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1

Combustion Tests of Black-Powder Substitutes for the Hand-Held Signal Flare.  

National Technical Information Service (NTIS)

Replacement of the black powder in hand-held signal flares with energetic materials of more consistent combustion properties is being studied. The black powder is currently used in both pressed and granular states to provide for the functions of ignition,...

W. F. McBratney M. S. Miller R. A. Sasse

1991-01-01

2

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2010 CFR

...The total quantity of black powder in one motor vehicle...vessel; (c) The black powder must be packed in inner metal or heavy wall conductive plastic receptacles not...must be marked “BLACK POWDER FOR SMALL ARMS” and “NA...

2010-10-01

3

Fatalities from black powder percussion handguns  

Microsoft Academic Search

Three suicides and one homicide from black powder muzzle loading handguns are reported and the muzzle velocities of two weapons are recorded. The fatal head shots caused wide wound tracts traversing the brains and intracerebral haemorrhages remote from the tract were present in every case. The skulls showed considerable fractures which were pronounced in the cases of contact shots but

B Karger; K Teige

1998-01-01

4

Substitution of Micron by Nanometer Scale Powders in Magnetorheological Fluids  

NASA Astrophysics Data System (ADS)

The effects of substitution of micron size powder by nanometer size powder in magnetorheological (MR) fluids are investigated in this study. Three MR fluid samples containing iron powder with 45% weight fraction in a carrier fluid were made by Materials Modification Inc. The difference among these three fluids is size of the magnetic particles. The first MR fluid sample contained only micron size iron powder with 10?m particle size. In the second sample, 5% micron iron was substituted with nano powders having 30~40nm mean diameter, while the third sample had 37.5% micron powder and 7.5% nano powder. Rheological tests were conducted on the three samples using a parallel disk rheometer. Highest yield stress was observed in the second MR fluid sample containing 40% micron and 5% nano iron powder. By replacing only 5% micron iron powder with nanoparticles, we achieved substantial increment in yield stress. However, when nano powder content is increased to 7.5%, the yield stress decreases and is lower than that in the all micron MR fluid. Thus, by doping a reasonable percent of nano iron powder in the MR fluid, a substantial change in the rheological characteristics is obtainable. Further investigations of effects of nano iron powder in MR fluids for higher weight fraction MR fluids will be carried out in future.

Chaudhuri, A.; Wang, G.; Wereley, N. M.; Tasovksi, Vasil; Radhakrishnan, R.

5

Here are procedures for handling persistent black-powder contamination  

Microsoft Academic Search

Recent research into black powder problems experienced by natural-gas transmission pipelines indicates steps that can be taken to control the material in gas pipelines, gathering systems, and storage facilities. Black powder (the common term for various forms of iron sulfide mixed with contaminants) is the least understood but most prominent contaminant in natural-gas pipelines and compression equipment in pipeline, refinery,

1998-01-01

6

Death by black powder revolver: a case report.  

PubMed

Deaths resulting from the use of black powder handguns are relatively uncommon compared to other firearms. We report the case of a 48 year-old woman who sustained a lethal gunshot wound to the face from a black powder revolver. Autopsy revealed extensive soot and powder deposition around the entrance wound between the right eye and nose with perforation of the skull and brain. The exit wound also contained evidence of soot. Discussion of this characteristic pattern of discharge deposition from black powder weapons is presented. PMID:20577911

Pavelites, Joseph J; Kintzele, David; Fotia, Paul; Prahlow, Joseph A

2010-12-01

7

Characteristics and wounding effects of a black powder handgun.  

PubMed

Commercial exploitation of the recent increase in interest in American history has led to an increased availability of weapons designed to use black powder (gunpowder). In some states, controls on these weapons are poor or nonexistent. In this study a .44-caliber black powder revolver is described and compared with a .45 ACP modern revolver. The kinetic energies of their missiles were very similar. In addition to the usual wound appearances determined by range and direction of fire, it was noted that the soot associated with wounds from the black powder handgun was much greater than from the control and had a characteristic sulfurous smell. Much more true tattooing was present around the black powder wounds. The spherical shape of the missile and the presence of black powder in crypts in the missile base were both characteristic of a black powder revolver. Striations were well represented on the ball but were easily destroyed during recovery because the lead was so soft. Swabs from around the wounds and from the shooter's hand revealed a large deposit of barium but little antimony. Wounds inflicted by black powder handguns may be detected more or less reliably. PMID:7264583

Labowitz, D I; Menzies, R C; Scroggie, R J

1981-04-01

8

1. LOOKING NORTH TOWARD BUILDING NO. 602, BLACK POWDER BLENDER. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. LOOKING NORTH TOWARD BUILDING NO. 602, BLACK POWDER BLENDER. POWDER TO BE BLENDED IS BROUGHT IN ON UPPER LEVEL, WHERE IT IS POURED INTO BLENDING MACHINE. BLENDED POWDER IS TRANSPORTED IN PUSH CARTS FROM LOWER LEVEL TO MAGAZINE. NOTE THAT ALL LIGHTS FOR BUILDING ARE MOUNTED OUTSIDE AND SHINE THROUGH WINDOWS. BUILDING ITSELF IS CONSTRUCTED OF WOOD. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

9

Black powder handgun deaths remain an uncommon event.  

PubMed

Although it was predicted that there would be an increase in the use of black powder guns due to their greater ease of procurement with less government control on sales, this does not seem to have been the general experience. To determine the rate of use of black powder handguns in shooting deaths in Berlin, Germany, review of the files of the Institute of Legal Medicine and Forensic Sciences, Charité-Universitätsmedizin Berlin was conducted over a 10-year period from 1997 to 2006. Out of total 85 gunshot deaths, there were only 3 where black powder handguns were used (3.5%). The cases involved 3 males aged 55, 62, and 63 years, respectively, all of whom had committed suicide with black powder percussion handguns, using 0.45, 0.56, and 0.36 caliber weapons. The source of the guns could not be determined. Wounds were characterized by excessive soot and propellant soiling and tattooing. The low number of fatalities involving black powder guns in a large forensic institution in Berlin, Germany, suggests that limiting access to such weapons would have little effect on total numbers of gunshot deaths. Simple loading mechanisms and reliability appear to be more important features influencing the choice of a handgun, rather than mere availability. PMID:19901807

Hartwig, Sven; Tsokos, Michael; Byard, Roger W

2009-12-01

10

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon black, (3-methylphenyl)-modified, substituted...Chemical Substances § 721.10149 Carbon black, (3-methylphenyl)-modified, substituted...substance identified generically as carbon black,...

2013-07-01

11

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon black, (4-methylphenyl)-modified, substituted...Chemical Substances § 721.10150 Carbon black, (4-methylphenyl)-modified, substituted...substance identified generically as carbon black,...

2013-07-01

12

2. LOOKING SOUTH TOWARD BUILDING NO. 602, BLACK POWDER BLENDER. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. LOOKING SOUTH TOWARD BUILDING NO. 602, BLACK POWDER BLENDER. ALL LIGHTING IS ON EXTERIOR OF BUILDING TO MINIMIZE EXPLOSION HAZARD. ALL METAL CONDUIT AND PIPING IS GROUNDED. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

13

Nd–Co substituted strontium hexaferrite powders with enhanced coercivity  

SciTech Connect

Graphical abstract: Display Omitted Highlights: ? Sr{sub 1?x}Nd{sub x}Fe{sub 11?x}Co{sub x}O{sub 19} was prepared by sol–gel auto-combustion method with 0 ? x ? 0.4. ? Coercivity increases 11% with 0.2 Nd–Co substitution, reaching a value of 68.9 A/m. ? The appearance of two magnetic orderings is noticed in susceptibility measurements. ? This is supported by Curie temperature and susceptibility data. -- Abstract: In this work we report the synthesis of Nd–Co substituted strontium hexaferrites of composition Sr{sub 1?x}Nd{sub x}Fe{sub 11?x}Co{sub x}O{sub 19} by the sol–gel auto-combustion method with further heat treatment. The analysis of the X-ray diffraction spectra shows the M-type hexagonal structure in samples treated at 1100 °C for 2 h. Coercivity increases 11% with 0.2 Nd–Co substitution, reaching a value of 68.9 A/m (5480 Oe) while saturation magnetization is reduced 6% to 91 A m{sup 2}/kg (91 emu/g). The behavior of magnetic susceptibility with an applied field shows two different maxima which are assigned to different magnetic orderings. This assumption is supported by the appearance of two experimental values of Curie temperatures (T{sub C}) for all the prepared samples. Magnetic susceptibility ? and T{sub C} measurements suggest an uneven distribution of the iron vacancies.

Herme, C.A. [Facultad de Ingeniería, Universidad de Buenos Aires, LAFMACEL-INTECIN, Paseo Colón 850, 1063 Buenos Aires (Argentina)] [Facultad de Ingeniería, Universidad de Buenos Aires, LAFMACEL-INTECIN, Paseo Colón 850, 1063 Buenos Aires (Argentina); Bercoff, P.G., E-mail: bercoff@famaf.unc.edu.ar [Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, IFEG, CONICET, Ciudad Universitaria, 5000 Córdoba (Argentina); Jacobo, S.E. [Facultad de Ingeniería, Universidad de Buenos Aires, LAFMACEL-INTECIN, Paseo Colón 850, 1063 Buenos Aires (Argentina)] [Facultad de Ingeniería, Universidad de Buenos Aires, LAFMACEL-INTECIN, Paseo Colón 850, 1063 Buenos Aires (Argentina)

2012-11-15

14

Sintering Behavior of Magnesium-Substituted Fluorapatite Powders Prepared by Hydrothermal Method  

PubMed Central

Magnesium-substituted fluorapatite powders were synthesized by hydrothermal method, and their sintering behavior was investigated by dilatometry in the temperature range 25–1100°C. Analysis of the obtained powders by X-ray diffraction and 31P NMR spectroscopy showed that the powders consisted of a single apatite phase and no amorphous phase has been formed. Compared to pure fluorapatite, the shrinkage of the substituted samples occurred in two steps and the temperature at which the sintering rate was maximum is lower. In addition, the shrinkage was interrupted by an expansion of the samples due to the formation of a liquid phase. The latter phase led to the crystallization of needle-crystals by a dissolution-diffusion-reprecipitation process.

Nasr, S.; Bouzouita, K.

2011-01-01

15

Sintering behavior of magnesium-substituted fluorapatite powders prepared by hydrothermal method.  

PubMed

Magnesium-substituted fluorapatite powders were synthesized by hydrothermal method, and their sintering behavior was investigated by dilatometry in the temperature range 25-1100°C. Analysis of the obtained powders by X-ray diffraction and (31)P NMR spectroscopy showed that the powders consisted of a single apatite phase and no amorphous phase has been formed. Compared to pure fluorapatite, the shrinkage of the substituted samples occurred in two steps and the temperature at which the sintering rate was maximum is lower. In addition, the shrinkage was interrupted by an expansion of the samples due to the formation of a liquid phase. The latter phase led to the crystallization of needle-crystals by a dissolution-diffusion-reprecipitation process. PMID:21577315

Nasr, S; Bouzouita, K

2011-01-01

16

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.

Shin, Myung-Gon; Lee, Gyu-Hee

2013-01-01

17

Preparation of magnesium-substituted hydroxyapatite powders by the mechanochemical–hydrothermal method  

Microsoft Academic Search

Magnesium-substituted hydroxyapatite (Mg-HAp) powders with different crystallinity levels were prepared at room temperature via a heterogeneous reaction between Mg(OH)2\\/Ca(OH)2 powders and an (NH4)2HPO4 solution using the mechanochemical–hydrothermal route. The as-prepared products contained unreacted Mg(OH)2 and therefore had to undergo purification in ammonium citrate aqueous solutions at room temperature. X-ray diffraction, infrared spectroscopy, thermogravimetric and chemical analyses were performed and it

Wojciech L. Suchanek; Kullaiah Byrappa; Pavel Shuk; Richard E. Riman; Victor F. Janas; Kevor S. TenHuisen

2004-01-01

18

Solid state NMR study of dietary fiber powders from aronia, bilberry, black currant and apple  

Microsoft Academic Search

13C CPMAS NMR spectra of dietary fiber powders from aronia (chokeberry), bilberry, black currant and apple were recorded. The spectra are complex owing to superposition of resonances from different polysaccharides and polyphenolic compounds. Standard, dipolar dephased and the T1?H partially relaxed spectra enabled the identification of several constituents: microcrystalline cellulose, pectins, lignins, cutin-like polymers and condensed tannins. The fiber powders

I. Wawer; M. Wolniak; K. Paradowska

2006-01-01

19

Synthesis of SiC Powders by Carbothermal Reduction of Enriched Brown Sepiolite with Carbon Black  

NASA Astrophysics Data System (ADS)

Ultrafine ?-silicon carbide (?-SiC) powders were successfully synthesized by carbothermal-reduction reaction (CRR) of sepiolite. Sepiolite of Turkish deposits as a silica (SiO2) precursor and carbon black as a reducing agent were mixed with constant C/SiO2 molar ratio of 4. Mixed powders were subjected to CRR at temperatures of 1450, 1500, and 1550 °C for 1 h in an atmosphere-controlled tube furnace under argon flow of 5 cm3/min. The precursor and resultant powder products were characterized by XRD, SEM, and EDX. Phase transformation was observed in powder products after CRR as a function of the reaction temperature. The results show that the cotton-like nature of sepiolite makes it an effective mineral precursor for synthesis of SiC powders, and that SiC transformation was optimized at 1550 °C with a particle size of approximately 200 nm.

Ba?ci, Cengiz; Arik, Halil

2013-04-01

20

Polyolefin backbone substitution in binders for low temperature powder injection moulding feedstocks.  

PubMed

This paper reports the substitution of polyolefin backbone binder components with low melting temperature carnauba wax for powder injection moulding applications. The effect of various binder compositions of Al?O? feedstock on thermal degradation parameters is investigated by thermogravimetric analysis. Within the experimental framework 29 original feedstock compositions were prepared and the superiority of carnauba wax over the polyethylene binder backbone was demonstrated in compositions containing polyethylene glycol as the initial opening agent and governing the proper mechanism of the degradation process. Moreover, the replacement of synthetic polymer by the natural wax contributes to an increase of environmental sustainability of modern industrial technologies. PMID:24583880

Hausnerova, Berenika; Kuritka, Ivo; Bleyan, Davit

2014-01-01

21

Organic geochemistry and petroleum potential of Pennsylvanian black shales, Powder River and Denver basins  

SciTech Connect

Thin, Middle Pennsylvanian organic-rich black shales (cumulative thickness generally less than 7 m) underlie much of the northern Denver basin and the southeastern Powder River basin. In the Powder River basin, these shales are part of the middle member of the Minnelusa Formation. During Desmoinesian time, the present-day area of the southeastern Powder River basin and the Nebraska panhandle was a shallow, at times highly saline restricted sea. In contrast, the black shales were deposited in a marine environment with normal salinity in the present-day area of northeastern Colorado, which was probably continuous with the Mid-Continent Pennsylvanian sea. Total organic carbon content of all the black shales is high (up to 20 wt. %) except along the margins of the ancient seaway and along the boundary between the open sea and the restricted basin (TOC < 2 wt. %). Extractable organic matter in the black shales is predominantly of marine origin. Evidence for marine organic material includes a predominance of low-molecular-weight alkanes (< C20) and absence of long-chain alkanes (> C25), very low saturated/aromatic hydrocarbon ratios (avg. 0.5), and relatively low pristane/phytane ratios (0.7-1.3). Although the black shales were apparently deposited in uniformly low-oxygen marine conditions, the restricted basin and open marine environments can be differentiated by organic geochemical analysis. Chloroform extracts from black shales from the restricted basin environment contain abundant red pigments, most likely derived from bacteria or algae requiring high salinity for growth. In contrast, extracts from the open marine shales, although equally organic rich, are devoid of pigments, suggesting depositional under conditions of normal seawater salinity. In bulk, organic matter in black shales from both environments is type II and has good potential for generation of liquid hydrocarbons during catagenesis.

Clayton, J.L.; Lubeck, C.M.; King, J.D.; Daws, T.A.

1987-05-01

22

Influence of the partial substitution of skim milk powder for soy extract on ice cream structure and quality  

Microsoft Academic Search

In the present work, we aimed to study the influence of the partial substitution of skim milk powder for soy extract (SE)\\u000a on the quality characteristics of ice cream. Physical and chemical composition, rheologic behavior, overrun value, hardness,\\u000a melting characteristics, and sensory properties were evaluated at levels of 0, 10, 20, and 30% substitution. The size and\\u000a distribution of the

Gustavo das Graças Pereira; Jaime Vilela de Resende; Luiz Ronaldo de Abreu; Tales Márcio de Oliveira Giarola; Italo Tuler Perrone

2011-01-01

23

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

24

Accurate characterization of pure silicon-substituted hydroxyapatite powders synthesized by a new precipitation route.  

PubMed

This paper presents a new aqueous precipitation method to prepare silicon-substituted hydroxyapatites Ca10(PO4)6-y(SiO4)y(OH)2-y(VOH)y (SiHAs) and details the characterization of powders with varying Si content up to y=1.25molmolSiHA(-1). X-ray diffraction, transmission electron microscopy, solid-state nuclear magnetic resonance and Fourier transform infrared spectroscopy were used to accurately characterize samples calcined at 400°C for 2h and 1000°C for 15h. This method allows the synthesis of monophasic SiHAs with controlled stoichiometry. The theoretical maximum limit of incorporation of Si into the hexagonal apatitic structure is y<1.5. This limit depends on the OH content in the channel, which is a function of the Si content, temperature and atmosphere of calcination. These results, particularly those from infrared spectroscopy, raise serious reservations about the phase purity of previously prepared and biologically evaluated SiHA powders, pellets and scaffolds in the literature. PMID:23518476

Marchat, David; Zymelka, Maria; Coelho, Cristina; Gremillard, Laurent; Joly-Pottuz, Lucile; Babonneau, Florence; Esnouf, Claude; Chevalier, Jérôme; Bernache-Assollant, Didier

2013-06-01

25

Structural changes induced by Sn, Zr, Al substitution in Zn k In 2O k+3 transparent conducting oxides powders as deduced by transmission electron microscopy  

Microsoft Academic Search

Sn, Zr and Al substituted ZnkIn2Ok+3 powders were made using high temperature solid state reactions. The resulting samples were first characterized by means of powder X-ray diffraction (XRD) and then by transmission electron microscopy (TEM) to identify the microstructures and phase compositions occasionally occurring within a particle. We found that the substituted powder samples are usually composed of particles made

C. Maugy; L. Dupont; N. Naghavi; C. Guery; J.-M Tarascon

2001-01-01

26

Danger assessment of a spring-gun device (muzzleloader) loaded only with black powder.  

PubMed

We report a case involving a spring-gun device (muzzleloader) loaded solely with gunpowder, installed next to shoes to prevent the neighbors' puppy from removing them. The booby trap was triggered by the 15-year-old dog-owners son when he tried to put the shoes out of the reach of the puppy. The boy suffered second degree superficial burns located mainly at the dorsal side of the right hand and fingers. To estimate the danger of the used weapon, several tests were undertaken on soap blocks from different distances and with different loads of black powder. The particle density per mm and the depth of black powder tattooing in the soap was compared with the boy's injuries, and found conclusive with the gun-owners statement regarding the loading of the weapon. Furthermore, our experiments indicated that the gunpowder load involved was not able to inflict permanent damage, not even to the eyes, at the here estimated firing distance. PMID:20010291

Voisard, Matthias X; Kneubuehl, Beat P

2010-03-01

27

Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.  

PubMed

The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions. PMID:22663136

Clack, Herek L

2012-07-01

28

(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

29

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...Chemical Substances § 721.10149 Carbon black, (3-methylphenyl)-modified...substance identified generically as carbon black,...

2010-07-01

30

Magnetic comparison of BaCa and BaSr substituted hexaferrite powders  

NASA Astrophysics Data System (ADS)

Results on magnetic studies of Ba0.5Sr0.5Fe12-2x(ZnTi)xO19 and Ba0.75Ca0.25Fe12-2x(ZnTi)xO19, where x = 0.2 to 0.6, ferromagnetic powders prepared by mechanical alloying are discussed. The structural and magnetic properties of the resulting powders were analyzed by thermo-magnetic analysis, X-ray diffraction, scanning electron microscopy, Mössbauer spectroscopy and magnetic measurements. Curie temperature, Tc decreased dramatically (drop ~ 39%) for BaCa samples, whilst for BaSr samples remained almost without change (diminution ~ 2%) at x <= 0.2. SEM studies showed that all the particles present nearly hexagonal platelet shape.

González-Angeles, A.; Lipka, J.; Grusková, A.; Sláma, J.; Jan?árik, V.; Sluge?, V.

2010-03-01

31

Production of strontium-substituted lanthanum manganite perovskite powder by the amorphous citrate process  

Microsoft Academic Search

The amorphous citrate process has been used to produce Mn2O3, Mn3O4, LaMnO3, SrMnO3 and strontium-substituted LaMnO3. The citrate-nitrate gels were dehydrated at 70‡ C to yield solid precursor materials. The decomposition\\/oxidation of the precursors have been studied using thermogravimetry and evolved gas analysis. The products of decomposition have been characterized by X-ray diffraction analysis, scanning electron microscopy and, in the

M. S. G. Baythoun; F. R. Sale

1982-01-01

32

Paleoenvironmental and source rock assessment of black shales of Pennsylvanian Age, Powder River and northern Denver basins  

SciTech Connect

Thin Middle Pennsylvanian (Desmoinesian) organic-rich black shales (cumulative thickness < 50 ft) underlie much of the northern Denver basin and southeastern Powder River basin. In the Powder River basin, these shales are part of the middle member of the Minnelusa Formation. During Desmoinesian time, the present area of the southeastern Powder River basin and Nebraska was a shallow, at times highly saline, restricted sea. In contrast, in the present area of northeastern Colorado, black shales were deposited in a marine environment with normal salinity that was probably continuous with the Mid-Continent Pennsylvanian sea. Assessment of the paleoenvironment has been carried out using organic geochemical parameters. Shales deposited in the restricted basin setting contain abundant porphyrins (25,000-30,000 ppm relative to total extractable organic matter) and significant quantities of aryl isoprenoids. The aryl isoprenoid compounds (1) are evidence for the presence of the sulfur bacteria families Chlorobiaceae and possibly Chromatiaceae and (2) indicate that euxinic conditions existed in the water column. High ratios of sulfur to carbon in the shales support this interpretation. In contrast, extracts from black shale in the normal sea to the south contain lower porphyrin concentrations (generally less than 1000 ppm) and aryl isoprenoids are minor constituents or are absent. Sulfur/carbon ratios in these latter shales are similar to those observed for normal marine shales (that is, not euxinic conditions). Other paleoenvironmental indicators (sterane composition, alkane distribution) are consistent with these observations. Bulk organic matter in the black shales from both environments is type II and has good source potential for generation of liquid hydrocarbons during catagenesis. Pyrolysis yields of 50 kg/MT (50,000 ppm) are common, and in some shales, yield is 100 kg/MT (100,000 ppm).

Clayton, J.L.; King, J.D.; Lubeck, C.M.; Leventhal, J.S.; Daws, T.A.

1988-07-01

33

Grain coupling and critical current density in Fe-sheathed carbon-substituted MgB2 tapes fabricated through an ex situ process using chemically treated powder  

NASA Astrophysics Data System (ADS)

We have studied grain coupling and critical current density (Jc) in ex situ processed Fe-sheathed MgB2-xCx (x = 0, 0.05 and 0.10) tapes fabricated by a powder-in-tube (PIT) technique. Compared with commercially available MgB2 powder, homemade powders of MgB2-xCx contained larger amounts of MgO. Therefore, tapes using these homemade powders showed much lower Jc values. Chemical treatment of the homemade powders in acid solutions brought about a large enhancement in Jc of tapes, mainly due to the dissolution of MgO. The transport Jc values of tapes were almost the same at 4.2 K and 10 T for both powders with chemical treatment, independent of x, although tapes using powders with x>=0.05 showed a large enhancement in normalized volume pinning force (Fp) in the high-field region and small field dependence in Jc due to carbon substitution. This can be attributed to high temperature heat treatment for ex situ processed MgB2 tapes. At sintering, MgB2-xCx probably partially decomposes into MgB2, MgB4 and C, producing precipitates at grain boundaries. This brings about weak coupling of grains and hence negligible enhancement in the low-field region in Jc of tapes with x>=0.05.

Fujii, H.; Togano, K.; Ozawa, K.

2008-09-01

34

Thermal maturation and oil generation history of Pennsylvanian (Desmoinesian) black shales of Powder River and northern Denver basins  

SciTech Connect

Thin Middle Pennsylvanian (Desmoinesian) organic-rich black shales (cumulative thickness < 50 ft) underlie much of the northern Denver basin and southeastern Powder River basin. In the Powder River basin, these shales are part of the middle member of the Minnelusa Formation. During Desmoinesian time, the present area of the southeastern Powder River basin and Nebraska panhandle was a shallow, at times highly saline, restricted sea. In contrast, in the present area of northeastern Colorado, these black shales were deposited in a sea with normal marine salinity. The authors have evaluated the thermal maturity of the shales using a combination of petrographic and geochemical techniques. In general, thermal maturities are fairly low (mostly equivalent to R{sub 0} about 0.6% or less), although an area of higher heat flow and attendant higher thermal maturity is evident in the southern Nebraska Panhandle area. The authors determined kinetic parameters for oil generation from the shales at several locations in the study area. The activation energy (E{sub a}) distribution for thermal decomposition of kerogen in these shales is highly variable (about 10 kcal/mole range for the average E{sub a}) and can be related to the paleogeography (i.e., the chemical conditions during deposition). An inverse relationship exists between the average E{sub a} for the kerogen breakdown and sulfur content of the shales. The result of this difference in E{sub a} values is that oil generation histories of the shales would be significantly different for a given thermal history even though the organic matter is fairly uniform type II in bulk analysis.

