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1

Coal as a Substitute for Carbon Black  

NASA Technical Reports Server (NTRS)

New proposal shows sprayed coal powder formed by extrusion of coal heated to plastic state may be inexpensive substitute for carbon black. Carbon black is used extensively in rubber industry as reinforcing agent in such articles as tires and hoses. It is made from natural gas and petroleum, both of which are in short supply.

Kushida, R. O.

1982-01-01

2

30 CFR 56.6901 - Black powder.  

...Resources 1 2014-07-01 2014-07-01 false Black powder. 56.6901 Section 56.6901 Mineral... Explosives General Requirements § 56.6901 Black powder. (a) Black powder shall be used for blasting only when a...

2014-07-01

3

30 CFR 57.6901 - Black powder.  

...Resources 1 2014-07-01 2014-07-01 false Black powder. 57.6901 Section 57.6901 Mineral...Requirements-Surface and Underground § 57.6901 Black powder. (a) Black powder shall be used for blasting only when a...

2014-07-01

4

49 CFR 173.170 - Black powder for small arms.  

... 2 2014-10-01 2014-10-01 false Black powder for small arms. 173.170 Section 173...Materials Other Than Class 1 and Class 7 § 173.170 Black powder for small arms. Black powder for small arms that has been...

2014-10-01

5

Neutron powder diffraction studies of silicon-substituted hydroxyapatite.  

PubMed

The incorporation of a small amount of silicon in the hydroxyapatite (HAp) lattice is known to improve the bioactivity of the material. The effect of silicon substitution was studied by comparing samples of pure and 0.4wt% silicon-substituted HAp prepared by an aqueous precipitation method. High-resolution neutron powder diffraction and Rietveld refinement methods were used to investigate the effect of silicon substitution on the crystal structure parameters of the HAp lattice from room temperature down to 20K. Small structural changes in the lattice constants, interatomic distances, site occupancies and distortion of the phosphate tetrahedron were found. Modifications of the Fourier transform infrared spectra as well as appearance of new modes were observed in the silicon-substituted sample. Heat treatment and silicon substitution also affected the morphology and crystallinity of this bioapatite. PMID:12853251

Leventouri, Th; Bunaciu, C E; Perdikatsis, V

2003-10-01

6

40 CFR 721.10150 - Carbon black, (4-methylphenyl)-modified, substituted (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon black, (4-methylphenyl)-modified, substituted...Chemical Substances § 721.10150 Carbon black, (4-methylphenyl)-modified, substituted...substance identified generically as carbon black,...

2010-07-01

7

40 CFR 721.10149 - Carbon black, (3-methylphenyl)-modified, substituted (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon black, (3-methylphenyl)-modified, substituted...Chemical Substances § 721.10149 Carbon black, (3-methylphenyl)-modified, substituted...substance identified generically as carbon black,...

2010-07-01

8

Spherical Granule Production from Micronized Saltwort (Salicornia herbacea) Powder as Salt Substitute  

PubMed Central

The whole saltwort plant (Salicornia herbacea) was micronized to develop the table salt substitute. The micronized powder was mixed with distilled water and made into a spherical granule by using the fluid-bed coater (SGMPDW). The SGMPDW had superior flowability to powder; however, it had low dispersibility. To increase the dispersibility of SGMPDW, the micronized powder was mixed with the solution, which contained various soluble solid contents of saltwort aqueous extract (SAE), and made into a spherical granule (SGMPSAE). The SGMPSAE prepared with the higher percentages of solid content of SAE showed improved dispersibility in water and an increase in salty taste. The SGMPSAE prepared with 10% SAE was shown to possess the best physicochemical properties and its relative saltiness compared to NaCl (0.39). In conclusion, SGMPSAEs can be used as a table salt substitute and a functional food material with enhanced absorptivity and convenience. PMID:24471111

Shin, Myung-Gon; Lee, Gyu-Hee

2013-01-01

9

Influence of Mg-substitution on the physicochemical properties of calcium phosphate powders  

SciTech Connect

Tricalcium phosphate based ceramics (TCP) are bioresorbable and thereby considered to be promising bone replacement materials. The differences in crystal structure between {alpha} and {beta}-TCP phases gives rise for different dissolution rates in vitro and in vivo, which may alter the bioresorbable behavior of TCP ceramics. It is suggested that the addition of magnesium ions, which are also present in biological tissues, stabilizes {beta}-phase to higher temperatures and thus enables the sintering of {beta}-TCP at elevated temperatures compared to Mg free TCP. In this paper, Mg-substituted TCP, with the general formula (Ca{sub 1-x}Mg {sub x}){sub 3}(PO{sub 4}){sub 2} and 0.01 {<=} x {<=} 0.045, were produced by wet chemical synthesis from Ca(OH){sub 2}, H{sub 3}PO{sub 4} and MgO, after calcinations at three different temperatures between 750 and 1050 deg. C. The influence of different amounts of Mg substitution on the physical properties, microstructure, and sintering behavior of calcium phosphate powders was evaluated. Thermal analytical techniques, together with X-ray diffraction analysis, were successfully combined in order to characterize the occurring phase transformations during annealing of the powders. The results show that the addition of small amounts of Mg (up to 1.5 mol%) are adequate to postpone the {beta}-{alpha} TCP phase transformation to 1330 deg. C and to accelerate the densification process during sintering of {beta}-TCP ceramics.

Marchi, J. [University of Erlangen-Nuernberg, Department of Materials Science-Biomaterials, Henkestr. 91, D-91052 Erlangen (Germany); Institute of Energetic and Nuclear Research (IPEN), Centre of Science and Materials Technology, Department of Ceramics, Av. Prof. Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Dantas, A.C.S. [University of Erlangen-Nuernberg, Department of Materials Science-Biomaterials, Henkestr. 91, D-91052 Erlangen (Germany); Greil, P. [University of Erlangen-Nuernberg, Department of Materials Science-Biomaterials, Henkestr. 91, D-91052 Erlangen (Germany); Bressiani, J.C. [Institute of Energetic and Nuclear Research (IPEN), Centre of Science and Materials Technology, Department of Ceramics, Av. Prof. Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Bressiani, A.H.A. [Institute of Energetic and Nuclear Research (IPEN), Centre of Science and Materials Technology, Department of Ceramics, Av. Prof. Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Mueller, F.A. [University of Erlangen-Nuernberg, Department of Materials Science-Biomaterials, Henkestr. 91, D-91052 Erlangen (Germany)]. E-mail: Frank.Mueller@ww.uni-erlangen.de

2007-06-05

10

Organo-montmorillonite as substitute of carbon black in natural rubber compounds  

Microsoft Academic Search

The use of octadecylamine modified montmorillonite as substitute of carbon black in natural rubber (NR) compounds is studied. Rubber with 10 parts per hundred resin (phr) of pristine (clay) and octadecylamine modified montmorillonite (organoclay) were compared with 10 and 40phr carbon black as filler. The modified silicate is analysed by X-ray, FTIR and thermogravimetric analysis. Vulcametric curves show that the

M Arroyo; M. A López-Manchado; B Herrero

2003-01-01

11

40 CFR 721.10075 - Carbon black, 4-[[2-(Sulfooxy) ethyl]substituted] phenyl- modified, sodium salts (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon black, 4-[[2-(Sulfooxy) ethyl]substituted...Chemical Substances § 721.10075 Carbon black, 4-[[2-(Sulfooxy) ethyl]substituted...substance identified generically as carbon black, 4-[[2-(Sulfooxy)...

2010-07-01

12

The substitution of nickel for cobalt in hot isostatically pressed powder metallurgy UDIMET 700 alloys  

NASA Technical Reports Server (NTRS)

Nickel was substituted in various proportions for cobalt in a series of five hot-isostatically-pressed powder metallurgy alloys based on the UDIMET 700 composition. These alloys were given 5-step heat treatments appropriate for use in turbine engine disks. The resultant microstructures displayed three distinct sizes of gamma-prime particles in a gamma matrix. The higher cobalt-content alloys contained larger amounts of the finest gamma-prime particles, and had the lowest gamma-gamma-prime lattice mismatch. While all alloys had approximately the same tensile properties at 25 and 650 gamma C, the rupture lives at 650 and 760 C peaked in the alloys with cobalt contents between 12.7 and 4.3 pct. Minimum creep rates increased as cobalt contents were lowered, suggesting their correlation with the gamma-prime particle size distribution and the gamma-gamma-prime mismatch. It was also found that, on overaging at temperatures higher than suitable for turbine disk use, the high cobalt-content alloys were prone to sigma phase formation.

Harf, F. H.

1985-01-01

13

Structural and optical absorption studies of barium substituted strontium ferrite powder  

NASA Astrophysics Data System (ADS)

Attempt has been made to synthesize BaxSr1-xFeO3-? (x = 0-1.0) ferrite powder by decomposition of sol-gel derived oxalate at 800-1000 °C for 5-10 h to study the effect of barium insertion with regard to phase(s), stability, optical behavior, oxidation states of iron, and oxygen deficiency. It is shown that these ferrites possess a perovskite-type cubic phase (a = 3.877-4.020Å, Z = 1, space group Pm3m) for 0.1 ? x ? 0.94, a mixture of 82% rhombohedral (aR = 5.666Å and ?R = 59.761°, Z = 2, space group R3c) and 18% hexagonal phases for x = 0.96 and a pure hexagonal (a = 5.689Å, c = 13.944Å, Z = 6, space group P63/mmc) phase for x = 1. Barium substitution in SrFeO3-? system leads to lattice expansion, weakening of the metal-oxygen bond, reduction of tetravalent iron ions (as evident from Mossbauer analysis), and decrease of oxygen content. The optical absorption peaks observed in the range 3.17-4.11 eV are attributed to charge transfer transitions from O2- (2p) to Fe (3d) band. The values of optical energy band gap of BaxSr1-xFeO3-? are found to be ˜5.48 and ˜4.04 for x = 0.1 and 1.0, respectively. A stable perovskite-type cubic phase in BaxSr1-xFeO3-? system with significant anion deficiency (? = 0.26-0.32) may possibly act as an oxygen permeable membrane.

Jaiswal, Shivendra Kumar; Kumar, Jitendra

2012-08-01

14

Investigation of Ga substitution in ZnO powder and opto-electronic properties.  

PubMed

Two sets of Ga-doped ZnO powders were synthesized via solid-state and Pechini routes with a substitution rate varying from 0 to 4 mol %. The gallium solubility limit is strongly dependent on the synthesis history. Indeed, a low temperature annealing allows incorporating about 1.5 mol % (X-ray diffraction (XRD), inductive coupled plasma spectroscopy (ICP), optical properties) whereas under 0.1% of dopant is introduced after thermal treatment at high temperature: 1500 degrees C (from XRD and pellets conductivity). The incorporation of gallium leads to an anisotropic distortion of the zincite crystal lattice (a and c parameters increase and decrease, respectively, versus the Ga content leading to a decrease of the c/a ratio) which can be explained from the valence bond model. XRD analysis, chemical titration by ICP, and conductivity measurements (on pellets obtained at high temperature) allow determining accurately the maximum Ga content in the zincite. The optical properties (IR absorption efficiency) linked to electron carriers are directly correlated to the gallium rate introduced in ZnO oxide; nevertheless, the non linear correlation between these two parameters tends to show that the concentration of charge carriers in the system is not equal to the amount of Ga(3+) atoms inserted per ZnO volume unit. A saturation regime is observed and was here explained once again on the basis of the valence band model by the increase of inhibiting p type defects with the increase of (n-type donors) Ga(3+) concentration. PMID:20593782

Serier, Hélène; Demourgues, Alain; Gaudon, Manuel

2010-08-01

15

THE COMPARISON PROPERTIES OF RECYCLE RUBBER POWDER, CARBON BLACK, AND CALCIUM CARBONATE FILLED NATURAL RUBBER COMPOUNDS  

Microsoft Academic Search

The effects of filler loading on the curing characteristics, swelling behavior, and mechanical properties of natural rubber compounds were studied using a conventional vulcanization system. Recycle rubber powder (RRP), carbon black (CB) (N550), and calcium carbonate (CaCO3) were used as fillers and the loading range was from 0 to 50 phr. Results show that the scorch time, t2, and cure time,

Hanafi Ismail; R. Nordin

2002-01-01

16

Synthesis of tungsten carbide by dynamic shock compression of a tungsten–acetylene black powder mixture  

Microsoft Academic Search

In order to synthesize tungsten carbide as a high-temperature structural element by a shock wave technique, a tungsten–acetylene black powder mixture was shock-compressed. The retrieved sample was examined by X-ray diffraction analysis and optical\\/electron microscopy. A rodlike compact consisting of rounded particles, plates and dendritic particles of WC having a hexagonal structure was formed in the central region of the

Kenjiro Yamada

2000-01-01

17

40 CFR 721.10080 - Carbon black, 4-[(17-substituted-3,6,9,12,15-pentaazaheptadec-1-yl) substituted] phenyl-modified...  

Code of Federal Regulations, 2010 CFR

. (1) The chemical substance identified generically as carbon black, 4-[(17-substituted-3,6,9,12,15-pentaazaheptadec-1-yl) substituted] phenyl-modified, hydrochlorides (PMN P-06-8) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this...

2010-07-01

18

(210)Pb content in natural gas pipeline residues ("black-powder") and its correlation with the chemical composition.  

PubMed

The present work was carried out to assess the (210)Pb content in "black-powder" found in pigging operations on gas pipelines in Brazil, in particular, on the Campos Basin gas pipeline. Additionally, the chemical composition of such deposits was determined and an eventual correlation with (210)Pb concentration evaluated. Typical "black-powder" generated in the natural gas pipeline from Campos Basin oilfield contains mainly iron oxide ( approximately 81%) and residual organic matter ( approximately 9%). The (210)Pb content ranges from 4.9 to 0.04k Bqkg(-1) and seems to be inversely correlated with the distance to the platforms. On the other hand, (226)Ra concentration is higher on the pipeline branch between the platform and the onshore installations. (228)Ra was only observed in few samples, in particular, in the samples with the highest (226)Ra content. PMID:15885858

Godoy, José Marcus; Carvalho, Franciane; Cordilha, Aloisio; Matta, Luiz Ernesto; Godoy, Maria Luiza

2005-01-01

19

Large scale production of yolk-shell ?-tricalcium phosphate powders, and their bioactivities as novel bone substitutes.  

PubMed

This paper proposes the production of yolk-shell structured ?-tricalcium phosphate (?-TCP) powders using a spray-drying method, suitable for commercial scale production. Spray-dried precursor powders, consisting of calcium-phosphate salts and each of the various carbon source materials, are combusted in an oxygen atmosphere to obtain a yolk-shell structure. Only dextrin among the carbon source materials investigated shows promise in the production of ?-TCP yolk-shell powders. By evaluating their apatite-forming capacity in simulated body fluid, the outstanding bioactivity of ?-TCP yolk-shell powders is confirmed: numerous acicular and newly formed hydroxyl carbonate apatite crystals cover the entire ?-TCP surface after a single day of soaking. These crystals are observed on both the outer and inner surfaces of the shells, and on the outer surface of the core, which is encouraging for its potential use as a bone grafting material. PMID:25005151

Cho, Jung Sang; Lee, Jong-Heun; Kang, Yun Chan

2014-08-28

20

Evaluating the effects of amylose and Concord grape extract powder substitution on physicochemical properties of wheat flour extrudates produced at different temperatures.  

PubMed

In this study, the effects of Concord grape extract powder (CGEP), high-amylose starch, and their combinations on quality parameters of extruded products were investigated by substituting wheat flour with those ingredients in the formulations. Physical quality parameters such as water absorption, bulk density, diametric expansion and hardness of extrudates were evaluated in addition to thermal properties, pasting properties and resistant starch contents. Average values obtained for 90, 120 and 150 °C extrusion temperatures changed respectively as follows: 0.916, 0.987 and 0.467 N for hardness; 2.12, 4.07 and 5.12 ml water/g sample for water absorption; 1.35, 2.09 and 2.51 for diametric expansions and 1286.6, 723.6 and 311.1 kg/m(3) for bulk densities. Extrusion temperature was found to have more distinct effect on physical quality parameters of extrudates than the substitution level of ingredients. Both CGEP and amylose additions negatively affected pasting properties, slightly affected resistant starch content and prevented gelatinization. However retardation of retrogradation was more evident when substitution was with CGEP alone rather than its combination with amylose. PMID:24679807

Tacer-Caba, Zeynep; Nilufer-Erdil, Dilara; Boyacioglu, M Hikmet; Ng, Perry K W

2014-08-15

21

Synthesis of Al4SiC4 powders from kaolin grog, aluminum and carbon black by carbothermal reaction  

NASA Astrophysics Data System (ADS)

In this paper, the synthesis of Al4SiC4 used as natural oxide materials by carbothermal reduction was investigated in order to explore the synthesis route with low costs. The samples were calcined by using kaolin grog, aluminum and carbon black as raw materials with the selected proportion at the temperature from 1500 to 1800 ° C for 2 hours under flow argon atmosphere. The phase composition of reaction products were determined by X-ray diffraction. The microstructure and elemental composition of different phases were observed and identified by scanning electron microscopy and energy dispersive spectroscopy. The mechanism of reaction processing was discussed. The results show that Al4SiC4 powders composed of hexagonal plate-like particulates with various sizes and the thickness of less than 20 ?m are obtained when the temperature reaches 1800 °C.

Yuan, Wenjie; Yu, Chao; Deng, Chengji; Zhu, Hongxi

2013-12-01

22

Synthesis of Black and Red Mercury Sulfide Nano-Powder by Traditional Indian Method for Biomedical Application  

NASA Astrophysics Data System (ADS)

The use of metals and minerals in the traditional Indian system of medicine known as aired is very common and is practiced since seventh century B.C. Metals were reduced to calcined powder form for medicinal purpose. For detoxification, a further step of purification of the metals and minerals with different vegetable extracts was practiced. The people of East India were using mercury and its sulfide as medicine. Gradually this secret was leaked to Arabic physicians who used mercury in skin ointment. Subsequently Italian Physicians adopted Arabic prescriptions of mercurial ointments for skin diseases. In the olden days, metals and minerals were impregnated with decoction and juice of vegetables and animal products like milk and fat for purification. These were then reduced to fine particles by milling with a pestle and mortar. It was known by then that the fineness of the powder had a significant influence on the color, texture, and medicinal properties as is cited by Charak. Nagarjun studied in detail the processing of metals and minerals, particularly mercury and the influence of the processing parameters on the medicinal values. Mercury is unique in many aspects. Indian alchemy developed a wide variety a chemical processes for the ostensible transmutation of metals and preparation of elixir of life, in which mercury occupied a prime position .The present investigation attempts to use the traditional methods as prescribed in the ancient texts to prepare mercury sulfide in both red and black form for medicinal use. XRD, SEM and HRTEM investigations of the sulfides obtained shows that the ancient Indians were able to produce nano-sized powders. Possibly this may be taken as the earliest application of the production and use of nano powder. The study proves that even in ancient time the knowledge of nano particle synthesis was prevalent and used to enhance effectiveness of medicines. Further mercury in the free form is not acceptable in medicines. The ancient physicians could get rid of free mercury by milling and proper choice of the ratio of ingredients as is shown in the investigation by X-ray diffraction studies. In the traditional method for synthesis of mercury sulfide, mercury and pure sulfur were taken and milled in a mortar and pastel. During milling process, the white mercury and yellow sulfur yielded to a gray black colored sulfide. Synthesis of red sulfide of mercury required additional steps of heating and subsequent milling. For therapeutically application, the sulfide thus obtained needed detoxification, which was done using organic extracts. In the present investigation, the same method was followed to synthesize the sapphires and the product was characterized using modern methods like XRD, SEM and HRTEM. With increase in milling time the fineness of the powder increases, which increases the efficacy of the medicine, and free mercury, which is not desirable for medicinal application is found to decrease. The powder obtained at the end of 48 hours of milling is found to be of a size finer than l0nm.

Padhi, Payodhar; Sahoo, G.; Das, K.; Ghosh, Sudipto; Panigrahi, S. C.

2008-10-01

23

Dielectric Characteristics of E-glass-Polyester Composite Containing Conductive Carbon Black Powder  

Microsoft Academic Search

The electromagnetic (EM) absorption or shielding characteristics of a material is an important issue not only for military purposes but also for commercial use such as in radar, electric and telecommunication devices. Nowadays studies on investigating the radar absorbing structures (RAS) using fiber reinforced polymeric (FRP) composites are becoming a popular research field. Since carbon black is widely used for

Woo Seok Chin; Dai Gil Lee

2007-01-01

24

Study of isotopic variations in black powder: reflections on the use of stable isotopes in forensic science for source inference.  

PubMed

Isotope ratio mass spectrometry (IRMS) has recently made its appearance in the forensic community. This high-precision technology has already been applied to a broad range of forensic fields such as illicit drugs, explosives and flammable liquids, where current, routinely used techniques have limited powers of discrimination. The conclusions drawn from the majority of these IRMS studies appear to be very promising. Used in a comparative process, as in food or drug authentication, the measurement of stable isotope ratios is a new and remarkable analytical tool for the discrimination or the identification of a substance with a definite source or origin. However, the research consists mostly of preliminary studies. The significance of this 'new' piece of information needs to be evaluated in light of a forensic framework to assess the actual potential and validity of IRMS, considering the characteristics of each field. Through the isotopic study of black powder, this paper aims at illustrating the potential of the method and the limitations of current knowledge in stable isotopes when facing forensic problems. PMID:19603456

Gentile, Natacha; Siegwolf, Rolf T W; Delémont, Olivier

2009-08-30

25

Effects of pyriproxyfen spray, powder, and oral bait treatments on the relative abundance of fleas (Siphonaptera: Ceratophyllidae) in black-tailed prairie dog (Rodentia: Sciuridae) towns.  

PubMed

Separate black-tailed prairie dog, Cynomys ludovicianus (Ord), towns on the Rocky Mountain Arsenal National Wildlife Refuge, Colorado, were treated with technical pyriproxyfen (Nylar) using spray, powder, and oral bait carriers. Direct combing methods (1997 and 1998) and burrow flagging (1998) were used to estimate relative abundance of the plague vector Oropsylla hirsuta (Baker). Pyriproxyfen spray (0.05%) and powder (0.05%) did not significantly reduce (P > 0.05) O. hirsuta abundance. Pyriproxyfen bait, when applied every 4 wk at a concentration of 286 mg/50 g bait, significantly reduced (P < or = 0.05) O. hirsuta infesting prairie dogs, 4 mo after initial treatment. However, flea populations had recovered to pretreatment levels by the following summer (July 1999). PMID:11126542

Karhu, R; Anderson, S

2000-11-01

26

Processes of microstructural evolution during high-energy mechanical treatment of ZnO and black NiO powder mixture  

NASA Astrophysics Data System (ADS)

Kinetics of microstructural evolution in ZnO and NiO black powder mixture during prolonged high-energy mechanical ball milling were investigated by Scanning Electron Microscopy, Laser Particle Sizer, X-ray diffraction, Electron Paramagnetic Resonance, Fourier Transform Infrared Spectroscopy and UV-vis Diffuse Reflection methods. The use of these methods allows us to control the macrostructural processes (ZnO particles and NiO granules grinding, the deagglomeration and “secondary agglomeration”), the microstructural processes (formation and annealing of different native defects in ZnO [VZn-:Zni0 (I), VZn- (II), and (VZn-)2- (III) centers] and NiO black) and the mechanothermal processes in samples. This allows to establish the relationship between microstructural evolution and the properties of the samples depending on the duration of the mechanical processing.

Kakazey, M.; Vlasova, M.; Vorobiev, Y.; Leon, I.; Cabecera Gonzalez, M.; Chávez Urbiola, Edgar Arturo

2014-11-01

27

Effects of pyriproxyfen spray, powder, and oral bait treatments on the relative abundance of nontarget arthropods of black-tailed prairie dog (Rodentia: Sciuridae) towns.  

PubMed

Separate black-tailed prairie dog, Cynomys ludovicianus (Ord), towns on the Rocky Mountain Arsenal National Wildlife Refuge, Colorado, were treated with technical pyriproxyfen (Nylar) spray, powder, and oral bait. The treatments were applied to reduce relative abundance of the plague vector Oropsylla hirsuta (Baker). Because pyriproxyfen is a juvenile hormone analog, we were also concerned with the effects of the treatments on nontarget arthropods, which is the focus of this study. Pitfall traps and sweep net sampling were used to measure relative abundance of arthropod populations pre- and posttreatment. Nontarget arthropod sampling produced a large number of statistical comparisons that indicated significant declines (P < 0.05) in relative arthropod abundance. Many of the significant declines were probably because of natural fluctuations in arthropod populations rather than treatment effects. Because arthropod populations appeared to fluctuate randomly, we only made inferences about highly significant (P < 0.001) declines. In doing so, we hoped to abate some of the confusion created by the natural fluctuation in arthropod abundance and increase our chance of correctly attributing a population reduction to a treatment effect. Only Homoptera at the pyriproxyfen powder site exhibited highly significant reductions that appeared to be attributed to the treatments. Pyriproxyfen spray treatments did not significantly reduce relative arthropod abundance. PMID:10916304

Karhu, R R; Anderson, S H

2000-07-01

28

The Black Sea Economic Cooperation Project: A Substitute or a Complement to Globalization for the Middle East and the Balkans?  

Microsoft Academic Search

This paper evaluates Black Sea Economic Cooperation (BSEC) from the perspective of globalization efforts in the Middle East and the Balkans, the regions that future expansion scenarios are most likely to cover. For this purpose, the paper investigates the economic rationale behind the desire to seek\\/maintain membership, with special reference to the trade creation and diversion effects it could generate.

Serdar Sayan

1998-01-01

29

Cheap, Gram-Scale Fabrication of BN Nanosheets via Substitution Reaction of Graphite Powders and Their Use for Mechanical Reinforcement of Polymers  

PubMed Central

As one of the most important two-dimensional (2D) materials, BN nanosheets attracted intensive interest in the past decade. Although there are many methods suitable for the preparation of BN sheets, finding a cheap and nontoxic way for their mass and high-quality production is still a challenge. Here we provide a highly effective and cheap way to synthesize gram-scale-level well-structured BN nanosheets from many common graphite products as source materials. Single-crystalline multi-layered BN sheets have a mean lateral size of several hundred nanometers and a thickness ranging from 5?nm to 40?nm. Cathodoluminescence (CL) analysis shows that the structures exhibit a near band-edge emission and a broad emission band from 300?nm to 500?nm. Utilization of nanosheets for the reinforcement of polymers revealed that the Young's modulus of BN/PMMA composite had increased to 1.56?GPa when the BN's fraction was only 2 wt.%, thus demonstrating a 20% gain compared to a blank PMMA film. It suggests that the BN nanosheet is an ideal mechanical reinforcing material for polymers. In addition, this easy and nontoxic substitution method may provide a universal route towards high yields of other 2D materials. PMID:24572725

Liu, Fei; Mo, Xiaoshu; Gan, Haibo; Guo, Tongyi; Wang, Xuebin; Chen, Bin; Chen, Jun; Deng, Shaozhi; Xu, Ningsheng; Sekiguchi, Takashi; Golberg, Dmitri; Bando, Yoshio

2014-01-01

30

Substitution within erythropoietin receptor gene D1 domain associated with litter size in Beijing Black pig, Sus scrofa.  

PubMed

Studies of uterine capacity and litter size in swine have suggested that erythropoietin receptor (EPOR) plays an important role in fetal survival through maturation of red blood cells. In this study, we screened the porcine EPOR gene for mutations and identified three single nucleotide polymorphisms (SNPs): two missense mutations and one synonymous mutation. We then genotyped 272 Beijing Black sows, Sus scrofa, and compared this data with litter sizes from a total of 1523 parities among the sows. The G allele of the nonsynonymous SNP, EPOR c.434A>G, was associated with greater litter size at both first parity (P?Black, Mashen, Meishan and Min) and three Western commercial pig breeds (Duroc, Landrace and Large White). The c.434G allele was significantly more common among the more prolific Chinese breeds than the Western breeds, implying that EPOR c.434A>G could be a useful genetic marker to improve litter size in swine. PMID:21951898

Zhang, Longchao; Wang, Ligang; Li, Yong; Li, Wen; Yan, Hua; Liu, Xin; Zhao, Kebin; Wang, Lixian

2011-10-01

31

Effects of Black Pepper (Piper Nigrum), Turmeric Powder (Curcuma Longa) and Coriander Seeds (Coriandrum Sativum) and Their Combinations as Feed Additives on Growth Performance, Carcass Traits, Some Blood Parameters and Humoral Immune Response of Broiler Chickens  

PubMed Central

Different herbs and spices have been used as feed additives for various purposes in poultry production. This study was conducted to assess the effect of feed supplemented with black pepper (Piper nigrum), turmeric powder (Curcuma longa), coriander seeds (Coriandrum sativum) and their combinations on the performance of broilers. A total of 210 (Cobb) one-d-old chicks were divided into seven groups of 30 birds each. The treatments were: a control group received no supplement, 0.5% black pepper (T1), 0.5% turmeric powder (T2), 2% coriander seeds (T3), a mixture of 0.5% black pepper and 0.5% turmeric powder (T4), a mixture of 0.5% black pepper and 2% coriander seed (T5), and a mixture of 0.5% black pepper, 0.5% turmeric powder and 2% coriander seeds (T6). Higher significant values of body weight gain during the whole period of 5 weeks (p<0.001) were observed in broilers on T1, T3, T5, and T6 compared to control. Dietary supplements with T1, T2, T3, and T6 improved the cumulative G:F of broilers during the whole period of 5 weeks (p<0.001) compared with control. The dressing percentage and edible giblets were not influenced by dietary supplements, while higher values of relative weight of the liver (p<0.05) were obtained in T5 and T6 compared to control. The addition of feed supplements in T5 and T6 significantly increased serum total protein and decreased serum glucose, triglycerides and alkaline phosphatase concentrations compared with the control group (p<0.05). Broilers on T6 showed significant decrease in the serum glutamate pyruvate transaminase concentration (p<0.05) compared to control. The broilers having T5 and T6 supplemented feed had relatively greater antibody titre (p<0.001) at 35 d of age than control. It is concluded that dietary supplements with black pepper or coriander seeds or their combinations enhanced the performance and health status of broiler chickens. PMID:25050023

Abou-Elkhair, R.; Ahmed, H. A.; Selim, S.

2014-01-01

32

Cation substitution in synthetic meridianiite (MgSO4·11H2O) I: X-ray powder diffraction analysis of quenched polycrystalline aggregates  

NASA Astrophysics Data System (ADS)

Meridianiite, MgSO4·11H2O, is the most highly hydrated phase in the binary MgSO4-H2O system. Lower hydrates in the MgSO4-H2O system have end-member analogues containing alternative divalent metal cations (Ni2+, Zn2+, Mn2+, Cu2+, Fe2+, and Co2+) and exhibit extensive solid solution with MgSO4 and with one another, but no other undecahydrate is known. We have prepared aqueous MgSO4 solutions doped with these other cations in proportions up to and including the pure end-members. These liquids have been solidified into fine-grained polycrystalline blocks of metal sulfate hydrate + ice by rapid quenching in liquid nitrogen. The solid products have been characterised by X-ray powder diffraction, and the onset of partial melting has been quantified using a thermal probe. We have established that of the seven end-member metal sulfates studied, only MgSO4 forms an undecahydrate; ZnSO4 forms an orthorhombic heptahydrate (synthetic goslarite), MnSO4, FeSO4, and CoSO4 form monoclinic heptahydrates (syn. mallardite, melanterite, bieberite, respectively), and CuSO4 crystallises as the well-known triclinic pentahydrate (syn. chalcanthite). NiSO4 forms a new hydrate which has been indexed with a triclinic unit cell of dimensions a = 6.1275(1) Å, b = 6.8628(1) Å, c = 12.6318(2) Å, ? = 92.904(2)°, ? = 97.678(2)°, and ? = 96.618(2)°. The unit-cell volume of this crystal, V = 521.74(1) Å3, is consistent with it being an octahydrate, NiSO4·8H2O. Further analysis of doped specimens has shown that synthetic meridianiite is able to accommodate significant quantities of foreign cations in its structure; of the order 50 mol. % Co2+ or Mn2+, 20-30 mol. % Ni2+ or Zn2+, but less than 10 mol. % of Cu2+ or Fe2+. In three of the systems we examined, an `intermediate' phase occurred that differed in hydration state both from the Mg-bearing meridianiite end-member and the pure dopant end-member hydrate. In the case of CuSO4, we observed a melanterite-structured heptahydrate at Cu/(Cu + Mg) = 0.5, which we identify as synthetic alpersite [(Mg0.5Cu0.5)SO4·7H2O)]. In the NiSO4- and ZnSO4-doped systems we characterised an entirely new hydrate which could also be identified to a lesser degree in the CuSO4- and the FeSO4-doped systems. The Ni-doped substance has been indexed with a monoclinic unit-cell of dimensions a = 6.7488(2) Å, b = 11.9613(4) Å, c = 14.6321(5) Å, and ? = 95.047(3)°, systematic absences being indicative of space-group P21/ c with Z = 4. The unit-cell volume, V = 1,176.59(5) Å3, is consistent with it being an enneahydrate [i.e. (Mg0.5Ni0.5)SO4·9H2O)]. Similarly, the new Zn-bearing enneahydrate has refined unit cell dimensions of a = 6.7555(3) Å, b = 11.9834(5) Å, c = 14.6666(8) Å, ? = 95.020(4)°, V = 1,182.77(7) Å3, and the new Fe-bearing enneahydrate has refined unit cell dimensions of a = 6.7726(3) Å, b = 12.0077(3) Å, c = 14.6920(5) Å, ? = 95.037(3)°, and V = 1,190.20(6) Å3. The observation that synthetic meridianiite can form in the presence of, and accommodate significant quantities of other ions increases the likelihood that this mineral will occur naturally on Mars—and elsewhere in the outer solar system—in metalliferous brines.

Fortes, A. Dominic; Browning, Frank; Wood, Ian G.

2012-05-01

33

Photocatalytic degradation of dye naphthol blue black in the presence of zirconia-supported Ti-substituted Keggin-type polyoxometalates  

SciTech Connect

Zirconia-supported Ti-substituted Keggin-type polyoxometalates, Li{sub 5}PW{sub 11}TiO{sub 40}/ZrO{sub 2} (PW{sub 11}Ti/ZrO{sub 2}) and K{sub 7}PW{sub 10}Ti{sub 2}O{sub 40}/ZrO{sub 2} (PW{sub 10}Ti{sub 2}/ZrO{sub 2}), were prepared by incorporating PW{sub 11}Ti and PW{sub 10}Ti{sub 2} cluster into a zirconia matrix via a sol-gel technique. These insoluble and readily separable composites were characterized by DR-UV (DR: diffuse reflectance) and FT-IR spectra, {sup 31}P MAS NMR, ICP-AES, and nitrogen adsorption determination, indicating that the clusters were chemically attached to the zirconia supports, and the primary Keggin structure remained intact. The photocatalytic activity of the supported PW{sub 11}Ti and PW{sub 10}Ti{sub 2} was tested via degradation of an aqueous dye naphthol blue black (NBB). It indicated that the dye NBB can be degraded totally and mineralized into the inorganic products such as CO{sub 2}, NH{sub 4}{sup +}, NO{sub 3}{sup -}, and SO{sub 4}{sup 2-} ions by irradiating the composite slurry in the near-UV area. Dropped of PW{sub 11}Ti or PW{sub 10}Ti{sub 2} cluster from the zirconia matrix into the reaction system was hardly observed during the photocatalytic tests, attributed to the strong chemical interactions between the Keggin units and the zirconia support.

Jiang Chunjie; Guo Yihang; Hu Changwen; Wang Chungang; Li Danfeng

2004-02-02

34

Chemical Preparation of Carbonated Calcium Hydroxyapatite Powders at 37  

E-print Network

Chemical Preparation of Carbonated Calcium Hydroxyapatite Powders at 37 C in Urea-phase ceramic powder. Carbonated HA powders were formed from calcium nitrate tetrahydrate and di- ammonium properties. They were usually observed1 to be carbonate-substituted and calcium-de®cient. Synthetic body

Tas, A. Cuneyt

35

Substitute Solutions.  

ERIC Educational Resources Information Center

In summer 1999, a group of Park City, Utah, school administrators, personnel directors, human-resource specialists, and substitute teacher coordinators brainstormed on improving the recruitment, training, and retention of substitute teachers. Providing effective preservice and on-the-job training and professional recognition are key suggestions.…

Jones, Kevin R.; Hawkins, Amber

2000-01-01

36

Skin Substitutes  

PubMed Central

In a relatively short timespan, a wealth of new skin substitutes made of synthetic and biologically derived materials have arisen for the purpose of wound healing of various etiologies. This review article focuses on providing an overview of skin substitutes including their indications, contraindications, benefits, and limitations. The result of this overview was an appreciation of the vast array of options available for clinicians, many of which did not exist a short time ago. Yet, despite the rapid expansion this field has undergone, no ideal skin substitute is currently available. More research in the field of skin substitutes and wound healing is required not only for the development of new products made of increasingly complex biomolecular material, but also to compare the existing skin substitutes. PMID:25371771

Howe, Nicole; Cohen, George

2014-01-01

37

Energetic powder  

DOEpatents

Fluoroalkylsilane-coated metal particles. The particles have a central metal core, a buffer layer surrounding the core, and a fluoroalkylsilane layer attached to the buffer layer. The particles may be prepared by combining a chemically reactive fluoroalkylsilane compound with an oxide coated metal particle having a hydroxylated surface. The resulting fluoroalkylsilane layer that coats the particles provides them with excellent resistance to aging. The particles can be blended with oxidant particles to form energetic powder that releases chemical energy when the buffer layer is physically disrupted so that the reductant metal core can react with the oxidant.

Jorgensen, Betty S. (Jemez Springs, NM); Danen, Wayne C. (Los Alamos, NM)

2003-12-23

38

Exploring Baking Powder  

NSDL National Science Digital Library

In this activity, learners examine baking powder, a combination of three powders: baking soda, cream of tartar, and cornstarch. Learners use their data from the previous activity (see related resource) to identify these three powders as possible ingredients. Then, they test combinations of these powders to determine the active ingredients in baking powder.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

39

Powder treatment process  

DOEpatents

(1) A process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder.

Weyand, John D. (Greensburg, PA)

1988-01-01

40

Monoalphabetic Substitution  

NSDL National Science Digital Library

This applet, created by Kevin O'Bryant of the University of California - San Diego, illustrates the monoalphabetic substitution codebreaking process using a chi-squared process. The author explains how and why this encryption method is used. Overall, it is a wonderful example of how probability and statistics can be applied to real world situations.

O\\'Bryant, Kevin

2009-12-09

41

Sensory Substitution  

NASA Astrophysics Data System (ADS)

The idea that the cutaneous surface may be employed as a substitute for the eyes and ears is by no means a modern notion. Although the sense of touch has long been considered as a surrogate for both the visual and auditory modalities, the focus of this chapter will be on the efforts to develop a tactile substitute for hearing, especially that of human speech. The visual system is our primary means of processing information about environmental space such as orientation, distance, direction and size. It is much less effective in making temporal discriminations. The auditory system is unparalleled in processing information that involves rapid sequences of temporal events, such as speech and music. The tactile sense is capable of processing both spatial and temporal information although not as effective in either domain as the eye or the ear.

Verrillo, Ronald T.

42

Substitute Teachers  

NSDL National Science Digital Library

Our lives are ones of uncertainty and surprise, yin and yang existences. Some things we can control and others we are powerless to command, even with the best intentions. Teachers are not exempt from emergencies, jury duty, and illness. Luckily, most schools plan for such incidents by having willing substitutes on hand. Teachers need to follow the Scout's motto to "be prepared" and keep the classroom running smoothly and efficiently for students and subs.

Swango, C. J.; Steward, Sally B.

2003-01-01

43

Explicit Substitutions  

Microsoft Academic Search

The ##-calculus is a re#nement of the #-calculus where substitutionsare manipulated explicitly. The ##-calculus provides a settingfor studying the theory of substitutions, with pleasant mathematicalproperties. It is also a useful bridge between the classical #-calculusand concrete implementations.#Digital Equipment Corporation, Systems Research Center.yEcole Normale Sup#erieure; part of this work was completed while at Digital EquipmentCorporation, Systems Research Center.z...

Martín Abadi; Luca Cardelli; Pierre-louis Curien; Jean-jacques Lévy

1991-01-01

44

Preparation of titanium diboride powder  

DOEpatents

Finely-divided titanium diboride or zirconium diboride powders are formed by reacting gaseous boron trichloride with a material selected from the group consisting of titanium powder, zirconium powder, titanium dichloride powder, titanium trichloride powder, and gaseous titanium trichloride.

Brynestad, Jorulf (Oak Ridge, TN); Bamberger, Carlos E. (Oak Ridge, TN)

1985-01-01

45

40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.  

Code of Federal Regulations, 2010 CFR

... Substituted pyridine azo substituted phenyl. 721.8780 Section 721.8780 ...Substituted pyridine azo substituted phenyl. (a) Chemical substance and significant...as substituted pyridine azo substituted phenyl (PMNs P-96-767 and...

2010-07-01

46

Precision powder feeder  

DOEpatents

A new class of precision powder feeders is disclosed. These feeders provide a precision flow of a wide range of powdered materials, while remaining robust against jamming or damage. These feeders can be precisely controlled by feedback mechanisms.

Schlienger, M. Eric (Albuquerque, NM); Schmale, David T. (Albuquerque, NM); Oliver, Michael S. (Sandia Park, NM)

2001-07-10

47

Composite powder particles  

NASA Technical Reports Server (NTRS)

A liquid coating composition including a coating vehicle and composite powder particles disposed within the coating vehicle. Each composite powder particle may include a magnesium component, a zinc component, and an indium component.

