with liquids. The selected test specimens are chosen because these materials are present in the majority of aircraft cabin interiors. 1.2This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Fundamental measure theory for hard-sphere mixtures: a review

International Nuclear Information System (INIS)

Roth, Roland

2010-01-01

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

Review of intellectual assessment measures for children who are deaf or hard of hearing.

Science.gov (United States)

Reesman, Jennifer H; Day, Lori A; Szymanski, Christen A; Hughes-Wheatland, Roxanne; Witkin, Gregory A; Kalback, Shawn R; Brice, Patrick J

2014-02-01

Intellectual assessment of children who are deaf or hard of hearing presents unique challenges to the clinician charged with attempting to obtain an accurate representation of the child's skills. Selection of appropriate intellectual assessment instruments requires a working knowledge of the strengths and weaknesses of the measure and what changes in standardized administration might be necessary to accommodate for the needs of children who are deaf or hard of hearing. In the case of some available instruments, there is limited guidance and objective research available examining the performance of children who are deaf or hard of hearing. This review summarizes available information on widely used and most recent editions of intellectual assessment measures with special attention to guidance on accommodations, score interpretation, subtest selection and other test-specific considerations when assessing children who are deaf or hard of hearing. There is much opportunity for further inquiry in the field of intellectual assessment as it applies to children who are deaf or hard of hearing, as many measures have not been closely scrutinized for their appropriate use with this population. Clinicians must recognize inherent difficulties with intellectual assessment measures with children who are deaf or hard of hearing and issues in providing for an accessible and accurate administration of test items. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Hard disks with SCSI interface

CERN Document Server

Denisov, O Yu

1999-01-01

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

Studying Hardness Meter Spring Strength to Understand Hardness Distribution on Body Surfaces.

Science.gov (United States)

Arima, Yoshitaka

2017-10-01

For developing a hardness multipoint measurement system for understanding hardness distribution on biological body surfaces, we investigated the spring strength of the contact portion main axis of a biological tissue hardness meter (product name: PEK). We measured the hardness of three-layered sheets of six types of gel sheets (90 mm × 60 mm × 6 mm) constituting the acupuncture practice pads, with PEK measurements of 1.96 N, 2.94 N, 3.92 N, 4.90 N, 5.88 N, 6.86 N, 7.84 N, 8.82 N, and 9.81 N of the main axis spring strength. We obtained measurements 10 times for the gel sheets and simultaneously measured the load using a digital scale. We measured the hardness distribution of induration embedded and breast cancer palpation models, with a main axis with 1.96 N, 4.90 N, and 9.81 N spring strengths, to create a two-dimensional Contour Fill Chart. Using 4.90 N spring strength, we could obtain measurement loads of ≤3.0 N, and the mean hardness was 5.14 mm. This was close to the median of the total measurement range 0.0-10.0 mm, making the measurement range the largest for this spring strength. We could image the induration of the induration-embedded model regardless of the spring strength. Overall, 4.90 N spring strength was best suited for imaging cancer in the breast cancer palpation model. Copyright © 2017. Published by Elsevier B.V.

Classification of soft and hard impacts-Application to aircraft crash

International Nuclear Information System (INIS)

Koechlin, Pierre; Potapov, Serguei

2009-01-01

Before modeling an aircraft crash on a shield building of a nuclear power plant, it is very important to understand the physical phenomena and the structural behavior associated with this kind of impact. In the scientific literature, aircraft crash is classified as a soft impact, or as an impact of deformable missile. Nevertheless the existing classifications are not precise enough to be able to predict 'a priori' the structural response mode. The aim of this paper is to characterize very precisely what is a soft and a hard impact in the frame of aircraft crash on nuclear power plant. First the existing qualitative definition of soft and hard impact is quickly reviewed in order to introduce a new criterion to make a quantitative distinction between soft and hard impact. Then the experimental tests carried out during the last thirty years in the research field of aircraft crash are presented in the light of the new classification. The authors show that this characterization of soft and hard impacts has a real physical interest because it is linked to the failure mode for perforation: for soft impacts, perforation is the consequence of a shear plug breaking away and for hard impact it comes from local failure and projectile penetration. Moreover the boundary between soft and hard impact is the limit for the use of an impact force in an uncoupled computation of the impact

Assessing degradation of composite resin cements during artificial aging by Martens hardness.

Science.gov (United States)

Bürgin, Stefan; Rohr, Nadja; Fischer, Jens

2017-05-19

Aim of the study was to verify the efficiency of Martens hardness measurements in detecting the degradation of composite resin cements during artificial aging. Four cements were used: Variolink II (VL2), RelyX Unicem 2 Automix (RUN), PermaFlo DC (PDC), and DuoCem (DCM). Specimens for Martens hardness measurements were light-cured and stored in water at 37 °C for 1 day to allow complete polymerization (baseline). Subsequently the specimens were artificially aged by water storage at 37 °C or thermal cycling (n = 6). Hardness was measured at baseline as well as after 1, 4, 9 and 16 days of aging. Specimens for indirect tensile strength measurements were produced in a similar manner. Indirect tensile strength was measured at baseline and after 16 days of aging (n = 10). The results were statistically analyzed using one-way ANOVA (α = 0.05). After water storage for 16 days hardness was significantly reduced for VL2, RUN and DCM while hardness of PDC as well as indirect tensile strength of all cements were not significantly affected. Thermal cycling significantly reduced both, hardness and indirect tensile strength for all cements. No general correlation was found between Martens hardness and indirect tensile strength. However, when each material was analyzed separately, relative change of hardness and of indirect tensile strength revealed a strong linear correlation. Martens hardness is a sensible test method to assess aging of resin composite cements during thermal cycling that is easy to perform.

Induced spherococcoid hard wheat

International Nuclear Information System (INIS)

Yanev, Sh.

1981-01-01

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

Relative hardness measurement of soft objects by a new fiber optic sensor

Science.gov (United States)

Ahmadi, Roozbeh; Ashtaputre, Pranav; Abou Ziki, Jana; Dargahi, Javad; Packirisamy, Muthukumaran

2010-06-01

The measurement of relative hardness of soft objects enables replication of human finger tactile perception capabilities. This ability has many applications not only in automation and robotics industry but also in many other areas such as aerospace and robotic surgery where a robotic tool interacts with a soft contact object. One of the practical examples of interaction between a solid robotic instrument and a soft contact object occurs during robotically-assisted minimally invasive surgery. Measuring the relative hardness of bio-tissue, while contacting the robotic instrument, helps the surgeons to perform this type of surgery more reliably. In the present work, a new optical sensor is proposed to measure the relative hardness of contact objects. In order to measure the hardness of a contact object, like a human finger, it is required to apply a small force/deformation to the object by a tactile sensor. Then, the applied force and resulting deformation should be recorded at certain points to enable the relative hardness measurement. In this work, force/deformation data for a contact object is recorded at certain points by the proposed optical sensor. Recorded data is used to measure the relative hardness of soft objects. Based on the proposed design, an experimental setup was developed and experimental tests were performed to measure the relative hardness of elastomeric materials. Experimental results verify the ability of the proposed optical sensor to measure the relative hardness of elastomeric samples.

Local microstructures, Hardness and mechanical properties of a stainless steel pipe-welded joint

International Nuclear Information System (INIS)

Zhao Yongxiang; Gao Qing; Cai Lixun

2000-01-01

An experimental investigation is carefully performed into the local microstructures, hardness values and monotonic mechanical properties of the three zones (the base metal, heat affecting zone and weld metal) of 1Cr18Ni9Ti stainless steel pipe-welded joint. The local microstructures are observed by a metallurgical test and a surface replica technology, the local hardness values are measures by a random Vickers hardness test, and the local mechanical properties are characterized by the Ramberg-Osgood and modified Ramberg-Osgood stress-stain relations. The investigation reveals that there are significant differences of the three zones in the local microstructures, hardness values and monotonic mechanical properties, especially of the three zones in the local microstructure, hardness values and monotonic mechanical properties, especially of the weld metal. The weld metal exhibits the largest heterogeneity of local microstructures and monotonic mechanical properties, and the largest scatter of local hardness values. It is necessary to consider these difference and introduce the reliability method to model the scatter in the pipe analysis. In addition, it is verified that a columnar grain structure, which is made up of matrix-rich δ ferrite bands, can characterize the weld metal and the distance between the neighboring rich δ ferrite bands is an appropriate measurement of the columnar grain structure. This measurement is in accordance with the transition point between the microstructural short crack and physical small crack stages, which are generally used for characterizing the short fatigue crack behavior of materials. This indicates that the microstructure controls the fatigue damage character of the present material

Design of Vickers Hardness Loading Controller

Directory of Open Access Journals (Sweden)

Sihai Zhao

2014-09-01

Full Text Available Traditionally Vickers testing needs manual works, as a result, it will induce low precision and automatization. So this paper design a new type of loading controlling system, it is based on single chip computer 89S52, used PZT as the force generator in micro Vickers hardness testing. It primarily includes the designing of hardware, software of collecting data and PZT signals by AD667. This article has given the sketch of electrical circuit and controlling software, it also offers the experiment data. The experiments have showed that using this system can exactly control the loading results, and the average tolerance is less than 0.43 %.

The structure and formation of functional hard coatings: a short review

Directory of Open Access Journals (Sweden)

Diciuc Vlad

2017-01-01

Full Text Available Turning tools come in different shapes and sizes, geometry, base material and coating, according to their destination. They are widely used both for obtaining parts and for machinability tests. In this paper a short review about high-speed steel (HSS turning tools and their coatings is presented. Hard coatings formed on the tool material should be functional depending on the tool final application. Requirements for hard coatings and technological problems for layer formation on the real cutting tool are discussed.

Synergy of modeling processes in the area of soft and hard modeling

Directory of Open Access Journals (Sweden)

Sika Robert

2017-01-01

Full Text Available High complexity of production processes results in more frequent use of computer systems for their modeling and simulation. Process modeling helps to find optimal solution, verify some assumptions before implementation and eliminate errors. In practice, modeling of production processes concerns two areas: hard modeling (based on differential equations of mathematical physics and soft (based on existing data. In the paper the possibility of synergistic connection of these two approaches was indicated: it means hard modeling support based on the tools used in soft modeling. It aims at significant reducing the time in order to obtain final results with the use of hard modeling. Some test were carried out in the Calibrate module of NovaFlow&Solid (NF&S simulation system in the frame of thermal analysis (ATAS-cup. The authors tested output values forecasting in NF&S system (solidification time on the basis of variable parameters of the thermal model (heat conduction, specific heat, density. Collected data was used as an input to prepare soft model with the use of MLP (Multi-Layer Perceptron neural network regression model. The approach described above enable to reduce the time of production process modeling with use of hard modeling and should encourage production companies to use it.

Effect of heat-treatment on the hardness and mechanical properties of Boron Alloyed Steel

Directory of Open Access Journals (Sweden)

bin Khiyon Mohammad Raffik

2017-01-01

Full Text Available In an automotive industry, hot stamped, die quenched structural components have been widely used to provide extra protection against crash intrusion. Boron alloyed steel exhibit limited ductility, but it also promotes improvement in impact performance. This study analyzed the effect of cooling rate on the hardness and energy absorption. Self-quenched specimens were heated to 850°C and cooled in air of room temperature, water at room temperature and cold water. Vickers hardness test and tensile test was then carried out to analyze the effect of different quenching rate. Self-quenched specimens were compared to the properties of the die-quenched specimens obtained from commercial automobile body. Result shows that boron steel with the highest cooling rate has the highest value of hardness but low in strength.

2TB hard disk drive

CERN Multimedia

This particular object was used up until 2012 in the Data Centre. It slots into one of the Disk Server trays. Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes (link is external). They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks (link is external)." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.

Effect of different light curing units on Knoop hardness and temperature of resin composite

Directory of Open Access Journals (Sweden)

Guiraldo Ricardo

2009-01-01

Full Text Available Aim: To evaluate the influence of quartz tungsten halogen and plasma arc curing (PAC lights on Knoop hardness and change in polymerization temperature of resin composite. Materials and Methods: Filtek Z250 and Esthet X composites were used in the shade A3. The temperature increase was registered with Type-k thermocouple connected to a digital thermometer (Iopetherm 46. A self-cured polymerized acrylic resin base was built in order to guide the thermocouple and to support the dentin disk of 1.0 mm thickness obtained from bovine tooth. On the acrylic resin base, elastomer mold of 2.0 mm was adapted. The temperature increase was measured after composite light curing. After 24 h, the specimens were submitted to Knoop hardness test (HMV-2000, Shimadzu, Tokyo, Japan. Data were submitted to ANOVA and Tukey′s test (a = 0.05. Results: For both composites, there were no significant differences (P > 0.05 in the top surface hardness; however, PAC promoted statistically lower (P < 0.05 Knoop hardness number values in the bottom. The mean temperature increase showed no significant statistical differences (P > 0.05. Conclusion: The standardized radiant exposure showed no influence on the temperature increase of the composite, however, showed significant effect on hardness values.

Self-disinfecting Alginate vs Conventional Alginate: Effect on Surface Hardness of Gypsum Cast-An in vitro Study.

Science.gov (United States)

Madhavan, Ranjith; George, Navia; Thummala, Niharika R; Ravi, S V; Nagpal, Ajay

2017-11-01

For the construction of any dental prosthesis, accurate impressions are necessary. Hence, we undertook the present study to evaluate and compare the surface hardness of gypsum casts poured from impressions made using conventional alginate and self-disinfecting alginate. A total of 30 impressions of stainless steel die were made, out of which 15 impressions were made with conventional alginate and 15 were made with self-disinfecting alginate and poured using Type III dental stone. Thirty stone specimens were subjected for hardness testing. Data were analyzed using independent samples t-test to compare the mean surface hardness. Difference in surface hardness was statistically insignificant (p > 0.05). Surface hardness of gypsum casts poured using impressions made from self-disinfecting alginate and conventional alginates were comparable. Self-disinfecting alginates may be employed in clinical practice as safe and effective materials to overcome the infection control issues without compromising on the properties of the material.

Janka hardness using nonstandard specimens

Science.gov (United States)

David W. Green; Marshall Begel; William Nelson

2006-01-01

Janka hardness determined on 1.5- by 3.5-in. specimens (2×4s) was found to be equivalent to that determined using the 2- by 2-in. specimen specified in ASTM D 143. Data are presented on the relationship between Janka hardness and the strength of clear wood. Analysis of historical data determined using standard specimens indicated no difference between side hardness...

Effect of different light curing units on Knoop hardness and temperature of resin composite.

Science.gov (United States)

Guiraldo, Ricardo Danil; Consani, Simonides; Xediek Consani, Rafael Leonardo; Mendes, Wilson Batista; Lympius, Thais; Coelho Sinhoreti, Mario Alexandre

2009-01-01

To evaluate the influence of quartz tungsten halogen and plasma arc curing (PAC) lights on Knoop hardness and change in polymerization temperature of resin composite. Filtek Z250 and Esthet X composites were used in the shade A3. The temperature increase was registered with Type-k thermocouple connected to a digital thermometer (Iopetherm 46). A self-cured polymerized acrylic resin base was built in order to guide the thermocouple and to support the dentin disk of 1.0 mm thickness obtained from bovine tooth. On the acrylic resin base, elastomer mold of 2.0 mm was adapted. The temperature increase was measured after composite light curing. After 24 h, the specimens were submitted to Knoop hardness test (HMV-2000, Shimadzu, Tokyo, Japan). Data were submitted to ANOVA and Tukey's test (alpha = 0.05). For both composites, there were no significant differences (P > 0.05) in the top surface hardness; however, PAC promoted statistically lower (P 0.05). The standardized radiant exposure showed no influence on the temperature increase of the composite, however, showed significant effect on hardness values.

Determining the Effect of Material Hardness During the Hard Turning of AISI4340 Steel

Science.gov (United States)

Kambagowni, Venkatasubbaiah; Chitla, Raju; Challa, Suresh

2018-05-01

In the present manufacturing industries hardened steels are most widely used in the applications like tool design and mould design. It enhances the application range of hard turning of hardened steels in manufacturing industries. This study discusses the impact of workpiece hardness, feed and depth of cut on Arithmetic mean roughness (Ra), root mean square roughness (Rq), mean depth of roughness (Rz) and total roughness (Rt) during the hard turning. Experiments have been planned according to the Box-Behnken design and conducted on hardened AISI4340 steel at 45, 50 and 55 HRC with wiper ceramic cutting inserts. Cutting speed is kept constant during this study. The analysis of variance was used to determine the effects of the machining parameters. 3-D response surface plots drawn based on RSM were utilized to set up the input-output relationships. The results indicated that the feed rate has the most significant parameter for Ra, Rq and Rz and hardness has the most critical parameter for the Rt. Further, hardness shows its influence over all the surface roughness characteristics.

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

Science.gov (United States)

Ayyıldız, Simel; Soylu, Elif Hilal; Ide, Semra; Kılıç, Selim; Sipahi, Cumhur; Pişkin, Bulent; Gökçe, Hasan Suat

2013-11-01

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. 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 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). 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.

Hardness and Elastic Modulus of Titanium Nitride Coatings Prepared by Pirac Method

Science.gov (United States)

Wu, Siyuan; Wu, Shoujun; Zhang, Guoyun; Zhang, Weiguo

In the present work, hardness and elastic modulus of a titanium nitride coatings prepared on Ti6Al4V by powder immersion reaction-assisted coating (PIRAC) are tested and comparatively studied with a physical vapor deposition (PVD) TiN coating. Surface hardness of the PIRAC coatings is about 11GPa, much lower than that of PVD coating of 22GPa. The hardness distribution profile from surface to substrate of the PVD coatings is steeply decreased from ˜22GPa to ˜4.5GPa of the Ti6Al4V substrate. The PIRAC coatings show a gradually decreasing hardness distribution profile. Elastic modulus of the PVD coating is about 426GPa. The PIRAC coatings show adjustable elastic modulus. Elastic modulus of the PIRAC coatings prepared at 750∘C for 24h and that at 800∘C for 8h is about 234 and 293GPa, respectively.

Too hard to swallow: a secret secondary defence of an aposematic insect.

Science.gov (United States)

Wang, Lu-Yi; Huang, Wen-San; Tang, Hsin-Chieh; Huang, Lung-Chun; Lin, Chung-Ping

2018-01-25

Anti-predator strategies are significant components of adaptation in prey species. Aposematic prey are expected to possess effective defences that have evolved simultaneously with their warning colours. This study tested the hypothesis of the defensive function and ecological significance of the hard body in aposematic Pachyrhynchus weevils pioneered by Alfred Russel Wallace nearly 150 years ago. We used predation trials with Japalura tree lizards to assess the survivorship of 'hard' (mature) versus 'soft' (teneral) and 'clawed' (intact) versus 'clawless' (surgically removed) weevils. The ecological significance of the weevil's hard body was evaluated by assessing the hardness of the weevils, the local prey insects, and the bite forces of the lizard populations. The existence of toxins or deterrents in the weevil was examined by gas chromatography-mass spectrometry (GC-MS). All 'hard' weevils were instantly spat out after being bitten once and survived attacks by the lizards. In contrast, the 'soft' weevils were chewed and subsequently swallowed. The results were the same regardless of the presence or absence of the weevil's tarsal claws. The hardness of 'hard' Pachyrhynchus weevils was significantly higher than the average hardness of other prey insects in the same habitat and the mean bite forces of the local lizards. The four candidate compounds of the weevil identified by GC-MS had no known toxic or repellent functions against vertebrates. These results reveal that the hardness of aposematic prey functions as an effective secondary defence, and they provide a framework for understanding the spatio-temporal interactions between vertebrate predators and aposematic insect prey. © 2018. Published by The Company of Biologists Ltd.

Peer Support for the Hardly Reached: A Systematic Review.

Science.gov (United States)

Sokol, Rebeccah; Fisher, Edwin

2016-07-01

Health disparities are aggravated when prevention and care initiatives fail to reach those they are intended to help. Groups can be classified as hardly reached according to a variety of circumstances that fall into 3 domains: individual (e.g., psychological factors), demographic (e.g., socioeconomic status), and cultural-environmental (e.g., social network). Several reports have indicated that peer support is an effective means of reaching hardly reached individuals. However, no review has explored peer support effectiveness in relation to the circumstances associated with being hardly reached or across diverse health problems. To conduct a systematic review assessing the reach and effectiveness of peer support among hardly reached individuals, as well as peer support strategies used. Three systematic searches conducted in PubMed identified studies that evaluated peer support programs among hardly reached individuals. In aggregate, the searches covered articles published from 2000 to 2015. Eligible interventions provided ongoing support for complex health behaviors, including prioritization of hardly reached populations, assistance in applying behavior change plans, and social-emotional support directed toward disease management or quality of life. Studies were excluded if they addressed temporally isolated behaviors, were limited to protocol group classes, included peer support as the dependent variable, did not include statistical tests of significance, or incorporated comparison conditions that provided appreciable social support. We abstracted data regarding the primary health topic, categorizations of hardly reached groups, program reach, outcomes, and strategies employed. We conducted a 2-sample t test to determine whether reported strategies were related to reach. Forty-seven studies met our inclusion criteria, and these studies represented each of the 3 domains of circumstances assessed (individual, demographic, and cultural-environmental). Interventions

A synthetic dataset for evaluating soft and hard fusion algorithms

Science.gov (United States)

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

2011-06-01

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

Characterization and Tribological Properties of Hard Anodized and Micro Arc Oxidized 5754 Quality Aluminum Alloy

Directory of Open Access Journals (Sweden)

M. Ovundur

2015-03-01

Full Text Available This study was initiated to compare the tribological performances of a 5754 quality aluminum alloy after hard anodic oxidation and micro arc oxidation processes. The structural analyses of the coatings were performed using XRD and SEM techniques. The hardness of the coatings was determined using a Vickers micro-indentation tester. Tribological performances of the hard anodized and micro arc oxidized samples were compared on a reciprocating wear tester under dry sliding conditions. The dry sliding wear tests showed that the wear resistance of the oxide coating generated by micro arc oxidation is remarkably higher than that of the hard anodized alloy.

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

Energy Technology Data Exchange (ETDEWEB)

Paulus, Wilfred [Universiti Kebangsaan Malaysia, Bangi, 43600 Kajang, Selangor (Malaysia); Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Rahman, Irman Abdul; Jalar, Azman; Kamil, Insan; Bakar, Maria Abu [Universiti Kebangsaan Malaysia, Bangi, 43600 Kajang, Selangor (Malaysia); Yusoff, Wan Yusmawati Wan [Universiti Pertahanan Nasional Malaysia, Kem Sg. Besi, 57000 Kuala Lumpur (Malaysia)

2015-09-25

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.

Total-dose hardness assurance for low earth orbit

International Nuclear Information System (INIS)

Maurer, R.H.; Suter, J.J.

1987-01-01

The Low Earth Orbit radiation environment has two significant characteristics that make laboratory simulation exposures difficult: (1) a low dose rate and (2) many cycles of low dose accumulation followed by dose-free annealing. Hardness assurance considerations for this environment are discussed and related to data from the testing of Advanced Low Power Schottky and High-speed CMOS devices

Hard-sphere fluid adsorbed in an annular wedge: The depletion force of hard-body colloidal physics

Science.gov (United States)

Herring, A. R.; Henderson, J. R.

2007-01-01

Many important issues of colloidal physics can be expressed in the context of inhomogeneous fluid phenomena. When two large colloids approach one another in solvent, they interact at least partly by the response of the solvent to finding itself adsorbed in the annular wedge formed between the two colloids. At shortest range, this fluid mediated interaction is known as the depletion force/interaction because solvent is squeezed out of the wedge when the colloids approach closer than the diameter of a solvent molecule. An equivalent situation arises when a single colloid approaches a substrate/wall. Accurate treatment of this interaction is essential for any theory developed to model the phase diagrams of homogeneous and inhomogeneous colloidal systems. The aim of our paper is a test of whether or not we possess sufficient knowledge of statistical mechanics that can be trusted when applied to systems of large size asymmetry and the depletion force in particular. When the colloid particles are much larger than a solvent diameter, the depletion force is dominated by the effective two-body interaction experienced by a pair of solvated colloids. This low concentration limit of the depletion force has therefore received considerable attention. One route, which can be rigorously based on statistical mechanical sum rules, leads to an analytic result for the depletion force when evaluated by a key theoretical tool of colloidal science known as the Derjaguin approximation. A rival approach has been based on the assumption that modern density functional theories (DFT) can be trusted for systems of large size asymmetry. Unfortunately, these two theoretical predictions differ qualitatively for hard sphere models, as soon as the solvent density is higher than about 2/3 that at freezing. Recent theoretical attempts to understand this dramatic disagreement have led to the proposal that the Derjaguin and DFT routes represent opposite limiting behavior, for very large size asymmetry

Comprehension of Written Grammar Test: Reliability and Known-Groups Validity Study With Hearing and Deaf and Hard-of-Hearing Students.

Science.gov (United States)

Cannon, Joanna E; Hubley, Anita M; Millhoff, Courtney; Mazlouman, Shahla

2016-01-01

The aim of the current study was to gather validation evidence for the Comprehension of Written Grammar (CWG; Easterbrooks, 2010) receptive test of 26 grammatical structures of English print for use with children who are deaf and hard of hearing (DHH). Reliability and validity data were collected for 98 participants (49 DHH and 49 hearing) in Grades 2-6. The objectives were to: (a) examine 4-week test-retest reliability data; and (b) provide evidence of known-groups validity by examining expected differences between the groups on the CWG vocabulary pretest and main test, as well as selected structures. Results indicated excellent test-retest reliability estimates for CWG test scores. DHH participants performed statistically significantly lower on the CWG vocabulary pretest and main test than the hearing participants. Significantly lower performance by DHH participants on most expected grammatical structures (e.g., basic sentence patterns, auxiliary "be" singular/plural forms, tense, comparatives, and complementation) also provided known groups evidence. Overall, the findings of this study showed strong evidence of the reliability of scores and known group-based validity of inferences made from the CWG. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Analysis of 2 patients with occupational hard mental lung disease].

Science.gov (United States)

Ding, Bangmei; Ding, Lu; Yu, Bin; Fan, Cunhua; Han, Lei; Hu, Jinmei; Zhu, Baoli

2015-01-01

We sought to master the clinical characteristics and prognosis of hard mental lung disease, improving this disease's diagnosis and treatment quality. We recruited two suspected patients with hard mental lung disease and collected their occupational history, examination results of occupational health, and past medical records. By virtue of laboratory tests, high Kv chest radiography, CT and HRCT of chest, fiberoptic bronchoscopy and ECG examination, diagnostic report was synthesized respectively by respiratory physicians and pathologist from three different agencies. Then the report was submitted to diagnosis organizations of occupational disease, and diagnostic conclusion of occupational disease was drawn after discussion by at least three diagnosticians of occupational disease. We found that both of the two suspected patients were exposed to dusts of hard metal, and length of exposure service ranged from 8 to 9 years. Clinical manifestations were dominated by dry cough, wheezing after activities, and pathological manifestation was characteristic giant cell interstitial pneumonia. The prognosis and outcome of the disease were different. According to exact occupational exposure history, clinical manifestations, combined with the results of high Kv chest radiography, CT of chest and pathological manifestation, it can be diagnosed with hard mental lung disease.

Effects of the bleaching procedures on enamel micro-hardness: Plasma Arc and diode laser comparison.

Science.gov (United States)

Nematianaraki, Saeid; Fekrazad, Reza; Naghibi, Nasim; Kalhori, Katayoun Am; Junior, Aldo Brugnera

2015-10-02

One of the major side effects of vital bleaching is the reduction of enamel micro-hardness. The purpose of this study was to evaluate the influence of two different bleaching systems, Plasma Arc and GaAlAs laser, on the enamel micro-hardness. 15 freshly extracted human third molars were sectioned to prepare 30 enamel blocks (5×5 mm). These samples were then randomly divided into 2 groups of 15 each (n=15): a plasma arc bleaching group (: 350-700 nm) + 35% Hydrogen Peroxide whitening gel and a laser bleaching group (GaAlAs laser, λ: 810 nm, P: 10 W, CW, Special Tip) + 35% Hydrogen Peroxide whitening gel. Samples were subjected to the Vickers micro-hardness test (VHN) at a load of 50 g for 15s before and after treatment. Data were statistically analyzed by a Mann-Whitney test (p≤0.05). In the GaAlAs laser group, the enamel micro-hardness was 618.2 before and was reduced to 544.6 after bleaching procedures. In the plasma arc group, the enamel micro-hardness was 644.8 before and 498.9 after bleaching. Although both techniques significantly reduced VHN, plasma arc bleaching resulted in a 22.62% reduction in VHN for enamel micro-hardness, whereas an 11.89% reduction in VHN was observed for laser bleaching; this difference is statistically significant (plaser than with the plasma arc. Therefore GaAlAs laser bleaching has fewer harmful effects than plasma arc in respect to enamel micro-hardness reduction.

Shutdown and degradation: Space computers for nuclear application, verification of radiation hardness. Final report

International Nuclear Information System (INIS)

Eichhorn, E.; Gerber, V.; Schreyer, P.

1995-01-01

(1) Employment of those radiation hard electronics which are already known in military and space applications. (2) The experience in space-flight shall be used to investigate nuclear technology areas, for example, by using space electronics to prove the range of applications in nuclear radiating environments. (3) Reproduction of a computer developed for telecommunication satellites; proof of radiation hardness by radiation tests. (4) At 328 Krad (Si) first failure of radiation tolerant devices with 100 Krad (Si) hardness guaranteed. (5) Using radiation hard devices of the same type you can expect applications at doses of greater than 1 Mrad (Si). Electronic systems applicable for radiation categories D, C and lower part of B for manipulators, vehicles, underwater robotics. (orig.) [de

Bulk sensitive hard x-ray photoemission electron microscopy

Energy Technology Data Exchange (ETDEWEB)

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

2014-11-15

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

Surface hardness of hybrid ionomer cement after immersion in antiseptic solution

Directory of Open Access Journals (Sweden)

Anita Yuliati

2006-06-01

Full Text Available Hybrid ionomer cement or resin modified glass ionomer cement is a developed form of conventional glass ionomer cement. This hybrid ionomer cement can be eroded if in direct contact with acid solution which will affect surface hardness. The aim of this study is to learn surface hardness of hybrid ionomer cement after immersion in methyl salicylate 0.06% (pH 3.6 and povidon iodine 1% (pH 2.9 solution. Sample of hybrid ionomer cement with 5 mm diameter and 3 mm thickness was immersed in sterile aquadest solution (control, methyl salicylate pH 3.6, povidon iodine pH 2.9 for 1 minute, 7 and 14 minutes. Surface hardness was measured with Micro Vickers Hardness Tester. The obtained data was analyzed statistically with ANOVA followed by LSD test. The result of hybrid ionomer cement after immersion in sterile aquadest, methyl salicylate 0.06% pH 3.6 and povidon iodine 1% pH 2.9 for one minute, showed no significant difference; while immersion for 7 and 14 minutes showed a significant difference. The conclusion states that hybrid ionomer cement after 14 minutes immersion in povidon iodine 1% pH 2.9 has the lowest surface hardness.