Clayton, J.L.; Daws, T.A. (Geological Survey, Denver, CO (USA))

1989-09-01

35

Genotoxic effects of three selected black toner powders and their dimethyl sulfoxide extracts in cultured human epithelial A549 lung cells in vitro.  

PubMed

Until now, the adverse effects of toner powders on humans have been considered to be minimal. However, several recent reports have suggested possible significant adverse health effects from toner dust inhalation. The aim of this study was to evaluate the genotoxic potential of black toner powders in vitro. For the study of DNA damage, A549 cells were exposed to toner-powder suspensions and to their DMSO extracts, and then subjected to the comet assay and to the in-vitro cytokinesis block micronucleus test (CB-MNvit). Cytotoxic effects of the toner samples were assessed by the erythrosin B assay. Furthermore, size, shape, and composition of the toner powders were investigated. None of the three toner powders or their DMSO extracts reduced cell viability; however, they did induce DNA damage and formed micronuclei at concentrations from 80 to 400 ?g cm(-2) , although to a varying extent. All toner powders contain considerable amounts of the pigments carbon black and magnetite (Fe(3) O(4) ) as well as small amounts of polycyclic aromatic hydrocarbons (PAHs). The overall results of our in-vitro study suggest that the investigated toner-powder samples are not cytotoxic but genotoxic. From the results of the physical and chemical characterization, we conclude that metals and metalloids as components of magnetite, or PAHs as components of the carbon-bearing material, are responsible for the genotoxic effects. Further research is necessary to determine the relevance of these in-vitro observations for private and occupational toner powder exposure. PMID:20872829

Gminski, Richard; Decker, Katharina; Heinz, Christina; Seidel, Albrecht; Könczöl, Mathias; Goldenberg, Ella; Grobéty, Bernard; Ebner, Winfried; Gieré, Reto; Mersch-Sundermann, Volker

2011-05-01

36

Platinum black powder as a heat exchanger material at low temperatures  

NASA Astrophysics Data System (ADS)

A procedure has been developed for producing a thin layer of sintered platinum powder with a very large surface area, a relatively low electrical resistivity, and a reasonably small void volume. This layer has been bonded to a copper sample cell and used to cool solid 3He to 0.7 mK.

Roach, P. R.; Takano, Y.; Hilleke, R. O.; Vrtis, M. L.; Jin, D.; Sarma, B. K.

37

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

38

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

SciTech Connect

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 [Orissa Engineering College, Bhubaneswar (India); Sahoo, G. [Tapaswini Ayurvedic clinic and Research center, Balasore (India); Das, K. [Gopobandhu Ayurvedic Medical College, Puri (India); Ghosh, Sudipto; Panigrahi, S. C. [Department of Metallurgical and Materials Engineering, IIT, Kharagpur (India)

2008-10-23

39

Black market exchange rate, currency substitution and the demand for money in LDCs  

Microsoft Academic Search

Mundell's conjecture in 1963 that the demand for money could depend on the exchange rate in addition to income and interest rate has received some attention in the literature by including the official exchange rate and estimating the money demand in a few developed countries. In less developed countries, since there is a black market for foreign exchange, it has

Mohsen Bahmani-Oskooee; Altin Tanku

2006-01-01

40

Influence of setting liquid composition and liquid-to-powder ratio on properties of a Mg-substituted calcium phosphate cement.  

PubMed

The influence of four variables on various properties of a Mg-substituted calcium phosphate cement (CPC) was investigated. The variables were the heat treatment temperature of the precipitated powders, the composition of the setting liquid, the liquid-to-powder ratio (LPR), and the time over which hardened specimens were cured in air. The properties analysed were the phase composition of the starting powder, the initial setting time, the evolution of the storage shear modulus (G') and the loss shear modulus (G'') with the cement paste curing time (t), and the compressive strength. The presence of alpha-TCP in CPC facilitated the setting and hardening properties due to its progressive dissolution and the formation of brushite crystals. As far as the liquid composition is concerned, in cases where citric acid was used, adding a rheology modifier (10 wt.% polyethylene glycol or 0.5 wt.% hydroxyl propylmethylcellulose) to the acid led to an increase in the initial setting time, while an increase in the acid concentration led to a decrease in the initial setting time. The initial setting time showed to be very sensitive towards the LPR. The evolution of G' and G'' with curing time reflected the internal structural changes of cement pastes during the setting process. The compressive strength of the wet-hardened cement specimens with and without Mg increased with curing time increasing, being slightly higher in the case of Mg-substituted CPC. The results suggest that Mg-substituted CPC holds a promise for uses in orthopaedic and trauma surgery such as for filling bone defects. PMID:19121609

Pina, S; Olhero, S M; Gheduzzi, S; Miles, A W; Ferreira, J M F

2009-05-01

41

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

2014-07-23

42

Performance Study of compact wood powder material processing for improved impact characteristics aiming at substitute for plastics  

Microsoft Academic Search

Recently, a plastic-like material has been obtained by compression of wood powder only under an appropriate temperature and pressure conditions. It is considered that this change in a surface texture like transformation comes from auto-condensation of wood components. The static bending strength of the wood powder material (WPM) at 23°C is roughly the same as that of plastics such as

T. Miki; K. Takeuchi; H. Sugimoto; K. Kanayama

2007-01-01

43

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

Code of Federal Regulations, 2011 CFR

...substituted] phenyl- modified, sodium salts (generic). 721.10075 Section 721...substituted] phenyl- modified, sodium salts (generic). (a) Chemical substance...substituted] phenyl-modified, sodium salts (PMN P-05-722) is subject to...

2011-07-01

44

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

Code of Federal Regulations, 2012 CFR

...substituted] phenyl- modified, sodium salts (generic). 721.10075 Section 721...substituted] phenyl- modified, sodium salts (generic). (a) Chemical substance...substituted] phenyl-modified, sodium salts (PMN P-05-722) is subject to...

2012-07-01

45

The measurement of thermal conductivities of silica and carbon black powders at different pressures by thermal conductivity probe  

Microsoft Academic Search

This investigation was done to study the gas filled powder insulation and thermal conductivity probe for the measurement of thermal conductivity of powders. The mathematical analysis showed that the heat capacity of the probe itself and the thermal resistance between the probe and powder must be considered. The authors developed a slender probe and measured the effective thermal conductivity of

X. G. Liang; X. S. Ge; Y. P. Chang; G. Liu; D. P. Wu

1992-01-01

46

Defect structure in aliovalently-doped and isovalently-substituted PbTiO3 nano-powders.  

PubMed

The defect structure of Fe(3+)-, Cu(2+)-, Mn(4+)- and Gd(3+)-doped PbTiO(3) nano-powders has been studied by electron paramagnetic resonance (EPR) spectroscopy. Analogous to the situation for 'bulk' ferroelectrics, Fe(3+) and Cu(2+) act as acceptor-type functional centers that form defect complexes with charge-compensating oxygen vacancies. The corresponding defect dipoles are aligned along the direction of spontaneous polarization, P(S), and possess an additional defect polarization, P(D). Upon the transition to the nano-regime, the defect structure is modified such that orientations perpendicular to P(S), [Formula: see text] and [Formula: see text] also become realized. Moreover, the binding energy for the defect complexes is lowered such that instead 'free' Fe'(Ti) and V··(O)-centers are formed. As a consequence, the concentration of mobile V··(O) that enhances the ionic conductivity through drift diffusion is increased for the nano-powders. Finally, in the nano-regime the ferroelectric 'hardening' is expected to be considerably decreased as compared to the 'bulk' compounds. In contrast to the acceptor-type dopants, the donor-type Gd(3+) dopant is incorporated as an 'isolated' functional center, where charge compensation by means of lead vacancies is performed in distant coordination spheres. PMID:21403264

Erdem, Emre; Jakes, Peter; Parashar, S K S; Kiraz, Kamil; Somer, Mehmet; Rüdiger, Andreas; Eichel, Rüdiger-A

2010-09-01

47

N vacancy, substitutional O, and Al defects in the bandgap of composition-tunable nonstoichiometric AlN powder  

NASA Astrophysics Data System (ADS)

AlN powders are prepared by direct nitridation via Al liquid and vapor phases in mixed atmospheres of N2 and NH3 with different NH3/N2 ratios. The reaction analysis reveals that NH3 acts as catalyst for N2 dissociation and the transportations of N, O, and Al in the liquid phase are different from those in the vapor phase. Accordingly, the products are Al-rich and composition-tunable nonstoichiometric AlN in which N, O, and Al content values change with nitridation atmosphere and temperature, leading to the variation of the relevant defect concentration. Therefore, the AlN powders exhibit prominent absorption bands around 5.30, 3.40, and 1.50 eV, which are tentatively assigned to VN, ON donors, and AlN acceptor respectively. Furthermore, a new donor named [VN—ON] complex is predicted at 4.40 eV within the 5.90 eV bandgap. It is demonstrated that the optical spectra of nonstoichiometric AlN are preferable to the nominal stoichimometric one for the identification of the defects energy level.

Zhang, Dian; Liu, Fa-Min; Cai, Lu-Gang

2014-06-01

48

The measurement of thermal conductivities of silica and carbon black powders at different pressures by thermal conductivity probe  

Microsoft Academic Search

This investigation was done to study the gas filled powder insulation and thermal conductivity probe for the measurement of\\u000a thermal conductivity of powders. The mathematical analysis showed that the heat capacity of the probe itself and the thermal\\u000a resistance between the probe and powder must be considered. The authors developed a slender probe and measured the effective\\u000a thermal conductivity of

X. G. Liang; X. S. Ge; Y. P. Chang; G. Liu; D. P. Wu

1992-01-01

49

The effect of La-substitution on magnetic properties of nanosized Sr 1- xLa xTi 0.05Zn 0.2(Fe 3+) 11.75- ?(Fe 2+) ?O 19 powders  

NASA Astrophysics Data System (ADS)

A series of La-substituted M-type Sr hexaferrite powders Sr 1- xLa xTi 0.05Zn 0.2Fe 3+11.75O 19, wherein x ranges from 0.1 to 0.5 with a step of 0.1, have been prepared by the conventional ceramic method and were then milled in a high energy mill to prepare nanosized powders. XRD investigation of the calcined and the milled powders shows that single phase hexaferrite structure has been formed after calcining and has not changed after milling. The lattice parameters and the mean crystallite sizes of the samples have been determined from the XRD data and Scherrer's formula. The results show that the lattice parameters ("?" and "c") decrease with increase in La-substitution and the mean crystallite size of the milled powders is about 17 nm. Coercivities and magnetizations of the samples in a magnetic field of 16 kOe have been determined from the room temperature hysteresis loops. It was found that both parameters increase with La substitutions up to 0.3 and then decrease for higher substitutions. These variations were attributed to the enhancement of hyperfine field and spin-canting magnetic structure when La content increases. In addition, the magnetizations were smaller for the nanosized samples in comparison with those of bulk ones, which were discussed according to the core-shell model. Also the results show that annealing of the nanosized samples up to 500 °C can enhance coercivity and magnetization of the samples, which is discussed based on crystallite size growth.

Amighian, J.; Mozaffari, M.; Arab, A.; Yousefi, M. H.

2010-03-01

50

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

51

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.

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

2014-01-01

52

Use of Cement Copper in an Iron-Copper-Carbon Powder Metallurgy Alloy.  

National Technical Information Service (NTIS)

An investigation was made of the substitution of cement copper powder for commercial copper powder in an Fe-7 pct Cu-1 pct C powder metallurgy alloy. Copper powders from six different commercial cementation operations were separately upgraded by screening...

R. L. Crosby D. H. Desy R. M. Doerr

1970-01-01

53

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

54

Effect of Cr substitution on the crystal and magnetic structure of (Pr{sub 0.55}Ca{sub 0.45})MnO{sub 3}: A neutron powder diffraction investigation  

SciTech Connect

The crystal and magnetic structures of (Pr{sub 0.55}Ca{sub 0.45})(Mn{sub 1-y}Cr{sub y})O{sub 3} (y=0.00,0.03,0.06) have been investigated between 5 and 300 K by neutron powder diffraction and dc magnetic measurements. An orthorhombic-to-monoclinic phase transition occurs on cooling in (Pr{sub 0.55}Ca{sub 0.45})MnO{sub 3} at T{approx_equal}239 K; at lower temperature charge ordering in the Mn sublattice, coupled with orbital ordering, induces an AFM spin ordering within the monoclinic phase. Cr substitution at the Mn site hinders the structural phase transition, although for the y=0.03 sample small amounts of the monoclinic phase coexist at low temperature with the main phase characterized by an orthorhombic structure. Cr substitution prevents charge ordering, favoring double exchange and hence FM spin ordering within the Mn sublattice.

Martinelli, A.; Tropeano, M. [INFM-LAMIA-CNR, C.so Perrone 24, 16152 Genova (Italy); Ferretti, M. [INFM-LAMIA-CNR, C.so Perrone 24, 16152 Genova (Italy); Dipartimento di Chimica e Chimica Industriale, Universita di Genova, Via Dodecaneso 31, 16146 Genova (Italy); Castellano, C. [Dipartimento di Fisica, Universita di Roma 'La Sapienza', P. le A. Moro 2, 00185 Rome (Italy); Mondelli, C. [CNR-INFM and CRS Soft, Institut Laue-Langevin, 6 rue Jules Horowitz, 38042 Genoble Cedex 9 (France); Cimberle, M. R. [CNR-IMEM sezione di Genova c/o Dipartimento di Fisica, Universita di Genova, Via Dodecaneso 33, 16146, Genova (Italy); Ritter, C. [Institute Laue-Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)

2006-02-01

55

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.

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

56

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

57

Metal Powders (Metall Pulver).  

National Technical Information Service (NTIS)

This book discusses metal powders for powder metallurgy, specific topics include Electrolytic copper powder, Copper alloy powders, Lead powders, tin powders, Partially prealloyed powders, Premixes, Mixed powders to customers' specifications, Quality contr...

1986-01-01

58

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

59

Cation substitution in synthetic meridianiite (MgSO4·11H2O) II: variation in unit-cell parameters determined from X-ray powder diffraction data  

NASA Astrophysics Data System (ADS)

We have prepared aqueous MgSO4 solutions doped with various divalent metal cations (Ni2+, Zn2+, Mn2+, Cu2+, Fe2+, and Co2+) 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. In a companion paper (Fortes et al., in Phys Chem Min 39) we reported the identification of various phases using X-ray powder diffraction, including meridianiite-structured undecahydrates, melanterite- and epsomite-structured heptahydrates, novel enneahydrates and a new octahydrate. In this work we report the changes in unit-cell parameters of these crystalline products where they exist over sufficient dopant concentrations. We find that there is a linear relationship between the rate of change in unit-cell volume as a function of dopant concentration and the ionic radius of the dopant cation; large ions such as Mn2+ produce a substantial inflation of the hydrates' unit-cell volume, whereas smaller ions such as Ni2+ produce a modest reduction in unit-cell volume. Indeed, when the data for all hydrates are normalised (i.e., divided by the number of formula units per unit-cell, Z, and the hydration number, n), we find a quantitatively similar relationship for different values of n. Conversely, there is no relationship between the degree of unit-cell inflation or deflation and the limit to which a given cation will substitute into a certain hydrate structure; for example, Co2+ and Zn2+ affect the unit-cell volume of MgSO4·11H2O to a very similar degree, yet the solubility limits inferred in our companion paper are >60 mol. % Co2+ and <30 mol. % Zn2+.

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

2012-06-01

60

Magnetic properties of substituted barium ferrite powders  

SciTech Connect

Hexagonal barium ferrites were prepared using the citrate method. Cobalt and titanium were added in the amounts x from 0.2 to 1.1 ion/f.u. related to the formula BaCo{sub x}Ti{sub x}Fe{sub 12{minus}2x}O{sub 19}. The heat treatment has been applied in three steps of 550 C/5 hrs, 850 C/2 hrs and 1,100 C/2 hrs. The following magnetic properties have been achieved: H{sub c} {approximately} 80 kA/m, J{sub s} {approximately} 120 {times} 10{sup {minus}6} Tkg{sup {minus}1} m{sup 3}, and J{sub r} {approximately} 60 {times} 10{sup {minus}6} Tkg{sup {minus}1} m{sup 3} in the composition for which x is equal to 0.5 ion/f.u. The magnetic parameters have been measured by the vibration magnetometer.

Gruskova, A. [Slovak Univ. of Technology, Bratislava (Slovakia). Dept. of Electrotechnology] [Slovak Univ. of Technology, Bratislava (Slovakia). Dept. of Electrotechnology

1994-03-01

61

Revealing the powdering methods of black makeup in Ancient Egypt by fitting microstructure based Fourier coefficients to the whole x-ray diffraction profiles of galena  

NASA Astrophysics Data System (ADS)

Galena (PbS) is a major ingredient in ancient Egyptian eye makeup. The microstructure of PbS in Egyptian cosmetic powders is used as a fingerprint and is matched with the microstructures produced artificially in geological galena minerals. The microstructure of PbS is determined by x-ray diffraction peak profile analysis in terms of dislocation density, crystallite size, and size distribution. High-resolution powder diffractograms were measured at the ESRF Grenoble synchrotron source with high resolution and high peak-to-background ratios. The Fourier coefficients of the first nine measured reflections of galena are fitted using physically based Fourier coefficients of strain and size functions. Strain anisotropy is accounted for by the dislocation model of the mean square strain. The x-ray data are supplemented by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs, and are compared with archæological documents. It enables us to describe the procedures of eye makeup manufacturing in the Middle and New Kingdoms of Egypt some 2000 years before Christ.

Ungár, T.; Martinetto, P.; Ribárik, G.; Dooryhée, E.; Walter, Ph.; Anne, M.

2002-02-01

62

Neutron-powder-diffraction study of the nuclear and magnetic structures of the substitution compound (Y1- xCax)Ba2Fe3O8+? (x=0.05, 0.10, and 0.20)  

NASA Astrophysics Data System (ADS)

The nuclear and magnetic structures of (Y1- xCax)Ba2Fe3O8+? with x=0.05, 0.10, and 0.20 have been investigated by neutron-powder diffraction at room temperature. The compound crystallizes with the symmetry of space group P4/mmm and has a structure similar to that of the superconductor YBa2Cu3O7 (1:2:3). There are two types of Fe atoms in the unit cell, one having fivefold pyramidal coordination and the other octahedral coordination. The Ca and Y atoms are randomly distributed over the 1/2,1/2,1/2 position, which are exclusively occupied by Y in the 1:2:3 superconductor. Since the oxygen sites on the basal plane of the structure are fully occupied to achieve octahedral coordination for the iron atoms on this plane, the oxygen content is eight atoms per formula unit, the barium atoms are twelvefold coordinated, and the coordination polyhedron is a cuboctahedron. Extra oxygen atoms corresponding to ?=0.08 and 0.05 are located in the Y/Ca layer. The presence of these atoms produces disorder in the structure resulting in a shift of the oxygen atoms located near the plane of the pyramidal iron atoms. The charge compensation required by the substitution of Y3+ by Ca2+ is achieved in these materials by elimination of the extra oxygen, rather than oxidation of the iron atoms. The magnetic structure is based on a unit cell related to that of the nuclear structure by the transformation of axes (1,-1,0/1,1,0/0,0,2). The magnetic origin of some of the observed diffraction peaks was established by polarized neutron diffraction measurements. As in YBa2Fe3O8, the iron moments are coupled antiferromagnetically within each (FeO2) layer as well as along the c axis of the structure, and they lie in the planes perpendicular to c. The magnetic moments of the two iron atoms are practically identical and have values at room temperature of =3.50(3)?B, 3.52(2)?B, and 3.62(2)?B for the three compositions x=0.05, 0.10, and 0.20, respectively.

Sora, I. Natali; Huang, Q.; Lynn, J. W.; Rosov, N.; Karen, P.; Kjekshus, A.; Karen, V. L.; Mighell, A. D.; Santoro, A.

1994-02-01

63

Blood Substitutes.  

National Technical Information Service (NTIS)

The functional characteristics of heme proteins can be modified to produce hemoglobins that can be used as blood substitutes in different therapeutic applications. Stable polymers of tetrameric hemoglobin, and of myoglobin molecules, are provided for use ...

C. Fronticelli W. S. Brinigar

2004-01-01

64

Aspirin Substitutes.  

National Technical Information Service (NTIS)

The research investigates the toxicity of the aspirin substitutes acetaminophen, phenacetin, and salicylamide. Fatalities, particularly in children, occur at relatively low doses of acetaminophen, due principally to hepatic necrosis, and also at relativel...

D. Neff J. T. Maddock K. Druck

1977-01-01

65

Powder diffraction.  

National Technical Information Service (NTIS)

the importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquito...

M. Hart

1995-01-01

66

Powder diffraction  

Microsoft Academic Search

The powder diffraction method, by using conventional X-ray sources, was devised independently in 1916 by Debye and Scherrer in Germany and in 1917 by Hull in the United States. The technique developed steadily and, half a century later, the `traditional' applications, such as phase identification, the determination of accurate unit-cell dimensions and the analysis of structural imperfections, were well established.

J. Ian Langford; Daniel Louër

1996-01-01

67

Powder diffraction  

SciTech Connect

the importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940`s, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments.

Hart, M.

1995-12-31

68

The Black Body Function.  

ERIC Educational Resources Information Center

Discusses using black body function for radiative heat transfer, which can be used in a real-life application in a number of different topics in A-level and first-year undergraduate mathematical methods courses such as differentiation, solving nonlinear equations, and integration by substitution. (ASK)

Lawson, D. A.

1998-01-01

69

Sammutteiden Identifiointi Osa 1. Sammutejauheet (Identification of Fire Extinguishing Media. Part 1. Extinguishing Powders).  

National Technical Information Service (NTIS)

When accepting portable fire extinguishers for commercial use, the responsible authority also specifies the trade name of the extinguishing powder used in the extinguisher. In cases where it is suspected that the extinguishing powder has been substituted,...

T. Andsten H. Weckman

1997-01-01

70

X-ray powder diffraction, vibration and thermal studies of [A{sub 0.92}(NH{sub 4}){sub 0.08}]{sub 2}TeCl{sub 4}Br{sub 2} with A = Cs, Rb: Influence of mixed cationic and anionic substitutions  

SciTech Connect

Graphical abstract: The structures of [A{sub 0.92}(NH{sub 4}){sub 0.08}]{sub 2}TeCl{sub 4}Br{sub 2} with A = Cs, Rb belong to the tetragonal {beta}-K{sub 2}SnCl{sub 6} structure type. Highlights: Black-Right-Pointing-Pointer The two new compound crystallises in P4/mnc tetragonal space group. Black-Right-Pointing-Pointer The structure is considered as isolated octahedred TeCl{sub 4}Br{sup 2-}. Black-Right-Pointing-Pointer The octahedra connected by ionic and hydrogen bonding through the Cs/Rb or N atoms. Black-Right-Pointing-Pointer A DTA/TGA experiment reveals one endothermic peak at 780 K for these compounds. Black-Right-Pointing-Pointer One endothermic peak is detected at around 213 K by DSC experiment. -- Abstract: The crystal structures of [A{sub 0.92}(NH{sub 4}){sub 0.08}]{sub 2}TeCl{sub 4}Br{sub 2} with A = Cs, Rb have been determined using X-ray powder diffraction techniques. The two compounds crystallize in the tetragonal space group P4/mnc, with the unit cell parameters: a = 7.452(1) Angstrom-Sign , c = 10.544(3) Angstrom-Sign , Z = 2 and a = 7.315(2) Angstrom-Sign , c = 10.354(4) Angstrom-Sign , Z = 2 in the presence of Cs and Rb, respectively. These two compounds have an antifluorite-type arrangement of NH{sub 4}{sup +}/Rb{sup +}/Cs{sup +} and octahedral TeCl{sub 4}Br{sub 2}{sup 2-} anions. The stability of these structure is by ionic and hydrogen bonding contacts: A Midline-Horizontal-Ellipsis Cl, A Midline-Horizontal-Ellipsis Br and N-H Midline-Horizontal-Ellipsis Cl, N-H Midline-Horizontal-Ellipsis Br. The different vibrational modes of these powders were analysed by FTIR and Raman spectroscopic studies. A DTA/TGA experiment reveals one endothermic peak at 780 K implicating the decomposition of the sample. At low temperature, one endothermic peak in thermal behavior is detected at around 213 K by DSC experiment. This transition was confirmed by dielectric measurements.

Aribia, W. Ben; Abdelmouleh, M. [Laboratoire des Sciences des Materiaux et de l'environnement, Universite de Sfax, Faculte des Sciences de Sfax, 3018 (Tunisia)] [Laboratoire des Sciences des Materiaux et de l'environnement, Universite de Sfax, Faculte des Sciences de Sfax, 3018 (Tunisia); Kabadou, A., E-mail: kabadouahlem@yahoo.fr [Laboratoire des Sciences des Materiaux et de l'environnement, Universite de Sfax, Faculte des Sciences de Sfax, 3018 (Tunisia); Van Der Lee, A. [Institut Europeen des Membranes (UMR 5635), Universite de Montpellier II, cc 047, Place E. Montpellier (France)] [Institut Europeen des Membranes (UMR 5635), Universite de Montpellier II, cc 047, Place E. Montpellier (France)

2012-05-15

71

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

72

Location and oxidation state of iron in Fe-substituted CuInS{sub 2} chalcopyrites  

SciTech Connect

CuIn{sub 1-x}Fe{sub x}S{sub 2}(x=0-0.30) was synthesized via high-temperature, solid-state synthesis. Phase-pure materials were found in samples where x=0-0.15, after which a secondary phase became apparent. The materials were characterized with the use of X-ray powder diffraction (XRPD), and Reitveld refinement revealed a linear decrease in unit cell volume as the amount of iron substitution increases in accordance with Vegard's Law. Inductively coupled plasma (ICP) confirms that the actual stoichiometry is close to the nominal composition of the materials. The temperature for both the chalcopyrite-to-sphalerite and the sphalerite-to-wurtzite phase transitions decreases with increasing iron substitution for indium. These findings suggest that the Fe is being randomly incorporated into the crystal structure of the CuInS{sub 2}. X-ray photoelectron spectroscopy (XPS) measurements were used to determine the oxidation state of the ions (Cu{sup 1+}, In{sup 3+,} and S{sup 2-}), and Fe{sup 57} Moessbauer spectroscopy verified that the iron is in the 3{sup +} oxidation state. Band gaps of the solid solution were estimated to be in the range of 0.70-0.85 eV. Rietveld refinement of neutron diffraction data indicates that the iron is occupying the In site within the chalcopyrite structure. - Graphical abstract: CuIn{sub 1-x}Fe{sub x}S{sub 2} samples were prepared by solid-state synthesis. X-ray photoelectron spectroscopy and Moessbauer spectroscopy indicate Cu{sup +}, In{sup 3+}, Fe{sup 3+} and S{sup 2-} in the samples. Rietveld refinement of neutron powder diffraction data shows Fe{sup 3+} residing on the indium site. The band gaps of the iron-containing samples decrease to {approx}0.7 eV. Highlights: Black-Right-Pointing-Pointer X-ray photoelectron spectroscopy confirms the presence of Cu{sup +}, In{sup 3+} and S{sup 2-}. Black-Right-Pointing-Pointer Moessbauer spectroscopy indicates the presence of Fe{sup 3+}. Black-Right-Pointing-Pointer Rietveld refinement of neutron powder diffraction data shows iron on the indium site. Black-Right-Pointing-Pointer The band gap decreases to {approx}0.7 eV with only 5% iron substitution. Black-Right-Pointing-Pointer Additional characterization is reported.