Parker, Donald S. (Inventor); MacDowell, Louis G. (Inventor)

2009-01-01

48

Dustiness of Fine and Nanoscale Powders  

PubMed Central

Dustiness may be defined as the propensity of a powder to form airborne dust by a prescribed mechanical stimulus; dustiness testing is typically intended to replicate mechanisms of dust generation encountered in workplaces. A novel dustiness testing device, developed for pharmaceutical application, was evaluated in the dustiness investigation of 27 fine and nanoscale powders. The device efficiently dispersed small (mg) quantities of a wide variety of fine and nanoscale powders, into a small sampling chamber. Measurements consisted of gravimetrically determined total and respirable dustiness. The following materials were studied: single and multiwalled carbon nanotubes, carbon nanofibers, and carbon blacks; fumed oxides of titanium, aluminum, silicon, and cerium; metallic nanoparticles (nickel, cobalt, manganese, and silver) silicon carbide, Arizona road dust; nanoclays; and lithium titanate. Both the total and respirable dustiness spanned two orders of magnitude (0.3–37.9% and 0.1–31.8% of the predispersed test powders, respectively). For many powders, a significant respirable dustiness was observed. For most powders studied, the respirable dustiness accounted for approximately one-third of the total dustiness. It is believed that this relationship holds for many fine and nanoscale test powders (i.e. those primarily selected for this study), but may not hold for coarse powders. Neither total nor respirable dustiness was found to be correlated with BET surface area, therefore dustiness is not determined by primary particle size. For a subset of test powders, aerodynamic particle size distributions by number were measured (with an electrical low-pressure impactor and an aerodynamic particle sizer). Particle size modes ranged from approximately 300nm to several micrometers, but no modes below 100nm, were observed. It is therefore unlikely that these materials would exhibit a substantial sub-100nm particle contribution in a workplace. PMID:23065675

Evans, Douglas E.; Baron, Paul A.

2013-01-01

49

40 CFR Appendix S to Subpart G of... - Substitutes Listed in the September 19, 2012 Final Rule, Effective December 18, 2012.  

Code of Federal Regulations, 2013 CFR

...Conditions Further information Total Flooding Powdered Aerosol F (KSA®) as a substitute...containers or systems to be used in total flooding applications, EPA recommends the following...additional comments 1, 2, 3, 4. Total Flooding Powdered Aerosol G (Dry...

2013-07-01

50

Which Powder is It?  

NSDL National Science Digital Library

In this chemistry challenge, learners identify an unknown white powder by comparing it with common household powders. Learners first explore what happens when baking soda, baking powder, and washing soda are mixed with water, vinegar, and PHTH (the indicator phenolphthalein mixed with alcohol and water). Learners then work to identify the unknown based on how it reacts with the known solutions. This is a simplified form of "qualitative analysis," which was historically an important approach chemists used for identifying unknown samples.

Sciencenter

2014-08-27

51

An examination of the H/D isotope substitution effect on selectivity and activity in the cavitating ultrasound hydrogenation of aqueous 3-buten-2-ol and 1,4-pentadien-3-ol on Pd-black  

SciTech Connect

An H/D isotope effect study of the (H2 versus D2) hydrogenation of the aqueous substrates 3-buten-2-ol (3B2OL) and 1,4-pentadien-3-ol (14PD3OL) was performed using Pd-black catalyst. Either H2O or D2O solvents were employed (for alcohol H/D isotope substitution). Two experimental processing conditions of cavitating ultrasound (CUS) and stirred/silent (SS) methods were used. Products formed include 2-butanol and 2-butanone for the former, and 3-pentanol and 3-pentanone for the latter. The observed selectivity and pseudo-first order reaction rate coefficients (e.g., activity) to these products enabled a mechanistic interpretation of the various reaction conditions to be proposed. Experiments utilized a 50 mL batch reactor maintained at 298 K, employed 5.4 atm of H2 or D2 gas, while seven aliquots were collected during the course of the reaction. We have utilized 1-propanol as an inert dopant in all experiments to enable the rapid onset of cavitation in the CUS systems as described earlier [R.S. Disselkamp et al., J. Catal., 227, 552 (2004)]. The following conclusions were noted. First, the activity of the CUS compared to SS processing were ~100-fold larger. Second, variable catalyst loading experiments for stirred/silent D2 hydrogenation processing indicated that mass transfer of hydrogen gas to the Pd-surface played a role such that higher catalyst loading reduced surface D-atom concentrations and reduced saturated alcohol formation (e.g., via reduced H-addition to surface alkyl radicals). Third, for CUS processing the ketone selectivities for experiments employing water compared to D2O indicated that 3B2OL were twice as large, whereas for 14PD3OL they were comparable. This suggests, somewhat surprisingly, that for 3B2OL enol tautomerization to ketone is a slow, and possibly rate-controlling, process. Finally, again for CUS processing, the similarity in ketone selectivities (all ~17%) for H2 compared to D2 hydrogenation for both 3B2OL and 14PD3OL suggest that both H/D isotopes have rapid surface diffusion and hence give rise to nearly equal selectivies. Restated, the thermal or cavitating ultrasound activation is much greater than the surface H/D diffusion barrier.

Boyles, Kelly R.; Chajkowski, Sarah M.; Disselkamp, Robert S.; Peden, Charles HF

2006-05-24

52

Photocatalytic and Antibacterial Activity of Titanium, Fluorine and Silver Co-Substituted Hydroxyapatite  

NASA Astrophysics Data System (ADS)

Synthetic hydroxyapatite (HA), an analogue of the mineral component of bone tissue has been widely used in medicine as bone replacing material. To impart specific properties, HA can be chemically modified by anionic and cationic substitutions during synthesis. Thus the present study was focused in synthesizing nanocrystalline Ti, Ag and F co-substituted HA by microwave synthesis. The prepared powders were characterized by XRD and FTIR for their crystal size, cystallinity and functional groups respectively. XRD spectra reveal that crystal size of prepared powders was in the range of 21-25 nm in as synthesized condition and 45-51 nm in 900 ?C heat-treated condition. Complete decomposition of HA to tri calcium phosphate was observed for Ti substituted HA powder after heat-treatment. Addition of F improved the thermal stability of Ti substituted HA as indicated by predominant phase of HA after heat-treatment. The photocatalytic activity of co-substituted HA powders was examined by degradation of methylene blue (5 × 10-5 M concentration) under visible light irradiation and the results were compared with pure HA. The degradation efficiency of co-substituted HA with respect to methylene blue was twice as high as that of pure HA. Ti and Ag has improved the visible light photocatalytic activity of HA, further F co-substitution has not affected the photocatalytic activity of substituted HA. The antibacterial effect of prepared powders was observed against 1 × 105 cells/mL of Escherichia coli using spread plate method at 24 h incubation period. Ag co-substituted HA showed complete inhibition of growth of Escherichia coli. Thus, among Ti, Ti-F, Ti-F-Ag substituted HA powders, Ti-F-Ag co-substituted HA with excellent visible light photocatalytic activity and anti-bacterial property is expected to be a potential candidate for biomedical applications.

Sandhyarani, M.; Rameshbabu, N.; Venkateswarlu, K.; Ravisankar, K. V.; Ashok, M.; Anandan, S.

53

Extrudable Reactive Powder Concretes Hydration, shrinkage and transfer properties  

E-print Network

of a partial substitution of silica fume with crushed quartz on the RPC properties. The cost fines mineral particles (Portland cement, crushed filler, silica fume, fine sand) in the range of 0Extrudable Reactive Powder Concretes Hydration, shrinkage and transfer properties Pierre Mounanga1

Boyer, Edmond

54

Morphology and composition of Ni-Co electrodeposited powders  

SciTech Connect

The morphology, phase and chemical composition of Ni-Co alloy powders electrodeposited from an ammonium sulfate-boric acid containing electrolyte with different ratio of Ni/Co ions were investigated. The ratios of Ni/Co ions were 1/1, 1/2 and 1/3. The morphology, chemical composition and phase composition of the electrodeposited alloy powders were investigated using AES, SEM, EDS and XRD analysis. Composition of the electrolyte, i.e. the ratio of Ni/Co concentrations was found to influence both, the alloy phase composition and the morphology of Ni-Co alloy powders. At the highest ratio of Ni/Co = 1/1 concentrations typical 2D fern-like dendritic particles were obtained. With a decrease of Ni/Co ions ratio among 2D fern-like dendrites, 3D dendrites and different agglomerates were obtained. X-ray diffraction studies showed that the alloy powders mainly consisted of the face-centered cubic {alpha}-nickel phase and hexagonal close-packed {epsilon}-cobalt phase and minor proportions of face-centered cubic {alpha}-cobalt phase. The occurrence of the latter phase was observed only in the alloy powder with the higher cobalt concentration in electrolyte. The electrodeposition of Ni-Co powders occurred in an anomalous manner. - Highlights: Black-Right-Pointing-Pointer Ni-Co alloys powders were successfully electrodeposited. Black-Right-Pointing-Pointer Composition of the electrolyte (Ni/Co ions ratio) was found to influence on morphology of powders. Black-Right-Pointing-Pointer The electrodeposition of Ni-Co powders occurred in an anomalous manner.

Maksimovic, V.M., E-mail: vesnam@vinca.rs [Institute of Nuclear Sciences, 'Vinca', University of Belgrade, 11001 Belgrade, P. O. Box 522 (Serbia); Lacnjevac, U.C. [Institute for Multidisciplinary research, University of Belgrade, P.O. Box 33, 11030 Belgrade (Serbia); Stoiljkovic, M.M. [Institute of Nuclear Sciences, 'Vinca', University of Belgrade, 11001 Belgrade, P. O. Box 522 (Serbia); Pavlovic, M.G. [Institute of Electrochemistry, ICTM, University of Belgrade, 11000 Belgrade, Njegoseva 12 (Serbia); Jovic, V.D. [Institute for Multidisciplinary research, University of Belgrade, P.O. Box 33, 11030 Belgrade (Serbia)

2011-12-15

55

Ceramic powder compaction  

SciTech Connect

With the objective of developing a predictive model for ceramic powder compaction we have investigated methods for characterizing density gradients in ceramic powder compacts, reviewed and compared existing compaction models, conducted compaction experiments on a spray dried alumina powder, and conducted mechanical tests and compaction experiments on model granular materials. Die filling and particle packing, and the behavior of individual granules play an important role in determining compaction behavior and should be incorporated into realistic compaction models. These results support the use of discrete element modeling techniques and statistical mechanics principals to develop a comprehensive model for compaction, something that should be achievable with computers with parallel processing capabilities.

Glass, S.J.; Ewsuk, K.G. [Sandia National Labs., Albuquerque, NM (United States); Mahoney, F.M. [Norton Co., Worcester, MA (United States)

1995-12-31

56

Black Eye  

MedlinePLUS

... Eye Health News Consumer Alerts What Is a Black Eye? Tweet Black eye is a phrase used to describe bruising ... dark bruising in the tissue. What Is a Black Eye? Black Eye Symptoms What Causes a Black ...

57

Introduction Explicit Substitutions  

E-print Network

for implementing proof assistants and programming languages. F.L.C. de Moura Matching via Explicit Substitutions are to be implemented in the level of the language itself. F.L.C. de Moura Matching via Explicit Substitutions #12 are to be implemented in the level of the language itself. Explicit substitutions provide an adequate framework, closer

Ayala-Rincón, Mauricio

58

[Otologic diagnosis: powder technique].  

PubMed

The otologic diagnostic powder test with grape - sugar simple will be performed with a powder - blower. It permits a good differentiation between dry squamous epithelium and wet mucosa. In our opinion this test therefore is unrenouncable in microscopic differentiation between mucosa in central perforations on one hand and atrophic scars, retraction pockets or adhesive epithelium of the drum or complete atelectasis of the tympanic cavity on the other hand. PMID:21626473

Tolsdorff, P

2011-06-01

59

Shear consolidation of powders  

NASA Astrophysics Data System (ADS)

The manufacture of bulk parts from metastable powder materials requires new approaches to cold consolidation. One potential technique is equal-channel angular extrusion (ECAE), a simple shear process. This thesis describes an investigation into the effects of confining pressure (back-pressure) on single-pass, right-angled ECAE consolidation of copper and aluminum 6061 powders below 250°C, using an extrusion machine designed and constructed for this purpose. Empirical relationships for punch pressure requirements as a function of back-pressure and billet length are determined experimentally and compared with published theory. Powder particle boundaries are examined in extruded billets, revealing pores and regions of localized shear formed under low back-pressure conditions. This shear localization is considered with a visualization experiment involving wax spheres in a transparent die, and a linear stability analysis of simple shear of a thin strip of material described by a generalized powder yield function and flow rule. The back-pressures required to obtain homogeneous, pore-free microstructures are determined, and related to the response of the powders during the initial compaction stage of ECAE. Interparticle bond formation in cold powder processing is briefly discussed in the context of multi-pass extrusions.

Hanna, James A.

60

Stable powders made from photosensitive polycrystalline complexes of heterocyclic monomers and their polymers  

NASA Technical Reports Server (NTRS)

The present invention relates to a low electronic conductivity polymer composition having well dispersed metal granules, a stable powder made from photosensitive polycrystalline complexes of pyrrole, or its substituted derivatives and silver cations for making the polymer composition, and methods of forming the stable powder and polymer composition, respectively. A polycrystalline complex of silver and a monomer, such as pyrrole, its substituted derivatives or combinations thereof, is precipitated in the form of a stable photosensitive powder upon addition of the monomer to a solvent solution, such as toluene containing an electron acceptor. The photosensitive powder can be stored in the dark until needed. The powder may be dissolved in a solvent, cast onto a substrate and photopolymerized.

Hodko, Dalibor (Inventor); Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

1999-01-01

61

Fabricating solid carbon porous electrodes from powders  

DOEpatents

Fabrication of conductive solid porous carbon electrodes for use in batteries, double layer capacitors, fuel cells, capacitive dionization, and waste treatment. Electrodes fabricated from low surface area (<50 m.sup.2 /gm) graphite and cokes exhibit excellent reversible lithium intercalation characteristics, making them ideal for use as anodes in high voltage lithium insertion (lithium-ion) batteries. Electrodes having a higher surface area, fabricated from powdered carbon blacks, such as carbon aerogel powder, carbon aerogel microspheres, activated carbons, etc. yield high conductivity carbon compositives with excellent double layer capacity, and can be used in double layer capacitors, or for capacitive deionization and/or waste treatment of liquid streams. By adding metallic catalysts to be high surface area carbons, fuel cell electrodes can be produced.

Kaschmitter, James L. (Pleasanton, CA); Tran, Tri D. (Livermore, CA); Feikert, John H. (Livermore, CA); Mayer, Steven T. (San Leandro, CA)

1997-01-01

62

Fabricating solid carbon porous electrodes from powders  

DOEpatents

Fabrication is described for conductive solid porous carbon electrodes for use in batteries, double layer capacitors, fuel cells, capacitive deionization, and waste treatment. Electrodes fabricated from low surface area (<50 m{sup 2}/gm) graphite and cokes exhibit excellent reversible lithium intercalation characteristics, making them ideal for use as anodes in high voltage lithium insertion (lithium-ion) batteries. Electrodes having a higher surface area, fabricated from powdered carbon blacks, such as carbon aerogel powder, carbon aerogel microspheres, activated carbons, etc. yield high conductivity carbon composites with excellent double layer capacity, and can be used in double layer capacitors, or for capacitive deionization and/or waste treatment of liquid streams. By adding metallic catalysts to high surface area carbons, fuel cell electrodes can be produced. 1 fig.

Kaschmitter, J.L.; Tran, T.D.; Feikert, J.H.; Mayer, S.T.

1997-06-10

63

Ultrafine hydrogen storage powders  

DOEpatents

A method of making hydrogen storage powder resistant to fracture in service involves forming a melt having the appropriate composition for the hydrogen storage material, such, for example, LaNi.sub.5 and other AB.sub.5 type materials and AB.sub.5+x materials, where x is from about -2.5 to about +2.5, including x=0, and the melt is gas atomized under conditions of melt temperature and atomizing gas pressure to form generally spherical powder particles. The hydrogen storage powder exhibits improved chemcial homogeneity as a result of rapid solidfication from the melt and small particle size that is more resistant to microcracking during hydrogen absorption/desorption cycling. A hydrogen storage component, such as an electrode for a battery or electrochemical fuel cell, made from the gas atomized hydrogen storage material is resistant to hydrogen degradation upon hydrogen absorption/desorption that occurs for example, during charging/discharging of a battery. Such hydrogen storage components can be made by consolidating and optionally sintering the gas atomized hydrogen storage powder or alternately by shaping the gas atomized powder and a suitable binder to a desired configuration in a mold or die.

Anderson, Iver E. (Ames, IA); Ellis, Timothy W. (Doylestown, PA); Pecharsky, Vitalij K. (Ames, IA); Ting, Jason (Ames, IA); Terpstra, Robert (Ames, IA); Bowman, Robert C. (La Mesa, CA); Witham, Charles K. (Pasadena, CA); Fultz, Brent T. (Pasadena, CA); Bugga, Ratnakumar V. (Arcadia, CA)

2000-06-13

64

Dissolution properties of piroxicam powders and capsules as a function of particle size and the agglomeration of powders.  

PubMed

The poor dissolution characteristics of relatively insoluble drugs have long been a problem to the pharmaceutical industry. An example is piroxicam, a highly potent anti-inflammatory agent. In many countries, a large number of generic piroxicam products are available to the prescriber. The aim of this study was to investigate the cause of the dissolution problems experienced by manufacturers of generic piroxicam capsules. Two raw material batches and the dissolution properties of several piroxicam capsules were studied. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) results showed that the two raw material samples were identical with respect to polymorphic modification. The particles of powder 1 were smaller than those of powder 2, but the dissolution of powder 1 was much slower than that of powder 2. The dissolution results for the capsules showed a marked difference among different brands, with capsule C not meeting the USP tolerance. Adding surfactant to the dissolution medium increased the dissolution of both powder 1 and capsule C. Failure of powder 1 or capsule C to meet USP dissolution criteria could result in differences in product efficacy, as well as in potential side effects. Such observations should be taken into account along with other relevant considerations when decisions regarding the generic substitution of oral piroxicam products are made. PMID:11028221

Swanepoel, E; Liebenberg, W; de Villiers, M M; Dekker, T G

2000-10-01

65

Partial substitution of Mo{sup 6+} by S{sup 6+} in the fast oxide ion conductor La{sub 2}Mo{sub 2}O{sub 9}: Synthesis, structure and sulfur depletion  

SciTech Connect

Powder-solid state reaction route using La{sub 2}(SO{sub 4}){sub 3} as sulfur source was used to prepare compositions of the solid solution La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9}. Single phases were only obtained in the substitution range extending up to y=0.8 (40 mol% S) at the annealing temperature of 850 Degree-Sign C with regard to the limit of stability of the lanthanum sulphate reactant. Within the synthesis conditions, a stabilization of the high temperature {beta}-form is observed from and above y=0.1 (5 mol% S). Temperature-controlled X-ray diffraction and thermogravimetric analyses have shown that La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders undergo thermal decompositions in two steps. Heating above 900 Degree-Sign C, a sulfur depletion to the benefit of molybdenum in La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders leads to the formation of La{sub 2}SO{sub 6}. At higher temperature, the exsolved La{sub 2}SO{sub 6} phase then decomposes into La{sub 2}O{sub 3}, which in turn reacts with the sulfur-depleted La{sub 2}Mo{sub 2}O{sub 9} phase to form La{sub 2}MoO{sub 6}. The present study also reveals that depending on the substitution rate y, the sulfur depletion can be induced by ball-milling of raw powders. Along the La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} series, the isovalent substitution of molybdenum by sulfur tends to restrict in magnitude, or even to suppress above 400 Degree-Sign C, the distortive thermal expansion of the cubic {beta}-type structure, thus strongly decreasing the conductance at high temperature. - Graphical abstract: La{sub 2}O{sub 3}-MoO{sub 3}-'SO{sub 3}' ternary phase diagram showing the exsolution path at low temperature (white arrows) and the total decomposition path at high temperature (black arrows) of {beta}-La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders. Highlights: Black-Right-Pointing-Pointer Isovalent substitution of molybdenum by sulfur in La{sub 2}Mo{sub 2}O{sub 9} up to 40 mol%. Black-Right-Pointing-Pointer Stabilization of the {beta}-form for a sulfur content greater than or equal to 5 mol%. Black-Right-Pointing-Pointer Decomposition by sulfur exsolution induced by thermal treatment or ball-milling. Black-Right-Pointing-Pointer Reduction or even cancellation of the distortive thermal expansion above 400 Degree-Sign C. Black-Right-Pointing-Pointer Decrease of conductance at high T involved by the low thermal expansion above 400 Degree-Sign C.

Mhadhbi, Noureddine [LUNAM Universite, Universite du Maine, CNRS UMR 6283, Institut des Molecules et des Materiaux du Mans, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France); Corbel, Gwenaeel, E-mail: gwenael.corbel@univ-lemans.fr [LUNAM Universite, Universite du Maine, CNRS UMR 6283, Institut des Molecules et des Materiaux du Mans, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France); Lacorre, Philippe; Bulou, Alain [LUNAM Universite, Universite du Maine, CNRS UMR 6283, Institut des Molecules et des Materiaux du Mans, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France)

2012-06-15

66

Iowa Powder Atomization Technologies  

SciTech Connect

The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

None

2012-01-01

67

Si-substituted hydroxyapatite nanopowders: Synthesis, thermal stability and sinterability  

SciTech Connect

Synthetic hydroxyapatites incorporating small amounts of Si have shown improved biological performances in terms of enhanced bone apposition, bone in-growth and cell-mediated degradation. This paper reports a systematic investigation on Si-substituted hydroxyapatite (Si 1.40 wt%) nanopowders produced following two different conventional wet methodologies: (a) precipitation of Ca(NO{sub 3}){sub 2}.4H{sub 2}O and (b) titration of Ca(OH){sub 2}. The influence of the synthesis process on composition, thermal behaviour and sinterability of the resulting nanopowders is studied. Samples were characterised by electron microscopy, induced coupled plasma atomic emission spectroscopy, thermal analysis, infrared spectroscopy, N{sub 2} adsorption measurements, X-ray diffraction and dilatometry. Semicrystalline Si-substituted hydroxyapatite powders made up of needle-like nanoparticles were obtained, the specific surface area ranged between 84 and 110 m{sup 2}/g. Pure and Si-substituted hydroxyapatite nanopowders derived from Ca(NO{sub 3}){sub 2}.4H{sub 2}O decomposed around 1000 deg. C. Si-substituted hydroxyapatite nanopowders obtained from Ca(OH){sub 2} were thermally stable up to 1200 deg. C and showed a distinct decreased thermal stability with respect to the homologous pure sample. Si-substituted hydroxyapatites exhibited higher sintering temperature and increased total shrinkage with respect to pure powders. Nanostructured dense ceramics were obtained by sintering at 1100 deg. C Si-substituted hydroxyapatites derived from Ca(OH){sub 2}.

Bianco, Alessandra [University of Rome Tor Vergata, Department of Chemical Sciences and Technologies, INSTM Research Unit Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy)], E-mail: bianco@stc.uniroma2.it; Cacciotti, Ilaria [University of Rome Tor Vergata, Department of Chemical Sciences and Technologies, INSTM Research Unit Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Lombardi, Mariangela [Politecnico of Torino, Department of Materials Science and Chemical Engineering, INSTM Research Unit Politecnico di Torino: LINCE Lab, Corso Duca degli Abruzzi, 24-10129 Torino (Italy)], E-mail: mariangela.lombardi@polito.it; Montanaro, Laura [Politecnico of Torino, Department of Materials Science and Chemical Engineering, INSTM Research Unit Politecnico di Torino: LINCE Lab, Corso Duca degli Abruzzi, 24-10129 Torino (Italy)

2009-02-04

68

Spiral Powder Overlays  

E-print Network

Whether you encounter electron powder diffraction patterns everyday, or run across them only rarely, interpreting them may require a bit of preparation. But it's easy to lose track of the numbers for your microscope's camera constant, not to mention the bewildering array of lattice parameters and symmetries that one may encounter in the microscope. In that context, we describe

P. Fraundorf; Shuhan Lin

69

Laser powder deposition  

Microsoft Academic Search

Purpose – The purpose of this paper is to review the state of the art of laser powder deposition (LPD), a solid freeform fabrication technique capable of fabricating fully dense functional items from a wide range of common engineering materials, such as aluminum alloys, steels, titanium alloys, nickel superalloys and refractory materials. Design\\/methodology\\/approach – The main R&D efforts and the

Lino Costa; Rui Vilar

2009-01-01

70

Sintering of Tin Powder  

Microsoft Academic Search

MOST powdered metals will sinter together appreciably when heated to a temperature which, in the absence of extraneous factors, is about three-quarters of their absolute melting point; metals of low melting point tend to be exceptions, however, to this generalization in that they can be heated nearly to their melting point before sintering takes place. There is no evidence, in

R. F. Smart; E. C. Ellwood

1958-01-01

71

Dielectric Constant of Powders  

Microsoft Academic Search

MEASUREMENTS have been made at 9,200 Mc\\/s to determine the dependence of dielectric constant of powder samples' packing densities. The net polarization P produced in a substance in an electric field consists of the contributions of electronic, atomic and dipolar polarizations. It is related to the dielectric constant by Clausius-Masotti relation: where K = (? - l)\\/(? + 2), M

Prem Swarup; R. P. Arora

1964-01-01

72

Demystifying Mystery Powders.  

ERIC Educational Resources Information Center

Describes science activities which use simple chemical tests to distinguish between materials and to determine some of their properties. Explains the water, iodine, heat, acid, baking soda, acid/base indicator, glucose, and sugar tests. Includes activities to enhance chemical testing and a list of suggested powders for use. (RT)

Kotar, Michael

1989-01-01

73

Synthesis, stoichiometry and thermal stability of Zn 3N 2 powders prepared by ammonolysis reactions  

NASA Astrophysics Data System (ADS)

Zn 3N 2 powders were prepared by ammonolysis reactions at 600 °C and examined by thermogravimetric analysis, powder X-ray and neutron diffraction. The powders obtained in this way are unstable in an oxygen atmosphere above 450 °C. In an argon atmosphere, the powders are stable up to their decomposition point at around 700 °C. Structural models obtained from Rietveld refinements against the powder neutron diffraction data indicate that the Zn 3N 2 powders so-prepared have the anti-bixbyite structure and are almost certainly stoichiometric with no compelling evidence of nitrogen vacancies. Further, no evidence was found for aliovalent oxygen substitution at the nitrogen sites. The calculated bond valence sums imply that Zn 3N 2 cannot be described as a 100% ionic compound. The structural findings are supported by photoluminescence measurements that reveal a band gap of approximately 0.9 eV.

Paniconi, Giordano; Stoeva, Zlatka; Smith, Ronald I.; Dippo, Patricia C.; Gallagher, Bryan L.; Gregory, Duncan H.

2008-01-01

74

Method to blend separator powders  

DOEpatents

A method for making a blended powder mixture, whereby two or more powders are mixed in a container with a liquid selected from nitrogen or short-chain alcohols, where at least one of the powders has an angle of repose greater than approximately 50 degrees. The method is useful in preparing blended powders of Li halides and MgO for use in the preparation of thermal battery separators.

Guidotti, Ronald A. (Albuquerque, NM); Andazola, Arthur H. (Albuquerque, NM); Reinhardt, Frederick W. (Albuquerque, NM)

2007-12-04

75

Powdering or spraying.  

PubMed

Application--especially in combination with the new camera--is so easy and advantageous that it has advanced to become the standard procedure in our practice. Potential for improvement still exists in the stiffness of the cannula, in a release mechanism located separately from the cannula and in the impudent demand to completely do away with powder and spray. Despite announcements to the contrary by alternative systems, the fulfilment of this desire appears to be a long way off. PMID:19213361

Reiss, B

2009-01-01

76

Preparation of superconductor precursor powders  

DOEpatents

A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

Bhattacharya, Raghunath (Littleton, CO)

1998-01-01

77

40 CFR 721.981 - Substituted naphtholoazo-substituted naphthalenyl-substituted azonaphthol chromium complex.  

Code of Federal Regulations, 2010 CFR

...naphthalenyl-substituted azonaphthol chromium complex. 721.981 Section 721...naphthalenyl-substituted azonaphthol chromium complex. (a) Chemical substance...naphthalenyl-substituted azonaphthol chromium complex (PMN P-93-1631) is...

2010-07-01

78

Black Cohosh  

MedlinePLUS

... mothers. Black cohosh should not be confused with blue cohosh (Caulophyllum thalictroides), which has different properties, treatment ... black cohosh. Black cohosh is sometimes used with blue cohosh to stimulate labor, but this therapy has ...

79

Black Funnels  

E-print Network

The Hartle-Hawking state of $\\mathcal{N}=4$ SYM at strong coupling and large $N$ on a fixed black hole background has two proposed gravitational duals: a black funnel or a black droplet. We construct the black funnel solutions that are dual to the Hartle-Hawking state on a Schwarzschild black hole and on a class of three-dimensional asymptotically flat black hole backgrounds. We compute their holographic stress tensor and argue for the stability of these solutions.

Jorge E. Santos; Benson Way

2012-08-30

80

Synthesis of fine PbE (E = S, Se) powder from direct in situ reduction of sulphur or selenium  

Microsoft Academic Search

Lead sulphide and lead selenide have been prepared for the first time, by in situ reduction of elemental S or Se by using aqueous DMF or aqueous SFS as reducing agents and their reaction with lead acetate. The grayish-black powder has been characterized by powder XRD measurement, XPS and SEM\\/EDAX analysis. Powder X-ray diffraction pattern revealed that cubic PbE (E=S,

P. K. Khanna; V. V. V. S. Subbarao; M. Wagh; P. Jadhav; K. R. Patil

2005-01-01

81

Sintering of powder mixtures and the growth of ferrous powder metallurgy  

Microsoft Academic Search

Advances in the understanding of sintering of powder mixtures contributed significantly to the growth of ferrous powder metallurgy industry. Solid-state sintering and liquid-phase activated sintering play an important role in the sintering of powder mixtures. In this paper, sintering of iron powder with graphite; iron powder with copper and graphite; iron powder with nickel and graphite; iron powder with phosphorus;

K. S Narasimhan

2001-01-01

82

Reversible mechanochromism and enhanced AIE in tetraphenylethene substituted phenanthroimidazoles.  

PubMed

Tetraphenylethene (TPE) substituted phenanthroimidazoles 3a and 3b were designed and synthesized by the Suzuki cross-coupling reaction. They show reversible mechanochromic behavior with contrast colors between sky-blue and yellow green. The powder XRD studies show that destruction of a crystalline state into an amorphous state is responsible for mechanochromism. Hydrogen bonding interaction of a cyano-group in 3b results in enhanced AIE and improved thermal stability. PMID:24983656

Misra, Rajneesh; Jadhav, Thaksen; Dhokale, Bhausaheb; Mobin, Shaikh M

2014-08-21

83

The substitutability of reinforcers  

PubMed Central

Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included. PMID:16812696

Green, Leonard; Freed, Debra E.

1993-01-01

84

Polymer powder prepregging: Scoping study  

NASA Technical Reports Server (NTRS)

Early on, it was found that NEAT LARC-TPI thermoplastic polyimide powder behaved elastoplastically at pressures to 20 ksi and temperatures to 260 degrees celcius (below MP). At high resin assay, resin powder could be continuously cold-flowed around individual carbon fibers in a metal rolling mill. At low resin assay (2:1, C:TPI), fiber breakage was prohibitive. Thus, although processing of TPI below MP would be quite unique, it appears that the polymer must be melted and flowed to produce low resin assay prepreg. Fiber tow was spread to 75 mm using a venturi slot tunnel. This allowed intimate powder/fiber interaction. Two techniques were examined for getting room temperature powder onto the room temperature fiber surface. Electrostatic powder coating allows the charged powder to cling tenaciously to the fiber, even while heated with a hot air gun to above its melt temperature. A variant of the wet slurry coating process was also explored. The carbon fibers are first wetted with water. Then dry powder is sprinkled onto the wet tow and doctor-rolled between the fibers. The wet structure is then taken onto a heated roll, with hot air guns drying and sinter-melting the powder onto the fiber surfaces. In both cases SEM shows individual fibers coated with powder particles that have melted in place and flowed along the fiber surface via surface tension.

Throne, James L.

1988-01-01

85

40 CFR 721.9545 - Substituted phenyl azo substituted sulfocarbopolycle, sodium salt.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Substituted phenyl azo substituted sulfocarbopolycle, sodium...Substances § 721.9545 Substituted phenyl azo substituted sulfocarbopolycle, sodium...identified generically as a substituted phenyl azo substituted...

2010-07-01

86

Black holes  

PubMed Central

Recent progress in black hole research is illustrated by three examples. We discuss the observational challenges that were met to show that a supermassive black hole exists at the center of our galaxy. Stellar-size black holes have been studied in x-ray binaries and microquasars. Finally, numerical simulations have become possible for the merger of black hole binaries. PMID:11553801

Brugmann, B.; Ghez, A. M.; Greiner, J.

2001-01-01

87

Characterization of mutagenic activity in grain-based coffee-substitute blends and instant coffees  

SciTech Connect

Several grain-based coffee-substitute blends and instant coffees showed a mutagenic response in the Ames/Salmonella test using TA98, YG1024 and YG1O29 with metabolic activation. The beverage powders contained 150 to 500 TA98 and 1150 to 4050 YG1024 revertant colonies/gram, respectively. The mutagenic activity in the beverage powders was shown to be stable to heat and the products varied in resistance to acid nitrite treatment. Characterization of the mutagenic activity, using HPLC-and the Ames test of the collected fractions, showed the coffee-substitutes and instant coffees contain several mutagenic compounds, which are most likely aromatic amines.

Johansson, M.A.E.; Knize, M.G.; Felton, J.S.; Jagerstad, M.

1994-06-01

88

Ultrafast Powder Diffraction  

NASA Astrophysics Data System (ADS)

An overview is given of the use of powder synchrotron-X-ray and neutron diffraction to study very fast physical or chemical processes that require time resolution of 500 ms or less. The experimental requirements to obtain data of good quality are considered, including the incident flux, detector characteristics, and the different strategies possible for irreversible and reversible processes. The latter are accessible via a stroboscopic approach whereas the former require the maximum rates of data acquisition. Some recent studies are described, drawn from the areas of combustion synthesis, metallurgy and catalysis. The exploitation of the bunch structure of a synchrotron ring to obtain time resolution in the sub-ns range with the pump-probe stroboscopic approach is also illustrated.

Fitch, Andy; Curfs, Caroline

89

40 CFR Appendix O to Subpart G of... - Substitutes Listed in the September 27, 2006 Final Rule, Effective November 27, 2006  

Code of Federal Regulations, 2012 CFR

...Explosion Protection Sector—Total Flooding Substitutes—Acceptable Subject to Use...Conditions Further information Total flooding Gelled Halocarbon/Dry Chemical Suspension...additional comments 1, 2, 3, 4, 5 Total flooding Powdered Aerosol D (Aero-K®...

2012-07-01

90

40 CFR Appendix O to Subpart G of... - Substitutes Listed in the September 27, 2006 Final Rule, Effective November 27, 2006  

Code of Federal Regulations, 2010 CFR

...Explosion Protection Sector—Total Flooding Substitutes—Acceptable Subject to Use...Conditions Further information Total flooding Gelled Halocarbon/Dry Chemical Suspension...additional comments 1, 2, 3, 4, 5 Total flooding Powdered Aerosol D (Aero-K®...

2010-07-01

91

40 CFR Appendix O to Subpart G of... - Substitutes Listed in the September 27, 2006 Final Rule, Effective November 27, 2006  

Code of Federal Regulations, 2013 CFR

...Explosion Protection Sector—Total Flooding Substitutes—Acceptable Subject to Use...Conditions Further information Total flooding Gelled Halocarbon/Dry Chemical Suspension...additional comments 1, 2, 3, 4, 5 Total flooding Powdered Aerosol D (Aero-K ®,...

2013-07-01

92

40 CFR Appendix O to Subpart G of... - Substitutes Listed in the September 27, 2006 Final Rule, Effective November 27, 2006  

Code of Federal Regulations, 2011 CFR

...Explosion Protection Sector—Total Flooding Substitutes—Acceptable Subject to Use...Conditions Further information Total flooding Gelled Halocarbon/Dry Chemical Suspension...additional comments 1, 2, 3, 4, 5 Total flooding Powdered Aerosol D (Aero-K®...

2011-07-01

93

Baking powder pica mimicking preeclampsia.  

PubMed

We report a case of baking powder pica during pregnancy that was associated with maternal hypertension, hypokalemia, and elevated liver function tests. After discontinuation of baking powder ingestion and correction of electrolyte abnormalities, the blood pressure and the liver function tests normalized. PMID:1442966

Barton, J R; Riely, C A; Sibai, B M

1992-07-01

94

Powdered resin for condensate polishing  

Microsoft Academic Search

Powdered resin systems have a lot to offer in the deionization of low TDS waters, as can be seen in the wide use of this process for the treatment of condensate in the electric power industry. I believe that as new ion-exchange resins are developed, we will see the powdered ion-exchange resin process adopted in other industries. At this time,

Richard Hetherington

1997-01-01

95

Black Holes  

NASA Astrophysics Data System (ADS)

Participants; Preface Mario Livio and Anton Koekemoer; 1. Black holes, entropy, and information G. T. Horowitz; 2. Gravitational waves from black-hole mergers J. G. Baker, W. D. Boggs, J. M. Centrella, B. J. Kelley, S. T. McWilliams and J. R. van Meter; 3. Out-of-this-world physics: black holes at future colliders G. Landsberg; 4. Black holes in globular clusters S. L. W. McMillan; 5. Evolution of massive black holes M. Volonteri; 6. Supermassive black holes in deep multiwavelength surveys C. M. Urry and E. Treister; 7. Black-hole masses from reverberation mapping B. M. Peterson and M. C. Bentz; 8. Black-hole masses from gas dynamics F. D. Macchetto; 9. Evolution of supermassive black holes A. Müller and G. Hasinger; 10. Black-hole masses of distant quasars M. Vestergaard; 11. The accretion history of supermassive black holes K. Brand and the NDWFS Boötes Survey Teams; 12. Strong field gravity and spin of black holes from broad iron lines A. C. Fabian; 13. Birth of massive black-hole binaries M. Colpi, M. Dotti, L. Mayer and S. Kazantzidis; 14. Dynamics around supermassive black holes A. Gualandris and D. Merritt; 15. Black-hole formation and growth: simulations in general relativity S. L. Shapiro; 16. Estimating the spins of stellar-mass black holes J. E. McClintock, R. Narayan and R. Shafee; 17. Stellar relaxation processes near the Galactic massive black hole T. Alexander; 18. Tidal disruptions of stars by supermassive black holes S. Gezari; 19. Where to look for radiatively inefficient accretion flows in low-luminosity AGN M. Chiaberge; 20. Making black holes visible: accretion, radiation, and jets J. H. Krolik.

Livio, Mario; Koekemoer, Anton M.

2011-02-01

96

EFFICIENT ATTACKS ON HOMOPHONIC SUBSTITUTION CIPHERS  

Microsoft Academic Search

Substitution ciphers are one of the earliest types of ciphers. Examples of classic substitution ciphers include the well-known simple substitution and the less well-known homophonic substitution. Although simple substitution ciphers are indeed simple - both in terms of their use and attacks; the homophonic substitution ciphers are far more challenging to break. Even with modern computing technology, homophonic substitution ciphers

Amrapali Dhavare

2011-01-01

97

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum powder. 73.2645 Section 73...CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in...

2012-04-01

98

21 CFR 73.1645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum powder. 73.1645 Section 73.1645...CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely...

2012-04-01

99

Black droplets  

NASA Astrophysics Data System (ADS)

Black droplets and black funnels are gravitational duals to states of a large N, strongly coupled CFT on a fixed black hole background. We numerically construct black droplets corresponding to a CFT on a Schwarzchild background with finite asymptotic temperature. We find two branches of such droplet solutions which meet at a turning point. Our results suggest that the equilibrium black droplet solution does not exist, which would imply that the Hartle-Hawking state in this system is dual to the black funnel constructed in [1]. We also compute the holographic stress energy tensor and match its asymptotic behaviour to perturbation theory.

Santos, Jorge E.; Way, Benson

2014-08-01

100

Effects of the carbon powder characteristics in the cathode gas diffusion layer on the performance of polymer electrolyte fuel cells  

NASA Astrophysics Data System (ADS)

The effects of two different carbon powders (oil-furnace carbon black and acetylene-black) as materials for carbon cloth-based cathode gas diffusion layers on the performance of polymer electrolyte fuel cell (PEFC) electrodes were investigated. The carbon powder characteristics affect the reversible potential of the cell ( E°) and both the linear and non-linear polarization components. The best fuel cell performance was obtained at an oxygen pressure of 5 atm with acetylene-black in the cathode gas diffusion layer.

Antolini, E.; Passos, R. R.; Ticianelli, E. A.

101

Exfoliation and thermal transformations of Nb-substituted layered titanates  

SciTech Connect

Single-layer Nb-substituted titanate nanosheets of ca. 1 nm thickness were obtained by exfoliating tetrabutylammonium (TBA)-intercalated Nb-substituted titanates in water. AFM images and turbidity measurements reveal that the exfoliated nanosheets crack and corrugate when sonicated. Upon heating, the thermal transformation into anatase and further to rutile is retarded. This suppression of the phase transition upon higher valent substitution may promote technological applications of anatase thin films, hereunder development of films with TCO properties. Depending on the oxygen partial pressure during the transformation, the Nb-substitution into TiO{sub 2} provokes different defect situations and also electronic properties. At reducing conditions, Nb is incorporated as Nb{sup V} and an equivalent amount of Ti{sup IV} is transformed to Ti{sup III} as evidenced by XPS. Magnetic susceptibility data show accordingly paramagnetic behavior. For samples heated in air Ti{sup IV} and Nb{sup V} cations prevail, the latter is compensated by cation vacancies. {sup 93}Nb MAS NMR data prove that Nb is finely dispersed into the transformed (Ti,Nb)O{sub 2} oxide matrices without sign of Nb{sub 2}O{sub 5} (nano)precipitates. The Nb-O-Ti bonds and defects at cation sites are considered key factors for increasing the transformation temperatures for conversion of the nanosheets to anatase and finally into rutile. It is further tempting to link the delay in crystallization to morphology limitations originating from the nanosheets. The present work shows that layered Nb-titanates are appropriate precursors for formation of highly oriented Nb-substituted anatase thin films via delamination, reconstruction and subsequent heat treatment. - Graphical abstract: Layered Nb-titanates are appropriate precursors for formation of highly oriented Nb-substituted anatase thin films via delamination, reconstruction and subsequent heat treatment. Highlights: Black-Right-Pointing-Pointer Single layer Nb-substituted nanosheets were obtained by exfoliation of layered titanates. Black-Right-Pointing-Pointer Nb(V) successfully introduced into anatase and rutile solid solutions. Black-Right-Pointing-Pointer Anatase obtained from reconstructed nanosheets exhibit enhanced thermal stability. Black-Right-Pointing-Pointer Oxygen partial pressure influences the valence of Nb in heat-treated samples. Black-Right-Pointing-Pointer Deposition of oriented thin Ti(Nb)O{sub 2} layers by spray coating was demonstrated.