The effect of three whitening oral rinses on enamel micro-hardness.

Science.gov (United States)

Potgieter, E; Osman, Y; Grobler, S R

2014-05-01

The purpose of this study was to determine the effect on human enamel micro-hardness of three over-the-counter whitening oral rinses available in South Africa. Enamel fragments were gathered into three groups of 15 each. One group was exposed to Colgate Plax Whitening Blancheur, the second group to White Glo 2 in 1 and the third to Plus White, in each case for periods recommended by the respective manufacturers. Surface micro-hardness of all groups was measured before and after a 14 day treatment period. pH levels of the oral rinses were also determined with a combination pH electrode. Pre- and post- treatment data were analysed by the Wilcoxon Signed Rank Sum Test. According to the micro-hardness values no significant (p > 0.05) enamel damage was found as a result of treatment. However, it was observed that Colgate Pax and White Glo decreased the enamel hardness, an early sign of enamel damage, while Plus White showed a small increase in hardness. The three whitening oral rinses on the South African market do not damage the tooth enamel significantly when used as recommended by the manufacturers. However, extending the contact period and increasing the frequency of application might lead to damage of enamel.

Development of hard-seal gate valve and fast shutter for JT-60 neutral beam injectors

International Nuclear Information System (INIS)

Kuribayashi, S.; Minami, M.; Matsuoka, T.; Takeshita, K.; Morita, H.; Kuriyama, M.; Matsuda, S.; Shirakata, H.

1983-01-01

A 600 mm hard-seal valve and a fast shutter for the JT-60 Neutral Beam Injector were developed. The 600 mm hard-seal gate valve was fabricated and tested for 500 cycles at various temperatures of up to 250 0 C. In consequence, requirements of the endurance and vacuum tightness were satisfied. Major components of the fast shutter, i.e., swing action bellows and a high-speed pneumatic cylinder, were tested for 30,000 cycles, and their reliability was confirmed. Then the fast shutter was fabricated and tested. The test result indicated that the fast shutter fully satisfied the requirements of the molecular gas flow conductance and opening/closing speed. (author)

An investigation into the mechanical and tribological properties of plasma electrolytic oxidation and hard-anodized coatings on 6082 aluminum alloy

International Nuclear Information System (INIS)

Malayoglu, Ugur; Tekin, Kadir C.; Malayoglu, Ufuk; Shrestha, Suman

2011-01-01

Highlights: → Mechanical properties of PEO and anodised coatings were studied using ultra-micro hardness tester. → Elastic modulus and hardness of the PEO coating were found much higher than those of the anodised coating. → Improved sliding wear of PEO coating is due to presence of hard α and γ-Al 2 O 3 phases. - Abstract: A ceramic coating on AA6082 aluminum alloy prepared by plasma electrolytic oxidation (PEO) has been studied and compared against a sulphuric acid hard-anodized coating on the same alloy. Surface morphology and microstructures of the coatings have been examined by scanning electron microscopy. X-ray diffraction is used to determine the phase composition of the coatings. The adhesion strength of the coatings has been evaluated using a scratch test method. The coating's mechanical properties such elastic modulus and hardness data have been generated using a dynamic ultra-microhardness tester. Sliding wear tests with different loading rates are performed on the coatings in order to assess their wear resistance. Test results show that the PEO treated samples exhibit significantly better mechanical properties compared to hard anodized samples. The elastic modulus and hardness of the PEO coating are 2-3 times greater than of the hard anodized coating and subsequently, an improved wear resistance of the PEO coating has been achieved. The mechanical properties of the coatings and their relations to their tribological performance are discussed.

Nonvolatile Rad-Hard Holographic Memory

Science.gov (United States)

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.

Recent results on the development of radiation-hard diamond detectors

CERN Document Server

Conway, J S; Bauer, C; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Dabrowski, W; Da Graca, J; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Jamieson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernicka, Manfred; Peitz, A; Pirollo, S; Plano, R; Polesello, P; Prawer, S; Pretzl, Klaus P; Procario, M; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Russ, J; Schnetzer, S; Sciortino, S; Somalwar, S V; Speziali, V; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R; Thomson, G B; Trawick, M; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; White, C; Ziock, H J; Zöller, M

1999-01-01

Charged particle detectors made from chemical vapor deposition (CVD) diamond have radiation hardness greatly exceeding that of silicon- based detectors. The CERN-based RD42 Collaboration has developed and tested CVD diamond microstrip and pixel detectors with an eye to their application in the intense radiation environment near the interaction region of hadron colliders. This paper presents recent results from tests of these detectors. (4 refs).

On scale dependence of hardness

International Nuclear Information System (INIS)

Shorshorov, M.Kh.; Alekhin, V.P.; Bulychev, S.I.

1977-01-01

The concept of hardness as a structure-sensitive characteristic of a material is considered. It is shown that in conditions of a decreasing stress field under the inventor the hardness function is determined by the average distance, Lsub(a), between the stops (fixed and sessile dislocations, segregation particles, etc.). In the general case, Lsub(a) depends on the size of the impression and explains the great diversity of hardness functions. The concept of average true deformation rate on depression is introduced

Hardness Assurance Techniques for New Generation COTS Devices

Science.gov (United States)

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

1996-01-01

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

Evaluation of variables which affect the hardness of nickel plate deposited from watts-type baths

International Nuclear Information System (INIS)

Petit, G.S.; Wright, R.R.; Neff, W.A.

1976-01-01

In the course of the Cascade Improvement Program, many component equipment parts will be electroplated with nickel for corrosion protection. The maximum hardness which will be acceptable in the electroplated deposit is specified in Union Carbide's Job Specification JS-1396, Revision 3, entitled Electroplated Nickel Coatings on Steel Parts. The hardness specification is intended primarily as a control over both organic and inorganic impurities in the deposit. This report covers a study evaluating several of the numerous controllable variables which influence the hardness of the nickel plate deposited from a Watts-type bath. The variables tested were: 1) bath composition, 2) pH, 3) current density, 4) anode-cathode area ratio, and 5) bath temperature. Within the tested ranges of the variables studied, the pH and current density had the most influence on the plate hardness. The softest deposit was obtained with a bath pH of 1.5, a current density of 30 to 40 amperes/square foot, and with the anode-cathode area ratio in the range of 3:1 to 1:1

Rolling contact fatigue of low hardness steel for slewing ring application

Science.gov (United States)

Knuth, Jason A.

This thesis discusses the rolling contact fatigue of steel utilized in anti-friction bearings, also referred to as slewing bearings. These slewing bearings are utilized in cranes, excavators, wind turbines and other similar applications. Five materials composed of two different material types were tested. The two material types were high carbon steel and medium carbon alloy steel. The test specimens were processed from forged rolled rings. Two machines were evaluated a ZF-RCF and 3-Ball test machine. The evaluation was to determine which machine can best simulate the application in which the slewing bearing is utilized. Initially, each specimen will be pretested to determine the appropriate testing direction from within the forged rolled rings. Pretesting is needed in order to establish consistent failure modes between samples. The primary goal of the test is to understand the life differences and failure modes between high carbon steel and medium carbon alloy steel. The high carbon steel ring was cut into two sections, one of which was stress relieved and the other was quenched and tempered. The medium carbon alloy steel was cut into three sections, all of which were quenched and tempered to different hardness levels. The test program was dynamically adjusted based upon the previous sample's life and load. An S-N curve was then established from the 5 materials tested at two target loads. The samples were run until the first sign of a crack was detected by an eddy current. At the completion of the rolling contact test, select sample's microstructure was evaluated for crack initiation location. The selected samples were divided into four groups which represent different maximum shear stress levels. These samples displayed indications of material deformation in which the high carbon steel experienced an increased amount of cold work when compared to medium carbon alloy steel. The life of the high carbon steel was nearly equivalent to the expected life of the medium

Effect of plasma nitriding time on surface properties of hard chromium electroplated AISI 1010 steel

Energy Technology Data Exchange (ETDEWEB)

Kocabas, Mustafa [Yildiz Technical Univ., Istanbul (Turkey). Metallurgical and Materials Engineering Dept.; Danisman, Murat [Gedik Univ., Istanbul (Turkey). Electrical and Electronic Engineering Dept.; Cansever, Nurhan [Yildiz Technical Univ., Istanbul (Turkey); Uelker, Suekrue [Afyon Kocatepe Univ. (Turkey). Dept. of Mechanical Engineering

2015-06-01

Properties of steel can be enhanced by surface treatments such as coating. In some cases, further treatments such as nitriding can also be used in order to get even better results. In order to investigate the properties of nitride layer on hard Cr coated AISI 1010 steel, substrates were electroplated to form hard Cr coatings. Then hard Cr coatings were plasma nitrided at 700 C for 3 h, 5 h and 7 h and nitride phases on the coatings were investigated by X-ray diffraction analysis. The layer thickness and surface properties of nitride films were investigated by scanning electron microscopy. The hardness and adhesion properties of Cr-N phases were examined using nano indentation and Daimler-Benz Rockwell C adhesion tests. The highest measured hardness was 24.1 GPa and all the three samples exhibited poor adhesion.

Effect of plasma nitriding time on surface properties of hard chromium electroplated AISI 1010 steel

International Nuclear Information System (INIS)

Kocabas, Mustafa; Uelker, Suekrue

2015-01-01

Properties of steel can be enhanced by surface treatments such as coating. In some cases, further treatments such as nitriding can also be used in order to get even better results. In order to investigate the properties of nitride layer on hard Cr coated AISI 1010 steel, substrates were electroplated to form hard Cr coatings. Then hard Cr coatings were plasma nitrided at 700 C for 3 h, 5 h and 7 h and nitride phases on the coatings were investigated by X-ray diffraction analysis. The layer thickness and surface properties of nitride films were investigated by scanning electron microscopy. The hardness and adhesion properties of Cr-N phases were examined using nano indentation and Daimler-Benz Rockwell C adhesion tests. The highest measured hardness was 24.1 GPa and all the three samples exhibited poor adhesion.

Evaluation of Treatments to Reduce Hardness of Agave americana Core

Directory of Open Access Journals (Sweden)

José A. Ramírez

2006-01-01

Full Text Available Agave americana contains inulin as storage carbohydrate. Therefore, agave is interesting to be used for the extraction of inulin by pressing. The yield of the process is low due to the high hardness of the core. The objective of this work was to evaluate pretreatments to reduce the hardness in the process of obtaining inulin by pressing. Treatments with water, sulphuric acid 1 % (by mass or sodium hydroxide 1 % (by mass were tested and optimized. The pretreatment of the core of A. americana with sulphuric acid 1 % allowed the reduction of hardness from 30 000 g to 2000 g of breaking force. The mathematical model obtained predicts an optimum processing at 84 °C during 75 min. The treatment with sulphuric acid 1 % also allows white core of A. americana to be obtained, while the other treatments provide yellow core. These results open a good alternative to obtain value added products from this resource.

Manufacturing technology development of plasma/ion nitriding for improvement of hardness of machine components and tools

International Nuclear Information System (INIS)

Suprapto; Tjipto Sujitno; Saminto

2015-01-01

The manufacturing technology development of plasma/ion nitriding to improve of hardness of machine components and tools has been done. The development of this technology aims to improve device performance plasma nitriding double chamber and conducted with the addition of thermal radiation shield. Testing was done by testing for preheating operation (start-up), test operation for conditions nitriding and test for nitriding process. The results show that: the plasma nitriding device can be operated for nitriding process at the temperature of about 500 °C for 6 hours, using the thermal radiation shield obtained outside wall temperature of about 65 °C and shorten start-up time to about 60 minutes. The use of thermal radiation shield can also improve the efficiency of the electric power supply and increase the operating temperature for nitriding process. Test for nitriding obtained increase of hardness 1.33 times for the original camshaft (genuine parts) and 1.8 times for the imitation camshaft (imitation parts), the results are compared with after the tempering process at a temperature of 600 °C. For sample SS 304 was 2.45 times compared with before nitrided These results indicate that the development of manufacturing technology of plasma/ion nitriding to increase hardness of machine components and tools have been successfully able to increase the hardness, although still need to be optimized. Besides that, these devices can be developed to use for the process of carburizing and carbonitriding. (author)

Hard-hat day

CERN Multimedia

2003-01-01

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

System tests of radiation hard optical links for the ATLAS semiconductor tracker

International Nuclear Information System (INIS)

Charlton, D.G.; Dowell, J.D.; Homer, R.J.; Jovanovic, P.; Kenyon, I.R.; Mahout, G.; Shaylor, H.R.; Wilson, J.A.; Rudge, A.; Fopma, J.; Mandic, I.; Nickerson, R.B.; Shield, P.; Wastie, R.; Weidberg, A.R.; Eek, L.-O.; Go, A.; Lund-Jensen, B.; Pearce, M.; Soederqvist, J.; Morrissey, M.; White, D.J.

2000-01-01

A prototype optical data and Timing, Trigger and Control transmission system based on LEDs and PIN-diodes has been constructed. The system would be suitable in terms of radiation hardness and radiation length for use in the ATLAS SemiConductor Tracker. Bit error rate measurements were performed for the data links and for the links distributing the Timing, Trigger and Control data from the counting room to the front-end modules. The effects of cross-talk between the emitters and receivers were investigated. The advantages of using Vertical Cavity Surface Emitting Lasers (VCSELs) instead of LEDs are discussed

[Determination of Hard Rate of Alfalfa (Medicago sativa L.) Seeds with Near Infrared Spectroscopy].

Science.gov (United States)

Wang, Xin-xun; Chen, Ling-ling; Zhang, Yun-wei; Mao, Pei-sheng

2016-03-01

Alfalfa (Medicago sativa L.) is the most commonly grown forage crop due to its better quality characteristics and high adaptability in China. However, there was 20%-80% hard seeds in alfalfa which could not be identified easily from non hard seeds which would cause the loss of seed utilization value and plant production. This experiment was designed for 121 samples of alfalfa. Seeds were collected according to different regions, harvested year and varieties. 31 samples were artificial matched as hard rates ranging from 20% to 80% to establish a model for hard seed rate by near infrared spectroscopy (NIRS) with Partial Least Square (PLS). The objective of this study was to establish a model and to estimate the efficiency of NIRS for determining hard rate of alfalfa seeds. The results showed that the correlation coefficient (R2(cal)) of calibration model was 0.981 6, root mean square error of cross validation (RMSECV) was 5.32, and the ratio of prediction to deviation (RPD) was 3.58. The forecast model in this experiment presented the satisfied precision. The proposed method using NIRS technology is feasible for identification and classification of hard seed in alfalfa. A new method, as nondestructive testing of hard seed rate, was provided to theoretical basis for fast nondestructive detection of hard seed rates in alfalfa.

Hard And Soft QCD Physics In ATLAS

Directory of Open Access Journals (Sweden)

Adomeit Stefanie

2014-04-01

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

Development of a hard microcontroller

International Nuclear Information System (INIS)

Measel, P.R.; Sivo, L.L.; Quilitz, W.E.; Davidson, T.K.

1976-01-01

The applicability of commercially available microprocessors to certain systems requiring radiation survival was assessed. A microcontroller was designed and built to perform a monitor and control function of military operational ground equipment, and demonstrated to exceed the radiation hardness goal. The preparation of the microcontroller module required hardware and software design, selection of LSI and other piece part types, development of piece part and module electrical and radiation test techniques, and the performance of radiation tests on the LSI piece parts and the completed module. The microcontroller has a 16-bit central processor unit, a 4096 word read only memory, and a 256 word read-write memory. The module has circumvention circuitry, including a PIN diode radiation detector. The processor device used was the MMI 6701 T 2 L Schottky bipolar 4-bit slice. Electrical exerciser circuits were developed for in-situ electrical testing of microprocessors and memories during irradiation. A test program was developed for a Terradyne J283 microcircuit tester for more complete electrical characterization of the MMI 6701 microprocessor. A simple self-test algorithm was used in the microcontroller for performance testing during irradiation. For the operational demonstration of the microcontroller a TI 960A minicomputer was used to provide the required complex inputs to the module and verify the module outputs

Nanolaminated TiN/Mo2N hard multilayer coatings

International Nuclear Information System (INIS)

Martev, I N; Dechev, D A; Ivanov, N P; Uzunov, T S D; Kashchieva, E P

2010-01-01

The paper presents results on the synthesis of hard multilayer coatings consisting of titanium nitride and molybdenum nitride thin films with thickness of several nm. The TiN and Mo 2 N films were successively deposited by reactive DC magnetron sputtering. These multilayer structures were investigated by Auger electron spectroscopy (AES), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), cross-section scanning electron microscopy (CSSEM) and cross-section electron probe microanalysis (CSEPMA). The mechanical properties of the multilayer coatings, namely, hardness, Young's modulus and the coefficient of plastic deformation were measured. The adhesion was evaluated by the Rockwell-C-impact test. Coatings with different total thickness were examined with respect to adhesion to substrates of tool materials.

[Domestic water hardness and prevalence of atopic eczema in Castellon (Spain) school children].

Science.gov (United States)

Arnedo-Pena, Alberto; Bellido-Blasco, Juan; Puig-Barbera, Joan; Artero-Civera, Adrián; Campos-Cruañes, Joan Baptista; Pac-Sa, M Rosario; Villamarín-Vázquez, Jose Luis; Felis-Dauder, Carlos

2007-01-01

Water hardness has been associated with atopic eczema (AE) prevalence in two epidemiologic studies carried out on schoolchildren in England and Japan. To estimate the association between the prevalence of AE and domestic water hardness. The prevalence of AE was obtained from The International Study of Asthma and Allergies in Childhood, carried out in six towns in the province of Castellón on schoolchildren 6-7 and 13-14 years of age, using a standard questionnaire in 2002. Three zones were defined according to domestic water hardness of the six study localities: 300 mg/l. A logistic regression analysis was performed. The lifetime prevalence of AE in schoolchildren 6-7 years of age was higher with the increment of water hardness, 28.6, 30.5 and 36.5% respectively for each zone; between zone 1 and zone 3, the adjusted odds ratios (ORa) were 1.58 (95% Confidence Intervals [CI] 1.04-2.39) (adjusted tendency test p=0.034). Prevalence of symptoms of AE within the past year were 4.7, 4.5, and 10.4%, respectively by zone; between zone 1 and zone 3, the ORa was 2.29 (95% CI 1.19-4.42) (adjusted tendency test p=0,163). For 13-14 year-old schoolchildren, tendencies to lifetime prevalence of AE at any time or in the past year were not significant. This study suggests that in 6-7 year-old schoolchildren, water hardness in the area where they live has some relevance to the development of the disease.

Relationship between nickel and cobalt sensitization in hard metal workers

Energy Technology Data Exchange (ETDEWEB)

Rystedt, I; Fischer, T

1983-05-01

Eight hundred fifty-three hard metal workers were examined and patch tested with 20 substances from their environment, including nickel and cobalt. Nickel sensitivity was found in 2 men and 38 women. 88% of the nickel-sensitive individuals had developed a jewelry dermatitis prior to employment in the hard metal industry or before the appearance of hand eczema. 29% of the hard metal workers gave a history of slight irritant dermatitis. In the nickel sensitized group, 40% had had severe hand eczema which generally appeared 6-12 months after starting employment. In 25% of the cases, nickel sensitive individuals developed cobalt allergy, compared with 5% in the total population investigated. Most facts indicate that nickel sensitivity and irritant hand eczema precede cobalt sensitization. Hard metal workers with simultaneous nickel and cobalt sensitivity had a more severe hand eczema than those with isolated cobalt or nickel sensitivity or only irritant dermatitis. 64% of the female population had pierced ear lobes. Among the nickel allergic women, 95% had pierced ear lobes. The use of earrings containing nickel after piercing is strongly suspected of being the major cause of nickel sensitivity. Piercing at an early age seems to increase the risk of incurring nickel sensitivity.

Impact of water hardness on energy consumption of geyser heating ...

African Journals Online (AJOL)

Therefore, the Eskom Research, Testing, and Development Business Unit embarked on a study to examine total water hardness as a chemical parameter that may impact the power consumption of electrical geyser heating elements. An accelerated scaling method was developed to lime-scale the geyser heating elements ...

Performance And Radiation Hardness Of The Atlas/sct Detector Module

CERN Document Server

Eklund, L

2003-01-01

The ATLAS experiment is a general purpose experiment being constructed at the Large Hadron Collider (LHC) at FERN, Geneva. ATLAS is designed to exploit the full physics potential of LHC, in particular to study topics concerning the Higgs mechanism, Super-symmetry and CP violation. The cross sections for the processes under study are extremely small, requiring very high luminosity colliding beams. The Semiconductor Tracker (SCT) is an essential part of the Inner Detector tracking system of ATLAS. The active elements of the SCT is 4088 detector modules, tiled on four barrel cylinders and eighteen endcap disks. As a consequence of the high luminosity, the detector modules will operate in a harsh radiation environment. This thesis describes work concerning radiation hardness, beam test performance and methods for production testing of detector modules. The radiation hardness studies have been focused on the electrical performance of the front-end ASIC and the detector module. The results have identified features ...

Effect of Heating Time on Hardness Properties of Laser Clad Gray Cast Iron Surface

Science.gov (United States)

Norhafzan, B.; Aqida, S. N.; Mifthal, F.; Zulhishamuddin, A. R.; Ismail, I.

2018-03-01

This paper presents effect of heating time on cladded gray cast iron. In this study, the effect of heating time on cladded gray cast iron and melted gray cast iron were analysed. The gray cast iron sample were added with mixed Mo-Cr powder using laser cladding technique. The mixed Mo and Cr powder was pre-placed on gray cast iron surface. Modified layer were sectioned using diamond blade cutter and polish using SiC abrasive paper before heated. Sample was heated in furnace for 15, 30 and 45 minutes at 650 °C and cool down in room temperature. Metallographic study was conduct using inverted microscope while surface hardness properties were tested using Wilson hardness test with Vickers scale. Results for metallographic study showed graphite flakes within matrix of pearlite. The surface hardness for modified layer decreased when increased heating time process. These findings are significant to structure stability of laser cladded gray cast iron with different heating times.

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

International Nuclear Information System (INIS)

Holleck, H.; Thuemmler, F.

1979-07-01

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

EFFECTS OF TIN ON HARDNESS, WEAR RATE AND COEFFICIENT OF FRICTION OF CAST CU-NI-SN ALLOYS

Directory of Open Access Journals (Sweden)

S. ILANGOVAN

2013-02-01

Full Text Available An investigation was carried out to understand the effects of Sn on hardness, wear rate and the coefficient of friction of spinodal Cu-Ni-Sn alloys. Alloys of appropriate compositions were melted in a crucible furnace under argon atmosphere and cast into sand moulds. Solution heat treated and aged specimens were tested for hardness, wear rate and the coefficient of friction. It was found that the hardness increases when the Sn content increases from 4% to 8% in the solution heat treated conditions. The peak aging time is found to decrease with an increase in the Sn content. Further, the coefficient of friction is independent of hardness whereas the wear rate decreases linearly with hardness irrespective of Sn content.

Progress of the Hard-wired Instrumentation and Control Works for the Neutral Beam Test Stand at KAERI

Energy Technology Data Exchange (ETDEWEB)

Jung, Ki Sok

2005-12-15

Progress of the hard-wired instrumentation and control works for the neutral beam test stand(NB-TS) has been existed for the past one year period. Details of the installed arc detector circuit are explained. LN{sub 2} level and temperature control during the cryosorption pumping operation are explained with an emphasis on its control circuit. With an expectation of more accurate and sensitive measurement of temperatures than the thermocouple utilization during the calorimeter operation, PT-100 resistance temperature detector(RTD) utilization is initiated and the results are described. During the ion beam experiment, physical measurements are made with some delayed time than the beam extraction, and thus a delayed trigger pulse generator was fabricated and installed to the system. Underlying principles of the electronic circuits for the interlock implementation and optical signal transmission are introduced. These are basically the application of operational amplifier circuits. A cautious aspect of the SMPS(switch mode power supply) utilization is also give.

Progress of the Hard-wired Instrumentation and Control Works for the Neutral Beam Test Stand at KAERI

International Nuclear Information System (INIS)

Jung, Ki Sok

2005-12-01

Progress of the hard-wired instrumentation and control works for the neutral beam test stand(NB-TS) has been existed for the past one year period. Details of the installed arc detector circuit are explained. LN 2 level and temperature control during the cryosorption pumping operation are explained with an emphasis on its control circuit. With an expectation of more accurate and sensitive measurement of temperatures than the thermocouple utilization during the calorimeter operation, PT-100 resistance temperature detector(RTD) utilization is initiated and the results are described. During the ion beam experiment, physical measurements are made with some delayed time than the beam extraction, and thus a delayed trigger pulse generator was fabricated and installed to the system. Underlying principles of the electronic circuits for the interlock implementation and optical signal transmission are introduced. These are basically the application of operational amplifier circuits. A cautious aspect of the SMPS(switch mode power supply) utilization is also give

Determination of the fatigue behaviour of thin hard coatings using the impact test and a FEM simulation

Energy Technology Data Exchange (ETDEWEB)

Bouzakis, K.D. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Vidakis, N. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Leyendecker, T. [CemeCon, 52068 Aachen (Germany); Lemmer, O. [CemeCon, 52068 Aachen (Germany); Fuss, H.G. [CemeCon, 52068 Aachen (Germany); Erkens, G. [CemeCon, 52068 Aachen (Germany)

1996-12-15

The impact test, in combination with a finite element method (FEM) simulation, is used to determine stress values that characterise the fatigue behaviour of thin hard coatings, such as TiAlN, TiAlCN, CrN, MoN, etc. The successive impacts of a cemented carbide ball onto a coated probe induce high contact loads, which can vary in amplitude and cause plastic deformation in the substrate. In the present paper FEM calculations are used in order to determine the critical stress values, which lead to coating fatigue failure. The parametric FEM simulation developed considers elastic behaviour for the coating and elastic plastic behaviour for the substrate. The results of the FEM calculations are correlated to experimental data, as well as to SEM observations of the imprints and to microspectrum analyses within the contact region. Herewith, critical values for various stress components, which are responsible for distinctive fatigue failure modes of the coating-substrate compounds can be obtained. (orig.)

Hard X-ray mirrors for Nuclear Security

Energy Technology Data Exchange (ETDEWEB)

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

2016-01-07

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

Impact velocity vs. target hardness relationships for equivalent response of cask structures

International Nuclear Information System (INIS)

Chen, T.F.; Chen, J.C.; Witte, M.C.; Fischer, L.E.

1993-01-01

In this paper, impact velocity vs. target hardness relationships for cask structures are reviewed. The relationships are based on equivalent cask responses in terms of equal deceleration or similar cask damages. By examining several past cask or container tests as well as some analytical results, some conclusions can be drawn about the relationship between target hardness and equivalent impact velocities. This relationship clearly shows that the cask response to impact is cask-dependent and that the rigid sphere impact model results in an unconservative estimate of equivalent velocity

Statistical Significance of the Maximum Hardness Principle Applied to Some Selected Chemical Reactions.

Science.gov (United States)

Saha, Ranajit; Pan, Sudip; Chattaraj, Pratim K

2016-11-05

The validity of the maximum hardness principle (MHP) is tested in the cases of 50 chemical reactions, most of which are organic in nature and exhibit anomeric effect. To explore the effect of the level of theory on the validity of MHP in an exothermic reaction, B3LYP/6-311++G(2df,3pd) and LC-BLYP/6-311++G(2df,3pd) (def2-QZVP for iodine and mercury) levels are employed. Different approximations like the geometric mean of hardness and combined hardness are considered in case there are multiple reactants and/or products. It is observed that, based on the geometric mean of hardness, while 82% of the studied reactions obey the MHP at the B3LYP level, 84% of the reactions follow this rule at the LC-BLYP level. Most of the reactions possess the hardest species on the product side. A 50% null hypothesis is rejected at a 1% level of significance.

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

Science.gov (United States)

Tumac, Deniz

2014-03-01

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

Aespoe Hard Rock Laboratory. Annual report 1997

International Nuclear Information System (INIS)

1998-05-01

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

Hard-hard coupling assisted anomalous magnetoresistance effect in amine-ended single-molecule magnetic junction

Science.gov (United States)

Tang, Y.-H.; Lin, C.-J.; Chiang, K.-R.

2017-06-01

We proposed a single-molecule magnetic junction (SMMJ), composed of a dissociated amine-ended benzene sandwiched between two Co tip-like nanowires. To better simulate the break junction technique for real SMMJs, the first-principles calculation associated with the hard-hard coupling between a amine-linker and Co tip-atom is carried out for SMMJs with mechanical strain and under an external bias. We predict an anomalous magnetoresistance (MR) effect, including strain-induced sign reversal and bias-induced enhancement of the MR value, which is in sharp contrast to the normal MR effect in conventional magnetic tunnel junctions. The underlying mechanism is the interplay between four spin-polarized currents in parallel and anti-parallel magnetic configurations, originated from the pronounced spin-up transmission feature in the parallel case and spiky transmission peaks in other three spin-polarized channels. These intriguing findings may open a new arena in which magnetotransport and hard-hard coupling are closely coupled in SMMJs and can be dually controlled either via mechanical strain or by an external bias.

Melting of polydisperse hard disks

NARCIS (Netherlands)

Pronk, S.; Frenkel, D.