Burnett, Johanna D. [Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282 (United States); Xu Tianhong; Sorescu, Monica [Department of Physics, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282 (United States); Strohmeier, Brian R. [RJ Lee Group, Inc., 350 Hochberg Rd., Monroeville, PA 15146 (United States); Thermo Fisher Scientific, 5225 Verona Road, Madison, WI 53711 (United States); Sturgeon, Jacqueline [RJ Lee Group, Inc., 350 Hochberg Rd., Monroeville, PA 15146 (United States); Gourdon, Olivier [Chemical and Engineering Materials Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Baroudi, Kristen; Yao Jinlei [Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282 (United States); Aitken, Jennifer A., E-mail: aitkenj@duq.edu [Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282 (United States)

2013-01-15

73

Ceramic Powders  

NASA Technical Reports Server (NTRS)

In developing its product line of specialty ceramic powders and related products for government and industrial customers, including companies in the oil, automotive, electronics and nuclear industries, Advanced Refractory Technologies sought technical assistance from NERAC, Inc. in specific areas of ceramic materials and silicon technology, and for assistance in identifying possible applications of these materials in government programs and in the automotive and electronics industry. NERAC conducted a computerized search of several data bases and provided extensive information in the subject areas requested. NERAC's assistance resulted in transfer of technologies that helped ART staff develop a unique method for manufacture of ceramic materials to precise customer specifications.

1984-01-01

74

Sintering behavior and thermal stability of Na +, SiO 4 4? and CO 3 2? co-substituted hydroxyapatites  

Microsoft Academic Search

Sinterability and thermal stability of nanocrystalline hydroxyapatite powders with co-substituted sodium, silicate and carbonate ions have been investigated. The effect of powder characteristics on the thermal stability and physico-chemical properties of the produced ceramic bodies have been correlated. Thermal stability of hydroxyapatite depends on the amounts and nature of different substitutents. Substitution, of both sodium and carbonate ions, in hydroxyapatite

Nasser Y. Mostafa; H. M. Hassan; F. H. Mohamed

2009-01-01

75

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

76

Effect of Black Pow d er contaminants on Gas metering equipment  

Microsoft Academic Search

Black powder is usually found in natural gas transmission and distribution systems throughout the world. The Hellenic gas transmission system was constantly subjected to large volumes of black powder, mainly pipeline corrosion product, originated upstream and carried in the gas flow. Due to amorphous nature of this powder, particles was breaking up to sub-micron sizes, flowed through filtration devices, agglomerated

Nikolaos A. Tsochatzidis

77

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

78

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

79

A study of a tissue equivalent gelatine based tissue substitute  

SciTech Connect

A study of several tissue substitutes for use as volumetric dosimeters was performed. The tissue substitutes studied included tissue substitutes from previous studies and from ICRU 44. The substitutes were evaluated for an overall match to Reference Man which was used as a basis for this study. The evaluation was based on the electron stopping power, the mass attenuation coefficient, the electron density, and the specific gravity. The tissue substitute chosen also had to be capable of changing from a liquid into a solid form to maintain an even distribution of thermoluminesent dosimetry (TLD) powder and then back to a liquid for recovery of the TLD powder without adversely effecting the TLD powder. The gelatine mixture provided the closest match to the data from Reference Man tissue. The gelatine mixture was put through a series of test to determine it`s usefulness as a reliable tissue substitute. The TLD powder was cast in the gelatine mixture and recovered to determine if the TLD powder was adversely effected. The distribution of the TLD powder after being cast into the gelatin mixture was tested in insure an even was maintained.

Spence, J.L.

1992-11-01

80

A study of a tissue equivalent gelatine based tissue substitute  

SciTech Connect

A study of several tissue substitutes for use as volumetric dosimeters was performed. The tissue substitutes studied included tissue substitutes from previous studies and from ICRU 44. The substitutes were evaluated for an overall match to Reference Man which was used as a basis for this study. The evaluation was based on the electron stopping power, the mass attenuation coefficient, the electron density, and the specific gravity. The tissue substitute chosen also had to be capable of changing from a liquid into a solid form to maintain an even distribution of thermoluminesent dosimetry (TLD) powder and then back to a liquid for recovery of the TLD powder without adversely effecting the TLD powder. The gelatine mixture provided the closest match to the data from Reference Man tissue. The gelatine mixture was put through a series of test to determine it's usefulness as a reliable tissue substitute. The TLD powder was cast in the gelatine mixture and recovered to determine if the TLD powder was adversely effected. The distribution of the TLD powder after being cast into the gelatin mixture was tested in insure an even was maintained.

Spence, J.L.

1992-11-01

81

Composite PTCR thermistors utilizing conducting borides, silicides, and carbide powders  

Microsoft Academic Search

Ceramic-polymer composite thermistors using conducting boride, silicide, and carbide powders that include TiB2, ZrB2, NbB2, NbSi2, WSi2, MoSi2, and TiC have been fabricated. Percolation and subsequent PTCR effects were observed for all the powders in both semi-crystalline (polyethylene) and amorphous (epoxy) polymer matrix materials, however, as found for carbon black and metal fillers, both niobate powders did not exhibit a

T. R. Shrout; D. Moffatt; W. Huebner

1991-01-01

82

Physicochemical and Sensory Characteristics of Crackers (Kerupuk) Formulated with Surimi Powder  

Microsoft Academic Search

Surimi powder can be used to substitute flour in the formulation of Indonesian crackers (kerupuk). Three different levels of surimi powder (10%, 20%, and 30%) were substituted in the flour used. Physicochemical analyses were conducted on four different kerupuk formulations. The resulting kerupuk were subjected to sensory evaluation using Indonesian school children, aged from 9 - 20 years as a

Nurul Huda; Aminah Abdullah; Abdul Salam Babji

83

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) [Greensburg, PA

1988-01-01

84

Powder treatment process  

DOEpatents

Disclosed are: (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. 2 figs.

Weyand, J.D.

1988-02-09

85

Mechanics of Powder Plastic Powder Compacts.  

National Technical Information Service (NTIS)

Colloidal Isopressing is a new method for the shaping of ceramic components from powder suspensions in a rapid and effective manner. Colloidal Isopressing starts with a slurry containing a relatively low volume fraction of powder, where the particles weak...

F. F. Lange

2001-01-01

86

Blood substitutes.  

PubMed

The toxic side effects of early generations of red blood cell substitutes have stimulated development of more safe and efficacious high-molecular-weight polymerized hemoglobins, poly(ethylene glycol)-conjugated hemoglobins, and vesicle-encapsulated hemoglobins. Unfortunately, the high colloid osmotic pressure and blood plasma viscosity of these new-generation materials limit their application to blood concentrations that, in general, are not sufficient for full restoration of oxygen-carrying and -delivery capacity. However, these materials may serve as oxygen therapeutics for treating tissues affected by ischemia and trauma, particularly when the therapeutics are coformulated with antioxidants. These new oxygen therapeutics also possess additional beneficial effects owing to their optimal plasma expansion properties, which induce systemic supraperfusion that increases endothelial nitric oxide production and improves tissue washout of metabolic wastes, further contributing to their therapeutic role. PMID:24819476

Palmer, Andre F; Intaglietta, Marcos

2014-07-11

87

Some initial experiments with an electrically conducting powder under static and vibrating conditions  

Microsoft Academic Search

An electrically conducting powder was produced by mixing bronze spheres with a small amount of carbon black powder. The potential difference across beds of this powder was measured under static conditions and vibration. The system was very sensitive and monitored changes during vibration cycles at rapid rates. Horizontal and vertical conductances were measured. Above a minimum vertical stress, the ratio

A. J. Matchett; T. Yanagida; Y. Okudaira; S. Kobayashi; M. Satoh

1999-01-01

88

Ceramic powder synthesis in supercritical fluids  

SciTech Connect

Gas-phase processing plays an important role in the commercial production of a number of ceramic powders. These include titanium dioxide, carbon black, zinc oxide, and silicon dioxide. The total annual output of these materials is on the order of 2 million tons. The physical processes involved in gas-phase synthesis are typical of those involved in solution -phase synthesis: chemical reaction kinetics, mass transfer, nucleation, coagulation, and condensation. This report focuses on the work done under a Laboratory-Directed Research and Development (LDRD) project that explored the use of various high pressure techniques for ceramic powder synthesis. Under this project, two approaches were taken. First, a continuous flow, high pressure water reactor was built and studied for powder synthesis. And second, a supercritical carbon dioxide static reactor, which was used in conjunction with surfactants, was built and used to generate oxide powders.

Adkins, C.L.J.; Russick, E.M.; Cesarano, J; Tadros, M.E.; Voigt, J.A.

1996-04-01

89

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

90

40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.  

Code of Federal Regulations, 2010 CFR

...false Substituted pyridine azo substituted phenyl. 721.8780 Section...8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance...generically as substituted pyridine azo substituted phenyl (PMNs P-96-767...

2009-07-01

91

POWDERS FOR EXTINGUISHING FIRES  

Microsoft Academic Search

The development of a powder suitable for extinguishing fires of burning ; U, Pu, or Th is described. The powder consists of a mixture of powdered ; inorganic chlorides and\\/or fluorides inert towards the bunning metal. The ; mixture has a melting point below the melting point of the burning metal such ; that fusion of the powder takes place

Cope

1963-01-01

92

Resin-Powder Dispenser  

NASA Technical Reports Server (NTRS)

Resin-powder dispenser used at NASA's Langley Research Center for processing of composite-material prepregs. Dispenser evenly distributes powder (resin polymer and other matrix materials in powder form) onto wet uncured prepregs. Provides versatility in distribution of solid resin in prepreg operation. Used wherever there is requirement for even, continuous distribution of small amount of powder.

Standfield, Clarence E.

1994-01-01

93

Characterization of Fine Powders  

NASA Astrophysics Data System (ADS)

Fine powders are used in many applications and across many industries such as powdered paints and pigments, ceramics, petrochemicals, plastics, pharmaceuticals, and bulk and fine chemicals, to name a few. In addition, fine powders must often be handled as a waste by-product, such as ash generated in combustion and gasification processes. In order to correctly design a process and process equipment for application and handling of powders, especially fine powders, it is essential to understand how the powder would behave. Many characterization techniques are available for determining the flow properties of powders; however, care must be taken in selecting the most appropriate technique(s).

Krantz, Matthew; Zhang, Hui; Zhu, Jesse

94

Preparation of titanium diboride powder  

SciTech Connect

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, J.; Bamberger, C.E.

1985-03-05

95

Black tea  

MedlinePLUS

... much medicine the body absorbs. To avoid this interaction, avoid black tea 1 hour before and 2 ... much medicine the body absorbs. To avoid this interaction, avoid black tea 1 hour before and 2 ...

96

Black Cohosh  

MedlinePLUS

... miscarriage , and relief of labor pains) [ 4 ]. What clinical studies have been done on black cohosh and ... cohosh can cause stomach discomfort and headaches [ 10 ]. Clinical trials comparing estrogens with black cohosh preparations have ...

97

Black Psychology.  

ERIC Educational Resources Information Center

The contents of the present volume, designed to bring together in a single place writings by the new black psychologists and other black social and behavioral scientists, are organized in seven parts, as follows: Part I, "Black Psychology: Perspectives," includes articles by Cedric Clark, Wade W. Nobles, Doris P. Mosby, Joseph White, and William…

Jones, Reginald L., Ed.

98

Black Holes  

NASA Astrophysics Data System (ADS)

Foreword to the French edition; Foreword to the English edition; Acknowledgements; Part I. Gravitation and Light: 1. First fruits; 2. Relativity; 3. Curved space-time; Part II. Exquisite Corpses: 4. Chronicle of the twilight years; 5. Ashes and diamonds; 6. Supernovae; 7. Pulsars; 8. Gravitation triumphant; Part III. Light Assassinated: 9. The far horizon; 10. Illuminations; 11. A descent into the maelstrom; 12. Map games; 13. The black hole machine; 14. The quantum black hole; Part IV. Light Regained: 15. Primordial black holes; 16. The zoo of X-ray stars; 17. Giant black holes; 18. Gravitational light; 19. The black hole Universe; Appendices; Bibliography; Name index; Subject index.

Luminet, Jean-Pierre

1992-09-01

99

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.

Evans, Douglas E.; Baron, Paul A.

2013-01-01

100

Black Holes: And Black Magic  

Microsoft Academic Search

\\u000a Black Holes and Black Magic? No true connection, needless to say, but black holes are so bizarre that they really do seem\\u000a to be magical. Even now we cannot pretend that we have anything like a full understanding of them.

Patrick Moore

101

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

102

Ceramic powder compaction.  

National Technical Information Service (NTIS)

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 experime...

S. J. Glass K. G. Ewsuk F. M. Mahoney

1995-01-01

103

Carbothermal synthesis of titanium carbide using ultrafine titania powders  

Microsoft Academic Search

The synthesis of titanium carbide (TiC) by the carbothermal reduction of carbon coated titanium dioxide (TiO2), a novel synthesis process, and titanium dioxide (TiO2) mixed with carbon black was investigated. A high surface area (64 m2g-1) TiO2 powder consisting of anatase and rutile phases was used for starting powders. The carbon coated method is a two-step process that utilizes a

R. KOC; J. S Folmer

1997-01-01

104

Single crystalline and rare earth substituted La{sub 2}RuO{sub 5} investigated by x-ray diffraction and EXAFS spectroscopy  

SciTech Connect

Single crystals of La{sub 2}RuO{sub 5} were obtained from a BaCl{sub 2} flux. The structure was determined by single crystal x-ray diffraction and compared to earlier x-ray and neutron powder diffraction results. The local structures of Ru and La/Ln in pure La{sub 2}RuO{sub 5} and the rare earth substituted La{sub 2-x}Ln{sub x}RuO{sub 5} (Ln=Pr, Nd, Sm, Gd, Dy) polycrystalline samples were determined from the extended x-ray absorption fine structures (EXAFS) of the K- and L{sub III}-edges of Ru, La, and Ln, respectively. A four shell model was developed to reduce the number of refinable parameters in the fit of the EXAFS spectra. The distribution of the Ln-ions in the layered crystal structure was determined by a comparison of the coordination spheres obtained from the Ln-edges with the unsubstituted La{sub 2}RuO{sub 5}. Interatomic distances were compared to the values obtained from the single crystal diffraction and were found to agree very well. - Graphical abstract: The crystal structure of La{sub 2-x}Ln{sub x}RuO{sub 5} (Ln=Pr, Nd, Sm, Gd, Dy) is shown viewed along the c-axis. The alternating stacking of LaRuO{sub 4} and LnO layers leads to the formation of zig-zag layers of corner sharing RuO{sub 6} octahedra. The La sites in the LaRuO{sub 4} layers are represented by light blue spheres, while the La/Ln sites in the LnO layers are colored dark blue. EXAFS investigations reveal a cationic ordering with roughly 65% of the substituting Ln ions occupying the LnO layers. Highlights: Black-Right-Pointing-Pointer Structure determination of La{sub 2}RuO{sub 5} by single crystal x-ray diffraction. Black-Right-Pointing-Pointer Ru-K EXAFS investigations of La{sub 2-x}Ln{sub x}RuO{sub 5} powder samples. Black-Right-Pointing-Pointer EXAFS of La and Ln in La{sub 2-x}Ln{sub x}RuO{sub 5} powder samples using K- and L{sub III}-absorption edges. Black-Right-Pointing-Pointer Good agreement of EXAFS results and crystal structure data despite low symmetry space group. Black-Right-Pointing-Pointer Observed partial cationic ordering of the inserted Ln on the two La sites.

Riegg, S., E-mail: stefan.riegg@physik.uni-augsburg.de [Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, D - 86135 Augsburg (Germany); Reller, A. [Resource Strategy, University of Augsburg, D - 86135 Augsburg (Germany); Ebbinghaus, S.G. [Solid State Chemistry, Martin-Luther University Halle-Wittenberg, D - 06099 Halle (Germany)

2012-04-15

105

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

106

Co-substitution at the Mn-site in YMnO{sub 3}: Structural stability and physical properties  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Solid state synthesis of several series of hexagonal co-substituted YMn{sub 1-x}(M Prime ,M Double-Prime ){sub x}O{sub 3}. Black-Right-Pointing-Pointer Evidencing the critical parameters which govern the stabilization of the hexagonal phase. Black-Right-Pointing-Pointer Inducing a decrease of the antiferromagnetic ordering temperature by co-substitutions. -- Abstract: The YMnO{sub 3} oxide, crystallizing in the P6{sub 3}cm space group is one of the most studied multiferroic material. While these properties can be modified by substitutions at the Mn-site, the peculiar fivefold coordination appears to limit the M solubility range in YMn{sub 1-x}M{sub x}O{sub 3}. This motivated the preparation by solid state reaction of several series of co-substituted YMn{sub 1-x}(M Prime ,M Double-Prime ){sub x}O{sub 3}, which were studied using both powder X-ray diffraction and transmission electron microscopy. The cation pairs have been chosen for their ability to adopt a fivefold coordination similar to that of Mn{sup 3+} in YMnO{sub 3}, to keep a constant average trivalent oxidation state and to maintain an average cationic radius similar to that of Mn{sup 3+}. For YMn{sub 1-x}(Cu{sub 1/2}Ti{sub 1/2}){sub x}O{sub 3}, a complete solid solution is observed without cation ordering. For all other studied cation pairs, the solubility range is always reaching a minimum value of 25% for the Zn containing pairs (Zn{sub 2/3}V{sub 1/3} and Zn{sub 3/4}Mo{sub 1/4}), a maximum of 50% being reached for the Cu containing pairs (Cu{sub 2/3}V{sub 1/3}, Cu{sub 2/3}Nb{sub 1/3} and Cu{sub 3/4}W{sub 1/4}). Interestingly, the non-centrosymmetric P6{sub 3}cm space group is retained within the solubility range without generating cation ordering phenomena. These co-substitutions at the Mn{sup 3+} are found to induce a decrease of the antiferromagnetic ordering temperature, the T{sub N} variations being similar to the temperature decrease of the dielectric anomaly. Thus, these oxides are interesting candidates for the study of the multiferroic behavior of YMnO{sub 3} derivatives.

Malo, S., E-mail: sylvie.malo@ensicaen.fr [CNRS - UMR 6508-CRISMAT, 14050 Caen (France); ENSICAEN - UMR 6508-CRISMAT, 14050 Caen (France); Universite de Caen Basse-Normandie - UMR 6508-CRISMAT, 14050 Caen (France); Maignan, A. [CNRS - UMR 6508-CRISMAT, 14050 Caen (France) [CNRS - UMR 6508-CRISMAT, 14050 Caen (France); ENSICAEN - UMR 6508-CRISMAT, 14050 Caen (France); Universite de Caen Basse-Normandie - UMR 6508-CRISMAT, 14050 Caen (France)

2012-04-15

107

Black algae  

Microsoft Academic Search

Many species of cyanophytes, especially those growing on tiles and walls exposed to air and sunlight, appear black due to the presence of pigments in the mucilaginous cell-walls. Such pigments may serve a protective role against adverse effects of ultraviolet light but, overlying the ordinary intracellular blue-green pigments, they make the algal clumps look black. Among the most familiar of

Ralph A. Lewin

2006-01-01

108

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.

109

Nucleophilic Aromatic Substitution.  

ERIC Educational Resources Information Center

Described is a microscale organic chemistry experiment which demonstrates one feasible route in preparing ortho-substituted benzoic acids and provides an example of nucleophilic aromatic substitution chemistry. Experimental procedures and instructor notes for this activity are provided. (CW)

Avila, Walter B.; And Others

1990-01-01

110

Compositions and Methods Containing Substituted Quinolines and Substituted Diphenylsufones.  

National Technical Information Service (NTIS)

Combination therapies of substituted quinolines and substituted diphenyl sulfones are disclosed. More specifically, compositions containing substituted quinolines and substituted diphenyl sulfones are disclosed. In addition, methods of using the compositi...

D. J. Giulian D. P. Jacobus

2004-01-01

111

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

112

40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...  

Code of Federal Regulations, 2010 CFR

...substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl...

2009-07-01

113

Powders for magnetoabrasive machining  

Microsoft Academic Search

Conclusions On the basis of literature data an analysis is made of the abrasive power and magnetic properties of powders of various magnetoabrasive materials and of the degree of interaction between their magnetic and abrasive constituents. It is concluded that the greatest potentiality for MAP is shown by materials containing a refractory compound powder as their abrasive component and an

G. D. Nalivka; A. N. Stepanchuk; L. N. Tul'chinskii

1976-01-01

114

Aluminum powder applications  

Microsoft Academic Search

Aluminum powders have physical and metallurgical characteristics related to their method of manufacture that make them extremely important in a variety of applications. They can propel rockets, improve personal hygiene, increase computer reliability, refine exotic alloys, and reduce weight in the family sedan or the newest Air Force fighter. Powders formed into parts for structural and non-structural applications hold the

Gurganus

1995-01-01

115

Black Cohosh  

MedlinePLUS

... as stomach discomfort, headache, or rash. In general, clinical trials of black cohosh for menopausal symptoms have ... Is CAM? Safety Information For Health Care Professionals Clinical Practice Guidelines Literature Reviews More » Research NCCAM Research ...

116

Microwave assisted solid state reaction synthesis of MgAl 2O 4 spinel powders  

Microsoft Academic Search

Stoichiometric MgAl2O4 spinel powders were synthesized by microwave assisted solid-state reaction (MWSSR powders) in a domestic microwave (MW) oven (2.45 GHz frequency, 700 W power) from aluminum tri-hydroxide and caustic MgO in the presence of carbon black (10–50 wt.% with respect to total raw mix). 20% C was found to be sufficient to produce spinel powder with 82% spinel content

Ibram Ganesh; Bakki Srinivas; Roy Johnson; Bhaskar P Saha; Yashwant R Mahajan

2004-01-01

117

B 4C\\/TiB 2 composite powders prepared by carbothermal reduction method  

Microsoft Academic Search

B4C–(10–20vol%)TiB2 composite powders have been synthesized with the temperature of 1650–1800°C by carbothermal reduction process using boron acid, carbon black and TiO2 powder as the starting materials. B\\/C mole ratio of the starting materials is ascertained, thermodynamics temperature of the reactions is calculated and the effect of ball milling on the composite powders is discussed. The experimental results indicate that

L. Z. Pei; H. N. Xiao

2009-01-01

118

Synthesis of high surface area ZnO powder by continuous precipitation  

SciTech Connect

Graphical abstract: High surface area ZnO powders are synthesized by a low temperature continuous precipitation under ultrasonication. Urea is used as precipitating agent so that no contamination of ZnO powder emanating from precipitating agent, such as, alkalis, is observed. pH and type of precursor greatly affects the surface area and other properties. In this manuscript, we report a very simple and effective continuous precipitation to synthesize high surface area ZnO powder. Highlights: Black-Right-Pointing-Pointer The synthesis of high surface area ZnO powder was achieved at 90 Degree-Sign C in a continuous precipitation unit. Black-Right-Pointing-Pointer Continuous precipitation unit was ultrasonicated to improve final product homogeneity. Black-Right-Pointing-Pointer Precipitation intermediate, hydrozincite, was led to high surface area ZnO powder. Black-Right-Pointing-Pointer The synthesized ZnO nanoparticles had a rather uniform mesoporous structure. -- Abstract: Synthesis of high surface area ZnO powder was achieved by continuous precipitation using zinc ions and urea at low temperature of 90 Degree-Sign C. The powder precipitated resulted in high-purity single-phase ZnO powder when calcined at 280 Degree-Sign C for 3 h in air. The solution pH and the precipitation duration strongly affected the surface area of the calcined ZnO powder. Detailed structural characterizations demonstrated that the synthesized ZnO powder were single crystalline with wurtzite hexagonal phase. The powdered samples precipitated by homogeneous precipitation crystallized directly to hydrozincite without any intermediate phase formation. The phase structures, morphologies and properties of the final ZnO powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering particle size analysis (DLS), and nitrogen physisorption in order to determine the specific surface area (BET) and the pore size distribution (BJH).