Song Haiyan; Sjastad, Anja O.; Fjellvag, Helmer; Okamoto, Hiroshi [Department of Chemistry and Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo (Norway); Vistad, Ornulv B.; Arstad, Bjornar [SINTEF Materials and Chemistry, P.O. Box 124, Blindern, N-0314 Oslo (Norway); Norby, Poul, E-mail: pnor@risoe.dtu.dk [Department of Chemistry and Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo (Norway); Materials Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, DK-4000 Roskilde (Denmark)

2011-12-15

102

Preparation of superconductor precursor powders  

DOEpatents

A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products. 7 figs.

Bhattacharya, R.

1998-08-04

103

powder in water  

NASA Astrophysics Data System (ADS)

Submicron-sized NiAl2+ X O4 fragments and nanocondensates of Ni-doped ?-Al2O3, Al-doped NiO and ?-Ni(OH)2 were synthesized simultaneously by pulsed laser ablation of NiAl2O4 powder in water and characterized using X-ray/electron diffraction and optical spectroscopy. The NiAl2+ X O4 is Al-enriched spinel with dislocations and subgrains. The Ni-doped ?-Al2O3 spinel has paracrystalline distribution (i.e., with fair constant longitudinal spacing, but variable relative lateral translations) of defect clusters and intimate intergrowth of ?-Al2O3 and 2x(3) commensurate superstructure. The Al-doped NiO has perfect cubo-octahedron shape and as small as 5 nm in size. The ?-Ni(OH)2 and 1-D turbostratic hydroxide lamellae occurred as a matrix of these oxide nanoparticles. The colloidal suspension containing the composite phases has a minimum band gap of 5.3 eV for potential photocatalytic applications.

Chan, Ya-Ting; Wu, Chao-Hsien; Shen, Pouyan; Chen, Shuei-Yuan

2014-09-01

104

Explicit Substitutions and Programming Languages  

Microsoft Academic Search

The ?-calculus has been much used to study the theory of substitution in logical systems and programming languages. However, with explicit substitutions, it is possible to get finer properties with re- spect to gradual implementations of substitutions as effectively done in runtimes of programming languages. But the theory of explicit substi- tutions has some defects such as non-confluence or the

Jean-jacques Lévy; Luc Maranget

1999-01-01

105

Pharmaceutical Powder Diffraction: Structure Solution from PXRD  

E-print Network

Pharmaceutical Powder Diffraction: Structure Solution from PXRD How reliable are our structures? Pharmaceutical Powder Diffraction: Structure Solution from PXRD How reliable are our structures? Maryjane

106

Silica powders for powder evacuated thermal insulating panel and method  

DOEpatents

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2/ g is described. The silica powders are prepared by reacting a tetraakyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders.

Harris, Michael T. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Weaver, Fred J. (Knoxville, TN)

1996-01-01

107

Silica powders for powder evacuated thermal insulating panel and method  

DOEpatents

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2/ g is described. The silica powders are prepared by reacting a tetraakyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders.

Harris, Michael T. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Weaver, Fred J. (Knoxville, TN)

1995-01-01

108

Silica powders for powder evacuated thermal insulating panel and method  

DOEpatents

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2 /g is described. The silica powders are prepared by reacting a tetraakyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders.

Harris, Michael T. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Weaver, Fred J. (Knoxville, TN)

1994-01-01

109

Synthetic bone graft substitutes.  

PubMed

Replacement of extensive local bone loss is a significant clinical challenge. There are a variety of techniques available to the surgeon to manage this problem, each with their own advantages and disadvantages. It is well known that there is morbidity associated with harvesting of autogenous bone graft and limitations in the quantity of bone available. Alternatively allografts have been reported to have a significant incidence of postoperative infection and fracture as well as the potential risk of disease transmission. During the past 30 years a variety of synthetic bone graft substitutes has been developed with the aim to minimize these complications. The benefits of synthetic grafts include availability, sterility and reduced morbidity. The present article examines the relevance of synthetic bone graft substitutes, their mechanical properties and clinical application. PMID:11409021

Moore, W R; Graves, S E; Bain, G I

2001-06-01

110

Shock compaction of molybdenum powder  

NASA Technical Reports Server (NTRS)

Shock recovery experiments which were carried out in the 9 to 12 GPa range on 1.4 distension Mo and appear adequate to compact to full density ( 45 (SIGMA)m) powders were examined. The stress levels, however, are below those calculated to be from 100 to approx. 22 GPa which a frictional heating model predicts are required to consolidate approx. 10 to 50 (SIGMA)m particles. The model predicts that powders that have a distension of m=1.6 shock pressures of 14 to 72 GPa are required to consolidate Mo powders in the 50 to 10 (SIGMA)m range.

Ahrens, T. J.; Kostka, D.; Vreeland, T., Jr.; Schwarz, R. B.; Kasiraj, P.

1983-01-01

111

BLACK ISSUES  

E-print Network

transactions in recent years include Viacom's acquisition of Black Entertainment Television, NBC's purchaseBLACK ISSUES :: Your Portal To Diversity :: ::::::::::::::::::::::::::: http of the Telemundo television network and the Chicago-based Tribune Company's heavy investments in Spanish

Valero-Cuevas, Francisco

112

Silica powders for powder evacuated thermal insulating panel and method  

Microsoft Academic Search

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g\\/cm³ and an external surface area in the range of about 90 to 600 m²\\/g is described. The silica powders are prepared by reacting a tetraalkyl silicate

M. T. Harris; O. A. Basaran; T. G. Kollie; F. J. Weaver

1996-01-01

113

Silica powders for powder evacuated thermal insulating panel and method  

Microsoft Academic Search

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g\\/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2\\/ g is described. The silica powders are prepared by reacting a tetraakyl

Michael T. Harris; Osman A. Basaran; Thomas G. Kollie; Fred J. Weaver

1996-01-01

114

Silica powders for powder evacuated thermal insulating panel and method  

Microsoft Academic Search

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g\\/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2\\/ g is described. The silica powders are prepared by reacting a tetraakyl

Michael T. Harris; Osman A. Basaran; Thomas G. Kollie; Fred J. Weaver

1995-01-01

115

Silica powders for powder evacuated thermal insulating panel and method  

Microsoft Academic Search

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g\\/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2 \\/g is described. The silica powders are prepared by reacting a tetraakyl

Michael T. Harris; Osman A. Basaran; Thomas G. Kollie; Fred J. Weaver

1994-01-01

116

Growth of Large Single Crystals of Black Phosphorus under High Pressure  

Microsoft Academic Search

A large volume high pressure apparatus has made it possible to grow large single crystals of black phosphorus, P. After converting red P powder into black P under a high pressure of 10 kbar at high temperature, a melt of polycrystalline black P has been gradually solidified to bring about the growth of single crystals. Crystal sizes larger than 5×

Shoichi Endo; Yuichi Akahama; Shin-ichi Terada; Shin-ichiro Narita

1982-01-01

117

Structural studies of magnesium nitride fluorides by powder neutron diffraction  

SciTech Connect

Samples of ternary nitride fluorides, Mg{sub 3}NF{sub 3} and Mg{sub 2}NF have been prepared by solid state reaction of Mg{sub 3}N{sub 2} and MgF{sub 2} at 1323-1423 K and investigated by powder X-ray and powder neutron diffraction techniques. Mg{sub 3}NF{sub 3} is cubic (space group: Pm3m) and has a structure related to rock-salt MgO, but with one cation site vacant. Mg{sub 2}NF is tetragonal (space group: I4{sub 1}/amd) and has an anti-LiFeO{sub 2} related structure. Both compounds are essentially ionic and form structures in which nitride and fluoride anions are crystallographically ordered. The nitride fluorides show temperature independent paramagnetic behaviour between 5 and 300 K. - Graphical abstract: Definitive structures of the ternary magnesium nitride fluorides Mg{sub 3}NF{sub 3} and the lower temperature polymorph of Mg{sub 2}NF have been determined from powder neutron diffraction data. The nitride halides are essentially ionic and exhibit weak temperature independent paramagnetic behaviour. Highlights: Black-Right-Pointing-Pointer Definitive structures of Mg{sub 3}NF{sub 3} and Mg{sub 2}NF were determined by neutron diffraction. Black-Right-Pointing-Pointer Nitride and fluoride anions are crystallographically ordered in both structures. Black-Right-Pointing-Pointer Both compounds exhibit weak, temperature independent paramagnetic behaviour. Black-Right-Pointing-Pointer The compounds are essentially ionic with ionicity increasing with F{sup -} content.

Brogan, Michael A. [School of Chemistry, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Hughes, Robert W. [WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Smith, Ronald I. [ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Gregory, Duncan H., E-mail: Duncan.Gregory@glasgow.ac.uk [WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2012-01-15

118

Black Magic  

NSDL National Science Digital Library

Most non-permanent markers use inks that are made of mixtures of colored pigments and water. How does Black Magic work? Why do some black inks separate into many colors on a wet coffee filter? Why does mixing many colors of ink make black?

2010-01-01

119

Rotary powder feed through apparatus  

DOEpatents

A device for increasing the uniformity of solids within a solids fabrication system, such as a direct light fabrication (DLF) system in which gas entrained powders are passed through the focal point of a moving high-power light which fuses the particles in the powder to a surface being built up in layers. The invention provides a feed through interface wherein gas entrained powders input from stationary input lines are coupled to a rotating head of the fabrication system. The invention eliminates the need to provide additional slack in the feed lines to accommodate head rotation, and therefore reduces feed line bending movements which induce non-uniform feeding of gas entrained powder to a rotating head.

Lewis, Gary K. (Los Alamos, NM); Less, Richard M. (Los Alamos, NM)

2001-01-01

120

Ceramic powder for sintering materials  

NASA Technical Reports Server (NTRS)

Surface activity of ceramic powders such as MgO and Al2O3, for use in sintering with sp. emphasis on their particle size, shape, particle size distribution, packing, and coexisting additives and impurities are reviewed.

Akiya, H.; Saito, A.

1984-01-01

121

Controlled release of drugs from CD polymers substituted with ionic groups  

Microsoft Academic Search

Various disinfecting drugs (ethacridine lactate, methylene blue, gentian violet, brilliant green, fuchsin acid, cetylpyridinium chloride) were incorporated into CD bead polymers substituted with carboxymetbyl groups and a retarded release rate was measured. These polymers were successfully used as sustained release wound powders as well as in chewing gum formulations.

É. Fenyvesi; A. Ujházy; J. Szejtli; S. Potter; T. G. Gan

1996-01-01

122

Spectroscopic properties of lanthanoid benzene carboxylates in the solid state: Part 2. Polar substituted benzoates  

Microsoft Academic Search

Europium and terbium complexes of ortho, meta and para substituted benzoate ligands including nitrobenzoate (NBA), aminobenzoate (ABA), hydroxybenzoate (OHBA) and methoxybenzoate (MeOBA) have been synthesised by metathesis reactions, carried out in aqueous media. The complexes were characterised by elemental, compositional and structural investigations, including microanalysis, EDTA titrations, differential thermal analysis, infra red spectroscopy, X-ray powder diffraction and single crystal structural

Matthias Hilder; Marina Lezhnina; Marcus L. Cole; Craig M. Forsyth; Peter C. Junk; Ulrich H. Kynast

2011-01-01

123

High-purity, fine-particle boron nitride powder synthesis at -75 to 750C. Report of investigations\\/1986  

Microsoft Academic Search

Nonoxide ceramics with improved high-temperature properties could substitute for high-temperature alloys and reduce the Nation's dependence on imports of Cr, Co, Ni, and Mn. To meet the objective, the Bureau of Mines conducted research to synthesize ultrafine reactive boron nitride (BN) powders. BN powders were prepared at temperatures ranging from -75 degrees to 750 degrees C. Low-temperature reactions (-75 to

Kalyoncu

1986-01-01

124

Luminescence of powdered uranium glasses  

NASA Technical Reports Server (NTRS)

Measurement of cathodoluminescence and photoluminescence efficiencies in powdered borosilicate glasses having different particle size and different uranium content. Excitation with 100 to 350 keV electrons and with 253.7 nm light was found to produce identical absolute radiant exitance spectra in powdered samples. The most efficient glass was one containing 29.4 wt% B2O3, 58.8 wt% SiO2, 9.8 wt% Na2O and 2.0 wt% UO2.

Eubanks, A. G.; Mcgarrity, J. M.; Silverman, J.

1974-01-01

125

Neutron detectors comprising boron powder  

DOEpatents

High-efficiency neutron detector substrate assemblies comprising a first conductive substrate, wherein a first side of the substrate is in direct contact with a first layer of a powder material comprising .sup.10boron, .sup.10boron carbide or combinations thereof, and wherein a conductive material is in proximity to the first layer of powder material; and processes of making said neutron detector substrate assemblies.

Wang, Zhehui; Morris, Christopher; Bacon, Jeffrey Darnell; Makela, Mark F; Spaulding, Randy Jay

2013-05-21

126

Ceramic oxide powders and the formation thereof  

DOEpatents

Ceramic oxide powders and a method for their preparation. Ceramic oxide powders are obtained using a flame process whereby two or more precursors of ceramic oxides are introduced into a counterflow diffusion flame burner wherein said precursors are converted into ceramic oxide powders. The morphology, particle size, and crystalline form of the ceramic oxide powders are determined by process conditions. 14 figures.

Katz, J.L.; Chenghung Hung.

1993-12-07

127

Ceramic oxide powders and the formation thereof  

DOEpatents

Ceramic oxide powders and a method for their preparation. Ceramic oxide powders are obtained using a flame process whereby two or more precursors of ceramic oxides are introduced into a counterflow diffusion flame burner wherein said precursors are converted into ceramic oxide powders. The morphology, particle size, and crystalline form of the ceramic oxide powders are determined by process conditions.

Katz, Joseph L. (Baltimore, MD); Hung, Cheng-Hung (Baltimore, MD)

1993-01-01

128

Trifluoromethyl-substituted polymers  

NASA Technical Reports Server (NTRS)

Current work sponsored by the grant at Southwest Texas State University is directed toward the synthesis and characterization of: (1) N-alkylated polyamides derived from o-fluorinated diacids; (2) highly fluorinated polyethers; (3) polyesters derived from 2-hydroxy-2-propyl substituted arenes and/or 2,5-difluoroterephthalic acid; and (4) silicon-containing fluoropolymers. Work during the period from 1 July to 31 Dec. 1993 focused primarily on items 3 and 4 and on the development of a phosphorus containing modification of '12F-PEK.'

1993-01-01

129

Polyimides comprising substituted benzidines  

NASA Technical Reports Server (NTRS)

A new class of polyimides and copolyimides made from substituted benzidines and aromatic dianhydrides and other aromatic diamines. The polyimides obtained with said diamines are distinguished by excellent thermal, excellent solubility, excellent electrical properties such as very low dielectric constants, excellent clarity and mechanical properties making the polyimides ideally suited as coating materials for microelectronic apparatii, as membranes for selective molecular or gas separation, as fibers in molecular composites, as high tensile strength, high compression strength fibers, as film castable coatings, or as fabric components.

Harris, Frank W. (Inventor)

1991-01-01

130

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2012 CFR

...heavy wall conductive plastic receptacles not over 454 g (16 ounces) net capacity each, with no more than 25 cans in one outer UN 4G fiberboard box. The inner packagings must be arranged and protected so as to prevent simultaneous ignition of the...

2012-10-01

131

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2013 CFR

...heavy wall conductive plastic receptacles not over 454 g (16 ounces) net capacity each, with no more than 25 cans in one outer UN 4G fiberboard box. The inner packagings must be arranged and protected so as to prevent simultaneous ignition of the...

2013-10-01

132

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2011 CFR

...heavy wall conductive plastic receptacles not over 454 g (16 ounces) net capacity each, with no more than 25 cans in one outer UN 4G fiberboard box. The inner packagings must be arranged and protected so as to prevent simultaneous ignition of the...

2011-10-01

133

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2010 CFR

...heavy wall conductive plastic receptacles not over 454 g (16 ounces) net capacity each, with no more than 25 cans in one outer UN 4G fiberboard box. The inner packagings must be arranged and protected so as to prevent simultaneous ignition of the...

2010-10-01

134

Effect of carbon source on the carbothermal reduction nitridation for synthesis of (Ti, W, Mo, V)(C, N) nanocrystalline powders  

Microsoft Academic Search

The effect of carbon source on the carbothermal reduction–nitridation during synthesizing (Ti, W, Mo, V)(C, N) nanocrystalline powders was investigated. For a systematic comparison, activated carbon, graphite and two kinds of carbon black powder were used as reducing agents in this study. Ultrafine (Ti, W, Mo, V)(C, N) powders with a particle size of ~200–500nm have been produced at 1450°C

Yongzhong Jin; Ying Liu; Jinwen Ye; Binghong Li

2011-01-01

135

Research on Zr 50Al 15? x Ni 10Cu 25Y x amorphous alloys prepared by mechanical alloying with commercial pure element powders  

Microsoft Academic Search

Amorphous Zr50Al15?xNi10Cu25Yx alloy powders were fabricated by mechanical alloying at low vacuum with commercial pure element powders. The effects on glass forming ability of Al partial substituted by Y in Zr50Al15Ni10Cu25 and thermal stability of Si3N4 powders addition were investigated. The as-milled powders were characterized by X-ray diffraction, scanning electron microscopy and differential scanning calorimeter. The results show that partial

Woyun Long; Xueqiong Ouyang; Zhiwei Luo; Jing Li; Anxian Lu

2011-01-01

136

Preparation and characterization of cobalt-substituted anthrax lethal factor  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Cobalt-substituted anthrax lethal factor (CoLF) is highly active. Black-Right-Pointing-Pointer CoLF can be prepared by bio-assimilation and direct exchange. Black-Right-Pointing-Pointer Lethal factor binds cobalt tightly. Black-Right-Pointing-Pointer The electronic spectrum of CoLF reveals penta-coordination. Black-Right-Pointing-Pointer Interaction of CoLF with thioglycolic acid follows a 2-step mechanism. -- Abstract: Anthrax lethal factor (LF) is a zinc-dependent endopeptidase involved in the cleavage of mitogen-activated protein kinase kinases near their N-termini. The current report concerns the preparation of cobalt-substituted LF (CoLF) and its characterization by electronic spectroscopy. Two strategies to produce CoLF were explored, including (i) a bio-assimilation approach involving the cultivation of LF-expressing Bacillus megaterium cells in the presence of CoCl{sub 2}, and (ii) direct exchange by treatment of zinc-LF with CoCl{sub 2}. Independent of the method employed, the protein was found to contain one Co{sup 2+} per LF molecule, and was shown to be twice as active as its native zinc counterpart. The electronic spectrum of CoLF suggests the Co{sup 2+} ion to be five-coordinate, an observation similar to that reported for other Co{sup 2+}-substituted gluzincins, but distinct from that documented for the crystal structure of native LF. Furthermore, spectroscopic studies following the exposure of CoLF to thioglycolic acid (TGA) revealed a sequential mechanism of metal removal from LF, which likely involves the formation of an enzyme: Co{sup 2+}:TGA ternary complex prior to demetallation of the active site. CoLF reported herein constitutes the first spectroscopic probe of LF's active site, which may be utilized in future studies to gain further insight into the enzyme's mechanism and inhibitor interactions.

Saebel, Crystal E.; Carbone, Ryan; Dabous, John R.; Lo, Suet Y. [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada)] [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada); Siemann, Stefan, E-mail: ssiemann@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada)] [Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6 (Canada)

2011-12-09

137

Explicit Substitutions and All That  

NASA Technical Reports Server (NTRS)

Explicit substitution calculi are extensions of the Lambda-calculus where the substitution mechanism is internalized into the theory. This feature makes them suitable for implementation and theoretical study of logic-based tools such as strongly typed programming languages and proof assistant systems. In this paper we explore new developments on two of the most successful styles of explicit substitution calculi: the lambda(sigma)- and lambda(s(e))-calculi.

Ayala-Rincon, Mauricio; Munoz, Cesar; Busnell, Dennis M. (Technical Monitor)

2000-01-01

138

Explicit Substitutions and All That  

NASA Technical Reports Server (NTRS)

Explicit substitution calculi are extensions of the lambda-calculus where the substitution mechanism is internalized into the theory. This feature makes them suitable for implementation and theoretical study of logic-based tools such as strongly typed programming languages and proof assistant systems. In this paper we explore new developments on two of the most successful styles of explicit substitution calculi: the lambda sigma- and lambda S(e)-calculi.

Ayala-Rincon, Mauricio; Munoz, Cesar

2000-01-01

139

Black Smokers  

NSDL National Science Digital Library

Black Smokers explains the phenomena of deep-sea hydrothermal vents that occur under oceans within mid-ocean ridge volcanoes. The site describes deep-sea hydrothermal vent life forms, the ocean floor, and the mid-ocean ridge system. Teacher resources include games and lesson plans about the human impact on black smoker environments, the debate on human versus robotic expeditions, tools and engineering for black smoker expeditions, and how oceanic crust forms and ages. There are reports from expeditions studying black smokers and information on the research vessels and other underwater tools of the expeditions.

140

Brominated carbon black: An EDXD study  

NASA Astrophysics Data System (ADS)

An energy dispersive X-Ray study of pure and brominated carbon black was carried out. The analysis of the diffraction patterns reveals that the low bromine load (ca.1% mol) is trapped into the structure, without significantly modifying it. This allows the application of the difference methods, widely tested for electrolyte solutions, inorganic matrices containing metals and isomorphic substitutions.

Carbone, Marilena; Gontrani, Lorenzo

2014-06-01

141

Thermal evolution behavior of carbides and {gamma} Prime precipitates in FGH96 superalloy powder  

SciTech Connect

The characteristics of rapidly solidified FGH96 superalloy powder and the thermal evolution behavior of carbides and {gamma} Prime precipitates within powder particles were investigated. It was observed that the reduction of powder size and the increase of cooling rate had transformed the solidification morphologies of atomized powder from dendrite in major to cellular structure. The secondary dendritic spacing was measured to be 1.02-2.55 {mu}m and the corresponding cooling rates were estimated to be in the range of 1.4 Multiplication-Sign 10{sup 4}-4.7 Multiplication-Sign 10{sup 5} K{center_dot}s{sup -1}. An increase in the annealing temperature had rendered the phase transformation of carbides evolving from non-equilibrium MC Prime carbides to intermediate transition stage of M{sub 23}C{sub 6} carbides, and finally to thermodynamically stable MC carbides. The superfine {gamma} Prime precipitates were formed at the dendritic boundaries of rapidly solidified superalloy powder. The coalescence, growth, and homogenization of {gamma}' precipitates occurred with increasing annealing temperature. With decreasing cooling rate from 650 Degree-Sign C{center_dot}K{sup -1} to 5 Degree-Sign C{center_dot}K{sup -1}, the morphological development of {gamma} Prime precipitates had been shown to proceed from spheroidal to cuboidal and finally to solid state dendrites. Meanwhile, a shift had been observed from dendritic morphology to recrystallized structure between 900 Degree-Sign C and 1050 Degree-Sign C. Moreover, accelerated evolution of carbides and {gamma}' precipitates had been facilitated by the formation of new grain boundaries which provide fast diffusion path for atomic elements. - Highlights: Black-Right-Pointing-Pointer Microstructural characteristic of FGH96 superalloy powder was investigated. Black-Right-Pointing-Pointer The relation between microstructure, particle size, and cooling rate was studied. Black-Right-Pointing-Pointer Thermal evolution behavior of {gamma} Prime and carbides in loose FGH96 powder was studied.

Zhang Lin, E-mail: zhanglincsu@163.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Liu Hengsan, E-mail: lhsj63@sohu.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); He Xinbo, E-mail: xb_he@163.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Rafi-ud-din, E-mail: rafiuddi@gmail.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Qu Xuanhui, E-mail: quxh@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Qin Mingli, E-mail: mlqin75@hotmail.com [State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, 100083 (China); Li Zhou, E-mail: zhouli621@126.com [National Key Lab of High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing, 100095 (China); Zhang Guoqing, E-mail: g.zhang@126.com [National Key Lab of High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing, 100095 (China)

2012-05-15

142

In situ studies of zeolite syntheses using powder diffraction methods: Crystallization of ``instant zeolite A`` powder and CoAPO-5  

SciTech Connect

A series of hydrothermal zeolite synthesis were performed on a powder diffractometer using synchrotron radiation and a position sensitive detector. Direct observation of the induction period (nucleation stage), crystallization and transformation of zeolite 4A (Na-LTA) was possible due to the intense X-ray beam which allows fast data collection. High pressure experiments were performed, allowing observation of hydrothermal synthesis of a cobalt substituted AlPO{sub 4}-zeolite, CoAPO-5, up to 165{degrees}C. The temperature dependence of crystallization rates of CoAPO-5 was studied. This is to our knowledge the first time resolved powder diffraction studies of zeolite syntheses using angle dispersive synchrotron powder diffraction.

Norby, P. [Odense Univ. (Denmark). Dept. of Chemistry; Christensen, A.N. [Aarhus Univ. (Denmark). Dept. of Chemistry; Hanson, J.C. [Brookhaven National Lab., Upton, NY (United States)

1994-02-01

143

Rapid hydrothermal flow synthesis and characterisation of carbonate- and silicate-substituted calcium phosphates.  

PubMed

A range of crystalline and nano-sized carbonate- and silicate-substituted hydroxyapatite has been successfully produced by using continuous hydrothermal flow synthesis technology. Ion-substituted calcium phosphates are better candidates for bone replacement applications (due to improved bioactivity) as compared to phase-pure hydroxyapatite. Urea was used as a carbonate source for synthesising phase pure carbonated hydroxyapatite (CO?-HA) with ?5?wt% substituted carbonate content (sample 7.5CO?-HA) and it was found that a further increase in urea concentration in solution resulted in biphasic mixtures of carbonate-substituted hydroxyapatite and calcium carbonate. Transmission electron microscopy images revealed that the particle size of hydroxyapatite decreased with increasing urea concentration. Energy-dispersive X-ray spectroscopy result revealed a calcium deficient apatite with Ca:P molar ratio of 1.45 (±0.04) in sample 7.5CO?-HA. For silicate-substituted hydroxyapatite (SiO?-HA) silicon acetate was used as a silicate ion source. It was observed that a substitution threshold of ?1.1?wt% exists for synthesis of SiO?-HA in the continuous hydrothermal flow synthesis system, which could be due to the decreasing yields with progressive increase in silicon acetate concentration. All the as-precipitated powders (without any additional heat treatments) were analysed using techniques including Transmission electron microscopy, X-ray powder diffraction, Differential scanning calorimetry, Thermogravimetric analysis, Raman spectroscopy and Fourier transform infrared spectroscopy. PMID:22983020

Chaudhry, Aqif A; Knowles, Jonathan C; Rehman, Ihtesham; Darr, Jawwad A

2013-09-01

144

The Atomic Distribution in Red and Black Phosphorus and the Crystal Structure of Black Phosphorus  

Microsoft Academic Search

No satisfactory crystal structure determination has been made of any of the forms of phosphorus. Five samples of black phosphorus gave identical powder patterns different from those reported by Linck and Jung, whose rhombohedral structure gives improbable interatomic distances and coordination. A sample which had been prepared at room temperature and 35,000 atmospheres gave the diffuse rings of an ``amorphous''

Ralph Hultgren; N. S. Gingrich; B. E. Warren

1935-01-01

145

The crystal chemistry and thermal stability of sol-gel prepared fluoride-substituted talc  

NASA Astrophysics Data System (ADS)

Stable, colloidal sols were prepared from the addition of methanolic (Mg(OCH3)2) to one equivalent of H2O2 in methanol. Fluoride was quantitatively incorporated by treatment of these sols with HF. Stable sols were obtained when sols, prepared from the acid catalyzed hydrolysis of tetramethylorthosilicate (TMOS), were combined with these fluoridated magnesium sols. Solvent removal gave xerogels, which were calcined, and treated with stoichiometric quantities of water at 750 °C and 1.6 kbar. The resulting products were high-purity, single-phase talcs with fluoride substitution as high as 75 mole percent; the fluoride substitution is higher than any previously reported. Powder XRD analysis showed a non-linear decrease in d(060) spacing with increasing fluoride substitution, which is attributed to a decrease in the b-dimension of talc when fluoride replaced hydroxide. FTIR spectroscopy showed a non-linear decrease in vO-H in talc with increasing fluoride substitution, which was attributed to an increase in hydrogen bonding of the OH groups and an increase in the electronegativity of the octahedral layer in talc with increasing fluoride substitution. The thermal stability of the talcs was studied using DT and TG, powder XRD, FTIR, and fluoride ion-selective electrode analyses. Synthetic talc without fluoride decomposed at 860 °C, whereas talc with 68% fluoride substitution showed essentially no decomposition when heated to 1060 °C. When heated to 1200 °C, 68% fluoride substituted talc formed amorphous material, enstatite, protoenstatite, norbergite, and chondrodite. The upper stability temperature of talc, taken as the maximum rate of the first endothermic event in its DTA profile, was dependent on the extent of fluoride substitution. Talc with 100% fluoride substitution is predicted to be stable up to ˜1100°C.

Rywak, A. A.; Burlitch, J. M.

1996-10-01

146

Peierls substitution for magnetic Bloch bands  

E-print Network

We consider the one-particle Schro\\"odinger operator in two dimensions with a periodic potential and a strong constant magnetic field perturbed by slowly varying non-periodic scalar and vector potentials, $\\phi(\\epsilon x)$ and $A(\\epsilon x)$, for $\\epsilon\\ll 1$. For each isolated family of magnetic Bloch bands we derive an effective Hamiltonian that is unitarily equivalent to the restriction of the Schro\\"odinger operator to a corresponding almost invariant subspace. At leading order, our effective Hamiltonian can be interpreted as the Peierls substitution Hamiltonian widely used in physics for non-magnetic Bloch bands. However, while for non-magnetic Bloch bands the corresponding result is well understood, both on a heuristic and on a rigorous level, for magnetic Bloch bands it is not clear how to even define a Peierls substitution Hamiltonian beyond a formal expression. The source of the difficulty is a topological obstruction: In contrast to the non-magnetic case, magnetic Bloch bundles are generically not trivializable. Thus, Peierls substitution Hamiltonians for magnetic Bloch bands turn out to be pseudo-differential operators acting on sections of non-trivial vector bundles over a two-torus, the reduced Brillouin zone. Part of our contribution is the construction of a suitable Weyl calculus for such operators. As an application we construct a family of canonical one-band Hamiltonians $H_\\theta$ for magnetic Bloch bands with Chern number $\\theta\\in\\mathbb{Z}$ that generalizes the Hofstadter model $H_{\\theta=0}$ for a single non-magnetic Bloch band. It turns out that the spectrum of $H_\\theta$ is independent of $\\theta$ and thus agrees with the Hofstadter spectrum depicted in his famous (black and white) butterfly. However, the resulting Chern numbers of subbands, corresponding to Hall conductivities, depend on $\\theta$, and thus the models lead to different colored butterflies.

Silvia Freund; Stefan Teufel

2013-12-20

147

Are black holes totally black?  

E-print Network

Geodesic completeness needs existence near the horizon of the black hole of "white hole" geodesics coming from the region inside of the horizon. Here we give the classification of all such geodesics with the energies $E/m \\le 1$ for the Schwarzschild and Kerr's black hole. The collisions of particles moving along the "white hole" geodesics with those moving along "black hole" geodesics are considered. Formulas for the increase of the energy of collision in the centre of mass frame are obtained and the possibility of observation of high energy particles arriving from the black hole to the Earth is discussed.

A. A. Grib; Yu. V. Pavlov

2014-10-21

148

Storage study and quality evaluation of coconut protein powder.  

PubMed

Coconut skim milk and insoluble protein are 2 major byproducts in the production of virgin coconut oil. Coconut skim milk was homogenized along with insoluble protein and spray dried to obtain a value-added product, namely, coconut protein powder (CPP). This study deals with the storage study of CPP under different conditions (refrigerated [control], ambient and accelerated). CPP samples were withdrawn periodically at designated intervals of 15 d for accelerated and control, and 30 d for ambient condition. CPP stored at different conditions exhibited marginal moisture uptake (by 0.74 % w/w for control, 0.76 % w/w for ambient, and 1.26 % w/w for accelerated condition) and as a result, had very little effect on the functional properties of the powder. Withdrawn CPP was tested for sensory quality aspects and subjected to instrumental analysis as well. Withdrawn CPP was incorporated as a milk substitute in dessert (Kheer). Quantitative descriptive analysis of the powder and product (Kheer) showed no significant difference in attributes of CPP during the storage period of 2 mo. Electronic nose analysis revealed that CPP samples were not much different with respect to aroma pattern matching, respectively. PMID:24245897

Naik, Aduja; Prakash, Maya; R, Ravi; Raghavarao, Ksms

2013-11-01

149

Triboelectric charging of polymer powders in fluidization and transport processes  

Microsoft Academic Search

Steady flow of powder at a desired rate is a necessity for controlling thickness and uniformity of the deposited powder layer in electrostatic spray painting. In most powder coating applications, the polymer powder is fluidized to transport the powder to the spray gun using a powder pump. The powder delivery tube is often long; sometimes in excess of 10 m.

J. R. Mountaint; D. L. Wankum; M. K. Mazumder; T. Chasser; P. Pettit

1997-01-01

150

Displacement, Substitution, Sublimation: A Bibliography.  

ERIC Educational Resources Information Center

Sigmund Freund worked with the mechanisms of displacement, substitution, and sublimation. These mechanisms have many similarities and have been studied diagnostically and therapeutically. Displacement and substitution seem to fit in well with phobias, hysterias, somatiyations, prejudices, and scapegoating. Phobias, prejudices, and scapegoating…

Pedrini, D. T.; Pedrini, Bonnie C.

151

MICROWAVE PHOTOCHEMISTRY OF SUBSTITUTED PHENOLS  

E-print Network

MICROWAVE PHOTOCHEMISTRY OF SUBSTITUTED PHENOLS V. C�rkva, J. Kurf�rstov�, M. H�jek Institute into the microwave field (MW) has been known for long time [1-3]. The low powered and low-pressure electrodeless of microwave photochemistry of substituted phenols in an original photoche- mical reactor consisting of EDL

Cirkva, Vladimir

152

Substituting fossil fuels with biomass  

Microsoft Academic Search

Replacing fossil fuels with sustainably-produced biomass reduces net CO2 emissions. We express the efficiency of this substitution in reduced emissions per unit of used land or biomass. The substitution costs are calculated as the cost difference between a continued use of fossil fuels at current prices and a use of biomass. The biomass technologies are assumed to be implemented when

Leif Gustavsson; Per Svenningsson

1996-01-01

153

A Substitution Operation for Constraints  

Microsoft Academic Search

In order to reduce the search space in finite constraint satisfaction problems, a number of different preprocessing schemes have been proposed. This paper introduces a substitution operation for constraints. This new operation generalizes both the idea of enforcing consistency and the notion of label substitution introduced by Freuder. We show that the constraints in a problem may be replaced by

Peter Jeavons; David A. Cohen; Martin C. Cooper

1994-01-01

154

Synthesis, sintering and characterization of Al2O 3TiC nano-composites powders from carbon coated precursors  

Microsoft Academic Search

Synthesis, sintering and characterization of Al2O3-TiC nano-composite powders from carbon coated precursors were investigated. Degussa P-25 titanium dioxide, Cabot carbon black, and Alfa Aesar aluminum were the initial starting powders. Hydrocarbon gas (C3H6) was used as the carbon source for the carbon coated precursors. Analytical methods employed in this research were BET surface area measurement, X-ray diffraction (XRD), transmission electron

Hisashi Kaga

2003-01-01

155

Pharmaceutically Engineering Powders Using FHMG  

Microsoft Academic Search

Fluidized hot melt granulation (FHMG) is an innovative granulation process that has distinct advantages over techniques that are typically used in the pharmaceutical industry for powder agglomeration and mixing. The aim of this research was to investigate process and formulation parameters that affect FHMG, in a pharmaceutical context, using Lutrol® F68 (copolymer of polyoxyethylene-polyoxypropylene) as a meltable binder with inert

G. Walker; S. Bell; M. Vann; H. Zhai; D. Jones; G. Andrews

2007-01-01

156

Metallography of powder metallurgy materials  

SciTech Connect

The primary distinction between the microstructure of an ingot metallurgy/wrought material and one fabricated by the powder metallurgy route of pressing followed by sintering is the presence of porosity in the latter. In its various morphologies, porosity affects the mechanical, physical, chemical, electrical and thermal properties of the material. Thus, it is important to be able to characterize quantitatively the microstructure of powder metallurgy parts and components. Metallographic procedures necessary for the reliable characterization of microstructures in powder metallurgy materials are reviewed, with emphasis on the intrinsic challenges presented by the presence of porosity. To illustrate the utility of these techniques, five case studies are presented involving powder metallurgy materials. These case studies demonstrate problem solving via metallography in diverse situations: failure of a tungsten carbide-coated precipitation hardening stainless steel, failure of a steel pump gear, quantification of the degree of sinter (DOS), simulation of performance of a porous filter using automated image analysis, and analysis of failure in a sinter brazed part assembly.

Lawley, Alan; Murphy, Thomas F

2003-12-15

157

SHOCK COMPRESSION PROCESSING OF POWDERS  

Microsoft Academic Search

Shock compression processing is emerging as a novel technique for fabrication of esoteric materials. Not only can metal and ceramic powders be dynamically consolidated, but both equilibrium and non-equilibrium structures can be synthesized under the high pressure regime during the passage of shock waves of sufficient magnitude and duration. The shock waves can be generated by impact from a plate

N. N. Thadhani

1988-01-01

158

40 CFR 721.3063 - Substituted phenyl azo substituted phenyl esters (generic name).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Substituted phenyl azo substituted phenyl esters (generic name). 721.3063 Section...Chemical Substances § 721.3063 Substituted phenyl azo substituted phenyl esters (generic...

2010-07-01

159

Polymer quenched prealloyed metal powder  

DOEpatents

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3 % Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

Hajaligol, Mohammad R. (Midlothian, VA); Fleischhauer, Grier (Midlothian, VA); German, Randall M. (State College, PA)

2001-01-01

160

Intradermal needle-free powdered drug injection  

E-print Network

This thesis presents a new method for needle-free powdered drug injection. The design, construction, and testing of a bench-top helium-powered device capable of delivering powder to controllable depths within the dermis ...

Liu, John (John Hsiao-Yung)

2012-01-01

161

THE NITRATION OF POWDERED URANIUM BY NITROGEN  

Microsoft Academic Search

The nitration of powdered uranium by nitrogen was studied by- ; thermograviimetry- between 300 and 700 deg C. The results obtained show the ; complexity of a powdered soidgas reaction and chiefly the effect of granulometry. ; (trauth);

C. Moreau; J. Philippot

1961-01-01

162

40 CFR 721.10626 - 1,4-Butanediol, polymer with substituted alkane and substituted methylene biscarbomonocycle, 2...  

Code of Federal Regulations, 2013 CFR

...4-Butanediol, polymer with substituted alkane and substituted methylene biscarbomonocycle...4-Butanediol, polymer with substituted alkane and substituted methylene biscarbomonocycle...4-butanediol, polymer with substituted alkane and substituted methylene...

2013-07-01

163

40 CFR 721.9820 - Substituted triazole.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Substituted triazole. 721.9820 Section 721.9820...Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant...generically identified as a substituted triazole (PMN P-90-1731) is subject...

2012-07-01

164

40 CFR 721.9820 - Substituted triazole.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Substituted triazole. 721.9820 Section 721.9820...Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant...generically identified as a substituted triazole (PMN P-90-1731) is subject...

2013-07-01

165

40 CFR 721.4280 - Substituted hydrazine.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Substituted hydrazine. 721.4280 Section 721.4280...Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant...identified generically as substituted hydrazine (PMN P-90-594) is subject...

2011-07-01

166

40 CFR 721.4280 - Substituted hydrazine.  

... 2014-07-01 false Substituted hydrazine. 721.4280 Section 721.4280...Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant...identified generically as substituted hydrazine (PMN P-90-594) is subject...

2014-07-01

167

40 CFR 721.4280 - Substituted hydrazine.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Substituted hydrazine. 721.4280 Section 721.4280...Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant...identified generically as substituted hydrazine (PMN P-90-594) is subject...

2012-07-01

168

40 CFR 721.4280 - Substituted hydrazine.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Substituted hydrazine. 721.4280 Section 721.4280...Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant...identified generically as substituted hydrazine (PMN P-90-594) is subject...

2013-07-01

169

40 CFR 721.4280 - Substituted hydrazine.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Substituted hydrazine. 721.4280 Section 721.4280...Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant...identified generically as substituted hydrazine (PMN P-90-594) is subject...

2010-07-01

170

40 CFR 721.3360 - Substituted ethanolamine.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted ethanolamine. 721.3360 Section 721.3360...Substances § 721.3360 Substituted ethanolamine. (a) Chemical substance and significant...identified generically as substituted ethanolamine (PMN P-91-490) is subject...

2010-07-01

171

40 CFR 721.9820 - Substituted triazole.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Substituted triazole. 721.9820 Section 721.9820...Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant...generically identified as a substituted triazole (PMN P-90-1731) is subject...

2011-07-01

172

40 CFR 721.9820 - Substituted triazole.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Substituted triazole. 721.9820 Section 721.9820...Substances § 721.9820 Substituted triazole. (a) Chemical substance and significant...generically identified as a substituted triazole (PMN P-90-1731) is subject...

2010-07-01

173

14 CFR 1260.55 - Reports substitution.  

Code of Federal Regulations, 2011 CFR

... GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.55 Reports substitution. Reports Substitution October 2000 Technical Reports may be substituted for the required Performance Reports. The title page of...

2011-01-01

174

14 CFR 1260.55 - Reports substitution.  

... GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.55 Reports substitution. Reports Substitution October 2000 Technical Reports may be substituted for the required Performance Reports. The title page of...

2014-01-01

175

14 CFR 1260.55 - Reports substitution.  

Code of Federal Regulations, 2013 CFR

... GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.55 Reports substitution. Reports Substitution October 2000 Technical Reports may be substituted for the required Performance Reports. The title page of...

2013-01-01

176

14 CFR 1260.55 - Reports substitution.  

Code of Federal Regulations, 2010 CFR

... GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.55 Reports substitution. Reports Substitution October 2000 Technical Reports may be substituted for the required Performance Reports. The title page of...