2004-01-01

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

Growth and Saxitoxin Production by Cylindrospermopsis raciborskii (Cyanobacteria Correlate with Water Hardness

Directory of Open Access Journals (Sweden)

Sandra Maria Feliciano de Oliveira e Azevedo

2013-08-01

Full Text Available The cosmopolitan and increasing distribution of Cylindrospermopsis raciborskii can be attributed to its ecophysiological plasticity and tolerance to changing environmental factors in water bodies. In reservoirs in the semi-arid region of Brazil, the presence and common dominance of C. raciborskii have been described in waters that are considered hard. We investigated the response of a Brazilian C. raciborskii strain to water hardness by evaluating its growth and saxitoxin production. Based on environmental data, a concentration of 5 mM of different carbonate salts was tested. These conditions affected growth either positively (MgCO3 or negatively (CaCO3 and Na2CO3. As a control for the addition of cations, MgCl2, CaCl2 and NaCl were tested at 5 or 10 mM, and MgCl2 stimulated growth, NaCl slowed but sustained growth, and CaCl2 inhibited growth. Most of the tested treatments increased the saxitoxin (STX cell quota after six days of exposure. After 12 days, STX production returned to concentrations similar to that of the control, indicating an adaptation to the altered water conditions. In the short term, cell exposure to most of the tested conditions favored STX production over neoSTX production. These results support the noted plasticity of C. raciborskii and highlight its potential to thrive in hard waters. Additionally, the observed relationship between saxitoxin production and water ion concentrations characteristic of the natural environments can be important for understanding toxin content variation in other harmful algae that produce STX.

Implications of water hardness in ecotoxicological assessments for water quality regulatory purposes: a case study with the aquatic snail Biomphalaria glabrata (Say, 1818

Directory of Open Access Journals (Sweden)

EC Oliveira-Filho

Full Text Available Water hardness is a property depending on the presence of alkaline earth metals, mainly calcium and magnesium. Among the strategies for water quality monitoring, ecotoxicological assays are performed to minimize impacts and classify water bodies. For these laboratory evaluations parameters are previously defined in the guidelines, including water hardness for both cultivation and testing medium. The present work was performed to evaluate the effects of different levels of water hardness on the survival and reproduction of the freshwater snail Biomphalaria glabrata and discuss the influence of natural water hardness on the results of ecotoxicological tests with these environmental samples. Comparing the groups it was possible to observe that those maintained in waters with least hardness had lower reproductive success, while the groups maintained in highest hardness showed better reproduction. These data show that waters with low hardness make the reproduction of the snail B. glabrata unfeasible, and this reveal a problem for ecotoxicity assays using natural water samples.

Rock mechanics for hard rock nuclear waste repositories

International Nuclear Information System (INIS)

Heuze, F.E.

1981-09-01

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

Correlation between intrinsic hardness and defect structures of ion irradiated Fe alloys

International Nuclear Information System (INIS)

Shin, C.; Jin, H. H.; Kwon, J.

2008-01-01

Evolution of micro structures and mechanical properties during an in-service irradiation is one of the key issues to be addressed in nuclear materials. Ion irradiation is an effective method to study these irradiation effects thanks to an ease in handling post-irradiated specimens. But the characteristics of an ion irradiation pose a certain difficulty in evaluating irradiation effects. For example, ion irradiated region extends only a few hundred nano-meters from the surface of a sample and the depth profile of an irradiation damage level is quite heterogeneous. Thus it requires special care to quantify the changes in properties after an ion irradiation. We measured changes in a hardness by using a nano-indentation combined with a continuous stiffness measurement (CSM technique. Although the SM technique allows for a continuous measurement of hardness along penetration depth of an indenter; it is difficult to obtain an intrinsic hardness of an irradiation hardened region because one is measuring hardness of a hard layer located on a soft matrix. Thus we modeled the nano-indentation test by using a finite element method. We can extract the intrinsic hardness and the yield stress of an irradiation hardened region by using a so-called inverse method. We investigated the irradiation effects on Fe-Cr binary alloy by using the methods mentioned above. TEM analysis revealed that an irradiation forms dislocation loops with Burgers vector of and 1/2 . These loops varied in size and density with the Cr content and dose level. We discuss in detail a correlation between the measured irradiation-induced changes in the surface hardness and an irradiation induced defect. (authors)

Advances in hard nucleus cataract surgery

Directory of Open Access Journals (Sweden)

Wei Cui

2013-11-01

Full Text Available Security and perfect vision and fewer complications are our goals in cataract surgery, and hard-nucleus cataract surgery is always a difficulty one. Many new studies indicate that micro-incision phacoemulsification in treating hard nucleus cataract is obviously effective. This article reviews the evolution process of hard nuclear cataract surgery, the new progress in the research of artificial intraocular lens for microincision, and analyse advantages and disadvantages of various surgical methods.

Optical fiber composition and radiation hardness

International Nuclear Information System (INIS)

Wall, J.A.; Loretz, T.J.

1982-01-01

Germanium phosphosilicate and germanium borosilicate fibers doped with cerium were fabricated and tested for their responses to steady-state Co-60 radiation at -55 C, +20 C and +125 C. A fiber with germanium, boron and phosphorous in the silicate core and doped with antimony in the core and clad was similarly tested. All of the fibers showed significant improvements in radiation hardness at 20 C compared to undoped fibers of the same base composition. At -55 C, however, all except the cerium doped germanium phosphosilicate were very radiation sensitive and also showed increases in the rate of induced loss at +125 C. The cerium doped germanium phosphosilicate fiber showed virtually no change in radiation sensitivity at the temperature extremes and could prove useful in applications requiring relatively short lengths of fiber

Evaluation of workers exposed to dust containing hard metals and aluminum oxide.

Science.gov (United States)

Schwarz, Y; Kivity, S; Fischbein, A; Abraham, J L; Fireman, E; Moshe, S; Dannon, Y; Topilsky, M; Greif, J

1998-08-01

Fourteen worker exposed to hard metals and aluminum oxide were evaluated. Six heavily exposed workers underwent bronchoscopy and bronchoalveolar lavage, and five workers underwent transbronchial biopsy. Microchemical analysis of transbronchial biopsies showed a high lung burden of exogenous particles, especially metal related to their hard metals exposure. Lung tissue and cellular changes, which were associated with exposure to hard metal and aluminum oxide, corresponded well with the microanalytic test results. Three workers had at biopsy diffuse interstitial inflammatory changes: two of them were asymptomatic with normal chest X-ray films, and one had clinically evident disease with severe giant cell inflammation. Two other workers showed focal inflammation. The worker showing clinical disease and one asymptomatic worker with interstitial inflammatory changes had evaluated bronchoalveolar lavage fluid-eosinophilia counts. These two were father (with clinical disease) and son (asymptomatic).

The difference nanocomposite hardness level using LED photoactivation based on curing period variations

Directory of Open Access Journals (Sweden)

Hasiana Tatian

2011-03-01

Full Text Available Polimerizatian is the critical stage to determine the quality of composites resin, this involves isolated monomer carbon double bonds being converted to an extended network of single bonds. Physical and mechanical properties of composites are influenced by the level of conversion attained during polymerization. An adequate light intensity and light curing time are important to obtain the degree of polymerization. The objective of this study is to evaluate the difference of the hardness nanocomposites which activated by LED LCU based on the variation of curing times. This study is a true experimental research. The samples were made from nanocomposites material with cylinder form of 4 mm in depth, 6 mm in diameter. This samples divided into 3 groups of curing times. Group, I was cured for 20's curing time as a control due to manufactory recommended; Group II was cured for 30's, and Group III was cured for 40's and the hardness (Rebound hardness tester was determined using Rebound scale (RS and converted by Mohs scale (MS. There was a very significant level of hardness rate from each group using ANOVA test. The result of the study concludes that there were the differences on the nanocomposites hardness level cured under different curing times 20, 30 and 40 sec. The longer of curing times, the higher level of hardness.

Modelling of nuclear explosions in hard rock sites

International Nuclear Information System (INIS)

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

1993-01-01

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

A comparative tribological study of chromium coatings with different specific hardness

International Nuclear Information System (INIS)

Darbeida, A.; Von Stebut, J.; Barthole, M.; Belliard, P.; Lelait, L.

1995-06-01

The wear resistance in dry friction of two electrolytic and two pVD hard chromium coatings deposited on construction steel substrates is studied by means of standard pin on disc multi-pass, unidirectional operation. For both of these friction modes low cycle high load operation with cemented carbide pins leads to essentially coatings hardness controlled, abrasive wear. For these well adhering commercial coatings (both for through thickness cracking and for spalling failure) assessed by standard testing, are inadequate for quality ranking with respect to wear resistance. Steady state friction corresponds to a stabilised third body essentially composed of chromium oxide. (authors). 13 refs., 7 figs., 1 tab

Surface hardness evaluation of different composite resin materials: influence of sports and energy drinks immersion after a short-term period

Directory of Open Access Journals (Sweden)

Ugur Erdemir

2013-04-01

Full Text Available Objectives: This study evaluated the effect of sports and energy drinks on the surface hardness of different composite resin restorative materials over a 1-month period. Material and Methods: A total of 168 specimens: Compoglass F, Filtek Z250, Filtek Supreme, and Premise were prepared using a customized cylindrical metal mould and they were divided into six groups (N=42; n=7 per group. For the control groups, the specimens were stored in distilled water for 24 hours at 37°C and the water was renewed daily. For the experimental groups, the specimens were immersed in 5 mL of one of the following test solutions: Powerade, Gatorade, X-IR, Burn, and Red Bull, for two minutes daily for up to a 1-month test period and all the solutions were refreshed daily. Surface hardness was measured using a Vickers hardness measuring instrument at baseline, after 1-week and 1-month. Data were statistically analyzed using Multivariate repeated measure ANOVA and Bonferroni's multiple comparison tests (α=0.05. Results: Multivariate repeated measures ANOVA revealed that there were statistically significant differences in the hardness of the restorative materials in different immersion times (p<0.001 in different solutions (p<0.001. The effect of different solutions on the surface hardness values of the restorative materials was tested using Bonferroni's multiple comparison tests, and it was observed that specimens stored in distilled water demonstrated statistically significant lower mean surface hardness reductions when compared to the specimens immersed in sports and energy drinks after a 1-month evaluation period (p<0.001. The compomer was the most affected by an acidic environment, whereas the composite resin materials were the least affected materials. Conclusions: The effect of sports and energy drinks on the surface hardness of a restorative material depends on the duration of exposure time, and the composition of the material.

Zirconium nitride hard coatings

International Nuclear Information System (INIS)

Roman, Daiane; Amorim, Cintia Lugnani Gomes de; Soares, Gabriel Vieira; Figueroa, Carlos Alejandro; Baumvol, Israel Jacob Rabin; Basso, Rodrigo Leonardo de Oliveira

2010-01-01

Zirconium nitride (ZrN) nanometric films were deposited onto different substrates, in order to study the surface crystalline microstructure and also to investigate the electrochemical behavior to obtain a better composition that minimizes corrosion reactions. The coatings were produced by physical vapor deposition (PVD). The influence of the nitrogen partial pressure, deposition time and temperature over the surface properties was studied. Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and corrosion experiments were performed to characterize the ZrN hard coatings. The ZrN films properties and microstructure changes according to the deposition parameters. The corrosion resistance increases with temperature used in the films deposition. Corrosion tests show that ZrN coating deposited by PVD onto titanium substrate can improve the corrosion resistance. (author)

INFLUENCE OF THE THICKNESS OF Ni-P COATING APPLIED ON 7075 ALUMINUM ALLOY ON ITS HARDNESS

Directory of Open Access Journals (Sweden)

Kazimierz Czapczyk

2016-12-01

Full Text Available The paper presents the results of hardness tests of aluminum alloy AW-7075 (for plastic processing and Ni-P chemical coatings (nickel-phosphorus which had been applied by the no-current method. Coatings of various thickness have been made and their influence on the increase of the top layer hardness has been determined, as well as the increase of the hardness of the coating and substrate system after puncturing the coating with an indenter. The purpose of the investigation was to determine the possibility of applying the Ni-P coating for selected technical applications, among others, by the selection of its optimum thickness on the hard aluminum alloy and by the determination of the deformation resistance of the top layer if the given coating.

Hard probes in heavy ion collisions at the LHC: PDFs, shadowing and $pA$ collisions

CERN Document Server

Accardi, Alberto; Botje, M.; Brodsky, S.J.; Cole, B.; Eskola, K.J.; Fai, George I.; Frankfurt, L.; Fries, R.J.; Geist, Walter M.; Guzey, V.; Honkanen, H.; Kolhinen, V.J.; Kovchegov, Yu.V.; McDermott, M.; Morsch, A.; Qiu, Jian-wei; Salgado, C.A.; Strikman, M.; Takai, H.; Tapprogge, S.; Vogt, R.; Zhang, X.f.

2003-01-01

This manuscript is the outcome of the subgroup ``PDFs, shadowing and $pA$ collisions'' from the CERN workshop ``Hard Probes in Heavy Ion Collisions at the LHC''. In addition to the experimental parameters for $pA$ collisions at the LHC, the issues discussed are factorization in nuclear collisions, nuclear parton distributions (nPDFs), hard probes as the benchmark tests of factorization in $pA$ collisions at the LHC, and semi-hard probes as observables with potentially large nuclear effects. Also, novel QCD phenomena in $pA$ collisions at the LHC are considered. The importance of the $pA$ program at the LHC is emphasized.

The influence of material hardness on liquid droplet impingement erosion

International Nuclear Information System (INIS)

Fujisawa, Nobuyuki; Yamagata, Takayuki; Takano, Shotaro; Saito, Kengo; Morita, Ryo; Fujiwara, Kazutoshi; Inada, Fumio

2015-01-01

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

The influence of material hardness on liquid droplet impingement erosion

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-15

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

Initiative hard coal; Initiative Steinkohle

Energy Technology Data Exchange (ETDEWEB)

Leonhardt, J.

2007-08-02

In order to decrease the import dependence of hard coal in the European Union, the author has submitted suggestions to the director of conventional sources of energy (directorate general for energy and transport) of the European community, which found a positive resonance. These suggestions are summarized in an elaboration 'Initiative Hard Coal'. After clarifying the starting situation and defining the target the presupposition for a better use of hard coal deposits as raw material in the European Union are pointed out. On that basis concrete suggestions for measures are made. Apart from the conditions of the deposits it concerns thereby also new mining techniques and mining-economical developments, connected with tasks for the mining-machine industry. (orig.)

Hard diffraction and rapidity gaps

International Nuclear Information System (INIS)

Brandt, A.

1995-09-01

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

Effects of delayed finishing/polishing on surface roughness, hardness and gloss of tooth-coloured restorative materials.

Science.gov (United States)

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

2010-01-01

The aim of this study was to investigate the effect of delayed finishing/polishing on the surface roughness, hardness and gloss of tooth-coloured restorative materials. Four different tooth-coloured restoratives: a flowable resin composite- Tetric Flow, a hybrid resin composite- Venus, a nanohybrid resin composite- Grandio, and a polyacid modified resin composite- Dyract Extra were used. 30 specimens were made for each material and randomly assigned into three groups. The first group was finished/polished immediately and the second group was finished/polished after 24 hours. The remaining 10 specimens served as control. The surface roughness of each sample was recorded using a laser profilometer. Gloss measurements were performed using a small-area glossmeter. Vickers microhardness measurements were performed from three locations on each specimen surface under 100g load and 10s dwell time. Data for surface roughness and hardness were analyzed by Kruskal Wallis test and data for gloss were subjected to one-way ANOVA and Tukey test (P gloss values were recorded under Mylar strip for all materials. While delayed finishing/polishing resulted in a significantly higher gloss compared to immediate finishing/polishing in Venus samples (P .05). The lowest hardness values were found under Mylar strip. Delayed finishing/polishing significantly increased the hardness of all materials. The effect of delayed finishing/polishing on surface roughness, gloss and hardness appears to be material dependent.

Genetic analysis of kernel texture (grain hardness) in a hard red spring wheat (Triticum aestivum L.) bi-parental population

Science.gov (United States)

Grain hardness is a very important trait in determining wheat market class and also influences milling and baking traits. At the grain Hardness (Ha) locus on chromosome 5DS, there are two primary mutations responsible for conveying a harder kernel texture among U.S. hard red spring wheats: (1) the P...

Residual stress control and design of next-generation ultra-hard gear steels

Science.gov (United States)

Qian, Yana

In high power density transmission systems, Ni-Co secondary hardening steels have shown great potential for next-generation gear applications due to their excellent strength, toughness and superior fatigue performance. Study of residual stress generation and evolution in Ferrium C61 and C67 gear steels revealed that shot peening and laser peening processes effectively produce desired beneficial residual stress in the steels for enhanced fatigue performance. Surface residual stress levels of -1.4GPa and -1.5GPa were achieved in shot peened C61 and laser peened C67, respectively, without introducing large surface roughness or defects. Higher compressive residual stress is expected in C67 according to a demonstrated correlation between attainable residual stress and material hardness. Due to the lack of appropriate shot media, dual laser peening is proposed for future peening optimization in C67. A novel non-destructive synchrotron radiation technique was implemented and applied for the first time for residual stress distribution analysis in gear steels with large composition and property gradients. Observed substantial residual stress redistribution and material microstructure change during the rolling contact fatigue screening test with extremely high 5.4GPa load indicates the unsuitability of the test as a fatigue life predictor. To exploit benefits of higher case hardness and associated residual stress, a new material and process (CryoForm70) aiming at 70Rc surface hardness was designed utilizing the systems approach based on thermodynamics and secondary hardening mechanisms. The composition design was first validated by the excellent agreement between experimental and theoretical core martensite start temperature in the prototype. A novel cryogenic deformation process was concurrently designed to increase the case martensite volume fraction from 76% to 92% for enhanced strengthening efficiency and surface hardness. High temperature vacuum carburizing was

Numerical analysis of control of hard roof's stepped cantilever structure for longwall mining with sublevel caving

Energy Technology Data Exchange (ETDEWEB)

Wei, J.; Jin, Z.; Tang, Y. [Taiyuan University of Technology, Taiyuan (China)

2002-12-01

Based on the field monitoring and simulation test of strata movement, the hard roof's stepped cantilever structure and its mechanics model are presented. The finite element method is used to analyse the effect of hard coal cracking under the abutment pressure of hard roof, so the rational pre-treatment span of hard roof is determined, and the rational working resistance of support is selected also. According to the mechanics model, the transient balance conditions of the hard roof's stepped cantilever structure are studied, and the support-rock relation is theoretically explained. As a result, the basic theory and technique of surrounding rocks control for fully mechanised longwall mining with sub-level caving is formed under the hard roof and hard coal conditions, and the hard roof is effectively controlled not only to protect the working face but also to promote the caving of hard top-coal to increase the recovery rate of coal, thus to realise safe and highly efficient and productive fully mechanised longwall mining with sub-level caving in extra-thick seam. Finally, the successfully practice of hard roof control in 8914 and 8911 working face is presented in this paper. 10 refs., 5 figs., 4 tabs.

Study of hard processes in the ALICE experiment

CERN Document Server

Vajzer, Michal; Bielcikova, Jana

2015-01-01

Jets are collimated sprays of particles resulting from fragmentation of associated hard scattered partons. They are measured in different types of collisions at different energies to test perturbative quantum chromodynamic calculations and are used to study the hard scattering, fragmentation, hadronisation and other properties of partons. These properties studied in simple systems such as proton-proton collisions, serve as a baseline to investigate their modifications by hot and dense nuclear matter created in high energy heavy-ion collisions. This thesis presents analysis of data from minimum bias proton-proton collisions at centre of mass energy of 2.76 and 7 TeV collected using the ALICE detector system at the LHC is presented with jet transverse momenta in range from 20 GeV/c to 100 GeV/c. Reconstruction of the inclusive jet cross-section from charged tracks at midrapidity is done using standard modern anti-k$_T$ and k$_T$ algorithms with underlying event subtraction and correction for detector effects vi...

The rad-hard readout system of the BaBar silicon vertex tracker

Science.gov (United States)

Re, V.; DeWitt, J.; Dow, S.; Frey, A.; Johnson, R. P.; Kroeger, W.; Kipnis, I.; Leona, A.; Luo, L.; Mandelli, E.; Manfredi, P. F.; Nyman, M.; Pedrali-Noy, M.; Poplevin, P.; Perazzo, A.; Roe, N.; Spencer, N.

1998-02-01

This paper discusses the behaviour of a prototype rad-hard version of the chip developed for the readout of the BaBar silicon vertex tracker. A previous version of the chip, implemented in the 0.8 μm HP rad-soft version has been thoroughly tested in the recent times. It featured outstanding noise characteristics and showed that the specifications assumed as target for the tracker readout were met to a very good extent. The next step was the realization of a chip prototype in the rad-hard process that will be employed in the actual chip production. Such a prototype is structurally and functionally identical to its rad-soft predecessor. However, the process parameters being different, and not fully mastered at the time of design, some deviations in the behaviour were to be expected. The reasons for such deviations have been identified and some of them were removed by acting on the points that were left accessible on the chip. Other required small circuit modifications that will not affect the production schedule. The tests done so far on the rad-hard chip have shown that the noise behaviour is very close to that of the rad-soft version, that is fully adequate for the vertex detector readout.

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

Science.gov (United States)

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

2010-05-01

The durometer is a hardness tester developed to measure hardness of metallic materials that has been recently introduced to measure rock hardness in weathering studies. Aoki & Matsukura (2007) highlight some advantages of the durometer compared with the Schmidt Rock Test Hammer: the smaller plunge allows measurements in small surfaces such as taffoni or rock carvings, the wider measurement range and the lower impact energy. This last makes it a non destructive method that can be used on relatively soft rocks. In this work the durometer Equotip (©) has been tested in different environments in the field and in the laboratory to explore its applicability and limitations. We applied the device on small rock samples of granite and limestone and a T-test showed that smaller sample size gave smaller hardness values (p values obtained inside and outside the grooves of the carvings using two different support rings, one flat and one concave. The flat ring was not able to reach the bottom of the groove, meanwhile the concave ring adjusts fairly well given its semi spherical section. A t-test confirmed the difference (p values obtained in the grooves using the flat ring and the higher and less scattered values obtained when the concave ring is used. As a very sensitive device, there are some problems in the use related with rock roughness and rock grain size. In weathered medium to coarse grained rocks, with very irregular surfaces, is not easy to get a good contact between the plunge and the rock surface. A poor contact caused by surface roughness causes the scattering and lowering of rebound values. On the contrary, in homogeneous fine grained rocks and in uniform rock surfaces the device gave very good results. The data obtained in glacial, nival and rock coastal environments showed the potential of the device in the identification of changes in rock hardness. We were able to asses the changes in the weathering degree of glacial striations and marked differences in the

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

Science.gov (United States)

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.

Isotropic-nematic transition in a mixture of hard spheres and hard spherocylinders: scaled particle theory description

Directory of Open Access Journals (Sweden)

M.F. Holovko

2017-12-01

Full Text Available The scaled particle theory is developed for the description of thermodynamical properties of a mixture of hard spheres and hard spherocylinders. Analytical expressions for free energy, pressure and chemical potentials are derived. From the minimization of free energy, a nonlinear integral equation for the orientational singlet distribution function is formulated. An isotropic-nematic phase transition in this mixture is investigated from the bifurcation analysis of this equation. It is shown that with an increase of concentration of hard spheres, the total packing fraction of a mixture on phase boundaries slightly increases. The obtained results are compared with computer simulations data.

Effects of ion implantation on the hardness and friction behaviour of soda-lime silica glass

International Nuclear Information System (INIS)

Bull, S.J.; Page, T.F.

1992-01-01

Ion implantation-induced changes in the near-surface mechanical properties of soda-lime silica glass have been investigated by indentation and scratch testing and have been found to be more complicated than changes in the corresponding properties of crystalline ceramic materials. Argon, nitrogen, carbon and potassium ions were used with energies in the range 45-300 keV. Hardness and scratch friction tests were performed under ambient laboratory conditions. At low doses, a decrease in hardness and an increase in both friction and surface stress are observed which are attributed to the electronic damage produced by ion implantation. At higher doses, the hardness increases again and a maximum is produced similar to the behaviour observed for crystalline materials. Similarly there is found to be a second stress and friction peak at this dose. This behaviour is shown to be due to the build-up of displacement damage produced by ion implantation and is thus very similar to the radiation hardening (and eventual amorphization) behaviour of ion-implanted crystalline ceramics. For glass, ''amorphization'' probably corresponds to some change in the existing amorphous state which, in turn, is responsible for the reduction in hardness, stress and friction at the highest doses. (author)

Effect of storage in water and thermocycling on hardness and roughness of resin materials for temporary restorations

Directory of Open Access Journals (Sweden)

Jerusa Cleci de Oliveira

2010-09-01

Full Text Available PURPOSE: This study evaluated the effect of storage in water and thermocycling on hardness and roughness of resin materials for temporary restorations. MATERIAL AND METHODS: Three acrylic resins (Dencor-De, Duralay-Du, and Vipi Cor-VC were selected and one composite resin (Opallis-Op was used as a parameter for comparison. The materials were prepared according to the manufacturers' instructions and were placed in stainless steel moulds (20 mm in diameter and 5 mm thick. Thirty samples of each resin were made and divided into three groups (n = 10 according to the moment of Vickers hardness (VHN and roughness (Ra analyses: C (control group: immediately after specimen preparation; Sw: after storage in distilled water at 37 °C for 24 hours; Tc: after thermocycling (3000 cycles; 5-55 °C, 30 seconds dwell time. Data were submitted to 2-way ANOVA followed by Tukey's test (α = 0.05. RESULTS: Op resin had higher surface hardness values (p 0.05 in roughness among materials (De = 0.31 ± 0.07; Du = 0.51 ± 0.20; VC = 0.41 ± 0.15; Op = 0.42 ± 0.18. Storage in water did not change hardness and roughness of the tested materials (p > 0.05. There was a significant increase in roughness after thermocycling (p < 0.05, except for material Du, which showed no significant change in roughness in any evaluated period (p = 0.99. CONCLUSION: Thermocycling increased the roughness in most tested materials without affecting hardness, while storage in water had no significant effect in the evaluated properties.

Effect of Repeated Microwave Disinfection on Surface Hardness and Dimensional Accuracy of Two Dental Stone Materials

Directory of Open Access Journals (Sweden)

Mahmood Robati Anaraki

2015-01-01

Full Text Available There is controversial evidence in relation to the effect of microwave on mechanical properties of stone casts. The present study was designed to evaluate the effect of repeated microwave disinfection on surface hardness and dimensional accuracy of dental stone. In this in vitro study, 48 cylindrical stone samples were prepared using two products of type IV stone to assess surface hardness and 48 impressions were taken from a model and poured by these stones to assess the dimensional accuracy. The evaluation of the samples was carried out consequently by a micro-hardness tester and a digital caliper after the stone samples were exposed to 7 consecutive rounds of 900 watts (W microwave irradiation for five minutes each time after cooling. Data were analyzed by t-test and ANOVA. According to the obtained results, multiple disinfections of the stone casts by microwave do not negatively affect their surface hardness and dimensional accuracy.   Key words: Dental stone; Dimensional accuracy; Hardness; Microwave

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

Science.gov (United States)

Reed, James L

2008-07-07

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

Aespoe Hard Rock Laboratory. Annual report 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

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

Hard Copy Market Overview

Science.gov (United States)

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

No evidence of African swine fever virus replication in hard ticks

NARCIS (Netherlands)

Carvalho Ferreira, de H.C.; Zúquete, S.T.; Wijnveld, M.; Weesendorp, E.; Jongejan, F.; Stegeman, J.A.; Loeffen, W.L.A.

2014-01-01

African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in

No evidence of African swine fever virus replication in hard ticks

NARCIS (Netherlands)

de Carvalho Ferreira, Helena C; Tudela Zúquete, Sara; Wijnveld, Michiel; Weesendorp, Eefke; Jongejan, Frans; Stegeman, Arjan; Loeffen, Willie L A

African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in

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

Directory of Open Access Journals (Sweden)

Nakanishi Koichi

2012-06-01

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

Dose dependence of nano-hardness of 6H-SiC crystal under irradiation with inert gas ions

Science.gov (United States)

Yang, Yitao; Zhang, Chonghong; Su, Changhao; Ding, Zhaonan; Song, Yin

2018-05-01

Single crystal 6H-SiC was irradiated by inert gas ions (He, Ne, Kr and Xe ions) to various damage levels at room temperature. Nano-indentation test was performed to investigate the hardness change behavior with damage. The depth profile of nano-hardness for 6H-SiC decreased with increasing depth for both the pristine and irradiated samples, which was known as indentation size effect (ISE). Nix-Gao model was proposed to determine an asymptotic value of nano-hardness by taking account of ISE for both the pristine and irradiated samples. In this study, nano-hardness of the irradiated samples showed a strong dependence on damage level and showed a weak dependence on ions species. From the dependence of hardness on damage, it was found that the change of hardness demonstrated three distinguishable stages with damage: (I) The hardness increased with damage from 0 to 0.2 dpa and achieved a maximum of hardening fraction ∼20% at 0.2 dpa. The increase of hardness in this damage range was contributed to defects produced by ion irradiation, which can be described well by Taylor relation. (II) The hardness reduced rapidly with large decrement in the damage range from 0.2 to 0.5 dpa, which was considered to be from the covalent bond breaking. (III) The hardness reduced with small decrement in the damage range from 0.5 to 2.2 dpa, which was induced by extension of the amorphous layer around damage peak.

GRE math tests

CERN Document Server

Kolby, Jeff

2014-01-01

Twenty-three GRE Math Tests! The GRE math section is not easy. There is no quick fix that will allow you to ""beat"" the section. But GRE math is very learnable. If you study hard and master the techniques in this book, your math score will improve--significantly! The GRE cannot be ""beaten."" But it can be mastered--through hard work, analytical thought, and by training yourself to think like a test writer. Many of the problems in this book are designed to prompt you to think like a test writer. For example, you will find ""Duals."" These are pairs of similar problems in which only one prop

Hard and soft acids and bases: structure and process.

Science.gov (United States)

Reed, James L

2012-07-05

Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.

Correlating particle hardness with powder compaction performance.

Science.gov (United States)

Cao, Xiaoping; Morganti, Mikayla; Hancock, Bruno C; Masterson, Victoria M

2010-10-01

Assessing particle mechanical properties of pharmaceutical materials quickly and with little material can be very important to early stages of pharmaceutical research. In this study, a wide range of pharmaceutical materials were studied using atomic force microscopy (AFM) nanoindentation. A significant amount of particle hardness and elastic modulus data were provided. Moreover, powder compact mechanical properties of these materials were investigated in order to build correlation between the particle hardness and powder compaction performance. It was found that the materials with very low or high particle hardness most likely exhibit poor compaction performance while the materials with medium particle hardness usually have good compaction behavior. Additionally, the results from this study enriched Hiestand's special case concept on particle hardness and powder compaction performance. This study suggests that the use of AFM nanoindentation can help to screen mechanical properties of pharmaceutical materials at early development stages of pharmaceutical research.