Boz, Ismail, E-mail: ismailb@istanbul.edu.tr [Istanbul University, Faculty of Engineering, Department of Chemical Engineering, Avcilar, Istanbul 34320 (Turkey)] [Istanbul University, Faculty of Engineering, Department of Chemical Engineering, Avcilar, Istanbul 34320 (Turkey); Kaluza, Stefan [Laboratory of Industrial Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, Bochum 44780 (Germany)] [Laboratory of Industrial Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, Bochum 44780 (Germany); Boroglu, Mehtap Safak [Istanbul University, Faculty of Engineering, Department of Chemical Engineering, Avcilar, Istanbul 34320 (Turkey)] [Istanbul University, Faculty of Engineering, Department of Chemical Engineering, Avcilar, Istanbul 34320 (Turkey); Muhler, Martin [Laboratory of Industrial Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, Bochum 44780 (Germany)] [Laboratory of Industrial Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, Bochum 44780 (Germany)

2012-05-15

119

Vacuum Powder Injector  

NASA Technical Reports Server (NTRS)

Method developed to provide uniform impregnation of bundles of carbon-fiber tow with low-solubility, high-melt-flow polymer powder materials to produce composite prepregs. Vacuum powder injector expands bundle of fiber tow, applies polymer to it, then compresses bundle to hold powder. System provides for control of amount of polymer on bundle. Crystallinity of polymer maintained by controlled melt on takeup system. All powder entrapped, and most collected for reuse. Process provides inexpensive and efficient method for making composite materials. Allows for coating of any bundle of fine fibers with powders. Shows high potential for making prepregs of improved materials and for preparation of high-temperature, high-modulus, reinforced thermoplastics.

Working, Dennis C.

1991-01-01

120

Compaction of Titanium Powders  

NASA Astrophysics Data System (ADS)

Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines <150 ?m, <75 ?m, and < 45 ?m; two different sizes of a hydride-dehydride [HDH] <75 ?m and < 45 ?m; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

Gerdemann, Stephen J.; Jablonski, Paul D.

2011-05-01

121

Compaction of Titanium Powders  

SciTech Connect

Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines<150 {micro}m,<75 {micro}m, and<45 {micro}m; two different sizes of a hydride-dehydride [HDH]<75 {micro}m and<45 {micro}m; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

Gerdemann, Stephen,J; Jablonski, Paul, J

2011-05-01

122

Sintering titanium powders  

SciTech Connect

Recently, there has been renewed interest in low-cost titanium. Near-net-shape powder metallurgy offers the potential of manufacturing titanium articles without costly and difficult forming and machining operations; hence, processing methods such as conventional press-and-sinter, powder forging and powder injection molding are of interest. The sintering behavior of a variety of commercial and experimental titanium powders was studied. Commercial powders were acquired that were produced different routes: (i) sponge fines from the primary titanium processing; (ii) via the hydride-dehydride process; and (iii) gas atomization. The influence of vacuum sintering time (0.5 to 32 hrs) and temperature (1200, 1275 or 1350°C) on the microstructure (porosity present) of cold pressed powders was studied. The results are discussed in terms of the difference in powder characteristics, with the aim of identify the characteristics required for full density via press-and-sinter processing. Near-net-shape tensile bars were consolidated via cold pressed and sintered. After sintering, a sub-set of the tensile bars was hot-isostatic pressed (HIPed). The microstructure and properties of the bars were compared in the sintered and HIPed conditions.

Gerdemann, Stephen J.; Alman, David E.

2005-09-01

123

A study of La-substituted strontium hexaferrite by hydrothermal synthesis  

Microsoft Academic Search

The possibility of replacing Sr by La and Fe by Co and the subsequent improvement of the magnetic properties of the M-type ferrite stimulated our interest in studying other rare-earth ion substitutions. We have found that Sm and Nd substitutions can increase the coercivity of the hydrothermally synthesised Sr hexaferrite powder without causing any significant fall in the saturation magnetisation.

J. F Wang; C. B Ponton; R Grössinger; I. R Harris

2004-01-01

124

A study of Pr-substituted strontium hexaferrite by hydrothermal synthesis  

Microsoft Academic Search

The possibility of replacing Sr by La and Fe by Co and the subsequent improvement of the magnetic properties of the M-type ferrite stimulated our interest in studying other rare-earth ion substitutions. We have found that Sm and Nd substitutions can increase the coercivity of the hydrothermally synthesised Sr hexaferrite powder without causing any significant fall in the saturation magnetisation.

J. F. Wang; C. B. Ponton; I. R. Harris

2005-01-01

125

Formulation and physicochemical and sensorial evaluation of biscuit-type cookies supplemented with fruit powders.  

PubMed

Cashew apple and guava residues from fruit juice industry were prepared as dehydrated fruit powders and used at different levels of wheat flour substitution for cookies formulations. The effects of guava and cashew apple fruit powders supplementation on physicochemical and sensorial characteristics of the cookies were evaluated. The pH, fibre and protein content were significantly affected. Biscuits with 15 g and 20 g/100g cashew apple and guava fruit powders showed the highest scores for sensorial attributes, respectively. The supplementation seems to be suited for wheat flour substitution and it is possible to obtain cookies with value-added food ingredient within the standards. PMID:19455423

Uchoa, Ana Maria Athayde; Correia da Costa, José Maria; Maia, Geraldo Arraes; Meira, Tatyane Ribeiro; Sousa, Paulo Henrrique Machado; Montenegro Brasil, Isabella

2009-06-01

126

The Crisis in Black and Black.  

ERIC Educational Resources Information Center

These essays explore why the historic conflict between blacks and whites in the United States has become a crisis that divides many African Americans. The changing racial dynamic is not marked by conflicts. between the black middle class and the poor, black men and women, the black intellectual elite and rappers, black politicians and the urban…

Hutchinson, Earl Ofari

127

Infrared photoacoustic spectroscopy of adsorption on powders  

NASA Astrophysics Data System (ADS)

A photoacoustic cell for adsorption spectroscopy on powders is described. The cell permits spectra to be obtained, with a flowing gas and temperatures up to 400°C. Experiments were performed examining methanol adsorption on silica and Na-Y zeolites. On the silica, methoxy groups quantitatively displaced surface hydroxyl groups at elevated temperatures. On the Na zeolite, methanol seemed to associate with cation centers. The photoacoustic spectra were able to clearly display the entire spectrum from 4000-400 cm -1, and the methoxy C-O stretching band was clearly visible superimposed on the Si-O bands. Adsorption studies of CO on Pt/Al 2O 3 and Pt-black showed that photoacoustic spectra could be obtained for supported metal catalysts, but not for massive metal catalysts. Criteria are presented that relate the applicability of PAS to the physical properties of the powder.

McGovern, S. J.; Royce, B. S. H.; Benziger, J. B.

1984-09-01

128

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

129

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

130

Black Racial Attitudes: Trends and Complexities.  

ERIC Educational Resources Information Center

The slogan "study the victimizers, not the victims," can too easily become an excuse for substituting the ideologies and preconceptions of white and black intellectuals for the often different reality revealed by empirical research. This monograph tries to present a modest but complex set of data gathered using attitude sample survey methods, and…

Schuman, Howard; Hatchett, Shirley

131

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

132

Specific surface area and chemical reactivity of quartz powders during mechanical processing  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Quartz powders were submitted to mechanical processing. Black-Right-Pointing-Pointer The specific surface area and the chemical reactivity increased. Black-Right-Pointing-Pointer A model was developed to describe the observed processes. Black-Right-Pointing-Pointer The amount of powder processed at impact was estimated. Black-Right-Pointing-Pointer The surface density of reactive centers was also estimated by using a test reaction. -- Abstract: The present work focuses on the specific surface area increase, and on the related chemical reactivity enhancement of quartz powders submitted to mechanical processing. The mechanical treatment was carried out in a suitably developed ball mill allowing the control of the frequency and energy of the impacts between ball and reactor. The specific surface area was directly measured by nitrogen physisorption, whereas electron microscopy was used to determine the size distribution of powder particles. Based on the experimental results, a simplified mathematical model was developed to describe the process of specific surface area increase on a phenomenological basis. The model permits to gain valuable information on the amount of powder processed in individual impacts. The density of reactive centers at the surface of powder particles was also estimated by using the neutralization of a free radical as a test reaction. It is shown that the surface density of reactive centers increases with the energy of collisions.

Meloni, Paola [Dipartimento di Ingegneria Chimica e Materiali, Universita degli Studi di Cagliari, piazza d'Armi, I-09123 Cagliari (Italy) [Dipartimento di Ingegneria Chimica e Materiali, Universita degli Studi di Cagliari, piazza d'Armi, I-09123 Cagliari (Italy); Laboratorio per lo studio dei Materiali 'Colle di Bonaria', Universita degli Studi di Cagliari, via Ravenna, I-09100 Cagliari (Italy); Carcangiu, Gianfranco [Laboratorio per lo studio dei Materiali 'Colle di Bonaria', Universita degli Studi di Cagliari, via Ravenna, I-09100 Cagliari (Italy) [Laboratorio per lo studio dei Materiali 'Colle di Bonaria', Universita degli Studi di Cagliari, via Ravenna, I-09100 Cagliari (Italy); Istituto di Geologia Ambientale e Geoingegneria (IGAG), CNR, piazza d'Armi, I-09123 Cagliari (Italy); Delogu, Francesco, E-mail: delogu@dicm.unica.it [Dipartimento di Ingegneria Chimica e Materiali, Universita degli Studi di Cagliari, piazza d'Armi, I-09123 Cagliari (Italy)] [Dipartimento di Ingegneria Chimica e Materiali, Universita degli Studi di Cagliari, piazza d'Armi, I-09123 Cagliari (Italy)

2012-01-15

133

Microwave-hydrothermal synthesis of Al-substituted tobermorite from zeolites  

Microsoft Academic Search

Here, we report the rapid synthesis of Al-substituted tobermorites from zeolites under microwave-hydrothermal (M-H) conditions. The synthesized phases were characterized by powdered XRD analysis, SEM and selective Cs exchange determination. Zeolites served as aluminosilicate sources and M-H conditions yielded highly crystalline Al-substituted tobermorites in 2h at 180°C and they showed high selectivity for Cs. For example, an Al-substituted tobermorite synthesized

Sridhar Komarneni; Jayanth S Komarneni; Bharat Newalkar; Stephen Stout

2002-01-01

134

Mystery Powder Investigation  

NSDL National Science Digital Library

Students will use their skills as scientists to identify a mystery white powder. This lesson is a hands-on, engaging way to build students' understanding of physical and chemical properties of several common compounds.

Hallettnjuguna, Rachel

2012-07-27

135

Combustibility of titanium powders  

NASA Technical Reports Server (NTRS)

The combustion of compact samples was studied; the mechanism of autoignition is defined. Several studies are made of the combustibility of titanium using 50 samples. The data provide a clear idea of the combustibility of titanium powders.

Popov, Ye. I.; Poyarkov, V. G.; Finayev, Yu. A.

1989-01-01

136

Some Candidate Louse Powders.  

National Technical Information Service (NTIS)

During the past several years, several new candidate louse powders have been developed through a cooperative program between the U. S. Department of Agriculture and the Department of Defense. These compounds include Abate, Cidial, Mobam, Carbaryl and GS-1...

M. M. Cole P. H. Clark R. H. Grothaus

1973-01-01

137

Gelcasting superalloy powders  

SciTech Connect

Gelcasting is a process for forming inorganic powders into complex shapes. It was originally developed for ceramic powders. A slurry of powder and a monomer solution is poured in to mold and polymerized in-situ to form gelled parts. Typically, only 2-4 wt % Polymer is used. The process has both aqueous and nonaqueous versions. Gelcasting is a generic process and has been used to produce ceramic parts from over a dozen different ceramic compositions ranging from alumina-based refractories to high-performance silicon nitride. Recently, gelcasting has been applied to forming superalloy powders into complex shapes. This application has posed several challenges not previously encountered in ceramics. In particular, problems were caused by the larger particle size and the higher density of the particles. Additional problems were encountered with binder removal. How these problems were overcome will be described.

Janney, M.A.

1995-12-31

138

Hepagene (PowderJect).  

PubMed

Celltech Group (formerly Medeva) developed Hepagene, a recombinant polyvalent vaccine with potential activity against hepatitis B virus infections [353474]. In September 2000, PowderJect acquired the product as part of its acquisition of Celltech's vaccine manufacturing business [381557]. In July 2001, PowderJect reported that evaluation was nearing completion. At this time, the company expected to launch the vaccine in the coming months [443490]. Hepagene is a polyvalent vaccine with S, pre-S1 and pre-S2 hepatitis B epitopes forming the basis of its antigenicity. Additionally, these surface markers have been glycosylated in order to resemble the live virus more closely [254780]. By June 2000, Celltech and PowderJect were evaluating Hepagene, utilizing PowderJect's needle-less injection technology [379536]. In December 1999, Lehman Brothers predicted that the product had a 50% chance of reaching the treatment (rather than prevention) market, with potential peak sales of US $600 million [352078]. PMID:12186276

Jones, Taff

2002-07-01

139

Black Literature vs. Black Studies: Three Lynchings  

ERIC Educational Resources Information Center

Considers three works by black authors, all dealing with lynchings, that may be used in a black literature course to introduce students to the esthetic dimension of black literature, as well as to its cultural and racial significance. (GW)

Williams, Melvin G.

1977-01-01

140

Textured powder wires  

US Patent & Trademark Office Database

A method for fabricating a wire from textured powder includes compressing a powder comprising a plurality of particles into a ribbon. The method further includes encasing the ribbon between two foil sheets to create a sheet of encased ribbon. The method additionally includes rolling the encased ribbon into a substantially cylindrical undrawn wire. The method further includes drawing the undrawn wire to create a substantially cylindrical wire having a diameter less than a diameter of the substantially cylindrical undrawn wire.

2013-11-26

141

Powder Core Dielectric Waveguides  

Microsoft Academic Search

A powder-filled surface of a led groove in the teflon substrate has been demonstrated as a dielectric waveguide at 94 GHz. Guide wavelengths measured for combinations of guide dimensions and powders agree within 10% of values predicted by Marcatili 's approximate theory. Attenuation constants of 0.2 to 0.3 dB\\/cm were measured for barium tetra-titanate.

W. M. Bruno; W. B. Bridges

1984-01-01

142

Black Smokers  

NSDL National Science Digital Library

This brief web article features black smokers and discusses the history of their discovery, the geologic processes creating black smokers, and the various life forms inhabiting this extreme environment. As part of the PBS "Savage Earth" series, the site contains animations of basic geologic processes, QuickTime videos and additional web articles discussing the ring of fire, the Kola well in Russia, the internal structure of the Earth, earthquakes, volcanoes, and tsunamis. This website also provides a link to the PBS home, where other PBS online programs can be found. The QuickTime program is required to view the videos and can be downloaded free of charge on site.

Svitil, Kathy A.

2009-06-23

143

Thermal properties of carbon black aqueous nanofluids for solar absorption  

PubMed Central

In this article, carbon black nanofluids were prepared by dispersing the pretreated carbon black powder into distilled water. The size and morphology of the nanoparticles were explored. The photothermal properties, optical properties, rheological behaviors, and thermal conductivities of the nanofluids were also investigated. The results showed that the nanofluids of high-volume fraction had better photothermal properties. Both carbon black powder and nanofluids had good absorption in the whole wavelength ranging from 200 to 2,500 nm. The nanofluids exhibited a shear thinning behavior. The shear viscosity increased with the increasing volume fraction and decreased with the increasing temperature at the same shear rate. The thermal conductivity of carbon black nanofluids increased with the increase of volume fraction and temperature. Carbon black nanofluids had good absorption ability of solar energy and can effectively enhance the solar absorption efficiency.

2011-01-01

144

The Black Books Roundup.  

ERIC Educational Resources Information Center

Lists "Black and Black related" books available from American and some British publishing companies. Also provides lists of publishers and bookstores that carry works relevant to Blacks and Black studies. (GC)

Black Scholar, 1982

1982-01-01

145

Bone substitutes: new concepts  

Microsoft Academic Search

The filling of bone defects resulting from trauma or surgical resections of tumors requires bone grafts or bone substitutes. Bone substitute must be biocompatible, osteoconductive, and must present good mechanical properties. Among biomaterials classicaly used, calcium phosphate ceramic appear to be suitable alternatives to bone grafts. Calcium phosphate are known able to promote new bone formation on contact and have

D. Heymann; N. Passuti

1999-01-01

146

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

147

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

148

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

149

Counseling Blacks  

ERIC Educational Resources Information Center

Blacks have developed unique environmental perceptions, values, and attitudes, making it difficult for counselors to establish and maintain positive rapport. This article examines attitudinal ingredients posited by Carl Rogers for relevance to this problem, and suggests in-service training to help counselors and other professionals relate…

Vontress, Clemmont E.

1970-01-01

150

Black Adolescents.  

ERIC Educational Resources Information Center

This volume presents an overview of contemporary black adolescents from social, psychological, economic, educational, medical, historical, and comparative perspectives, with most emphasizing the roles that race, socioeconomic status, and environmental forces play in this critical period. The volume includes 19 chapters by various authors arranged…

Jones, Reginald L., Ed.

151

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

152

Low-temperature synthesis of sinterable SiC powders by carbothermic reduction of colloidal SiO 2  

Microsoft Academic Search

ß-SiC powders were synthesised by carbothermic reduction of carbon-black doped silica gel. The morphological characteristics of the resulting powders depend on the morphology of precursor carbon black as well as the reaction conditions. A model for particle coarsening during carbothermic reduction is presented, suggesting that surface diffusion may be responsible for the formation of polycrystalline aggregates, while at higher reaction

V. M. Kevorkijan; M. Komac; D. Kolar

1992-01-01

153

Skin Substitutes and Uses Thereof.  

National Technical Information Service (NTIS)

The present invention relates to in vitro cultured skin substitutes, and in particular to improved methods for organotypic culture of skin substitutes. In some embodiments, the dermal equivalent of the skin substitute is lifted to air interface of the cul...

C. A. R. Ivarie L. A. Hoffman P. Barth

2004-01-01

154

Iowa Powder Atomization Technologies  

ScienceCinema

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

2013-03-01

155

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

156

Powder towpreg process development  

NASA Technical Reports Server (NTRS)

The process for dry powder impregnation of carbon fiber tows being developed at LaRC overcomes many of the difficulties associated with melt, solution, and slurry prepregging. In the process, fluidized powder is deposited on spread tow bundles and fused to the fibers by radiant heating. Impregnated tows have been produced for preform, weaving, and composite materials applications. Design and operating data correlations were developed for scale up of the process to commercial operation. Bench scale single tow experiments at tow speeds up to 50 cm/sec have demonstrated that the process can be controlled to produce weavable towpreg. Samples were woven and molded into preform material of good quality.

Baucom, Robert M.; Marchello, Joseph M.

1991-01-01

157

Powder magnetoresistance (invited)  

NASA Astrophysics Data System (ADS)

Magnetoresistance observed in pressed powder compacts of half-metallic ferromagnetic oxides is reviewed. The main, isotropic negative magnetoresistance, which exceeds 50% in CrO2 at low temperature, is due to alignment of the the ferromagnetic moments of contiguous ferromagnetic grains. The effect is related to interparticle tunelling and shows hysteresis similar to that of the bulk magnetization. Spin-dependent Coulomb blocade observed in the smallest particles. There is also, an anisotropic magnetoresistance of up to 1% and a high-field increase in conductivity of order 1%/T in the powder compacts.

Coey, J. M. D.

1999-04-01

158

Sugar Substitutes: Aspartame  

MedlinePLUS

... sugar substitute. It is a combination of 2 amino acids, aspartic acid and phenylalanine. It is about 220 ... bodies are unable to metabolize one of the amino acids in aspartame, phenylalanine. Benefits of aspartame Does not ...

159

Substitution of anticonvulsant drugs  

PubMed Central

Changing from branded drugs to generic alternatives, or between different generic formulations, is common practice aiming at reducing health care costs. It has been suggested that antiepileptic drugs (AEDs) should be exempt from substitution because of the potential negative consequences of adverse events and breakthrough seizures. Controlled data are lacking on the risk of substitution. However, retrospective data from large medical claims databases suggest that switching might be associated with increased use of AED and non-AED medications, and health care resources (including hospitalization). In addition, some anecdotal evidence from patients and health care providers’ surveys suggest a potentially negative impact of substitution. Well-controlled data are needed to assess the real risk associated with substitution, allowing health care professionals involved in the care of patients with epilepsy to make informed decisions. This paper reviews currently available literature, based on which the authors suggest that the decision to substitute should be made on an individual basis by the physician and an informed patient. Unendorsed or undisclosed substitution at the pharmacy level should be discouraged.

Steinhoff, Bernhard J; Runge, Uwe; Witte, Otto W; Stefan, Hermann; Hufnagel, Andreas; Mayer, Thomas; Kramer, Gunter

2009-01-01

160

In situ synthesis of silicon-substituted biphasic calcium phosphate and their performance in vitro  

NASA Astrophysics Data System (ADS)

In situ preparation of silicon (Si) substituted biphasic calcium phosphate (BCP) of hydroxyapatite (HAp)/ ?-tricalcium phosphate (?-TCP) were carried out through aqueous co-precipitation method. The concentrations of added silicon were varied with the phosphor in order to obtain constant Ca/(P+Si) ratios of 1.602. X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy were used to characterize the structure of synthesized silicon substituted BCP powders. The characterization revealed that the formation of biphasic mixtures of different HAp/ ?-TCP ratios was dependent on the content of silicon. After immersing in Hanks' balanced salt solution (HBSS) for 1 week, 3 wt% silicon substituted BCP powders were degraded and precipitation started to be formed with small granules consisting of number of flake-like crystal onto the surface of synthesized powders. In the case of 1 wt% silicon substituted BCP powders, the degradation behavior was detected after immersion in HBSS for 3 weeks. On the other hand, silicon unsubtituted BCP powders were not degraded even after that duration. On the basis of these results, silicon substituted BCP is able to develop a new apatite phase on the surface in contact with physiological fluids faster than BCP does. This enhanced reactivity resulted in reduction for the stability of the ?-TCP structure due to SiO4 tetrahedral distortion and disorder at the hydroxyl site when silicon incorporates into BCP.

Song, Chang-Weon; Kim, Tae-Wan; Kim, Dong-Hyun; Jin, Hyeong-Ho; Hwang, Kyu-Hong; Lee, Jong Kook; Park, Hong-Chae; Yoon, Seog-Young

2012-01-01

161

Magnetic powder filled polymers  

Microsoft Academic Search

The composite magnetic materials with commercial polymer matrix along with different magnetic fillers have been studied, with the aim of tailoring their properties. The measured magnetic parameters of the prepared samples have been compared by those calculated using a model in which the magnetic powder particles are surrounded by the thin layer of matrix material

Jozef Slama; Anna Gruskova; Ludovit Keszegh; Mojmir Kollar

1994-01-01

162

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

163

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

164

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

165

On Responsible Black Leadership.  

ERIC Educational Resources Information Center

Black leaders in the United States must unite among themselves and work for the Black community. Black elected officials should know the will of their constituency before taking a particular stance. Finally, Black leaders should ally themselves with international leaders friendly to the cause of American Blacks. (GC)

Farrakhan, Louis

1985-01-01

166

Substitute Valuations: Generation and Structure  

Microsoft Academic Search

Substitute valuations (in some contexts called gross substitute valuations) are promi- nent in combinatorial auction theory. An algorithm is given in this paper for gen- erating a substitute valuation through Monte Carlo simulation. In addition, the geometry of the set of all substitute valuations for a fixed number of goods K is investigated. The set consists of a union of

Bruce Hajek

2007-01-01

167

In situ synthesis of magnesium-substituted biphasic calcium phosphate and in vitro biodegradation  

SciTech Connect

Highlights: ? Mg–BCP were successfully prepared through in situ aqueous co-precipitation method. ? The amount of ?-TCP phase was changed with the magnesium substitution level. ? The substitution of magnesium led to a decrease in the unit cell volume. ? Mg–BCP could be able to develop a new apatite phase on the surface faster than BCP. -- Abstract: In situ preparation of magnesium (Mg) substituted biphasic calcium phosphate (BCP) of hydroxyapatite (HAp)/?-tricalcium phosphate (?-TCP) were carried out through aqueous co-precipitation method. The concentrations of added magnesium were varied with the calcium in order to obtain constant (Ca + Mg)/P ratios of 1.602. X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy were used to characterize the structure of synthesized magnesium substituted BCP powders. The results have shown that substitution of magnesium in the calcium deficient apatites revealed the formation of biphasic mixtures of different HAp/?-TCP ratios after heating at 1000 °C. The ratios of the formation of phase mixtures were dependent on the content of magnesium. After immersing in Hanks’ balanced salt solution (HBSS) for 1 week, 1 wt% magnesium substituted BCP powders were degraded and precipitation started to be formed with small granules consisting of number of flake-like crystal onto the surface of synthesized powders. On the other hand, in the case of pure BCP powders, the formation of new precipitates was detected after immersion in HBSS for 2 weeks. On the basis of these results, magnesium substituted BCP could be able to develop a new apatite phase on the surface in contact with physiological fluids faster than BCP does. In addition, the retention time to produce the new apatite phase in implantation operation for the BCP powder could be controlled by the amount of magnesium substitution.

Kim, Tae-Wan; Lee, Hyeong-Shin; Kim, Dong-Hyun; Jin, Hyeong-Ho [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)] [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Hwang, Kyu-Hong [School of Nano and Advanced Materials, Gyeongsang National University, Jinju, Kyungnam 660-701 (Korea, Republic of)] [School of Nano and Advanced Materials, Gyeongsang National University, Jinju, Kyungnam 660-701 (Korea, Republic of); Lee, Jong Kook [Department of Advanced Materials Engineering, Chosun University, Gwangju 501-759 (Korea, Republic of)] [Department of Advanced Materials Engineering, Chosun University, Gwangju 501-759 (Korea, Republic of); Park, Hong-Chae [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)] [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Yoon, Seog-Young, E-mail: syy3@pusan.ac.kr [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)] [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of)

2012-09-15

168

Black Sea  

NASA Technical Reports Server (NTRS)

The Black Sea in eastern Russia is experiencing an ongoing phytoplankton bloom. This image, the most recent in a series that began in early may, shows the waters to be even more colorful than before. part of the increased brightness may be due to the presence of sun glint , especially in the center of the sea. However, more organisms appear to be present as well, their photosynthetic pigments reflecting different wavelengths of light.This Moderate Resolution Imaging Spectroradiometer (MODIS) image was captured on June 15, 2002.