2010-01-01

177

14 CFR 1260.55 - Reports substitution.  

Code of Federal Regulations, 2012 CFR

... GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.55 Reports substitution. Reports Substitution October 2000 Technical Reports may be substituted for the required Performance Reports. The title page of...

2012-01-01

178

LAND USE AND OWNERSHIP, POWDER RIVER BASIN  

E-print Network

Chapter PM LAND USE AND OWNERSHIP, POWDER RIVER BASIN By T.T. Taber and S.A. Kinney In U........................................PM-1 Map Information for the Powder River Basin Land Use and Land Cover map...........................................................PM-2 Map Information for the Powder River Basin Subsurface Ownership map

179

Resin Powder Slurry Process for Composite Fabrication  

NASA Technical Reports Server (NTRS)

Potentially useful process for fabrication of fiber-reinforced resinmatrix composites is powder slurry technique. Applicability of technique demonstrated using powdered resin made from thermoplastic polyimide LaRC/ TPI (thermoplastic polyimide). Use of process circumvents need for such high-cost organic solvents as N-methylpyrrolidinone and diglyme (diglycol methyl ether). Two basic slurries for LaRC/TPI powder investigated.

Mike, R. A.

1986-01-01

180

Homogeneous precipitation of nickel hydroxide powders  

NASA Astrophysics Data System (ADS)

Structure of nickel precipitate from decomposition of urea was found to be alpha-Ni(OH)2. FTIR analysis revealed the intercalation of cyanate (OCN), which is an intermediate product of urea decomposition. This observation implied that the assumption of single step decomposition of urea to carbon dioxide and ammonia was over simplified. Role of critical experimental parameters like initial pH and metal ion concentration on the powder characteristics was carried out. Numerical solutions to reaction pathways predicted significant accumulation of the intermediate cyanate in the time-temperature range investigated. Numerical simulations included the effects of hydrolysis products of Ni2+ and Ni-amine, Ni-cyanate, and Ni-carbonate complexes. Chemical analysis of the precipitate showed a decrease in nitrogen content with increasing reaction times. This was consistent with the predicted decrease in concentration of Ni-cyanate complexes with time. Layer double hydroxides (LDHs) are intercalation compounds represented by the formula [M2+1-xM3+ x(OH)2]x+[An-x/n ]x-·mH2O. alpha-Ni(OH) 2 and Ni-Al layer double hydroxides precipitated by urea were investigated with FTIR and XPS. The role of cyanate in nucleation and growth of precipitates is demonstrated. In the early stages, cyanate ion is found mainly to be grafted into alpha-Ni(OH)2 via nitrogen, whereas later in the growth stages, it is bonded through oxygen. In LDHs cyanate remains N-bonded. Precipitation with substituted ureas, revealed the link between spectral features and structures observed in XRD patterns. With slower decomposition rates and low levels of supersaturation an extensively hydrated structure was observed. From the two phases of Ni(OH)2, alpha-phase, with its larger interlayer spacing, offers enhanced electrochemical properties but it transforms into thermodynamically stable beta-phase. Stabilizing effects of Ni2+ substitution with Co2+ and Al3+ was investigated. A number of three-component LDHs (TCLDHs) with Ni2+1-(x+y) /Co2+x and Al3+y (x and y were varied between 0.00 and, 0.25) were produced by urea precipitation. From the compositions studied, the ones containing [Al3+] o ? 0.015 M resulted with the LDH structure and proved to be stable in the electrolyte for prolonged times. Chronopotentiometry results indicated that TC-LDHs could deliver capacities up to about 30% higher than the beta-phase.

Mavis, Bora

181

[Impact of directly compressed auxiliary materials on powder property of fermented cordyceps powder].  

PubMed

To investigate such physical indexes as hygroscopicity, angle of repose, bulk density, fillibility of compression of mixed powder of directly compressed auxiliary materials and fermented cordyceps powder by using micromeritic study methods. The results showed that spray-dried lactose Flowlac100 and microcrystalline cellulose Avicel PH102 had better effect in liquidity and compressibility on fermented cordyceps powder than pregelatinized starch. The study on the impact of directly compressed auxiliary materials on the powder property of fermented cordyceps powder had guiding significant to the research of fermented cordyceps powder tablets, and could provide basis for the development of fermented cordyceps powder tablets. PMID:24754170

Chen, Li-Hua; Yue, Guo-Chao; Guan, Yong-Mei; Yang, Ming; Zhu, Wei-Feng

2014-01-01

182

Black tea  

MedlinePLUS

... combining caffeine, an ingredient in black tea, with ephedra and creatine might increase the risk of serious ... 600 mg of caffeine, 40-60 mg of ephedra, and a variety of other supplements daily for ...

183

Composition of reactive powder concretes  

Microsoft Academic Search

Development of an ultra-high strength ductile concrete designated RPC (Reactive Powder Concrete), was made possible by the application of a certain number of basic principles relating to the composition, mixing and post-set heat curing of the concrete.RPC 200, which can be used under job site conditions similar to those for conventional high performance concretes, can be used in the construction

Pierre Richard; Marcel Cheyrezy

1995-01-01

184

DESIGNING ENVIRONMENTALLY BENIGN SOLVENT SUBSTITUTES  

EPA Science Inventory

Since the signing of 1987 Montreal Protocol, reducing and eliminating the use of harmful solvents has become an internationally imminent environmental protection mission. Solvent substitution is an effective way to achieve this goal. The Program for Assisting the Replacement of...

185

Nucleophilic Substitution by Benzodithioate Anions.  

ERIC Educational Resources Information Center

Describes a two-session experiment designed to provide a good illustration of, and to improve student knowledge of, the Grignard reaction and nucleophilic substitution. Discusses the procedure, experimental considerations, and conclusion of this experiment. (CW)

Bonnans-Plaisance, Chantal; Gressier, Jean-Claude

1988-01-01

186

The Effect of Filler Loading on Curing and Mechanical Properties of Natural Rubber\\/recycled Rubber Powder Blends  

Microsoft Academic Search

Curing characteristics and mechanical properties of carbon black– and silica-filled natural rubber (NR)\\/recycled rubber powder (RRP) blends were studied. Results indicate that the minimum torque and maximum torque increase with increasing filler loading in the compounds, whereas scorch time shows a decreasing trend. Cure time of carbon black–filled NR\\/RRP blends decreases with increasing filler loading whereas silca-filled NR\\/RRP blends show

H. Ismail; R. Nordin; A. M. Noor

2005-01-01

187

Powder Coatings Technology Update. Final report  

SciTech Connect

The objective of this report is to provide an overview of the current status of powder-coating technology. Because powder coatings are applied as dry, finely divided particles, there are no volatile organic compounds (VOC's) released during application, and only minute quantities are released during the curing process. Therefore, the increased use of powder coatings, as an alternative to liquid solvent-based coatings, represents a significant reduction in emissions of VOC's. The report describes current powder-coating materials and equipment, end uses, and economic advantages of the use of powder coatings. Included in the report are discussions of the disadvantages and potential problems identified early in the powder-coating-development process. The report addresses the resolutions of many of these problems. The report is intended to be of use to State and local agencies in their evaluation of powder coatings as an alternative to coatings containing VOC's.

Hester, C.I.; Nicholson, R.L.; Cassidy, M.A.

1989-09-01

188

Homozygous tyrosinase gene mutation in an American black with tyrosinase-negative (type IA) oculocutaneous albinism.  

PubMed Central

We have identified a tyrosinase gene mutation in an American black with classic, tyrosinase-negative oculocutaneous albinism. This mutation results in an amino acid substitution (Cys----Arg) at codon 89 of the tyrosinase polypeptide. The proband is homozygous for the substitution, suggesting that this mutation may be frequently associated with tyrosinase-negative oculocutaneous albinism in blacks. Images Figure 1 Figure 2 Figure 3 PMID:1899321

Spritz, R A; Strunk, K M; Hsieh, C L; Sekhon, G S; Francke, U

1991-01-01

189

Powder metallurgy: Solid and liquid phase sintering of copper  

NASA Technical Reports Server (NTRS)

Basic powder metallurgy (P/M) principles and techniques are presented in this laboratory experiment. A copper based system is used since it is relatively easy to work with and is commercially important. In addition to standard solid state sintering, small quantities of low melting metals such as tin, zinc, lead, and aluminum can be added to demonstrate liquid phase sintering and alloy formation. The Taguchi Method of experimental design was used to study the effect of particle size, pressing force, sintering temperature, and sintering time. These parameters can be easily changed to incorporate liquid phase sintering effects and some guidelines for such substitutions are presented. The experiment is typically carried out over a period of three weeks.

Sheldon, Rex; Weiser, Martin W.

1993-01-01

190

New technology for separating resin powder and fiberglass powder from fiberglass-resin powder of waste printed circuit boards.  

PubMed

New recycling technologies have been developed lately to enhance the value of the fiberglass powder-resin powder fraction (FRP) from waste printed circuit boards. The definite aim of the present paper is to present some novel methods that use the image forces for the separation of the resin powder and fiberglass powder generated from FRP during the corona electrostatic separating process. The particle shape charactization and particle trajectory simulation were performed on samples of mixed non-metallic particles. The simulation results pointed out that particles of resin powder and particles of fiberglass powder had different detach trajectories at the conditions of the same size and certain device parameters. An experiment carried out using a corona electrostatic separator validated the possibility of sorting these particles based on the differences in their shape characteristics. The differences in the physical properties of the different types of particles provided the technical basis for the development of electrostatic separation technologies for the recycling industry. PMID:24678800

Li, Jia; Gao, Bei; Xu, Zhenming

2014-05-01

191

Combustion synthesis and characterization of substituted lithium cobalt oxides in lithium batteries  

Microsoft Academic Search

Substituted lithium cobaltates LiCo0.5M0.5O2 (where M=Ni, Mg, Mn, Zn) have been synthesized by the combustion of mixtures obtained from aqueous solutions containing the respective metal nitrates, LiNO3, and urea in stoichiometric amounts. The mixtures, when dried and fired at 700°C, ignite and yield submicron-sized powders. Physical properties of the synthesized products are discussed in the light of structural (XRD, SEM)

C Julien; M. A Camacho-Lopez; T Mohan; S Chitra; P Kalyani; S Gopukumar

2000-01-01

192

Influence of citrate-nitrate reaction mixture packing on ceramic powder properties  

NASA Astrophysics Data System (ADS)

Lanthanum chromite-based materials have a good prospect for use in various high temperature applications, as well as an SOFC separator. A citrate-nitrate gel combustion reaction was used for the preparation of submicron crystalline strontium-substituted lanthanum chromite (LSC). The effect of the fuel-oxidant molar ratio and sample form prior to combustion was investigated in terms of reaction period, phase formation, particle size, morphology and agglomerate formation. Several characterization methods including scanning electron microscopy, mercury porosimetry, BET measurement, X-ray powder diffraction and thermal analysis were used to evaluate the influence of reaction mixture packing on powder characteristics for different citrate-nitrate (c/n) ratios. It was shown that the reaction period depends on the fuel/oxidant ratio and reaction mixture packing. The LSC powders prepared via the combustion route exhibited surface areas of about 12 m 2/g for the loose packed layer prepared samples and 7 to 11 m 2/g for samples prepared from a pellet. The nature of the agglomerates was studied from the pore size distribution in the green compacts pressed at different pressures. The sintering behaviour of powders and some of the electrical properties of sintered samples are reported. Sintering tests on LSC powders prepared via the combustion route showed that the sintering process started at about 900°C and proceeded in two steps in the presence of a liquid phase.

Zupan, Klementina; Kolar, Drago; Marinšek, Marjan

193

Thixoforming of Stellite Powder Compacts  

NASA Astrophysics Data System (ADS)

Thixoforming involves processing metallic alloys in the semi-solid state. The process requires the microstructure to be spheroidal when part-solid and part-liquid i.e. to consist of solid spheroids surrounded by liquid. The aim of this work was to investigate whether powder compacts can be used as feedstock for thixoforming and whether the consolidating pressure in the thixoformer can be used to remove porosity from the compact. The powder compacts were made from stellite 6 and stellite 21 alloys, cobalt-based alloys widely used for e.g. manufacturing prostheses. Isothermal heat treatments of small samples in the consolidated state showed the optimum thixoforming temperature to be in the range 1340°C-1350°C for both materials. The alloys were thixoformed into graphite dies and flowed easily to fill the die. Porosity in the thixoformed components was lower than in the starting material. Hardness values at various positions along the radius of the thixoformed demonstrator component were above the specification for both alloys.

Hogg, S. C.; Atkinson, H. V.; Kapranos, P.

2007-04-01

194

Selective laser sintering of amorphous metal powder  

Microsoft Academic Search

For the first time, selective sintering of amorphous PtCuNiP powder with a pulsed Nd:YAG laser has been studied. Upon pulsed interaction, the grains melt only superficially to build necks between the grains. Depending on the laser parameters, the sintered material can be crystallized or retained amorphous. By contrast with crystalline powder, laser sintering of amorphous powder is achieved at substantially

P. Fischer; A. Blatter; V. Romano; H. P. Weber

2005-01-01

195

Characterization of tribocharging properties of powder paint  

Microsoft Academic Search

The charge-to-mass ratio (q\\/m) of individual particles plays a vital role in the powder coating process. Simultaneous measurements of particle size and electrostatic charge were performed on triboelectrically charged powder paint and other powders in the particle size range 1.0 to 65.0 ?m in diameter. An electrical single particle aerodynamic relaxation time (ESPART) analyzer was used to measure electrostatic charge

M. K. Mazumder; S. Banerjee; R. E. Ware; C. Mu; N. Kaya; C. C. Huang

1994-01-01

196

Characterization of tribocharging properties of powder paint  

Microsoft Academic Search

Simultaneous measurements of particle size and electrostatic charge was performed on charged powder paint and other powders in the particle size range from 1.0 to 65.0 ?m in diameter. An electrical single-particle aerodynamic relaxation time analyzer was used to measure electrostatic charge and aerodynamic size distributions on a single particle basis and in a noninvasive manner. The powders were triboelectrically

M. K. Mazumder; S. Banerjee; R. E. Ware; N. Kaya; C. C. Huang

1992-01-01

197

Surface Functional Characteristics (C, O, S) of Waste Tire-Derived Carbon Black before and after Steam Activation  

Microsoft Academic Search

The effects of steam activation on the surface functional characteristics of waste tire-derived carbon black were investigated. Two carbon-based materials, powdered carbon black (PCB) and PCB-derived powdered activated carbon (PCB-PAC), were selected for this study. A stainless steel tubular oven was used to activate the PCB at an activation temperature of 900 °C and 1 atm using steam as an

Hsun-Yu Lin; Wei-Chin Chen; Chung-Shin Yuan; Chung-Hsuang Hung; John Koupal; Fred Minassian; Hannah Murray; Mani Natarajan; Maurice Chemweno; Leemer Cernohlavek; William Jacoby; Antonio Cardoso; Audrey Levine; Lisa Rhea; Karsten Baumann; R. K. M. Jayanty; James Flanagan; Menouer Boughedaoui; Rabah Kerbachi; Robert Joumard; Isaac Amponsah; Kenneth Harrison; Dimitris Rizos; Paul Ziehl; Cory Carter; Norman Eatough; Delbert Eatough; Neal Olson; Russell Long; Brett Grover; Michael Kleinman; Robert Cary; Philip Hopke; William Wilson; Yasuhiro Fukushima; Pao-Wen Liu; Jiun-Horng Tsai; Cheng Lee; Ting Tseng; Mahmood Alimahmoodi; Catherine Mulligan; Hung-Yueh Lin; Jehng-Jung Kao; Tim Keener

2008-01-01

198

Low cost photovoltaic modules based on dye sensitized nanocrystalline titanium dioxide and carbon powder  

Microsoft Academic Search

A new type of photovoltaic module based on monolithically series connected dye sensitized photoelectrochemical cells is described. Each solar cell element consists of three porous layers on a transparent conducting substrate, namely a photoelectrode of dye sensitized nanocrystalline TiO2 (anatase), a spacer of electrically insulating, light reflecting particles of TiO2 (rutile), and a counterelectrode of graphite powder and carbon black.

Andreas Kay; Michael Grätzel

1996-01-01

199

Biological background of dermal substitutes.  

PubMed

Dermal substitutes are of major importance in treating full thickness skin defects, both in acute and chronic wounds. In this review we will outline specific requirements of three classes of dermal substitutes: Biological and clinical requirements will be translated to composition, physical structure, immunological properties and cell-matrix interactions of the various materials. Important properties like pore size, cell adhesion sites (e.g. RGD sequences), crosslinking, degradability and the presence of a basement membrane will be discussed for each of the different classes of materials. PMID:19897310

van der Veen, Vincent C; van der Wal, Martijn B A; van Leeuwen, Michiel C E; Ulrich, Magda M W; Middelkoop, Esther

2010-05-01

200

Black Flies  

NSDL National Science Digital Library

Information about the common annoyance pest the Black Fly. The flies life cycle and control strategy are covered. While the information is specific to Los Angeles California, the same strategies are effective elsewhere. Personal protection information is also offered and is universally effective.

0002-11-30

201

Black Carbon  

NSDL National Science Digital Library

Black carbon, composed of tiny particles of soot, is produced whenever organic substances like fossil fuels, firewood or coal is incompletely burned. These particles are polluting the air and causing serious health and environmental concerns for people around the world. "Changing Planet" is produced in partnership with the National Science Foundation.

Learn, Nbc

2010-10-07

202

Preparation techniques for ceramic waste form powder  

SciTech Connect

The electrometallurgical treatment of spent nuclear fuels result in a chloride waste salt requiring geologic disposal. Argonne National Laboratory (ANL) is developing ceramic waste forms which can incorporate this waste. Currently, zeolite- or sodalite-glass composites are produced by hot isostatic pressing (HIP) techniques. Powder preparations include dehydration of the raw zeolite powders, hot blending of these zeolite powders and secondary additives. Various approaches are being pursued to achieve adequate mixing, and the resulting powders have been HIPed and characterized for leach resistance, phase equilibria, and physical integrity.

Hash, M.C.; Pereira, C.; Lewis, M.A. [and others

1997-08-01

203

40 CFR 721.5340 - Substituted benzothiazole-azo-substituted benzoquinoline nickel complex (generic).  

Code of Federal Regulations, 2010 CFR

...benzothiazole-azo-substituted benzoquinoline nickel complex (generic). 721.5340 Section...benzothiazole-azo-substituted benzoquinoline nickel complex (generic). (a) Chemical...benzothiazole-azo-substituted benzoquinoline nickel complex (PMN P-99-897) is...

2010-07-01

204

40 CFR 721.1555 - Substituted phenyl azo substituted benzenediazonium salt.  

Code of Federal Regulations, 2012 CFR

...substituted benzenediazonium salt. 721.1555 Section 721...substituted benzenediazonium salt. (a) Chemical substance...substituted benzenediazonium salt (PMN P-92-652) is subject...5). (ii) Release to water. Requirements as...

2012-07-01

205

40 CFR 721.1555 - Substituted phenyl azo substituted benzenediazonium salt.  

Code of Federal Regulations, 2011 CFR

...substituted benzenediazonium salt. 721.1555 Section 721...substituted benzenediazonium salt. (a) Chemical substance...substituted benzenediazonium salt (PMN P-92-652) is subject...5). (ii) Release to water. Requirements as...

2011-07-01

206

Red oak and black walnut growth increased with minesoil ripping  

Microsoft Academic Search

Red oak, black walnut, and black walnut with autumn olive, a “nitrogen-fixing” shrub, were planted on graded, compacted cast overburden (topsoil-substitute) minesoil with a dense ground cover consisting chiefly of tall fescue grass. Compaction was mitigated by ripping on half the plots. Year 1 establishment of all species was equal or lower on the graded versus graded\\/ripped plots. After 12

W. Clark Ashby

1996-01-01

207

Emerging drugs of abuse: current perspectives on substituted cathinones  

PubMed Central

Substituted cathinones are synthetic analogs of cathinone that can be considered as derivatives of phenethylamines with a beta-keto group on the side chain. They appeared in the recreational drug market in the mid-2000s and now represent a large class of new popular drugs of abuse. Initially considered as legal highs, their legal status is variable by country and is rapidly changing, with government institutions encouraging their control. Some cathinones (such as diethylpropion or pyrovalerone) have been used in a medical setting and bupropion is actually indicated for smoking cessation. Substituted cathinones are widely available from internet websites, retail shops, and street dealers. They can be sold under chemical, evocative or generic names, making their identification difficult. Fortunately, analytical methods have been developed in recent years to solve this problem. Available as powders, substituted cathinones are self-administered by snorting, oral injestion, or intravenous injection. They act as central nervous system stimulants by causing the release of catecholamines (dopamine, noradrenaline, and serotonin) and blocking their reuptake in the central and peripheral nervous system. They may also decrease dopamine and serotonin transporter function as nonselective substrates or potent blockers and may inhibit monoamine oxidase effects. Nevertheless, considerable differences have been found in the potencies of the different substituted cathinones in vitro. Desired effects reported by users include increased energy, empathy, and improved libido. Cardiovascular (tachycardia, hypertension) and psychiatric/neurological signs/symptoms (agitation, seizures, paranoia, and hallucinations) are the most common adverse effects reported. Severe toxicity signs compatible with excessive serotonin activity, such as hyperthermia, metabolic acidosis, and prolonged rhabdomyolysis, have also been observed. Reinforcing potential observed in animals predicts a high potential for addiction and abuse in users. In case of overdose, no specific antidote exists and no curative treatment has been approved by health authorities. Therefore, management of acute toxic effects is mainly extrapolated from experience with cocaine/amphetamines. PMID:24966713

Paillet-Loilier, Magalie; Cesbron, Alexandre; Le Boisselier, Reynald; Bourgine, Joanna; Debruyne, Daniele

2014-01-01

208

Strong infrared-to-visible frequency upconversion in Er 3+-doped Sr 2CeO 4 powders  

Microsoft Academic Search

Efficient upconversion (UC) luminescence is demonstrated in Er3+:Sr2CeO4 powders prepared by combustion synthesis and exposed to near-infrared (?975nm) radiation. The UC emission lines observed at ?530, ?550 and ?665nm correspond, respectively, to 2H11\\/2?4I15\\/2, 4S3\\/2?4I15\\/2 and 4F9\\/2?4I15\\/2 4f–4f transitions of Er3+. X-ray powder diffraction data showed that the SrCO3 phase (impurity) is dramatically reduced when Sr2+ is partially substituted by Mg2+

Nikifor Rakov; Renato B. Guimarães; Glauco S. Maciel

2011-01-01

209

Structure refinements of cadmium substituted lead fluoroapatites by powder X-ray pattern fitting  

NASA Astrophysics Data System (ADS)

Solid solutions of cadmium and lead fluoroapatite [Pb(10-x)Cdx(PO4)6F2 (0?x?5)] were synthesized by a wet process in a basic medium. Replacement of lead by cadmium induces a linear variation of the crystallographic parameters “a” and “c” according to Végard's law. The cadmium content, as obtained from the refinement, is in agreement with the chemical analysis. The distribution of the lead and cadmium ions between two non-equivalent crystallographic sites, M(1) and M(2), was determined by the Rietveld method. The site-occupancy factors of atoms clearly indicate a preference of cadmium for site M(1) in the apatite structure in agreement with its smaller ionic radii. A progressive shift of the F- ion toward the center of the triangles formed by the site M(2) metals has been observed with increasing cadmium content.

Badraoui, Béchir; Aissa, Abdallah; Debbabi, Mongi

2007-02-01

210

Air permeability of powder: A potential tool for Dry Powder Inhaler formulation development  

Microsoft Academic Search

Dry Powder Inhalers have drawn great attention from pharmaceutical scientists in recent years in particular those consisting of low-dose micronized drug particles associated with larger carrier particles and called interactive mixtures. However, there is little understanding of the relation between bulk powder properties such as powder structure and its aerodynamic dispersion performance. The aim of this work was to develop

V. N. P. Le; E. Robins; M. P. Flament

2010-01-01

211

Radio frequency (rf) plasma spheroidized HA powders: powder characterization and spark plasma sintering behavior  

Microsoft Academic Search

The present study describes the synthesis of spheroidized hydroxyapatite (HA) powders using a radio frequency (rf) inductively coupled plasma (ICP) torch. The spheroidized powders were consolidated through a spark plasma sintering (SPS) system. The microstructure and crystallographic phases in the synthesized powders were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD) and Raman spectrometry. Results

J. L. Xu; K. A. Khor; Y. W. Gu; R. Kumar; P. Cheang

2005-01-01

212

Service Substitution Revisited Dionysis Athanasopoulos  

E-print Network

that the client software is a Permission to make digital or hard copies of all or part of this work for personal issue: the complexity of the substitution process scales up with the number of avail- able services-oriented paradigm fosters the development of software consisting of basic architectural elements (a.k.a ser- vices

Paris-Sud XI, Université de

213

Solving Substitution Ciphers Sam Hasinoff  

E-print Network

Solving Substitution Ciphers Sam Hasinoff Department of Computer Science, University of Toronto Doyle's short story "The Adventure of the Dancing Men" (1903), the pro- tagonist Sherlock Holmes solves character. Figure 1: Dancing men ciphertext from "The Adventure of the Dancing Men" (1903). Thus, each

Toronto, University of

214

Thermoplastic dry polymer powder prepregging  

SciTech Connect

Thermoplastic resin systems have shown potential for reducing the manufacturing costs and improving the damage tolerance of composite structures. Current methods for thermoplastic resin impregnation of fiber bundles are limited by various difficulties and thus produce poor quality prepregs. The emerging technology of fiber is one of the most promising options, producing excellent matrix drape, and feasibility for a wide variety of matrix systems. An electrostatic dry polymer powder prepregging system was developed at the NSF Science and Technology Center at Virginia Tech, and has been used to produce high quality thermoplastic towpreg from a wide variety o polymer matrices. Additionally, a modification of the system allows for the production of towpreg from 15 gram polymer samples. This is ideal for the production of composites from resin systems under development, allowing early feedback concerning processing and composite mechanical performance.

Bucher, R.A.; Loos, A.C.; Meyer, G. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States)] [and others

1995-12-01

215

April 11, 2013 Powder Consolidation under Pressure  

E-print Network

Science and Technology. 2011;25:483-499 4. Alderborn G, Nystrom C. Pharmaceutical Powder Compaction generally formed by compression, is the most common pharmaceutical solid dosage form because of its economic Technology. 1996 5. Antikainen O, Yliruusi J. Determining the compression behavior of pharmaceutical powders

Thomas, David D.

216

Reaction Kinetics of Powdered Uranium and Deuteroammonia  

Microsoft Academic Search

A rate law for the nitridation of pyrophoric uranium with deuteroammonia was established for the entire course of the reaction. The rate of reaction between powdered uranium and deuteroammonia was determined to be a linear function of the initial Brunauer, Emmett, and Teller (BET) surface area and the fraction of unreacted uranium. Sintering of powdered uranium to a stable surface

R. M. Alire; J. H. McCrary

1966-01-01

217

A General Powder X-Ray Photography  

Microsoft Academic Search

AT the outset of calculation, no assumption whatever is made as to the symmetry and dimensions of the unit cell. The powder photograph is simply treated as that of a triclinic crystal without special relationship between its constants. The reflexion hkl in the powder photograph, then, may be expressed in terms of its reciprocal lattice1, thus: where theta is the

T. Ito

1949-01-01

218

Black Europeans  

NSDL National Science Digital Library

The British Library has been producing quality online features for close to a decade now, and this latest offering is worth a close look. This particular feature offers some insights and commentary on five prominent black Europeans. It may even come as a surprise to some visitors that several of the individuals profiled were black, such as Alexandre Dumas, the celebrated author of The Three Musketeers. These profiles are supplemented with essays by Dr. Mike Phillips, a writer, scholar, and journalist. The essays are accompanied by a series of images, including engravings, portraits, and illustrations. Visitors may also want to view and print out extended versions of Phillipsâ essays, which are available here in the pdf format.

219

Styryl dye coated metal oxide powders for the detection of latent fingermarks on non-porous surfaces.  

PubMed

Conventional fingermark powders rely on contrast induced by absorption/reflection (e.g. black powder) or luminescence in the visible region (e.g. Blitz Green(®)). In most cases, these powders provide sufficient contrast; however, in some circumstances surface characteristics can interfere with the visualisation of powdered fingermarks. Visualisation in the near infra-red (NIR) region, however, has been shown to eliminate interferences commonly encountered in the visible region. In this study, a mixture of rhodamine 6G and the NIR laser dye styryl 11 (STaR 11) was coated onto an aluminium oxide nanopowder and then mixed with silver magnetic powder to develop and visualise fingermarks in the NIR. When compared to Blitz Green(®), it was determined that the STaR 11 magnetic powder was better suited for marks deposited on textured surfaces and for older marks, whereas Blitz Green(®) performed better on smooth glossy surfaces. The ability of the STaR 11 mixed dye formulation to be visualised in both the visible and NIR regions also provides a significant advantage over conventional luminescent fingermark powders. PMID:22284074

Chadwick, Scott; Maynard, Philip; Kirkbride, Paul; Lennard, Chris; McDonagh, Andrew; Spindler, Xanthe; Roux, Claude

2012-06-10

220

Dense silica coatings on ceramic powder particles  

SciTech Connect

Dense silica coatings on the surface of inorganic powders particles are prepared by the hydrolysis of tetraethoxysilane (TEOS) in alcoholic suspensions. In a first reaction step, the TEOS is pre-hydrolysed in acidic solution and afterwards, a suspension of powder particles in this reaction solution is treated with ammonia which results in a dense silica coating of typically 10 - 100 nm thickness. Different luminescent powders which are used in the manufacture of cathode-ray tubes or fluorescent lamps have been coated by this procedure. The silica coating forms a transparent layer and the suspension properties of the coated powders are determined by the silica layer. The silica coating also protects sulfidic luminescent powders from being attacked by oxidizing agents like dichromate ions which are used in the suspension formulations for TV tube fabrication.

Opitz, J.F.A.; Mayr, W. [Philips GmbH Forschungslaboratorien, Aachen (Germany)

1995-09-01

221

New substituted amides and hydrazides of pectic acid  

SciTech Connect

Structural variants of pectin amides and hydrazides are of practical value as flocculants in water treatment. The purpose of this work was to further investigate the synthesis of substituted amides and hydrazides of pectic acid and to study their activity as flocculants. They used pectin, methylation products of pectin, pectic acid, and methyl pectates. The synthesized analogs of pectinic materials containing nitrogen are essentially copolymers of hydrazido (amido) and carboxyl (methoxyl) derivatives of D-galacturonic acid. The flocculant activity of the new polymers was monitored with simulated drainage water containing kaolin or abrasive powder (for glass manufacture) in the presence of polyvalent metal ions. The use of the new ampholytic flocculants in the purification of water from suspended impurities permits a high degree of clarification with a sharp decrease in reagent consumption.

Lapenko, V.L.; Potapova, L.B.; Slivkin, A.I.; Razumnaya, Z.A.

1988-05-10

222

Evaluation of suitable porosity for sintered porous {beta}-tricalcium phosphate as a bone substitute  

SciTech Connect

Structural and mechanical characterization is performed for sintered porous beta tricalcium phosphate ({beta}-TCP) to determine the appropriate porosity for use as a bone substitute. Four different types of porous {beta}-TCP specimen with different porosities are fabricated through a sintering process. For structural characterization, scanning electron microscopy and a Microfocus X-ray computed tomography system are used to investigate the pore openings on the specimen's surface, pore size, pore distribution, and pore interconnections. Compression tests of the specimens are performed, and mechanical properties such as the elastic modulus and compressive strength are obtained. Also, the geometric shape and volume of the {beta}-TCP around the contact region of two pores, which need to be initially resolved after implantation in order to increase the size of the pore openings, are evaluated through simple calculations. The results show that porous {beta}-TCP with 42.1% porosity may be a suitable bone substitute candidate in terms of sustaining external loads, and inducing and cultivating bone cells. - Highlights: Black-Right-Pointing-Pointer Structural and mechanical characterization was performed for sintered porous {beta}-TCP specimens. Black-Right-Pointing-Pointer For structural characterization, SEM and Microfocus X-ray CT system were used. Black-Right-Pointing-Pointer For mechanical characterization, compression tests were performed. Black-Right-Pointing-Pointer Porous {beta}-TCP with 42.1% porosity may be a suitable bone substitute.

Park, Jin-Hong; Bae, Ji-Yong [School of Mechanical Systems Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju, 500-757 (Korea, Republic of)] [School of Mechanical Systems Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju, 500-757 (Korea, Republic of); Shim, Jaebum [INJECTA Inc., 1511 Gwanyang-dong, Dongan-gu, Anyang-si, 431-809 (Korea, Republic of)] [INJECTA Inc., 1511 Gwanyang-dong, Dongan-gu, Anyang-si, 431-809 (Korea, Republic of); Jeon, Insu, E-mail: i_jeon@chonnam.ac.kr [School of Mechanical Systems Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju, 500-757 (Korea, Republic of)] [School of Mechanical Systems Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju, 500-757 (Korea, Republic of)

2012-09-15

223

Effect of nonindependent substitution on phylogenetic accuracy.  

PubMed

All current phylogenetic methods assume that DNA substitutions are independent among sites. However, ample empirical evidence suggests that the process of substitution is not independent but is, in fact, temporally and spatially correlated. The robustness of several commonly used phylogenetic methods to the assumption of independent substitution is examined. A compound Poisson process is used to model DNA substitution. This model assumes that substitution events are Poisson-distributed in time and that the number of substitutions associated with each event is geometrically distributed. The asymptotic properties of phylogenetic methods do not appear to change under a compound Poisson process of DNA substitution. Moreover, the rank order of the performance of different methods does not change. However, all phylogenetic methods become less efficient when substitution follows a compound Poisson process. PMID:12066710

Huelsenbeck, J P; Nielsen, R

1999-06-01

224

47 CFR 76.130 - Substitutions.  

Code of Federal Regulations, 2012 CFR

...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.130 Substitutions...syndicated program exclusivity, or sports blackout rules, a satellite...satellite carrier may, consistent with this Subpart, substitute...

2012-10-01

225

47 CFR 76.130 - Substitutions.  

Code of Federal Regulations, 2013 CFR

...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.130 Substitutions...syndicated program exclusivity, or sports blackout rules, a satellite...satellite carrier may, consistent with this Subpart, substitute...

2013-10-01

226

47 CFR 76.130 - Substitutions.  

Code of Federal Regulations, 2011 CFR

...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.130 Substitutions...syndicated program exclusivity, or sports blackout rules, a satellite...satellite carrier may, consistent with this Subpart, substitute...

2011-10-01

227

47 CFR 76.130 - Substitutions.  

Code of Federal Regulations, 2010 CFR

...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.130 Substitutions...syndicated program exclusivity, or sports blackout rules, a satellite...satellite carrier may, consistent with this Subpart, substitute...

2010-10-01

228

Skin Substitutes with Improved Barrier Function.  

National Technical Information Service (NTIS)

The present invention relates to in vitro cultured skin substitutes, and in particular to in vitro cultured skin substitutes that have improved barrier function. In some embodiments, improved barrier function is a result of improved culture conditions, wh...

A. Comer, L. A. Hoffmann, M. Hoffmann

2005-01-01

229

40 CFR 721.1643 - Benzenesulfonic acid, amino substituted phenylazo-.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Benzenesulfonic acid, amino substituted phenylazo-. 721... § 721.1643 Benzenesulfonic acid, amino substituted phenylazo-. ...generically as a benzenesulfonic acid, amino substituted phenylazo-...

2010-07-01

230

Smoking Cessation among Blacks.  

ERIC Educational Resources Information Center

Lung cancer is a serious health problem among blacks, with a mortality rate of 119 per 100,000 black males, compared to 81 per 100,000 for white males. Smoking cessation efforts are most successful when tailored to the black community, using black community networks and broadcast media for black audiences. (SLD)

Stotts, R. Craig; And Others

1991-01-01

231

Nucleotide Substitution Rates of HIV1  

Microsoft Academic Search

The molecular evolution of human immunodeficiency virus type 1 (HIV-1) is reviewed from the viewpoint of the rate of nucleotide substitution, which is defined as the number of nucleotide substitutions per site per year. The rate of nucleotide substitution is useful not only for estimating the origin and history of HIV-1 epidemics, but also for detecting natural selection operating at

Yoshiyuki Suzuki; Yumi Yamaguchi-Kabata; Takashi Gojobori

2000-01-01

232

A statistical framework for mining substitution rules  

Microsoft Academic Search

In this paper, a new mining capability, called mining of substitution rules, is explored. A substitution refers to the choice made by a customer to replace the purchase of some items with that of others. The mining of substitution rules in a transaction database, the same as that of association rules, will lead to very valuable knowledge in various aspects,

Wei-guang Teng; Ming-jyh Hsieh; Ming-syan Chen

2005-01-01

233

Expectations and Experiences of Substitute Teachers  

ERIC Educational Resources Information Center

This article explores the expectations of support for and the experiences of substitute teachers in an urban school division in Saskatchewan. Data were collected in semistructured interviews with seven substitute teachers. The purpose of the study was to explore how substitute teachers frame their professional experiences and construct their roles…

Duggleby, Patricia; Badali, Sal

2007-01-01

234

Structure, thermal expansion and electrical conductivity of Nb-substituted LaCoO{sub 3}  

SciTech Connect

The effect of Nb-substitution in LaCoO{sub 3} has been examined by evaluating the electrical conductivity, thermal expansion and crystal structure of the solid solutions LaCo{sub 1-x}Nb{sub x}O{sub 3} (x=0 to 1/3). It was demonstrated that Nb-substitution in LaCoO{sub 3} was mainly compensated by reduction of Co{sup 3+} to Co{sup 2+}, and that oxidation of Co{sup 2+} could destabilise the solid solution. The ambient crystal structure was shown to transform from rhombohedral R3{sup Macron }c perovskite (x=0) to orthorhombic Pbnm (x=0.15, 0.20) and finally to B-site ordered perovskite P2{sub 1}/n (x=0.25, 1/3) perovskite with increasing Nb-substitution. The thermal expansion of LaCo{sub 1-x}Nb{sub x}O{sub 3} was shown to be strongly depressed with increasing Nb-content, and significantly lower thermal expansion was observed for LaCo{sub 2/3}Nb{sub 1/3}O{sub 3} relative to LaCoO{sub 3}. The electrical conductivity was reduced with increasing Nb-content, and semi-conducting properties was demonstrated for LaCo{sub 1-x}Nb{sub x}O{sub 3} in contrast to the metallic behaviour of pure LaCoO{sub 3} at elevated temperature. The thermal expansion, electrical conductivity and the stability of the materials were discussed with emphasis on Co/Nb ordering, the oxidation state and spin transitions of Co. - Graphical abstract: Substitution of Nb in LaCoO{sub 3} increases the unit cell volume, reduces the symmetry of the unit cell and introduces cation ordering. The chemical substitution leads to suppression of the electronic conductivity and reduces the thermal expansion of the lattice. Highlights: Black-Right-Pointing-Pointer Cation ordering and crystal structure is reported for LaCo{sub x}Nb{sub 1-x}O{sub 3}. Black-Right-Pointing-Pointer Substitution of Nb in LaCoO{sub 3} is compensated by reduction of Co{sup 3+} to Co{sup 2+}. Black-Right-Pointing-Pointer Thermal expansion of LaCoO{sub 3} is reduced by Nb-substitution. Black-Right-Pointing-Pointer Electrical conductivity of LaCoO{sub 3} is reduced by Nb-substitution.

Oygarden, Vegar; Lein, Hilde L. [Department of Materials Science and Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Grande, Tor, E-mail: grande@ntnu.no [Department of Materials Science and Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway)

2012-08-15

235

Assessment of asbestos insulation substitutes  

SciTech Connect

A state-of-the-art study of asbestos insulation alternatives has been conducted to identify the best substitute material for steam lines in power plants. A survey of utilities across the nation showed that calcium silicate is the most commonly employed material today, followed by mineral wool, fiberglass, and ceramic fibers. However, the calcium silicate was found to be dusty and to become brittle once exposed to elevated temperatures. Although it is asbestos-free, studies on its carcinogenicity are incomplete. Characteristic data on existing substitute materials is compiled and an optimum choice of insulation combination is configured. Potential cost savings of using this combination is evaluated for a major utility. A PC-based computer program is developed to assist utility personnel in selecting the proper insulation materials for steam lines. 31 refs., 8 figs.

Fourroux, J.D.; Frank, R.L. Jr.; Newberry, T.W. Jr. (Tennessee Valley Authority, Chattanooga, TN (USA))

1990-03-01

236

Characterization of black pigment used in 30 BC fresco wall paint using instrumental methods and chemometry  

PubMed Central

Background and methods Several standard powdered black pigments were characterized by means of thermogravimetry TG-DTG and allied techniques. These pigments were used to make standard plaster frescoes at this purpose prepared. The latter ones were subjected to Raman and reflectance analysis. The results obtained, together with TG data, were chemometrically processed and used to identify an analogous standard fresco fabricated by an unknown commercial black pigment, obtaining excellent results. Results The same colorimetric and reflectometric techniques, coupled with suitable chemometric techniques, were then successfully used to identify the type of black pigment present in an ancient roman fresco of the Imperial Age (30 B.C.). Conclusion TG-DTG resulted useful techniques to autenticate powdered black pigments.Colorimetry and Raman, but also the only colorimetry, were useful to identify an ancient black pigment in situ. PMID:22594437

2012-01-01

237

A Comparison of Teachers', Administrators, and Substitute Teachers' Perceptions of Substitute Teachers'  

ERIC Educational Resources Information Center

A five category preference questionnaire was distributed to random samples of substitute teachers, regular teachers, and administrators. The data was analyzed using chi squared statistics. Substitutes rated principals' concern for substitute qualifications lower than did regular teachers and administrators. Substitutes also rated teachers lower in…

Trent, John H.; Ghilotti, Sharon

1972-01-01

238

Dynamic fragmentation of powders in spherical geometry  

NASA Astrophysics Data System (ADS)

Experimental evidence from a wide range of sources shows that the expanding cloud of explosively disseminated material comprises of "particles" or fragments which have different dimensions from those associated with the original material. Photographic evidence shows jets or fingers behind these expanding fragments. Powders and liquids have often been used to surround explosives to act as blast mitigants; this is the main driver for our research. Other examples of areas where these features are observed include fuel air explosives and enhanced blast explosives as well as quasi-static pressure mitigation systems. In this paper, we consider the processes occurring when an explosive interacts with a surrounding layer of powder in spherical geometry. Results from explosive experiments designed to investigate the effects of powder grain size and powder fill-to-burster charge mass ratio (/) are presented and compared with results from numerical modelling to explore what determines the primary fragment size distribution resulting from explosive dissemination of a layer of material and when this process begins. The evidence clearly shows that the process starts during the first wave transit period of the powder material and, despite the surrounding material initially being a loose powder, shows the characteristics of a brittle fracture mechanism. Later time video evidence shows the same number of jets or fingers as are identified by X-rays of the early, primary fragmentation process. The number of fragments is only a very weak function of the initial grain size of the powder.