Hardness optimization of boride diffusion layer on Astm F-75 alloy using response surface methodology

Energy Technology Data Exchange (ETDEWEB)

Arguelles O, J. L.; Corona R, M. A. [Universidad Autonoma de San Luis Potosi, Doctorado Institucional en Ingenieria y Ciencia de Materiales, San Luis Potosi 78000, SLP (Mexico); Marquez H, A.; Saldana R, A. L.; Saldana R, A. [Universidad de Guanajuato, Ingenieria Mecanica Agricola DICIVA, Irapuato, Guanajuato 36500 (Mexico); Moreno P, J., E-mail: amarquez@ugto.mx [Universidad de Guanajuato, Departamento de Minas, Metalurgia y Geologia, Ex-Hacienda San Matias s/n, Guanajuato, Guanajuato 36020 (Mexico)

2017-11-01

In this study, the Response Surface Methodology (Rsm) and Central Composite Design (Ccd) were used to optimize the hardness of boride diffusion layer on Astm F-75 alloy (also called Haynes alloy). A boronizing thermochemical treatment was carried out at different temperatures and for different time periods. Hardness tests were conducted. The boride diffusion layer was verified by the X-ray diffraction (XRD) analysis indicating the formation of Co B, Co{sub 2}B, Cr B and Mo{sub 2}B phases. An optimal hardness of 3139.7 Hv was obtained for the samples subjected to the boriding process for a duration of 6.86 h at 802.4 degrees Celsius. (Author)

Comparative Assessment of Cutting Inserts and Optimization during Hard Turning: Taguchi-Based Grey Relational Analysis

Science.gov (United States)

Venkata Subbaiah, K.; Raju, Ch.; Suresh, Ch.

2017-08-01

The present study aims to compare the conventional cutting inserts with wiper cutting inserts during the hard turning of AISI 4340 steel at different workpiece hardness. Type of insert, hardness, cutting speed, feed, and depth of cut are taken as process parameters. Taguchi’s L18 orthogonal array was used to conduct the experimental tests. Parametric analysis carried in order to know the influence of each process parameter on the three important Surface Roughness Characteristics (Ra, Rz, and Rt) and Material Removal Rate. Taguchi based Grey Relational Analysis (GRA) used to optimize the process parameters for individual response and multi-response outputs. Additionally, the analysis of variance (ANOVA) is also applied to identify the most significant factor.

Failure mechanism and coupled static-dynamic loading theory in deep hard rock mining: A review

Directory of Open Access Journals (Sweden)

Xibing Li

2017-08-01

Full Text Available Rock failure phenomena, such as rockburst, slabbing (or spalling and zonal disintegration, related to deep underground excavation of hard rocks are frequently reported and pose a great threat to deep mining. Currently, the explanation for these failure phenomena using existing dynamic or static rock mechanics theory is not straightforward. In this study, new theory and testing method for deep underground rock mass under coupled static-dynamic loading are introduced. Two types of coupled loading modes, i.e. “critical static stress + slight disturbance” and “elastic static stress + impact disturbance”, are proposed, and associated test devices are developed. Rockburst phenomena of hard rocks under coupled static-dynamic loading are successfully reproduced in the laboratory, and the rockburst mechanism and related criteria are demonstrated. The results of true triaxial unloading compression tests on granite and red sandstone indicate that the unloading can induce slabbing when the confining pressure exceeds a certain threshold, and the slabbing failure strength is lower than the shear failure strength according to the conventional Mohr-Column criterion. Numerical results indicate that the rock unloading failure response under different in situ stresses and unloading rates can be characterized by an equivalent strain energy density. In addition, we present a new microseismic source location method without premeasuring the sound wave velocity in rock mass, which can efficiently and accurately locate the rock failure in hard rock mines. Also, a new idea for deep hard rock mining using a non-explosive continuous mining method is briefly introduced.

Computational Modeling Develops Ultra-Hard Steel

Science.gov (United States)

2007-01-01

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

Problems in education, employment and social integration of hard of hearing artists

Directory of Open Access Journals (Sweden)

Radić-Šestić Marina

2013-01-01

Full Text Available The aim of this research was to determine the problems in education (primary, secondary and undergraduate academic studies, employment and social integration of hard of hearing artists based on a multiple case study. The sample consisted of 4 examinees of both genders, aged between 29 and 54, from the field of visual arts (a painter, a sculptor, a graphic designer, and an interior designer. The structured interview consisted of 30 questions testing three areas: the first area involved family, primary and secondary education; the second area was about the length of studying and socio-emotional problems of the examinees; the third area dealt with problems in employment and job satisfaction of our examinees. Research results indicate the existence of several problems which more or less reflect the success in education, employment and social integration of hard of hearing artists. One of the problems which can influence the development of language abilities, socioemotional maturity, and better educational achievement of hard of hearing artists in general, is prolongation in diagnosing hearing impairments, amplification and auditory rehabilitation. Furthermore, parents of hard of hearing artists have difficulties in adjusting to their children's hearing impairments and ignore the language and culture of the Deaf, i.e. they tend to identify their children with typically developing population. Another problem are negative attitudes of teachers/professors/employers and typically developing peers/ colleagues towards the inclusion of hard of hearing people into the regular education/employment system. Apart from that, unmodified instruction, course books, information, school and working area further complicate the acquisition of knowledge, information, and the progress of hard of hearing people in education and profession.

Cognitive behaviour modification: a technique for teaching subtraction skills to hearing and deaf/hard-of-hearing elementary students.

Science.gov (United States)

Al-Hilawani, Y A

2000-09-01

The purpose of this study was to examine the influence of using the Cognitive Behaviour Modification (CBM) technique on the subtraction skills of third grade hearing and deaf/hard-of-hearing students. The results indicated that the CBM deaf/hard-of-hearing students and the CBM and non-CBM hearing students made more progress in solving the subtraction problems than the non-CBM deaf/hard-of-hearing students. The results also showed that there were no significant differences between the CBM deaf/hard-of-hearing and the non-CBM hearing students; and there were no significant differences between the CBM and non-CBM hearing students. The results revealed that the CBM hearing students achieved significantly higher post-test scores than the CBM deaf/hard-of-hearing students. However, the CBM deaf/hard-of-hearing students obtained a significantly higher gain score compared to the CBM and non-CBM hearing students. Implications for teachers and suggestions for future research are discussed in this paper.

Methane in German hard coal mining

International Nuclear Information System (INIS)

Martens, P.N.; Den Drijver, J.

1995-01-01

Worldwide, hard coal mining is being carried out at ever increasing depth, and has, therefore, to cope with correspondingly increasing methane emissions are caused by coal mining. Beside carbon dioxide, chloro-fluoro-carbons (CFCs) and nitrogen oxides, methane is one of the most significant 'greenhouse' gases. It is mainly through the release of such trace gases that the greenhouse effect is brought about. Reducing methane emissions is therefore an important problem to be solved by the coal mining industry. This paper begins by highlighting some of the fundamental principles of methane in hard coal mining. The methane problem in German hard coal mining and the industry's efforts to reduce methane emissions are presented. The future development in German hard coal mining is illustrated by an example which shows how large methane volumes can be managed, while still maintaining high outputs at increasing depth. (author). 7 tabs., 10 figs., 20 refs

Double hard scattering without double counting

Energy Technology Data Exchange (ETDEWEB)

Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gaunt, Jonathan R. [VU Univ. Amsterdam (Netherlands). NIKHEF Theory Group; Schoenwald, Kay [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2017-02-15

Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

Double hard scattering without double counting

International Nuclear Information System (INIS)

Diehl, Markus; Gaunt, Jonathan R.

2017-02-01

Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

Nanomechanics of hard films on compliant substrates.

Energy Technology Data Exchange (ETDEWEB)

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

2009-09-01

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

The High Aspect Ratio Design (HARD): A candidate ITER concept with improved technology phase performance

International Nuclear Information System (INIS)

Nevins, W.M.; Perkins, L.J.; Wesley, J.C.

1992-10-01

The High Aspect Ratio Design (HARD) International Thermonuclear Experimental Reactor (ITER) concept developed by the US ITER team is an alternate to the low-aspect-ratio ITER design developed by the ITER participants during the Conceptual Design Activity (CDA). The CDA design, referred to hereafter as ITER CDA, has an aspect ratio, A, of 2.79, a toroidal magnetic field, B T , of 4.85 T, and a plasma current, I p , of 22 MA for operation with an ignited plasma. In contrast, HARD employs higher aspect ratio, A = 4.0, higher toroidal field, B T = 7.11 T, and lower plasma current, I p = 14.8 MA for ignition operation. The cross sections of the two designs are compared in. The parameters and performance of HARD and ITER CDA for inductively driven ignition operation are compared in. The HARD parameters provide the same ignition performance (ignition margin evaluated against ITER-89P confinement scaling) as ITER CDA in a device with comparable size and cost. However, the reason for advancing HARD rather than ITER CDA as the ITER design concept is not inductively driven ignition performance but HARD's significantly enhanced potential to achieve the technology testing and steady-state operation goals of the ITER objectives with non-inductive current drive

Dependence of hardness and impact energy on cooling time Δt8/5and temperature for S960QL

OpenAIRE

Samardžić, I.; Dunđer, M.; Vuherer, T.

2015-01-01

The paper deals with research into dependence of hardness and impact energy of thermal cycle simulated specimens of fine-grained structural steel S960QL on cooling time from 800 to 500 °C and on tested temperature. Results were obtained by measuring hardness of HV 10 and by experimental testing of Charpy notched tubes on instrumented Charpy hammer. Total impact energy, initiation energy and fracture propagation energy needed for occurrence of fracture is also elaborated. Key words:

NuSTAR Hard X-ray Optics

DEFF Research Database (Denmark)

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

2005-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a small explorer (SMEX) mission currently under an extended Phase A study by NASA. NuSTAR will be the first satellite mission to employ focusing optics in the hard X-ray band (8- 80 keV). Its design eliminates high detector backgrounds, allows...... and production process. We also describe the progress of several components of our independent optics development program that are beginning to reach maturity and could possibly be incorporated into the NuSTAR production scheme. We then present environmental test results that are being conducted in preparation...... of full space qualification of the NuSTAR optics....

Hard coatings by plasma CVD on polycarbonate for automotive and optical applications

International Nuclear Information System (INIS)

Schmauder, T.; Nauenburg, K.-D.; Kruse, K.; Ickes, G.

2006-01-01

In many applications, plastic surfaces need coatings as a protection against abrasion or weathering. Leybold Optics is developing Plasma CVD processes and machinery for transparent hard coatings (THC) for polycarbonate parts. In this paper we present the current features and remaining challenges of this technique. The coatings generally show excellent adhesion. Abrasion resistance is superior to commonly used lacquers. Climate durability of the coating has been improved to pass the tests demanded by automotive specifications. Current activities are focused on improving the durability under exposure to UV radiation. Estimations show that our high-rate plasma CVD hard coating process is also economically competitive to lacquering

Nanostructural Evolution of Hard Turning Layers in Carburized Steel

Science.gov (United States)

Bedekar, Vikram

speed indicated thermal transformation. Nanoindentation tests showed that the substructures produced by plastic deformation follow the Hall-Petch relationship while the structures produced by thermal transformation did not. This indicated a change in the hardness driver from dislocation hardening to phase transformation, both of which have a significant impact on fatigue life. Using hardness based flow stress numerical model, these relationships between the processing conditions and structural parameters were further explored. Results indicated that the hard turning process design space can be partitioned into three regions based on thermal phase transformations, plastic grain refinement, and a third regime where both mechanisms are active. It was found that the Zener-Holloman parameter can not only be used to predict post-turning grain size but also to partition the process space into regions of dominant microstructural mechanisms.

Analysis of Hard Thin Film Coating

Science.gov (United States)

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.

Rapid changes in water hardness and alkalinity: Calcite formation is lethal to Daphnia magna.

Science.gov (United States)

Bogart, Sarah J; Woodman, Samuel; Steinkey, Dylan; Meays, Cindy; Pyle, Greg G

2016-07-15

There is growing concern that freshwater ecosystems may be negatively affected by ever-increasing anthropogenic inputs of extremely hard, highly alkaline effluent containing large quantities of Ca(2+), Mg(2+), CO3(2-), and HCO3(-) ions. In this study, the toxicity of rapid and extreme shifts in water hardness (38-600mg/L as CaCO3) and alkalinity (30-420mg/L as CaCO3) to Daphnia magna was tested, both independently and in combination. Within these ranges, where no precipitation event occurred, shifts in water hardness and/or alkalinity were not toxic to D. magna. In contrast, 98-100% of D. magna died within 96h after exposure to 600mg/L as CaCO3 water hardness and 420mg/L as CaCO3 alkalinity (LT50 of 60h with a 95% CI of 54.2-66.0h). In this treatment, a CaCO3 (calcite) precipitate formed in the water column which was ingested by and thoroughly coated the D. magna. Calcite collected from a mining impacted stream contained embedded organisms, suggesting field streams may also experience similar conditions and possibly increased mortality as observed in the lab tests. Although further investigation is required to determine the exact fate of aquatic organisms exposed to rapid calcite precipitation in the field, we caution that negative effects may occur more quickly or at lower concentrations of water hardness and alkalinity in which we observed effects in D. magna, because some species, such as aquatic insects, are more sensitive than cladocerans to changes in ionic strength. Our results provide evidence that both calcite precipitation and the major ion balance of waters should be managed in industrially affected ecosystems and we support the development of a hardness+alkalinity guideline for the protection of aquatic life. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Subgroup report on hard x-ray microprobes

International Nuclear Information System (INIS)

Ice, G.E.; Barbee, T.; Bionta, R.; Howells, M.; Thompson, A.C.; Yun, W.

1994-01-01

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

Vickers Hardness of Diamond and cBN Single Crystals: AFM Approach

Directory of Open Access Journals (Sweden)

Sergey Dub

2017-12-01

Full Text Available Atomic force microscopy in different operation modes (topography, derivative topography, and phase contrast was used to obtain 3D images of Vickers indents on the surface of diamond and cBN single crystals with high spatial resolution. Confocal Raman spectroscopy and Kelvin probe force microscopy were used to study the structure of the material in the indents. It was found that Vickers indents in diamond has no sharp and clear borders. However, the phase contrast operation mode of the AFM reveals a new viscoelastic phase in the indent in diamond. Raman spectroscopy and Kelvin probe force microscopy revealed that the new phase in the indent is disordered graphite, which was formed due to the pressure-induced phase transformation in the diamond during the hardness test. The projected contact area of the graphite layer in the indent allows us to measure the Vickers hardness of type-Ib synthetic diamond. In contrast to diamond, very high plasticity was observed for 0.5 N load indents on the (001 cBN single crystal face. Radial and ring cracks were absent, the shape of the indents was close to a square, and there were linear details in the indent, which looked like slip lines. The Vickers hardness of the (111 synthetic diamond and (111 and (001 cBN single crystals were determined using the AFM images and with account for the elastic deformation of the diamond Vickers indenter during the tests.

Analysis of the development and performance of hard disks

OpenAIRE

Novak, Davorin

2010-01-01

With the emergence of new technologies in the field of hard drives we can witness a significant increase of surface density and transfer rate of interfaces which, as a result, enables greater performance and reliability of hard disks. The reason for this are increasing needs for higher capacities and data transfer rate to or from the hard disk. This thesis presents the structure of hard drives, features, performance and reliability of hard drives and alternative data storage technologies. Par...

Hardness of model dental composites - the effect of filler volume fraction and silanation.

Science.gov (United States)

McCabe, J F; Wassell, R W

1999-05-01

The relationship between structure and mechanical properties for dental composites has often proved difficult to determine due to the use of commercially available materials having a number of differences in composition i.e. different type of resin, different type of filler, etc. This makes a scientific study of any one variable such as filler content difficult if not impossible. In the current study it was the aim to test the hypothesis that hardness measurements of dental composites could be used to monitor the status of the resin-filler interface and to determine the efficacy of any particle silanation process. Ten model composites formulated from a single batch of resin and containing a common type of glass filler were formulated to contain varying amounts of filler. Some materials contained silanated filler, others contained unsilanated filler. Specimens were prepared and stored in water and hardness (Vickers') was determined at 24 h using loads of 50, 100, 200 and 300 g. Composites containing silanated fillers were significantly harder than materials containing unsilanated fillers. For unsilanated products hardness was independent of applied load and in this respect they behaved like homogeneous materials. For composites containing silanated fillers there was a marked increase in measured hardness as applied load was increased. This suggests that the hardness-load profile could be used to monitor the status of the resin-filler interface. Copyright 1999 Kluwer Academic Publishers

State-of-the-Art Report for the Deep URL Facility Development : Aspo Hard Rock Laboratory, Grimsel Test Site

International Nuclear Information System (INIS)

Kim, Kyung Su; Bae, Dae Seok; Kim, Geon Young

2012-01-01

This report analysed the development status on the SKB's Hard Rock Laboratory and Nagra's Grimsel Test Site facilities to investigate their facility overview, operation system, site condition, project history and procedure, and current experiment programmes of underground research laboratory. SKB and Nagra had launched high level radioactive waste disposal project around 1970's. Actual site investigation activities were initiated since 1990's and the time schedule for siting programmes to determine the final disposal site were taken fifteen to thirty years. Furthermore, ten to twenty years will be needed to site characterization, facility design, construction, and operation commissioning. Nagra had constructed Grimsel Test Site facility in southern Switzerland Apls with the collaboration of KWO electrical company in early 1980's. This facility is characterized of a centre of excellence for underground Research and Development (R and D) to support projects for the disposal of radioactive and chemo-toxic waste and not a potential repository site. The SKB's Aspo HRL constructed in outside Oskarshamn is a unique PBG-URL facility. SKB is conducting full-scale research and development here in preparation for the construction of a final repository for spent nuclear fuel. The research programmes for the development of disposal technologies is performed over thirty to fifty years prior to repository operation. In 2000's, research on long-term phenomena, i.e., optimization of disposal concept, understanding of coupling process, validation of mathematical model, test and development of safety assessment models, characterization of deep geochemical environment, and long-term demonstration experiments have been leading the issues of research and development

State of the art in hard-on-hard bearings: how did we get here and what have we achieved?

Science.gov (United States)

Zywiel, Michael G; Sayeed, Siraj A; Johnson, Aaron J; Schmalzried, Thomas P; Mont, Michael A

2011-03-01

Total hip arthroplasty has shown excellent results in decreasing pain and improving function in patients with degenerative disease of the hip. Improvements in prosthetic materials, designs and implant fixation have now resulted in wear of the bearing surface being the limitation of this technology, and a number of hard-on-hard couples have been introduced to address this concern. The purpose of this article is to review the origins, development, survival rates and potential advantages and disadvantages of the following hard-on-hard bearings for total hip arthroplasty: metal-on-metal standard total hip arthroplasty; metal-on-metal hip resurfacing arthroplasty, ceramic-on-ceramic total hip arthroplasty; and ceramic-on-metal bearings. Improvements in the manufacturing of metal-on-metal bearings over the past 50 years have resulted in implants that provide low wear rates and allow for the use of large femoral heads. However, concerns remain regarding elevated serum metal ion levels, potential teratogenic effects and potentially devastating adverse local tissue reactions, whose incidence and pathogenesis remains unclear. Modern total hip resurfacing has shown excellent outcomes over 10 years in the hands of experienced surgeons. Current ceramic-on-ceramic bearings have demonstrated excellent survival with exceptionally low wear rates and virtually no local adverse effects. Concerns remain for insertional chipping, in vivo fracture and the variable incidence of squeaking. Contemporary ceramic-on-metal interfaces are in the early stages of clinical use, with little data reported to date. Hard-on-hard bearings for total hip arthroplasty have improved dramatically over the past 50 years. As bearing designs continue to improve with new and modified materials and improved manufacturing techniques, it is likely that the use of hard-on-hard bearings will continue to increase, especially in young and active patients.

LARGE AREA FILTERED ARC DEPOSITION OF CARBON AND BORON BASED HARD COATINGS

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Rabi S.

2003-12-05

This document is a final report covering work performed under Contract No. DE-FG02-99ER82911 from the Department of Energy under a SBIR Phase II Program. Wear resistant, hard coatings can play a vital role in many engineering applications. The primary goal of this project was to develop coatings containing boron and carbon with hardness greater than 30 GPa and evaluate these coatings for machining applications. UES has developed a number of carbon and boron containing coatings with hardness in the range of 34 to 65 GPa using a combination of filtered cathodic arc and magnetron sputtering. The boron containing coatings were based on TiB2, TiBN, and TiBCN, while the carbon containing coatings ere TiC+C and hydrogen free diamond-like-carbon. Machining tests were performed with single and multilayer coated tools. The turning and milling tests were run at TechSolve Inc., under a subcontract at Ohio State University. Significant increases in tool lives were realized in end milling of H-13 die steel (8X) and titanium alloy (80%) using the TiBN coating. A multilayer TiBN/TiN performed the best in end-milling of highly abrasive Al-Si alloys. A 40% increase in life over the TiAlN benchmark coating was found. Further evaluations of these coatings with commercialization partners are currently in progress.

Hard processes in hadronic interactions

International Nuclear Information System (INIS)

Satz, H.; Wang, X.N.

1995-01-01

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

Experimental Study of Bilinear Initiating System Based on Hard Rock Pile Blasting

Directory of Open Access Journals (Sweden)

Yusong Miao

2017-01-01

Full Text Available It is difficult to use industrial explosives to excavate hard rock and achieve suitable blasting effect due to the low energy utilization rate resulting in large rocks and short blasting footage. Thus, improving the utilization ratio of the explosive energy is important. In this study, a novel bilinear initiation system based on hard rock blasting was proposed to improve the blasting effects. Furthermore, on the basis of the detonation wave collision theory, frontal collision, oblique reflection, and Mach reflection during detonation wave propagation were studied. The results show that the maximum detonation pressure at the Mach reflection point where the incident angle is 46.9° is three times larger than the value of the explosive complete detonation. Then, in order to analyze the crack propagation in different initiation forms, a rock fracture test slot was designed, and the results show that bilinear initiating system can change the energy distribution of explosives. Finally, field experiment was implemented at the hard rock pile blasting engineering, and experimental results show that the present system possesses high explosive energy utilization ratio and low rock fragments size. The results of this study can be used to improve the efficiency in hard rock blasting.

Theory of hard diffraction and rapidity gaps

International Nuclear Information System (INIS)

Del Duca, V.

1995-06-01

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). (orig.)

The Effect of Water Hardness on Mortality of Zebrafish (Danio rerio) During Exposure to Oxytetracycline.

Science.gov (United States)

Hundt, Matthias; Schreiber, Benjamin; Eckmann, Reiner; Lunestad, Bjørn Tore; Wünneman, Hannah; Schulz, Ralf

2016-02-01

Marking of fish otoliths with oxytetracycline and tetracycline is a widely used method to evaluate the effectiveness of stocking operations. Available protocols for the labeling of fish specify a number of factors influencing mark quality and potential risk for fish during marking. This study investigates the influence of water hardness on mortality of freshwater fish during marking with OTC. In order to pursue this question complexation of OTC with Mg(2+) and Ca(2+) cations was measured spectrophotometrically. Furthermore, zebrafish (Danio rerio) were immersed in OTC solutions (1200 mg/L; 48 h immersion) combined with varying levels of water hardness (5.5, 15.5, 25.5, 32.5°dH). The amount of OTC-Mg-Ca-complexes was positively correlated to water hardness. Moreover, it could be demonstrated that mortality of zebrafish during marking varied as a factor of water hardness. Highest mortalities occurred at the lowest (5.5°dH) and the highest (32.5°dH) tested levels during marking with OTC.

Newly developed hardness testing system, "Cariotester": measurement principles and development of a program for measuring Knoop hardness of carious dentin.

Science.gov (United States)

Shimizu, Akihiko; Nakashima, Syozi; Nikaido, Toru; Sugawara, Toyotaro; Yamamoto, Takatsugu; Momoi, Yasuko

2013-01-01

We previously discovered that when a cone-shaped indenter coated with paint was pressed into an object, the paint disappeared in accordance with the depth of the indentation. Based on this fact, we developed the Cariotester, a portable system for measuring the Knoop hardness (KHN) of carious dentin. The Cariotester is composed of a handpiece with an indenter, a microscope, and a computer. In this system, the painted indenter is forced into the material with a 150-gf load, and the indentation depth (CT depth) is obtained from the paint disappearance. The CT depth by the Cariotester and the KHN by a microhardness tester were determined at 14 dentin regions. From the data, a program was created to convert the CT depth of the carious dentin into the KHN. As a result, if the CT depth is measured with this system, the KHN of carious dentin can be displayed in real time.

Rotation of hard particles in a soft matrix

Science.gov (United States)

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

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

The Variable Crab Nebula: Evidence for a Connection Between GeV Flares and Hard X-ray Variations

Science.gov (United States)

Wilson-Hodge, Colleen A.; Harding, A. K.; Hays, E. A.; Cherry, M. L.; Case, G. L.; Finger, M. H.; Jenke, P.; Zhang, X.

2016-01-01

In 2010, hard X-ray variations (Wilson-Hodge et al. 2011) and GeV flares (Tavani et al 2011, Abdo et al. 2011) from the Crab Nebula were discovered. Connections between these two phenomena were unclear, in part because the timescales were quite different, with yearly variations in hard X-rays and hourly to daily variations in the GeV flares. The hard X-ray flux from the Crab Nebula has again declined since 2014, much like it did in 2008-2010. During both hard X-ray decline periods, the Fermi LAT detected no GeV flares, suggesting that injection of particles from the GeV flares produces the much slower and weaker hard X-ray variations. The timescale for the particles emitting the GeV flares to lose enough energy to emit synchrotron photons in hard X-rays is consistent with the yearly variations observed in hard X-rays and with the expectation that the timescale for variations slowly increases with decreasing energy. This hypothesis also predicts even slower and weaker variations below 10 keV, consistent with the non-detection of counterparts to the GeV flares by Chandra (Weisskopf et al 2013). We will present a comparison of the observed hard X-ray variations and a simple model of the decay of particles from the GeV flares to test our hypothesis.

Radiation Hard and High Light Yield Scintillator Search for CMS Phase II Upgrade

CERN Document Server

Tiras, Emrah

2015-01-01

The CMS detector at the LHC requires a major upgrade to cope with the higher instantaneous luminosity and the elevated radiation levels. The active media of the forward backing hadron calorimeters is projected to be radiation-hard, high light yield scintillation materials or similar alternatives. In this context, we have studied various radiation-hard scintillating materials such as Polyethylene Terephthalate (PET), Polyethylene Naphthalate (PEN), High Efficiency Mirror (HEM) and quartz plates with various coatings. The quartz plates are pure Cerenkov radiators and their radiation hardness has been confirmed. In order to increase the light output, we considered organic and inorganic coating materials such as p-Terphenyl (pTp), Anthracene and Gallium-doped Zinc Oxide (ZnO Ga) that are applied as thin layers on the surface of the quartz plates. Here, we present the results of the related test beam activities, laboratory measurements and recent developments.

In Situ Observation of Hard Surrounding Rock Displacement at 2400-m-Deep Tunnels

Science.gov (United States)

Feng, Xia-Ting; Yao, Zhi-Bin; Li, Shao-Jun; Wu, Shi-Yong; Yang, Cheng-Xiang; Guo, Hao-Sen; Zhong, Shan

2018-03-01

This paper presents the results of in situ investigation of the internal displacement of hard surrounding rock masses within deep tunnels at China's Jinping Underground Laboratory Phase II. The displacement evolution of the surrounding rock during the entire excavation processes was monitored continuously using pre-installed continuous-recording multi-point extensometers. The evolution of excavation-damaged zones and fractures in rock masses were also observed using acoustic velocity testing and digital borehole cameras, respectively. The results show four kinds of displacement behaviours of the hard surrounding rock masses during the excavation process. The displacement in the inner region of the surrounding rock was found to be greater than that of the rock masses near the tunnel's side walls in some excavation stages. This leads to a multi-modal distribution characteristic of internal displacement for hard surrounding rock masses within deep tunnels. A further analysis of the evolution information on the damages and fractures inside the surrounding rock masses reveals the effects of excavation disturbances and local geological conditions. This recognition can be used as the reference for excavation and supporting design and stability evaluations of hard-rock tunnels under high-stress conditions.

Reading characteristics of deaf and hard-of-hearing pupils

Directory of Open Access Journals (Sweden)

Karić Jasmina

2012-01-01

Full Text Available Background/Aim. Speech motor mechanisms play a crucial role in the process of demutization, due to the fact that they cover all the elements of the successive development of spech production movements leading to speech formation (socalled kinesthesia in speach. The aim of this study was to estimate the impact of perceptual motor actions on the cognitive process of reading in 130 students in regular schools and schools for the deaf and hard-of-hearing children in the Republic of Serbia. Methods. Kostić and Vladisavljević test consisted of the ten levels weight was used for the assessment of reading speed. To assess understanding of text read by verbal responses, we used three-dimensional adapted reading test of Helene Sax. Results. The triage-articulation test for assessing reading speed (Kostić and Vladisavljević’s test according to the weight of ten levels, revealed that students in regular schools statistically significantly faster read texts as compared to the deaf students. The results of the threedimensional adapted reading test of Helena Sax, show that the words learned by deaf children exist in isolation in their mind, ie, if there is no standard of acoustic performance for graphic image, in deaf child every word, printed or written, is just the sum of letters without meaning. Conclusion. There is a significant difference in text reading speed and its understanding among the children who hear and the deaf and hard of-hearing children. It is essential that in deaf and heard-of hearing children education, apart from the development of speech, parallelly use the concept of semantic processing in order to get each word by the fullness of its content and the possibility of expanding its meaning in a variety of assets.

[Reading characteristics of deaf and hard-of-hearing pupils].

Science.gov (United States)

Karić, Jasmina; Ristić, Sinisa; Medenica, Snezana; Tadić, Vaska; Slavnić, Svetlana

2012-10-01

Speech motor mechanisms play a crucial role in the process of demutization, due to the fact that they cover all the elements of the successive development of spech production movements leading to speech formation (so-called kinesthesia in speach). The aim of this study was to estimate the impact of perceptual motor actions on the cognitive process of reading in 130 students in regular schools and schools for the deaf and hard-of-hearing children in the Republic of Serbia. Kostić and Vladisavljević test consisted of the ten levels weight was used for the assessment of reading speed. To assess understanding of text read by verbal responses, we used three-dimensional adapted reading test of Helene Sax. The triage-articulation test for assessing reading speed (Kostié and Vladisavljević's test according to the weight of ten levels, revealed that students in regular schools statistically significantly faster read texts as compared to the deaf students. The results of the three-dimensional adapted reading test of Helena Sax, show that the words learned by deaf children exist in isolation in their mind, i.e., if there is no standard of acoustic performance for graphic image, in deaf child every word, printed or written, is just the sum of letters without meaning. There is a significant difference in text reading speed and its understanding among the children who hear and the deaf and hard-of-hearing children. It is essential that in deaf and heard-of-hearing children education, apart from the development of speech, parallelly use the concept of semantic processing in order to get each word by the fullness of its content and the possibility of expanding its meaning in a variety of assets.