2002-01-01

169

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

170

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.

Green, Leonard; Freed, Debra E.

1993-01-01

171

Development of Dry Powder Inhalers  

Microsoft Academic Search

Development of dry powder inhalers involves powder recrystallization, formulation, dispersion, delivery, and deposition of the therapeutic agent in different regions of the airways in prophylaxis\\/ treatment\\/ diagnosis of pulmonary and systemic disorders. Conventional powder production by crystallization and milling has many limitations resulting into development of alternative techniques to overcome the problems. In the last decade many patents have been

Mahavir B. Chougule; Bijay K. Padhi; Kaustubh A. Jinturkar; Ambikanandan Misra

2007-01-01

172

Synthesis of boron nitride powders  

Microsoft Academic Search

In the materials science community there is much interest in the development of new, efficient approaches for preparing ceramic powders having properties or performance characteristics not found with powders produced by traditional metallurgical synthesis methods. In this regard, aerosol-based syntheses are finding general acceptance for the preparation of non-metal and metal oxide powders. In contrast, much less effort has been

Dirk Horst Dreissig

2002-01-01

173

Ignition characteristics of plutonium powder  

Microsoft Academic Search

Two fires occurred recently in a vacuum cleaner used to pick up plutonium powder during brushing of plutonium. The plutonium powder was collected by a conventional canister vacuum cleaner passing directly into the clean bag which was changed daily and sent to Building 771 for recovery. Finely divided metal powder is known to be a potential fire and explosion hazard.

Musgrave

1971-01-01

174

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

175

Vacuum powder injector and method of impregnating fiber with powder  

NASA Technical Reports Server (NTRS)

A method and apparatus uniformly impregnate stranded material with dry powder such as low solubility, high melt flow polymer powder to produce, for example, composite prepregs. The stranded material is expanded in an impregnation chamber by an influx of air so that the powder, which may enter through the same inlet as the air, penetrates to the center of the stranded material. The stranded material then is contracted for holding the powder therein. The stranded material and powder may be pulled through the impregnation chamber in the same direction by vacuum. Larger particles of powder which do not fully penetrate the stranded material may be combed into the stranded material and powder which does not impregnate the stranded material may be collected and reused.

Working, Dennis C. (inventor)

1993-01-01

176

Photoacoustic Spectroscopy of BiOCl Photocatalyst Powder  

NASA Astrophysics Data System (ADS)

Photoacoustic spectroscopy (PAS) was used for the first time to investigate the optical properties and photocatalysis reaction of BiOCl powder. The results of PAS measurements showed that the photoacoustic (PA) amplitude increased gradually in the visible light region and the white BiOCl powder became black when the measurements were repeated many times. Further studies showed that the occurrence of ultraviolet (UV) light-induced oxygen vacancies was the reason for the formation of black BiOCl and increasing visible light absorption. PAS also showed that oxygen vacancies only appeared when the white BiOCl powder was irradiated by UV light with a wavelength smaller than the absorption threshold wavelength. The formation of oxygen vacancies under UV irradiation was focused in the initial 0.5 h. Moreover, photochemical reactions of RhB dye absorbed on the BiOCl powder were studied by means of PAS. The results showed that the oxygen vacancy formation and photocatalytic reaction occurred simultaneously under UV excitation.

Chen, Z. J.; Fang, J. W.; Zhang, S. Y.

2014-05-01

177

40 CFR 721.10040 - Substituted acridine naphtha substituted benzamide (generic).  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Substituted acridine naphtha substituted benzamide (generic...Substances § 721.10040 Substituted acridine naphtha substituted benzamide (generic...identified generically as a substituted acridine naphtha substituted benzamide...

2009-07-01

178

40 CFR 721.10040 - Substituted acridine naphtha substituted benzamide (generic).  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Substituted acridine naphtha substituted benzamide (generic...Substances § 721.10040 Substituted acridine naphtha substituted benzamide (generic...identified generically as a substituted acridine naphtha substituted benzamide...

2010-07-01

179

40 CFR 721.10040 - Substituted acridine naphtha substituted benzamide (generic).  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Substituted acridine naphtha substituted benzamide (generic...Substances § 721.10040 Substituted acridine naphtha substituted benzamide (generic...identified generically as a substituted acridine naphtha substituted benzamide...

2013-07-01

180

Magnetic and Magnetoelastic Properties of Chromium Substituted Cobalt Ferrite  

Microsoft Academic Search

In the present study, A series of polycrystalline chromium-substituted cobalt ferrite samples with compositions of CoCrxFe2-xO4 were prepared by standard powder ceramic techniques. The microstructure and final composition of the samples were characterized using a scanning electron microscope with energy-dispersive X-ray spectroscopy (EDX). The crystal structure of the samples was determined by X-ray diffractometry to be cubic spinel. Curie temperature,

C. Lo; P. Matlage; Y. Melikhov; J. Snyder; S. Song; D. Jiles

2006-01-01

181

Bread quality of frozen dough substituted with modified tapioca starches  

Microsoft Academic Search

Rheological properties of dough and bread quality of frozen dough-bread containing 18.4% of hydroxypropylated (HTS), acetylated\\u000a (ATS), and phosphorylated cross-linked (PTS) tapioca starch with different degrees of modification and 1.6% of dried powdered\\u000a gluten were compared to the same amount of native tapioca starch (NTS) or wheat flour-bread. Doughs substituted with native\\u000a or modified tapioca starches had the same mixing

Megumi Miyazaki; Tomoko Maeda; Naofumi Morita

2008-01-01

182

High temperature magnetic properties of mechanically alloyed Fe–Zr powder  

Microsoft Academic Search

We report the preparation and characterization of amorphous\\/non-equilibrium solid solution Fe100?xZrx (x=20–35) alloys by mechanical alloying process. The microstructure and magnetic properties of milled powders have been studied as a function of Zr substitution. The effective magnetic moment of as-milled powders decreases as concentration of Zr is increased. Thermomagnetization measurements confirmed that the Fe80Zr20 sample exhibits two clear magnetic phase

Debabrata Mishra; A. Perumal; A. Srinivasan

2008-01-01

183

Ultrafine hardmetals prepared by WC–10 wt.%Co composite powder  

Microsoft Academic Search

Ultrafine tungsten carbide–cobalt (WC–10wt.%Co) composite powder was synthesized via spray-drying and direct reduction and carburization process in vacuum, which includes precursor preparation by spray-drying of a suspension of ammonium metatungstate (AMT) and cobalt carbonate (CoCO3), calcination to evaporate volatile components, formation of tungsten–cobalt mixed oxide powder (CoWO4\\/WO3), ball-milling with carbon black, and subsequent direct reduction and carburization reaction in vacuum.

Zhen Xiong; Gangqin Shao; Xiaoliang Shi; Xinglong Duan; Li Yan

2008-01-01

184

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

185

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.

186

The Age of Substitutability  

ERIC Educational Resources Information Center

Dwindling mineral resources might cause a shift from nonrenewable resources to renewable resources and inexhaustible elements such as iron and aluminum. Alternative energy sources such as breeder, fusion, solar, and geothermal power must be developed for production and recycling of materials. Substitution and, hence, living standards ultimately…

Goeller, H. E.; Weinberg, Alvin M.

1976-01-01

187

Performing Substitute Teaching  

ERIC Educational Resources Information Center

Formal education is both a right and an obligation bestowed on young people in most all nations of the world. Teachers (adults) and students (youth) form a co-present dyadic contract that must be maintained within the classroom. Substitute teachers fill a role in sustaining the integrity of this teacher-student link, whenever teachers are absent.…

Bletzer, Keith V.

2010-01-01

188

40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...  

Code of Federal Regulations, 2010 CFR

...substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo substituted benzenesulfonic acid copper compound (generic). 721.10126 Section 721.10126 Protection...

2010-07-01

189

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

Microsoft Academic Search

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

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

1994-01-01

190

Infrared studies of apatites. I. Vibrational assignments for calcium, strontium, and barium hydroxyapatities utilizing isotopic substitution  

Microsoft Academic Search

The infrared spectra of powdered calcium hydroxyapatite isotopically ; substituted with D, ¹⁸O, ⁴⁴Ca, and ⁴⁸Ca and infrared spectra of ; powdered strontium and barium hydroxyapatites and their deuterated analogs are ; reported at 48 and - 185 deg in the 4000-200cm-¹ region. Band ; assignments, based on isotopic frequency shifts, band intensity, band temperature ; dependency, and comparisons between

B. O. Fowler

1974-01-01

191

Study on second harmonic generation of 9-benzylidene-substituted-10-methyl-9,10-dihydroacridines  

Microsoft Academic Search

Eight 9-benzylidene-substituted-10-methyl-9,10-dihydroacridine derivatives were synthesized from acridine as starting material and were characterized by 1H-NMR, 13C-NMR, Ms and elemental analysis. The second harmonic generation (SHG) values of these compounds were determined in powder using Nd:YAG as a laser source, as compared with urea powder, and the values of second-order polarizabilities (?xxx), the values of the composite magnitude (?CT?g) of molecular

Hua-Can Song; Rui-Jiang Jin; Xiang-Li Zheng; Bai-Ning Ying

2001-01-01

192

Synthesis and characterization of single-phase silicon-substituted ?-tricalcium phosphate  

Microsoft Academic Search

Silicon-substituted calcium phosphate (CaP) powders with a Ca\\/(P+Si) ratio of 1.50 have been prepared by a wet chemical method, with silicon contents up to 2.16 weight percent (wt%). Sintering for 2h at 1250°C yields single-phase silicon-substituted alpha tricalcium phosphate (Si-?-TCP) for compositions between 0.59 and 1.14wt% silicon. The sintered powders have been characterized with X-ray fluorescence (XRF) spectrometry, X-ray diffraction

Joel W. Reid; Loughlin Tuck; Michael Sayer; Karen Fargo; Jason A. Hendry

2006-01-01

193

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

194

Noncommutative black holes  

NASA Astrophysics Data System (ADS)

We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the "noncommutative" Schwarzschild black hole.

López-Domínguez, J. C.; Obregón, O.; Ramírez, C.; Sabido, M.

2007-11-01

195

Chemical reactions of metal powders with organic and inorganic liquids during ball milling  

NASA Technical Reports Server (NTRS)

Chromium and/or nickel powders were milled in metal chlorides and in organic liquids representative of various functional groups. The powders always reacted with the liquid and became contaminated with elements from them. The milled powders had specific surface areas ranging from 0.14 to 37 sq m/g, and the total contamination with elements from the milling liquid ranged from 0.01 to 56 weight percent. Compounds resulting from substitution, addition, or elimination reactions formed in or from the milling liquid.

Arias, A.

1975-01-01

196

Explicit Substitutions and All That.  

National Technical Information Service (NTIS)

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 pro...

M. Ayala-Rincon C. Munoz

2000-01-01

197

Detection and characterization of smokeless powders with ion mobility spectrometry  

NASA Astrophysics Data System (ADS)

Smokeless Powders are a class of propellants that were developed in the late 19th century to replace black powder; it has been used as an explosive in shotguns, rifles, firearms and many other larger caliber weapons. These propellants can be placed into one of three different classes according to the chemical composition of their primary energetic ingredients. Advance equipment have been designed and used for the detection of explosives devices and compounds potentially energetic. In this research we are developing an analytical methodology to detect different formulation of smokeless powders: Alliant-American Select, Alliant-Bullseye, and Alliant-Red Dot using the ion mobility spectrometry (IMS) technique. We used different surfaces like computer diskettes, CD"s, book covers and plastics to study their adsorption/desorption process. Using micropipettes, we delivered solutions with different amounts of Smokeless Powders from a 1000 ppm solution and deposit it on various types of filters to make a calibration curve. Several amounts of Smokeless Powder were deposited to the different surfaces and collected with filter paper. The samples were desorbed directly from the filter to the instrument inlet port. Subsequently, the percentage of explosive recovered was calculated.

Hernandez, Neiza M.; Rosario, Santa V.; Hernandez, Samuel P.; Mina, Nairmen

2005-05-01

198

Melamine milk powder and infant formula sold in East Africa.  

PubMed

This is the first study proving the existence of melamine in milk powder and infant formula exported to the African market. A total of 49 milk powder batches were collected in Dar-es-Salaam (Tanzania, East Africa), the center of international trade in East Africa, which serves as a commercial bottleneck and shipment hub for sub-Saharan, Central, and East Africa. Two categories of samples were collected between October and December 2008, immediately after the melamine contamination of Chinese products became public: (i) market brands of all international companies supplying the East African market and (ii) illegally sold products from informal channels. Melamine concentration was determined with the AgraQuant Melamine Sensitive Assay. Despite the national import prohibition of Chinese milk products and unlabeled milk powder in Tanzania, 11% (22 of 200) of inspected microretailers sold milk powder on the local black market. Manufacturers could be identified for only 55% (27) of the 49 investigated batches. Six percent (3 of 49) of all samples and 11% (3 of 27) of all international brand name products tested revealed melamine concentrations up to 5.5 mg/kg of milk powder. This amount represents about twice the tolerable daily intake as suggested by the U.S Food and Drug Administration. Based on our study, we can assume that the number of affected children in Africa is substantial. PMID:20828481

Schoder, Dagmar

2010-09-01

199

Factor substitution in nursing homes  

Microsoft Academic Search

This paper studies factor substitution in one important sector: the nursing home industry. Specifically, we measure the extent to which nursing homes substitute materials for labor when labor becomes relatively more expensive. From a policy perspective, factor substitution in this market is important because materials-intensive methods of care are associated with greater risks of morbidity and mortality among nursing home

John Cawley; David C. Grabowski; Richard A. Hirth

2006-01-01

200

Mechanical milling of magnesium powder  

Microsoft Academic Search

The evolution of microstructure during mechanical milling of magnesium powder has been studied. Commercially pure (99.6%, ?325 mesh) magnesium powder was mechanically milled in a modified SPEX 8000 shaker mill in an inert atmosphere. The optical microscopy of the powder in the early stage of milling showed deformation by twinning and re-twinning within the grains developing sub-grain boundaries, which eventually

S Hwang; C Nishimura; P. G McCormick

2001-01-01

201

Plasmasynthesized nano-aluminum powders  

Microsoft Academic Search

The plasma electro-condensation\\u000a process was used to synthesize nano-sized aluminum powders. Adding different\\u000a chemicals modified the physical and chemical properties of these powders.\\u000a To characterize the nano-sized powders, X-ray diffraction, TEM, BET analyses,\\u000a and simultaneous TG\\/DSC analyses were performed. TG\\/DSC analyses revealed\\u000a a dramatic degradation of the aluminum oxide layer after storage of the aluminum\\u000a powder in air for a

Alla Pivkina; D. Ivanov; Yu. Frolov; Svetlana Mudretsova; Anna Nickolskaya; J. Schoonman

2006-01-01

202

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

203

The Black Black Woman and the Black Middle Class.  

ERIC Educational Resources Information Center

Reprint of a 1973 article that describes the discrimination that particularly dark-skinned Black women suffer, especially at the hands of a color-conscious Black middle class. Calls for dark women to look to the African appearance and working-class roots as sources of pride and strength. (GC)

Jeffers, Trellie

1981-01-01

204

Soil Microbial Responses to Potassium-Based Black Liquor from Straw Pulping  

Microsoft Academic Search

Sodium-based black liquor from fiber pulping for papermaking creates challenging waste disposal issues. By substituting NaOH with KOH in the pulping process, the resulting black liquors may be land applied as an environmentally beneficial disposal alternative. Incuba- tion studies examined the effect of KOH-based black liquor on soil pH, electrical conductivity (EC), microbial biomass, CO2 evolution, and soil enzyme activities

C. Xiao; M. Fauci; D. F. Bezdicek; W. T. McKean; W. L. Pan

2006-01-01

205

Mephedrone, “Bubble” and unidentified white powders: the contested identities of synthetic “legal highs”  

Microsoft Academic Search

Purpose – In this fourth paper in a series on emergent drug trends in the UK (2006 ketamine, 2009 MDMA powder\\/crystal, 2010 mephedrone), the authors consider how the pharmacological landscape has changed since substituted cathinones (including mephedrone) were controlled in April 2010 and in particular assess the prevalence of mephedrone in the general night time economy (NTE) and its relationship

Fiona Measham; Karenza Moore; Jeanette Østergaard

2011-01-01

206

Mg-substituted hydroxyapatite nanopowders: Synthesis, thermal stability and sintering behaviour  

Microsoft Academic Search

This paper reports a systematic investigation on Mg-substituted hydroxyapatite (Ca10?xMgx(PO4)6(OH)2) nanopowders produced by precipitation of Ca(NO3)2·4H2O and Mg(NO3)2. The Mg content ranged between 0.6 and 2.4wt%. Semicrystalline Mg-substituted hydroxyapatite powders made up of needle-like nanoparticles were obtained, the specific surface area ranged between 87 and 142m2\\/g. Pure hydroxyapatite nanopowder decomposed around 1000°C. Mg-substituted hydroxyapatites were thermally stable up to 660°C

Ilaria Cacciotti; Alessandra Bianco; Mariangela Lombardi; Laura Montanaro

2009-01-01

207

Investigations of Light Transfer in Powder Bed  

Microsoft Academic Search

At selective laser sintering \\/ melting of powder bodies by laser irradiation it is very important to determine the actual energy deposited in a layer of powder and its distribution over the thickness of the powder bed. By varying the thickness of the powder bed the distribution of absorbed energy over the thickness of the powder bed has been determined.

Chivel Yuri

2011-01-01

208

Stratigraphy and depositional environments of middle member of Minnelusa formation, central Powder River basin, Wyoming  

Microsoft Academic Search

Regional correlations, from the southern to northern Black Hills and across the central Powder River basin to the Bighorn Mountains, serve as the frame work for a depositional model of middle Minnelusa sediments. In the eastern part of the study area, deposition took place in a carbonate sabkha environment. During transgressive periods, most of this region was covered by a

R. J. Desmond; J. R. Steidtmann; D. F. Cardinal

1985-01-01

209

Characterization of used alkaline batteries powder and analysis of zinc recovery by acid leaching  

Microsoft Academic Search

This paper discusses the spent alkaline batteries characterization and leaching stage experiments results with sulfuric acid as leachant, as part of a complex system, involving purification and electrolytic stages, aiming the Zn recovery. After dismantling batteries by mineral processing techniques, the black powder sample produced was submitted to X-ray diffraction and atomic absorption spectrophotometry in order to identify its composition.

Cleusa Cristina Bueno Martha de Souza; Denise Corrêa de Oliveira; Jorge Alberto Soares Tenório

2001-01-01

210

Powder Dyeing Method for Cosmetics.  

National Technical Information Service (NTIS)

A powder dyeing method for cosmetics is described that is characterized in that dyes or pigments are dispersed in water or alcohol, the solution or dispersion is mixed with porous adsorbant such as silicon dioxide or alumina powder and dried, and the drie...

S. Iwao

1974-01-01

211

Ignition characteristics of plutonium powder.  

National Technical Information Service (NTIS)

Two fires occurred recently in a vacuum cleaner used to pick up plutonium powder during brushing of plutonium. The plutonium powder was collected by a conventional canister vacuum cleaner passing directly into the clean bag which was changed daily and sen...

L. E. Musgrave

1971-01-01

212

Electrical conductivity of carbonaceous powders  

Microsoft Academic Search

The present paper deals with the electrical conductivity of a number of carbonaceous powders undergoing a low compaction. It is shown that the contributions to the conductivity of such samples are too numerous and too complex to be solved exactly. Hence, several criteria are proposed in order to quantify the behaviour of moderately compressed powders, and thus derive several useful

A. Celzard; J. F. Marêché; F. Payot; G. Furdin

2002-01-01

213

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

214

Mound powder loader, Mod 1  

SciTech Connect

At the investigation of Sandia Albuquerque, a semiautomatic powder loader was designed and fabricated for pyrotechnics devices. The basic functions of the system were to load a precise, measured amount of powder into a charge holder and to compact the mixture to a specified density. This report documents the history, rationale, design, and performance of the Mod 1 loader.

Gress, A.V. Jr.

1985-08-21

215

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

216

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.

2012-01-01

217

Acoustic Black Holes  

NASA Astrophysics Data System (ADS)

We discuss some general aspects of acoustic black holes. We begin by describing the associated formalism with which acoustic black holes are established, then we show how to model arbitrary geometries by using a de Laval nozzle.

Cardoso, Vitor

2006-02-01

218

Synthesis of boron nitride powders  

NASA Astrophysics Data System (ADS)

In the materials science community there is much interest in the development of new, efficient approaches for preparing ceramic powders having properties or performance characteristics not found with powders produced by traditional metallurgical synthesis methods. In this regard, aerosol-based syntheses are finding general acceptance for the preparation of non-metal and metal oxide powders. In contrast, much less effort has been given to aerosol-type syntheses for non-oxide powders despite potentially useful benefits. This dissertation describes the application of two chemical systems in aerosol assisted vapor phase synthesis (AAVS) for the preparation of spherical morphology boron oxynitride, BNxOy, powders that are subsequently converted to spherical morphology boron nitride in a second nitridation step. Chapter 1 describes the AAVS synthesis of BNxOy powders using a reaction of an aqueous boric acid containing aerosol with ammonia at 1000°C. The effect of reactor tube material, total gas flow rate, ammonia concentration, boric acid concentration, and urea addition to the boric acid aerosol on the percent oxygen composition is described. The resulting BNxOy powders contain significant amounts of oxygen that require replacement in a second stage nitridation reaction at elevated temperature under ammonia. The influences of the reaction temperature profile, crucible geometry and transformation additive on final oxygen composition and powder crystallinity are described. Chapter 2 outlines the formation of BNxOy powders from an AAVS reaction between the boron precursor (MeO)3B and ammonia. The formation of the powders is studied as a function of total gas flow rate and ammonia concentration. In all cases the resulting powders contain lower levels of oxygen compared to powders produced from aqueous boric acid aerosols. The conversion of the BNxOy powders in the second stage nitridation reaction with ammonia is examined as a function of crucible geometry, temperature profile and ammonia flow rate. In support of this process, the molecular reaction between (MeO)3B and NH3 was reexamined. The adduct, (MeO)3B·NH3, was isolated and its molecular structure determined by single crystal X-ray diffraction techniques. The results of these studies provide guidance for more detailed studies that should result in industrial scale synthesis of spherical morphology BN which currently is not formed by standard metallurgical syntheses. This new material has potential applications in several areas including the formation of BN loaded organic polymer composites.

Dreissig, Dirk Horst

2002-09-01

219

21 CFR 520.441 - Chlortetracycline powder.  

Code of Federal Regulations, 2013 CFR

... false Chlortetracycline powder. 520.441 Section 520...441 Chlortetracycline powder. (a) Specifications. Chlortetracycline powder contains not less than...administer this product with milk or milk replacers;...

2013-04-01

220

21 CFR 73.1646 - Bronze powder.  

Code of Federal Regulations, 2010 CFR

...color additive bronze powder is a very fine metallic powder prepared from alloys...virgin electrolytic copper and zinc with small...zinc, tin, and copper content shall be based...weight of the dried powder after being...

2009-04-01

221

21 CFR 73.1646 - Bronze powder.  

Code of Federal Regulations, 2010 CFR

...color additive bronze powder is a very fine metallic powder prepared from alloys...virgin electrolytic copper and zinc with small...zinc, tin, and copper content shall be based...weight of the dried powder after being...

2010-04-01

222

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Copper powder. 73.2647 Section 73.2647...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

2010-04-01

223

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Copper powder. 73.2647 Section 73.2647...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

2009-04-01

224

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Aluminum powder. 73.2645 Section 73.2645 ...Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in identity and...

2013-04-01

225

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Bronze powder. 73.2646 Section 73.2646 ...CERTIFICATION Cosmetics § 73.2646 Bronze powder. (a) Identity and specifications. The color additive bronze powder shall conform in identity and...

2013-04-01

226

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Copper powder. 73.2647 Section 73.2647 ...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity and...

2013-04-01

227

Bicycling black rings  

Microsoft Academic Search

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

Henriette Elvang; Maria J. Rodriguez

2008-01-01

228

Black holes without firewalls  

NASA Astrophysics Data System (ADS)

The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and reemits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of the order of the black hole scrambling time.

Larjo, Klaus; Lowe, David A.; Thorlacius, Larus

2013-05-01

229

Properties of an atomized iron powder  

Microsoft Academic Search

ction Association by atomization of molten EP-612 steel with water under a pressure of 40 atm gauge [2] and two reduced iron powders - Brovary Powder Metallurgy Factory PZh4M2 powder and Hoeganaes NC 100.24 powder, in addition, a similar study was made of specially prepared atomized powders having particle-size distributions corresponding to those of PZh4M2 and NC 100.24 powders. By

A. E. Kushchevskii; A. T. Pekarik; O. S. Nichiporenko; A. B. Medvedovskii

1978-01-01

230

Searching for Black Holes.  

National Technical Information Service (NTIS)

Our UV/VIS work concentrates on black hole X-ray nova. These objects consist of two stars in close orbit, one of which we believe is a black hole - our goal is to SHOW that one is a black hole. In order to reach this goal we carry out observations in the ...

M. Garcia

1998-01-01

231

Black and Gifted.  

ERIC Educational Resources Information Center

The report, based on a conference presentation on the exceptional Black child, includes two papers on potentially gifted and talented Black students. The first, "The Identification and Assessment of Black Gifted/Talented Children in Washington, D.C. Public Schools," (P. Blackshear), traces the evolution of the identification effort over a three…

Blackshear, Patsy Baker; And Others

232

IMAGES OF BLACK AMERICANS  

PubMed Central

Images of Black Americans are becoming remarkably diverse, enabling Barack Obama to defy simple-minded stereotypes and succeed. Understood through the Stereotype Content Model’s demonstrably fundamental trait dimensions of perceived warmth and competence, images of Black Americans show three relevant patterns. Stereotyping by omission allows non-Blacks to accentuate the positive, excluding any lingering negativity but implying it by its absence; specifically, describing Black Americans as gregarious and passionate suggests warmth but ignores competence and implies its lack. Obama’s credentials prevented him from being cast as incompetent, though the experience debate continued. His legendary calm and passionate charisma saved him on the warmth dimension. Social class subtypes for Black Americans differentiate dramatically between low-income Blacks and Black professionals, among both non-Black and Black samples. Obama clearly fit the moderately warm, highly competent Black-professional subtype. Finally, the campaign’s events (and nonevents) allowed voter habituation to overcome non-Blacks’ automatic emotional vigilance to Black Americans.