Milne, A. M.; Floyd, E.; Longbottom, A. W.; Taylor, P.

2014-09-01

239

Monopole Black Hole Skyrmions  

E-print Network

Charged black hole solutions with pion hair are discussed. These can be used to study monopole black hole catalysis of proton decay. There also exist multi- black hole skyrmion solutions with BPS monopole behavior.

Ian G Moss; N Shiiki; E Winstanley

2000-05-02

240

Black Smokers  

NSDL National Science Digital Library

This webpage contains a brief introduction to the discovery of hydrothermal systems and black smokers. Within the webpage are links to information on gigantic tube worms, polychaete worms, oceans, and extreme environments. This site also provides a list of hydrothermal systems, relevant links to organizations, laboratories and observatories, WebQuests, and other websites with further information on hydrothermal systems. As part of the Environmental Literacy Council site, this webpage also contains links to other resources with environmental content, including air climate, land, water, ecosystems, energy, food, and environment and society.

2009-07-01

241

Formulation considerations for dry powder inhalers.  

PubMed

The market for inhalable dry powder medication has consistently grown over past years. Targeting the lungs has been recognized to offer several advantages compared with oral application of drugs. The successive development of inhalation products has led to advances in local treatment of different respiratory diseases, but has also demonstrated the possibility to utilize the lungs for systemic drug delivery. Since a dry powder inhalation product is always a combination of drug formulation and inhalation device, the requirements for the development of such a system may be particularly complex. Therefore, this review aims to give an overview of the necessary considerations for a successful dry powder inhaler development. PMID:25090281

Cordts, Eike; Steckel, Hartwig

2014-06-01

242

Investigation of the structural and microwave dielectric properties of mechanically alloyed Fe40Co60 powders  

NASA Astrophysics Data System (ADS)

Fe40Co60 powders were produced by mechanical Alloying (MA) route. Structural and microwave dielectric properties were investigated. Discussion of obtained results is conducted according to milling time. X-Ray powder Diffraction (XRD) shows that disordered ? (Fe40Co60) solid solution of substitution with body centered cubic (bcc) lattice is formed after 2h milling. Halder Wagner analysis reveals that least grain size of 15.59 nm and residual strain up to 0.8% are reached after 60h milling. The evolution of the Voigtian mixing factors according to milling progression confirms that structural properties are governed by residual strain accumulated during high- energy mechanical alloying (Gaussian profiles). Scanning Electron Microscopy (SEM) indicates that obtained powders adopt flattened angular shapes with high surface area. Microwave measurements are undertaken on bulk samples. High values of the dielectric permittivity depicting the conductive behavior of Fe-Co powders are measured. Dielectric permittivity spectra according to milling time shift towards higher values. Enhancement of the dielectric properties is related to the developed structure after milling.

Otmane, F.; Bergheul, S.; Triaa, S.; Azzaz, M.

2014-08-01

243

Hydrothermal synthesis and characterization of hydroxyapatite and fluorhydroxyapatite nano-size powders.  

PubMed

Pure hydroxyapatite (HAp) and fluoride-containing apatite powders (FHAp) were synthesized using a hydrothermal method. The powders were assessed by x-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM) and F-selective electrode. X-ray diffraction results revealed the formation of single phase apatite structure for all the compositions synthesized in this work. However, the addition of a fluoride ion led to a systematic shift in the (3 0 0) peak of the XRD pattern as well as modifications in the FTIR spectra. It was found that the efficiency of fluoride ion incorporation decreased with the increase in the fluoride ion content. Fluorine incorporation efficiency was around 60% for most of the FHAp samples prepared in the current study. Smaller and less agglomerated particles were obtained by fluorine substitution. The bioactivity of the powder samples with different fluoride contents was compared by performing cell proliferation, alkaline phosphatase (ALP) and Alizarin red staining assays. Human osteoblast cells were used to assess the cellular responses to the powder samples in this study. Results demonstrated a strong dependence of different cell activities on the level of fluoridation. PMID:20571182

Montazeri, Leila; Javadpour, Jafar; Shokrgozar, Mohammad Ali; Bonakdar, Shahin; Javadian, Sayfoddin

2010-08-01

244

Washing powders and the environment: has TAED any influence on the complexing behaviour of phosphonic acids?  

PubMed

Complexation properties of two phosphonic acids: nitrilotris (methylenephosphonic acid) and 1-hydroxyethane-1,1'-diphosphonic acid, with Cu(II) and Ca(II) have been previously determined by pH and ionic selective electrode titrations. These phosphonic acids are commonly added to washing powders as polyphosphate substitutes and are here studied in the presence of another detergent compound: tetraacetylethylenediamine (TAED), a bleaching activator. Product concentrations were chosen in order to correspond to component concentration ratios encountered in washing powders. Potentiometric titrations were carried out to determine the possible TAED interferences; they indicate that TAED and its by-products have no action on phosphonic acid complexing behaviour. Under our experimental conditions, the action of TAED was modelled with acetic acid and ethylenediamine, the final by-products of TAED hydrolysis. If we take into account both phosphonic and acetic acids, speciation diagrams corresponding to representative fresh water systems showed that the acetic acid does not influence cation speciation. PMID:12420935

Deluchat, Véronique; Lacour, Stella; Serpaud, Bernard; Bollinger, Jean-Claude

2002-10-01

245

Glass powder blended cement hydration modelling  

NASA Astrophysics Data System (ADS)

The use of waste materials in construction is among the most attractive options to consume these materials without affecting the environment. Glass is among these types of potential waste materials. In this research, waste glass in powder form, i.e. glass powder (GP) is examined for potential use in enhancing the characteristics of concrete on the basis that it is a pozzolanic material. The experimental and the theoretical components of the work are carried out primarily to prove that glass powder belongs to the "family" of the pozzolanic materials. The chemical and physical properties of the hydrated activated glass powder and the hydrated glass powder cement on the microstructure level have been studied experimentally and theoretically. The work presented in this thesis consists of two main phases. The first phase contains experimental investigations of the reaction of glass powder with calcium hydroxide (CH) and water. In addition, it includes experiments that are aimed at determining the consumption of water and CH with time. The reactivity, degree of hydration, and nature of the pore solution of the glass powder-blended cement pastes and the effect of adding different ratios of glass powder on cement hydration is also investigated. The experiments proved that glass powder has a pozzolanic effect on cement hydration; hence it enhances the chemical and physical properties of cement paste. Based on the experimental test results, it is recommended to use a glass powder-to-cement ratio (GP/C) of 10% as an optimum ratio to achieve the best hydration and best properties of the paste. Two different chemical formulas for the produced GP C-S-H gel due to the pure GP and GP-CH pozzolanic reaction hydration are proposed. For the pure GP hydration, the produced GP C-S-H gel has a calcium-to-silica ratio (C/S) of 0.164, water-to-silica ratio (H/S) of 1.3 and sodium/silica ratio (N/S) of 0.18. However, for the GP-CH hydration, the produced GP C-S-H gel has a C/S ratio of 1.17, H/S ratio of 2.5 and N/S ratio of 0.18. In the second phase of this research, theoretical models are built using a modified version of an existing cement hydration modelling code, "CEMHYD3D", to simulate the chemical reaction of the activated glass powder hydration and glass powder in cement. The modified model, which is referred to as the "MOD-model" is further used to predict the types, compositions and quantities of reaction products. Furthermore, the glass powder hydration data, which is obtained experimentally, is incorporated into the MOD-model to determine the effect of adding glass powder to the paste on the process of cement hydration and resulting paste properties. Comparisons between theoretical and experimental results are made to evaluate the developed models. The MOD-model predictions have been validated using the experimental results, and were further used to investigate various properties of the hydrated glass powder cement paste. These properties include, for example, CH content of the paste, porosity, hydration degree of the glass powder and conventional C-S-H and GP CS-H contents. The results show that the MOD-model is capable of accurately simulating the hydration process of glass powder-blended cement paste and can be used to predict various properties of the hydrating paste.

Saeed, Huda

246

Enhanced critical fields and superconducting properties of pre-doped B powder-type MgB2 strands  

NASA Astrophysics Data System (ADS)

Conventional doping methods that directly add C or a C-bearing species to Mg + B powder have the disadvantage of adding C inhomogeneously, yielding either under-reacted regions or, in some cases, secondary phases which may be either beneficial or detrimental. Alternatively, pre-doped B powder provides a more homogeneous distribution of the C dopant in MgB2. In this work, powders containing varying amounts of C were used to produce in situ MgB2 strands which showed high values of Bc2, Birr and transport Jc (104 A cm - 2 at 13.3 T). Compared to SiC-added and malic-acid-treated strands the pre-doped MgB2 showed high values of Birr primarily due to more efficient C substitution into the B sublattice and a concomitant increase in transport Jc.

Susner, M. A.; Yang, Y.; Sumption, M. D.; Collings, E. W.; Rindfleisch, M. A.; Tomsic, M. J.; Marzik, J. V.

2011-01-01

247

Synthesis and dielectric properties of substituted lanthanum aluminate  

SciTech Connect

LaAlO[sub 3] was chemically modified in order to ascertain the effects of substitution of larger cations on the compound's slight rhombohedral distortion from cubic symmetry--a property that often degrades the performance of LaAlO[sub 3] substrates for epitaxial high-temperature superconducting films. La[sub 1[minus]x]Sr[sub x]Al[sub 1[minus]x]Ti[sub x]O[sub 3] (x = 0.05, 0.10, 0.15, 0.25), La[sub 1[minus]x]Sr[sub x]Al[sub 1[minus]x]Zr[sub x]O[sub 3], La[sub 1[minus]x]Sr[sub x]Al[sub 1[minus]x]Mg[sub x]O[sub 3[minus]2x]F[sub 2x] and La[sub 1[minus]x]Sr[sub x]Al[sub 1[minus]x]Sc[sub x]O[sub 3[minus]x]F[sub x] (x = 0.05, 0.10, 0.15) were prepared in polycrystalline form and 1--2 mm single crystals of the Sr, Ti- and Sr,Zr-substituted systems were grown using a PbO-PbF[sub 2]-B[sub 2]O[sub 3]-PbO[sub 2] flux. Shifts in the peak positions of the X-ray powder diffraction patterns confirmed substitution of the larger cations. The diffraction patterns were also typified by line-broadening and a decrease in the rhombohedral splitting at all doping levels. The dielectric constant of LaAlO[sub 3] was unchanged for all of the fluoride-containing systems and for the 5% Sr,Ti- and Sr,Zr-systems.

Vanderah, T.A.; Lowe-Ma, C.K.; Gagnon, D.R. (Naval Air Warfare Center, China Lake, CA (United States))

1994-12-01

248

Laminated composite of magnetic alloy powder and ceramic powder and process for making same  

DOEpatents

A laminated composite structure of alternating metal powder layers, and layers formed of an inorganic bonding media powder, and a method for manufacturing same are discosed. The method includes the steps of assembling in a cavity alternating layers of a metal powder and an inorganic bonding media of a ceramic, glass, and glass-ceramic. Heat, with or without pressure, is applied to the alternating layers until the particles of the metal powder are sintered together and bonded into the laminated composite structure by the layers of sintered inorganic bonding media to form a strong composite structure. The method finds particular application in the manufacture of high performance magnets wherein the metal powder is a magnetic alloy powder.

Moorhead, Arthur J. (Knoxville, TN); Kim, Hyoun-Ee (Seoul, KR)

1999-01-01

249

Laminated composite of magnetic alloy powder and ceramic powder and process for making same  

DOEpatents

A laminated composite structure of alternating metal powder layers, and layers formed of an inorganic bonding media powder, and a method for manufacturing same are disclosed. The method includes the steps of assembling in a cavity alternating layers of a metal powder and an inorganic bonding media of a ceramic, glass, and glass-ceramic. Heat, with or without pressure, is applied to the alternating layers until the particles of the metal powder are sintered together and bonded into the laminated composite structure by the layers of sintered inorganic bonding media to form a strong composite structure. The method finds particular application in the manufacture of high performance magnets wherein the metal powder is a magnetic alloy powder. 9 figs.

Moorhead, A.J.; Kim, H.

1999-08-10

250

Continuous blending of dry pharmaceutical powders  

E-print Network

Conventional batch blending of pharmaceutical powders coupled with long quality analysis times increases the production cycle time leading to strained cash flows. Also, scale-up issues faced in process development causes ...

Pernenkil, Lakshman

2008-01-01

251

Hot Isostatic Pressing of Ceramic Powder Compacts.  

National Technical Information Service (NTIS)

The effect of temperature, pressure and time on the rate of densification of submicron alumina powder during hot isostatic pressing has been determined using a dilatometer to continuously monitor volumetric changes. A Fortran computer program is used to m...

J. K. McCoy, R. R. Wills

1984-01-01

252

Advances in beryllium powder consolidation simulation  

SciTech Connect

A fuzzy logic based multiobjective genetic algorithm (GA) is introduced and the algorithm is used to optimize micromechanical densification modeling parameters for warm isopressed beryllium powder, HIPed copper powder and CIPed/sintered and HIPed tantalum powder. In addition to optimizing the main model parameters using the experimental data points as objective functions, the GA provides a quantitative measure of the sensitivity of the model to each parameter, estimates the mean particle size of the powder, and determines the smoothing factors for the transition between stage 1 and stage 2 densification. While the GA does not provide a sensitivity analysis in the strictest sense, and is highly stochastic in nature, this method is reliable and reproducible in optimizing parameters given any size data set and determining the impact on the model of slight variations in each parameter.

Reardon, B.J.

1998-12-01

253

Metal powder production by gas atomization  

NASA Technical Reports Server (NTRS)

The confined liquid, gas-atomization process was investigated. Results from a two-dimensional water model showed the importance of atomization pressure, as well as delivery tube and atomizer design. The atomization process at the tip of the delivery tube was photographed. Results from the atomization of a modified 7075 aluminum alloy yielded up to 60 wt pct. powders that were finer than 45 microns in diameter. Two different atomizer designs were evaluated. The amount of fine powders produced was correlated to a calculated gas-power term. An optimal gas-power value existed for maximized fine powder production. Atomization at gas-power greater than or less than this optimal value produced coarser powders.

Ting, E. Y.; Grant, N. J.

1986-01-01

254

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2010 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive bronze powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2010-04-01

255

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2010 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive copper powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2010-04-01

256

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2010 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive aluminum powder shall...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2010-04-01

257

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2011 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive bronze powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2011-04-01

258

21 CFR 73.2645 - Aluminum powder.  

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive aluminum powder shall...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2014-04-01

259

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2013 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive bronze powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2013-04-01

260

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2013 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive aluminum powder shall...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2013-04-01

261

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2012 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive bronze powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2012-04-01

262

21 CFR 73.2646 - Bronze powder.  

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive bronze powder shall conform...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2014-04-01

263

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2011 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive aluminum powder shall...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2011-04-01

264

Electrosintering of iron powder compacts  

NASA Astrophysics Data System (ADS)

The influence of a nominal external electric fieldE=3 to 10 kV/cm on the sintering of iron powder compacts for 30 minutes at 1140°C in a vacuum of ˜10-6 torr was investigated. It was found that the field reduced the porosity by as much as 29 to 73 pct compared to sintering without a field, the magnitude depending on the procedure employed to measure the density of the specimen. Optical microscopy revealed that the specimen electrosintered withE=10 kV/cm had a skin of ˜0.2 mm in thickness, where the porosity was significantly less than in the interior. This was also the depth of carburization that was obtained upon carburizing the electrosintered specimens. It is proposed that the decrease in porosity produced by the field results from a decrease in the chemical potential of vacancies at or just below the charged external surface. Vacancy flux equations employed to calculate the porosity as a function of distance below the external surface showed that the porosity becomes approximately zero at a distance ofx c=0.4 to 0.5 mm below the surface, which is in reasonable accord with the microscopy measurements. Similar values ofx c were obtained by assuming that the entire porosity decrease given by the density measurements occurred in a ring of thickness ofx c below the external surface. The difference in the density measured by two Archimedes-principle procedures and microscopy observations suggests that the cavities open to the external surface of the electrosintered specimens are smaller or narrower than those for specimens sintered without a field.

Fahmy, Yusef; Conrad, Hans

2001-03-01

265

Advanced powder metallurgy aluminum alloys and composites  

NASA Technical Reports Server (NTRS)

The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

Lisagor, W. B.; Stein, B. A.

1982-01-01

266

Adjustable Powder Injector For Vacuum Plasma Sprayer  

NASA Technical Reports Server (NTRS)

Attachment for plasma spray gun provides four degrees of freedom for adjustment of position and orientation at which powder injected externally into plasma flame. Manipulator provides for adjustment of pitch angle of injection tube: set to inject powder at any angle ranging from perpendicular to parallel to cylindrical axis. Scribed lines on extension bar and manipulator indicate pitch angle of extension tube. Collar changed to adapt injector to different gun.

Burns, D. H.; Woodford, W. H.; Mckechnie, T. N.; Mcferrin, D. C.; Davis, W. M.; Beason, G. P., Jr.

1993-01-01

267

Energy approach to considering multicomponent powder systems  

NASA Astrophysics Data System (ADS)

The problems of formation of the structure of a dispersed multicomponent powder mixture in mixing are considered from an energy standpoint. The homogeneous state of a powder mixture is shown to be energetically more favorable than the state of its separation, since it has a lower free energy margin and a higher configurational entropy. Depending on external conditions, a mixture of homogeneous regions with different component concentrations can have a more stable state.

Minaev, A. M.; Mordasov, D. M.; Tyalina, L. N.

2013-11-01

268

Moisture sorption of Thai red curry powder  

Microsoft Academic Search

Moisture sorption study was conducted on Thai red curry powder prepared by two different drying methods, viz. microwave and hot-air drying. Moisture sorption isotherms of the red curry powder at 30 ?C and water activity in the range of 0.113-0.970 were determined by a static gravimetric method. The isotherms exhibited Type III behaviour. The moisture sorption data were fitted to

Sudathip Inchuen; Woatthichai Narkrugsa; Pimpen Pornchaloempong

269

Black Student Enrollment In Private Black Colleges  

Microsoft Academic Search

The purpose of this study was to determine the degree of knowledge that black high school students have regarding private historically black institutions of higher education in the State of Florida.An instrument was developed to measure this knowledge, the degree to which the students were informed about black colleges in their high schools and the factors affecting the race of

Anna Maria Price

1987-01-01

270

Fuel powder production from ductile uranium alloys.  

SciTech Connect

Metallic uranium alloys are candidate materials for use as the fuel phase in very-high-density LEU dispersion fuels. These ductile alloys cannot be converted to powder form by the processes routinely used for oxides or intermetallics. Three methods of powder production from uranium alloys have been investigated within the US-RERTR program. These processes are grinding, cryogenic milling, and hydride-dehydride. In addition, a gas atomization process was investigated using gold as a surrogate for uranium. Grinding was found to be inefficient and introduced impurities into the fuel. Cryogenic milling of machine chips in a steel vial was found to have similar shortcomings. The hydride-dehydride process has historically been used to produce very fine powder that may not be suitable for fuel fabrication. Uranium is made to form its hydride by heating in a hydrogen atmosphere. Subsequent heating under vacuum drives off hydrogen gas and returns the hydride to a metallic state. The volume change on hydride formation results in a fine powder upon dehydriding. The effects of alloying elements, partial hydriding, and subsequent milling treatments on particle size distribution are being explored. Inert gas atomization is used on an industrial scale to produce metal powder. Current designs are not suitable for use with uranium. A system was specifically designed for uranium atomization. A prototype was built and tested using gold as a surrogate for uranium. The system operates efficiently and can produce powder in a variety of size ranges by changing the atomization nozzle.

Clark, C. R.

1998-10-23

271

Ti Multicomponent Alloy Bulks by Powder Metallurgy  

NASA Astrophysics Data System (ADS)

In this study, CrCuFeMnMo0.5Ti multicomponent alloy bulks were prepared by powder metallurgy of mechanical alloying and sintering. A simple body-centered cubic (bcc) solid solution was prepared after 40 h ball milling of the raw CrCuFeMnMo0.5Ti metallic powder. Particles of the alloyed powder are in microsized structures, which are actually a soft agglomeration of lamellar grains with thicknesses less than 1 ?m. Meanwhile, the lamellar granules are consisted of nanosized grains under rigid cold welding. The 80-h ball-milled powder was consolidated by cold pressing and subsequent sintering at 800°C. The observed main phase in the consolidated sample after milling for 80 h is still a bcc solid solution. The solidified sample of 80-h ball-milled powder exhibits a Vickers hardness of 468 HV, which is much higher than 171 HV of the counterpart prepared from the raw metallic powder.

Zhang, Kuibao; Wen, Guanjun; Dai, Hongchuan; Teng, Yuancheng; Li, Yuxiang

2014-10-01

272

The basics of powder lubrication in high-temperature powder-lubricated dampers  

SciTech Connect

The objective of this investigation is to develop a novel powder-lubricated rotor bearing system damper concept for use in high-temperature, high-speed rotating machinery such as advanced aircraft gas turbine engines. The approach discussed herein consists of replacing a conventional oil lubrication or frictional damper system with a powder lubrication system that uses the process particulates or externally fed powder lubricant. Unlike previous work in this field, this approach is based on the postulate of the quasi-hydrodynamic nature of powder lubrication. This postulate is deduced from past observation and present verification that there are a number of basic features of powder flow in narrow interfaces that have the characteristic behavior of fluid film lubrication. In addition to corroborating the basic mechanism of powder lubrication, the conceptual and experimental work performed in this program provides guidelines for selection of the proper geometries, materials, and powders suitable for this tribological process. The present investigation describes the fundamentals of quasi-hydrodynamic powder lubrication and defines the rationale underlying the design of the test facility. The performance and the results of the experimental program present conclusions reached regarding design requirements as well as the formulation of a proper model of quasi-hydrodynamic powder lubrication.

Heshmat, H.; Walton, J.F. (Mechanical Technology Inc., Latham, NY (United States))

1993-04-01

273

tert-butyl-substituted cyclooctatetraenes  

Microsoft Academic Search

Reaction of cyclooctatetraene (COT) with tert-butyllithium provides a convenient synthesis of tert-butylcyclooctatetraene, 4. As a byproduct of the reaction mixture, 1,4-di-tert-butylcyclooctatriene has been isolated and converted to 1,4-di-tert-butylcyclooctatetraene, 5, by deprotonation with potassium amide and oxidation with iodine. An independent synthesis of 5 was developed from 9-oxabicyclo(6.1.0)octa-2,4,6-triene (cyclooctatetraene oxide), 9. The highly substituted compound 1,3,5,7-tetra-tert-butylcyclooctatetraene (6) has been prepared in

Michael J. Miller; Matthew H. Lyttle; Andrew Streitwieser

1981-01-01

274

Sensory substitution as an artificially acquired synaesthesia.  

PubMed

In this review we explore the relationship between synaesthesia and sensory substitution and argue that sensory substitution does indeed show properties of synaesthesia. Both are associated with atypical perceptual experiences elicited by the processing of a qualitatively different stimulus to that which normally gives rise to that experience. In the most common forms of sensory substitution, perceptual processing of an auditory or tactile signal (which has been converted from a visual signal) is experienced as visual-like in addition to retaining auditory/tactile characteristics. We consider different lines of evidence that support, to varying degrees, the assumption that sensory substitution is associated with visual-like experiences. We then go on to analyse the key similarities and differences between sensory substitution and synaesthesia. Lastly, we propose two testable predictions: firstly that, in an expert user of a sensory substitution device, the substituting modality should not be lost. Secondly that stimulation within the substituting modality, but by means other than a sensory substitution device, should still produce sensation in the normally substituted modality. PMID:22885223

Ward, Jamie; Wright, Thomas

2014-04-01

275

Biologic and synthetic skin substitutes: An overview.  

PubMed

The current trend of burn wound care has shifted to more holistic approach of improvement in the long-term form and function of the healed burn wounds and quality of life. This has demanded the emergence of various skin substitutes in the management of acute burn injury as well as post burn reconstructions. Skin substitutes have important roles in the treatment of deep dermal and full thickness wounds of various aetiologies. At present, there is no ideal substitute in the market. Skin substitutes can be divided into two main classes, namely, biological and synthetic substitutes. The biological skin substitutes have a more intact extracellular matrix structure, while the synthetic skin substitutes can be synthesised on demand and can be modulated for specific purposes. Each class has its advantages and disadvantages. The biological skin substitutes may allow the construction of a more natural new dermis and allow excellent re-epithelialisation characteristics due to the presence of a basement membrane. Synthetic skin substitutes demonstrate the advantages of increase control over scaffold composition. The ultimate goal is to achieve an ideal skin substitute that provides an effective and scar-free wound healing. PMID:21321652

Halim, Ahmad Sukari; Khoo, Teng Lye; Mohd Yussof, Shah Jumaat

2010-09-01

276

Black Box  

NSDL National Science Digital Library

In this activity students observe what happens when various amounts of water are poured into a black box and propose models to explain their observations. When water is poured into the funnel, students observe that sometimes water emerges through the outlet tube and sometimes it does not. Also, the amount of water that does emerge is not constant. Students share their initial ideas with others and offer criticism to peers. They prepare and present a poster of their final, revised models. The activity involves data collection, pattern recognition, and model building. Supplemental student activities, such as a pattern recognition activity and a model reading, are used to provide explicit instruction about individual components of model building and assessment. The site includes links to instructional notes, student activities, assessment, and student work examples.

277

Electrochemical studies of substituted spinel thin films  

SciTech Connect

Thin lithium manganese oxide spinel films, prepared with pulsed laser deposition have been used as a model system for the study of oxide electrochemical properties and performance degradation mechanisms in the absence of carbon or binder materials. Films (0.3 {micro}m) of Li{sub x}Mn{sub 2{minus}y}Me{sub y}O{sub 4}, where Me = Ni, Co and y = 0, 0.1, 0.25, were crystalline as-prepared. The cyclic voltammetric response as a function of oxide composition was measured in liquid electrolyte over the range of 2 to 5.8 V vs. Li/Li{sup +}. Quantitative analysis of the two 4 V peaks, for x > 0.5 and x < 0.5, correlated well with predicted film stoichiometry. The capacity of the 4.6 V redox peaks in the Ni-substituted films were consistent with the oxidation of Ni{sup 2+} to Ni{sup 4+}. No significant capacity was observed in LiMn{sub 2}O{sub 4} above 4.5 V. The shape of the voltammetric peaks in the 3 V region suggested that intercalation kinetics are slowed by the Jahn-Teller distortion, while all compositions in the 4 V region showed reversible behavior, except for the LiNi{sub 0.25}Mn{sub 1.75}O{sub 4} film which showed lower electronic conductivity. The LiMn{sub 1.90}Ni{sub 0.10}O{sub 4} films showed no loss in discharge capacity after being charged up to 5.7 V vs. Li/Li{sup +} with window-opening cyclic voltammetry. LiMn{sub 2}O{sub 4} and LiMn{sub 1.75}Co{sub 0.25}O{sub 4} films were stable to 5.6 and 5.4 V vs. Li/Li{sup +}, respectively. Explanations for the superior stability of the films relative to powder electrodes are examined.

Striebel, K.A.; Rougier, A.; Horne, C.R.; Reade, R.P.; Cairns, E.J.

1999-12-01

278

Lactose\\/?-Lactoglobulin Interaction During Storage of Model Whey Powders  

Microsoft Academic Search

The objective of this study was to evaluate the pres- ence or absence of interaction between lactose and ?- lactoglobulin during storage of model whey powders at different water activities (aw). Model whey powders were prepared by colyophilization of lactose with in- creasing quantities of ?-lactoglobulin. These colyophi- lized ?-lactoglobulin:lactose powders, assigned as BL powders, were stored from 0.11 to

M. E. C. Thomas; J. Scher; S. Desobry

2004-01-01

279

Dispersion of alkoxide-hydrolysed zirconia powders in aqueous suspensions  

Microsoft Academic Search

It is always desirable to control the agglomeration of ceramic powders in ceramic processing, as this strongly affects the sintering behaviour [1, 2] of the powders. A recent wet chemical process deserves attention because of the possibility of achieving ultrafine, high-purity monodispersed ceramic powders [3, 4] and the possibility of the powders obtained to yield ultrastructure [5]. During wet chemical

Kwang-Lung Lin; Huey-Chang Wang

1989-01-01

280

Tungsten Powder as an accelerator target & InBeam Testing  

E-print Network

: tungsten powder jet High speed image: tungsten powder flow in a pipe Dense-phase delivery Lean-phase lift - Reliability in harsh environment? - High static stress levels require much larger beam sigma than baseline) ­ Containment / erosion ­ Heat transfer and cooling of powder Unstable tungsten powder jet High speed image

McDonald, Kirk

281

Black Entrepreneurship in America.  

ERIC Educational Resources Information Center

The economic condition of black Americans is discussed, proceeding from the assumption that black economic progress does not depend on a renewed struggle for unobtained civil rights, but rather on the creative response of black Americans to economic opportunity and problems. In the long run, black economic development must rely on the…

Green, Shelley; Pryde, Paul

282

Frontal Dynamics of Powder Snow Avalanches  

NASA Astrophysics Data System (ADS)

We model the dynamics of the head of dilute powder snow avalanches sustained by a massive frontal blow-out, arising as a weakly cohesive snow cover is fluidized by the very pore pressure gradients that the avalanche induces within the snow pack. Such material eruption just behind the front acts as a source of denser fluid thrust into a uniform ambient air flow at high Reynolds number. In such "eruption current", fluidization depth is inversely proportional to a bulk Richardson number representing avalanche height. By excluding situations in which the snow cover is not fluidized up to its free surface, we derive a criterion combining snow pack friction and density indicating which avalanches can produce a sustainable powder cloud. A mass balance involving snow cover and powder cloud sets avalanche height and mean density. By determining which solution of the mass balance is stable, we find that avalanches reach constant growth and acceleration rates for fixed slope and avalanche width. Under these conditions, we calculate the fraction of the fluidized cover that is actually scoured and blown-out into the cloud, and deduce from a momentum balance on the head that the avalanche accelerates at a rate only 14% of the gravitational component along the flow. We also calculate how far a powder cloud travels until its mean density becomes constant. Finally, we show that the dynamics of powder snow avalanches are crucially affected by the rate of change of their width, for example by reaching an apparent steady speed as their channel widens. If such widening is rapid, or if slope inclination vanishes, we calculate where and how powder clouds collapse. Predictions agree well with observations of powder snow avalanches carried out at the Vallee de la Sionne (Switzerland).

Louge, M. Y.; Carroll, C. S.; Turnbull, B.

2012-04-01

283

[Medical mistakes due to generic substitution].  

PubMed

Generic substitution is a major cause of medical mistakes in the general population. Danish legislation obligates pharmacies to substitute prescribed medicine with the cheapest equivalent formulation, despite variations in product name, packaging, shape and colour. Consequently, medical mistakes occur. Scientific evidence on the consequences of generic substitution is sparse. Call upon fellow health workers to report medical mistakes to the national entities and scientific peers, in order to increase awareness and scientific evidence about the problem. PMID:22929573

Rölfing, Jan Hendrik Duedal

2012-08-27

284

Nucleophilic vinylic substitutions of ? 3-vinyliodanes  

Microsoft Academic Search

Because of the excellent nucleofugality of the ?3-phenyliodanyl group, which shows a leaving group ability about 106 times greater than triflate, ?3-vinyl(phenyl)iodanes serve as highly reactive species in nucleophilic substitutions. This review summarizes the nucleophilic vinylic substitutions of ?3-vinyl(phenyl)iodanes. The reaction rates and mechanism of the nucleophilic vinylic substitutions change depending on the structure of ?3-vinyliodanes; the nature of the

Masahito Ochiai

2000-01-01

285

Large-scale and shape-controlled synthesis and characterization of nanorod-like nickel powders under microwave radiation  

SciTech Connect

Graphical abstract: The nanorod-like pure nickel were fabricated via hydrothermal liquid phase reduction route under microwave irradiation with hydrazine hydrate as a reducing agent as well as polyvinyl alcohol as a dispersant and/or structure directing agent. The materials were characterized by XRD, SEM, EDS, HRTEM, and selected-area electron diffraction, etc. The lattice expansion for Ni powders was explained in detail. As-prepared Ni sample was of obvious shape anisotropy with length diameter ratio of 5. Magnetic measurements shown that the magnetic properties of Ni nanorod-like (fcc) were quite different from those of hexagonal closed-packed (hcp) Ni nanoparticles. Highlights: Black-Right-Pointing-Pointer The synthesis of nanorod-like nickel under microwave irradiation. Black-Right-Pointing-Pointer Nitrogen generated in reaction as a shielding gas. Black-Right-Pointing-Pointer The lattice expansion for Ni powders was explained in detail. Black-Right-Pointing-Pointer Magnetic properties of Ni were quite different from those of Ni nanoparticles. -- Abstract: The nanorod-like nickel powders were fabricated via hydrothermal liquid phase reduction route under microwave irradiation with hydrazine hydrate as a reducing agent as well as polyvinyl alcohol as a dispersant and/or structure directing agent. The morphology and structure of as-prepared products could be easily tuned by adjusting process parameters such as pH value and microwave irradiation time. The resulting materials were characterized by X-ray diffraction (XRD), scanning electron microscope, transmission electron microscopy and selected-area electron diffraction (SAED). The results demonstrated that pure nickel powders with face-centered cubic (fcc) structure were prepared at relatively mild condition and no characteristic peaks of nickel oxide in the XRD pattern were found. The phenomenon of lattice expansion for Ni powders was explained in details according to the XRD theory. As-prepared Ni sample was of obvious shape anisotropy with length diameter ratio of 5. Magnetic measurements shown that the magnetic properties of nanorod-like (fcc) Ni powders were quite different from those of hexagonal closed-packed (hcp) Ni nanoparticles. Furthermore, it had more strong ferromagnetic properties than that of Ni powders both bulk and nanoparticles.

Guo, Yajie [School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China)] [School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China); Wang, Guangjian, E-mail: wgj2260@chnu.edu.cn [School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China)] [School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China); Wang, Yuran [School of Chemistry and Chemical Engineering, Shanghai Jiaotong University, Shanghai 200030 (China)] [School of Chemistry and Chemical Engineering, Shanghai Jiaotong University, Shanghai 200030 (China); Huang, Yanhong [School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China)] [School of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, Anhui (China); Wang, Fei [School of Chemistry and Chemical Engineering, Shanghai Jiaotong University, Shanghai 200030 (China)] [School of Chemistry and Chemical Engineering, Shanghai Jiaotong University, Shanghai 200030 (China)

2012-01-15

286

Mechanistic studies on iridium catalyzed allylic substitution.  

E-print Network

??Mechanistic studies on iridium catalyzed allylic substitution reactions catalyzed by iridium phosphoramidite complexes revealed that the active catalyst is generated through a base assisted cyclometalation… (more)

Madrahimov, Sherzod

2012-01-01

287

47 CFR 76.110 - Substitutions.  

Code of Federal Regulations, 2010 CFR

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.110 Substitutions...community unit may, consistent with these rules and the sports blackout rules at §...

2010-10-01

288

47 CFR 76.110 - Substitutions.  

Code of Federal Regulations, 2012 CFR

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.110 Substitutions...community unit may, consistent with these rules and the sports blackout rules at §...

2012-10-01

289

47 CFR 76.110 - Substitutions.  

Code of Federal Regulations, 2011 CFR

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.110 Substitutions...community unit may, consistent with these rules and the sports blackout rules at §...

2011-10-01

290

47 CFR 76.110 - Substitutions.  

Code of Federal Regulations, 2013 CFR

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) ...Syndicated Exclusivity and Sports Blackout § 76.110 Substitutions...community unit may, consistent with these rules and the sports blackout rules at §...

2013-10-01

291

Polycyclic Aromatic Triptycenes: Oxygen Substitution Cyclization Strategies  

E-print Network

The cyclization and planarization of polycyclic aromatic hydrocarbons with concomitant oxygen substitution was achieved through acid catalyzed transetherification and oxygen-radical reactions. The triptycene scaffold ...

VanVeller, Brett

292

Fundamentals of Powder Compression. I. The Compactibility and Compressibility of Pharmaceutical Powders  

Microsoft Academic Search

In spite of the widespread use of tablets, the theoretical understanding of the tableting process has been limited. During the last decades considerable research has been done in the field of powder technology and compaction. A survey of the literature and compression equations reveals many studies on the characterization of powder properties, most of which relate to volume reduction under

Hans Leuenberger; Bhagwan Dass Rohera

1986-01-01

293

Synthesis of La-Co Substituted M-type Calcium Hexaferrite by Polymerizable Complex Method  

NASA Astrophysics Data System (ADS)

Synthesis of La-Co substituted M-type Calcium hexaferrite was studied. Samples were prepared by polymerizable complex method. High purity reagent of strontium carbonate, iron (III) nitrate ennnahydrate, cobalt (II) nitrate hexahydrate and lanthanum oxide were used as starting materials. Prepared aqueous solution was heated for dehydration and gelling. Thermal pyrolysis was carried out by heating the gel. The obtained precursor powders were ground with an alumina mortar and compacted by uniaxial pressing into disk specimens and then heated at temperature range between 1173 K and 1573 K in air. Phase identification and determination of lattice parameters were carried out by powder X-ray diffraction (XRD). Scanning Electron Microscope (SEM) was utilized to investigate the microstructure of the polycrystalline ferrites. Magnetic properties were discussed by magnetization measurements by measuring of M-H curve with vibrating sample magnetometer (VSM). Single-phase of M-type hexaferrite was obtained at lower temperature relative to by conventional synthesis.

Kikuchi, T.; Nakamura, T.; Yamasaki, T.; Nakanishi, M.; Fujii, T.; Takada, J.; Ikeda, Y.

2011-10-01

294

Evaluation of antioxidant, rheological, physical and sensorial properties of wheat flour dough and cake containing turmeric powder.  

PubMed

The effects of addition of turmeric powder (0%, 2%, 4%, 6% and 8%) were examined in order to obtain an antioxidant-enriched cake with good physico-chemical and sensorial properties. The rheological properties of doughs were evaluated using dynamic rheological measurements. Physical properties, curcumin content, radical scavenging activity (RSA-DPPH assay) and sensory analysis (hedonic test) of the supplemented cake were determined. Addition of turmeric powder up to 8% caused significant changes on dough characteristics and on cake rheological properties. The highest curcumin (203?mg/kg) and RSA-DPPH activity (45%) were achieved in the cake having the highest percentage of turmeric powder (8%); however, this sample showed the worst results regarding the rheological properties. Moreover, by sensory evaluation this cake sample was not acceptable. A 6% substitution of wheat flour with turmeric powder showed acceptable sensory scores which were comparable to those of 0-4% turmeric cakes. This indicated that up to 6% level of turmeric powder might be included in cake formulation. PMID:23144239

Park, S H; Lim, H S; Hwang, S Y

2012-10-01

295

Slip Casting of ?-Sialon/AlN/BN Powder Carbothermally Prepared by Boron-rich Slag-based Mixture  

NASA Astrophysics Data System (ADS)

With boron-rich slag, silica fume, bauxite chalmette and carbon black as starting materials, ?-Sialon/AlN/BN powder was prepared by carbothermal reduction-nitridation. The powder was attrition milled to submicron size and suspended in water. The effects of yttrium oxide as a sintering aid, pH, and addition of deflocculant on the suspensions were study. Optimum slip casting properties, i.e. lowest viscosity values, the highest absolute zeta potential values, the smallest floc size and sediment volume were found at pH 10 for the powder. The suspensions were used to slip cast discs which were sintered in a nitrogen atmosphere at 1700°C for 2h. The strength was about 230MPa, the toughness 3.6 MPa·m1/2 and the hardness about 13.8GPa.

Jun-bin, Wu; Xiang-xin, Xue; Tao, Jiang; Qing, Zhang

2011-10-01

296

Die-target for dynamic powder consolidation  

DOEpatents

A die/target is disclosed for consolidation of a powder, especially an atomized rapidly solidified metal powder, to produce monoliths by the dynamic action of a shock wave, especially a shock wave produced by the detonation of an explosive charge. The die/target comprises a rectangular metal block having a square primary surface with four rectangular mold cavities formed therein to receive the powder. The cavities are located away from the geometrical center of the primary surface and are distributed around such center while also being located away from the geometrical diagonals of the primary surface to reduce the action of reflected waves so as to avoid tensile cracking of the monoliths. The primary surface is covered by a powder retention plate which is engaged by a flyer plate to transmit the shock wave to the primary surface and the powder. Spawl plates are adhesively mounted on other surfaces of the block to act as momentum traps so as to reduce reflected waves in the block. 4 figs.

Flinn, J.E.; Korth, G.E.

1985-06-27

297

Material substitution and path dependence: empirical evidence on the substitution of copper for aluminum  

Microsoft Academic Search

Adopting an evolutionary perspective, this paper argues that path dependence plays a major role in material use and substitution such that it might delay or even prevent substitution despite the occurrence of significant relative price changes. After elucidating the importance of material substitution from an ecological-economic point of view and after explaining the meaning of path dependence from an evolutionary

Frank Messner

2002-01-01

298

Dry powder coating of pharmaceuticals: a review.  

PubMed

Over the last half century, film coating technology has evolved significantly in terms of compositions and manufacturing processes, allowing for greater functionality, flexibility and efficiency. Driven by a combination of cost considerations and functionality, a range of dry powder coating technologies have been developed in both academic and industrial settings. These technologies can be generally classified into three major types based on the layer formation process: liquid assisted, thermal adhesion and electrostatic. In addition to specific manufacturing processes that must be implemented to achieve the desired product attributes, many of these techniques also require the use of novel excipients and specific formulations to provide acceptable manufacturability. This review summarizes the current dry powder coating technologies and highlights their industrial applicability with publicly disclosed case studies. Commentary on the future directions of dry powder coating is also provided. PMID:23428881

Sauer, Dorothea; Cerea, Matteo; DiNunzio, James; McGinity, James

2013-12-01

299

Reactive plasma atomization of aluminum nitride powder  

SciTech Connect

Experiments were performed to synthesize AlN powders by reacting Al with N using a conventional dc arc plasma as heat source. Feeding Al powder into Ar/N plasma open to atmosphere produced mainly Al oxide. Experiments using a chamber backfilled with nitrogen suppressed the Al oxide, but little AlN was formed. A furnace and crucible assembly was designed to feed molten Al directly into a DeLaval nozzle attached to the face of the dc arc plasma gun. Resulting submicron powders show a significant increase in AlN formation. This was dependent on chamber pressure, plasma velocity, and molten liquid feed rate. Experimental parameters, equipment design, effects of atomization/vaporization/condensation are discussed.