Methods of improvement in hardness of composite surface layer on cast steel

Directory of Open Access Journals (Sweden)

J. Szajnar

2008-08-01

Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in founding process a composite surface layer on the basis of Fe-Cr-C alloy and next its remelting with use of welding technology TIG – Tungsten Inert Gas. Technology of composite surface layer guarantee mainly increase in hardness and abrasive wear resistance of cast steel castings on machine elements. This technology can be competition for generally applied welding technology (surfacing by welding and thermal spraying. However the results of studies show, that is possible to connection of both methods founding and welding of surface hardening of cast steel castings. In range of experimental plan was made test castings with composite surface layer, which next were remelted with energy 0,8 and 1,6 kJ/cm. Usability for industrial applications of test castings was estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

Theory of hard diffraction and rapidity gaps

International Nuclear Information System (INIS)

Del Duca, V.

1996-01-01

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

Hard X-ray studies on the Castor tokamak

International Nuclear Information System (INIS)

Mlynar, J.

1990-04-01

The electron runaway processes in tokamaks are discussed with regard to hard X radiation measurements. The origin and confinement of runaway electrons, their bremsstrahlung spectra and the influence of lower hybrid current drive on the distribution of high-energy electrons are analyzed for the case of the Castor tokamak. The hard X-ray spectrometer designed for the Castor tokamak is also described and preliminary qualitative results of hard X-ray measurements are presented. The first series of integral measurements made it possible to map the azimuthal dependence of the hard X radiation

Effect of current and travel speed variation of TIG welding on microstructure and hardness of stainless steel SS 316L

Science.gov (United States)

Jatimurti, Wikan; Abdillah, Fakhri Aulia; Kurniawan, Budi Agung; Rochiem, Rochman

2018-04-01

One of the stainless steel types that widely used in industry is SS 316L, which is austenitic stainless steel. One of the welding methods to join stainless steel is Tungsten Inert Gas (TIG), which can affect its morphology, microstructure, strength, hardness, and even lead to cracks in the weld area due to the given heat input. This research has a purpose of analyzing the relationship between microstructure and hardness value of SS 316L stainless steel after TIG welding with the variation of current and travel speed. The macro observation shows a distinct difference in the weld metal and base metal area, and the weld form is not symmetrical. The metallographic test shows the phases that formed in the specimen are austenite and ferrite, which scattered in three welding areas. The hardness test showed that the highest hardness value found in the variation of travel speed 12 cm/min with current 100 A. Welding process and variation were given do not cause any defects in the microstructure, such as carbide precipitation and sigma phase, means that it does not affect the hardness and corrosion resistance of all welded specimen.

Influence of light-curing units and restorative materials on the micro hardness of resin cements

Directory of Open Access Journals (Sweden)

Kuguimiya Rosiane

2010-01-01

Full Text Available Aim: The aim of this study was to evaluate the effect of indirect restorative materials (IRMs and light-curing units (LCUs on the micro hardness of dual-cured resin cement. Materials and Methods: A total of 36 cylindrical samples (2 mm thick were prepared with dual-cured resin cement (Relyx ARC photo-activated with either a QTH (Optilight Plus for 40s or a LED (Radii light-curing unit for 65s. Photo-activation was performed through the 2-mm- thick IRMs and the samples were divided into six groups (n=6 according to the combination of veneering materials (without, ceramic and indirect resin and LCUs (QTH and LED. In the control group, the samples were light-cured with a QTH unit without the interposition of any restorative material. Vickers micro hardness test was performed on the top and bottom surfaces of each sample (load of 50 g for 15 secs. The data were statistically analyzed using a three-way ANOVA followed by Tukey x s post-hoc test ( P < 0.05. Results: There were no statistically significant differences on the top surface between the light curing-units ( P > 0.05; however, the LED provided greater hardness on the bottom surface when a ceramic material was used ( P < 0.05. The mean hardness in photo-activated samples, in which there was no interposition of indirect materials, was significantly greater ( P < 0.01. Conclusions: It may be concluded that the interposition of the restorative material decreased the micro hardness in the deeper cement layer. Such decrease, however, was lower when the ceramic was interposed and the cement light-cured with LED.

The Effect of Food-Simulating Agents on the Bond Strength of Hard Chairside Reline Materials to Denture Base Resin.

Science.gov (United States)

Fatemi, Farzaneh Sadat; Vojdani, Mahroo; Khaledi, Amir Ali Reza

2018-06-08

To investigate the influence of food-simulating agents on the shear bond strength between direct hard liners and denture base acrylic resin. In addition, mode of failure was evaluated. One hundred fifty cylindrical columns of denture base resin were fabricated and bonded to three types of hard reline materials (Hard GC Reline, Tokuyama Rebase II Fast, TDV Cold Liner Rebase). Specimens of each reline material were divided into five groups (n = 10) to undergo 12-day immersion in distilled water, 0.02 N citric acid aqueous solution, heptane, and 40% ethanol/water solution at 37°C. The control group was not immersed in any solution. The shear bond strength test was performed, and the failure mode was determined. Statistics were analyzed with two-way ANOVA and chi-square test (α = 0.05). Significant interaction was found between the hard liners and food simulating agents (p < 0.001). The shear bond strength of Tokuyama in 40% ethanol and TDV in heptane decreased significantly (p = 0.001, p < 0.001 respectively); however, none of the solutions could significantly affect the shear bond strength of Hard GC Reline (p = 0.208). The mixed failure mode occurred more frequently in Hard GC Reline compared with the other liners (p < 0.001) and was predominant in specimens with higher bond strength values (p = 0.012). Food simulating agents did not adversely affect the shear bond strength of Hard GC Reline; however, ethanol and heptane decreased the bond strength of Tokuyama and TDV, respectively. These findings may provide support to dentists to recommend restricted consumption of some foods and beverages for patients who have to use dentures relined with certain hard liners. © 2018 by the American College of Prosthodontists.

Breakdown characteristics in DC spark experiments of copper focusing on purity and hardness

CERN Document Server

Yokoyama, Kazue; Higashi, Yasuo; Higo, Toshi; Matsumoto, Shuji; Santiago-Kern, Ana Rocia; Pasquino, Chiara; Calatroni, Sergio; Wuensch, Walter

2010-01-01

The breakdown characteristics related to the differences in purity and hardness were investigated for several types of copper using a DC spark test system. Three types of oxygen-free copper (OFC) materials, usual class 1 OFC 7-nine large-grain copper and 6-nine hot-isotropic-pressed (HIP) copper with/without diamond finish, were tested with the DC spark test system. The measurements of the beta, breakdown fields, and breakdown probability are presented and discussed in this paper.

Diamond-like carbon coatings enhance the hardness and resilience of bearing surfaces for use in joint arthroplasty.

Science.gov (United States)

Roy, M E; Whiteside, L A; Xu, J; Katerberg, B J

2010-04-01

The purpose of this study was to evaluate the potential of a hard diamond-like carbon (DLC) coating to enhance the hardness and resilience of a bearing surface in joint replacement. The greater hardness of a magnesium-stabilized zirconium (Mg-PSZ) substrate was expected to provide a harder coating-substrate composite microhardness than the cobalt-chromium alloy (CoCr) also used in arthroplasty. Three femoral heads of each type (CoCr, Mg-PSZ, DLC-CoCr and DLC-Mg-PSZ) were examined. Baseline (non-coated) and composite coating/substrate hardness was measured by Vickers microhardness tests, while nanoindentation tests measured the hardness and elastic modulus of the DLC coating independent of the Mg-PSZ and CoCr substrates. Non-coated Mg-PSZ heads were considerably harder than non-coated CoCr heads, while DLC coating greatly increased the microhardness of the CoCr and Mg-PSZ substrates. On the nanoscale the non-coated heads were much harder than on the microscale, with CoCr exhibiting twice as much plastic deformation as Mg-PSZ. The mechanical properties of the DLC coatings were not significantly different for both the CoCr and Mg-PSZ substrates, producing similar moduli of resilience and plastic resistance ratios. DLC coatings greatly increased hardness on both the micro and nano levels and significantly improved resilience and resistance to plastic deformation compared with non-coated heads. Because Mg-PSZ allows less plastic deformation than CoCr and provides a greater composite microhardness, DLC-Mg-PSZ will likely be more durable for use as a bearing surface in vivo. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Hard exclusive QCD processes

Energy Technology Data Exchange (ETDEWEB)

Kugler, W.

2007-01-15

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

Soft and hard pomerons

International Nuclear Information System (INIS)

Maor, Uri; Tel Aviv Univ.

1995-09-01

The role of s-channel unitarity screening corrections, calculated in the eikonal approximation, is investigated for soft Pomeron exchange responsible for elastic and diffractive hadron scattering in the high energy limit. We examine the differences between our results and those obtained from the supercritical Pomeron-Regge model with no such corrections. It is shown that screening saturation is attained at different scales for different channels. We then proceed to discuss the new HERA data on hard (PQCD) Pomeron diffractive channels and discuss the relationship between the soft and hard Pomerons and the relevance of our analysis to this problem. (author). 18 refs, 9 figs, 1 tab

Soft And Hard Skills of Social Worker

OpenAIRE

HANTOVÁ, Libuše

2011-01-01

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

40 CFR 63.344 - Performance test requirements and test methods.

Science.gov (United States)

2010-07-01

... electroplating tanks or chromium anodizing tanks. The sampling time and sample volume for each run of Methods 306... Chromium Anodizing Tanks § 63.344 Performance test requirements and test methods. (a) Performance test... Emissions From Decorative and Hard Chromium Electroplating and Anodizing Operations,” appendix A of this...

Standard Test Method for Application of Ionization Chambers to Assess the Low Energy Gamma Component of Cobalt-60 Irradiators Used in Radiation-Hardness Testing of Silicon Electronic Devices

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 Low energy components in the photon energy spectrum of Co-60 irradiators lead to absorbed dose enhancement effects in the radiation-hardness testing of silicon electronic devices. These low energy components may lead to errors in determining the absorbed dose in a specific device under test. This method covers procedures for the use of a specialized ionization chamber to determine a figure of merit for the relative importance of such effects. It also gives the design and instructions for assembling this chamber. 1.2 This method is applicable to measurements in Co-60 radiation fields where the range of exposure rates is 7 × 10 −6 to 3 × 10−2 C kg −1 s−1 (approximately 100 R/h to 100 R/s). For guidance in applying this method to radiation fields where the exposure rate is >100 R/s, see Appendix X1. Note 1—See Terminology E170 for definition of exposure and its units. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information onl...

Emerging role of HPV self-sampling in cervical cancer screening for hard-to-reach women: Focused literature review.

Science.gov (United States)

Madzima, Tina R; Vahabi, Mandana; Lofters, Aisha

2017-08-01

To provide a focused critical review of the literature on the acceptability, feasibility, and uptake of human papillomavirus (HPV) self-sampling among hard-to-reach women. A focused search to obtain relevant literature published in English between 1997 and 2015 was done using PubMed and EMBASE using search terms including HPV self-test or HPV self-sample or HPV kit in combination with acceptability or feasibility . Only studies that focused on never-screened or underscreened populations were included in this review. Human papillomavirus self-sampling was found to be highly acceptable and feasible among these hard-to-reach women across most studies. Mailing of self-sampling kits has been shown to increase participation among hard-to reach women. Some concerns remain regarding adherence to further follow-up among high-risk women with positive test results for HPV after screening. There is a strong body of evidence to support the usefulness of HPV self-sampling in increasing participation of hard-to-reach women in screening programs (level I evidence). Convenience, privacy, ease of use, and, likely, cost-effectiveness of HPV self-sampling are driving forces in its emerging role in cervical cancer screening among hard-to-reach women. Key barriers to participation could be addressed by overcoming disparities in HPV-related knowledge and perceptions about cervical cancer screening. Copyright© the College of Family Physicians of Canada.

The pedagogical effect of a health education application for deaf and hard of hearing students in elementary schools.

Science.gov (United States)

Abbasi, Masoumeh; Eslami, Saeid; Mohammadi, Mahdi; Khajouei, Reza

2017-09-01

Deaf or hard-of-hearing children experience difficulties in learning health principles. But technology has significantly improved their ability to learn. The challenge in e-learning is to design attractive applications while having an educational aspect. The aims of this study were to determine the pedagogical effectiveness of a health education application for deaf and hard of hearing students in elementary schools, and to investigate the student's perceptions in different educational grades about the educational effectiveness of the text, graphics, video clips, and animation in the application. The study design was quasi experimental and was conducted in Mashhad in 2016. Study population were deaf or hard-of-hearing students in elementary schools. The intervention included health application training to deaf and hard-of-hearing students in Mashhad. A questionnaire was used for data gathering. The pedagogical effectiveness was determined by measuring the modified Adapted Pedagogical Index. This index was created based on the characteristics of the application and study population. Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests with Bonferroni adjustment by SPSS 22. Eighty-two students participated in the intervention. The value of modified Adapted Pedagogical Index was 0.669, indicating that the application was effective. The results of Kruskal-Wallis H and Mann-Whitney U test showed significant differences in different educational grades. (pinformation technology can improve the education of deaf and hard-of-hearing students. Modified Adapted Pedagogical Index can be used for evaluation of non-interactive applications for elementary school children who are deaf or hard of hearing.

Determination of Formula for Vickers Hardness Measurements Uncertainty

International Nuclear Information System (INIS)

Purba, Asli

2007-01-01

The purpose of formula determination is to obtain the formula of Vickers hardness measurements uncertainty. The approach to determine the formula: influenced parameters identification, creating a cause and effect diagram, determination of sensitivity, determination of standard uncertainty and determination of formula for Vickers hardness measurements uncertainty. The results is a formula for determination of Vickers hardness measurements uncertainty. (author)

Selecting Optimal Random Forest Predictive Models: A Case Study on Predicting the Spatial Distribution of Seabed Hardness

Science.gov (United States)

Li, Jin; Tran, Maggie; Siwabessy, Justy

2016-01-01

Spatially continuous predictions of seabed hardness are important baseline environmental information for sustainable management of Australia’s marine jurisdiction. Seabed hardness is often inferred from multibeam backscatter data with unknown accuracy and can be inferred from underwater video footage at limited locations. In this study, we classified the seabed into four classes based on two new seabed hardness classification schemes (i.e., hard90 and hard70). We developed optimal predictive models to predict seabed hardness using random forest (RF) based on the point data of hardness classes and spatially continuous multibeam data. Five feature selection (FS) methods that are variable importance (VI), averaged variable importance (AVI), knowledge informed AVI (KIAVI), Boruta and regularized RF (RRF) were tested based on predictive accuracy. Effects of highly correlated, important and unimportant predictors on the accuracy of RF predictive models were examined. Finally, spatial predictions generated using the most accurate models were visually examined and analysed. This study confirmed that: 1) hard90 and hard70 are effective seabed hardness classification schemes; 2) seabed hardness of four classes can be predicted with a high degree of accuracy; 3) the typical approach used to pre-select predictive variables by excluding highly correlated variables needs to be re-examined; 4) the identification of the important and unimportant predictors provides useful guidelines for further improving predictive models; 5) FS methods select the most accurate predictive model(s) instead of the most parsimonious ones, and AVI and Boruta are recommended for future studies; and 6) RF is an effective modelling method with high predictive accuracy for multi-level categorical data and can be applied to ‘small p and large n’ problems in environmental sciences. Additionally, automated computational programs for AVI need to be developed to increase its computational efficiency and

Hard scattering and a diffractive trigger

International Nuclear Information System (INIS)

Berger, E.L.; Collins, J.C.; Soper, D.E.; Sterman, G.

1986-02-01

Conclusions concerning the properties of hard scattering in diffractively produced systems are summarized. One motivation for studying diffractive hard scattering is to investigate the interface between Regge theory and perturbative QCD. Another is to see whether diffractive triggering can result in an improvement in the signal-to-background ratio of measurements of production of very heavy quarks. 5 refs

Complex technique for materials hardness measurement

Energy Technology Data Exchange (ETDEWEB)

Krashchenko, V P; Oksametnaya, O B

1984-01-01

A review of existing methods of measurement of material hardness in national and foreign practice has been made. A necessity of improving the technique of material hardness measurement in a wide temperature range and insuring load change with indenting, continuity of imprint application, smooth changing of temperatures along a sample length, and deformation rate control has been noted.

Seismic loads in modularized and unmodularized large pools located on hard or intermediate hard sites

Energy Technology Data Exchange (ETDEWEB)

Dong, R G [California Univ., Livermore (USA). Lawrence Livermore Lab.

1977-12-01

To augment the present capacity of pools for storing spent nuclear fuel elements, pools larger than those in current use are being planned. These pools may or may not be modularized into cells. Because of the large size of the pools, seismic loads are of significant interest. In particular, the effects of modularization and site hardness are of concern. The study presented in this paper reveals that modularization is generally unfavourable, because it creates the option of leaving one or more cells empty which in turn results in higher structural loads. The wall which separates a filled cell from an empty cell, or the wall which bears against earth on one side and faces an empty cell on the other, becomes very highly stressed. For the particular pool geometries examined, a hard site is generally preferred over an intermediate hard site in terms of structural loads.

Micro-computer cards for hard industrial environment

Energy Technology Data Exchange (ETDEWEB)

Breton, J M

1984-03-15

Approximately 60% of present or future distributed systems have, or will have, operational units installed in hard environments. In these applications, which include canalization and industrial motor control, robotics and process control, systems must be easily applied in environments not made for electronic use. The development of card systems in this hard industrial environment, which is found in petrochemical industry and mines is described. National semiconductor CIM card system CMOS technology allows the real time micro computer application to be efficient and functional in hard industrial environments.

Aespoe Hard Rock Laboratory Annual Report 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-08-01

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

Aespoe Hard Rock Laboratory Annual Report 1999

International Nuclear Information System (INIS)

2000-08-01

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

Effect of different types of disinfection solution and aging on the hardness and colour stability of maxillofacial silicone elastomers.

Science.gov (United States)

Cevik, Pinar; Yildirim-Bicer, Arzu Z

2017-11-09

Understanding the effect of aging and different disinfecting agents on the physical properties of pigmented maxillofacial silicones may help eliminate the current uncertainty as to the best follow-up suggestions for the patients treated with silicone prostheses. One hundred fifty specimens (14 × 2 mm) were evaluated for colour and 75 specimens (30 × 10 mm) for hardness (total, 225 specimens). Five specimens were used for hardness testing in each disinfecting solution while 10 silicone specimens were used for colour evaluation. The samples were separated into 5 groups and the initial hardness and colour evaluations were performed and placed in disinfectant solution (neutral soap, effervescent tablet, 0.2% chlorhexidine, 4% chlorhexidine, sodium hypochlorite). A second set of colour and hardness measurements was taken after 48 hours of disinfection and 1,008 hours of artificial aging in a QUV-accelerated weathering tester. Two-way and 1-way analysis of variance with Tukey tests and paired t-test were used for statistical analysis (α = 0.05). Before artificial aging, the hardness value of the red pigment group was found to be significantly lower than that of the brown pigment group. After aging, the lowest Shore A value was seen in the neutral soap group, while the highest was seen in the effervescent tablet. Based on the results of this study, chlorohexidine 0.2% was found to be most suitable agent for disinfection of the prostheses. Washing with neutral soap caused loss of pigment from the surface of the silicones. Sodium hypochlorite was found to have a colour-fading effect on silicone specimens.

Transport coefficients and mechanical response in hard-disk colloidal suspensions

International Nuclear Information System (INIS)

Zhang Bo-Kai; Ma Yu-Qiang; Li Jian; Chen Kang; Tian Wen-De

2016-01-01

We investigate the transport properties and mechanical response of glassy hard disks using nonlinear Langevin equation theory. We derive expressions for the elastic shear modulus and viscosity in two dimensions on the basis of thermal-activated barrier-hopping dynamics and mechanically accelerated motion. Dense hard disks exhibit phenomena such as softening elasticity, shear-thinning of viscosity, and yielding upon deformation, which are qualitatively similar to dense hard-sphere colloidal suspensions in three dimensions. These phenomena can be ascribed to stress-induced “landscape tilting”. Quantitative comparisons of these phenomena between hard disks and hard spheres are presented. Interestingly, we find that the density dependence of yield stress in hard disks is much more significant than in hard spheres. Our work provides a foundation for further generalizing the nonlinear Langevin equation theory to address slow dynamics and rheological behavior in binary or polydisperse mixtures of hard or soft disks. (rapid communication)

Long term test of buffer material at the Aespoe Hard Rock Laboratory, LOT project. Final report on the A2 test parcel

Energy Technology Data Exchange (ETDEWEB)

Karnland, Ola; Olsson, Siv; Dueck, Ann; Birgersson, Martin; Nilsson, Ulf; Hernan-Haakansson, Tania (Clay Technology AB, Lund (Sweden)); Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden); Goeteborg Univ., Dept. of Cell and Molecular Biology, Goeteborg (Sweden)); Nilsson, Sara; Eriksen, Trygve E. (School of Chemical Science and Engineering, Nuclear chemistry, Royal Inst. of Tech., Stockholm (Sweden)); Rosborg, Bo (Rosborg Consulting, Nykoeping (Sweden))

2009-11-15

In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, are expected to result in minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory (HRL) are focused on identifying and quantifying such mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks with a diameter of 30 cm, and gauges for temperature, total pressure, water pressure and humidity. Electrical heaters placed inside the copper tube are used to simulate the power from the decaying spent fuel. Three parcels are exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and four parcels to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (>5 years) and long term tests (>10 years). The present report concerns the A2 test parcel, which was a medium term test exposed to adverse conditions. Cu-coupons, 60Co tracers, bacteria and specific chemical substances were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at test site and the bentonite material was sampled for specified analyses performed by nine different laboratories in five countries. The main aspects of the various tests and analyses may be summarized in the following items: - physical

Standard Reference Development of nuclear material for Tensile and Hardness Test Properties

International Nuclear Information System (INIS)

Choo, Y. S.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Baik, S. J.; Chun, Y. B.; Kim, K. H.; Hong, K. P.; Ryu, W. S.

2007-12-01

Standard reference is a official approved data such a coefficient of physics, approved material properties, and etc., which should be analyzed and evaluated by scientific method to acquire official approval for accuracy and credibility of measured data and information. So it could be used broadly and continuously by various fields of nation and society. It is classified to effective standard reference, verified standard reference, and certified standard reference. There are sixteen fields in designated standard references such a physical chemistry field, material field, metal field, and the others. The standard reference of neutron irradiated nuclear structural material is classified to metal field. This report summarized the whole processes about data collection, data production, data evaluation and the suggestion of details evaluation technical standard for tensile and hardness properties, which were achieved by carry out the project 'nuclear material standard reference development' as a result

Standard Reference Development of nuclear material for Tensile and Hardness Test Properties

Energy Technology Data Exchange (ETDEWEB)

Choo, Y. S.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Baik, S. J.; Chun, Y. B.; Kim, K. H.; Hong, K. P.; Ryu, W. S

2007-12-15

Standard reference is a official approved data such a coefficient of physics, approved material properties, and etc., which should be analyzed and evaluated by scientific method to acquire official approval for accuracy and credibility of measured data and information. So it could be used broadly and continuously by various fields of nation and society. It is classified to effective standard reference, verified standard reference, and certified standard reference. There are sixteen fields in designated standard references such a physical chemistry field, material field, metal field, and the others. The standard reference of neutron irradiated nuclear structural material is classified to metal field. This report summarized the whole processes about data collection, data production, data evaluation and the suggestion of details evaluation technical standard for tensile and hardness properties, which were achieved by carry out the project 'nuclear material standard reference development' as a result.

The effect of acidulated phosphate fluoride application on dental enamel surfaces hardness

Directory of Open Access Journals (Sweden)

Edhie Arief P

2007-09-01

Full Text Available Enamel demineralization by acid is the first step of caries process. It has recently been shown that acidulated phosphate fluoride (APF can maintain the hardness of enamel surface. The aim of this study was examine the effect of APF application in the hardest of enamel surface. Fifty extracted teeth were cut at their crown, 40 teeth were taken randomly then divided into 4 groups, group 1 as the control, group 2 was treated with APF for 1 minute, group 3 for 4 minutes and group 4 for 7 minutes, then all the samples were washed with demineralized water. To see the effect of APF, all of the samples were soaked in lactic acid demineralization solution with pH 4,5 for 72 hours., the hardness of the surfaces of those samples before and after the treatment was measured by Micro Vickers Hardness Tester. The data were analyzed using One-Way ANOVA and LSD tests. In conclusion, 1.23% APF gel can reduce higher enamel demineralization.

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

Directory of Open Access Journals (Sweden)

Chetan Patil

2016-07-01

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

Semiconductor testing method

International Nuclear Information System (INIS)

Brown, Stephen.

1992-01-01

In a method of avoiding use of nuclear radiation, eg gamma rays, X-rays, electron beams, for testing semiconductor components for resistance to hard radiation, which hard radiation causes data corruption in some memory devices and 'latch-up' in others, similar fault effects can be achieved using a xenon or other 'light' flash gun even though the penetration of light is significantly less than that of gamma rays. The method involves treating a device with gamma radiation, measuring a particular fault current at the onset of a fault event, repeating the test with light to confirm the occurrence of the fault event at the same measured fault current, and using the fault current value as a reference for future tests using light on similar devices. (author)

CMOS optimization for radiation hardness

International Nuclear Information System (INIS)

Derbenwick, G.F.; Fossum, J.G.

1975-01-01

Several approaches to the attainment of radiation-hardened MOS circuits have been investigated in the last few years. These have included implanting the SiO 2 gate insulator with aluminum, using chrome-aluminum layered gate metallization, using Al 2 O 3 as the gate insulator, and optimizing the MOS fabrication process. Earlier process optimization studies were restricted primarily to p-channel devices operating with negative gate biases. Since knowledge of the hardness dependence upon processing and design parameters is essential in producing hardened integrated circuits, a comprehensive investigation of the effects of both process and design optimization on radiation-hardened CMOS integrated circuits was undertaken. The goals are to define and establish a radiation-hardened processing sequence for CMOS integrated circuits and to formulate quantitative relationships between process and design parameters and the radiation hardness. Using these equations, the basic CMOS design can then be optimized for radiation hardness and some understanding of the basic physics responsible for the radiation damage can be gained. Results are presented

Materials testing 1985

International Nuclear Information System (INIS)

1985-01-01

The following subjects were dealt with at the meeting: Testing with vibration loads; Hardness testing; Calibration of test devices and equipment; Test technique for compound materials; Vibration strength testing and expense of experiments; Solving problems in introducing forces into samples and components and process of ambulant materials testing. There are 17 separate abstracts from among 43 lectures. (orig./PW) [de

Study of Cu-Al-Zn alloys hardness temperature dependence

International Nuclear Information System (INIS)

Kurmanova, D.T.; Skakov, M.K.; Melikhov, V.D.

2001-01-01

In the paper the results of studies for the Cu-Al-Zn ternary alloys hardness temperature dependence are presented. The method of 'hot hardness' has been used during study of the solid state phase transformations and under determination of the hot stability boundaries. Due to the samples brittleness a hardness temperature dependence definition is possible only from 350-400 deg. C. Sensitivity of the 'hot hardness' method is decreasing within high plasticity range, so the measurements have been carried out only up to 700-800 deg. C. It is shown, that the alloys hardness dependence character from temperature is close to exponential one within the certain structure modification existence domain

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

Science.gov (United States)

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".

Visual inspection technology in the hard disc drive industry

CERN Document Server

Muneesawang, Paisarn

2015-01-01

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

Hardness of basaltic glass-ceramics

DEFF Research Database (Denmark)

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

2009-01-01

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

Hard template synthesis of metal nanowires

Science.gov (United States)

Kawamura, Go; Muto, Hiroyuki; Matsuda, Atsunori

2014-11-01

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.

Why Are Drugs So Hard to Quit?

Medline Plus

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

Reliability evaluation of hard disk drive failures based on counting processes

International Nuclear Information System (INIS)

Ye, Zhi-Sheng; Xie, Min; Tang, Loon-Ching

2013-01-01

Reliability assessment for hard disk drives (HDDs) is important yet difficult for manufacturers. Motivated by the fact that the particle accumulation in the HDDs, which accounts for most HDD catastrophic failures, is contributed from the internal and external sources, a counting process with two arrival sources is proposed to model the particle cumulative process in HDDs. This model successfully explains the collapse of traditional ALT approaches for accelerated life test data. Parameter estimation and hypothesis tests for the model are developed and illustrated with real data from a HDD test. A simulation study is conducted to examine the accuracy of large sample normal approximations that are used to test existence of the internal and external sources.

Aespoe Hard Rock Laboratory. Annual report 1998

International Nuclear Information System (INIS)

1999-05-01

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

Aespoe Hard Rock Laboratory. Annual report 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

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

Indentation modulus and hardness of viscoelastic thin films by atomic force microscopy: A case study

International Nuclear Information System (INIS)

Passeri, D.; Bettucci, A.; Biagioni, A.; Rossi, M.; Alippi, A.; Tamburri, E.; Lucci, M.; Davoli, I.; Berezina, S.

2009-01-01

We propose a nanoindentation technique based on atomic force microscopy (AFM) that allows one to deduce both indentation modulus and hardness of viscoelastic materials from the force versus penetration depth dependence, obtained by recording the AFM cantilever deflection as a function of the sample vertical displacement when the tip is pressed against (loading phase) and then removed from (unloading phase) the surface of the sample. Reliable quantitative measurements of both indentation modulus and hardness of the investigated sample are obtained by calibrating the technique through a set of different polymeric samples, used as reference materials, whose mechanical properties have been previously determined by standard indentation tests. By analyzing the dependence of the cantilever deflection versus time, the proposed technique allows one to evaluate and correct the effect of viscoelastic properties of the investigated materials, by adapting a post-experiment data processing procedure well-established for standard depth sensing indentation tests. The technique is described in the case of the measurement of indentation modulus and hardness of a thin film of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate), deposited by chronoamperometry on an indium tin oxide (ITO) substrate.