Fiske, Susan T.; Bergsieker, Hilary B.; Russell, Ann Marie; Williams, Lyle

2013-01-01

233

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

234

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, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic 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 thallium 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); Blaugher, Richard D. (Evergreen, CO)

1995-01-01

235

[Bone substitutes: Classification and concerns].  

PubMed

Autograft is considered as the "gold standard" for bone reconstruction. It provides osteoinductive factors, osteogenic cells, and appropriate osteoconductive scaffold. Donor site morbidity is the main limitation of autograft. Donor disease transmission limits the use of allograft. Synthetic bone substitutes still lack osteoinductive or osteogenic properties. Composite bone substitutes combining synthetic scaffold and biochemical substances initiating proliferation and cell differentiation, and possibly osteogenesis. Bone substitutes and grafts intended for clinical use are listed. PMID:21783214

Chai, F; Raoul, G; Wiss, A; Ferri, J; Hildebrand, H F

2011-09-01

236

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

237

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 tetraalkyl 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. 2 figs.

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

1996-01-02

238

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

239

Method for molding ceramic powders  

DOEpatents

A method for molding ceramic powders comprises forming a slurry mixture including ceramic powder, a dispersant for the metal-containing powder, and a monomer solution. The monomer solution includes at least one multifunctional monomer, a free-radical initiator, and an organic solvent. The slurry mixture is transferred to a mold, and the mold containing the slurry mixture is heated to polymerize and crosslink the monomer and form a firm polymer-solvent gel matrix. The solid product may be removed from the mold and heated to first remove the solvent and subsequently remove the polymer, whereafter the product may be sintered.

Janney, Mark A. (Knoxville, TN)

1990-01-01

240

Method for molding ceramic powders  

DOEpatents

A method for molding ceramic powders comprises forming a slurry mixture including ceramic powder, a dispersant for the metal-containing powder, and a monomer solution. The monomer solution includes at least one multifunctional monomer, a free-radical initiator, and an organic solvent. The slurry mixture is transferred to a mold, and the mold containing the slurry mixture is heated to polymerize and crosslink the monomer and form a firm polymer-solvent gel matrix. The solid product may be removed from the mold and heated to first remove the solvent and subsequently remove the polymer, where after the product may be sintered.

Janney, M.A.

1990-01-16

241

Searching for Black Holes  

NASA Technical Reports Server (NTRS)

In 1995 we proposed to carry out ground-based observations in order to securely identify stellar mass black holes in our galaxy. This type 4 proposal under NASA's UV, Visible, and Gravitational Astrophysics program compliments NASA's space-based research by following up black hole candidates found and studied with space-based observatories, in order to determine if they are indeed black holes. While our primary goal is to securely identify black holes by measuring their masses, a secondary goal is identifying unique visible-range signatures for black holes.

Garica, M.

2001-01-01

242

Magnetized static black Saturn  

SciTech Connect

We present a new static solution to the 5D Einstein-Maxwell equations describing a static black hole surrounded by a nonrotating 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 nonuniqueness of the 5D magnetized static neutral black objects for fixed total mass and Melvin background.

Yazadjiev, Stoytcho S. [Institut fuer Theoretische Physik, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany) and Department of Theoretical Physics, Faculty of Physics, Sofia University, 5 James Bourchier Boulevard, Sofia 1164 (Bulgaria)

2008-06-15

243

Influence of debittered, defatted fenugreek seed powder and flaxseed powder on the rheological characteristics of dough and quality of cookies.  

PubMed

A functional ingredient mix (FIM) comprising debittered and defatted fenugreek seed powder (70%) and flaxseed powder (30%) was used in cookies. Ash, fat and protein, dough development time, resistance to extension and peak viscosity values increased as the level of FIM increased from 10 to 30% in the blend. Beyond 20% of FIM substitution, the quality characteristics of cookies were adversely affected. Use of soya lecithin produced a significant improvement in the overall quality of the cookies with 20% FIM. Linolenic acid and total dietary fiber content of the cookies with 20% FIM and lecithin contained four times the amount of linolenic acid (2.3%) and double the amount of dietary fiber (13.04%) when compared with the control cookies (0.5% and 6.22%) respectively. Surface scanning electron microscopy of cookies with different levels of FIM from 10 to 30% showed that there was a disruption in the matrix. PMID:21250900

Metwal, Nirmala; Jyotsna, R; Jeyarani, T; Venkateswara Rao, G

2011-06-01

244

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

245

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

246

40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...  

Code of Federal Regulations, 2013 CFR

... false Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega...10214 Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega...generically as poly(oxyalkylenediyl),.alpha.-substituted...

2013-07-01

247

Characterization of nanometer tungsten powders  

Microsoft Academic Search

Three types of tungsten powders were prepared by hydrogen reduction of three precursor powders at low temperature, which were used as samples, and were then characterized by Brunauer-Emmer-Teller (BET) method, scanning electron microscopy (SEM), transmission electronic microscopy (TEM), small angle X-ray scattering (SAXS), and field-emission scanning electron microscopy (FESEM) respectively. The results showed that although BET and SEM could not

Huiqian LI; Tao LIN; Huiping SHAO; Chengyi WU; Zhimeng GUO; Ji LUO

2008-01-01

248

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

249

Preparation of zirconium boride powder  

Microsoft Academic Search

An intermediate reaction in the synthesis of ZrBâ powder by the reduction of ZrOâ with BâC and carbon was confirmed through both thermodynamical calculation and experimental results. Because the intermediate product BâOâ was volatile, excess boron should be added to compensate for the boron loss in order to prepare high-purity ZrBâ powder. The synthesis temperatures of the intermediate reaction and

Hong Zhao; Yu He; Zongzhe Jin

1995-01-01

250

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

251

Method for Production of Powders  

NASA Technical Reports Server (NTRS)

Apparatus and method are disclosed for producing oxides of metals and of metal alloys. The metal or alloy is placed in an oxygen atmosphere in a combustion chamber and ignited. Products of the combustion include one or more oxides of the metal or alloy in powdered form. In one embodiment of the invention a feeder is provided whereby material to be oxidized by combustion can be achieved into a combustion chamber continuously. A product remover receives the powder product of the combustion.

Stoltzfus, Joel M. (Inventor); Sircar, Subhasish (Inventor)

1997-01-01

252

Powder metal technologies and applications  

Microsoft Academic Search

This volume is: (1) a completely updated and expanded edition in all areas of powder production, sampling, characterization, shaping, consolidation, sintering, quality control, machining, heat treating, and P\\/M applications; (2) single source for practical engineering information on sintering practices, tool design, P\\/M metallography, dimensional control, part design, powders, binders, lubricants, and the processing, properties, and performance of P\\/M materials in

W. B. Eisen; B. L. Ferguson; R. M. German; R. Iacocca; P. W. Lee; D. Madan; K. Moyer; H. Sanderow; Y. Trudel

1998-01-01

253

Evaluation of new porous ?-tri-calcium phosphate ceramic as bone substitute in goat model  

Microsoft Academic Search

The present study was carried out to evaluate the porous ?-tri-calcium phosphate (TCP) (prepared by aqueous solution combustion technique) as bone substitute and compared with normal healing in 12 adult Black Bengal goats on the basis of clinical and radiographic findings, histological studies, oxytetracycline labeling, angiography studies (on day 90). Bone defects created in the diaphysis of radius were left

Samit K. Nandi; Samir K. Ghosh; Biswanath Kundu; Dipak K. De; Debabrata Basu

2008-01-01

254

Powder collection apparatus/method  

DOEpatents

Device for separating and collecting ultrafine atomized powder from the gas stream of a gas atomizing apparatus comprises a housing having an interior wall oriented at an angle relative to horizontal so as to form a downwardly converging, conical expansion chamber, an inlet conduit communicated to the expansion chamber proximate an upper region thereof for receiving the gas stream, and an outlet proximate a lower region of the expansion chamber. The inlet conduit is oriented at a compound inclined angle (with respect to horizontal) selected to promote separation and collection of powder from the gas stream in the expansion chamber. The compound angle comprises a first entrance angle that is greater than the angle of repose of the powder on the housing interior wall such that any powder accumulation in the inlet conduit tends to flow down the wall toward the outlet. The second angle is selected generally equal to the angle of the housing interior wall measured from the same horizontal plane so as to direct the gas stream into the expansion chamber generally tangent to the housing interior wall to establish a downward swirling gas stream flow in the expansion chamber. A powder collection container is communicated to the outlet of the expansion chamber to collect the powder for further processing. 4 figures.

Anderson, I.E.; Terpstra, R.L.; Moore, J.A.

1994-01-11

255

Iridium-Catalyzed Allylic Substitution  

Microsoft Academic Search

Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is generated by a base-induced

John F. Hartwig; Mark J. Pouy

2011-01-01

256

Dynamical properties of logical substitutions  

Microsoft Academic Search

This is an expository paper on the dynamical properties of substitutions in\\u000apropositional many-valued logics. We identify substitutions with endomorphisms\\u000aof free algebras, and we study their actions on the dual spectral spaces.

Giovanni Panti

2006-01-01

257

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

PubMed Central

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 (CO3-HA) with ?5?wt% substituted carbonate content (sample 7.5CO3-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 7.5CO3-HA. For silicate-substituted hydroxyapatite (SiO4-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 SiO4-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.

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

2013-01-01

258

Structural and electromagnetic characteristics of substituted strontium hexaferrite nanoparticles  

Microsoft Academic Search

Substituted strontium ferrite SrFe9(Mn0.5Co0.5Zr)3\\/2O19 has been prepared from sol–gel method. X-ray diffraction (XRD), transmission electron microscope (TEM) and vector network analyzer, were used to analyze the structure and dynamic magnetic properties. Powders of sample show a hexagonal fine platelet structure and narrow particle size distribution. Based on microwave measurement on reflectivity, SrFe9(Mn0.5Co0.5Zr)3\\/2O19 may be a good candidate for electromagnetic compatibility

Ali Ghasemi; Akimitsu Morisako

2008-01-01

259

Composite copper\\/stainless steel coated powders  

Microsoft Academic Search

The present research work concerns the development of new composites based on austenitic stainless steel (SS) or copper (Cu) microsized powders coated with thin nanostructured layers of copper or stainless steels, respectively. A home-manufactured magnetron sputtering system equipped with a powder vibration device was used to coat the powders. A detailed analysis of the coated copper or stainless steel powders

Mariana Matos; José M. Castanho; Maria T. Vieira

2009-01-01

260

21 CFR 73.1646 - Bronze powder.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Bronze powder. 73.1646 Section 73.1646 Food...CERTIFICATION Drugs § 73.1646 Bronze powder. (a) Identity. (1) The color additive bronze powder is a very fine metallic powder...

2013-04-01

261

How Do Substitute Teachers Substitute? An Empirical Study of Substitute-Teacher Labor Supply  

ERIC Educational Resources Information Center

This paper examines the daily labor supply of a potentially important, but often overlooked, source of instruction in U.S. public schools: substitute teachers. I estimate a sequential binary-choice model of substitute teachers' job-offer acceptance decisions using data on job offers made by a randomized automated calling system. Importantly, this…

Gershenson, Seth

2012-01-01

262

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

Code of Federal Regulations, 2010 CFR

... 2009-07-01 2009-07-01 false Substituted phenyl azo substituted sulfocarbopolycle, sodium salt. 721.9545...Specific Chemical Substances § 721.9545 Substituted phenyl azo substituted sulfocarbopolycle, sodium...

2009-07-01

263

Production and consumption of aluminum powders (review)  

Microsoft Academic Search

UDC 621.762 The prod, ration of powder products of aluminum and its alloys (medium and very fine powders, pastes, granules) is one of the fastest growing areas of international aluminum metallurgy. In terms of volume of production, the output of aluminum powders and pastes is second after iron powders. World pro~iuction of powder aluminum products annually during the period 1993-1996

O. S. Nichiporenko

1997-01-01

264

Quantization of Black Holes  

NASA Astrophysics Data System (ADS)

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 also be derived from an ansatz of quantized entropy ? S = 4? k ? R/{{-{? }}}, 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.

He, Xiao-Gang; Ma, Bo-Qiang

265

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

266

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

267

40 CFR 721.5867 - Substituted phenol.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Substituted phenol. 721.5867 Section 721.5867 ...Substances § 721.5867 Substituted phenol. (a) Chemical substance and significant...substance generically identified as substituted phenol (PMNs P-89-1125,...

2013-07-01

268

40 CFR 721.9488 - Substituted resorcinols.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted resorcinols. 721.9488 Section 721.9488...Substances § 721.9488 Substituted resorcinols. (a) Chemical substance and significant...identified generically as substituted resorcinols (PMNs P-95-1103,...

2010-07-01

269

40 CFR 721.9488 - Substituted resorcinols.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Substituted resorcinols. 721.9488 Section 721.9488...Substances § 721.9488 Substituted resorcinols. (a) Chemical substance and significant...identified generically as substituted resorcinols (PMNs P-95-1103,...

2009-07-01

270

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.

271

Teaching the Black Rhetoric Course.  

ERIC Educational Resources Information Center

Until the late 1960s, rhetoric instruction in the United States ignored forms of rhetoric used by black Americans, although black rhetoric has existed in the United States for as long as black people have lived there. A course in black rhetoric must acknowledge the persuasive intent of all rhetoric, but note at the same time that black rhetoric…

Cummings, Melbourne S.

272

Black Holes in String Theory  

Microsoft Academic Search

This thesis is devoted to trying to find a microscopic quantum description of black holes. We consider black holes in string theory which is a quantum theory of gravity. We find that the ``area law'' black hole entropy for extremal and near-extremal charged black holes arises from counting microscopic configurations. We study black holes in five and four spacetime dimensions.

Juan Mart n Maldacena

1996-01-01

273

Hubble Hunts Black Holes  

NSDL National Science Digital Library

This interactive, online module provides students the opportunity to explore actual Hubble images and the tools used to hunt for black holes. By completing this activity, students learn about the technology required to confirm the existence of black holes. Students may complete this activity independently or in small groups. Detailed teacher pages, identified as Teaching Tips on the title page, provide science background information, lesson plan ideas, related resources, and alignment with national education standards. This activity is a subsection of "Is a Black Hole Really A Hole?" It is within the online exploration No Escape: The Truth about Black Holes, available on the Amazing Space website.

274

Black holes in review  

NASA Astrophysics Data System (ADS)

Black holes are the theoretical space-time warps where gravitational forces are so intense that all matter and energy—even light—are effectively trapped and absorbed. So far, there has been no direct evidence, no positive acceptable proof or observation, of black holes, but their incredibly unique properties have been used by modern-day astronomers to provide explanations for many unanswered questions, including those associated with the ‘big bang,’ from which the universe is residue.Black hole theory has provided heady excitement in the past several years as its unique aspects have emerged. For example, the Hawkings radiation effect was the result of an impressive application of quantum theory to objects of astronomic dimensions that demonstrated that black holes could be the origin of the observed X ray emissions from globular star clusters. However, as the fascination with black holes continues to grow, with new results that test the laws of physics against black hole theory, physicists are beginning to cast doubt on their validity. According to a recent report, ‘… participants at an International Astronomical Union meeting in Bandung, Indonesia, presented several papers indicating the growth of something of a backlash against the black hole as an astrophysical panacea’ (New Scientist, Jan. 14, 1982). Nonetheless, as long as black holes are in fashion, theorists continue to derive interesting physical models, such as ‘On being lowered into a black hole,’ by Newcastle-upon-Tyne University physicist Paul Davies (New Scientist, op. cit.).

Bell, Peter M.

275

Black hole Berry phase.  

PubMed

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. PMID:19905501

de Boer, Jan; Papadodimas, Kyriakos; Verlinde, Erik

2009-09-25

276

Black hole statistics  

SciTech Connect

The quantum statistics of charged, extremal black holes is investigated beginning with the hypothesis that the quantum state is a functional on the space of closed three-geometries, with each black hole connected to an oppositely charged black hole through a spatial wormhole. From this starting point a simple argument is given that a collection of extremal black holes obeys neither Bose nor Fermi statistics. Rather, they obey an exotic variety of particle statistics known as infinite statistics'' which resembles that of distinguishable particles and is realized by a [ital q] deformation of the quantum commutation relations.

Strominger, A. (Institute for Theoretical Physics and Department of Physics, University of California (enSanta Barbara, Santa Barbara, California 93106 (United States)))

1993-11-22

277

[Ileal bladder substitute].  

PubMed

The history of urinary diversion in general began in 1852 and started right away with continent diversion, i.e., ureterosigmoidostomy. Anastomosing an intestinal reservoir to the urethra was proposed by Tizzoni and Foggi in 1888. They replaced the bladder by an isoperistaltic ileal segment which was interposed between ureters and urethra in a female dog. In 1951 Couvelaire reactivated this idea of an ileal bladder substitute. Retrospectively many disappointing results of urinary diversion were often not caused by insufficient competence of the outlet mechanism, but because the intestinal reservoir maintained its peristaltic properties causing high pressure peaks. The decisive advance in ensuring continence, and thus an improvement in patient comfort, was achieved with the so-called low pressure reservoir. The main characteristics of this reservoir compared to those from intact intestinal segments are the larger diameter, the greater capacity with significantly low pressures, and the uncoordinated contraction of its wall. Transsection of the circular intestinal musculature when performing bladder augmentation had already been published by Rutkowski in 1899, Tasker in 1953, and Giertz in 1957. In 1969, Kock published the first results obtained with an ileal continent fecal reservoir in patients after total proctocolectomy. The significant advantages of interrupting the tubular structure of a reservoir obtained from intestine had been described much earlier. The need for reflux prevention is not the same as in ureterosigmoidostomy conduit or continent diversion. Reflux prevention in neobladders is even less important than in a normal bladder. When using nonrefluxing techniques, the risk of obstruction is at least twice that after direct anastomosis. Kidney function is not impaired by diversion if stenosis is recognized and managed. Patient health status is influenced more by underlying disease than by diversion. Orthotopic reconstruction has passed the test of time. In these patients life is similar to that in individuals with a native lower urinary tract. Until a better solution is devised orthotopic bladder reconstruction remains the best option for patients requiring cystectomy. PMID:18210063

Hautmann, R E

2008-01-01

278

Synthesis and spectral characterization of silver/magnesium co-substituted hydroxyapatite for biomedical applications  

NASA Astrophysics Data System (ADS)

The present work is aimed at the synthesis of antibacterial and bioactive silver/magnesium co-substituted hydroxyapatite (Ag/Mg-HAP) powders. For this purpose, firstly, different concentrations (0.5, 1.5, 2.5 wt.%) of silver substituted HAP (Ag-HAP) powders were prepared by ultrasonic irradiation technique and were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Secondly, magnesium (Mg) is co-substituted as secondary material into Ag-HAP to offset the potential cytotoxicity of Ag, as higher concentration of Ag is toxic. The antibacterial activity of as-synthesized powders was evaluated by Escherichia coli (E. coli) and was found to be effectively high against bacterial colonization. Also, the in vitro cell-material interaction is evaluated with human osteosarcoma MG63 (HOS MG63) cells for cell proliferation. The results showed the evidence of cytotoxic effects of the higher concentration of Ag-HAP characterized by poor cellular viability whereas, Ag/Mg-HAP showed better cell viability indicating that co-substitution of Mg in Ag-HAP effectively offset the negative effects of Ag and improve performance compared with pure HAP. Thus, the as synthesized Ag/Mg-HAP will serve as a better candidate for biomedical applications with good antibacterial property and bone bonding ability.

Gopi, D.; Shinyjoy, E.; Kavitha, L.

2014-06-01

279

Synthesis and spectral characterization of silver/magnesium co-substituted hydroxyapatite for biomedical applications.  

PubMed

The present work is aimed at the synthesis of antibacterial and bioactive silver/magnesium co-substituted hydroxyapatite (Ag/Mg-HAP) powders. For this purpose, firstly, different concentrations (0.5, 1.5, 2.5wt.%) of silver substituted HAP (Ag-HAP) powders were prepared by ultrasonic irradiation technique and were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Secondly, magnesium (Mg) is co-substituted as secondary material into Ag-HAP to offset the potential cytotoxicity of Ag, as higher concentration of Ag is toxic. The antibacterial activity of as-synthesized powders was evaluated by Escherichia coli (E. coli) and was found to be effectively high against bacterial colonization. Also, the in vitro cell-material interaction is evaluated with human osteosarcoma MG63 (HOS MG63) cells for cell proliferation. The results showed the evidence of cytotoxic effects of the higher concentration of Ag-HAP characterized by poor cellular viability whereas, Ag/Mg-HAP showed better cell viability indicating that co-substitution of Mg in Ag-HAP effectively offset the negative effects of Ag and improve performance compared with pure HAP. Thus, the as synthesized Ag/Mg-HAP will serve as a better candidate for biomedical applications with good antibacterial property and bone bonding ability. PMID:24632237

Gopi, D; Shinyjoy, E; Kavitha, L

2014-06-01

280

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

281

Powder metal technologies and applications  

SciTech Connect

This volume is: (1) a completely updated and expanded edition in all areas of powder production, sampling, characterization, shaping, consolidation, sintering, quality control, machining, heat treating, and P/M applications; (2) single source for practical engineering information on sintering practices, tool design, P/M metallography, dimensional control, part design, powders, binders, lubricants, and the processing, properties, and performance of P/M materials in different production technologies and applications; (3) comprehensive coverage of P/M technologies and applications including warm compaction, injection molding, rapid prototyping, thermal spray forming, reactive sintering, and P/M gears, bearings, high-performance parts, composites, machine parts, electric contacts, magnetic materials, metallic foams, hardfacing powders, automotive parts, and more.

Eisen, W.B.; Ferguson, B.L.; German, R.M.; Iacocca, R.; Lee, P.W.; Madan, D.; Moyer, K.; Sanderow, H.; Trudel, Y. [eds.

1998-12-31

282

Method for Manufacturing Aluminum Oxynitride (A1ON) Powder and Other Nitrogen-Containing Powders.  

National Technical Information Service (NTIS)

A method of preparing substantially homogeneous aluminum oxynitride powder and other nitrogen-containing powders is provided. Particularly with respect to the AlON powder, the method comprises the steps of milling a mixture of aluminum and aluminum oxide ...

W. Miao

2002-01-01

283

Preclinical evaluation of skin substitutes.  

PubMed

The important requirements of a skin substitute such as water vapour permeability, adherence to the excised wound surface, oxygen permeability, mechanical properties, impermeability to micro-organisms and exudate soaking capacity have been highlighted. Two commercial synthetic skin substitutes, Bioclusive and Geliperm, have been used to establish the preclinical assessment procedures for skin substitutes. Two in vitro techniques, the 'Water Cup' and the 'Inverted Cup,' and two in vivo methods involving a 'Ventilated Hygrometer Chamber' system and an Evaporimeter have been employed to assess and compare the water vapour permeability of the skin substitutes under controlled conditions. An Evaporimeter, which is very simple to operate, provides more accurate results. A simple test has been designed to evaluate the early adherence of the skin substitutes to the excised wound surface of rats. The pulling force and the peeling force required to remove the membrane from the wound surface have been measured and these forces have been found to depend upon the composition of the membrane. An oxygen permeability cell has been fabricated which measures the dissolved oxygen permeability of the skin substitutes. The detection of oxygen is based on the electrocatalytic reduction of oxygen at the surface of a noble metal. The tensile properties of the skin substitutes have been measured by an International Standard procedure and both the skin prostheses are associated with some drawbacks. An in vitro method of testing the microbial permeability of the skin substitutes has been designed which simulates an oozing colonized wound that a skin substitute faces in cases of septicaemia. Both the test materials were impermeable to both bacteria and fungi and will provide an effective barrier. The effectiveness of the skin substitutes to absorb wound exudate from the wound surface has been evaluated by soaking the pieces of the membranes in water, plasma and serum and observing their weight gain. The soaking capacity depends upon the composition and nature of the material. The procedures developed have been employed to evaluate a hydrogel type synthetic skin substitute recently formulated in our laboratory. PMID:2275766

Nangia, A; Hung, C T

1990-10-01

284

Iridium-Catalyzed Allylic Substitution  

Microsoft Academic Search

\\u000a \\u000a Abstract  Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles\\u000a at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand\\u000a possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is\\u000a generated by a base-induced

John F. Hartwig; Mark J. Pouy

285

Preparation and investigation of magnetic properties of MnNiTi-substituted strontium hexaferrite nanoparticles  

NASA Astrophysics Data System (ADS)

A series of M-type strontium hexaferrite powders with substitution of Mn 2+, Ni 2+ and Ti 4+ ions for Fe 3+ ions according to the formula SrFe 9(Mn 0.5- xNi xTi 0.5) 3O 19, where x ranges from 0 to 0.5 with a step of 0.1, has been prepared via the conventional ceramic method. In order to get nanoparticles, the obtained powders were milled in a high energy SPEX mill for 1 h. XRD investigations of the unmilled and milled powders show that the prepared samples are all single phase hexaferrite. Lattice parameters and mean crystallite sizes of the powders were determined from the XRD data and Scherrer's formula. Transmission electron microscope (TEM) was used to analyze their structures. Room temperature magnetizations and coercivities of the samples in a magnetic field of 15 kOe have been determined from the hysteresis loops. It was found that magnetizations of the milled samples were smaller than the magnetization of the unmilled samples. This decrease, based on core-shell model, has been attributed to the presence of a magnetically dead layer on the particles' surface of the milled powders. In addition, the magnetizations of the milled samples decrease with the increase in x value. This decrease has been discussed according to site occupation of the substituted cations on the sublattices. The discussion also supports the increase of lattice parameters and the decrease of Curie temperature as x increases.