Prichard, P.; Besser, M.; Sordelet, D.; Anderson, I.

1997-02-01

300

Quantum Black Holes. Black Hole Temperature without a Black Hole  

E-print Network

The model is constructed, some features of which comes from quantum thin dust shells and is, in fact, an extension of the "no hair" property of classical black hole on a quantum level. It appears that the proposed classical analog of quantum black hole is heated, the temperature being exactly the Hawking's temperature.

Victor Berezin

2008-12-24

301

Toxicity of Lead and Proposed Substitute Shot to Mallards  

USGS Publications Warehouse

Poisoning of North American waterfowl resulting from the ingestion of lead shot by ducks, geese, and swans causes an estimated annual mortality of 2 to 3% of the population (Bellrose 1959). To alleviate this problem the search for a suitable substitute for lead has been underway since the early 1950's. Proposed substitutes for lead shot were evaluated in a series of acute toxicity tests with pen-reared mallards (Anas platyrhynchos). Most candidate materials were as toxic to ducks as commercial lead shot. Coating or alloying lead with other metals only delayed mortality among dosed ducks. The reputedly 'disintegrable' lead shot with the water-soluble binder and the lead containing biochemical additives were also as toxic to mallards as the commercial lead shot. Mortality was not significantly different among lead-dosed adult or first-year hen and drake pen-reared mallards; lead-dosed adult, wild mallards of both sexes; and lead-dosed adult, male black ducks (Anas rubripes). The ingestion of one lead shot, size 4, by each of 80 pen-reared mallards caused an average 19% mortality. The presence and type of grit in the gizzard had a measurable effect on erosion of ingested shot and on shot retention among dosed mallards. Significantly fewer lead-dosed ducks died when fed crushed oystershell grit than when fed either quartz grit or no grit.

Longcore, J.R.; Andrews, R.; Locke, L.N.; Bagley, G.E.; Young, L.T.

1974-01-01

302

Giant Enhancement in the Physical Properties of LaFeO3 by Substitution of Divalent Ions  

NASA Astrophysics Data System (ADS)

Perovskites with the general formula La1-xMxFeO3, x = 0.0 and x = 0.3, M = Ca2+, Sr2+ and Ba2+ were prepared by the double sintering ceramic technique. The X-ray powder diffraction, IR and TEM were carried out to characterize the samples. The molar magnetic susceptibility (?M) was enhanced by substitution the divalent metal ion (M2+ = Ca2+, Sr2+ and Ba2+) instead of La+3. The saturation magnetization for both Ca2+ and Sr2+ substituted samples is increased up to 10 times its values for the parent which allow to use these samples in many applications. The Ca substitution improves the conductivity by more than 18 times while the Sr enhances it by 25 times.

Ahmed, M. A.; Dek, S. I.; Arman, M. M.

2013-03-01

303

Mineral, chemical and radiological investigation of a black sand at Touzla Cape, near Thessaloniki, Greece  

Microsoft Academic Search

A black-sand formation located at Touzla Cape, near Thessaloniki city, Greece, was investigated using optical microscopy, powder-XRD, SEM-EDS, INAA and in-situ G-ray spectrometry. This black sand is mainly composed of ilmenite, magnetite, garnet, zircon and rutile. Also present, in minor or trace amounts, are quartz, sphene, pyroxenes, sillimanite, feldspars, biotite, haematite, tourmaline, chromite, niobian-rutile and pyrrhotite. Niobian-rutile and pyrrhotite were

Anestis Filippidis; Panagiotis Misaelides; Alexander Clouvas; Athanasios Godelitsas; Nikolaos Barbayiannis; Ioannis Anousis

1997-01-01

304

Synthesis of ultrafine powders by microwave heating  

DOEpatents

A method of synthesizing ultrafine powders using microwaves is described. A water soluble material is dissolved in water and the resulting aqueous solution is exposed to microwaves until the water has dissolved. The resulting material is an ultrafine powder. This method can be used to make Al/sub 2/O/sub 3/, NiO /plus/ Al/sub 2/O/sub 3/ and NiO as well as a number of other materials including GaBa/sub 2/Cu/sub 3/O/sub x/. 1 tab.

Meek, T.T.; Sheinberg, H.; Blake, R.D.

1987-04-24

305

Removing Undesired Fine Powder From Silicon Reactor  

NASA Technical Reports Server (NTRS)

Fluidized-bed reactor produces highly pure polycrystalline silicon particles with diameters approximately greater than 400 micrometers. Operates by pyrolysis of silane in reaction zone, which is bed of silicon seed particles fluidized by flow of silane and carrier gas. Above reaction zone, gas mixture flows rapidly enough to entrain silicon powders, but not larger seed and product particles. Entrained particles swept out of reactor. Applicable to other processes such as production of fine metal and ceramic powders where control of sizes of product needed.

Flagella, Robert N.

1992-01-01

306

Alternative carriers in dry powder inhaler formulations.  

PubMed

The aerosolization efficiency of a powder is highly dependent on carrier characteristics, such as particle size distribution, shape and surface properties. The main objective in the inhalation field is to achieve a high and reproducible pulmonary deposition. This can be provided by successful carrier selection and careful process optimization for carrier modification. Lactose is the most common and frequently used carrier in dry powder inhaler (DPI) formulations. But lactose shows some limitations in formulation with certain drugs and peptides that prohibit its usage as a carrier in DPI formulations. Here, we criticality review the most important alternative carriers to lactose with merits, demerits and applications in DPI formulations. PMID:24269834

Rahimpour, Yahya; Kouhsoltani, Maryam; Hamishehkar, Hamed

2014-05-01

307

Synthesis of ultrafine powders by microwave heating  

DOEpatents

A method of synthesizing ultrafine powders using microwaves is described. A water soluble material is dissolved in water and the resulting aqueous solution is exposed to microwaves until the water has been removed. The resulting material is an ultrafine powder. This method can be used to make Al.sub.2 O.sub.3, NiO+Al.sub.2 O.sub.3 and NiO as well as a number of other materials including GaBa.sub.2 Cu.sub.3 O.sub.x.

Meek, Thomas T. (Knoxville, TN); Sheinberg, Haskell (Los Alamos, NM); Blake, Rodger D. (Santa Fe, NM)

1988-01-01

308

Efficient Cryptanalysis of Homophonic Substitution Amrapali Dhavare  

E-print Network

technique to the "Zodiac 340" cipher, which is an unsolved message created by the infamous Zodiac killer was created by the infamous Zodiac killer in 1969 [5]. Another Zodiac cipher, the "Zodiac 408. Keywords: homophonic substitution cipher, simple substitution cipher, hill climb, heuristic search, Zodiac

Stamp, Mark

309

Substitute Teachers: Making Lost Days Count  

ERIC Educational Resources Information Center

As K-12 teachers and administrators grow increasingly concerned with issues of accountability, research-based methods, and intervention strategies, little discussion exists on the impact of substitute teachers in the classroom. In the rush to analyze test scores, are the days covered by substitute teachers even considered? Though districts are…

True, Charlene; Butler, Kyle; Sefton, Rachel

2011-01-01

310

Allogeneic skin substitutes applied to burns patients  

Microsoft Academic Search

Early re-surfacing of burn wounds remains the ideal but is limited by the availability of skin graft donor sites. Cultured grafts overcome these problems and autologous keratinocytes can be grown in culture and placed on a dermal substitute, but this results in delay and requires two operations. We developed an organotypic skin substitute, which achieves cover in one procedure, and

J. Nanchahal; R. Dover; W. R. Otto

2002-01-01

311

Aromatic nucleophilic substitutions under microwave irradiation  

Microsoft Academic Search

In order to study the effect of microwave irradiation over aromatic nucleophilic substitutions at atmospheric pressure and in a homogeneous medium, experiments with disubstituted-benzenes and the nucleophiles piperidine and potassium t-butoxide, in refluxing DMSO or DMF, were carried out. The aromatic nucleophilic substitutions under microwave irradiation were 2.7 to 12 times faster than under conventional reflux.

Gean V. Salmoria; Evandro Dall'Oglio; César Zucco

1998-01-01

312

Educators Take Another Look at Substitutes  

ERIC Educational Resources Information Center

The mythology surrounding the substitute teacher is not a pretty one: Paper airplanes, lost learning, bullying. But as schools collect more information about teacher absenteeism and its consequences, districts and schools are exploring ways to professionalize substitute teaching--or experiment with alternative ways of coping with teacher absences.…

Zubrzycki, Jaclyn

2012-01-01

313

Effect of pressure on bonding in black phosphorus  

Microsoft Academic Search

The bond lengths and bond angles of orthorhombic black phosphorus have been determined as a function of hydrostatic pressures to 26.6(5) kbar using time-of-flight neutron powder diffraction. We show that the markedly anisotropic compression reported previously results from a large pressure-induced shortening of the van der Waals bonds separating layers of atoms combined with a shear motion within the layers.

L. Cartz; S. R. Srinivasa; R. J. Riedner; J. D. Jorgensen; T. G. Worlton

1979-01-01

314

High-temperature resistivity and thermoelectric properties of coupled substituted Ca3Co2O6  

NASA Astrophysics Data System (ADS)

Polycrystalline samples of Ca3-xNaxCo2-xMnxO6 (x=0.0-0.5) have been prepared by the sol-gel cum combustion method using sucrose in order to investigate the effects of the coupled substitution of Na and Mn on Ca and Co sites on the transport properties of Ca3Co2O6(Co326). The products were characterized by Fourier transform infrared spectroscopy, powder x-ray diffraction (XRD), thermogravimetry (TGA), differential thermal analysis and scanning electron microscopy. XRD patterns reveal the formation of single-phase products up to x=0.5. Coupled substitution increases the solubility of both Na and Mn on Ca and Co sites, respectively, in contrast to the limited solubility of Na and Mn (x=0.2) when separately substituted. TGA confirms the formation of the Ca3Co2O6 phase at temperatures ~720 °C. The grain size of the parent and substituted products is in the range 150-250 nm. Electrical resistivity and Seebeck coefficient were measured in the temperature range 300-800 K. Resistivity shows semiconducting behavior for all the compositions, particularly in the low-temperature regime. The Seebeck coefficient increases with temperature throughout the measured temperature range for all compositions. The maximum Seebeck coefficient (200 ?V K-1) is observed for x=0.5 at 825 K, and this composition may be optimal for high-temperature thermoelectric applications.

Senthilkumar, Meenakshisundaram; Vijayaraghavan, Rajagopalan

2009-01-01

315

Magnetic Properties of Amorphous Fe-Si-B Powder Cores Mixed with Pure Iron Powder  

NASA Astrophysics Data System (ADS)

Amorphous Fe-Si-B alloy was prepared by melt-spinning, and then the ribbons were pulverized and ball-milled to make the amorphous powder of ˜25 µm in size. Subsequently those were mixed with pure iron powders with an average particle size of 3 µm, and 1.5 wt % water glass diluted by distilled water at the ratio of 1:2. The powder mixtures were cold compacted at 650 MPa in toroid die, and heat treated at 430-440 °C under a nitrogen atmosphere for 1 h and 30 min, respectively. The soft magnetic properties of powder core were investigated using a B-H analyzer and a flux meter at the frequency range of ˜100 kHz. The microstructure was observed using scanning electron microscope (SEM), and the density of the core was measured using the principle of Archimedes. Based on the experimental results, the amorphous powder mixed with pure iron powder showed the improved powder compactability, which resulted in the increased permeability and the reduced core loss.

Kim, Hyeon-Jun; Nam, Seul Ki; Kim, Kyu-Sung; Yoon, Sung Chun; Sohn, Keun-Yong; Kim, Mi-Rae; Sul Song, Yong; Park, Won-Wook

2012-10-01

316

Mixing of zeolite powders and molten salt  

Microsoft Academic Search

Transuranics and fission products in a molten salt can be incorporated into zeolite A by an ion exchange process and by a batch mixing or blending process. The zeolite is then mixed with glass and consolidated into a monolithic waste form for geologic disposal. Both processes require mixing of zeolite powders with molten salt at elevated temperatures (>700 K). Complete

C. Pereira; V. N. Zyryanov; M. A. Lewis; J. P. Ackerman

1996-01-01

317

Pourability Enhancement of PETN Explosive Powders  

SciTech Connect

Manufacture of precision detonators requires the pelletizing of very fine, organic, crystalline explosive powders. Production of pellets in automatic machines within critical dimensional and weight tolerances requires that the powders pour uniformly into die cavities. The pellets must be able to be initiated with low energy and have a predictable energy output. Modifications to needle-like crystalline PETN explosive powders to make them pourable were introduced by the application of about 80 A thick polymeric coatings to the individual crystals, followed by a controlled agglomeration into a spherical prill. Microencapsulation techniques provided the key to achieving the result using less than 0.5 wt. % coating (an order of magnitude less coating than in usual PBX systems). These coatings did not appreciably alter the energy required to initiate and significantly increased the strength of the pellets. A key point demonstrated, which may be translated to other applications, was that powders that exhibit performance based on physical characteristics could have their handling and strength properties tailored with little change in their primary function.

Vannet, M.D.; Ball, G.L.

1987-01-01

318

MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON  

EPA Science Inventory

The paper presents a mathematical model of total mercury removed from the flue gas at coal-fired plants equipped with powdered activated carbon (PAC) injection for Mercury control. The developed algorithms account for mercury removal by both existing equipment and an added PAC in...

319

Magnetic properties of dispersed magnetite powders  

Microsoft Academic Search

Measurements have been made of coercive force, susceptibility, isothermal remanence, thermoremanence and thermal and alternating field demagnetization of annealed magnetite powders in nine size ranges from 1·5 ? to 120 ?. The samples were dispersed in plaster to occupy a few per cent by volume of the specimens and thus to simulate the magnetic properties of rocks. The results are

L. G. Parry

1965-01-01

320

Powder-Metallurgy Process And Product  

NASA Technical Reports Server (NTRS)

Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

Paris, Henry G.

1988-01-01

321

Laboratory Powder Metallurgy Makes Tough Aluminum Sheet  

NASA Technical Reports Server (NTRS)

Aluminum alloy sheet exhibits high tensile and Kahn tear strengths. Rapid solidification of aluminum alloys in powder form and subsequent consolidation and fabrication processes used to tailor parts made of these alloys to satisfy such specific aerospace design requirements as high strength and toughness.

Royster, D. M.; Thomas, J. R.; Singleton, O. R.

1993-01-01

322

High-Performance Polyimide Powder Coatings  

NASA Technical Reports Server (NTRS)

Researchers at NASA's Kennedy Space Center have developed advanced powder coatings for longer-lasting, improved corrosion control. The results of preliminary tests of the coatings and their resistance to salt spray corrosion are very encouraging, and commercial partners are sought for further development.

Leahy, Jonathan J.

2014-01-01

323

Powder metal matrix composites: selection and processing  

Microsoft Academic Search

There has been growing interest in the last decade in the development of metal matrix composites (MMCs) for the aerospace industry because of their attractive physical and mechanical properties and enhanced elevated temperature capabilities. However, some of the fabrication techniques (e.g. using powder metallurgy) for this new class of MMCs are hampered by (i) the poor distribution of the reinforcements,

M. J Tan; X Zhang

1998-01-01

324

Macromolecular powder diffraction : structure solution via molecular.  

SciTech Connect

Macromolecular powder diffraction is a burgeoning technique for protein structure solution - ideally suited for cases where no suitable single crystals are available. Over the past seven years, pioneering work by Von Dreele et al. [1,2] and Margiolaki et al. [3,4] has demonstrated the viability of this approach for several protein structures. Among these initial powder studies, molecular replacement solutions of insulin and turkey lysozyme into alternate space groups were accomplished. Pressing the technique further, Margiolaki et al. [5] executed the first molecular replacement of an unknown protein structure: the SH3 domain of ponsin, using data from a multianalyzer diffractometer. To demonstrate that cross-species molecular replacement using image plate data is also possible, we present the solution of hen egg white lysozyme using the 60% identical human lysozyme (PDB code: 1LZ1) as the search model. Due to the high incidence of overlaps in powder patterns, especially in more complex structures, we have used extracted intensities from five data sets taken at different salt concentrations in a multi-pattern Pawley refinement. The use of image plates severely increases the overlap problem due to lower detector resolution, but radiation damage effects are minimized with shorter exposure times and the fact that the entire pattern is obtained in a single exposure. This image plate solution establishes the robustness of powder molecular replacement resulting from different data collection techniques.

Doebbler, J.; Von Dreele, R.; X-Ray Science Division

2009-01-01

325

Frontal dynamics of powder snow avalanches  

NASA Astrophysics Data System (ADS)

We analyze frontal dynamics of dilute powder snow avalanches sustained by rapid blow-out behind the front. Such material injection arises as a weakly cohesive snow cover is fluidized by the very pore pressure gradient that the particle cloud induces within the snowpack. We model cloud fluid mechanics as a potential flow consisting of a traveling source of denser fluid thrust into a uniform airflow. Stability analysis of a mass balance involving snow cover and powder cloud yields relations among scouring depth, frontal height, speed, mixed-mean density, and impact pressure when the frontal region achieves a stable growth rate. We compare predictions with field measurements, show that powder clouds cannot reach steady frontal speed on a uniform snowpack with constant cloud width and derive a criterion for cloud ignition. Because static pressure is continuous across the mean air-cloud interface and deviatoric stresses are negligible, frontal acceleration is insensitive to local slope, but instead arises from a deficit of flow-induced suction in the wake. We calculate how far a powder cloud travels until its frontal mixed-mean density becomes stable, and show how topographic spread can hasten its collapse.

Carroll, C. S.; Louge, M. Y.; Turnbull, B.

2013-06-01

326

USING POWDERED ACTIVATED CARBON: A CRITICAL REVIEW  

EPA Science Inventory

Because the performance of powdered activated carbon (PAC) for uses other than taste and odor control is poorly documented, the purpose of this article is to critically review uses that have been reported (i.e., pesticides and herbicides, synthetic organic chemicals, and trihalom...

327

Ripples in Tapped or Blown Powder  

Microsoft Academic Search

We observe ripples forming on the surface of a granular powder in a container submitted from below to a series of brief and distinct shocks. After a few taps, the pattern turns out to be stable against any further shock of the same amplitude. We find that the wavelength of the pattern is proportional to the amplitude of the shocks.

Jacques Duran; M. Curie

2000-01-01

328

Low density fragile states in cohesive powders  

NASA Astrophysics Data System (ADS)

We discuss the difference between cohesive and non-cohesive granular media in the context of dry quicksand, recently proposed as a new fragile state of sand. We demonstrate that weak low density configurations with properties like dry quicksand are readily formed in many common household powders. In contrast, such states cannot be formed in non-cohesive granular media such as ordinary sand.

Umbanhowar, Paul B.; Goldman, Daniel I.

2006-08-01

329

Low density fragile states in cohesive powders  

E-print Network

We discuss the difference between cohesive and non-cohesive granular media in the context of a recent report of "dry quicksand." Weak low density states with properties like dry quicksand are readily formed in common household powders. In contrast, such states cannot be formed in cohesionless granular media such as ordinary sand.

Paul B. Umbanhowar; Daniel I. Goldman

2005-12-24

330

Black Hole Hair Removal  

E-print Network

Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair, -- degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

Banerjee, Nabamita; Sen, Ashoke

2009-01-01

331

Black Hole Hair Removal  

E-print Network

Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair, -- degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

Nabamita Banerjee; Ipsita Mandal; Ashoke Sen

2009-01-05

332

Exotic Black Holes  

E-print Network

Black hole solutions can be used to shed light on general issues in General Relativity and Quantum Physics. Black--hole hair, entropy and naked singularities are considered here, along with some implications for the inflationary universe scenario.

Ian G. Moss

1994-04-08

333

Black holes and radiometry  

E-print Network

Following Grischuk and Sidorov [Phys. Rev. D 42 (1990) 3413] in putting the Bogolubov-Hawking coefficient of Schwarzschild black-holes in the squeezing perspective, we provide a short discussion of Schwarzschild black holes as radiometric standards

H. C. Rosu

1997-10-27

334

tert-butyl-substituted cyclooctatetraenes  

SciTech Connect

Reaction of cyclooctatetraene (COT) with tert-butyllithium provides a convenient synthesis of tert-butylcyclooctatetraene, 4. As a byproduct of the reaction mixture, 1,4-di-tert-butylcyclooctatriene has been isolated and converted to 1,4-di-tert-butylcyclooctatetraene, 5, by deprotonation with potassium amide and oxidation with iodine. An independent synthesis of 5 was developed from 9-oxabicyclo(6.1.0)octa-2,4,6-triene (cyclooctatetraene oxide), 9. The highly substituted compound 1,3,5,7-tetra-tert-butylcyclooctatetraene (6) has been prepared in 24% overall yield in four steps. The acetylenic ketone 27, prepared from (tert-butylethynyl)copper and pivaloyl chloride, undergoes condensation with dimethyl malonate to give the pyrone ester 28. This ester undergoes facile hydrolysis and decarboxylation in hot concentrated sulfuric acid to yield 4,6-di-tert-butyl-2H-pyran-2-one (22) which is converted to 6 in one step by photolysis in dilute solution.

Miller, M.J. (Univ. of California, Berkeley); Lyttle, M.H.; Streitwieser, A. Jr.

1981-05-08

335

Uproar over Milk Substitutes Act.  

PubMed

Health policy activists lobbied 7 years for the Infant Milk Substitutes, Feeding Bottles and Infant Food Bill. Proponents of the bill say that it basically curtails unethical marketing practices, not the sales of baby foods, and argue that it was conceived to reduce the trend of mothers over-diluting commercial milk in order to reduce household expenses as well as stem the potential erosion of knowledge on locally available weaning foods. Even though the bill will become an Act only after its rules and regulations have been finalized, the government has already banned baby food advertisements on television and in other electronic media under its control. Women's groups now argue that the bill tends to focus almost exclusively upon the welfare of children and compromises the position of women who can not lactate adequately. Moreover, they hold that the bill may be used to compel wives to stay out of the formal workforce so that they may feed their babies. The intention of the bill may be meaningless without complementary legislation addressing the problems of working mothers. Specifically, amendments to the Maternity Benefits Act of 1961 would extend maternity leave to 4 months after delivery and lengthen the duration of nursing breaks. It is, however, feared that these changes may reduce employment prospects for women. PMID:12179211

1993-11-15

336

Life inside black holes  

E-print Network

We consider test planet and photon orbits of the third kind inside a black hole, which are stable, periodic and neither come out of the black hole nor terminate at the singularity. Interiors of supermassive black holes may be inhabited by advanced civilizations living on planets with the third-kind orbits. In principle, one can get information from the interiors of black holes by observing their white hole counterparts.

V. I. Dokuchaev

2012-03-05

337

Black Hole Berry Phase  

SciTech Connect

Supersymmetric black holes are characterized by a large number of degenerate ground states. We argue that these black holes, like other quantum mechanical systems with such a degeneracy, are subject to a phenomenon which is called the geometric or Berry's phase: under adiabatic variations of the background values of the supergravity moduli, the quantum microstates of the black hole mix among themselves. We present a simple example where this mixing is exactly computable, that of small supersymmetric black holes in 5 dimensions.

Boer, Jan de; Papadodimas, Kyriakos; Verlinde, Erik [Institute for Theoretical Physics, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)

2009-09-25

338

40 CFR 721.2532 - Substituted diphenylmethane (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted diphenylmethane (generic). 721.2532 Section...Substances § 721.2532 Substituted diphenylmethane (generic). (a) Chemical substance...identified generically as a substituted diphenylmethane (PMN P-97-4) is subject...

2010-07-01

339

40 CFR 721.8140 - Substituted propane (generic).  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Substituted propane (generic). 721.8140 Section 721...Substances § 721.8140 Substituted propane (generic). (a) Chemical substance...identified generically as a substituted propane (PMN P-01-298) is subject to...

2010-07-01

340

40 CFR 721.8140 - Substituted propane (generic).  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Substituted propane (generic). 721.8140 Section 721...Substances § 721.8140 Substituted propane (generic). (a) Chemical substance...identified generically as a substituted propane (PMN P-01-298) is subject to...

2013-07-01

341

40 CFR 721.8140 - Substituted propane (generic).  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Substituted propane (generic). 721.8140 Section 721...Substances § 721.8140 Substituted propane (generic). (a) Chemical substance...identified generically as a substituted propane (PMN P-01-298) is subject to...

2011-07-01

342

40 CFR 721.8140 - Substituted propane (generic).  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Substituted propane (generic). 721.8140 Section 721...Substances § 721.8140 Substituted propane (generic). (a) Chemical substance...identified generically as a substituted propane (PMN P-01-298) is subject to...

2012-07-01

343

40 CFR 721.640 - Amine substituted metal salts.  

Code of Federal Regulations, 2013 CFR

...false Amine substituted metal salts. 721.640 Section 721...640 Amine substituted metal salts. (a) Chemical substance...generically as amine substituted metal salts (PMNs P-96-1337/1338...uses are: (i) Release to water. Requirements as...

2013-07-01

344

40 CFR 721.562 - Substituted alkylamine salt.  

Code of Federal Regulations, 2011 CFR

...false Substituted alkylamine salt. 721.562 Section 721...562 Substituted alkylamine salt. (a) Chemical substance...as a substituted alkylamine salt (PMN P-85-941) is subject...uses are: (i) Release to water. Requirements as...

2011-07-01

345

40 CFR 721.640 - Amine substituted metal salts.  

Code of Federal Regulations, 2012 CFR

...false Amine substituted metal salts. 721.640 Section 721...640 Amine substituted metal salts. (a) Chemical substance...generically as amine substituted metal salts (PMNs P-96-1337/1338...uses are: (i) Release to water. Requirements as...

2012-07-01

346

40 CFR 721.640 - Amine substituted metal salts.  

Code of Federal Regulations, 2010 CFR

...false Amine substituted metal salts. 721.640 Section 721...640 Amine substituted metal salts. (a) Chemical substance...generically as amine substituted metal salts (PMNs P-96-1337/1338...uses are: (i) Release to water. Requirements as...

2010-07-01

347

40 CFR 721.640 - Amine substituted metal salts.  

Code of Federal Regulations, 2011 CFR

...false Amine substituted metal salts. 721.640 Section 721...640 Amine substituted metal salts. (a) Chemical substance...generically as amine substituted metal salts (PMNs P-96-1337/1338...uses are: (i) Release to water. Requirements as...

2011-07-01

348

40 CFR 721.6060 - Alkylaryl substituted phosphite.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Alkylaryl substituted phosphite. 721.6060 Section 721.6060... § 721.6060 Alkylaryl substituted phosphite. (a) Chemical substance and significant...identified generically as alkylaryl substituted phosphite (PMN P-91-899) is subject...

2010-07-01

349

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2010 CFR

... Substituted phenylimino carbamate derivative. 721.2025 Section 721.2025... Substituted phenylimino carbamate derivative. (a) Chemical substance and significant...as a substituted phenylimino carbamate derivative (PMN P-91-487) is subject...

2010-07-01

350

40 CFR 721.1760 - Substituted benzotriazole derivatives.  

Code of Federal Regulations, 2013 CFR

... false Substituted benzotriazole derivatives. 721.1760 Section 721.1760...721.1760 Substituted benzotriazole derivatives. (a) Chemical substances and significant...generically as substituted benzotriazole derivatives (PMNs P-93-374 and...

2013-07-01

351

40 CFR 721.1760 - Substituted benzotriazole derivatives.  

Code of Federal Regulations, 2012 CFR

... false Substituted benzotriazole derivatives. 721.1760 Section 721.1760...721.1760 Substituted benzotriazole derivatives. (a) Chemical substances and significant...generically as substituted benzotriazole derivatives (PMNs P-93-374 and...

2012-07-01

352

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2011 CFR

... Substituted phenylimino carbamate derivative. 721.2025 Section 721.2025... Substituted phenylimino carbamate derivative. (a) Chemical substance and significant...as a substituted phenylimino carbamate derivative (PMN P-91-487) is subject...

2011-07-01

353

40 CFR 721.1760 - Substituted benzotriazole derivatives.  

Code of Federal Regulations, 2010 CFR

... false Substituted benzotriazole derivatives. 721.1760 Section 721.1760...721.1760 Substituted benzotriazole derivatives. (a) Chemical substances and significant...generically as substituted benzotriazole derivatives (PMNs P-93-374 and...

2010-07-01

354

40 CFR 721.1760 - Substituted benzotriazole derivatives.  

Code of Federal Regulations, 2011 CFR

... false Substituted benzotriazole derivatives. 721.1760 Section 721.1760...721.1760 Substituted benzotriazole derivatives. (a) Chemical substances and significant...generically as substituted benzotriazole derivatives (PMNs P-93-374 and...

2011-07-01

355

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2012 CFR

... Substituted phenylimino carbamate derivative. 721.2025 Section 721.2025... Substituted phenylimino carbamate derivative. (a) Chemical substance and significant...as a substituted phenylimino carbamate derivative (PMN P-91-487) is subject...

2012-07-01

356

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2013 CFR

... Substituted phenylimino carbamate derivative. 721.2025 Section 721.2025... Substituted phenylimino carbamate derivative. (a) Chemical substance and significant...as a substituted phenylimino carbamate derivative (PMN P-91-487) is subject...

2013-07-01

357

Black holes in the universe  

Microsoft Academic Search

A general discussion of black holes in the universe is presented, including their predicted discovery, celestial mechanics, and theories regarding their interiors. Different types of black holes are discussed such as rotating and nonrotating black holes, mini black holes, supermassive black holes, and white holes. Suggestions are made with regard to determining the amount of black holes in the universe

I. D. Novikov

1977-01-01

358

40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).  

Code of Federal Regulations, 2010 CFR

...Polyethyleneamine crosslinked with substituted polyethylene glycol (generic). 721.7255...Polyethyleneamine crosslinked with substituted polyethylene glycol (generic). (a) Chemical...polyethyleneamine crosslinked with substituted polyethylene glycol with substituted...

2010-07-01

359

40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).  

Code of Federal Regulations, 2011 CFR

...Polyethyleneamine crosslinked with substituted polyethylene glycol (generic). 721.7255...Polyethyleneamine crosslinked with substituted polyethylene glycol (generic). (a) Chemical...polyethyleneamine crosslinked with substituted polyethylene glycol with substituted...

2011-07-01

360

The effect of polymorphism on powder compaction and dissolution properties of chemically equivalent oxytetracycline hydrochloride powders.  

PubMed

In South Africa, oxytetracycline is identified as an essential drug; many generic products are on the market, and many more are being developed. In this study, six oxytetracycline hydrochloride powders were obtained randomly from manufacturers, and suppliers were compared. It was found that compliance to a pharmacopoeial monograph was insufficient to ensure the optimum dissolution performance of a simple tablet formulation. Comparative physicochemical raw material analysis showed no major differences with regard to differential scanning calorimetry (DSC), infrared (IR) spectroscopy, powder dissolution, and particle size. However, the samples could be divided into two distinct types with respect to X-ray powder diffraction (XRD) and thus polymorphism. The two polymorphic forms had different dissolution properties in water or 0.1 N hydrochloride acid. This difference became substantial when the dissolution from tablets was compared. The powders containing form A were less soluble than that containing form B. PMID:10518242

Liebenberg, W; de Villiers, M M; Wurster, D E; Swanepoel, E; Dekker, T G; Lötter, A P

1999-09-01

361

Determinants of generic drug substitution in Switzerland  

PubMed Central

Background Since generic drugs have the same therapeutic effect as the original formulation but at generally lower costs, their use should be more heavily promoted. However, a considerable number of barriers to their wider use have been observed in many countries. The present study examines the influence of patients, physicians and certain characteristics of the generics' market on generic substitution in Switzerland. Methods We used reimbursement claims' data submitted to a large health insurer by insured individuals living in one of Switzerland's three linguistic regions during 2003. All dispensed drugs studied here were substitutable. The outcome (use of a generic or not) was modelled by logistic regression, adjusted for patients' characteristics (gender, age, treatment complexity, substitution groups) and with several variables describing reimbursement incentives (deductible, co-payments) and the generics' market (prices, packaging, co-branded original, number of available generics, etc.). Results The overall generics' substitution rate for 173,212 dispensed prescriptions was 31%, though this varied considerably across cantons. Poor health status (older patients, complex treatments) was associated with lower generic use. Higher rates were associated with higher out-of-pocket costs, greater price differences between the original and the generic, and with the number of generics on the market, while reformulation and repackaging were associated with lower rates. The substitution rate was 13% lower among hospital physicians. The adoption of the prescribing practices of the canton with the highest substitution rate would increase substitution in other cantons to as much as 26%. Conclusions Patient health status explained a part of the reluctance to substitute an original formulation by a generic. Economic incentives were efficient, but with a moderate global effect. The huge interregional differences indicated that prescribing behaviours and beliefs are probably the main determinant of generic substitution. PMID:21269426

2011-01-01

362

To Liberate Black Actors.  

ERIC Educational Resources Information Center

Three things will help to change American theater's unsatisfactory climate for Blacks and its growing mediocrity: (1) an end to the cultural dependence on British theater; (2) an examination of America's racial history in "White" as well as "Black" productions; and (3) abandonment of the notion that Blacks and Whites can flourish in isolation from…

Riley, Clayton

1983-01-01

363

Furnace Black Characterization  

E-print Network

of Crystallographic Studies #12;005F7 Methodologies #12;005F8 Summary · For all furnace carbon black 12� Surface Unorganized Carbon Identified #12;005F11 SRCC's Model #12;005F12 Carbon Black Surface Activity Energetic Surface Structure of Carbon Black (Summary) A. Schroeder | R. Schuster DIK #12;005F14 Polymer

364

The Nearest Black Hole  

NASA Technical Reports Server (NTRS)

The goal of this program is to study black holes, both in our Galaxy and in nearby galaxies. We aim to study both 'stellar mass' x-ray binaries containing black holes (both in our Galaxy and in nearby galaxies), and super-massive black holes in nearby galaxies.

Oliversen, Ronald (Technical Monitor); Garcia, Michael

2005-01-01

365

Black Women in Sport.  

ERIC Educational Resources Information Center

An overview of the achievements of black women in sports is presented in this collection of essays, biographical sketches, and philosophical investigations. The work is divided into five chapters, the first of which focuses on prejudice (racial and sexual), absence of black women as subjects in the research base, work/home/family pressures, black

Green, Tina Sloan; And Others

366

The Nearest Black Holes  

NASA Technical Reports Server (NTRS)

The goal of this program is to study black holes, both in our Galaxy and in nearby galaxies. We aim to study both "stellar mass" x-ray binaries containing black holes (both in our Galaxy and in nearby galaxies), and super-massive black holes in nearby galaxies.

Garcia, Michael R.; Oliversen, Ronald J. (Technical Monitor)

2002-01-01

367

The Black Woman.  

ERIC Educational Resources Information Center

The Black woman has been the transmitter of culture in the black community. Two of the important roles of African women were perpetuated during slavery and continue until today. They are her role in economic endeavor and her close bond with her children. The woman in African society was additionally politically significant. The black woman has…

Browne, Juanita M.

368

In vitro bioactivity of a biocomposite fabricated from HA and Ti powders by powder metallurgy method  

Microsoft Academic Search

Traditionally, hydroxyapatite was used as a coating material on titanium substrate by various techniques. In the present work, a biocomposite was successfully fabricated from hydroxyapatite and titanium powders by powder metallurgy method. Bioactivity of the composite in a simulated body fluid (SBF) was investigated. Main crystal phases of the as-fabricated composite are found to be Ti2O, CaTiO3, CaO, ?-Ti and

C. Q. Ning; Y. Zhou

2002-01-01

369

21 CFR 520.88d - Amoxicillin trihydrate soluble powder.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Amoxicillin trihydrate soluble powder. 520...ANIMAL DRUGS § 520.88d Amoxicillin trihydrate soluble powder. (a...Specifications. Each gram contains amoxicillin trihydrate equivalent to 115.4...

2010-04-01

370

Photocatalysis of phenol and salicyclic acid by nanostructured titania powders  

SciTech Connect

The photocatalytic destruction of phenol and salicylic acid was studied in aqueous suspensions of titania powders made in flame reactors. These powders were made in six hydrocarbon diffusion flames by hydrolysis and oxidation of TiCl{sub 4} that resulted in powders of high specific surface area and high anatase content. The photoactivity of the flame-made titania powders was compared with that of commercially available powders. Doping the titania with SiO{sub 2} was detrimental to the photoactivity of the powders in aerated solutions in contrast to non-aerated solutions. Titania powders in the range of 20-40 nm containing small amounts of rutile were more active than pure anatase powders. The phenol degradation reaction followed a first-order law while the Langmuir-Hinshelwood model was found to most accurately represent the photodegradation of salicylic acid.

Fotou, G.P.; Pratsinis, S.E. [Univ. of Cincinnati, OH (United States)

1995-12-31

371

Consolidation of aluminum 6061 powder by equal channel angular extrusion  

E-print Network

Equal channel angular extrusion is a promising approach to obtaining full density in powder metallurgy applications. This method can impose large effective deformations through uniform shear strain. Aluminum alloy 6061 powder is used as a test...

Pearson, John Montgomery

2012-06-07

372

A users' guide to understanding therapeutic substitutions.  

PubMed

Therapeutic substitutions are common at the level of ministries of health, clinicians, and pharmacy dispensaries. Guidance in determining whether drugs offer similar risk-benefit profiles is limited. Those making decisions on therapeutic substitutions should be aware of potential biases that make differentiating therapeutic agents difficult. Readers should consider whether the biological mechanisms and doses are similar across agents, whether the evidence is sufficiently valid across agents, and whether the safety and therapeutic effects of each drug are similar. This article uses a problem-based format to address the biological mechanism, validity, and results of a scenario in which therapeutic substitutions may be considered. PMID:24291506

Mills, Edward J; Gardner, David; Thorlund, Kristian; Briel, Matthias; Bryan, Stirling; Hutton, Brian; Guyatt, Gordon H

2014-03-01

373

Mössbauer Study of Multiple Substitutions in YBCO  

NASA Astrophysics Data System (ADS)

Mössbauer studies of multiple substitutions in YBCO with general formula (Y1-Z Ca Z )Ba2(Cu1-X-Y Fe Y M X )3O7-? are reported. XRD has been used to find out the lattice parameters. All the samples show a single tetragonal phase formation. Iodometric titration is done to estimate the oxygen content. The present study discusses the effect of multiple substitutions of 3d-ions like Ni, Zn, Co, Mn, Cr in YBCO and the effect of various substitutions on charge balancing, oxygen content and site occupancy.

Sarkar, M.; Patel, N. V.; Mehta, P. K.; Somayajulu, D. R. S.

2001-11-01

374

Study of Velocity and Materials on Tribocharging of Polymer Powders for Powder Coating Applications  

NASA Technical Reports Server (NTRS)

Electrostatic powder deposition is widely used in a plethora of industrial-applications ranging from the pharmaceutical and food.industries, to farm equipment and automotive applications. The disadvantages of this technique are possible back corona (pin-like formations) onset and the Faraday penetration limitation (when the powder does not penetrate in some recessed areas). A possible solution to overcome these problems is to use tribochargers to electrostatically charge the powder. Tribocharging, or contact charging while two materials are in contact, is related to the work function difference between the contacting materials and generates bipolarly charged particles. The generation of an ion-free powder cloud by tribocharging with high bipolar charge and an overall charge density of almost zero, provides a better coverage of the recessed areas. In this study, acrylic and epoxy powders were fluidized and charged by passing through stainless steel, copper, aluminum, and polycarbonate static mixers, respectively. The particle velocity was varied to determine its effect on the net charge-to-mass ratio (QIM) acquired by the powders. In general, the Q/M increases rapidly when the velocity was increased from 1.5 to 2.5 m/s, remaining almost constant for higher velocities. Charge separation experiments showed bipolar charging for all chargers.

Biris, Alex S.; Trigwell, Steve; Sims, Robert A.; Mazumder, Malay K.

2005-01-01

375

Hydroxylation of p-substituted phenols by tyrosinase: Further insight into the mechanism of tyrosinase activity  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer The action the copper complexes and tyrosinase on phenols is equivalent. Black-Right-Pointing-Pointer Isotope effect showed that nucleophilic attack to copper atom may be the slower step. Black-Right-Pointing-Pointer The value of {rho} (Hammett constant) supports an electrophilic aromatic substitution. Black-Right-Pointing-Pointer Data obtained in steady state pH 7 conditions support the mechanism of Scheme 1SM. -- Abstract: A study of the monophenolase activity of tyrosinase by measuring the steady state rate with a group of p-substituted monophenols provides the following kinetic information: k{sub cat}{sup m} and the Michaelis constant, K{sub M}{sup m}. Analysis of these data taking into account chemical shifts of the carbon atom supporting the hydroxyl group ({delta}) and {sigma}{sub p}{sup +}, enables a mechanism to be proposed for the transformation of monophenols into o-diphenols, in which the first step is a nucleophilic attack on the copper atom on the form E{sub ox} (attack of the oxygen of the hydroxyl group of C-1 on the copper atom) followed by an electrophilic attack (attack of the hydroperoxide group on the ortho position with respect to the hydroxyl group of the benzene ring, electrophilic aromatic substitution with a reaction constant {rho} of -1.75). These steps show the same dependency on the electronic effect of the substituent groups in C-4. Furthermore, a study of a solvent deuterium isotope effect on the oxidation of monophenols by tyrosinase points to an appreciable isotopic effect. In a proton inventory study with a series of p-substituted phenols, the representation of k{sub cat}{sup f{sub n}}/k{sub cat}{sup f{sub 0}} against n (atom fractions of deuterium), where k{sub cat}{sup f{sub n}} is the catalytic constant for a molar fraction of deuterium (n) and k{sub cat}{sup f{sub 0}} is the corresponding kinetic parameter in a water solution, was linear for all substrates. These results indicate that only one of the proton transfer processes from the hydroxyl groups involved the catalytic cycle is responsible for the isotope effects. We suggest that this step is the proton transfer from the hydroxyl group of C-1 to the peroxide of the oxytyrosinase form (E{sub ox}). After the nucleophilic attack, the incorporation of the oxygen in the benzene ring occurs by means of an electrophilic aromatic substitution mechanism in which there is no isotopic effect.