Indentation modulus and hardness of viscoelastic thin films by atomic force microscopy: A case study

Energy Technology Data Exchange (ETDEWEB)

Passeri, D., E-mail: daniele.passeri@uniroma1.it [Dipartimento di Energetica, Universita di Roma ' La Sapienza' , Via A. Scarpa 16, 00161 Roma (Italy); Bettucci, A.; Biagioni, A.; Rossi, M.; Alippi, A. [Dipartimento di Energetica, Universita di Roma ' La Sapienza' , Via A. Scarpa 16, 00161 Roma (Italy); Tamburri, E. [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma ' Tor Vergata' , Via della Ricerca Scientifica, 00133 Roma (Italy); Lucci, M.; Davoli, I. [Dipartimento di Fisica, Universita di Roma ' Tor Vergata' , Via della Ricerca Scientifica, 00133 Roma (Italy); Berezina, S. [Department of Physics, University of Zilina, 01026, Univerzitna 1 Zilina (Slovakia)

2009-11-15

We propose a nanoindentation technique based on atomic force microscopy (AFM) that allows one to deduce both indentation modulus and hardness of viscoelastic materials from the force versus penetration depth dependence, obtained by recording the AFM cantilever deflection as a function of the sample vertical displacement when the tip is pressed against (loading phase) and then removed from (unloading phase) the surface of the sample. Reliable quantitative measurements of both indentation modulus and hardness of the investigated sample are obtained by calibrating the technique through a set of different polymeric samples, used as reference materials, whose mechanical properties have been previously determined by standard indentation tests. By analyzing the dependence of the cantilever deflection versus time, the proposed technique allows one to evaluate and correct the effect of viscoelastic properties of the investigated materials, by adapting a post-experiment data processing procedure well-established for standard depth sensing indentation tests. The technique is described in the case of the measurement of indentation modulus and hardness of a thin film of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate), deposited by chronoamperometry on an indium tin oxide (ITO) substrate.

The NuSTAR view on Hard-TeV BL Lacs

Science.gov (United States)

Costamante, L.; Bonnoli, G.; Tavecchio, F.; Ghisellini, G.; Tagliaferri, G.; Khangulyan, D.

2018-05-01

Hard-TeV BL Lacs are a new type of blazars characterized by a hard intrinsic TeV spectrum, locating the peak of their gamma-ray emission in the spectral energy distribution (SED) above 2-10 TeV. Such high energies are problematic for the Compton emission, using a standard one-zone leptonic model. We study six examples of this new type of BL Lacs in the hard X-ray band with NuSTAR. Together with simultaneous observations with the Neil Gehrels Swift Observatory, we fully constrain the peak of the synchrotron emission in their SED, and test the leptonic synchrotron self-Compton (SSC) model. We confirm the extreme nature of 5 objects also in the synchrotron emission. We do not find evidence of additional emission components in the hard X-ray band. We find that a one-zone SSC model can in principle reproduce the extreme properties of both peaks in the SED, from X-ray up to TeV energies, but at the cost of i) extreme electron energies with very low radiative efficiency, ii) conditions heavily out of equipartition (by 3 to 5 orders of magnitude), and iii) not accounting for the simultaneous UV data, which then should belong to a different emission component, possibly the same as the far-IR (WISE) data. We find evidence of this separation of the UV and X-ray emission in at least two objects. In any case, the TeV electrons must not "see" the UV or lower-energy photons, even if coming from different zones/populations, or the increased radiative cooling would steepen the VHE spectrum.

Hard diffraction and small-x

International Nuclear Information System (INIS)

Anon.

1995-01-01

In the United States, phrases such as ''small-x evolution'', ''the BFKL Pomeron'', ''deep-inelastic rapiditygap events'' and ''hard-diffraction'' do not generate the same intensity of discussion amongst high-energy physicists that they do in Europe. However, for three days in the fall such discussion filled the air at Fermilab. The ''2nd Workshop on Small-x and Diffractive Physics at the Tevatron'' was a review of the rapid theoretical and experimental progress taking place in this field. Although Quantum Chromo-dynamics (QCD) has been established as the theory of strong interactions for twenty years, as yet neither perturbative high-energy calculations nor low-energy non-perturbative techniques have been successfully extended to the mixture of high energy and low transverse momenta which characterize traditional ''soft'' diffractive processes. The simplest soft diffractive process is elastic scattering. In this case it is easiest to accept that there is an exchanged ''pomeron'', which can be pictured as a virtual entity with no electric charge or strong charge (colour), perhaps like an excitation of the vacuum. The same pomeron is expected to appear in all diffractive processes. Understanding the pomeron in QCD is a fundamental theoretical and experimental challenge. In the last two or three years the ''frontier'' in this challenging area of QCD has been pushed back significantly in both theory and experiment. Progress has been achieved by studying the evolution of hard collisions to relatively smaller constituent momenta (small x) and by studying ''hard'' diffractive collisions containing simultaneous signatures of diffraction and hard perturbative processes. The hard processes have included high transverse momentum jet production, deep inelastic lepton scattering, and (most recently) W

Experimental investigation on hard turning of AISI 4340 steel using cemented coated carbide insert

Science.gov (United States)

Pradeep Kumar, J.; Kishore, K. P.; Ranjith Kumar, M.; Saran Karthick, K. R.; Vishnu Gowtham, S.

2018-02-01

Hard turning is a developing technology that offers many potential advantages compared to grinding, which remains the standard finishing process for critical hardened surfaces. In this work, an attempt has been made to experimentally investigate hard turning of AISI 4340 steel under wet and dry condition using cemented coated carbide insert. Hardness of the workpiece material is tested using Brinell and Rockwell hardness testers. CNC LATHE and cemented coated carbide inserts of designation CNMG 120408 are used for conducting experimental trials. Significant cutting parameters like cutting speed, feed rate and depth of cut are considered as controllable input parameters and surface roughness (Ra), tool wear are considered as output response parameters. Design of experiments is carried out with the help of Taguchi’s L9 orthogonal array. Results of response parameters like surface roughness and tool wear under wet and dry condition are analysed. It is found that surface roughness and tool wear are higher under dry machining condition when compared to wet machining condition. Feed rate significantly influences the surface roughness followed by cutting speed. Depth of cut significantly influences the tool wear followed by cutting speed.

"Work smart, wear your hard hat"

CERN Multimedia

2003-01-01

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

Hard gap in epitaxial semiconductor-superconductor nanowires

DEFF Research Database (Denmark)

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

2015-01-01

a continuum of subgap states---a situation that nullifies topological protection. Here, we report a hard superconducting gap induced by proximity effect in a semiconductor, using epitaxial Al-InAs superconductor-semiconductor nanowires. The hard gap, along with favorable material properties and gate...

Microhardness Testing of Aluminum Alloy Welds

Science.gov (United States)

Bohanon, Catherine

2009-01-01

A weld is made when two pieces of metal are united or fused together using heat or pressure, and sometimes both. There are several different types of welds, each having their own unique properties and microstructure. Strength is a property normally used in deciding which kind of weld is suitable for a certain metal or joint. Depending on the weld process used and the heat required for that process, the weld and the heat-affected zone undergo microstructural changes resulting in stronger or weaker areas. The heat-affected zone (HAZ) is the region that has experienced enough heat to cause solid-state microstructural changes, but not enough to melt the material. This area is located between the parent material and the weld, with the grain structure growing as it progresses respectively. The optimal weld would have a short HAZ and a small fluctuation in strength from parent metal to weld. To determine the strength of the weld and decide whether it is suitable for the specific joint certain properties are looked at, among these are ultimate tensile strength, 0.2% offset yield strength and hardness. Ultimate tensile strength gives the maximum load the metal can stand while the offset yield strength gives the amount of stress the metal can take before it is 0.2% longer than it was originally. Both of these are good tests, but they both require breaking or deforming the sample in some way. Hardness testing, however, provides an objective evaluation of weld strengths, and also the difference or variation in strength across the weld and HAZ which is difficult to do with tensile testing. Hardness is the resistance to permanent or plastic deformation and can be taken at any desired point on the specimen. With hardness testing, it is possible to test from parent metal to weld and see the difference in strength as you progress from parent material to weld. Hardness around grain boundaries and flaws in the material will show how these affect the strength of the metal while still

Machine learning from hard x-ray surveys: applications to magnetic cataclysmic variable studies

Science.gov (United States)

Scaringi, Simone

2009-11-01

Within this thesis are discussed two main topics of contemporary astrophysics. The first is that of machine learning algorithms for astronomy whilst the second is that of magnetic cataclysmic variables (mCVs). To begin, an overview is given of ISINA: INTEGRAL Scouce Identifiction Network Algorithm. This machine learning algorithm, using random forests, is applied to the IBIS/ISGRI data set in order to ease the production of unbiased future soft gamma-ray source catalogues. The feature extraction process on an initial candidate list is described together with feature merging. Three trainng and testing sets are created in order to deal with the diverse time-scales encountered when dealing with the gamma-ray sky: one dealing with faint persistent source recognition, one dealing with strong persistent sources and a final one dealing with transients. For the latter, a new transient detection technique is introduced and described: the transient matrix. Finally the performance of the network is assessed and discussed using the testing set and some illustrative source examples. ISINA is also compared to the more conventional approach of visual inspection. Next mCVs are discussed, and in particular the properties arising from a hard X-ray selected sample which has proven remarkably efficient in detecting intermediate polars and asynchronous polars, two of the rarest type of cataclysmic variables (CVs). This thesis focuses particularly on the link between hard X-ray properties and spin/orbital periods. To this end, a new sample of these objects is constructed by cross-corelating candidate sources detected in INTEGRAL/IBIS observations against catalogues of known CVs. Also included in the analysis are hard X-ray Observations from Swift/BAT and SUZAKU/HXD in order to make the study more complete. It is found that most hard X-ray detected mCVs have Pspin/Porb<0.1 above the period gap. In this respect, attention is given to the very low number of detected systems in any ban

Development of radiation hard scintillators

International Nuclear Information System (INIS)

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

1992-05-01

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

Hard Distraction and Deep Inelastic Scattering

International Nuclear Information System (INIS)

BJORKEN, J.D.

1994-01-01

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

Effect of conventional and sugar free pediatric syrup formulations on primary tooth enamel hardness: An in vitro study

Directory of Open Access Journals (Sweden)

Gaurao Vasant Mali

2015-01-01

Full Text Available Objectives: To assess and compare the effect of conventional and sugar free pediatric syrup formulations on primary tooth enamel hardness over a period of 14 days. Materials and Methods: An in vitro study was done on 40 noncarious deciduous teeth. 10 teeth in each group were dipped in 4 pediatric medicinal syrups (1 sugarfree and 3 conventional for 1 min thrice daily for 14 days and the enamel surface micro hardness was checked at baseline, 7 th day and 14 th day by Vickers hardness testing machine. The pH, titratable acidity and buffering capacity of the syrups were assessed. Results: The pH of syrups were above critical pH for demineralization of the tooth but tiratable acidity and buffering capacity differed. ANOVA test indicated that the reduction in mean micro hardness was maximum in Group D (Conventional Analgesic syrup and least in Group A (Sugarfree cough syrup on 7 th and 14 th day. On intergroup comparison there was no difference (P > 0.05 in micro hardness between Group B (Conventional Cough syrup and Group C (Conventional Antibiotic. However, highly significant (P < 0.01 difference between the either pair of Group B with Group D, and Group C with Group D on 14 th day. The percentage reduction in micro hardness on 14 th day was maximum for Group D (24.4 ± 2.2 and minimum for Group A (14.0 ± 1.3 which was statistically significant (P < 0.01. Conclusion: Sugar free pediatric medicines can be effective in reducing dental erosion and efforts should be made to incorporate sugar substitutes in formulation of pediatric medicines.

Effect of Quenching Rate on Microstructure and Hardness of Al-Zn-Mg-Cu-Cr Alloy Extruded Bar

Directory of Open Access Journals (Sweden)

HAN Su-qi

2017-04-01

Full Text Available The effect of quenching rate on microstructure and hardness of Al-Zn-Mg-Cu-Cr alloy extruded bar was studied by hardness test, scanning electron microscopy and transmission electron microscopy. The results show that at quenching rate below 100℃/s, during the cooling process, the hardness begins to fall significantly; and it decreases by 43% at the quenching rate of 2℃/s. At quenching rate below 100℃/s, the number and size of equilibrium η phase heterogeneously nucleated at(subgrain boundaries and on dispersoids inside grains increase obviously with the decrease of quenching rate, leading to greatly reduced age-hardening response. At the same quenching rate, the equilibrium η phase inside grains is larger than that at grain boundaries. In the range of the studied quenching rates, a quantitative relationship between hardness and equilibrium η phase area fraction has been established.

Wave packet autocorrelation functions for quantum hard-disk and hard-sphere billiards in the high-energy, diffraction regime.

Science.gov (United States)

Goussev, Arseni; Dorfman, J R

2006-07-01

We consider the time evolution of a wave packet representing a quantum particle moving in a geometrically open billiard that consists of a number of fixed hard-disk or hard-sphere scatterers. Using the technique of multiple collision expansions we provide a first-principle analytical calculation of the time-dependent autocorrelation function for the wave packet in the high-energy diffraction regime, in which the particle's de Broglie wavelength, while being small compared to the size of the scatterers, is large enough to prevent the formation of geometric shadow over distances of the order of the particle's free flight path. The hard-disk or hard-sphere scattering system must be sufficiently dilute in order for this high-energy diffraction regime to be achievable. Apart from the overall exponential decay, the autocorrelation function exhibits a generally complicated sequence of relatively strong peaks corresponding to partial revivals of the wave packet. Both the exponential decay (or escape) rate and the revival peak structure are predominantly determined by the underlying classical dynamics. A relation between the escape rate, and the Lyapunov exponents and Kolmogorov-Sinai entropy of the counterpart classical system, previously known for hard-disk billiards, is strengthened by generalization to three spatial dimensions. The results of the quantum mechanical calculation of the time-dependent autocorrelation function agree with predictions of the semiclassical periodic orbit theory.

Geomechanics in hard rock mining-Lessons from two case histories

International Nuclear Information System (INIS)

Heuze, F.E.

1982-01-01

This paper summarizes the geomechanics programs conducted in two hard rock underground mining operations in the Western United States, between 1966 and 1981. The two projects were directed towards understanding the behavior of the rock masses, at the scale of the caverns. To this end, the emphasis was put on large scale field measurements, complemented by limited laboratory testing. The results of these observations were used to build realistic finite element models of the underground chambers. In the marble mine, at Crestmore, California, the models were applied to the structural optimization of the room-and-pillar pattern. In the granite mining, at Climax, Nevada Test Site, the models explained some unusual stress changes observed during excavation. Based on the large number of geomechanical techniques employed, specific conclusions and recommendations are offered regarding the quality, applicability, and usefulness of the various methods. The two case histories clearly indicate that numerical models are extremely useful for a detailed understanding of the structural behavior of mine openings. To be realistic, these models must be based first and foremost on large scale field observations. The lessons learned on these two projects also are directly applicable to the design and analysis of nuclear waste repositories in hard rocks such as basalt, granite, and welded tuff

Water Hardness Level and ItAND#8217;s Health Effects

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Necmettin Kocak

2011-04-01

Full Text Available Water hardness is a term used to define the number of ions contained in the water, especially quantity sulphate, carbonate salts of calcium and magnesium. This characteristis of water is a important quality in it’s use as drinking water, industrial water and service water. The temporary hardness level of water cames from bicarbonate salts of calcium and magnesium whereas chloride, sulphate, nitrate, phosphate, silicate salts of calcium and magnesium. In order to indicate the hardness level of water samples French Hardness Level is used in our country. There is a larger amounth of calcium and magnesium salts in hard water samples. These minerals have very important functions in the human body. In this study, the importance of hard water in terms of human health has been assessed under light of current information. The studies about the preventive role of hard water in cardiovascular diseases, cerebrovascular diseases, stroke and many types of cancer areviewed. These studies Express that higher levels of calcium and magnesium hard water provide a higher reduction in these disease. Water, which must be consumed as 2 liters per dayis very important for human life. Hard water contains a lot of the minerals that must be taker daily, especially calcium and magnesium. It’s advised that water for consumption to have medium hardness. The hardness level of water is an aesthetic quality. Thus, in populations having a taste for soft water, the effort of individuals to softer the network water provided by municipalities using different equipments, in addition to their preference of soft water in plastic or glass bottles for consumption could imply lack of benefit of hard water for population health and also bring out some risks in terms of water hygiene. [TAF Prev Med Bull 2011; 10(2.000: 187-192

Transport coefficients and mechanical response in hard-disk colloidal suspensions

Science.gov (United States)

Zhang, Bo-Kai; Li, Jian; Chen, Kang; Tian, Wen-De; Ma, Yu-Qiang

2016-11-01

We investigate the transport properties and mechanical response of glassy hard disks using nonlinear Langevin equation theory. We derive expressions for the elastic shear modulus and viscosity in two dimensions on the basis of thermal-activated barrier-hopping dynamics and mechanically accelerated motion. Dense hard disks exhibit phenomena such as softening elasticity, shear-thinning of viscosity, and yielding upon deformation, which are qualitatively similar to dense hard-sphere colloidal suspensions in three dimensions. These phenomena can be ascribed to stress-induced “landscape tilting”. Quantitative comparisons of these phenomena between hard disks and hard spheres are presented. Interestingly, we find that the density dependence of yield stress in hard disks is much more significant than in hard spheres. Our work provides a foundation for further generalizing the nonlinear Langevin equation theory to address slow dynamics and rheological behavior in binary or polydisperse mixtures of hard or soft disks. Project supported by the National Basic Research Program of China (Grant No. 2012CB821500) and the National Natural Science Foundation of China (Grant Nos. 21374073 and, 21574096).

Driven self-assembly of hard nanoplates on soft elastic shells

International Nuclear Information System (INIS)

Zhang Yao-Yang; Hua Yun-Feng; Deng Zhen-Yu

2015-01-01

The driven self-assembly behaviors of hard nanoplates on soft elastic shells are investigated by using molecular dynamics (MD) simulation method, and the driven self-assembly structures of adsorbed hard nanoplates depend on the shape of hard nanoplates and the bending energy of soft elastic shells. Three main structures for adsorbed hard nanoplates, including the ordered aggregation structures of hard nanoplates for elastic shells with a moderate bending energy, the collapsed structures for elastic shells with a low bending energy, and the disordered aggregation structures for hard shells, are observed. The self-assembly process of adsorbed hard nanoplates is driven by the surface tension of the elastic shell, and the shape of driven self-assembly structures is determined on the basis of the minimization of the second moment of mass distribution. Meanwhile, the deformations of elastic shells can be controlled by the number of adsorbed rods as well as the length of adsorbed rods. This investigation can help us understand the complexity of the driven self-assembly of hard nanoplates on elastic shells. (paper)

Effective depth-of-penetration range due to hardness variation for different lots of nominally identical target material

Directory of Open Access Journals (Sweden)

Patrick Frueh

2016-04-01

A linear regression analysis of penetration vs. hardness shows that a target hardness increase within the given range of 280–330 BHN may result in a reduction of penetration depth of about 5.8 mm at constant velocity. This is equal to a change of −12% at an impact velocity of 1250 m/s. A multiple linear regression analysis included also the influence of yaw angle and impact velocity. It shows that small yaw angles and slight variations of impact velocities provide a smaller variation of the semi-infinite penetration depths than a variation of target hardness within a typical specification span of 50 BHN. For such a span a change in penetration of approximately −4.8 mm due to hardness variation is found, whereas 1° of yaw angle or −10 m/s of velocity variation gives a change of about −1.0 mm respectively −0.9 mm. For the given example, the overwhelming part of the variation is to be attributed to hardness effects – 4.8 mm out of 5.8 mm (83%. For nominally identical target material the target hardness thus influences the ballistic test results more severely than the typical scatter in impact conditions.

Hard template synthesis of metal nanowires

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Go eKawamura

2014-11-01

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

Broad-band hard X-ray reflectors

DEFF Research Database (Denmark)

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

1997-01-01

Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity...... of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of the supermirror is superior to that of gold, extending the band of reflection at least a factor of 2.8 beyond...... that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted....

Corrosion performance of some titanium-based hard coatings

International Nuclear Information System (INIS)

Matthes, B.; Broszeit, E.; Aromaa, J.; Ronkainen, H.; Hannula, S.P.; Leyland, A.; Matthews, A.

1991-01-01

Tools and machine parts which could benefit from wear-resistant titanium-based hard films are often subject to corrosive environments. Physically vapour-deposited coatings frequently exhibit porosity and even small defects, which can cause rapid local corrosion of the substrate material; there is therefore a requirement for dense and chemically inert coatings. This paper presents corrosion data for titanium-based hard coatings such as TiN, (Ti, Al)N, Ti(B, N) and TiB 2 and also for multilayered structures where additional aluminium-based insulating surface layers (AlN and Al 2 O 3 ) were deposited. The corrosion resistance and porosity of the films were analysed by electrochemical techniques. The degree of metallic bonding can play a significant role in influencing the corrosion resistance of refractory transition-metal-based ceramic coatings. Here we demonstrate that, under potentiodynamic corrosion test conditions, resistance to corrosive attack was relatively poor for TiB 2 , better for (Ti, Al)N and Ti(B, N) and best for TiN. It is also shown that applying the additional protective aluminium-based insulating surface layers on the coating can further improve corrosion resistance. (orig.)

Sputter deposition and characterisation of hard wear-resistant Ti/TiN multilayers

Energy Technology Data Exchange (ETDEWEB)

Simmonds, M.C.; Swygenhoven, H. van [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

Multilayered Ti/TiN thin films have been synthesized by magnetron sputter deposition. Alternating layers of Ti and TiN with layer thickness in the 5-50 nm range are sequentially deposited. The structure of the films have been characterised by atomic force microscopy (AFM), X-ray diffraction and reflection and Auger depth profiling. The mechanical properties have been investigated using pin-on-disc wear rate testing, nanoindentation determination of hardness and micro scratch testing. (author) 1 fig., 3 refs.

Rock-hard coatings

NARCIS (Netherlands)

Muller, M.

2007-01-01

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

Hazards of the 'hard cash': hypersensitivity pneumonitis.

Science.gov (United States)

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.

Factorization and non-factorization in diffractive hard scattering

International Nuclear Information System (INIS)

Berera, Arjun

1997-01-01

Factorization, in the sense defined for inclusive hard scattering, is discussed for diffractive hard scattering. A factorization theorem similar to its inclusive counterpart is presented for diffractive DIS. For hadron-hadron diffractive hard scattering, in contrast to its inclusive counterpart, the expected breakdown of factorization is discussed. Cross section estimates are given from a simple field theory model for non-factorizing double-pomeron-exchange (DPE) dijet production with and without account for Sudakov suppression

Hard template synthesis of metal nanowires

OpenAIRE

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 o...

Radiation-hard Silicon Photonics for Future High Energy Physics Experiments

CERN Document Server

AUTHOR|(CDS)2089774; Troska, Jan

Collisions of proton beams in the Large Hadron Collider at CERN produce very high radiation levels in the innermost parts of the particle detectors and enormous amounts of measurement data. Thousands of radiation-hard optical links based on directly-modulated laser diodes are thus installed in the particle detectors to transmit the measurement data to the processing electronics. The radiation levels in the innermost regions of future particle detectors will be much higher than they are now. Alternative solutions to laser-based radiation-hard optical links have to be found since the performance of laser diodes decreases beyond the operation margin of the system when irradiated to sufficiently high radiation levels. Silicon Photonics (SiPh) is currently being investigated as a promising alternative technology. First tests have indeed shown that SiPh Mach-Zehnder modulators (MZMs) are relatively insensitive to a high neutron fluence. However, they showed a strong degradation when exposed to ionizing radiation. ...

ERRATUM: Work smart, wear your hard hat

CERN Multimedia

2003-01-01

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

Flour quality and kernel hardness connection in winter wheat

Directory of Open Access Journals (Sweden)

Szabó B. P.

2016-12-01

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

Hardness of Clustering

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Hardness of Clustering. Both k-means and k-medians intractable (when n and d are both inputs even for k =2). The best known deterministic algorithms. are based on Voronoi partitioning that. takes about time. Need for approximation – “close” to optimal.

Evaluation of hard fossil fuel

International Nuclear Information System (INIS)

Zivkovic, S.; Nuic, J.

1999-01-01

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

Calorimeter triggers for hard collisions

International Nuclear Information System (INIS)

Landshoff, P.V.; Polkinghorne, J.C.

1978-01-01

We discuss the use of a forward calorimeter to trigger on hard hadron-hadron collisions. We give a derivation in the covariant parton model of the Ochs-Stodolsky scaling law for single-hard-scattering processes, and investigate the conditions when instead a multiple- scattering mechanism might dominate. With a proton beam, this mechanism results in six transverse jets, with a total average multiplicity about twice that seen in ordinary events. We estimate that its cross section is likely to be experimentally accessible at avalues of the beam energy in the region of 100 GeV/c

Hardness of ion implanted ceramics

International Nuclear Information System (INIS)

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

1985-01-01

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

Analysis of hard coal quality for narrow size fraction under 20 mm

Science.gov (United States)

Niedoba, Tomasz; Pięta, Paulina

2018-01-01

The paper presents the results of an analysis of hard coal quality diversion in narrow size fraction by using taxonomic methods. Raw material samples were collected in selected mines of Upper Silesian Industrial Region and they were classified according to the Polish classification as types 31, 34.2 and 35. Then, each size fraction was characterized in terms of the following properties: density, ash content, calorific content, volatile content, total sulfur content and analytical moisture. As a result of the analysis it can be stated that the best quality in the entire range of the tested size fractions was the 34.2 coking coal type. At the same time, in terms of price parameters, high quality of raw material characterised the following size fractions: 0-6.3 mm of 31 energetic coal type and 0-3.15 mm of 35 coking coal type. The methods of grouping (Ward's method) and agglomeration (k-means method) have shown that the size fraction below 10 mm was characterized by higher quality in all the analyzed hard coal types. However, the selected taxonomic methods do not make it possible to identify individual size fraction or hard coal types based on chosen parameters.

Association of systemic risk factors with the severity of retinal hard exudates in a north Indian population with type 2 diabetes

Directory of Open Access Journals (Sweden)

Sachdev N

2010-01-01

Full Text Available Background: The various risk factors for diabetic retinopathy and its spectrum are still poorly understood in the Indian population. Aims: To study the association of various systemic risk factors with retinal hard exudates in type 2 diabetic north Indian patients and to measure the incidence of dyslipidemia in them. Settings and Design: A tertiary-hospital-based cross-sectional study. Materials and Methods: An observational case-study which included 180 type 2 diabetic patients (180 eyes of nonproliferative diabetic retinopathy (NPDR with clinically significant macular edema (CSME. In these patients the retinal hard exudates were graded on a central 500 fundus picture using modified Airlie House classification and divided into three groups of absent or minimal hard exudates (Group 1, hard exudates present (Group 2 and prominent hard exudates (Group 3. Their association with various risk factors, namely the age of onset of diabetes and its duration, gender, insulin therapy, and various systemic parameters like hypertension, blood hemoglobin, glycosylated hemoglobin, serum (s. creatinine levels, 24-h proteinuria and complete lipid profile including total s. cholesterol, low-density lipoprotein cholesterol (LDL, high-density lipoprotein cholesterol (HDL, very low-density lipoprotein cholesterol (VLDL and s. triglyceride (TG was studied. The incidence of dyslipidemia was also calculated among these groups of patients. Statistical Analysis: ANOVA test, linear regression analysis and Spearman′s correlation test. Results: On univariate analysis, the retinal hard exudates were significantly associated with s. creatinine (P=0.016, systolic blood pressure (P=0.014, s. cholesterol (P < 0.001, s. LDL (P=0.008 and s. TG (P=0.013 levels. While on linear regression analysis, s. cholesterol (P < 0.001 and s. LDL cholesterol (P=0.028 were found to be independent risk factors affecting the density of retinal hard exudates. On Spearman′s correlation test, the

Assessment of the hardness of different orthodontic wires and brackets produced by metal injection molding and conventional methods.

Science.gov (United States)

Alavi, Shiva; Kachuie, Marzie

2017-01-01

This study was conducted to assess the hardness of orthodontic brackets produced by metal injection molding (MIM) and conventional methods and different orthodontic wires (stainless steel, nickel-titanium [Ni-Ti], and beta-titanium alloys) for better clinical results. A total of 15 specimens from each brand of orthodontic brackets and wires were examined. The brackets (Elite Opti-Mim which is produced by MIM process and Ultratrimm which is produced by conventional brazing method) and the wires (stainless steel, Ni-Ti, and beta-titanium) were embedded in epoxy resin, followed by grinding, polishing, and coating. Then, X-ray energy dispersive spectroscopy (EDS) microanalysis was applied to assess their elemental composition. The same specimen surfaces were repolished and used for Vickers microhardness assessment. Hardness was statistically analyzed with Kruskal-Wallis test, followed by Mann-Whitney test at the 0.05 level of significance. The X-ray EDS analysis revealed different ferrous or co-based alloys in each bracket. The maximum mean hardness values of the wires were achieved for stainless steel (SS) (529.85 Vickers hardness [VHN]) versus the minimum values for beta-titanium (334.65 VHN). Among the brackets, Elite Opti-Mim exhibited significantly higher VHN values (262.66 VHN) compared to Ultratrimm (206.59 VHN). VHN values of wire alloys were significantly higher than those of the brackets. MIM orthodontic brackets exhibited hardness values much lower than those of SS orthodontic archwires and were more compatible with NiTi and beta-titanium archwires. A wide range of microhardness values has been reported for conventional orthodontic brackets and it should be considered that the manufacturing method might be only one of the factors affecting the mechanical properties of orthodontic brackets including hardness.

Utility of the ImPACT test with deaf adolescents.

Science.gov (United States)

Reesman, Jennifer; Pineda, Jill; Carver, Jenny; Brice, Patrick J; Zabel, T Andrew; Schatz, Philip

2016-02-01

The goals of the study included empirical examination of the utility of the Immediate and Post-Concussion Assessment and Cognitive Testing (ImPACT) test with adolescents who are deaf or hard-of-hearing and to investigate patterns of performance at baseline that may arise in the assessment of this population. Baseline assessment of student-athletes has been conducted on a widespread scale with focus on performance of typically developing student-athletes and some clinical groups, though to date no studies have examined adolescents who are deaf or hard-of-hearing. Retrospective and de-identified ImPACT baseline test used with deaf and hard-of-hearing high-school student-athletes (N = 143; 66% male, mean age = 16.11) was examined. Review indicated significant differences in some composite scores between the deaf and hard-of-hearing group and hearing normative comparisons. A possible marker of task misunderstanding was identified to occur more frequently within the deaf and hard-of-hearing sample (13% in deaf sample vs. .31% in hearing sample). Results may provide support for the consideration and use of additional measures to ensure comprehension of task demands when considering this tool for use with deaf and hard-of-hearing adolescents.