Mozaffari, M.; Arab, A.; Yousefi, M. H.; Amighian, J.

2010-09-01

286

Dyscravia: voicing substitution dysgraphia.  

PubMed

We report a new type of dysgraphia, which we term dyscravia. The main error type in dyscravia is substitution of the target letter with a letter that differs only with respect to the voicing feature, such as writing "coat" for "goat", and "vagd" for "fact". Two Hebrew-speaking individuals with acquired dyscravia are reported, TG, a man aged 31, and BG, a woman aged 66. Both had surface dysgraphia in addition to their dyscravia. To describe dyscravia in detail, and to explore the rate and types of errors made in spelling, we administered tests of writing to dictation, written naming, and oral spelling. In writing to dictation, TG made voicing errors on 38% of the words, and BG made 17% voicing errors. Voicing errors also occurred in nonword writing (43% for TG, 56% for BG). The writing performance and the variables that influenced the participants' spelling, as well as the results of the auditory discrimination and repetition tasks indicated that their dyscravia did not result from a deficit in auditory processing, the graphemic buffer, the phonological output lexicon, the phonological output buffer, or the allographic stage. The locus of the deficit is the phoneme-to-grapheme conversion, in a function specialized in the conversion of phonemes' voicing feature into graphemes. Because these participants had surface dysgraphia and were forced to write via the sublexical route, the deficit in voicing was evident in their writing of both words and nonwords. We further examined whether the participants also evinced parallel errors in reading. TG had a selective voicing deficit in writing, and did not show any voicing errors in reading, whereas BG had voicing errors also in the reading of nonwords (i.e., she had dyslegzia in addition to dyscravia). The dissociation TG demonstrated indicated that the voicing feature conversion is separate for reading and writing, and can be impaired selectively in writing. BG's dyslegzia indicates that the grapheme-to-phoneme conversion also includes a function that is sensitive to phonological features such as voicing. Thus the main conclusion of this study is that a separate function of voicing feature conversion exists in the phoneme-to-grapheme conversion route, which may be selectively impaired without deficits in other functions of the conversion route, and without a parallel deficit in reading. PMID:20298704

Gvion, Aviah; Friedmann, Naama

2010-06-01

287

Regular black holes and black universes  

NASA Astrophysics Data System (ADS)

We give a comparative description of different types of regular static, spherically symmetric black holes (BHs) and discuss in more detail their particular type, which we suggest to call black universes. The latter have a Schwarzschild-like causal structure, but inside the horizon there is an expanding Kantowski Sachs universe and a de Sitter infinity instead of a singularity. Thus a hypothetic BH explorer gets a chance to survive. Solutions of this kind are naturally obtained if one considers static, spherically symmetric distributions of various (but not all) kinds of phantom matter whose existence is favoured by cosmological observations. It also looks possible that our Universe has originated from phantom-dominated collapse in another universe and underwent isotropization after crossing the horizon. An explicit example of a black-universe solution with positive Schwarzschild mass is discussed.

Bronnikov, K. A.; Dehnen, H.; Melnikov, V. N.

2007-07-01

288

Consumer talcums and powders: mineral and chemical characterization.  

PubMed

Representative consumer talcums and powders, including 20 body powders, baby powders, facial talcums, and also one pharmaceutical talc, were analyzed to determine their mineralogical and chemical composition. Where known, all were formulated prior to 1973. Of the 20 products 10 contained detectable amounts of tremolite and anthophyllite, principally asbestiform, while some also contained fragmented forms of these minerals. The amounts ranged from tenths of a percent to over 14% by weight; two contained detectable amounts of chrysotile asbestos fiber. Eight contained quartz, seven ranging from 2 to 5%, with one as high as 35%. The analyses showed that the consumer products examined were rarely the pure mineral talc, but rather were mixtures of various minerals; some samples consisted of three to five minerals, only one of which was talc. Other common mineral phases included chlorite, platy serpentine, pyrophyllitem mica, and carbonate minerals. Kaolin additive was identified in two products. The single pharmaceutical talc examined contained only a trace amount of quartz. The chemical composition of these products, including both major oxide and trace element content, correlated with their mineral components. Four samples contained substantial concentrations of nickel, cobalt, and chromium, suggesting latice substitution or the presence of trace mineral phases. Geological provenance of the talcs may be ascertained on the basis of chemistry. Possible adverse health effects from intermittent use of these products, especially those that contain asbestiform and fragmented anthophyllite and tremolite, chrysotile, quartz, and trace metals, are presently unknown and warrnat evaluation. PMID:1011287

Rohl, A N; Langer, A M; Selikoff, I J; Tordini, A; Klimentidis, R; Bowes, D R; Skinner, D L

1976-11-01

289

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

290

Perspectives: Black Holes.  

National Technical Information Service (NTIS)

When asked to discuss Cyg XR-1, E. E. Salpeter once concluded, 'A black hole in Cyg X(R)-1 is the most conservative hypothesis.' Recent observations now make it likely that a black hole in Cyg XR-1 is the only hypothesis tenable. Chandrasekhar first showe...

J. F. Dolan

2001-01-01

291

Cytotoxicity of Platinum Black  

Microsoft Academic Search

Platinum black is a coating material for neural electrodes which has the potential to lower the phase-boundary impedance of the electrode-tissue interface dramatically. Depo- siting platinum black by means of electro- plating involves the use of the toxic heavy metal lead as an electrolyte ingredient. Using surface analytical methods, we could not exclude the possibility that traces of lead were

Schuettler M; Doerge T; Wien SL; Becker S; Staiger A; Hanauer M; Kammer S; Stieglitz T

292

Luminescence of black silicon  

Microsoft Academic Search

Room temperature visible and near-infrared photoluminescence from black silicon has been observed. The black silicon is manufactured by shining femtosecond laser pulses on silicon wafers in air, which were later annealed in vacuum. The photoluminescence is quenched above 120 K due to thermalization and competing nonradiative recombination of the carriers. The photoluminescence intensity at 10K depends sublinearly on the excitation

Ali Serpengüzel; Adnan Kurt; Ibrahim Inanç; James E. Cary; Eric Mazur

2008-01-01

293

Notable Black Women.  

ERIC Educational Resources Information Center

Readings, activities, and teaching strategies for a secondary unit on black women are included in this teacher handbook. Instructional material is divided into four sections. Following a note on the use of the booklet, section 1 consists of 24 two-page biographies of black women, including Selma Burke, Lena Horne, Leontyne Price, Charlayne…

Ellin, Nancy

294

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

295

Black Youth Unemployment Problem.  

National Technical Information Service (NTIS)

The employment rate for black youth, which declined by 50% since 1950, is about half of the employment rate for white youth. The report explores the hypothesis that job decentralization and housing segregation, has resulted in reduced job access for black...

K. R. Ihlanfeldt D. L. Sjoquist

1989-01-01

296

Black History Speech  

ERIC Educational Resources Information Center

The author argues in this speech that one cannot expect students in the school system to know and understand the genius of Black history if the curriculum is Eurocentric, which is a residue of racism. He states that his comments are designed for the enlightenment of those who suffer from a school system that "hypocritically manipulates Black…

Noldon, Carl

2007-01-01

297

Black Boycott: Gainsville, Florida  

ERIC Educational Resources Information Center

A case study of the events precipitating a black student boycott in 1969 in Gainesville, Flordia, when school board manuevering to avoid school integration led to the threatened closing of Lincoln High School, a reputable black community school. Also described are the subsequent transformations of Lincoln into a vocational-technical school and…

White, Arthur O.

1975-01-01

298

On black hole attrition  

Microsoft Academic Search

Two processes of black hole attrition are presented: a microscopic friction process by pair creation and a macroscopic friction process due to energy extraction through electromagnetic fields. It is found that the electromagnetic field of a Kerr-Newman black hole can never be larger than 2 times 10 to 12th G because of vacuum polarization. In a discharge due to vacuum

Rcmo Ruffini

1975-01-01

299

Rotating hairy black holes.  

PubMed

We construct stationary black-hole solutions in SU(2) Einstein-Yang-Mills theory which carry angular momentum and electric charge. Possessing nontrivial non-Abelian magnetic fields outside their regular event horizon, they represent nonperturbative rotating hairy black holes. PMID:11329304

Kleihaus, B; Kunz, J

2001-04-23

300

Synthesis and crystal chemical evolution of fresnoite powders  

SciTech Connect

(Ba,Sr){sub 2}TiSi{sub 2}O{sub 8} fresnoite powders were prepared via a Pechini process in which citric acid and ethylene glycol were used as complexing agents. The resulting gel contained a homogeneous distribution of the metal ions that suppressed the formation of (Ba,Sr)TiO{sub 3} perovskite as a secondary phase during calcination. Phase development was examined as by isochronal and isothermal reaction analysis. A combination of thermo- and differential gravimetric analysis (TGA-DGA), quantitative X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed that calcination at 900 Degree-Sign C/12 h yielded finely crystalline ({approx}70 nm) Ba{sub 2}TiSi{sub 2}O{sub 8} (BTS) and Sr{sub 2}TiSi{sub 2}O{sub 8} (STS). The endmembers and compositional intermediates crystallized directly from the Pechini resin and indirectly through reaction of (Ba,Sr)CO{sub 3}, (Ba,Sr)TiO{sub 3} and a silica-rich glass intermediates. This new method for preparing fresnoite yields materials suitable for consolidation as dense monolithic dielectrics or for use as high surface area catalytic powders. - Graphical abstract: The Pechini synthesis of (Ba, Sr){sub 2}TiSi{sub 2}O{sub 8} titano-silicate fresnoites delivers finely divided precursors for applications as diverse as solid electrolytes and photocatalysis that exploit the unique Ti-O and Si-O bonding and structural morphology of these materials. Highlights: Black-Right-Pointing-Pointer A Pechini method for synthesizing (Ba,Sr){sub 2}TiSi{sub 2}O{sub 8} fresnoites is demonstrated. Black-Right-Pointing-Pointer The method minimizes a persistent glassy intermediate phase. Black-Right-Pointing-Pointer The Pechini process is generally applicable for tailoring fresnoites as functional materials.

Wong, Chui L., E-mail: wong0233@e.ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Madhavi, S. [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Phonthammachai, N. [Institute of Materials Science and Engineering, 3 Research Link, Singapore 117602 (Singapore); White, Timothy J., E-mail: tjwhite@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Centre for Advanced Microscopy, Australian National University, RN Robertson Building, Sullivan's Creek Road, Canberra, 0200 ACT (Australia)

2012-03-15

301

Preparation and investigation of magnetic properties of MnNiTi-substituted strontium hexaferrite nanoparticles  

Microsoft Academic Search

A series of M-type strontium hexaferrite powders with substitution of Mn2+, Ni2+ and Ti4+ ions for Fe3+ ions according to the formula SrFe9(Mn0.5?xNixTi0.5)3O19, where x ranges from 0 to 0.5 with a step of 0.1, has been prepared via the conventional ceramic method. In order to get nanoparticles, the obtained powders were milled in a high energy SPEX mill for

M. Mozaffari; A. Arab; M. H. Yousefi; J. Amighian

2010-01-01

302

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

303

Black hole peregrinations  

NASA Astrophysics Data System (ADS)

We consider the evaporation of a black hole of initial mass Mi, as monitored by observers who measure its position, mass, and momentum from its asymptotic gravitational field at a distance of order ˜Mi^2 in Planck units. As the black hole evaporates, each quanta of Hawking radiation will carry away some spatial momentum and will cause a slight recoil of the black hole. The net effect of this is a spreading of the black hole's wavefunction, first analyzed by Don Page in 1980. There are corresponding fluctuations in the asymptotically measured mass. We argue based on simple models that at the end of the evaporation process the black hole is spread out over a region of size ˜Mi^2 in both space and time. This effect complicates the usual sharp arguments for the information loss paradox, and seems to lead to a slight easing of the paradox.

Flanagan, Eanna

2006-04-01

304

American Black Duck  

USGS Publications Warehouse

A brief summary of the annual cycle of the American Black duck (Anas rubripes) is presented. The history of the American black duck population is tracked by the Mid-Winter Index (MWI) and related to annual harvest. Previous to effective restrictions in the United States in 1982 and later in Canada, the MWI was declining significantly at about 4% annually. Since restrictions were established the black duck population has stabilized, but to reach the goal of 260,000 wintering black ducks in the Atlantic Flyway continued or even more restrictions will be necessary. If the number of breeding pairs can be increased from current levels the black duck population is expected to increase.

Longcore, J.R.; Clugston, D.A.

1998-01-01

305

Pore formation in atomized powders  

Microsoft Academic Search

Experiments have demonstrated that contamination of an alloy with argon in the manufacture of an atomized powder takes place during two stages of the production process: during contact between argon and the melt in the furnace and during atomization. Contamination during the first stage is characteristic of centrifugal atomization, and during both stages, of gas atomization. The porosity of particles

Yu. F. Ternovoi; A. G. Tsipunov; S. B. Kuratchenko; O. M. Kuimova; K. V. Kondakova

1985-01-01

306

PRODUCTION OF LITHIUM HYDRIDE POWDER  

Microsoft Academic Search

A method for the production of lithium hydride powder is described. ; Lithium carbonate was converted into the chloride. From a saturated solution of ; the chloride lithium amalgam was produced by electrolysis. The lithium amalgam ; was then converted into the hydride by heating the amalgam in a hydrogen ; atmosphere. The apparatus used for the reaction of the

J. Novotny; M. Novotna

1959-01-01

307

Shocks in porous powder media  

NASA Astrophysics Data System (ADS)

Consideration is given to a motion model for a porous powder medium, developed previously to describe the process of combustion-to-detonation transition. The model is applicable up to pressures of 1 kbar. The case of one-dimensional motion is examined, and an effective axial intergranular pressure is introduced whose dependence on porosity during compression is obtained from experimental data.

Vainshtein, P. B.

1988-12-01

308

Metallography of powder metallurgy materials  

Microsoft Academic Search

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

Alan Lawley; Thomas F. Murphy

2003-01-01

309

Experimental Equipment for Powder Processing.  

National Technical Information Service (NTIS)

To increasing the safety factor of the space vehicles, Perspirable Skin, a new designed Thermal Protection System (TPS) was proposed by bio-mimicking the process of human sweating. Powder Metallurgy (P/M) was considered to be the best candidate method to ...

P. Kwon

2009-01-01

310

Forging of Powder Metallurgy Gears.  

National Technical Information Service (NTIS)

The objective of this program was to produce a very near-net shape spur gear by isothermal forging of a powder metallurgy 4600 grade preform. Die fill and densification on test coupons were complete at a forging temperature of 1650F (900C), pressure of 10...

B. L. Ferguson D. T. Ostberg

1980-01-01

311

POWDER COATINGS: A TECHNOLOGY REVIEW  

EPA Science Inventory

In 1995, surface coatings accounted for nearly 2.55 million Mg of volatile organic compound (VOC) emissions nationally, which is more than 12% of VOC emissions from all sources. In recent years, powder coatings have been steadily gaining popularity as an alternative to solvent-bo...

312

Black holes and beyond  

SciTech Connect

The black hole information paradox forces us into a strange situation: we must find a way to break the semiclassical approximation in a domain where no quantum gravity effects would normally be expected. Traditional quantizations of gravity do not exhibit any such breakdown, and this forces us into a difficult corner: either we must give up quantum mechanics or we must accept the existence of troublesome 'remnants'. In string theory, however, the fundamental quanta are extended objects, and it turns out that the bound states of such objects acquire a size that grows with the number of quanta in the bound state. The interior of the black hole gets completely altered to a 'fuzzball' structure, and information is able to escape in radiation from the hole. The semiclassical approximation can break at macroscopic scales due to the large entropy of the hole: the measure in the path integral competes with the classical action, instead of giving a subleading correction. Putting this picture of black hole microstates together with ideas about entangled states leads to a natural set of conjectures on many long-standing questions in gravity: the significance of Rindler and de Sitter entropies, the notion of black hole complementarity, and the fate of an observer falling into a black hole. - Highlights: Black-Right-Pointing-Pointer The information paradox is a serious problem. Black-Right-Pointing-Pointer To solve it we need to find 'hair' on black holes. Black-Right-Pointing-Pointer In string theory we find 'hair' by the fuzzball construction. Black-Right-Pointing-Pointer Fuzzballs help to resolve many other issues in gravity.

Mathur, Samir D., E-mail: mathur.16@osu.edu

2012-11-15

313

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

314

Black Literature vs. Black Studies: Three Lynchings.  

ERIC Educational Resources Information Center

When studying Afro-American literature, even in an English class rather than Black Studies class, both student interest and the topic tend to lead discussion toward sociological, not literary, aspects. However, the teacher should emphasize repeatedly the aesthetic dimensions of an artistic work as well as the various literary forms in which a…

Williams, Melvin G.

315

Black Youth Unemployment and the Black Family.  

ERIC Educational Resources Information Center

This paper analyzes the results of a survey conducted to ascertain the attitudes of 400 employers, youth, and academic/community professionals in Los Angeles, Chicago and Washington, D.C., toward an approach to Black youth unemployment centered on the creation of jobs and training among minority businesses in selected metropolitan areas. Minority…

Hoskins, Linus A.

316

Extreme black hole holography  

NASA Astrophysics Data System (ADS)

The connection between black holes in four dimensions and conformal field theories (CFTs) in two dimensions is explored, focusing on zero temperature (extreme) black holes and their low-temperature cousins. It is shown that extreme black holes in a theory of quantum gravity are holographically dual to field theories living in two dimensions without gravity, and that the field theory reproduces a variety of black hole phenomena in detail. The extreme black hole/CFT correspondence is derived from a symmetry analysis near the horizon of a Kerr black hole with mass M and maximal angular momentum J=M 2. The asymptotic symmetry generators form one copy of the Virasoro algebra with central charge c=12J, which implies that the near-horizon quantum states are identical to those of a two-dimensional CFT. We discuss extensions of this result to near-extreme black holes and cosmological horizons. Astrophysical black holes are never exactly extremal, but the black hole GRS1915+105 observed through X-ray and radio telescopy is likely within 1% of the extremal spin, suggesting that this extraordinary and well studied object is approximately dual to a two-dimensional CFT with c˜1079. As evidence for the correspondence, microstate counting in the CFT is used to derive the Bekenstein-Hawking area law for the Kerr entropy, S=Horizon area/4. Furthermore, the correlators in the dual CFT are shown to reproduce the scattering amplitudes of a charged scalar or spin-½ field by a near-extreme Kerr-Newman black hole, and a neutral spin-1 or spin-2 field by a near-extreme Kerr black hole. Scattering amplitudes probe the vacuum of fields living on the black hole background. For scalars, bound superradiant modes lead to an instability, while for fermions, it is shown that the bound superradiant modes condense and form a Fermi sea which extends well outside the ergosphere. Assuming no further instabilities, the low energy effective theory near the black hole is described by ripples in the Fermi surface. However, in the presence of fermion interactions, the Fermi sea itself can become unstable and condense into a superfluid or superconducting state.

Hartman, Thomas Edward

317

21 CFR 520.445 - Chlortetracycline and sulfamethazine powder.  

Code of Federal Regulations, 2013 CFR

...false Chlortetracycline and sulfamethazine powder. 520.445 Section 520.445 Food...445 Chlortetracycline and sulfamethazine powder. (a) Specifications. Each pound of soluble powder contains chlortetracycline...

2013-04-01

318

Synthesis of La{sup 3+} doped nanocrystalline ceria powder by urea-formaldehyde gel combustion route  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Nano LC synthesized by gel combustion, using urea-formaldehyde fuel for first time. Black-Right-Pointing-Pointer Largely single crystals were produced in average range of 20-30 nm. Black-Right-Pointing-Pointer La{sup 3+} doping increases cell dimension linearly. Black-Right-Pointing-Pointer La{sup 3+} doping introduces ionic point defects but does not change electronic band gap. Black-Right-Pointing-Pointer Presence of Ce{sup 3+} indicates that this synthesis route produces reactive powders. -- Abstract: Nanocrystalline ceria powders doped with various concentrations of lanthanum oxide have been prepared following gel combustion route using for the first time urea-formaldehyde as fuel. The synthesized products were characterized by XRD, FESEM, TEM, PL and UV-vis spectroscopy. Peak positions of XRD were refined and the lattice parameters were obtained by applying Cohen's method. Unit cell parameter increases with concentration of La{sup 3+} ion and the variation is consistently linear. XRD calculations showed the dependence of crystallite size on dopant concentrations at lower level. TEM observation revealed unagglomerated particles to be single crystals in the average range of 20-30 nm. Band gap of the La{sup 3+} doped ceria materials does not change with doping. Spectroscopic experiments proved the existence of Ce{sup 3+} in the formed powder.

Biswas, M. [Central Glass and Ceramic Research Institute, Kolkata 700 032 (India)] [Central Glass and Ceramic Research Institute, Kolkata 700 032 (India); Bandyopadhyay, S., E-mail: sbando@cgcri.res.in [Central Glass and Ceramic Research Institute, Kolkata 700 032 (India)

2012-03-15

319

Application of Powder Technology to Military Hardware.  

National Technical Information Service (NTIS)

A short description of powder metallurgy and its possible application to the manufacture of military hardware is discussed. The first part deals with the experimental aspects of producing compacts from powders. The basic processes of material preparation ...

J. P. Drolet

1972-01-01

320

Titanium Sheet Production from Commercial Powder.  

National Technical Information Service (NTIS)

Powder metallurgy titanium sheet was produced from hydride dehydride (HDH) powder using a diverse industrial supply chain. Three different processing routes were developed and production protocols were established in each route to provide options for manu...

D. Harper T. R. Muth W. Chen W. H. Peter Y. Yamamoto

2013-01-01

321

Process for the Synthesis of Iron Powder.  

National Technical Information Service (NTIS)

A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation fro...

1982-01-01

322

Black College Attendance and Job Success of Black College Graduates.  

ERIC Educational Resources Information Center

Examines the impact of attending a "Black" college on the job success of a sample of Black college graduates employed by a large manufacturing firm. The study finds that graduates of Black colleges start with higher salaries but receive smaller wage increases and fewer promotions than comparable graduates of non-Black colleges. Includes 23…

Solnick, Loren M.

1990-01-01

323

Black hole accretion systems  

NASA Astrophysics Data System (ADS)

Some gamma-ray bursts (GRBs), some X-ray binaries, and all active galactic nuclei (AGN) are likely powered by accretion onto a rotating black hole. I model the global, time-dependent accretion flow around a black hole using the nonradiative viscous hydrodynamic (VHD), Newtonian magnetohydrodynamic (MHD), and general relativistic MHD (GRMHD) equations of motion, which are integrated numerically. I wrote the VHD and nonrelativistic MHD numerical codes, and I coauthored the GRMHD code. I found that GRMHD numerical models of thick disks around a rotating black hole show that an evacuated, nearly force-free magnetosphere develops as predicted by Blandford and Znajek (1977). The BZ solution for the energy extracted is remarkably accurate in this region for a slowly rotating black hole and qualitatively accurate for all rotating black holes. GRMHD numerical models of rapidly rotating black holes show a mildly relativistic, collimated Poynting jet around the polar axis. Currently, no self-consistent MHD model of the accretion flow around a black hole shows a jet with Lorentz factors greater than 3. Additional physics is likely required to obtain Lorentz factors of 100 as some GRB models predict, and to obtain up to Lorentz factors of 10 as observed in some microquasars and AGN.

McKinney, Jonathan C.

324

Point substitutions in Japanese alloalbumins.  

PubMed Central

We have completed the structural study of five rare types of inherited albumin variants (alloalbumins) discovered in the Biochemical Genetics Study of 15,581 unrelated children in Hiroshima and Nagasaki. We have also identified the structural change in five other alloalbumin specimens detected during clinical electrophoresis of sera from Japanese living near Tokyo. Each of the five albumin variants from Nagasaki and Hiroshima has a single amino acid substitution. All of these substitutions differ, and none has been reported in non-Japanese populations. No instances of proalbumin variants or of albumin B (the most frequent alloalbumins in Caucasians) were detected in the children in Hiroshima and Nagasaki. However, one instance of a variant proalbumin and two examples of albumin B occurred in Japanese from the vicinity of Tokyo. In addition a previously unreported point substitution was found in albumin Tochigi, which is present in two unrelated persons from Tochigi prefecture. Four of the point mutations in the Japanese alloalbumins are in close proximity in a short segment of the polypeptide chain (residues 354-382) in which three additional point substitutions have been reported in diverse populations. These results, combined with earlier data, suggest that point substitutions are grouped in certain segments of the albumin molecule. Images

Arai, K; Madison, J; Huss, K; Ishioka, N; Satoh, C; Fujita, M; Neel, J V; Sakurabayashi, I; Putnam, F W

1989-01-01

325

Competitive reactivity of iron towards boron and silicon in surface treatments with powder mixtures  

NASA Astrophysics Data System (ADS)

The processes occurring at the surface of iron in contact with fluoride-activated B4C-base powder mixtures at 850°C were investigated by substituting the diluent SiC with different silicon compounds. The coatings were analyzed by X-ray diffraction, surface Mössbauer spectroscopy and metallographic techniques. The possibility of passing from iron boriding to iron siliciding was shown, and a mechanism proposed for the process.

Carbucicchio, M.; Casagrande, A.; Palombarini, G.

1990-07-01

326

FTIR and XRD evaluation of carbonated hydroxyapatite powders synthesized by wet methods  

Microsoft Academic Search

Carbonated hydroxyapatite powders were obtained by wet method. The CO32? ions were introduced using NH4HCO3 and NaHCO3 in the amount of 0.1 or 0.05M. It was found by FTIR and X-ray studies that fraction of CO32? substitutions in the HAp structure and thermal stability of CHAp depends on the amount and type of carbonate additives. The significant decomposition of carbonated

Anna ?lósarczyk; Zofia Paszkiewicz; Czeslawa Paluszkiewicz

2005-01-01

327

Thermal conductivity of silica aerogel powders at temperatures from 10 to 275 K  

Microsoft Academic Search

Thermal conductivities of physical mixtures of evacuated silica aerogel powders mixed with carbon black were measured as a function of temperature and external load. The measured thermal conductivity results from solid conduction and infrared radiative transport. The latter was quantified with infrared-optical transmission and reflection measurements in the wavelength range 2.3–200 ?m and by solving the radiative heat transfer equation.