Munoz-Munoz, Jose Luis [GENZ - Grupo de Investigacion Enzimologia, Departamento de Bioquimica y Biologia Molecular-A, Facultad de Biologia, Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain)] [GENZ - Grupo de Investigacion Enzimologia, Departamento de Bioquimica y Biologia Molecular-A, Facultad de Biologia, Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Berna, Jose [Grupo de Quimica Organica Sintetica, Departamento de Quimica Organica, Facultad de Quimica Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia (Spain)] [Grupo de Quimica Organica Sintetica, Departamento de Quimica Organica, Facultad de Quimica Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia (Spain); Garcia-Molina, Maria del Mar; Garcia-Molina, Francisco [GENZ - Grupo de Investigacion Enzimologia, Departamento de Bioquimica y Biologia Molecular-A, Facultad de Biologia, Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain)] [GENZ - Grupo de Investigacion Enzimologia, Departamento de Bioquimica y Biologia Molecular-A, Facultad de Biologia, Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Garcia-Ruiz, Pedro Antonio [QCPAI - Grupo de Quimica de Carbohidratos, Polimeros y Aditivos Industriales, Departamento de Quimica Organica, Facultad de Quimica Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia (Spain)] [QCPAI - Grupo de Quimica de Carbohidratos, Polimeros y Aditivos Industriales, Departamento de Quimica Organica, Facultad de Quimica Campus Internacional de Excelencia Campus Mare Nostrum, Universidad de Murcia (Spain); Varon, Ramon [Departamento de Quimica-Fisica, Escuela de Ingenieros Industriales de Albacete, Universidad de Castilla la Mancha, Avda. Espana s/n. Campus Universitario, E-02071 Albacete (Spain)] [Departamento de Quimica-Fisica, Escuela de Ingenieros Industriales de Albacete, Universidad de Castilla la Mancha, Avda. Espana s/n. Campus Universitario, E-02071 Albacete (Spain); and others

2012-07-27

376

Electrical Conductivity of Metal Powders under Shock Compression  

Microsoft Academic Search

The electrical conductivity of a series of metal powders under shock compression is measured by an electrocontact technique. Initially, the metal particles are covered by an oxide film, and the powder is non-conducting. Under shock compression, the powder acquires macroscopic conductivity. The electrical conductivity of the shock-compressed powder depends substantially on the metal, porosity, particle size, and shock-wave pressure. The

S. D. Gilev

2005-01-01

377

Powder segregation during the filling of a simple die  

E-print Network

POWDER SEGREGATION DURING THE FILLING OF A SIMPLE DIE A study of powder segregation during die filling with two component mixes of lead particles has shown that: I. Segregation occurs by fines filtering down through the moving powder mass. This effect... and density in the mixtures studied have little effect upon segrege. tion, 4. Increasing the rate of die filling decreases opportu- nity for segregation. 5. Increasing the height from which the powder falls into the die causes mixing and decreases...

Lawrence, Larry Raymond

2012-06-07

378

Crystallization of Amorphous Components in Spray-Dried Powders  

Microsoft Academic Search

Spray-dried powders are typically produced as amorphous particles. Long storage of the particles tends to crystallize the powders, a reaction affected by moisture, time, and temperature. This work has examined partial crystallization from amorphous spray-dried powders by moisture sorption. Powders of citrus fiber with hibiscus extract, maltodextrin, coffee, tea, skim milk, and sucrose were produced with a laboratory-scale spray dryer.

D. Chiou; T. A. G. Langrish

2007-01-01

379

40 CFR 721.267 - N-[2-[(substituted dinitrophenyl)azo]diallylamino-4- substituted phenyl] acetamide (generic name).  

Code of Federal Regulations, 2010 CFR

...azo]diallylamino-4- substituted phenyl] acetamide (generic name). 721...azo]diallylamino-4- substituted phenyl] acetamide (generic name). (a...azo]diallylamino-4-substituted phenyl] acetamide (PMN P-95-513)...

2010-07-01

380

Two tetra-Cd(II)-substituted vanadogermanate frameworks.  

PubMed

Two new tetra-Cd(II)-substituted vanadogermanate frameworks {(CdX)4Ge8V(IV)10O46(H2O)[V(III)(H2O)2]4(GeO2)4}·8H2O (X = ethylenediamine (en, 1) and 1,2-diaminopropane (dap, 2)) were hydrothermally prepared and characterized by IR spectra, elemental analysis, powder X-ray diffraction (PXRD), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and X-ray single-crystal diffraction. Both are isomorphic, and their 3-D frameworks are made up of tetra-Cd(II)-substituted {(CdX)4Ge8V(IV)10O46(H2O)}(12-) fundamental building units interconnected through planar tetra-V(III) [V(III)4O2(H2O)8](8-) clusters and tetrahedral GeO4 bridges. In the unique {(CdX)4Ge8V(IV)10O46(H2O)}(12-) cage, four [Ge2O7] dimers and four CdO4N2 trigonal prisms are alternately concatenated by ?3-O bridges to create a round {Ge8Cd4O28(X)4}(16-) fragment, five VO5 groups are linked by sharing edges to generate a pentanuclear [V5O17] subunit, and then the {Ge8Cd4O28(X)4}(16-) fragment is sandwiched by two V5O17 subunits via sharing O-atoms producing a D4h-symmetric {(CdX)4Ge8V(IV)10O46(H2O)}(12-) cage with a free water molecule located at the center. As we know, both display unprecedented 3-D organic-inorganic hybrid frameworks built up from the largest number of transition-metal-substituted vanadogermanate {(CdX)4Ge8V(IV)10O46}(12-) cluster shells linked by both GeO4 tetrahedra and rare [V(III)4O2(H2O)8](8-) clusters. Magnetic measurements reveal the antiferromagnetic couplings within the magnetic vanadium centers. PMID:24641354

Zhou, Jian; Zhao, Jun-Wei; Wei, Qi; Zhang, Jie; Yang, Guo-Yu

2014-04-01

381

Do Black Holes Exist?  

E-print Network

We discuss and compare definitions of a black hole based on the existence of event and apparent horizons. In this connection we present a non-singular model of a black hole with a closed apparent horizon and discuss its properties. We propose a massive thin shell model for consistent description of particles creation in black holes. Using this model we demonstrate that for black holes with mass much larger than the Planckian one the backreaction of the domain, where the particles are created, on the black hole parameters is negligibly small.

Frolov, Valeri P

2014-01-01

382

Black holes without boundaries  

E-print Network

We discuss some of the drawbacks of using event horizons to define black holes and suggest ways in which black holes can be described without event horizons, using trapping horizons. We show that these trapping horizons give rise to thermodynamic behavior and possibly Hawking radiation too. This raises the issue of whether the event horizon or the trapping horizon should be seen as the true boundary of a black hole. This difference is important if we believe that quantum gravity will resolve the central singularity of the black hole and clarifies several of the issues associated with black hole thermodynamics and information loss.

Alex B. Nielsen

2008-09-10

383

Phantom Black Holes  

E-print Network

The exact solutions of electrically charged phantom black holes with the cosmological constant are constructed. They are labelled by the mass, the electrical charge, the cosmological constant and the coupling constant between the phantom and the Maxwell field. It is found that the phantom has important consequences on the properties of black holes. In particular, the extremal charged phantom black holes can never be achieved and so the third law of thermodynamics for black holes still holds. The cosmological aspects of the phantom black hole and phantom field are also briefly discussed.

C. J. Gao; S. N. Zhang

2006-04-17

384

Black Hole Chemistry  

E-print Network

The mass of a black hole has traditionally been identified with its energy. We describe a new perspective on black hole thermodynamics, one that identifies the mass of a black hole with chemical enthalpy, and the cosmological constant as thermodynamic pressure. This leads to an understanding of black holes from the viewpoint of chemistry, in terms of concepts such as Van der Waals fluids, reentrant phase transitions, and triple points. Both charged and rotating black holes exhibit novel chemical-type phase behaviour, hitherto unseen.

David Kubiznak; Robert B. Mann

2014-04-08

385

Black Hole Chemistry  

E-print Network

The mass of a black hole has traditionally been identified with its energy. We describe a new perspective on black hole thermodynamics, one that identifies the mass of a black hole with chemical enthalpy, and the cosmological constant as thermodynamic pressure. This leads to an understanding of black holes from the viewpoint of chemistry, in terms of concepts such as Van der Waals fluids, reentrant phase transitions, and triple points. Both charged and rotating black holes exhibit novel chemical-type phase behaviour, hitherto unseen.

Kubiznak, David

2014-01-01

386

Magnetized static black Saturn  

E-print Network

We construct a new static solution to the 5D Einstein-Maxwell equations describing a static black hole surrounded by a non-rotating dipole black ring. The configuration is kept in equilibrium by an external magnetic field interacting with the dipole charge of the black ring. The properties of the black Saturn-like configuration are studied and the basic physical quantities are calculated. The solution demonstrates 2-fold continuous non-uniqueness of the 5D magnetized static neutral black objects for fixed total mass and Melvin background.

Stoytcho S. Yazadjiev

2008-02-06

387

Black hole levitron  

SciTech Connect

We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.'s multicenter supersymmetric black hole solutions provides a supergravity description of such backgrounds within which a black hole can be trapped within a confined volume. This construction is realized by solving for a levitating black hole over a magnetic dipole base. We comment on how such a construction is akin to a mechanical levitron.

Arsiwalla, Xerxes D.; Verlinde, Erik P. [Institute for Theoretical Physics, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)

2010-04-15

388

Low temperature carburization of high surface area tungsten powders  

Microsoft Academic Search

Reductive decomposition of WO3 precursor powder gives high surface area ?-W at temperatures above 650 °C, ?-W at temperatures below 575 °C, and mixtures of ?-W and ?-W (in various ratios) at intermediate temperatures. The carburization behavior of these powders in flowing CO over the temperature range 350 °–700 °C is sensitive to the initial crystalline state of the powder.

L. Gao; B. H. Kear

1995-01-01

389

New Ferro Powder for Selective Laser Sintering of Dense Parts  

Microsoft Academic Search

The paper describes a new powder composition specially developed for selective laser sintering (SLS). The aim is to obtain a ferro powder that can be sintered without need for a (sacrificial) polymer binder and that results in quasi dense parts that do not need any post-processing like furnace sintering, infiltration or HIP. The powder is a mixture of different types

J. P. Kruth; L. Froyen; M. Rombouts; J. Van Vaerenbergh; P. Mercells

2003-01-01

390

IMPROVEMENT OF CONCRETE DURABILITY BY COMPLEX MINERAL SUPERFINE POWDER  

Microsoft Academic Search

The green concrete capable for sustainable development is characterized by application of industrial wastes to reduce consumption of natural resources and energy and pollution of the environment. KG powder is a complex mineral superfine powder made by grinding the mix of calcined coal gangue and slag in certain proportion. Through reaction with the concrete admixture, KG powder improved pozzolanic reaction,

Chen Han-bin; Chen Jian-xiong; Xiao Fei; Cui Hong-ta

391

Comparison of Water Vapor Sorption by Milk Powder Components  

Microsoft Academic Search

Water vapor is absorbed by milk powder at sites dependent upon the relative pres- sure, P\\/Po, of the atmosphere to which the powder is exposed. Comparison of the water sorption isotherms for the protein, sugar, and mixed salts comparable with that found in milk powder indicated that at low P\\/Po water is bound primarily by the casein fraction in the

B. A. Anderson; M. J. Pallansch

1968-01-01

392

Hydrothermal synthesis of zinc oxide powders with controllable morphology  

Microsoft Academic Search

Crystalline zinc oxide powders with various morphologies have been prepared by hydrothermal treatment of zinc acetate in pure water, KOH or ammonia aqueous solution. It was found that the selected solvents play a different role in controlling the morphologies of the obtained powders. The variation of morphology of the obtained ZnO powder with solvents mainly depends on the different zinc

HaiYan Xu; Hao Wang; YongCai Zhang; WenLiang He; ManKang Zhu; Bo Wang; Hui Yan

2004-01-01

393

Synthesis of titanium carbide nano-powders by thermal plasma  

Microsoft Academic Search

The paper presents a thermodynamic analysis for predicting the conditions for the plasma synthesis of TiC powders. The paper also investigates the effects of feeding rate and molar ratio. The experimental results show that TiC powders are synthesized by thermal plasma and the average size of the TiC powders is less than 100nm.

Lirong Tong; Ramana G. Reddy

2005-01-01

394

Barium strontium titanate powders prepared by spray pyrolysis  

Microsoft Academic Search

Ultasonic spray pyrolysis (SP) has been investigated for the production of the barium strontium titanate (BST) powders from the polymeric precursors. The processing parameters, such as flux of aerosol and temperature profile inside the furnace, were optimized to obtain single phase BST. The powders were characterized by the methods of X-ray diffraction analysis, SEM, EDS and TEM. The obtained powders

G. Brankovi?; Z. Brankovi?; M. S. Góes; C. O. Paiva-Santos; M. Cilense; J. A. Varela; E. Longo

2005-01-01

395

Fines Loadings in Milk Powder Plants with Washable Baghouses  

Microsoft Academic Search

Washable baghouses are increasingly used to filter the small size fractions of milk powder, known as fines, which become entrained with spray dryer outlet air streams in milk powder plants. Surprisingly, very little is known about the quantity of powder that becomes fines, an important parameter for both the control of agglomeration rates and washable bag-house design. A convenient method

J. R. Gabites; J. Abrahamson; J. A. Winchester

2007-01-01

396

Acid Strengths of Some Substituted Picric Acids.  

National Technical Information Service (NTIS)

The aqueous dissociation constants for a number of substituted picric acids and related compounds were determined spectrophotometrically, and the values obtained correlated with the mid-equivalence potentials obtained by half-neutralization in acetone sol...

P. J. Pearce, R. J. J. Simkins

1968-01-01

397

Questioning nuclear waste substitution: a case study.  

PubMed

This article looks at the ethical quandaries, and their social and political context, which emerge as a result of international nuclear waste substitution. In particular it addresses the dilemmas inherent within the proposed return of nuclear waste owned by Japanese nuclear companies and currently stored in the United Kingdom. The UK company responsible for this waste, British Nuclear Fuels Limited (BNFL), wish to substitute this high volume intermediate-level Japanese-owned radioactive waste for a much lower volume of much more highly radioactive waste. Special focus is given to ethical problems that they, and the UK government, have not wished to address as they move forward with waste substitution. The conclusion is that waste substitution can only be considered an ethical practice if a set of moderating conditions are observed by all parties. These conditions are listed and, as of yet, they are not being observed. PMID:17703611

Marshall, Alan

2007-03-01

398

Substituted Phenserines as Specific Inhibitors of Acetylcholinesterase.  

National Technical Information Service (NTIS)

The invention relates to substituted phenylcarbamate or naphthylcarbamate tricyclic compounds which provide highly potent and selective cholinergic agonist and blocking activity and their use as pharmaceutical agents. The invention further relates to impr...

A. Brossi, M. Brzostowska, S. I. Rapoport, N. Greig, X. S. He

1991-01-01

399

Direct analysis of herbal powders by pipette-tip electrospray ionization mass spectrometry.  

PubMed

Conventional electrospray ionization mass spectrometry (ESI-MS) is widely used for analysis of solution samples. The development of solid-substrate ESI-MS allows direct ionization analysis of bulky solid samples. In this study, we developed pipette-tip ESI-MS, a technique that combines pipette tips with syringe and syringe pump, for direct analysis of herbal powders, another common form of samples. We demonstrated that various herbal powder samples, including herbal medicines and food samples, could be readily online extracted and analyzed using this technique. Various powder samples, such as Rhizoma coptidis, lotus plumule, great burdock achene, black pepper, Panax ginseng, roasted coffee beans, Fructus Schisandrae Chinensis and Fructus Schisandrae Sphenantherae, were analyzed using pipette-tip ESI-MS and quality mass spectra with stable and durable signals could be obtained. Both positive and negative ion modes were attempted and various compounds including amino acids, oligosaccharides, glycosides, alkaloids, organic acids, ginosensides, flavonoids and lignans could be detected. Principal component analysis (PCA) based on the acquired mass spectra allowed rapid differentiation of closely related herbal species. PMID:24418140

Wang, Haixing; So, Pui-Kin; Yao, Zhong-Ping

2014-01-27

400

Nutrient-substituted hydroxyapatites: synthesis and characterization  

NASA Technical Reports Server (NTRS)

Incorporation of Mg, S, and plant-essential micronutrients into the structure of synthetic hydroxyapatite (HA) may be advantageous for closed-loop systems, such as will be required on Lunar and Martian outposts, because these apatites can be used as slow-release fertilizers. Our objective was to synthesize HA with Ca, P, Mg, S, Fe, Cu, Mn, Zn, Mo, B, and Cl incorporated into the structure, i.e., nutrient-substituted apatites. Hydroxyapatite, carbonate hydroxyapatite (CHA), nutrient-substituted hydroxyapatite (NHA), and nutrient-substituted carbonate hydroxyapatite (NCHA) were synthesized by precipitating from solution. Chemical and mineralogical analysis of precipitated samples indicated a considerable fraction of the added cations were incorporated into HA, without mineral impurities. Particle size of the HA was in the 1 to 40 nm range, and decreased with increased substitution of nutrient elements. The particle shape of HA was elongated in the c-direction in unsubstituted HA and NHA but more spherical in CHA and NCHA. The substitution of cations and anions in the HA structure was confirmed by the decrease of the d[002] spacing of HA with substitution of ions with an ionic radius less than that of Ca or P. The DTPA-extractable Cu ranged from 8 to 8429 mg kg-1, Zn ranged from 57 to 1279 mg kg-1, Fe from 211 to 2573 mg kg-1, and Mn from 190 to 1719 mg kg-1, depending on the substitution level of each element in HA. Nutrient-substituted HA has the potential to be used as a slow-release fertilizer to supply micronutrients, S, and Mg in addition to Ca and P.

Golden, D. C.; Ming, D. W.

1999-01-01

401

Chemical characterization of silicon-substituted hydroxyapatite.  

PubMed

Bioceramic specimens have been prepared by incorporating a small amount of silicon (0.4 wt %) into the structure of hydroxyapatite [Ca10(PO4)6(OH)2, HA] via an aqueous precipitation reaction to produce a silicon-substituted hydroxyapatite (Si-HA). The results of chemical analysis confirmed the proposed substitution of the silicon (or silicate) ion for the phosphorus (or phosphate) ion in hydroxyapatite. The Si-HA was produced by first preparing a silicon-substituted apatite (Si-Ap) by a precipitation process. A single-phase Si-HA was obtained by heating/calcining the as-prepared Si-Ap to temperatures above 700 degrees C; no secondary phases, such as tricalcium phosphate (TCP), tetracalcium phosphate (TeCP), or calcium oxide (CaO), were observed by X-ray diffraction analysis. Although the X-ray diffraction patterns of Si-HA and stoichiometric HA appeared to be identical, refinement of the diffraction data revealed some small structural differences between the two materials. The silicon substitution in the HA lattice resulted in a small decrease in the a axis and an increase in the c axis of the unit cell. This substitution also caused a decrease in the number of hydroxyl (OH) groups in the unit cell, which was expected from the proposed substitution mechanism. The incorporation of silicon in the HA lattice resulted in an increase in the distortion of the PO4 tetrahedra, indicated by an increase in the distortion index. Analysis of the Si-HA by Fourier transform infrared (FTIR) spectroscopy indicated that although the amount of silicon incorporated into the HA lattice was small, silicon substitution appeared to affect the FTIR spectra of HA, in particular the P-O vibrational bands. The results demonstrate that phase-pure silicon-substituted hydroxyapatite may be prepared using a simple precipitation technique. PMID:10397946

Gibson, I R; Best, S M; Bonfield, W

1999-03-15

402

"Black Star" or Astrophysical Black Hole?  

E-print Network

Recently wide publicity has been given to a claim by T. Vachaspati that "black holes do not exist", that the objects known as black holes in astrophysics should rather be called "black stars" and they not only do not have event horizons but actually can be the source of spectacular gamma ray bursts. In this short essay (no flimsier than the original preprint where these extravagant claims appeared) I demonstrate that these ill-considered claims are clearly wrong. Yet they present a good occasion to reflect on some well known but little discussed conceptual difficulties which arise when applying relativistic terminology in an astrophysical context.

K. Petrovay

2007-07-17

403

High-purity, fine-particle boron nitride powder synthesis at -75 to 750C. Report of investigations/1986  

SciTech Connect

Nonoxide ceramics with improved high-temperature properties could substitute for high-temperature alloys and reduce the Nation's dependence on imports of Cr, Co, Ni, and Mn. To meet the objective, the Bureau of Mines conducted research to synthesize ultrafine reactive boron nitride (BN) powders. BN powders were prepared at temperatures ranging from -75 degrees to 750 degrees C. Low-temperature reactions (-75 to 200/sup 0/C) between boron halides and N compounds led to formation of elemento-organic compounds that were thermally decomposed to ultrafine (approximately 100- to 150-A particle size) reactive BN powders. BN powders were also prepared through the reaction of a low-melting inorganic B compound (boric acid, borax) with an organic N compound (carbimide and thiocarbimide) in N/sub 2/ and/or ammonia (NH/sub 3/) atmospheres at temperatures between 500 and 750/sup 0/C. The report is based upon work done under an agreement between the University of Alabama and the Bureau of Mines.

Kalyoncu, R.S.

1986-01-01

404

Electrophoretic deposition of nanosized ceramic powders  

SciTech Connect

For nanosized powders the forming of compacts by electrophoretic deposition is an interesting method. In aqueous suspensions high deposition rates can be achieved at low electric fields. The problems with the gas bubble formation at the electrodes which are caused by the decomposition of water can be solved by depositing the compact on a microporous membrane in front of the electrode. Thus, with nanosized zirconia powders made by the flame hydrolysis (BET-surface area approx. 50 M{sup 2}/g) the deposition rate was measured as a function of deposition time and electrolyte concentration. Furthermore, the deposition rate depends on the effective electric field inside the suspension, which is much lower in zirconia suspensions than in comparable silica suspensions. In spite of this, deposition rates up to 0.5 g/min {center_dot} CM{sup 2} were achieved. The deposited compacts showed a small pore size distribution (max. 25 nm) and a relative green density of 40%.

Clasen, R.; Janes, S.; Oswald, C.; Ranker, D. [Institut fuer Neue Materialien gem GmbH, Saarbruechek (Germany)

1995-09-01

405

Dry powder mixes comprising phase change materials  

DOEpatents

Free flowing, conformable powder-like mix of silica particles and a phase change material (pcm) is disclosed. The silica particles have a critical size of about 7[times]10[sup [minus]3] to about 7[times]10[sup [minus]2] microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 10 figures.

Salyer, I.O.

1993-10-19

406

Dry powder mixes comprising phase change materials  

DOEpatents

Free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a PCM material. The silica-PCM mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 2 figures.

Salyer, I.O.

1994-02-01

407

Dry powder mixes comprising phase change materials  

DOEpatents

Free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a PCM material. The silica-PCM mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1994-01-01

408

Dry powder mixes comprising phase change materials  

DOEpatents

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garmets, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1993-01-01

409

Dry powder mixes comprising phase change materials  

DOEpatents

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1992-01-01

410

Dry powder mixes comprising phase change materials  

DOEpatents

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, Ival O. (Dayton, OH)

1993-01-01

411

Mixing of zeolite powders and molten salt  

SciTech Connect

Transuranics and fission products in a molten salt can be incorporated into zeolite A by an ion exchange process and by a batch mixing or blending process. The zeolite is then mixed with glass and consolidated into a monolithic waste form for geologic disposal. Both processes require mixing of zeolite powders with molten salt at elevated temperatures (>700 K). Complete occlusion of salt and a uniform distribution of chloride and fission products are desired for incorporation of the powders into the final waste form. The relative effectiveness of the blending process was studied over a series of temperature, time, and composition profiles. The major criteria for determining the effectiveness of the mixing operations were the level and uniformity of residual free salt in the mixtures. High operating temperatures (>775 K) improved salt occlusion. Reducing the chloride levels in the mixture to below 80% of the full salt capacity of the zeolite significantly reduced the free salt level in the final product.

Pereira, C.; Zyryanov, V.N.; Lewis, M.A.; Ackerman, J.P.

1996-05-01

412

Dry powder mixes comprising phase change materials  

DOEpatents

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7[times]10[sup [minus]3] to about 7[times]10[sup [minus]2] microns and the p.c.m. must be added to the silica in an amount of 80 wt. % or less p.c.m. per combined weight of silica and p.c.m. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a p.c.m. material. The silica-p.c.m. mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Salyer, I.O.

1993-05-18

413

Shock compaction of molybdenum nitride powder  

NASA Astrophysics Data System (ADS)

Molybdenum nitride has a potential application in multi layer capacitors. Since this material is not readily available in bulk form, molybdenum nitride powder, consisting of a mixture of the nitrides Mo2N and MoN has been compacted to 12 mm circular, 1-2 mm thick discs utilizing shock-compression technique. Powders were packed to 55-67 percent of the crystal density and shock compacted using a plate impact shock recovery system at 1.35 to 1.81 km/s impact velocity. The recovered compacts were characterized by scanning electron microscope, x-ray diffraction and cyclic voltammetry to evaluate its electrochemical stability in sulphuric acid. This paper presents the optimization technique used for compaction and the characteristics of the recovered compacts.

Roberson, S.; Davis, R. F.; Joshi, V. S.; Fienello, D.

1998-07-01

414

Influence of Ball-Milling Treatment of B Original Powder on the Phase Formation and Critical Current Density of Graphite Doped MgB  

NASA Astrophysics Data System (ADS)

In present work, the sintering process and superconducting properties of graphite doped MgB prepared with milled B original powder were investigated. It is found that ball milling treatment of B original powder obviously suppresses the solid-solid reaction between Mg and B, whereas it enhances their liquid-solid reaction during the subsequent sintering process of these graphite doped MgB bulks. Ball milling treatment of B original powder can also promote C substitution for B sites in MgB crystal lattice in the graphite-doped samples, and thus obviously increase their values of at high fields. Moreover, ball milling also refines MgB grains, enhancing grain boundary pinning and at high fields.

Su, Xiaocheng; Jiang, Qingguo; Zuo, Anying

2014-10-01

415

77 FR 28252 - Oral Dosage Form New Animal Drugs; Change of Sponsor; Griseofulvin Powder; Levamisole...  

Federal Register 2010, 2011, 2012, 2013

...Change of Sponsor; Griseofulvin Powder; Levamisole Hydrochloride Powder; Oxytetracycline...ANADAs) for griseofulvin powder, levamisole hydrochloride soluble powder, and oxytetracycline...and ANADAs 200-313 and 200-386 for Levamisole Hydrochloride Soluble Pig Wormer...

2012-05-14

416

Properties of HIPed stainless steel powder  

Microsoft Academic Search

In the current design of ITER primary wall, 316LN stainless steel is the reference structural material. Austenitic stainless steel is used for water-cooling channels and structures. As material data on hot isostatic pressed (HIP) 316LN were not available in open literature and from powder producers, the main properties of unirradiated samples have been measured in CEA\\/CEREM. Fully dense material without

Ch. Dellis; G. Le Marois; J. M. Gentzbittel; G. Robert; F. Moret

1996-01-01

417

Porous materials from electrolytic chromium powder  

Microsoft Academic Search

Three fractions of electrolytic chromium powder, 0.2, 0.3, and 0.4 ram, were chosen for investigation. The designations of these fractions are highly arbitrary, because, for example, a thin lamellar particle up to 1 mm long can pass through a seive with 0.4-ram apertures. Metallographie examination (Fig. 1) and visual inspection revealed that, while the particles of the 0.2-ram fraction in

S. M. Solonin; V. B. Akimenko

1971-01-01

418

Tunable visible photoluminescence of powdered silica glass  

Microsoft Academic Search

Intense photoluminescence in the visible region was observed at room temperature in standard soda-lime-silica glass powder, mechanically milled in a high-energy attrition mill. The emission band maximum shows an interesting dependence on the exciting wavelength, suggesting the possibility to tune the PL emission. These findings indicate that the photoluminescence may be directly related to unsatisfied chemical bonds correlated with the

P. S. Pizani; M. R. Joya; F. M. Pontes; L. P. S. Santos; M GODINHOJR; E. R. Leite; E. Longo

2008-01-01

419

Shock compression response of magnetic nanocomposite powders  

Microsoft Academic Search

The shock compression response of magnetic Pr2Fe14B\\/?-Fe nanocomposite powders, pressed at different packing densities, was studied in the range of 11–23 GPa shock pressure, using a single-stage gas gun. Bulk compacts (97.5–99% dense) recovered in the form of 12 mm diameter by 4 mm thick disks, were analyzed to determine the structural changes occurring within the particles and at particle

Z. Q. Jin; K. H. Chen; J. Lia; H. Zeng; S.-F. Cheng; J. P. Liu; Z. L. Wang; N. N. Thadhani

2004-01-01

420

Fabricating sports equipment components via powder metallurgy  

Microsoft Academic Search

Powder metallurgy (P\\/M) offers a viable, cost-effective approach to fabricating sports and leisure equipment components. Both\\u000a complex, monolithic parts and parts produced from materials of quite different densities can be manufactured by this technique.\\u000a In the latter category, lightweight titanium and heavyweight tungsten can be used in combination to optimally distribute mass,\\u000a such as in golf club heads. Examples of

V. S. Moxson

2001-01-01

421

Nanostructured cobalt powders synthesised by polyol process and consolidated by Spark Plasma Sintering: Microstructure and mechanical properties  

SciTech Connect

Bulk nanostructured cobalt was processed using a bottom-up strategy. Nanostructured particle agglomerates of about 50 and 240 nm in diameter were synthesised using a polyol route and subsequently consolidated by Spark Plasma Sintering (SPS). The microstructure of the starting powders and of the processed bulk samples was studied and characterised by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the as-prepared powders showed predominantly a face centred cubic (fcc) crystalline phase, whereas both fcc and hexagonal close packed (hcp) phases were found within the consolidated samples. A sample with the highest relative mass density (94.5%) was obtained from the small powder particles. TEM observations revealed a lamellar substructure with a high density of nanotwins and stacking faults in every grain in the sample with the highest density. Brillouin light scattering (BLS) and quasistatic compression tests were used to investigate the mechanical properties of the consolidated samples. The two techniques yielded Young modulus values of 168 GPa and 130 GPa, respectively, in the sample with the highest density. This sample also exhibited a yield stress higher than 1 GPa after the compression test, which is mainly attributed to the lamellar-like structure occurring in almost every grain of the polycrystalline aggregate. - Highlights: Black-Right-Pointing-Pointer Cobalt nanoparticles produced by the polyol process present mainly the fcc metastable phase. Black-Right-Pointing-Pointer Bulk nanostructured cobalt is obtained from the nano-particles by Spark Plasma Sintering consolidation. Black-Right-Pointing-Pointer Nanotwins and stacking faults are present in every grain of the more dense sample. Black-Right-Pointing-Pointer Yield strength and plastic domain may be varied depending on the nanoparticle size and the porosity of the consolidated material.

Fellah, F.; Schoenstein, F.; Dakhlaoui-Omrani, A.; Cherif, S.M.; Dirras, G.; Jouini, N., E-mail: jouini@univ-paris13.fr

2012-07-15

422

(Ln = Eu, Tb, and Dy) Powders  

NASA Astrophysics Data System (ADS)

BaWO4:Ln3+ powders were synthesized by a solid-state reaction method. The BaWO4:Ln3+ samples were characterized by x-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM), and luminescence spectroscopy. The XRD patterns reveal that the BaWO4:Ln3+ samples present pure tetragonal scheelite structure. The SEM observations demonstrate that the BaWO4:Ln3+ powders are irregular particles with size in the range of micrometers. The excitation spectra of the BaWO4:Ln3+ samples show the broad absorption band originating from charge transfer between oxygen ligands and the central tungstate ions inside WO{4/2-} groups in the metal tungstate. The emission spectra of the BaWO4:Ln3+ samples display the bands associated to the anion molecular complex (WO{4/2-}) and the f- f transitions of Ln3+. According to the emission spectra and the chromaticity coordinates (Commission internationale de l'éclairage, CIE), one can see that the BaWO4:Eu3+, BaWO4:Tb3+, and BaWO4:Dy3+ samples show emission in the red, green, and yellow region, respectively. The results show that the luminescence color can be altered by changing the Ln3+ doping in BaWO4 material.

Sun, Xiaoyu; Sun, Xiaodan; Li, Xingang; He, Jian; Wang, Binsheng

2014-09-01

423

Properties of Hot Pressed Titanium Alloy Powders for Cryogenic Applications.  

NASA Technical Reports Server (NTRS)

Evaluation of strength and toughness of hot-pressed titanium alloy powders at room and at cryogenic temperatures. The purpose was to determine how the mechanical properties of solid bodies formed from powder would compare with wrought specimens of the same size and with the same chemical analysis. It was found that of five titanium powder-making processes investigated, only the Rotating Electrode Process (REP) was capable of producing ELI-grade titanium alloy powder. Blocks hot-pressed from spherical REP powders had tensile properties equivalent to or better than those obtained from wrought bar.

Friedman, G. I.; Kazaroff, J. M.

1970-01-01

424

Counterflow diffusion flame synthesis of ceramic oxide powders  

DOEpatents

Ceramic oxide powders and methods for their preparation are revealed. Ceramic oxide powders are obtained using a flame process whereby one or more precursors of ceramic oxides are introduced into a counterflow diffusion flame burner wherein the precursors are converted into ceramic oxide powders. The nature of the ceramic oxide powder produced is determined by process conditions. The morphology, particle size, and crystalline form of the ceramic oxide powders may be varied by the temperature of the flame, the precursor concentration ratio, the gas stream and the gas velocity.

Katz, Joseph L. (Baltimore, MD); Miquel, Philippe F. (Towson, MD)

1997-01-01

425

The Manufacture of Spherical Titanium Alloy Powder in Plasma  

NASA Astrophysics Data System (ADS)

In this study, the preparation technology of spherical titanium alloy powder (tc4) was studied by using continuous induction plasma powder synthesis system. The flow-ability, particle size and impurity content of the powder before and after plasma treatment were measured and compared. The result showed that, by applying induction plasma preparation technology, the powder's flow-ability was improved by 20% while oxygen and carbon content were decreased significantly. The powder's sphericization rate and recovery rate were above 95% and 90% respectively with plasma spherical treatment.

Wei, Huang; Ziming, Chen; Yong, Liu; Fujun, Shang; Weiming, Huang

2014-08-01

426

[Making tablets of powdered milk and the physical properties].  

PubMed

Compressed baby milk powder has proven to be very convenient for parents due to the ease with which it can be handled, and the fact that use of a measuring scoop is not necessary. The purpose of this study was to develop a compressed baby milk powder and analyze the resulting physical properties. The basic production process consisted of the following steps: 1) molding milk powder by low compression pressure, 2) humidification at 25°C·97%RH and 3) drying with use of a desiccant. No chemical additives were used for solidification; therefore the chemical composition of the compressed milk powder is identical to the base milk powder. The important properties of the compressed milk powder are both ready solubility and the strength of the solid. The compressed milk powder obtained at low pressure was too brittle for practical use, but the strength was increased by humidification followed by drying. During the humidification process, the powder particles located close to the surface of the compressed milk powder partially dissolve resulting in bridging structures between the particles, leading to an increase in strength. Both specific surface area and the volume ratio of the compressed milk powder decreased. Testing showed that caking between the particles occurred following humidification, and that the volume of caking affected the ease with which the compressed milk powder dissolves in water. PMID:21963978

Shibata, Mitsuho; Otsubo, Kazumitsu; Nakane, Shota; Niwa, Toshiyuki; Danjo, Kazumi

2011-01-01

427

Increased conductivities of Cr doped Al2-xCrxO3 powders due to band gap narrowing  

NASA Astrophysics Data System (ADS)

A high Cr content in the synthesized Al2-xCrxO3 materials was achieved via a new synthesis route, the self propagating combustion method, for investigation of the effect of Cr substitution on the electrical, optical band gap and structural characteristics of the modified Al2O3 materials. X-ray diffraction (XRD) results showed that all the samples were pure and that Cr was successfully substituted in the crystal lattice. The cell parameters and volume are linearly dependent on the Cr content. AC impedance spectroscopy results show that conductivity of the Cr doped samples increases exponentially with Cr content. This is attributed to band gap narrowing of the Al2-xCrxO3 powders as obtained from UV-visible spectrophotometric studies.

Badar, Nurhanna; Kamarulzaman, Norlida; Rusdi, Roshidah; Abdul Aziz, Nor Diyana; Kun Fun, Hoong

2014-03-01

428

High Resolution Powder Diffraction and Structure Determination  

SciTech Connect

It is clear that high-resolution synchrotrons X-ray powder diffraction is a very powerful and convenient tool for material characterization and structure determination. Most investigations to date have been carried out under ambient conditions and have focused on structure solution and refinement. The application of high-resolution techniques to increasingly complex structures will certainly represent an important part of future studies, and it has been seen how ab initio solution of structures with perhaps 100 atoms in the asymmetric unit is within the realms of possibility. However, the ease with which temperature-dependence measurements can be made combined with improvements in the technology of position-sensitive detectors will undoubtedly stimulate precise in situ structural studies of phase transitions and related phenomena. One challenge in this area will be to develop high-resolution techniques for ultra-high pressure investigations in diamond anvil cells. This will require highly focused beams and very precise collimation in front of the cell down to dimensions of 50 {micro}m or less. Anomalous scattering offers many interesting possibilities as well. As a means of enhancing scattering contrast it has applications not only to the determination of cation distribution in mixed systems such as the superconducting oxides discussed in Section 9.5.3, but also to the location of specific cations in partially occupied sites, such as the extra-framework positions in zeolites, for example. Another possible application is to provide phasing information for ab initio structure solution. Finally, the precise determination of f as a function of energy through an absorption edge can provide useful information about cation oxidation states, particularly in conjunction with XANES data. In contrast to many experiments at a synchrotron facility, powder diffraction is a relatively simple and user-friendly technique, and most of the procedures and software for data analysis are familiar to laboratory diffractionists. This is reflected in the fact that there are already dedicated instruments for powder diffraction at a number of synchrotrons sources, including the NSLS, the Synchrotrons Radiation Source, Daresbury, the Photon Factory, Tsukuba and HASYLAB. In addition, most general purpose beamlines can be adapted for powder diffraction experiments fairly easily. Dedicated beamlines are also planned or under consideration at the next generation of synchrotrons sources, the European Synchrotron Radiation Facility, Grenoble, the Advanced Photon Source, Argonne, and the SPring-8 machine at Harima. These will be high brilliance sources with a much harder radiation spectrum that will offer many new possibilities for powder diffraction experiments, especially at energies above 10 keV.

Cox, D. E.

1999-04-23

429

Telecommunications\\/ transportation substitution and energy conservation Part 2  

Microsoft Academic Search

Part 1 of this article reviewed existing research both on attitudes toward telecommunications substitution for travel and on operational experiments with teleconferencing and telecommuting. Part 2 examines major factors influencing substitution, including government policy. It concludes that government policy can significantly facilitate telecommunications substitution for travel and, indeed, the achievement of any real measure of substitution may depend upon proactive

Kenneth L. Kraemer; John Leslie King

1982-01-01

430

Beta-substituted terthiophene [2]rotaxanes.  

PubMed

Two kinds of beta-substituted terthiophene [2]rotaxanes were synthesized using the host-guest pairs of the electron-deficient cyclophane cyclobis(paraquat-p-phenylene) (CBPQT(4+)) and the electron-rich terthiophenes with diethyleneglycol chains at the beta-position. One is made from the alpha-position non-substituted terthiophene (3 T-beta-Rx) and the other is made from the alpha-dibromo-substituted terthiophene (3 TBr-beta-Rx). The binding constants of the beta-substituted terthiophene threads were confirmed to be smaller than that of the alpha-substituted terthiophene analogue. By UV/Vis absorption measurements, we confirmed the charge-transfer (CT) band in the visible region with an extinction coefficient of approximately 10(2) (M(-1) cm(-1)). Strong, but not quantitative, quenching of the terthiophene fluorescence was confirmed for the [2]rotaxanes. Although the beta-substituted terthiophene thread was electrochemically polymerizable, the [2]rotaxane 3 T-beta-Rx was not polymerizable. This result indicates that the interlocked CBPQT(4+) macrocycle effectively suppresses the electrochemical polymerization of the terthiophene unit because electrostatic repulsive and steric effects of CBPQT(4+) hinder the dimerization of the terthiophene radical cations. In the electrochemical measurement, we confirmed the shift of the first reduction peak towards less negative potential compared to free CBPQT(4+) and the splitting of the second reduction peak. These electrochemical behaviors are similar to those observed for the highly-constrained [2]rotaxanes. The beta-substituted terthiophene [2]rotaxanes reported herein are important key compounds to prepare polythiophene polyrotaxanes. PMID:19308975

Ikeda, Taichi; Higuchi, Masayoshi; Kurth, Dirk G

2009-01-01

431

Influence of strontium for calcium substitution in bioactive glasses on degradation, ion release and apatite formation  

PubMed Central

Bioactive glasses are able to bond to bone through the formation of hydroxy-carbonate apatite in body fluids while strontium (Sr)-releasing bioactive glasses are of interest for patients suffering from osteoporosis, as Sr was shown to increase bone formation both in vitro and in vivo. A melt-derived glass series (SiO2–P2O5–CaO–Na2O) with 0–100% of calcium (Ca) replaced by Sr on a molar base was prepared. pH change, ion release and apatite formation during immersion of glass powder in simulated body fluid and Tris buffer at 37°C over up to 8 h were investigated and showed that substituting Sr for Ca increased glass dissolution and ion release, an effect owing to an expansion of the glass network caused by the larger ionic radius of Sr ions compared with Ca. Sr release increased linearly with Sr substitution, and apatite formation was enhanced significantly in the fully Sr-substituted glass, which allowed for enhanced osteoblast attachment as well as proliferation and control of osteoblast and osteoclast activity as shown previously. Studying the composition–structure–property relationship in bioactive glasses enables us to successfully design next-generation biomaterials that combine the bone regenerative properties of bioactive glasses with the release of therapeutically active Sr ions. PMID:21993007

Fredholm, Yann C.; Karpukhina, Natalia; Brauer, Delia S.; Jones, Julian R.; Law, Robert V.; Hill, Robert G.