Hardness in high temperature of steels ABNT H11 and ABNT H11 modified with niobium

International Nuclear Information System (INIS)

Goncalves, R.A.

1984-01-01

A method to measure the hardness of metallic materials was developed. The heating was done by the Joule effect heat dissipation in the sample, that is like an electrical resistor. A diamond penetrator with a revolution paraboloid format was used, that assure a linear relation between the load applyed and the penetration deep. Hardness tests were make in the range of 25 - 600 0 C, in the steels ABNT H11 and ABNT H11 modified with niobium, with the simultaneous register of the applied force, penetration deep and temperature. (E.G.) [pt

Hot hardness studies on zircaloy 2 pressure tube along three orientations

International Nuclear Information System (INIS)

Kutty, T.R.G.; Ravi, K.; Jarvis, T.; Sengupta, A.K.; Majumdar, S.; Tewari, R.; Shrivastava, D.; Dey, G.K.

2002-01-01

Zirconium based alloys are the natural choice for both the fuel element cans and in-core structural components in water cooled nuclear reactors. In this paper, the hot hardness behaviour of zircaloy 2 pressure tubes has been examined from room temperature to 400 degC using a hot hardness tester. For the purpose of comparison, the hardness of the as cast and room temperature rolled specimens has also been carried out. For this, the samples were cut along three orientations and hardness was measured in each of these directions using Vickers diamond pyramid indenter. The variation in hardness of the pressure tube samples show that the hardness was highest along circumferential direction and least along the axial direction. The room temperature rolled samples showed highest hardness along the rolling planes. These variations in hardness could be explained in terms of development of texture during working on the material. (author)

Hard exudates segmentation based on learned initial seeds and iterative graph cut.

Science.gov (United States)

Kusakunniran, Worapan; Wu, Qiang; Ritthipravat, Panrasee; Zhang, Jian

2018-05-01

(Background and Objective): The occurrence of hard exudates is one of the early signs of diabetic retinopathy which is one of the leading causes of the blindness. Many patients with diabetic retinopathy lose their vision because of the late detection of the disease. Thus, this paper is to propose a novel method of hard exudates segmentation in retinal images in an automatic way. (Methods): The existing methods are based on either supervised or unsupervised learning techniques. In addition, the learned segmentation models may often cause miss-detection and/or fault-detection of hard exudates, due to the lack of rich characteristics, the intra-variations, and the similarity with other components in the retinal image. Thus, in this paper, the supervised learning based on the multilayer perceptron (MLP) is only used to identify initial seeds with high confidences to be hard exudates. Then, the segmentation is finalized by unsupervised learning based on the iterative graph cut (GC) using clusters of initial seeds. Also, in order to reduce color intra-variations of hard exudates in different retinal images, the color transfer (CT) is applied to normalize their color information, in the pre-processing step. (Results): The experiments and comparisons with the other existing methods are based on the two well-known datasets, e_ophtha EX and DIARETDB1. It can be seen that the proposed method outperforms the other existing methods in the literature, with the sensitivity in the pixel-level of 0.891 for the DIARETDB1 dataset and 0.564 for the e_ophtha EX dataset. The cross datasets validation where the training process is performed on one dataset and the testing process is performed on another dataset is also evaluated in this paper, in order to illustrate the robustness of the proposed method. (Conclusions): This newly proposed method integrates the supervised learning and unsupervised learning based techniques. It achieves the improved performance, when compared with the

Hard probes 2006 Asilomar

CERN Multimedia

2006-01-01

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

Effect of solute grain boundary segregation and hardness on the ductile-to-brittle transition for a Cr-Mo low-alloy steel

International Nuclear Information System (INIS)

Shen, D.-D.; Song, S.-H.; Yuan, Z.-X.; Weng, L.-Q.

2005-01-01

Combined solute grain boundary segregation and hardness effect on the ductile-to-brittle transition is examined for a P-doped 2.25Cr-1Mo steel by means of Auger electron spectroscopy (AES) in conjunction with hardness measurements, Charpy impact tests and scanning electron microscopy (SEM). During ageing at 540 deg. C after water quenching from 980 deg. C, the segregation of phosphorus, molybdenum and chromium increases and the hardness decreases with increasing ageing time. The ductile-to-brittle transition temperature (DBTT) increases with increasing phosphorus segregation and decreases with decreasing hardness. The phosphorus segregation effect is dominant until 100 h ageing and after that the hardness effect becomes dominant, making the DBTT decrease with further increasing ageing time although the segregation of phosphorus still increases strongly. The segregation of molybdenum has some effect on the DBTT decrease

Evidence of feasible hardness test on Mars using ratio of ionic/neutral emission intensities measured with laser-induced breakdown spectroscopy in low pressure CO_2 ambient gas

International Nuclear Information System (INIS)

Abdulmadjid, Syahrun Nur; Lahna, Kurnia; Idris, Nasrullah; Pardede, Marincan; Suyanto, Hery; Ramli, Muliadi; Marpaung, Alion Mangasi; Hedwig, Rinda; Lie, Zener Sukra; Kurniawan, Davy Putra; Kurniawan, Koo Hendrik; Lie, Tjung Jie; Tjia, May On; Kagawa, Kiichiro

2016-01-01

An experimental study is conducted on the possibility and viability of performing hardness measurement of the various stone and chert samples in low pressure (600 Pa) CO_2 ambient gas, a condition that is encountered in the Mars atmosphere. For this study, a nanosecond Nd-YAG laser is employed to generate plasma emission from the samples with different degrees of hardness. This technique is developed in light of the role of the shock wave in the generation of a laser-induced plasma. It was previously shown that the speed of the shock front depends on the hardness of the sample, and a positive relationship was found between the speed of the shock front and the ionization rate of the ablated atoms. Hence, the ratio of the intensity between the Mg II 279.5 nm and Mg I 285.2 nm emission lines detected from the laser-induced plasma can be used to estimate the hardness of a material. In fact, it is shown that the ratio changes linearly with respect to changes of sample hardness. The result has thus demonstrated the feasibility and viability of using LIBS for non contact hardness measurement on Mars.

The Effectiveness of Hard Martial Arts in People over Forty: An Attempted Systematic Review

Directory of Open Access Journals (Sweden)

Gaby Pons van Dijk

2014-04-01

Full Text Available The objective was to assess the effect of hard martial arts on the physical fitness components such as balance, flexibility, gait, strength, cardiorespiratory function and several mental functions in people over forty. A computerized literature search was carried out. Studies were selected when they had an experimental design, the age of the study population was >40, one of the interventions was a hard martial art, and when at least balance and cardiorespiratory functions were used as an outcome measure. We included four studies, with, in total, 112 participants, aged between 51 and 93 years. The intervention consisted of Taekwondo or Karate. Total training duration varied from 17 to 234 h. All four studies reported beneficial effects, such as improvement in balance, in reaction tests, and in duration of single leg stance. We conclude that because of serious methodological shortcomings in all four studies, currently there is suggestive, but insufficient evidence, that hard martial arts practice improves physical fitness functions in healthy people over 40. However, considering the importance of such effects, and the low costs of the intervention, the potential of beneficial health effects of age-adapted, hard martial arts training, in people over 40, warrants further study.

Stress Tests for Chest Pain: When You Need an Imaging Test -- and When You Don't

Science.gov (United States)

... Resources Adult , Geriatric Stress Tests for Chest Pain Stress Tests for Chest Pain When you need an ... pain isn’t from heart disease. A cardiac stress test makes the heart work hard so your ...

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

Directory of Open Access Journals (Sweden)

Jon Dron

2013-03-01

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

Static structure of active Brownian hard disks

Science.gov (United States)

de Macedo Biniossek, N.; Löwen, H.; Voigtmann, Th; Smallenburg, F.

2018-02-01

We explore the changes in static structure of a two-dimensional system of active Brownian particles (ABP) with hard-disk interactions, using event-driven Brownian dynamics simulations. In particular, the effect of the self-propulsion velocity and the rotational diffusivity on the orientationally-averaged fluid structure factor is discussed. Typically activity increases structural ordering and generates a structure factor peak at zero wave vector which is a precursor of motility-induced phase separation. Our results provide reference data to test future statistical theories for the fluid structure of active Brownian systems. This manuscript was submitted for the special issue of the Journal of Physics: Condensed Matter associated with the Liquid Matter Conference 2017.

Dependence of Hardness of Silicate Glasses on Composition and Thermal History

DEFF Research Database (Denmark)

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

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

IMPACT OF ROCK HARDNESS ON FRAGMENTATION BY HYDRAULIC HAMMER AND CRUSHING IN JAW CRUSHER

Directory of Open Access Journals (Sweden)

Trpimir Kujundžić

2008-12-01

Full Text Available The physical and mechanical characteristics of intact rocks depend on the way of their formation, sustained deformations and the process of wearing a specific rock has been exposed to. These characteristics have a rather high influence on the technological process of extraction and dressing of mineral raw materials. However, the mechanical characteristics of rocks due to use of explosives for their extraction in the open pit have a more significant impact. The rock blocks extracted by blasting which are larger than the opening of the primary crusher are usually fragmented by hydraulic hammer. The paper presents the results of the testing of impact of rock hardness on fragmentation of rocks by means of hydraulic hammer and during crushing in jaw crusher. The testing was carried out on the rock samples from five quarries. According to the obtained results the hardness has a considerably larger impact on the fragmentation energy by hydraulic hammer than on the crushing energy in jaw crusher.

Playing Moderately Hard to Get

Directory of Open Access Journals (Sweden)

Stephen Reysen

2013-12-01

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

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

Science.gov (United States)

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.

Obtention of high hardness multilayer systems by laser ablation

International Nuclear Information System (INIS)

Mejia T, I.S.

2007-01-01

In this thesis work the synthesis of thin films of titanium nitride (TiN), amorphous carbon nitride (CN x ) amorphous carbon (a-C) and Ti/TiN/CNx multilayers and Ti/TiN/a-C by means of the laser ablation technique, with the objective of obtaining films of high hardness is studied, as well as to produce multilayer coatings with superior properties to the individual layers. The effect that has the laser fluence used for ablationing the targets in the structure and mechanical properties of the films deposited of TiN was investigated. It was found that the hardness is increased in lineal way approximately with the fluence increment up to 19 J/cm 2 . Thin films of a-C with hardness of the order of 12 GPa. likewise CN x films with high hardness (18.4 GPa) were obtained. The hardness of the deposited films was analyzed and it was related with its microstructure and deposit conditions. It was concluded that the Ti/TiN/CNx and Ti/TiN/a-C systems presented bigger hardness that of its individual components. (Author)

Sampling from a polytope and hard-disk Monte Carlo

International Nuclear Information System (INIS)

Kapfer, Sebastian C; Krauth, Werner

2013-01-01

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

The over-the-limb hard X-ray events

Science.gov (United States)

Hudson, H. S.

Over-the-limb hard X-ray events offer a uniquely direct view of the hard X-ray emission from the solar corona during a major flare. Limb occultation at angles greater than about 10 deg (an arbitrary definition of this class of events) excludes any confusion with brighter chromospheric sources. Published observations of seven over-the-limb events, beginning with the prototype flare of March 30, 1969, are reviewed. The hard X-ray spectra appear to fall into two classes: hard events, with power-law index of about 2.0; and soft events, with power-law index about 5.4. This tendency towards bimodality is only significant at the 90-percent confidence level due to the smallness of the number of events observed to date. If borne out by future data, the bimodality would suggest the existence of two different acceleration mechanisms.

Constraint satisfaction problems with isolated solutions are hard

International Nuclear Information System (INIS)

Zdeborová, Lenka; Mézard, Marc

2008-01-01

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

A study on friability, hardness and fiber content analysis of fiber enriched milk tablet

Science.gov (United States)

Suzihaque, M. U. H.; Irfan, M. H.; Ibrahim, U. K.

2017-06-01

This study was performed to analyze the friability, hardness and fiber content of fiber enriched milk tablet derived from five different local fiber sources such as carrot, spinach, dragon fruit, mango and watermelon. Cow milk was mixed to complement with the tablet as a protein source. The powder were spray dried at 100°C, 120°C and 140°C and freeze dried at -60°C. The mixture of fruits and milk were made into equal ratio with the addition of 15 maltodextrin as a carrier. Tablets formed were used for friability and hardness test while dried powder were used for fiber content analysis. Dragon fruit tablet dried at 140°C have the highest friability with 11. 42 of weight loss. The second highest friability was spinach tablet dried at 100°C and 120°C drying temp erature with 9.30 and 9.28 respectively. The lowest friability was exhibited by carrot, mango and watermelon tablet at 100°C and dragon fruit at 120°C while carrot and spinach at 140°C. In contras t, none of the freeze dried tablets showed any weight loss hence they are not friable. For hardness test, all of the freeze dried showed to have higher tensile strength than spray dried, where carrot showed to be the highest at 2.27 Newton and the lowest were spray dried mango at 0.16 Newton. In fiber content analysis, freeze dried mango have the highest fiber content followed by freeze dried carrot and 140°C s pray dried carrot. It can be concluded that the higher the spray dry temperature, the more friable is the tablet. While, high friability leads to lower hardness of tablets. In terms of fiber content, the higher the spray dry temperature, the lower the fiber content found.

Effect of insertion method on knoop hardness of high viscous glass ionomer cements

NARCIS (Netherlands)

Raggio, D.P.; Bonifácio, C.C.; Bönecker, M.; Imparato, J.C.P.; de Gee, A.J.; van Amerongen, W.E.

2010-01-01

The aim of this study was to assess the Knoop hardness of three high viscous glass ionomer cements: G1 - Ketac Molar; G2 - Ketac Molar Easymix (3M ESPE) and G3 - Magic Glass ART (Vigodent). As a parallel goal, three different methods for insertion of Ketac Molar Easymix were tested: G4 -

Excavation Technology for Hard Rock - Problems and Prospects

International Nuclear Information System (INIS)

Gillani, S.T.A.; Butt, N.

2009-01-01

Civil engineering projects have greatly benefited from the mechanical excavation of hard rock technology. Mining industry, on the other hand, is still searching for major breakthroughs to mechanize and then automate the winning of ore and drivage of access tunnels in its metalliferous sector. The aim of this study is to extend the scope of drag bits for road headers in hard rock cutting. Various factors that can impose limitations on the potential applications of drag bits in hard rock mining are investigated and discussed along with alternative technology options. (author)

Performance ratio hardness characteristics polystyrene-metal composite materials

International Nuclear Information System (INIS)

Klepikov, V.F.; Prokhorenko, E.M.; Lytvynenko, V.V.; Zakharchenko, A.A.; Hazhmuradov, M.A.

2015-01-01

The methods of measuring the hardness of layered polystyrene-metallic composite materials. It is proposed to use powder-like tungsten and powder-like steel as radiation-protective layer. A measurement of the hardness of composites of different composition, and given its dependence on the particle size and their form. The possibility of increasing the hardness of the composites reinforced with metallic additives. Radiation-protective characteristics were calculated for the studied species of composite materials. Influence of the quantitative composition of the metal components is studied on the change of the absorbed dose of gamma radiation

3D Bioprinting Technologies for Hard Tissue and Organ Engineering

Science.gov (United States)

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

2016-01-01

Hard tissues and organs, including the bones, teeth and cartilage, are the most extensively exploited and rapidly developed areas in regenerative medicine field. One prominent character of hard tissues and organs is that their extracellular matrices mineralize to withstand weight and pressure. Over the last two decades, a wide variety of 3D printing technologies have been adapted to hard tissue and organ engineering. These 3D printing technologies have been defined as 3D bioprinting. Especially for hard organ regeneration, a series of new theories, strategies and protocols have been proposed. Some of the technologies have been applied in medical therapies with some successes. Each of the technologies has pros and cons in hard tissue and organ engineering. In this review, we summarize the advantages and disadvantages of the historical available innovative 3D bioprinting technologies for used as special tools for hard tissue and organ engineering. PMID:28773924

3D Bioprinting Technologies for Hard Tissue and Organ Engineering

Directory of Open Access Journals (Sweden)

Xiaohong Wang

2016-09-01

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

3D Bioprinting Technologies for Hard Tissue and Organ Engineering.

Science.gov (United States)

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

2016-09-27

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

Unified Research on Network-Based Hard/Soft Information Fusion

Science.gov (United States)

2016-02-02

3.2.1 Hard +Soft Data Association Data gathered during various Counterinsurgency (or COIN) operations is in different formats . For example, the...characteristic, observation time, and related data. Figure 45: Sample snapshot frame from hard sensor data TML formats were developed and...160 Figure 54: Penn State components of overall hard and soft fusion process Summary of Year 1 Accomplishments • Team formation • Initial

Tribological performance of hard carbon coatings on 440C bearing steel

Energy Technology Data Exchange (ETDEWEB)

Kustas, F M; Misra, M S; Shepard, D F; Froechtenigt, J F [Martin Marietta Astronautics Group, Denver, CO (United States)

1991-11-01

Hard carbon coatings such as amorphous carbon, diamond and diamond-like carbon have received considerable attention for tribological applications owing to their high hardness, high modulus and desirable surface properties. Unfortunately, most of the deposition techniques induce high substrate temperatures that would temper traditional bearing steels and reduce the substrate load-carrying capability. Therefore, to effectively use these desirable coatings, a lower temperature deposition technique is required. Ion beam deposition can provide essentially ambient temperature conditions, accurate control of process parameters and good coating-substrate adhesion. To use these attributes, a test program was initiated to deposit mass-analyzed, high purity C{sup +} and CH{sub 4}{sup +} ions on molybdenum and 440C bearing steel for subsequent characterization by Raman spectroscopy and friction-wear tests. Results for a coating deposited from a carbon monoxide source showed an amorphous carbon-microcrystalline graphtie structure which exhibited very high microhardness and a three fold reduction in coefficient of friction for unlubricated tests compared to untreated 440C steel. In addition, incrementally increasing the applied load (by up to a factor of 5) resulted in progressively lower coefficients of friction, which conforms to solid lubrication theory. End-of-travel wear debris and some limited coating delamination were observed within thinner areas of the coating. Therefore an amorphous carbon-graphite coating applied to 440C steel at ambient temperature exhibits solid lubricating film characteristics with high load-carrying capability. (orig.).

Hard scattering and gauge/string duality

International Nuclear Information System (INIS)

Polchinski, Joseph; Strassler, Matthew J.

2002-01-01

We consider high-energy fixed-angle scattering of glueballs in confining gauge theories that have supergravity duals. Although the effective description is in terms of the scattering of strings, we find that the amplitudes are hard (power law). This is a consequence of the warped geometry of the dual theory, which has the effect that in an inertial frame the string process is never in the soft regime. At small angle we find hard and Regge behaviors in different kinematic regions

Radiation hardness of undoped BGO crystals

International Nuclear Information System (INIS)

Sahu, S.K.; Peng, K.C.; Huang, H.C.; Wang, C.H.; Chang, Y.H.; Hou, W.S.; Ueno, K.; Chou, F.I.; Wei, Y.Y.

1997-01-01

We measured the radiation hardness of undoped BGO crystals from two different manufacturers. Such crystals are proposed to be used in a small-angle calorimeter of the BELLE detector of the KEK B-factory. Transparency and scintillation light output of the crystals were monitored to see the effect of radiation damage. The crystals show considerable radiation hardness up to 10.2 Mrad equivalent dose, which is much higher than the maximum expected dosage of 500 krad per year of running at BELLE. (orig.)

Diffusion corrections to the hard pomeron

CERN Document Server

Ciafaloni, Marcello; Müller, A H; Ciafaloni, Marcello; Taiuti, Martina

2001-01-01

The high-energy behaviour of two-scale hard processes is investigated in the framework of small-x models with running coupling, having the Airy diffusion model as prototype. We show that, in some intermediate high-energy regime, the perturbative hard Pomeron exponent determines the energy dependence, and we prove that diffusion corrections have the form hinted at before in particular cases. We also discuss the breakdown of such regime at very large energies, and the onset of the non-perturbative Pomeron behaviour.

Establishment of Wear Resistant HVOF Coatings for 50CrMo4 Chromium Molybdenum Alloy Steel as an Alternative for Hard Chrome Plating

Science.gov (United States)

Karuppasamy, S.; Sivan, V.; Natarajan, S.; Kumaresh Babu, S. P.; Duraiselvam, M.; Dhanuskodi, R.

2018-05-01

High cost imported components of seamless steel tube manufacturing plants wear frequently and need replacement to ensure the quality of the product. Hard chrome plating, which is time consuming and hazardous, is conventionally used to restore the original dimension of the worn-out surface of the machine components. High Velocity Oxy-Fuel (HVOF) thermal spray coatings with NiCrBSi super alloy powder and Cr3C2 NiCr75/25 alloy powder applied on a 50CrMo4 (DIN-1.7228) chromium molybdenum alloy steel, the material of the wear prone machine component, were evaluated for use as an alternative for hard chrome plating in this present work. The coating characteristics are evaluated using abrasive wear test, sliding wear test and microscopic analysis, hardness test, etc. The study results revealed that the HVOF based NiCrBSi and Cr3C2NiCr75/25 coatings have hardness in the range of 800-900 HV0.3, sliding wear rate in the range of 50-60 µm and surface finish around 5 microns. Cr3C2 NiCr75/25 coating is observed to be a better option out of the two coatings evaluated for the selected application.

Particle production at large transverse momentum and hard collision models

International Nuclear Information System (INIS)

Ranft, G.; Ranft, J.

1977-04-01

The majority of the presently available experimental data is consistent with hard scattering models. Therefore the hard scattering model seems to be well established. There is good evidence for jets in large transverse momentum reactions as predicted by these models. The overall picture is however not yet well enough understood. We mention only the empirical hard scattering cross section introduced in most of the models, the lack of a deep theoretical understanding of the interplay between quark confinement and jet production, and the fact that we are not yet able to discriminate conclusively between the many proposed hard scattering models. The status of different hard collision models discussed in this paper is summarized. (author)

Application of pulsed laser for evaluation and optimization of SEU-Hard Designs

International Nuclear Information System (INIS)

McMorrow, D.; Melinger, J.S.; Buchner, St.; Scott, T.; Brown, R.D.

1999-01-01

Pulsed laser SEU tests are used to pinpoint and characterize sensitive nodes of CMOS circuits and to provide feedback relevant to the development and optimization of radiation-hard designs. The present study reveals several examples of the quantitative utility of the laser system. The most direct approach to obtaining quantitative thresholds from laser SEU tests involved a calibration of the measured laser upset thresholds against heavy ion results. This procedure requires only a correlation between the laser and heavy ion measurements. This study shows that this correlation exists and is particularly strong and that the calibration factor is identical to that determined in previous studies. The laser SEU threshold energy corresponds to the most sensitive node located with the laser probe. The ion-equivalent laser LET is calculated using the calibration factor noted above. The measured heavy ion threshold is given as a range since heavy-ion upset measurements are discrete: the upper value gives the lowest LET ion to induce an upset; the lower value gives the next lower LET investigated. Laser SEU measurements often can be used directly for hardness assurance or diagnosis studies. (A.C.)

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

Science.gov (United States)

Song, H. Rosi

2009-01-01

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

Glass transition temperature of hard chairside reline materials after post-polymerisation treatments.

Science.gov (United States)

Urban, Vanessa M; Machado, Ana L; Alves, Marinês O; Maciel, Adeilton P; Vergani, Carlos E; Leite, Edson R

2010-09-01

This study evaluated the effect of post-polymerisation treatments on the glass transition temperature (T(g)) of five hard chairside reline materials (Duraliner II-D, Kooliner-K, New Truliner-N, Ufi Gel hard-U and Tokuso Rebase Fast-T). Specimens (10 x 10 x 1 mm) were made following the manufacturers' instructions and divided into three groups (n = 5). Control group specimens were left untreated. Specimens from the microwave group were irradiated with pre-determined power/time combinations, and specimens from the water-bath group were immersed in hot water at 55 degrees C for 10 min. Glass transition ( degrees C) was performed by differential scanning calorimetry. Data were analysed using anova, followed by post hoc Tukey's test (alpha = 0.05). Both post-polymerisation treatments promoted a significant (p glass transition of material Kooliner, with the effect being more pronounced for microwave irradiation.

Extraordinarily soft, medium-hard and hard Indian wheat varieties: Composition, protein profile, dough and baking properties.

Science.gov (United States)

Katyal, Mehak; Singh, Narpinder; Virdi, Amardeep Singh; Kaur, Amritpal; Chopra, Nidhi; Ahlawat, Arvind Kumar; Singh, Anju Mahendru

2017-10-01

Hard wheat (HW), medium-hard wheat (MHW) and extraordinarily soft wheat (Ex-SW) varieties with grain hardness index (GHI) of 83 to 95, 72 to 80, 17 to 29 were evaluated for pasting, protein molecular weight (MW) distribution, dough rheology and baking properties. Flours from varieties with higher GHI had more protein content, ash content and paste viscosities. Ex-SW had more glutenins proportion as compared to HW and MHW. Flours from Ex-SW varieties showed lower NaSRC, WA and mixographic parameters as compared to HW and MHW. Dough from flours milled from Ex-SW had higher Intermolecular-β-sheets (IM-β-sheets) than those from MHW and HW. Muffins volume increased with decrease in GHI, Ex-SW varieties had more muffin volume and less air space. The accumulation of polypeptides (PPs) varied significantly in different varieties. Ex-SW variety (QBP12-10) showed accumulation of 98, 90, 81 and 79kDa PPs, which was unique and was different from other varieties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rock-hard coatings

OpenAIRE

Muller, M.

2007-01-01

Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has signed an agreement with a number of parties to investigate this material further.

A comparative study of the effect of soft and hard cervical collars on static postural

Directory of Open Access Journals (Sweden)

Minoo Khalkhali Zavieh

2013-01-01

Full Text Available AbstractBackground and Aim: Using cervical collars is one of the treatment methods for releaving cervical pain. The effect of limb orthotics on proprioception and postural stability has been suggested. There is not sufficient studies about the effect of cervical collars on static and dynamic stability, and the effect of soft and hard collars have not been compared with one another. The objective of this study is investigating and comparing the immediate effect of soft and hard cervical collars on static postural stability in healthy young subjects. Methods & Materials: In standing position on firm surface with closed eyes, both soft and hard collars decreased the stability and there was not any significant difference among collars. In standing positions on soft surface with closed and opened eyes, using none of the soft and hard collars did not change the stability. This quasi experimental study through repeated measure method has been conducted on 65 healthy young male and female college students. Static stability was evaluated by modified Clinical Test for Sensory Interaction and Balance (CTSIB in conditions without collar and by soft and hard cervical collars and were compared between the conditions. Results: Conclusion: Our results suggest that in static conditions, without vision, both collars decrease the stability in healthy young subjects. So considering the evaluation of stability and prevention of balance disturbance during the collar prescription seems to be necessary.

Extreme Radiation Hardness and Space Qualification of AlGaN Optoelectronic Devices

International Nuclear Information System (INIS)

Sun, Ke-Xun; MacNeil, Lawrence; Balakrishnan, Kathik; Hultgren, Eric; Goebel, John; Bilenko, Yuri; Yang, Jinwei; Sun, Wenhong; Shatalov, Max; Hu, Xuhong; Gaska, Remis

2010-01-01

Unprecedented radiation hardness and environment robustness are required in the new generation of high energy density physics (HEDP) experiments and deep space exploration. National Ignition Facility (NIF) break-even shots will have a neutron yield of 10 15 or higher. The Europa Jupiter System Mission (EJSM) mission instruments will be irradiated with a total fluence of 10 12 protons/cm 2 during the space journey. In addition, large temperature variations and mechanical shocks are expected in these applications under extreme conditions. Hefty radiation and thermal shields are required for Si and GaAs based electronics and optoelectronics devices. However, for direct illumination and imaging applications, shielding is not a viable option. It is an urgent task to search for new semiconductor technologies and to develop radiation hard and environmentally robust optoelectronic devices. We will report on our latest systematic experimental studies on radiation hardness and space qualifications of AlGaN optoelectronic devices: Deep UV Light Emitting Diodes (DUV LEDs) and solarblind UV Photodiodes (PDs). For custom designed AlGaN DUV LEDs with a central emission wavelength of 255 nm, we have demonstrated its extreme radiation hardness up to 2 x 10 12 protons/cm 2 with 63.9 MeV proton beams. We have demonstrated an operation lifetime of over 26,000 hours in a nitrogen rich environment, and 23,000 hours of operation in vacuum without significant power drop and spectral shift. The DUV LEDs with multiple packaging styles have passed stringent space qualifications with 14 g random vibrations, and 21 cycles of 100K temperature cycles. The driving voltage, current, emission spectra and optical power (V-I-P) operation characteristics exhibited no significant changes after the space environmental tests. The DUV LEDs will be used for photoelectric charge management in space flights. For custom designed AlGaN UV photodiodes with a central response wavelength of 255 nm, we have

Studying hardness, workability and minimum bending radius in selectively laser-sintered Ti–6Al–4V alloy samples

Science.gov (United States)

Galkina, N. V.; Nosova, Y. A.; Balyakin, A. V.

2018-03-01

This research is relevant as it tries to improve the mechanical and service performance of the Ti–6Al–4V titanium alloy obtained by selective laser sintering. For that purpose, sintered samples were annealed at 750 and 850°C for an hour. Sintered and annealed samples were tested for hardness, workability and microstructure. It was found that incomplete annealing of selectively laser-sintered Ti–6Al–4V samples results in an insignificant reduction in hardness and ductility. Sintered and incompletely annealed samples had a hardness of 32..33 HRC, which is lower than the value of annealed parts specified in standards. Complete annealing at temperature 850°C reduces the hardness to 25 HRC and ductility by 15...20%. Incomplete annealing lowers the ductility factor from 0.08 to 0.06. Complete annealing lowers that value to 0.025. Complete annealing probably results in the embrittlement of sintered samples, perhaps due to their oxidation and hydrogenation in the air. Optical metallography showed lateral fractures in both sintered and annealed samples, which might be the reason why they had lower hardness and ductility.

Investigation on hard coating of pivot-jewel bearing and wearing performance

International Nuclear Information System (INIS)

Han Kun; Dai Xingjian

2014-01-01

The reliability of high speed rotating machine is related to the anti-wear properties of pivot jewel bearing used in the system. To reduce its wearing process, hard coating method is used on the steel pivot. Through the wearing test on specialized facilities, its founded that the TiN coating shows better performance than DLC coating, and multi-layer TiN coating can slow down the pivot's wearing process obviously compared to other methods. (authors)

Structure, hardness and fracture features of nanostructural materials

International Nuclear Information System (INIS)

Noskova, N.I.; Korznikov, A.V.; Idrisova, S.R.

2000-01-01

A study is made into nanocrystalline metals Cu and Mo, nanocrystalline intermetallic compound Ni 3 Al produced using severe plastic deformation; nanophase alloys Fe 73.5 Cu 1 Nb 3 Si 1.35 B 9 and Pd 81 Cu 7 Si 12 produced by crystallization from amorphous state as well as nanophase materials TiN and Al 2 O 3 produced by nano powder compacting in the temperature range of 273-573 K. Methods of transmission and scanning electron microscopy, X-ray diffraction analysis, mechanical testing and microhardness measurement are applied to study structure, internal elastic stress, phase composition, hardness, strength and plastic properties, surface fracture mode of nanostructural materials [ru

Indonesia in the South China Sea Dispute: Humble-Hard Power

OpenAIRE

Robertua, Verdinand; Sinaga, Obsatar

2018-01-01

This research discussed the opportunities for Indonesia to act as humble-hard power in South China Sea dispute. Permanent Court of Arbitration’s decision in July 2016 to give South China Sea based on UNCLOS’s regulation has provoked China’s objection. This research question is on how to understand the conception of humble-hard power and the possibility for Indonesia to be humble-hard power in the South China Sea dispute? This article borrowed the concept of humble-hard power from Adam Nieves ...

Co-electrodeposition of hard Ni-W/diamond nanocomposite coatings

Science.gov (United States)

Zhang, Xinyu; Qin, Jiaqian; Das, Malay Kumar; Hao, Ruru; Zhong, Hua; Thueploy, Adisak; Limpanart, Sarintorn; Boonyongmaneerat, Yuttanant; Ma, Mingzhen; Liu, Riping

2016-02-01

Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating. Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties. In the present work, Ni-W/diamond composite coatings were prepared by sediment co-electrodeposition from Ni-W plating bath, containing suspended diamond particles. This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. The maximum hardness of Ni-W/diamond composite coatings is found to be 2249 ± 23 Hv due to the highest diamond content of 64 wt.%. The hardness could be further enhanced up to 2647 ± 25 Hv with heat treatment at 873 K for 1 h in Ar gas, which is comparable to hard chrome coatings. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings.

Tough-coated hard powders for hardmetals of novel properties

International Nuclear Information System (INIS)

Toth, R.E.; Smid, I.; Kladler, G.; Korb, G.; Sherman, A.; Ettmayer, P.

2001-01-01

The properties and performance of conventional materials and composites are constrained by solubility limits, diffusion coefficients, and compatibility of physical and chemical constituent properties in their phase equilibria. To escape these limits, ingenious ways of combining strength, toughness, and wear resistance by way of various coatings and laminations have been devised. These coated tools are systematically discarded after only about 10 % of their wear tolerance has been used. Tough-coated hard powders (TCHP), patented by EnDurAloy (USA), are hard refractory particles CVD coated with nanolayers of WC and Co. Consolidation of TCHP creates an engineered homogeneous cellular structure whose interconnected tough WC-Co 'shells' each contain a wear-resistant core (e.g., TiN). In TCHP's, the coating is throughout the tool, not only on the surface, combining the strength, heat resistance, and toughness of cemented carbides with the chemical and abrasion wear resistance of harder materials. As wear progresses, new wear-resistant material continuously replaces the working surfaces and edges of the tool until its geometry reaches its maximum limits. TCHP tools are then reusable many times. Specific coating and consolidation processes, characterization of compacts, and test comparisons with conventional materials are discussed. (author)

Hard times; Schwere Zeiten

Energy Technology Data Exchange (ETDEWEB)

Grunwald, Markus

2012-10-02

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

Effects of toothbrush hardness on in vitro wear and roughness of composite resins.

Science.gov (United States)

Kyoizumi, Hideaki; Yamada, Junji; Suzuki, Toshimitsu; Kanehira, Masafumi; Finger, Werner J; Sasaki, Keiichi

2013-11-01

To investigate and compare the effects of toothbrushes with different hardness on abrasion and surface roughness of composite resins. Toothbrushes (DENT. EX Slimhead II 33, Lion Dental Products Co. Ltd., Tokyo, Japan) marked as soft, medium and hard, were used to brush 10 beam-shaped specimens of each of three composites resins (Venus [VEN], Venus Diamond [VED] and Venus Pearl [VEP]; HeraeusKulzer) with standardized calcium carbonate slurry in a multistation testing machine (2N load, 60 Hz). After each of five cycles with 10k brushing strokes the wear depth and surface roughness of the specimens were determined. After completion of 50k strokes representative samples were inspected by SEM. Data were treated with ANOVA and regression analyses (p composite resins increased linearly with increasing number of brushing cycles (r² > 0.9). Highest wear was recorded for VEN, lowest for VED. Hard brushes produced significantly higher wear on VEN and VEP, whereas no difference in wear by toothbrush type was detected for VED. Significantly highest surface roughness was found on VED specimens (Ra > 1.5 µm), the lowest one on VEN (Ra composite resins produced by toothbrushing with dentifrice depend mainly on the type of restorative resin. Hardness grades of toothbrushes have minor effects only on abrasion and surface roughness of composite resins. No relationship was found between abrasion and surface roughness. The grade of the toothbrush used has minor effect on wear, texture and roughness of the composite resin.

Characteristics of hard X-ray double sources in impulsive solar flares

Science.gov (United States)

Sakao, T.; Kosugi, T.; Masuda, S.; Yaji, K.; Inda-Koide, M.; Makishima, K.

1996-01-01

Imaging observations of solar flare hard X-ray sources with the Hard X-ray Telescope (HXT) aboard the Yohkoh satellite have revealed that hard X-ray emissions (greater than 30 ke V) originate most frequently from double sources. The double sources are located on both sides of the magnetic neutral line, suggesting that the bulk of hard X-rays is emitted from footpoints of flaring magnetic loops. We also found that hard X-rays from the double sources are emitted simultaneously within a fraction of second and that the weaker source tends to be located in the stronger magnetic field region, showing a softer spectrum. Physcial implications on the observed characteristics of the hard X-ray double sources are discussed.

Tensile and shear bond strength of hard and soft denture relining materials to the conventional heat cured acrylic denture base resin: An In-vitro study.

Science.gov (United States)

Lau, Mayank; Amarnath, G S; Muddugangadhar, B C; Swetha, M U; Das, Kopal Anshuraj Ashok Kumar

2014-04-01

The condition of the denture bearing tissues may be adversely affected by high stress concentration during function. Chairside Denture (Hard and Soft) reliners are used to distribute forces applied to soft tissues during function. Tensile and shear bond strength has been shown to be dependent on their chemical composition. A weak bond could harbor bacteria, promote staining and delamination of the lining material. To investigate tensile and shear bond strength of 4 different commercially available denture relining materials to conventional heat cured acrylic denture base resin. 4 mm sections in the middle of 160 Acrylic cylindrical specimens (20 mm x 8 mm) were removed, packed with test materials (Mollosil, G C Reline Soft, G C Reline Hard (Kooliner) and Ufi Gel Hard and polymerized. Specimens were divided into 8 groups of 20 each. Tensile and shear bond strength to the conventional heat cured acrylic denture base resin were examined by Instron Universal Tensile Testing Machine using the equation F=N/A (F-maximum force exerted on the specimen (Newton) and A-bonding area= 50.24 mm2). One-way ANOVA was used for multiple group comparisons followed by Bonferroni Test and Hsu's MCB for multiple pairwise comparisons to asses any significant differences between the groups. The highest mean Tensile bond strength value was obtained for Ufi Gel Hard (6.49+0.08 MPa) and lowest for G C Reline Soft (0.52+0.01 MPa). The highest mean Shear bond strength value was obtained for Ufi Gel Hard (16.19+0.1 MPa) and lowest for Mollosil (0.59+0.05 MPa). The Benferroni test showed a significant difference in the mean tensile bond strength and the mean shear bond strength when the two denture soft liners were compared as well as when the two denture hard liners were compared. Hsu's MCB implied that Ufi gel hard is better than its other closest competitors. The Tensile and Shear bond strength values of denture soft reliners were significantly lower than denture hard reliners. How to cite the

Soft skills, hard skills, and individual innovativeness

DEFF Research Database (Denmark)

Hendarman, Achmad Fajar; Cantner, Uwe

2018-01-01

of Indonesian firms from different industries are used from an online survey on manager and worker perceptions related to individual innovation performance on the one hand and individual skills on the other hand. The results show that soft skills and hard skills are significantly and positively associated...... with individual level innovativeness. However, no complementarity (positive interaction effect) is found between soft skills and hard skills....

Evidence of feasible hardness test on Mars using ratio of ionic/neutral emission intensities measured with laser-induced breakdown spectroscopy in low pressure CO{sub 2} ambient gas

Energy Technology Data Exchange (ETDEWEB)

Abdulmadjid, Syahrun Nur; Lahna, Kurnia; Idris, Nasrullah [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Pardede, Marincan [Department of Electrical Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Suyanto, Hery [Department of Physics, Faculty of Mathematics and Natural Sciences, Udayana University, Kampus Bukit Jimbaran, Denpasar 80361, Bali (Indonesia); Ramli, Muliadi [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Marpaung, Alion Mangasi [Department of Physics, Faculty of Mathematics and Natural Sciences, Jakarta State University, 10 Rawamangun, Jakarta 13220 (Indonesia); Hedwig, Rinda [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Lie, Zener Sukra [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Kurniawan, Davy Putra; Kurniawan, Koo Hendrik, E-mail: kurnia18@cbn.net.id; Lie, Tjung Jie [Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Tjia, May On [Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Physics of Magnetism and Photonics Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha, Bandung 40132 (Indonesia); Kagawa, Kiichiro [Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Fukui Science Education Academy, Takagi Chuo 2 chome, Fukui 910-0804 (Japan)

2016-04-28

An experimental study is conducted on the possibility and viability of performing hardness measurement of the various stone and chert samples in low pressure (600 Pa) CO{sub 2} ambient gas, a condition that is encountered in the Mars atmosphere. For this study, a nanosecond Nd-YAG laser is employed to generate plasma emission from the samples with different degrees of hardness. This technique is developed in light of the role of the shock wave in the generation of a laser-induced plasma. It was previously shown that the speed of the shock front depends on the hardness of the sample, and a positive relationship was found between the speed of the shock front and the ionization rate of the ablated atoms. Hence, the ratio of the intensity between the Mg II 279.5 nm and Mg I 285.2 nm emission lines detected from the laser-induced plasma can be used to estimate the hardness of a material. In fact, it is shown that the ratio changes linearly with respect to changes of sample hardness. The result has thus demonstrated the feasibility and viability of using LIBS for non contact hardness measurement on Mars.

Magnetically actuated bi-directional microactuators with permalloy and Fe/Pt hard magnet

International Nuclear Information System (INIS)

Pan, C.T.; Shen, S.C.

2005-01-01

Bi-directional polyimide (PI) electromagnetic microactuator with different geometries are designed, fabricated and tested. Fabrication of the electromagnetic microactuator consists of 10 μm thick Ni/Fe (80/20) permalloy deposition on the PI diaphragm by electroplating, high aspect ratio electroplating of copper planar coil with 10 μm in thickness, bulk micromachining, and excimer laser selective ablation. They were fabricated by a novel concept avoiding the etching selectivity and residual stress problems during wafer etching. A mathematical model is created by ANSYS software to analyze the microactuator. The external magnetic field intensity (H ext ) generated by the planar coil is simulated by ANSYS software. ANSYS software is used to predict the deflection angle of the microactuator. Besides, to provide bi-directional and large deflection angle of microactuator, hard magnet Fe/Pt is deposited at a low temperature of 300 deg. C by sputtering onto the PI diaphragm to produce a perpendicular magnetic anisotropic field. This magnetic field can enhance the interaction with H ext to induce attractive and repulsive bi-directional force to provide large displacement. The results of magnetic microactuator with and without hard magnets are compared and discussed. The preliminary result reveals that the electromagnetic microactuator with hard magnet shows a greater deflection angle than that without one

Aespoe hard rock laboratory. Current research projects 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

In 1986 SKB decided to construct the Aespoe Hard Rock Laboratory (HRL) in order to provide an opportunity for research, development and demonstration in a realistic and undisturbed underground rock environment down to the depth planned for the future deep repository. The focus of current and future work is on development and testing of site characterization methods, verification of models describing the function of the natural and engineered barriers and development, testing, and demonstration of repository technology. The program has been organised so that all important steps in the development of a repository are covered, in other words the Aespoe HRL constitutes a `dress rehearsal` for the Swedish deep geological repository for spent fuel and other long-lived waste. Geoscientific investigations on Aespoe and nearby islands began in 1986. Aespoe was selected as the site for the laboratory in 1988. Construction of the facility, which reaches a depth of 460 m below the surface, began in 1990 and was completed in 1995. A major milestone had been reached in 1996 with the completion of the pre-investigation and construction phases of the Aespoe HRL. The comprehensive research conducted has permitted valuable development and verification of site characterization methods applied from the ground surface, boreholes, and underground excavations. The results of this research are summarised in the book `Aespoe Hard Rock Laboratory - 10 years of Research` published by SKB in 1996. The Operating Phase of the Aespoe HRL began in 1995 and is expected to continue for 15-20 years, that is until the first stage of the development of the Swedish deep geological repository for spent nuclear fuel is expected to be completed. A number of research projects were initiated at the start of the Operating Phase. Most of these projects have made substantial progress since then and important results have been obtained. The purpose of this brochure is to provide a brief presentation of the

Aespoe hard rock laboratory. Current research projects 1998

International Nuclear Information System (INIS)

1998-01-01

In 1986 SKB decided to construct the Aespoe Hard Rock Laboratory (HRL) in order to provide an opportunity for research, development and demonstration in a realistic and undisturbed underground rock environment down to the depth planned for the future deep repository. The focus of current and future work is on development and testing of site characterization methods, verification of models describing the function of the natural and engineered barriers and development, testing, and demonstration of repository technology. The program has been organised so that all important steps in the development of a repository are covered, in other words the Aespoe HRL constitutes a 'dress rehearsal' for the Swedish deep geological repository for spent fuel and other long-lived waste. Geoscientific investigations on Aespoe and nearby islands began in 1986. Aespoe was selected as the site for the laboratory in 1988. Construction of the facility, which reaches a depth of 460 m below the surface, began in 1990 and was completed in 1995. A major milestone had been reached in 1996 with the completion of the pre-investigation and construction phases of the Aespoe HRL. The comprehensive research conducted has permitted valuable development and verification of site characterization methods applied from the ground surface, boreholes, and underground excavations. The results of this research are summarised in the book 'Aespoe Hard Rock Laboratory - 10 years of Research' published by SKB in 1996. The Operating Phase of the Aespoe HRL began in 1995 and is expected to continue for 15-20 years, that is until the first stage of the development of the Swedish deep geological repository for spent nuclear fuel is expected to be completed. A number of research projects were initiated at the start of the Operating Phase. Most of these projects have made substantial progress since then and important results have been obtained. The purpose of this brochure is to provide a brief presentation of the

Experimental Study on the Influence on Vibration Characteristics of Thin Cylindrical Shell with Hard Coating under Cantilever Boundary Condition

Directory of Open Access Journals (Sweden)

Hui Li

2017-01-01

Full Text Available This research has experimentally investigated the influence on vibration characteristics of thin cantilever cylindrical shell (TCS with hard coating under cantilever boundary condition. Firstly, the theoretical model of TCS with hard coating is established to calculate its natural frequencies and modal shapes so as to roughly understand vibration characteristic of TCS when it is coated with hard coating material. Then, by considering its nonlinear stiffness and damping influences, an experiment system is established to accurately measure vibration parameters of the shell, and the corresponding test methods and identification techniques are also proposed. Finally, based on the measured data, the influences on natural frequencies, modal shapes, damping ratios, and vibration responses of TCS with hard coating are analyzed and discussed in detail. It can be found that hard coating can play an important role in vibration reduction of TCS, and for the most modes of TCS, hard coating will result in the decrease of natural frequencies, but the decreased level is not very big, and its damping effects on the higher frequency range of the shell are weak and ineffective. Therefore, in order to make better use of this coating material, we must carefully choose the concerned antivibration frequency range of the shell; otherwise it may lead to some negative effects.

Development of ITER diagnostics: Neutronic analysis and radiation hardness

Energy Technology Data Exchange (ETDEWEB)

Vukolov, Konstantin, E-mail: vukolov_KY@nrcki.ru; Borisov, Andrey; Deryabina, Natalya; Orlovskiy, Ilya

2015-10-15

Highlights: • Problems of ITER diagnostics caused by neutron radiation from hot DT plasma considered. • Careful neutronic analysis is necessary for ITER diagnostics development. • Effective nuclear shielding for ITER diagnostics in the 11th equatorial port plug proposed. • Requirements for study of radiation hardness of diagnostic elements defined. • Results of optical glasses irradiation tests in a fission reactor given. - Abstract: The paper is dedicated to the problems of ITER diagnostics caused by effects of radiation from hot DT plasma. An effective nuclear shielding must be arranged in diagnostic port plugs to meet the nuclear safety requirements and to provide reliable operation of the diagnostics. This task can be solved with the help of neutronic analysis of the diagnostics environment within the port plugs at the design stage. Problems of neutronic calculations are demonstrated for the 11th equatorial port plug. The numerical simulation includes the calculations of neutron fluxes in the port-plug and in the interspace. Options for nuclear shielding, such as tungsten collimator, boron carbide and water moderators, stainless steel and lead screens are considered. Data on neutron fluxes along diagnostic labyrinths allow to define radiation hardness requirements for the diagnostic components and to specify their materials. Options for windows and lenses materials for optical diagnostics are described. The results of irradiation of flint and silica glasses in nuclear reactor have shown that silica KU-1 and KS-4V retain transparency in visible range after neutron fluence of 10{sup 17} cm{sup −2}. Flints required for achromatic objectives have much less radiation hardness about 5 × 10{sup 14} n/cm{sup 2}.

Hazards of the ‘Hard Cash’: Hypersensitivity Pneumonitis

Directory of Open Access Journals (Sweden)

Elif Kupeli

2010-01-01

Full Text Available 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.

Shock compression synthesis of hard materials

Energy Technology Data Exchange (ETDEWEB)

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

1999-03-01

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

The relationship between hardness to the tensile properties of kenaf/ unsaturated polyester composite

Science.gov (United States)

Ghaztar, Muhammad Mustakim Mohd; Romli, Ahmad Zafir; Ibrahim, Nik Noor Idayu Nik

2017-12-01

The level of fibre-matrix interaction and consolidation are essential aspects to determine the composite deformation but, less attention is given to the effect of small fibre weight increment (5 wt%), chemical treatment coalition (NaOH/ silane), fibre's length and aspect ratio to the physical and mechanical properties of the composite. Hence, this paper studies the correlation between these parameters towards hardness and tensile properties of Kenaf fibre and unsaturated polyester (UP) matrix. The study was carried out by fabricating the sample into two (2) types of fibre categories and fibre loadings and tested to determine its properties. The results showed that the hardness and tensile stress were significantly influenced by the fibre loading and dispersion of the fabricated samples. At low filler loading, the treated samples for both fibre sizes showed lower hardness property compared to the untreated samples. The chemical treatment coalition might diffuse out the pectin and hemicellulose which affect the ability of the fibre to absorb the force applied by the hardness indenter. Good fibre dispersion observed for the treated samples also resulted in the fibre-dominating composite system where the fibres were efficiently absorbed and distributed the indentation force. However, chemical treatments and good fibre dispersion contributed to the higher tensile stress of the treated fibre samples especially for smaller fibre length and aspect ratio compared to the untreated samples. At high fibre loading, treated fibre samples showed higher hardness property compared to the untreated samples since the treatment resulted in better fibre wetting by the matrix and the formation of pack structure. However, high fibre loading caused the mutual abrasion among the fibre which led to the lower tensile stress compared to the low fibre loading samples. In conclusion, by understanding the factors that influenced the reinforcing mechanism of the composite, the inconsistency of

Hardness of carbides, nitrides, and borides

International Nuclear Information System (INIS)

Schroeter, W.

1981-01-01

Intermetallic compounds of metals with non-metals such as C, N, and B show different hardness. Wagner's interaction parameter characterizes manner and extent of the interaction between the atoms of the substance dissolved and the additional elements in metallic mixed phases. An attempt has been made to correlate the hardness of carbides, nitrides, and borides (data taken from literature) with certain interaction parameters and associated thermodynamic quantities (ΔH, ΔG). For some metals of periods 4, 5, and 6 corresponding relations were found between microhardness, interaction parameters, heat of formation, and atomic number

Hardness distribution and tensile properties in an electron-beam-welded F82H irradiated in HFIR

International Nuclear Information System (INIS)

Hashimoto, N.; Oka, H.; Muroga, T.; Kimura, A.; Sokolov, M.A.; Yamamoto, T.

2014-01-01

F82H-IEA and its EB-weld joint were irradiated at 573 and 773 K up to 9.6 dpa in the HFIR and the irradiation effect on its mechanical properties and microstructure were investigated. A hardness profile across the weld joint before irradiation showed the hardness in transformed region (TR) was high and especially that in the edge of TR was the highest (high hardness region: HHR) compared to base metal. This hardness distribution corresponds to grain size distribution. After irradiation, hardening in HHR was small compared to other region in the sample. In tensile test, the amount of hardening in yield strength and ultimate tensile strength of F82H EB-weld joint was almost similar to that of F82H-1EA but the fracture position of EB-weld joint was at the boundary of TR and BM. Therefore, the TR/BM boundary is the structural weak point in F82H EB-weld joint after irradiation. As the plastic instability was observed, the dislocation channeling deformation can be expected though the dislocation channel was not observed in this study. (author)

High performance sinter-HIP for hard metals

International Nuclear Information System (INIS)

Hongxia Chen; Deming Zhang; Yang Li; Jingping Chen

2001-01-01

The horizontal sinter-HIP equipment with great charge capacity and high performance, developed and manufactured by Central Iron and Steel Research Institute(CISRI), is mainly used for sintering and condensation of hard metals. This equipment is characterized by large hot zone, high heating speed, good temperature uniformity and fast cooling system. The equipment can provide uniform hot zone with temperature difference less than 6 o C at 1500-1600 o C and 6-10 MPa by controlling temperature, pressure and circulation of gas precisely. Using large scale horizontal sinter-HIP equipment to produce hard matals have many advantages such as stable quality, high efficiency of production, high rate of finished products and low production cost, so this equipment is a good choice for manufacturer of hard metals. (author)

Correlation between yield stress and hardness of nickel–silicon–boron-based alloys by nanoindentation

International Nuclear Information System (INIS)

Şerban, Viorel-Aurel; Codrean, Cosmin; Vodă, Mircea; Chicot, Didier; Decoopman, Xavier

2014-01-01

Based on the relation proposed by Tabor in 1951, which connects the ultimate tensile strength and the yield stress of classical materials to the Brinell or Vickers hardness numbers by a simple factor of proportionality, we propose an extended analytical model for the determination of the yield stress of brittle materials using nanoindentation data. This model considers the nanoindentation hardness calculated from the projected actual contact area between the indenter and the material which is representative of the real mean pressure exerted by the indenter compared to classical hardness numbers. A coefficient is introduced in the model to integrate the extent of the elastic recovery of the indented material occurring after the withdrawal of the indenter. This is possible by using the criterion defined by the residual to maximum indenter displacements ratio, this criterion being already related to the deformation mode under indentation. Indeed, this criterion allows identifying the piling-up deformation observed for complete or fully plastic deformation materials or the sinking-in deformation for purely elastic materials. The proposed model thus allows a good estimation of the yield stress of brittle materials for which classical tensile tests are not applicable. The model is validated on a variety of amorphous nickel–silicon-based alloy ribbons, i.e., Ni 89 Si 9 B 2 , Ni 78 Si 9 B 13 and Ni 68 Fe 3 Cr 7 Si 8 B 14 on which both nanoindentation tests and tensile experiments have been performed

Technology skills assessment for deaf and hard of hearing students in secondary school.

Science.gov (United States)

Luft, Pamela; Bonello, Mary; Zirzow, Nichole K

2009-01-01

To BE COMPETITIVE in the workplace, deaf and hard of hearing students must not only possess basic computer literacy but also know how to use and care for personal assistive and listening technology. An instrument was developed and pilot-tested on 45 middle school and high school deaf and hard of hearing students in 5 public school programs, 4 urban and 1 suburban, to assess these students' current technology skills and to prepare them for post-high school expectations. The researchers found that the students' computer skills depended on their access to technology, which was not always present in the schools. Many students also did not know basic care practices or troubleshooting techniques for their own personal hearing aids (if worn), or how to access or use personal assistive technology.

Ductility, strength and hardness relation after prior incremental deformation (ratcheting) of austenitic steel

International Nuclear Information System (INIS)

Kussmaul, K.; Diem, H.K.; Wachter, O.

1993-01-01

Experimental investigations into the stress/strain behavior of the niobium stabilized austenitic material with the German notation X6 CrNiNb 18 10 proved that a limited incrementally applied prior deformation will reduce the total deformation capability only by the amount of the prior deformation. It could especially be determined on the little changes in the reduction of area that the basically ductile deformation behavior will not be changed by the type of the prior loading. There is a correlation between the amount of deformation and the increase in hardness. It is possible to correlate both the changes in hardness and the material properties. In the case of low cycle fatigue tests with alternating temperature an incremental increase in total strain (ratcheting) was noted to depend on the strain range applied

Standard test method for dynamic tear testing of metallic materials

CERN Document Server

American Society for Testing and Materials. Philadelphia

1983-01-01

1.1 This test method covers the dynamic tear (DT) test using specimens that are 3/16 in. to 5/8 in. (5 mm to 16 mm) inclusive in thickness. 1.2 This test method is applicable to materials with a minimum thickness of 3/16 in. (5 mm). 1.3 The pressed-knife procedure described for sharpening the notch tip generally limits this test method to materials with a hardness level less than 36 HRC. Note 1—The designation 36 HRC is a Rockwell hardness number of 36 on Rockwell C scale as defined in Test Methods E 18. 1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Water hardness reduces the accumulation and toxicity of uranium in a freshwater macrophyte (Ceratophyllum demersum)

Energy Technology Data Exchange (ETDEWEB)

Markich, Scott J., E-mail: smarkich@optusnet.com.au

2013-01-15

There is a lack of good quality data and mechanistic understanding on the effects of true water hardness (calcium (Ca) and magnesium (Mg)) on the bioavailability and toxicity of uranium (U) to freshwater biota. This study determined the effect of true water hardness (20, 75, 150, 275 and 400 mg CaCO{sub 3} L{sup −1}) on the cell surface binding affinity (log K), accumulation and toxicity (growth inhibition) of U in a submerged, rootless, macrophyte (Ceratophyllum demersum) in a synthetic freshwater with constant alkalinity (13 mg CaCO{sub 3} L{sup −1}) and pH (6.2) over 7 days. A 20-fold increase in water hardness resulted in a 4-fold decrease in U toxicity (median effect concentration (EC50) = 134 μg L{sup −1} U at 20 mg CaCO{sub 3} L{sup −1} hardness, increasing to 547 μg L{sup −1} U at 400 mg CaCO{sub 3} L{sup −1} hardness), cell surface binding affinity (log K = 6.25 at 20 mg CaCO{sub 3} L{sup −1} hardness, decreasing to log K = 5.64 at 400 mg CaCO{sub 3} L{sup −1} hardness) and accumulation (the concentration factor decreased from 63 at 20 mg CaCO{sub 3} L{sup −1} hardness to 15 at 400 mg CaCO{sub 3} L{sup −1} hardness) of U. Calcium provided a 4-fold greater protective effect against U accumulation and toxicity compared to Mg. Speciation calculations indicated negligible differences in the percentages of key U species (UO{sub 2}{sup 2+}, UO{sub 2}OH{sup +}, UO{sub 2}(OH){sub 2}) over the range of water hardness tested. The inhibition of U binding at the cell surface, and subsequent uptake, by C. demersum, with increasing Ca and/or Mg concentration, may be explained in terms of (i) competition between Ca{sup 2+}/Mg{sup 2+} and UO{sub 2}{sup 2+} (and/or UO{sub 2}OH{sup +}) for physiologically active sites at the cell surface, and/or (ii) reduced negative charge (electrical potential) at the cell surface, resulting in a decrease in the activity of UO{sub 2}{sup 2+} (and/or UO{sub 2}OH{sup +}) at the plant/water interface (boundary layer

Design of a scattering polarimeter for hard X-ray astronomy

International Nuclear Information System (INIS)

Costa, E.; Cinti, M.N.; Feroci, M.; Matt, G.; Rapisarda, M.

1995-01-01

The design of a new hard X-ray Compton scattering polarimeter based on scintillating fibre technology is presented and studied in detail by means of Monte Carlo calculations. Several different configurations and materials have been tested in order to optimise the sensitivity in the medium/high energy X-ray band. A high sensitivity over the energy band 20-200 keV is obtained for a two material configuration. The advantages deriving from employing a new scintillating material, the YAP (YAlO 3 ), are also discussed. (orig.)

Microstructure and Hardness Distribution of Resistance Welded Advanced High Strength Steels

DEFF Research Database (Denmark)

Pedersen, Kim Richardt; Harthøj, Anders; Friis, Kasper Leth

2008-01-01

In this work a low carbon steel and two high strength steels (DP600 and TRIP700) have been resistance lap welded and the hardness profiles were measured by micro hardness indentation of cross sections of the joint. The resulting microstructure of the weld zone of the DP-DP and TRIP-TRIP joints were...... found to consist of a martensitic structure with a significant increase in hardness. Joints of dissimilar materials mixed completely in the melted region forming a new alloy with a hardness profile lying in between the hardness measured in joints of the similar materials. Furthermore the joints were...

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

Directory of Open Access Journals (Sweden)

P. van der Merwe

2007-07-01

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