2012-01-01

432

Zn- and Cu-substituted Co2Y hexagonal ferrites: Sintering behavior and permeability  

NASA Astrophysics Data System (ADS)

Y-type polycrystalline hexagonal ferrites Ba2Co2-x-yZnxCuyFe12O22 with 0?x?2 and 0?y?0.8 were prepared by the mixed-oxide route. Single phase Y-type ferrite powders were obtained after calcinations at 1000 °C. Samples sintered at 1200 °C show a permeability that increases with the substitution of Zn for Co and display maximum permeability of ?'=35 at 1 MHz for x=1.6 and y=0.4. A resonance frequency fr=500 MHz is observed for Zn-rich ferrites with y=0 and 0.4. The saturation magnetization increases with substitution of Zn for Co. Addition of Bi2O3 shifts the temperature of maximum shrinkage down to T?950 °C. Moreover, an increase of the Cu-concentration further lowers the sintering temperature to T?900 °C, enabling co-firing of the ferrites with Ag metallization for multilayer technologies. However, low-temperature firing reduces the permeability to ?'=10 and the resonance frequency is shifted to 1 GHz. Thus substituted hexagonal Y-type ferrites can be used as soft magnetic materials for multilayer inductors for high frequency applications.

Bierlich, S.; Töpfer, J.

2012-05-01

433

Influence of Magnesium Ion Substitution on Structural and Thermal Behavior of Nanodimensional Hydroxyapatite  

NASA Astrophysics Data System (ADS)

Hydroxyapatite (HA), incorporating small amount of magnesium, shows attractive biological performance in terms of improved bone metabolism, osteoblast and osteoclast activity, and bone in-growth. This article reports a systematic investigation on the influence of magnesium (Mg) substitution on structural and thermal behavior of nanodimensional HA. HA and Mg-substituted HA nanopowders were synthesized through sol-gel route. The morphology and size of nanopowders were characterized by transmission electron microscopy. The BET surface area was evaluated from N2 adsorption isotherms. Structural analysis and thermal behavior were investigated by means of Fourier transform infrared spectroscopy, x-ray diffraction, thermogravimetry, and differential thermal analysis. As-synthesized powders consisted of flake-like agglomerates of HA and calcium-deficient HA. The incorporation of magnesium in HA resulted in decrease of crystallite size, crystallinity, and lattice parameters a and c and increase in BET surface area. ?-tricalcium phosphate formation occured at lower calcination temperature in Mg-substituted HA than HA.

Batra, Uma; Kapoor, Seema; Sharma, Sonia

2013-06-01

434

Influence of strontium for calcium substitution in bioactive glasses on degradation, ion release and apatite formation.  

PubMed

Bioactive glasses are able to bond to bone through the formation of hydroxy-carbonate apatite in body fluids while strontium (Sr)-releasing bioactive glasses are of interest for patients suffering from osteoporosis, as Sr was shown to increase bone formation both in vitro and in vivo. A melt-derived glass series (SiO(2)-P(2)O(5)-CaO-Na(2)O) with 0-100% of calcium (Ca) replaced by Sr on a molar base was prepared. pH change, ion release and apatite formation during immersion of glass powder in simulated body fluid and Tris buffer at 37°C over up to 8 h were investigated and showed that substituting Sr for Ca increased glass dissolution and ion release, an effect owing to an expansion of the glass network caused by the larger ionic radius of Sr ions compared with Ca. Sr release increased linearly with Sr substitution, and apatite formation was enhanced significantly in the fully Sr-substituted glass, which allowed for enhanced osteoblast attachment as well as proliferation and control of osteoblast and osteoclast activity as shown previously. Studying the composition-structure-property relationship in bioactive glasses enables us to successfully design next-generation biomaterials that combine the bone regenerative properties of bioactive glasses with the release of therapeutically active Sr ions. PMID:21993007

Fredholm, Yann C; Karpukhina, Natalia; Brauer, Delia S; Jones, Julian R; Law, Robert V; Hill, Robert G

2012-05-01

435

Uniformly accelerated black holes  

NASA Astrophysics Data System (ADS)

The static and stationary C metric are examined in a generic framework and their interpretations studied in some detail, especially those with two event horizons, one for the black hole and another for the acceleration. We find that (i) the spacetime of an accelerated static black hole is plagued by either conical singularities or a lack of smoothness and compactness of the black hole horizon, (ii) by using standard black hole thermodynamics we show that accelerated black holes have a higher Hawking temperature than Unruh temperature of the accelerated frame, and (iii) the usual upper bound on the product of the mass and acceleration parameters (<1/27) is just a coordinate artifact. The main results are extended to accelerated rotating black holes with no significant changes.

Letelier, Patricio S.; Oliveira, Samuel R.

2001-09-01

436

Extremal Hairy Black Holes  

E-print Network

We consider a gravitating system consisting of a scalar field minimally coupled to gravity with a self-interacting potential and an U(1) electromagnetic field. Solving the coupled Einstein-Maxwell-scalar system we find exact hairy charged black hole solutions with the scalar field regular everywhere. We go to the zero temperature limit and we study the effect of the scalar field on the near horizon geometry of an extremal black hole. We find that except a critical value of the charge of the black hole there is also a critical value of the charge of the scalar field beyond of which the extremal black hole is destabilized. We study the thermodynamics of these solutions and we find that if the space is flat then at low temperature the Reissner-Nordstr\\"om black hole is thermodynamically preferred, while if the space is AdS the hairy charged black hole is thermodynamically preferred at low temperature.

Gonzalez, P A; Saavedra, Joel; Vasquez, Yerko

2014-01-01

437

Carbon black enriched combustion  

SciTech Connect

A process for combustion of carbon black enriched gaseous hydrocarbon fuels is described comprising: entraining a plurality of carbon black particles in a carrier fluid, forming a carbon black/carrier fluid mixture; injecting said carbon black/carrier fluid mixture through a center nozzle of a fluid injector into a combustion chamber, said fluid injector having an outer nozzle concentrically disposed around said center nozzle forming an annular chamber between said center nozzle and said outer nozzle; injecting at least a first portion of a gaseous hydrocarbon fuel through said annular chamber into said combustion chamber forming a carbon black enriched gaseous hydrocarbon fuel; mixing said carbon black enriched gaseous hydrocarbon fuel with combustion air, forming a fuel/air mixture; and igniting said fuel/air mixture.

Joshi, M.L.; Tester, M.E.

1993-06-29

438

Bicycling Black Rings  

E-print Network

We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

Henriette Elvang; Maria J. Rodriguez

2007-12-14

439

Bumpy black holes  

E-print Network

We study six-dimensional rotating black holes with bumpy horizons: these are topologically spherical, but the sizes of symmetric cycles on the horizon vary non-monotonically with the polar angle. We construct them numerically for the first three bumpy families, and follow them in solution space until they approach critical solutions with localized singularities on the horizon. We find strong evidence of the conical structures that have been conjectured to mediate the transitions to black rings, to black Saturns, and to a novel class of bumpy black rings. For a different, recently identified class of bumpy black holes, we find evidence that this family ends in solutions with a localized singularity that exhibits apparently universal properties, and which does not seem to allow for transitions to any known class of black holes.

Roberto Emparan; Pau Figueras; Marina Martinez

2014-10-17

440

Bumpy black holes  

E-print Network

We study six-dimensional rotating black holes with bumpy horizons: these are topologically spherical, but the sizes of symmetric cycles on the horizon vary non-monotonically with the polar angle. We construct them numerically for the first three bumpy families, and follow them in solution space until they approach critical solutions with localized singularities on the horizon. We find strong evidence of the conical structures that have been conjectured to mediate the transitions to black rings, to black Saturns, and to a novel class of bumpy black rings. For a different, recently identified class of bumpy black holes, we find evidence that this family ends in solutions with a localized singularity that exhibits apparently universal properties, and which does not seem to allow for transitions to any known class of black holes.

Emparan, Roberto; Martinez, Marina

2014-01-01

441

Extremal hairy black holes  

NASA Astrophysics Data System (ADS)

We consider a gravitating system consisting of a scalar field minimally coupled to gravity with a self-interacting potential and an U(1) electromagnetic field. Solving the coupled Einstein-Maxwell-scalar system we find exact hairy charged black hole solutions with the scalar field regular everywhere. We go to the zero temperature limit and we study the effect of the scalar field on the near horizon geometry of an extremal black hole. We find that except a critical value of the charge of the black hole there is also a critical value of the charge of the scalar field beyond of which the extremal black hole is destabilized. We study the thermodynamics of these solutions and we find that if the space is flat then the Reissner-Nordström black hole is thermodynamically preferred, while if the space is AdS the hairy charged black hole is thermodynamically preferred at low temperature.

González, P. A.; Papantonopoulos, Eleftherios; Saavedra, Joel; Vásquez, Yerko

2014-11-01

442

Quantization of Black Holes  

E-print Network

We show that black holes can be quantized in an intuitive and elegant way with results in agreement with conventional knowledge of black holes by using Bohr's idea of quantizing the motion of an electron inside the atom in quantum mechanics. We find that properties of black holes can be also derived from an Ansatz of quantized entropy $\\Delta S=4\\pi k {\\Delta R / \\lambdabar}$, which was suggested in a previous work to unify the black hole entropy formula and Verlinde's conjecture to explain gravity as an entropic force. Such an Ansatz also explains gravity as an entropic force from quantum effect. This suggests a way to unify gravity with quantum theory. Several interesting and surprising results of black holes are given from which we predict the existence of primordial black holes ranging from Planck scale both in size and energy to big ones in size but with low energy behaviors.

Xiao-Gang He; Bo-Qiang Ma

2010-03-12

443

The Black Family as Educator.  

ERIC Educational Resources Information Center

The black family is the primary socializing agent of the black child and, thus, the primary educator. The culture of blacks in America, in which the child is steeped, is unique, complex and rich-the result of a convergence and fusion of African, American, and European influences. In its education of the black child, the black family must deal,…

Wallace, Joan

444

Black Holes (With 16 figures)  

Microsoft Academic Search

Astrophysics of Black Holes Introduction The Origin of Stellar Black Holes A Nonrotating Black Hole Introduction Schwarzschild Gravitational Field Motion of Photons Along the Radial Direction Radial Motion of Nonrelativistic Particles The Puzzle of the Gravitational Radius R and T Regions Two Types of T-Regions Gravitational Collapse and White Holes Eternal Black Hole? Black Hole Celestial Mechanics Circular Motion Around

Igor Novikov

1995-01-01

445

Blacks, Crime, and American Culture  

Microsoft Academic Search

Attempts to understand crime patterns among blacks in the United States have systematically failed to consider the impact of slavery and resultant racist policies on black self-esteem. This paper explores the thesis that cultural domination was fundamentally more damaging than economic domination to black self-esteem. The ruth less attacks on blacks and black culture, usually justified by legal interpretations by

John A. Davis

1976-01-01

446

What Black Educators are Saying.  

ERIC Educational Resources Information Center

Contents of this book are comprised of five groups of articles: Part I. The Black Educator: "Education for black humanism; a way of approaching it," Preston Wilcox; "The new black dimension in our society," Olivia Pearl Stokes; "The black teacher and black Power," Leslie Campbell; and, "The difference," Leslie Campbell. Part II. The White…

Wright, Nathan, Jr., Ed.

447

Azo Group-Assisted Nucleophilic Aromatic Substitutions in Haloarene Derivatives: Preparation of Substituted  

E-print Network

Azo Group-Assisted Nucleophilic Aromatic Substitutions in Haloarene Derivatives: Preparation piotr@ctrvax.vanderbilt.edu Received July 25, 2003 Aryldiazo substituents were used in nucleophilic aromatic substitution reactions of halogens. The Ph-NdN- group activates ortho fluorine atoms toward

Kaszynski, Piotr

448

Regioselective nucleophilic substitution reaction of meso-hexakis(pentafluorophenyl) substituted [26]hexaphyrin  

Microsoft Academic Search

Reaction of various alkoxides led to the selective replacement of the p-fluorine substituents of meso-hexakis(pentafluorophenyl) substituted [26]hexaphyrin. Reaction with isopropyl amine gave meso-hexakis(4-isopropylamino-2,3,5,6-tetrafluorophenyl) substituted [28]hexaphyrin.

Masaaki Suzuki; Soji Shimizu; Ji-Young Shin; Atsuhiro Osuka

2003-01-01

449

Black Branes as Piezoelectrics  

NASA Astrophysics Data System (ADS)

We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

Armas, Jay; Gath, Jakob; Obers, Niels A.

2012-12-01

450

Black Box Software Testing  

NSDL National Science Digital Library

The Black Box Software Testing Collection provides instructional materials (lectures, slides and videos) to teach black box software testing. Black box testing is the craft of testing a program from the external view. Materials in the collection are organized into self-contained sections that focus on foundations of software testing and specific, well-known software testing techniques. Some of the materials are used in professional development courses taught by Florida Institute of Technology and the Association for Software Testing.

2011-05-19

451

TST Dual Black Hole  

Microsoft Academic Search

The sequence of intertwined T-S-T duality transformations acting on the 4D static uncharged black hole leads to a black hole background with horizon and singularity exchanged. It is shown that this space-time is extendible too. In particular we will see that a string moving into a black hole is dual to a string leaving a white hole. That offers the

Björn Andreas

1997-01-01

452

The Nearest Black Holes  

NASA Technical Reports Server (NTRS)

The goal of this program is to study black holes, both in our Galaxy and in nearby galaxies. We aim to study both 'stellar mass' x-ray binaries containing black holes (both in our Galaxy and in nearby galaxies), and super-massive black holes in nearby galaxies. This program facilitates this study by funding related travel, computer equipment, and partial salary for a post-doc.

Oliversen, Ronald J. (Technical Monitor); Garcia, M.

2003-01-01

453

Black branes as piezoelectrics.  

PubMed

We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six. PMID:23368298

Armas, Jay; Gath, Jakob; Obers, Niels A

2012-12-14

454

Evaluation of Raney-nickel cathodes prepared with aluminum powder and titanium hydride powder  

SciTech Connect

Raney-nickel (Ni) cathodes were prepared on nickel wire from aluminum powder and titanium hydride powder by heat-treatment. The influence of the addition of titanium to the Raney-Ni electrode on the polarization characteristics of the hydrogen evolution reaction was studied in 1 M NaOH at 303 K. Although the coated layer was composed of nickel with a small amount of aluminum and titanium, the titanium was enriched the most. The relative surface area of the Raney-Ni cathodes was about 3500 independent of the presence of titanium, but titanium could decrease the hydrogen overpotential.

Tanaka, Shinichi [Tokyo Metropolitan Industrial Technology Research Inst. (Japan)] [Tokyo Metropolitan Industrial Technology Research Inst. (Japan); [Kyoto Univ. (Japan). Inst. of Advanced Energy; Hirose, Norimitsu; Tanaki, Toshiyuki [Tokyo Metropolitan Eastern District Small and Medium-Sized Business Promotion Center (Japan)] [Tokyo Metropolitan Eastern District Small and Medium-Sized Business Promotion Center (Japan)

1999-07-01

455

Charged Lifshitz black holes  

NASA Astrophysics Data System (ADS)

We investigate modifications of the Lifshitz black hole solutions due to the presence of Maxwell charge in higher dimensions for arbitrary z and any topology. We find that the behavior of large black holes is insensitive to the topology of the solutions, whereas for small black holes significant differences emerge. We generalize a relation previously obtained for neutral Lifshitz black branes, and study more generally the thermodynamic relationship between energy, entropy, and chemical potential. We also consider the effect of Maxwell charge on the effective potential between objects in the dual theory.

Dehghani, M. H.; Mann, R. B.; Pourhasan, R.

2011-08-01

456

Accreting Black Holes  

E-print Network

I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these interactions. Larger global magnetohydrodynamic simulations as well as simulations incorporating plasma microphysics and full radiation hydrodynamics will be needed to unravel some of the current mysteries of black hole accretion.

Begelman, Mitchell C

2014-01-01

457

Artificial black holes  

E-print Network

We study black holes for the linear hyperbolic equations describing the wave propagation in the moving medium. Such black holes are called artificial since the Lorentz metric associated with the hyperbolic equation does not necessary satisfies the Einstein equations. Artificial black holes also arise when we consider perturbations of the Einstein equations. In this paper we review author's results of [E2] and [E3] on the existence and the stability of black holes for the stationary wave equations in two space dimensions, and in the axisymmetric case.

Gregory Eskin

2011-05-10

458

A Black Hole Levitron  

E-print Network

We study the problem of spatially stabilising four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes kept in external fields we find that taking a continuum limit of Denef et al's multi-center solutions provides a supergravity description of such backgrounds within which a black hole can be trapped in a given volume. This is realised by levitating a black hole over a magnetic dipole base. We comment on how such a construction resembles a mechanical Levitron.

Xerxes D. Arsiwalla; Erik P. Verlinde

2009-02-02

459

Antigravity and black holes  

E-print Network

We speculate about impact of antigravity (i.e. gravitational repulsion between matter and antimatter) on the creation and emission of particles by a black hole. If antigravity is present a black hole made of matter may radiate particles as a black body, but this shouldn't be true for antiparticles. It may lead to radical change of radiation process predicted by Hawking and should be taken into account in preparation of the attempt to create and study mini black holes at CERN. Gravity, including antigravity is more than ever similar to electrodynamics and such similarity with a successfully quantized interaction may help in quantization of gravity.

Hajdukovic, D

2006-01-01

460

Black hole thermodynamics  

NASA Astrophysics Data System (ADS)

The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity. In this paper, will review the discovery of black hole thermodynamics and summarize the many independent ways of obtaining the thermodynamic and (perhaps) statistical mechanical properties of black holes. I will then describe some of the remaining puzzles, including the nature of the quantum microstates, the problem of universality, and the information loss paradox.

Carlip, S.

2014-10-01

461

BlackBerry  

Microsoft Academic Search

\\u000a This chapter will discuss how to build native applications for BlackBerry smartphones. The BlackBerry is a product of Research\\u000a in Motion (RIM), a public company based in Waterloo, Ontario. Founded in 1984, RIM released its first BlackBerry smartphone\\u000a in 2002. Optimized for push email and with an easy-to-use QWERTY keyboard, the BlackBerry became the “gold standard” in smartphones\\u000a for business

Sarah Allen; Vidal Graupera; Lee Lundrigan

462

Black Hole Thermodynamics  

E-print Network

The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity. In this chapter I will review the discovery of black hole thermodynamics and summarize the many independent ways of obtaining the thermodynamic and (perhaps) statistical mechanical properties of black holes. I will then describe some of the remaining puzzles, including the nature of the quantum microstates, the problem of universality, and the information loss paradox.

Carlip, S

2014-01-01

463

Black Hole Thermodynamics  

E-print Network

The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity. In this chapter I will review the discovery of black hole thermodynamics and summarize the many independent ways of obtaining the thermodynamic and (perhaps) statistical mechanical properties of black holes. I will then describe some of the remaining puzzles, including the nature of the quantum microstates, the problem of universality, and the information loss paradox.

S. Carlip

2014-10-06

464

Syntactical Speech Patterns of Black Children from a Depressed Urban Area: Educators Look at Linguistic Findings.  

ERIC Educational Resources Information Center

The syntactical speech characteristics of black children living in depressed areas of an Eastern city were compared with the eight identified by Baratz, i.e., absence of "s" in the third person singular, zero copula, double negation and "ain't," zero past marker, zero possessive marker, zero plural marker, the substitution of "did" or "can" for…

Gantt, Walter N.; Wilson, Robert M.

465

Modified Pechini synthesis of tricalcium aluminate powder  

SciTech Connect

Tricalcium aluminate (Ca{sub 3}Al{sub 2}O{sub 6}-C{sub 3}A) was obtained by a modified Pechini synthesis in order to eliminate successive thermal treatments and intermediate grinding usually performed between the two sintering steps and in order to reduce the sintering temperature. Our results indicated that pure C{sub 3}A was obtained, by a single step thermal treatment at 1300 Degree-Sign C for 4 h and 1350 Degree-Sign C for 1 h. The synthesis was confirmed by XRD, FT-IR and free lime analyses. The morphology of synthesised C{sub 3}A was assessed by electron microscopy (SEM and TEM, HRTEM) and it was observed a high tendency of the particles to form aggregates and the individual particles seem to be single crystals. The bioactivity was assessed by specimen soaking in simulated body fluid (SBF) for 7 days; the hydrate (i.e. 3CaO Bullet-Operator Al{sub 2}O{sub 3} Bullet-Operator 6H{sub 2}O formed at the C{sub 3}A surface), can act as nucleation centers for the resulted phosphate phases. - Highlights: Black-Right-Pointing-Pointer A modified Pechini synthesis was used for obtained of tricalcium aluminate. Black-Right-Pointing-Pointer C{sub 3}A was obtained at 1300 Degree-Sign C/4 h and 1350 Degree-Sign C/1 h. Black-Right-Pointing-Pointer Were eliminated successive thermal treatments and intermediate grinding. Black-Right-Pointing-Pointer The morphology of synthesised C{sub 3}A was assessed by electron microscopy (SEM, TEM). Black-Right-Pointing-Pointer Was observed a high tendency of the particles to form aggregates.

Voicu, Georgeta, E-mail: getav2001@yahoo.co.uk; Ghitulica, Cristina Daniela; Andronescu, Ecaterina

2012-11-15

466

Nonlinear self-adjointness through differential substitutions  

NASA Astrophysics Data System (ADS)

It is known (Ibragimov, 2011; Galiakberova and Ibragimov, 2013) [14,18] that the property of nonlinear self-adjointness allows to associate conservation laws of the equations under study, with their symmetries. In this paper we show that, even when the equation is nonlinearly self-adjoint with a non differential substitution, finding the explicit form of the differential substitution can provide new conservation laws associated to its symmetries. By using the general theorem on conservation laws (Ibragimov, 2007) [11] and the property of nonlinear self-adjointness we find some new conservation laws for the modified Harry-Dym equation. By using a differential substitution we construct a conservation law for the Harry-Dym equation, which has not been derived before using Ibragimov method.

Gandarias, M. L.

2014-10-01

467

Substituting telecommunications for travel - Feasible or desirable  

NASA Technical Reports Server (NTRS)

This paper reviews recent advances in telecommunications and examines the detailed structure of travel to estimate the feasibility of substituting telecommunications for various travel objectives. The impact of travel is analyzed from a social, economic, energy, and pollution standpoint to assess the desirability of substitution. Perhaps 35-50% of the nation's travel could, in theory, be replaced by very advanced telecommunications (such as a much improved large-screen teleconferencing network), but public resistance would be massive. Much economic dislocation would result since, for example, over 25% of retail sales are travel-related. The energy savings would be modest since only 25% of the nation's energy is consumed by transportation. However, all pollution would be reduced substantially since transportation accounts for 75% of the carbon monoxide, 60% of the hydrocarbon, and 55% of the nitrogen oxide pollution in the nation. Problems related to the implementation of large-scale substitution are discussed.

Van Vleck, E. M.

1974-01-01

468

Low-Cobalt Powder-Metallurgy Superalloy  

NASA Technical Reports Server (NTRS)

Highly-stressed jet-engine parts made with less cobalt. Udimet 700* (or equivalent) is common nickel-based superalloy used in hot sections of jet engines for many years. This alloy, while normally used in wrought condition, also gas-atomized into prealloyed powder-metallurgy (PM) product. Product can be consolidated by hot isostatically pressing (HIPPM condition) and formed into parts such as turbine disk. Such jet-engine disks "see" both high stresses and temperatures to 1,400 degrees F (760 degrees C).

Harf, F. H.

1986-01-01

469

Effective temperature of an aging powder.  

PubMed

The aging dynamics and the fluctuation-dissipation relation between the spontaneous diffusion induced by a random noise and the drift motion induced by a small stirring force are numerically investigated in a 3D schematic model of compacting powder: a gravity-driven lattice-gas with purely kinetic constraints. The compaction dynamics is characterized by a super-aging behavior and, in analogy with glasses, exhibits a purely dynamical time-scale-dependent effective temperature. A simple experiment to measure this quantity is suggested. PMID:11415060

Sellitto, M

2001-06-01

470

Ampicillin Trihydrate from Synchrotron Powder Diffraction Data  

SciTech Connect

The crystal structure of ampicillin trihydrate {l_brace}systematic name: 6-[D(-)-{alpha}-aminophenylacetamido]penicillanic acid trihydrate{r_brace}, C{sub 16}H{sub 19}N{sub 3}O{sub 4}S{center_dot}3H{sub 2}O, a broad-spectrum {beta}-lactam antibiotic of the aminopenicillin type, has been determined from synchrotron X-ray powder diffraction data. The three water molecules form an infinite hydrogen-bonded chain through the crystal structure, with hydrogen bonds to the NH{sub 3}{sup +}, COO{sup -}, C{double_bond}O and NH groups of the ampicillin molecules.

Burley,J.; van de Streek, J.; Stephens, P.

2006-01-01

471

Laser production of articles from powders  

DOEpatents

Method and apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. Preferably the tool path and other parameters of the deposition process are established using computer-aided design and manufacturing techniques. A controller comprised of a digital computer directs movement of a deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which a deposition head which delivers the laser beam and powder to the deposition zone moves along the tool path.

Lewis, Gary K. (Los Alamos, NM); Milewski, John O. (Santa Fe, NM); Cremers, David A. (Los Alamos, NM); Nemec, Ronald B. (White Rock, NM); Barbe, Michael R. (White Rock, NM)

1998-01-01

472

Laser production of articles from powders  

DOEpatents

Method and apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. Preferably the tool path and other parameters of the deposition process are established using computer-aided design and manufacturing techniques. A controller comprised of a digital computer directs movement of a deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which a deposition head which delivers the laser beam and powder to the deposition zone moves along the tool path. 20 figs.

Lewis, G.K.; Milewski, J.O.; Cremers, D.A.; Nemec, R.B.; Barbe, M.R.

1998-11-17

473

Powder and particulate production of metallic alloys  

NASA Technical Reports Server (NTRS)

Developments of particulate metallurgy of alloyed materials where the final products is a fully dense body are discussed. Particulates are defined as powders, flakes, foils, silvers, ribbons and strip. Because rapid solidification is an important factor in particulate metallurgy, all of the particulates must have at least one dimension which is very fine, sometimes as fine as 10 to 50 microns, but move typically up to several hundred microns, provided that the dimension permits a minimum solidification rate of at least 100 K/s.

Grant, N. J.

1982-01-01

474

The Meaning of Black Music  

ERIC Educational Resources Information Center

Discusses the definition of black music in terms of the history and cultural background of black people, places it within the larger scope of western music, and suggests its survival value with respect to black people. (JM)

Byrd, Donald

1972-01-01

475

The Black Caucus Votes No  

ERIC Educational Resources Information Center

From a statement on media practices regarding the dissemination of a wide range of documentary and other programming about the state of Black America without any input, consultation, or decisions by black Americans, issued by the Congressional Black Caucus. (JM)

Urban Review, 1972

1972-01-01

476

Soluble N-Substituted Organosilane Polybenzimidazoles  

SciTech Connect

Six organosilane derivatives were synthesized, and are more soluble in common organic solvents (tetrahydrofuran and chloroform) than the parent polybenzimidazole. Our polymer modification pathway provides a straightforward synthesis that can be carried out at room temperature and give reasonable yields. Solution 1H NMR spectra of both the parent and deprotonated polybenzimidazoles are reported. Based upon the NMR analysis in CDCl3, nearly all of the benzimidazole N-H positions are substituted by the organosilane moieties. Some of the modified polymers have similar thermal properties compared to the parent polymer, and the average molecular weights are higher for the substituted polybenzimidazoles than the parent PBI.

Klaehn, J. R.; Luther, T. A.; Orme, C. J.; Jones, M. G.; Wertsching, A. K.; Peterson, E. S.

2007-10-01

477

Color and chemical stability of a variety of anthocyanins and ascorbic acid in solution and powder forms.  

PubMed

The color and chemical stabilities of six anthocyanins, including cyanidin 3-glucoside, highly purified and present in semipurified extracts (also containing other anthocyanins) from grape pomace, purple corn, and black rice, were determined in combination with ascorbic acid in solutions at differing pH values (3.0 and 4.0) and temperatures (6-40 °C) and lyophilized powders at different relative humidities (43-98% RH). Color and chemical changes were analyzed using CIELAB measurements and HPLC, respectively. In liquids, stability was inversely related to increasing pH and temperature; for powders, stability was inversely related to RH. The mutual destruction of anthocyanins and ascorbic acid in solution was confirmed, with unexpected new findings showing no significant stabilizing/destabilizing effect based upon anthocyanin structure, including differing flavylium core (three types) and type of acylation (two aliphatic, one cinnamic acid), or final extract purity. PMID:23534933

West, Megan E; Mauer, Lisa J

2013-05-01

478

Black hole excision for dynamic black holes  

NASA Astrophysics Data System (ADS)

We extend the previous work on 3D black hole excision to the case of distorted black holes, with a variety of dynamic gauge conditions that respond naturally to the spacetime dynamics. We show that in evolutions of highly distorted, rotating black holes, the combination of excision and the gauge conditions we use is able to drive the coordinates to a frame in which the system looks almost static at late times. Further, we show for the first time that one can extract accurate wave forms from these simulations, with the full machinery of excision and dynamic gauge conditions. The evolutions can be carried out for a long time, far exceeding the longevity and accuracy of better resolved 2D codes.

Alcubierre, Miguel; Brügmann, Bernd; Pollney, Denis; Seidel, Edward; Takahashi, Ryoji

2001-09-01

479

Method for preparing metal powder, device for preparing metal powder, method for processing spent nuclear fuel  

DOEpatents

A method for producing metal powder is provided the comprising supplying a molten bath containing a reducing agent, contacting a metal oxide with the molten bath for a time and at a temperature sufficient to reduce the metal in the metal oxide to elemental metal and produce free oxygen; and isolating the elemental metal from the molten bath.

Park, Jong-Hee (Clarendon Hills, IL)

2011-11-29

480

The preference of protein powders among adult male and females: A protein powder taste study  

Microsoft Academic Search

Protein is essential in one's diet because it is an important component in many organs and tissues throughout the body. Athletes ingest protein in order to stimulate protein synthesis and increase lean muscle mass. In order to assist with obtaining adequate amounts of protein, athletes and bodybuilders purchase supplemental protein in the form of protein powders. Protein metabolism and digestion

Joshua Manter

2010-01-01

481

Numerical investigation of coarse powder and air flow in an electrostatic powder coating process  

Microsoft Academic Search

The work presented here reports on the numerical simulation of an electrostatic powder coating process that uses a commercial computational fluid dynamic code, FLUENT v6.1. The purpose of this study was to understand the gas and particle flow fields inside a coating booth under given operating conditions and the effect of particle sizes on its trajectories and the final coating

U. Shah; J. Zhu; C. Zhang; J NOTHERSENIOR

2006-01-01

482

Physical properties of yoghurt powder produced by spray drying.  

PubMed

The study is an extension of an optimization study, which was planned to determine the optimum spray drying conditions (the feed, outlet and inlet air temperatures) for producing yoghurt powder. The resulting yoghurt powder at each condition was subjected to the measurement of physical properties, moisture content, and reconstitution properties. All the reconstitution properties of yoghurt powders produced under 20 different spray drying conditions according to CCRD experimental design were affected by the drying outlet temperature only. Furthermore, the bulk (bulk and tapped densities, porosity, flowability, hygroscopicity and degree of caking) and particle properties (particle size distribution, particle density and morphology) of yoghurt powder obtained from optimum spray drying conditions were also determined. The bulk, tapped and particle densities of yoghurt powder were 538, 746 and 1177 kg/m(3), respectively. The mean diameter (D4.3) and the span value of yoghurt powder were 3.053 and 2.487 ?m, respectively. PMID:24966433

Koç, Banu; Sakin-Y?lmazer, Melike; Kaymak-Ertekin, Figen; Balk?r, P?nar

2014-07-01

483

Amorphous powders of Al-Hf prepared by mechanical alloying  

SciTech Connect

We synthesized amorphous Al/sub 50/Hf/sub 50/ alloy powder by mechanically alloying an equimolar mixture of crystalline powders of Al and Hf using hexane as a dispersant. We characterized the powder as a function of mechanical-alloying time by scanning electron microscopy, x-ray diffraction, and differential scanning calorimetry. Amorphous Al/sub 50/Hf/sub 50/ powder heated at 10 K s/sup /minus/1/ crystallizes polymorphously at 1003 K into orthorhombic AlHf (CrB-type structure). During mechanical alloying, some hexane decomposes and hydrogen and carbon are incorporated into the amorphous alloy powder. The hydrogen can be removed by annealing the powder by hot pressing at a temperature approximately 30 K below the crystallization temperature. The amorphous compacts have a diamond pyramidal hardness of 1025 DPH. 24 refs., 7 figs., 1 tab.

Schwarz, R.B.; Hannigan, J.W.; Sheinberg, H.; Tiainen, T.

1988-01-01

484

Printed circuit board metal powder filters for low electron temperatures  

NASA Astrophysics Data System (ADS)

We report the characterisation of printed circuit boards (PCB) metal powder filters and their influence on the effective electron temperature which is as low as 22 mK for a quantum dot in a silicon MOSFET structure in a dilution refrigerator. We investigate the attenuation behaviour (10 MHz-20 GHz) of filter made of four metal powders with a grain size below 50 ?m. The room-temperature attenuation of a stainless steel powder filter is more than 80 dB at frequencies above 1.5 GHz. In all metal powder filters, the attenuation increases with temperature. Compared to classical powder filters, the design presented here is much less laborious to fabricate and specifically the copper powder PCB-filters deliver an equal or even better performance than their classical counterparts.

Mueller, Filipp; Schouten, Raymond N.; Brauns, Matthias; Gang, Tian; Lim, Wee Han; Lai, Nai Shyan; Dzurak, Andrew S.; van der Wiel, Wilfred G.; Zwanenburg, Floris A.

2013-04-01

485

Black Hole Shadows of Charged Spinning Black Holes  

E-print Network

We propose a method for measuring the black hole charge by imaging a black hole shadow in a galactic center by future interferometers. Even when the black hole is uncharged, it is possible to confirm the charge neutrality by this method. We first derive the analytic formulae of the black hole shadow in an optically thin medium around a charged spinning black hole, and then investigate how contours of the black hole shadow depend on the spin and the charge of the black hole for several inclination angles between the rotation axis of the black hole and the observer. This method only assumes stationary black hole and general relativity. By fitting the formula of the contours of the shadow to the observed image of the shadow, in addition to the black hole charge, one can also determine the black hole spin and the inclination angle without any degeneracy among the charge, the spin, and the inclination angle unless the inclination angle is null.

Rohta Takahashi

2005-05-16

486

The Black Woman's Burden  

ERIC Educational Resources Information Center

Not even the first lady of the most powerful nation in the world is immune to stereotypes that have plagued Black women since first setting foot on American soil. Stereotypes of being the "angry Black woman" and curiosity about differences in appearance still persist from the academy to 1600 Pennsylvania Ave. As African-American women rise in…

Hayes, Dianne

2012-01-01

487

Uniformly accelerated black holes  

Microsoft Academic Search

The static and stationary C metric are examined in a generic framework and their interpretations studied in some detail, especially those with two event horizons, one for the black hole and another for the acceleration. We find that (i) the spacetime of an accelerated static black hole is plagued by either conical singularities or a lack of smoothness and compactness

Patricio S. Letelier; Samuel R. Oliveira

2001-01-01

488

Hypercylindrical black holes  

SciTech Connect

We show that the Schwarzschild black hole extended to five dimensions by the addition of an extra dimension is stable against linearized perturbations of the metric; thus the topology of the horizon can be thought of as an extra black-hole hair.

Gregory, R.; Laflamme, R.

1988-01-15

489

Black Families. Interdisciplinary Perspectives.  

ERIC Educational Resources Information Center

Since the early 1960s, the black family has been characterized as pathological. This six-part collection of 18 research studies presents alternative approaches to understanding the special characteristics of black families. Part I, "Theoretical and Methodological Perspectives," comprises a comparison of the pioneering work of W. E. B. Du Bois and…

Cheatham, Harold E., Ed.; Stewart, James B., Ed.

490

The Black College Mystique  

ERIC Educational Resources Information Center

This study compares the culture of black colleges and universities a generation ago with those that exist today, and makes projections into the future, based on a comprehensive review of professional literature and an analysis of the management skills of contemporary black college leaders. The book considers the assets and liabilities of…

Willie, Charles V.; Reddick, Richard J.; Brown, Ronald

2005-01-01

491

Black Studies Year One.  

ERIC Educational Resources Information Center

Though Dubois tried to begin a series of scientific studies on the Negro problem in America more than 70 years ago, only recently have attempts been made to present a true history of the Black man in institutions of higher learning. Until that time, the experience of the Black man was defined in Euro-American terms, or in most cases was completely…

Long, Richard A.

492

State of Black Cincinnati.  

ERIC Educational Resources Information Center

The results of a survey conducted in the black community of Cincinnati, Ohio, are presented in this report. The survey sought to determine the perceptions, views, and attitudes of the city's black citizens regarding key social and economic issues. The report presents findings in the following areas: (1) education, including issues of…

Urban League of Greater Cincinnati, OH.

493

Semiconducting black phosphorus  

Microsoft Academic Search

Black phosphorus is a narrow-gap semiconductor newly attracting attention because of recent success in growing single crystals at a high temperature under a high pressure. This review covers recent research work on the preparation, the crystal structure, the band structure, the electrical and optical properties, and the superconductivity of black phosphorus.

A. Morita

1986-01-01

494

Learning Mathematics while Black  

ERIC Educational Resources Information Center

While research by scholars has contributed greatly to an emerging knowledge base on Black children and mathematics, there continues to be a dire need for insightful research that de-centers longstanding accounts that have contributed to the construction of Black children as mathematically illiterate and as less than ideal learners relative to…

Martin, Danny Bernard

2012-01-01

495

Cultural Vignette: Black Americans.  

ERIC Educational Resources Information Center

Developed as part of a multicultural research project conducted in the San Diego Community College District, this booklet presents the findings of an eight-member research team about various elements of Black American culture and history. The booklet begins with a brief history of Black Americans from the time of the arrival of the first slaves to…

Bell, Ida; And Others

496

Black Children, White Dreams.  

ERIC Educational Resources Information Center

Several years ago the author began visiting a number of families and children in the poor black section of Boston called Roxbury. But unlike many social scientists studying poverty in recent years, he listened--in particular to the thoughts, hopes, fears, and dreams of two fifth graders--William D. Williams and Adrien Keller. Here these two black

Cottle, Thomas J.

497

Effect of dairy powders fortification on yogurt textural and sensorial properties: a review.  

PubMed

Yogurts are important dairy products that have known a rapid market growth over the past few decades. Industrial yogurt manufacture involves different processing steps. Among them, protein fortification of the milk base is elemental. It greatly enhances yogurt nutritional and functional properties and prevents syneresis, an undesirable yogurt textural defect. Protein enrichment can be achieved by either concentration process (evaporation under vacuum and membrane processing: reverse osmosis and/or ultrafiltration) or by addition of dairy ingredients. Traditionally, skim milk powder (SMP) is used to enrich the milk base before fermentation. However, increased quality and availability of other dairy ingredients such as milk protein isolates (MPI), milk protein concentrates (MPC) whey protein isolates (WPI) and concentrates (WPC), micellar casein (MC) and caseinates have promoted their use as alternatives to SMP. Substituting different dry ingredients for skim milk powder in yogurt making affects the yogurt mix protein composition and subsequent textural and sensorial properties. This review focuses on various type of milk protein used for fortification purposes and their influence on these properties. PMID:24182425

Karam, Marie Celeste; Gaiani, Claire; Hosri, Chadi; Burgain, Jennifer; Scher, Joël

2013-11-01

498

Development of Passive Hydrogen Separation Membranes made from Co-Synthesized Nanoscale Cermet Powders  

SciTech Connect

A powder comprised of nickel oxide and proton-conducting Nd- and Zr-doped barium cerate with a particle size on the order of 10 nm has been co-synthesized using the glycine-nitrate combustion process. The two compositions are intimately mixed with no significant elemental substitution between them after synthesis. The resulting powder must be calcined at 1000 degrees C to ensure complete reaction of the cerate components. Among the barium cerate compositions investigated, the 30 per cent Zr- and 15 per cent Nd-doped material exhibited the best combination of chemical stability in CO2 and conductivity in hydrogen environments. At least 35 vol percent Ni is required to achieve percolation in the composites. When sintering is carried out in an atmosphere which promotes reduction of nickel oxide to nickel metal, the result is a mixed conducting composite which has potential use as a hydrogen separation membrane. Composites with a relative density of 98.9 per cent and submicron grains have been prepared by hot pressing.

Hardy, John S.; Thomsen, Ed C.; Canfield, Nathan L.; Crum, Jarrod V.; Weil, K. Scott; Pederson, Larry R.

2007-11-26

499

Applicability study of classical and contemporary models for effective complex permittivity of metal powders.  

PubMed

Microwave thermal processing of metal powders has recently been a topic of a substantial interest; however, experimental data on the physical properties of mixtures involving metal particles are often unavailable. In this paper, we perform a systematic analysis of classical and contemporary models of complex permittivity of mixtures and discuss the use of these models for determining effective permittivity of dielectric matrices with metal inclusions. Results from various mixture and core-shell mixture models are compared to experimental data for a titanium/stearic acid mixture and a boron nitride/graphite mixture (both obtained through the original measurements), and for a tungsten/Teflon mixture (from literature). We find that for certain experiments, the average error in determining the effective complex permittivity using Lichtenecker's, Maxwell Garnett's, Bruggeman's, Buchelnikov's, and Ignatenko's models is about 10%. This suggests that, for multiphysics computer models describing the processing of metal powder in the full temperature range, input data on effective complex permittivity obtained from direct measurement has, up to now, no substitute. PMID:24427865

Kiley, Erin M; Yakovlev, Vadim V; Ishizaki, Kotaro; Vaucher, Sebastien

2012-01-01

500

Effect of anionic substitution on the structural and magneto-electrical properties of La-Ca-Mn-O perovskite manganites  

NASA Astrophysics Data System (ADS)

The role of anion substitution of oxygen by fluorine in La0.7Ca0.3MnO3-?Fx (x=0.0 and 0.6) system has been investigated by means of X-ray powder diffraction, electrical resistivity and magnetization measurements. The oxygen content of the samples, estimated by a redox back titration method, decreases with doping while the lattice parameters and unit cell volume increase slightly. The Curie temperature and the metal-insulator transition temperatures of the samples are also found to increase with doping. The deduced magnetoresistance is slightly higher for the doped sample.

Altintas, S. P.; Mahamdioua, N.; Amira, A.; Terzioglu, C.

2014-11-01