Th. Rettelbach; J. Säuberlich; S. Korder; J. Fricke

1995-01-01

328

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

329

Chemical and Physical Properties of Tantalum Powder  

NASA Astrophysics Data System (ADS)

The present work is intended to produce capacitor grade Tantalum powder by sodium reduction of potassium tantalum fluoride prepared from an indigenous ore source. The powder has been characterized for its chemical and physical properties, and compared with the commercially available powders. It is found that indigenous powder has higher impurity levels which could, however, be reduced to acceptance limits. The average particle size is within the prescribed limits.

Purushotham, Y.; Balaji, T.; Kumar, Arbind; Govindaiah, R.; Sharma, M. K.; Sethi, V. C.; Prakash, T. L.

330

Review: aqueous tape casting of ceramic powders  

Microsoft Academic Search

Slurry formulations and processing parameters of the water-based tape casting of ceramic powders are reviewed. Additives include binders, like cellulose ethers, vinyl or acrylic-type polymers; plasticizers, like glycols; and dispersants, like ammonium salts of poly(acrylic acids). Mostly alumina powders have been employed. Hydrophobing of ceramic powders permits the aqueous processing even of water-reactive powders, like aluminium nitride. Non-toxicity and non-inflammability

D. Hotza; P. Greil

1995-01-01

331

METHOD FOR PRODUCTION OF SILVER POWDER  

Microsoft Academic Search

To diversify the range of products JSC Krastsvetmet developed a method for production of electro- lytic silver powders that are widely used in electronic industry for manufacturing contacts. The relevant specification (Silver Powder, TU43-1-702-87) (2) provides for production of two grades of silver powder, PSr1 and PSr2. The grade PSr1 powder shall contain particles with dimensions not larger than 56

E. Pavlov; V. Ilyashevich; S. Zhuravleva

2009-01-01

332

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

333

Black-hole boundaries  

NASA Astrophysics Data System (ADS)

Classical black holes and event horizons are highly nonlocal objects, defined in relation to the causal past of future null infinity. Alternative, quasilocal characterizations of black holes are often used in mathematical, quantum, and numerical relativity. These include apparent, Killing, trapping, isolated, dynamical, and slowly evolving horizons. All of these are closely associated with two-surfaces of zero outward null expansion. This paper reviews the traditional definition of black holes and provides an overview of some of the more recent work on alternative horizons.

Booth, I.

2005-11-01

334

Measuring Black Hole Spin  

NASA Astrophysics Data System (ADS)

WE PROPOSE TO CARRY OUT A SYSTEMATIC STUDY OF EMISSION AND ABSORPTION SPECTRAL FEATURES THAT ARE OFTEN SEEN IN X-RAY SPECTRA OF BLACK HOLE BINARIES. THE EXCELLENT SENSITIVITY AND ENERGY RESOLUTION OF THE ACIS/HETG COMBINATION WILL NOT ONLY HELP RESOLVE AMBIGUITIES IN INTERPRETING THESE FEATURES, BUT MAY ALLOW MODELLING OF THE EMISSION LINE PROFILES IN DETAIL. THE PROFILES MAY CONTAIN INFORMATION ON SUCH FUNDAMENTAL PROPERTIES AS THE SPIN OF BLACK HOLES. THEREFORE, THIS STUDY COULD LEAD TO A MEASUREMENT OF BLACK HOLE SPIN FOR SELECTED SOURCES. THE RESULT CAN THEN BE DIRECTLY COMPARED WITH THOSE FROM PREVIOUS STUDIES BASED ON INDEPENDENT METHODS.

Garmire, Gordon

1999-09-01

335

Effect of Powder Polydispersity on Aerosol Generation  

Microsoft Academic Search

Purpose. We investigated the effect of primary powder polydispersity on the generation of pharmaceutical powder aerosols, using mannitol and bovine serum albu- min (BSA) as the model compounds. Methods. Primary powders with different polydispersity but comparable physical and mass median aerodynamic diameter (MMAD) were obtained from spray drying. The polydispersity, i.e. the width of the particle size distribution, of the

Nora Y. K. Chew; Hak-Kim Chan

336

Reflection of Ultracold Neutrons from Powder Materials.  

National Technical Information Service (NTIS)

Diffusion of ultracold neutrons on powder copper, powder copper oxide and powder graphite has been observed and studied. It was the first experiment to show that it is possible on a level of approx. 10/sup -5/ to determine by measuring the reflection coef...

V. V. Golikov E. N. Kulagin Y. V. Nikitenko

1987-01-01

337

Pourability enhancement of petn explosive powders  

Microsoft Academic Search

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

Marcia Dee Vannet; George L. Ball

1987-01-01

338

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Vanilla powder. 169.179 Section 169.179 Food and Drugs...Dressings and Flavorings § 169.179 Vanilla powder. (a) Vanilla powder is a mixture of ground vanilla beans or...

2013-04-01

339

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Vanilla powder. 169.179 Section 169.179 Food and Drugs...Dressings and Flavorings § 169.179 Vanilla powder. (a) Vanilla powder is a mixture of ground vanilla beans or...

2010-04-01

340

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Vanilla powder. 169.179 Section 169.179 Food and Drugs...Dressings and Flavorings § 169.179 Vanilla powder. (a) Vanilla powder is a mixture of ground vanilla beans or...

2009-04-01

341

21 CFR 73.1645 - Aluminum powder.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum powder. 73.1645 Section 73.1645 Food...CERTIFICATION Drugs § 73.1645 Aluminum powder. (a) Identity. (1) The color additive aluminum powder shall be composed of finely...

2013-04-01

342

21 CFR 73.1647 - Copper powder.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Copper powder. 73.1647 Section 73.1647 Food...CERTIFICATION Drugs § 73.1647 Copper powder. (a) Identity. (1) The color additive copper powder is a very fine free-flowing...

2013-04-01

343

PARTICLE SIZE ANALYSIS OF TUNGSTEN METAL POWDER  

Microsoft Academic Search

A method of particle size analysis for sub-sieve, tungsten metal powder ; has been developed using the Andreasen pipette. Use of 1\\/4 per cent by volume ; of tungsten powder in demineralized water gives minimum agglomeration. The ; method is useful for comparing the distribution of different batches of tungsten ; powder. No correlation between results from this method and

H. J. de Bruin; R. C. Cairns

1957-01-01

344

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

345

Physical Characteristics of Fire-Extinguishing Powders.  

National Technical Information Service (NTIS)

Powders are known to be highly efficient fire-extinguishing agents. There are powders available that, on both weight and volume bases, are more efficient than Halon 1301 as fire-extinguishing agents. A project was undertaken to examine several powders by ...

A. E. Finnerty L. J. VandeKieft A. Drysdale

1997-01-01

346

Effective thermal conductivity of copper powders  

Microsoft Academic Search

Effective thermal conductivity of copper powders of different particle size has been measured experimentally at room temperature and normal pressure using the transient hot strip method. A variation in the values of the effective thermal conductivity of these powders with their porosities is observed. To explain this variation a model for a two-phase system (powders) is developed. Theoretical calculations of

K. Bala; P. R. Pradhan; N. S. Saxena; M. P. Saksena

1989-01-01

347

Prefused Mold Powder and Its Manufacturing Technology,  

National Technical Information Service (NTIS)

The recent need for the continuous casting of steel at higher speed without subsequent surface conditioning urged the development of a new type of mold powder that can replace the conventional blended powders. The prefused powder developed to meet the nee...

T. Kishi T. Nakano T. Maruyamano H. Taniguchi M. Fuji

1987-01-01

348

Theory and Practice of Rolling Metal Powders  

Microsoft Academic Search

The theoretical and technological fundamentals are considered for rolling metal powders. The equipment and production schemes for rolling powders is described as well as unit for feeding powder between rolls for the case of manufacturing two-layer strips. The main technological schemes for production copper rollings are presented.

Gleb A. Vinogradov

2002-01-01

349

High-speed rolling of metal powders  

Microsoft Academic Search

1.A study was made of the rolling of metal powders at velocities of up to 3.2 m\\/sec with forced powder feed into the deformation zone.2.Empirical relationships were obtained enabling the mill output rate and strip thickness and density to be evaluated in terms of roll gap, rolling velocity, and powder head.

A. M. Musikhin; G. A. Vinogradov

1970-01-01

350

A comparison between superfine magnesium hydroxide powders and commercial dry powders on fire suppression effectiveness  

Microsoft Academic Search

The effectiveness of superfine magnesium hydroxide powders and commercial dry powder in fire suppression were compared in a laboratory-scale, immovable fire suppression apparatus. The investigation focused on their suppression effectiveness under various pressures. It likewise studied the relationship between the powders’ surface structures and their effectiveness on fire suppression. The microcosmic structure of the powders was observed by scanning electron

Kaiqian Kuang; Xin Huang; Guangxuan Liao

2008-01-01

351

Thermal Plasma Modification of Titanium Carbide Powder Numerical Analysis of Powder Behavior in Plasmas  

Microsoft Academic Search

Modeling of behavior of TiC powders in an Ar-H2 RF plasma has been performed with the numerical analysis of the plasma fields of velocity, temperature and concentration. The transferred energy to the powders decreases with an increase in the powder feed rate, and with a decrease in the pressure. These parameters have important effects on the powder modification.

T. Watanabe; A. Kanzawa; T. Ishigakiand; Y. Moriyoshi

1995-01-01

352

Black Students and Private Schooling.  

ERIC Educational Resources Information Center

Presents an overview of research on blacks in private schools. Describes which black families send children to private schools, and why; availability of financial assistance; black student achievement in private schools; the quality of education offered to blacks at private schools; and the impact of private schooling on students' racial identity.…

Ascher, Carol

1986-01-01

353

New Directions for Black Women?  

ERIC Educational Resources Information Center

This collection of papers deals with various aspects of the black female experience in America. "The Black Woman in Transition" discusses the effects of sexism and racism on black women with particular reference to employment and education; it is noted that black women, in comparison with other groups in society, suffer a proportionately higher…

McGuigan, Dorothy, Ed.

1978-01-01

354

Influences of powder specifications and powder delivery on laser and powder particle interaction during the LRF process  

NASA Astrophysics Data System (ADS)

With deep studying on the process of laser rapid forming (LRF) the researchers gradually meet the knowledge that it is very important to understand the mechanism of interaction between the laser and the powder particles since it is the key point to realize the effective control of the LRF process. The high-speed photography has been employed to realize in situ observation on the delivery process of powdered materials for the first time. A group of parameters -- delivery parameters of powder is put forward to characterize the delivery process in quantitative by dealing with the digital images obtained. On the basis of quantitative description of the powder delivery, an analytical model is presented to study the attenuation of the laser power caused by the cloud of the power particles. Another analytical model is also presented to study the temperature rise of the particle irradiated by the laser. It can be found that the attenuation ratio is determined together by the powder specifications, the powder feeding parameters and the powder delivery parameters. With the off axial powder nozzle being employed in the paper, the diameter of the powder steam was always bigger than the diameter of laser spot, thus the laser processing parameters have no effect on the laser attenuation. The temperature rise of the particle is determined by the powder specifications and the powder delivery parameters too. Meanwhile the laser processing parameters also affects the temperature rise of the particle. With the decreasing of the particle radius, the irradiation heating effect increases remarkably.

Chen, Jing; Yang, Haiou; Lin, Xin; Huang, Weidong

2005-01-01

355

Magnetic, structural and thermal properties of the Finemet-type powders prepared by mechanical alloying  

NASA Astrophysics Data System (ADS)

The mechanical alloying process has been used to prepare nanocrystalline Fe73.5Si13.5B9Nb3Cu1 powders in a high energy planetary ball-mill Retsch PM400/2. Morphological, microstructural, structural, thermal and magnetic characterizations of the powders milled several times were investigated by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry and hysteresis meter. A mixture of Fe(Si)-type nanograins (14 nm), Fe2B boride phase (˜12 nm), and bcc substitutional Fe(B)-type solid solution is obtained after 150 h of milling. The coercivity and saturation magnetization values are about 62 Oe and 14 emu/g, respectively. Several magnetic transition temperatures are revealed in the DSC scans of the ball-milled powders in the temperature ranges 500-560 °C and 599-606 °C, related to the Fe(B) and Fe(Si)-type phases, respectively.

Alleg, S.; Kartout, S.; Ibrir, M.; Azzaza, S.; Fenineche, N. E.; Suñol, J. J.

2013-04-01

356

Mesoscale Simulations of Powder Compaction  

NASA Astrophysics Data System (ADS)

Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.

Lomov, Ilya.; Fujino, Don; Antoun, Tarabay; Liu, Benjamin

2009-12-01

357

MESOSCALE SIMULATIONS OF POWDER COMPACTION  

SciTech Connect

Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.

Lomov, Ilya; Fujino, Don; Antoun, Tarabay; Liu, Benjamin [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore CA 94551 (United States)

2009-12-28

358

Black Holes in Higher Dimensions  

NASA Astrophysics Data System (ADS)

In four space-time dimensions black holes of Einstein-Maxwell theory satisfy a number of theorems. In more than four space-time dimensions, however, some of the properties of black holes can change. In particular, uniqueness of black holes no longer holds. In five and more dimensions black rings arise. Thus in a certain region of the phase diagram there are three black objects with the same global charges present. Here we discuss properties of higher-dimensional vacuum and charged black holes, which possess a spherical horizon topology, and of vacuum and charged black rings, which have a ringlike horizon topology.

Kunz, Jutta

2014-06-01

359

Characteristics of Gallium-Substituted Hexagonal Mesoporous Silica: Effects of Gallium Content  

Microsoft Academic Search

Gallium-substituted hexagonal mesoporous silicas (Ga-HMS) with various Si\\/Ga ratios in the range of 15 and 200 were prepared at ambient temperature by neutral surfanctant templating pathway. The materials were synthesized by using dodecylamine as a template and tetraethylorthosilicate as a silicon source. They were characterized by energy dispersive X-ray spectroscopy, powder X-ray diffraction (XRD), N2 adsorption-desorption, thermogravimetric analysis, differential scanning

Hsin-Yu Lin; Yu-Lin Pan; Yu-Wen Chen

2005-01-01

360

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

361

Testing bone substitutes in a small animal model of revision arthroplasty  

Microsoft Academic Search

This study evaluated a modification of the rat-pin model to enable testing of bone substitute materials. The model was characterized using the ceramic, ß-tricalcium phosphate (ßTCP) as a filler. A 1 mm wide, 3.6 mm deep defect was created around a stainless steel (SS) implant in the proximal tibia of a rat. This defect was filled with a ceramic powder.

S. A. Clarke; R. A. Brooks; N. Rushton

2002-01-01

362

Substitution reactions of thorium(IV) acetate to synthesize nano-sized carboxylate complexes  

Microsoft Academic Search

Some mixed-ligand thorium(IV) complexes with the general formula [Th(OOCCH3)4?nLn] (L=anions of myristic, palmitic or stearic acid and n=1–4) have been synthesized by the stepwise substitution of acetate ions of thorium(IV) acetate with straight chain carboxylic acids in toluene under reflux. The complexes were characterized by elemental analyses, spectral (electronic, infrared, NMR and powder XRD) studies, electrical conductance and magnetic susceptibility

Balram P. Baranwal; Talat Fatma; Anand Varma; Alok K. Singh

2010-01-01

363

Pixe analysis of powdered milk  

Microsoft Academic Search

An accelerator-based elemental study, using proton-induced x-ray emission (PIXE), was performed on four full-cream and four\\u000a half-cream brands of powdered milk commonly consumed in Jordan. The elements detected in the samples are S, Cl, K, Ca, Fe,\\u000a Cu, Zn, Br, and Rb. The significance of some of these elements is discussed from the viewpoint of nutrition and also their\\u000a effect

A. B. Hallak

1983-01-01

364

Dry PMR-15 Resin Powders  

NASA Technical Reports Server (NTRS)

Shelf lives of PMR-15 polymides lengthened. Procedure involves quenching of monomer reactions by vacuum drying of PRM-15 resin solutions at 70 to 90 degree F immediately after preparation of solutions. Absence of solvent eliminates formation of higher esters and reduces formation of imides to negligible level. Provides fully-formulated dry PMR-15 resin powder readily dissolvable in solvent at room temperature immediately before use. Resins used in variety of aerospace, aeronautical, and commercial applications.

Vannucci, Raymond D.; Roberts, Gary D.

1988-01-01

365

Polycapillary optics for powder diffraction  

Microsoft Academic Search

In this paper, we describe a low power system using Polycapillary collimating and focusing optics that were designed to collect Cu Ka radiation from an Oxford Ultra-Bright micro-focus source for X-ray powder diffraction measurements. The characterizations of the source and polycapillary optics are presented. A collimator with two apertures was used to block high energy X-rays. An optic alignment system

Huapeng Huang; Carolyn A. MacDonald; Walter M. Gibson; John Chik; Adrian Parsegian; Igor Y. Ponomarev

2001-01-01

366

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

367

Introducing the Black Hole  

ERIC Educational Resources Information Center

discusses the cosmology theory of a black hole, a region where an object loses its identity, but mass, charge, and momentum are conserved. Include are three possible formation processes, theorized properties, and three way they might eventually be detected. (DS)

Ruffini, Remo; Wheeler, John A.

1971-01-01

368

BlackWidow  

NSDL National Science Digital Library

BlackWidow (Version 4.1 originally reviewed) is a powerful Website scanning tool and an offline browser. It allows users to download an entire site -- including HTML files, images, cgi files, and more -- with the site structure intact. The intuitive, explorer-style interface makes BlackWidow easy to navigate, and users can specify the depth to download, the file types and sizes, wildcards, etc. Features like displaying the external links in the site (broken links and status of links) will be very useful for Webmasters. Users can simultaneously scan and download multiple sites and also monitor the scanning/downloading process using the Threads window. BlackWidow can scan HTTP, SSL, and FTP sites and can be configured to work with proxies and firewalls. BlackWidow is shareware, and a free trial version is available at the site.

369

Black Hole Explorer Game  

NSDL National Science Digital Library

This board game challenges players (ages 10+) to build a spaceship and fly to a black hole. The game provides opportunities for understanding phenomena based on current black hole research. During the game, players will experience the dangers and excitement of a real space mission, and learn about the nature of black holes by launching scientific probes. The game can be played competitively or as a team (instructions are also provided for playing in large groups. Black Hole Explorer consists of: Game Board, Game Rules, Spacecraft Data sheets, Science Briefing Room document, Event cards (28), Probe result cards (12), Energy tokens (140). Game components are available as PDF downloads; dice and game pieces must be provided by the user. NOTE: tokens and cards need to be cut to size from letter-size cardstock.

370

Imaging Black Holes  

NASA Astrophysics Data System (ADS)

Black holes are simultaneously powerful astrophysical engines and an exotic prediction of general relativity. As a consequence, understanding both the phenomenology of the interactions between astronomical black holes and their environments as well as the peculiar properties of strong gravity and its implications for physics beyond Einstein, is of great interest. Both of these, however, require probing black holes on scales comparable to their event horizon. With the advent of millimeter-wave Very Long Baseline Interferometry, it has now become possible to image a handful of black holes on sub-horizon scales. I will discuss some of the implications that existing observations have already had upon our understanding of accretion, jet formation, and strong field gravity, and how constraints upon these will dramatically improve in the coming years.

Broderick, Avery

2012-03-01

371

21 CFR 520.1628 - Oxfendazole powder and pellets.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Oxfendazole powder and pellets. 520.1628 Section 520...ANIMAL DRUGS § 520.1628 Oxfendazole powder and pellets. (a) Specifications â(1) Powder for suspension. Each gram of powder...

2013-04-01

372

Anti-Corrosive Powder Particles  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) seeks partners for a new approach in protecting embedded steel surfaces from corrosion. Corrosion of reinforced steel in concrete structures is a significant problem for NASA structures at Kennedy Space Center (KSC) because of the close proximity of the structures to salt spray from the nearby Atlantic Ocean. In an effort to minimize the damage to such structures, coatings were developed that could be applied as liquids to the external surfaces of a substrate in which the metal structures were embedded. The Metallic Pigment Powder Particle technology was developed by NASA at KSC. This technology combines the metallic materials into a uniform particle. The resultant powder can be sprayed simultaneously with a liquid binder onto the surface of concrete structures with a uniform distribution of the metallic pigment for optimum cathodic protection of the underlying steel in the concrete. Metallic Pigment Powder Particle technology improves upon the performance of an earlier NASA technology Liquid Galvanic Coating (U.S. Patent No. 6,627,065).

Parker, Donald; MacDowell, Louis, III

2005-01-01

373

Mesoscale simulations of powder compaction  

NASA Astrophysics Data System (ADS)

Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to experimental match compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show evidence of hard-to-explain reshock states above the single-shock Hugoniot line, which have also been observed in the experiments. We found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations, since 2D results tend to underpredict stress levels for high-porosity powders regardless of material properties. We developed a process to extract macroscale information for the simulation which can be directly used in calibration of continuum model for heterogeneous media.

Lomov, Ilya; Antoun, Tarabay; Liu, Benjamin

2009-06-01

374

Black Box Arguments  

Microsoft Academic Search

“Black box argument” is a metaphor for modular components of argumentative discussion that are, within a particular discussion,\\u000a not open to expansion. In public policy debate such as the controversy over abstinence-only sex education, scientific conclusions\\u000a enter the discourse as black boxes consisting of a result returned from an external and largely impenetrable process. In one\\u000a way of looking at

Sally Jackson

2008-01-01

375

Black holes in review  

Microsoft Academic Search

Black holes are the theoretical space-time warps where gravitational forces are so intense that all matter and energy---even light---are effectively trapped and absorbed. So far, there has been no direct evidence, no positive acceptable proof or observation, of black holes, but their incredibly unique properties have been used by modern-day astronomers to provide explanations for many unanswered questions, including those

Peter M. Bell

1982-01-01

376

Black Island telecommunications upgrade  

NSF Publications Database

Title : Black Island telecommunications upgrade Type : Antarctic EAM NSF Org: OD / OPP Date : July 22, 1993 File : opp93107 OFFICE OF POLAR PROGRAMS ENVIRONMENT SECTION 202/357-7766 MEMORANDUM Date: July 22, 1993 From: Acting Environmental Officer Subject: Environmental Action Memorandum (Black Island Telecommunications Facility Upgrade) To: Director, Office of Polar Programs Manager, Polar Operations Section Safety and Health Officer Electronics Engineer Facilities Engineering Projects ...

377

Modified spinning black holes  

NASA Astrophysics Data System (ADS)

In the context of f(R) modified gravity theories we determine that the black holes existence is determined by the sign of a parameter dependent of the mass, the charge, the spin and the scalar curvature. We obtain the different astrophysical objects derived from the presence of different horizons. Thermodynamics for this kind of black holes is studied for negative values of the curvature, revealing that we can distinguish between two kind of BH: fast and slow.

Romero, P. Jimeno; Cembranos, J. A. R.; de la Cruz-Dombriz, A.

2012-07-01

378

Searching for Black Holes  

NASA Technical Reports Server (NTRS)

Our UV/VIS work concentrates on black hole X-ray nova. These objects consist of two stars in close orbit, one of which we believe is a black hole - our goal is to SHOW that one is a black hole. In order to reach this goal we carry out observations in the Optical, UV, IR and X-ray bands, and compare the observations to theoretical models. In the past year, our UV/VIS grant has provided partial support (mainly travel funds and page charges) for work we have done on X-ray nova containing black holes and neutron stars. We have been very successful in obtaining telescope time to support our project - we have completed approximately a dozen separate observing runs averaging 3 days each, using the MMT (5M), Lick 3M, KPNO 2.1M, CTIO 4M, CTIO 1.5M, and the SAO/WO 1.2M telescopes. These observations have allowed the identification of one new black hole (Nova Oph 1977), and allowed the mass of another to be measured (GS2000+25). Perhaps our most exciting new result is the evidence we have gathered for the existence of 'event horizons' in black hole X-ray nova.

Garcia, M.

1998-01-01

379

40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Copper complex of (substituted sulfonaphthyl...Specific Chemical Substances § 721.2577 Copper complex of (substituted sulfonaphthyl...chemical substances identified generically as copper complex of (substituted...

2013-07-01

380

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...  

Code of Federal Regulations, 2010 CFR

...methyl methacrylate, and substituted silane. 721.6920 Section 721.6920 ...methyl methacrylate, and substituted silane. (a) Chemical substance and significant...methyl methacrylate, and substituted silane (PMN P-91-272) is subject to...

2010-07-01

381

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

Code of Federal Regulations, 2012 CFR

...azo substituted sulfocarbopolycle, sodium salt. 721.9545 Section 721.9545 ...azo substituted sulfocarbopolycle, sodium salt. (a) Chemical substance and significant...azo substituted sulfocarbopolycle, sodium salt (PMN P-96-1263) is subject to...

2012-07-01

382

40 CFR 721.1555 - Substituted phenyl azo substituted benzenediazonium salt.  

Code of Federal Regulations, 2010 CFR

...phenyl azo substituted benzenediazonium salt. 721.1555 Section 721.1555 ...phenyl azo substituted benzenediazonium salt. (a) Chemical substance and significant...phenyl azo substituted benzenediazonium salt (PMN P-92-652) is subject to...

2010-07-01

383

FRICTION SOUNDS FOR SENSORY SUBSTITUTION  

Microsoft Academic Search

This paper explores the use of a physics-based sound model of continuous contact for auditory display in interactive set- tings. An audio-visual interactive display is developed in which the sound model is controlled by the user's gestures. The display is used to investigate to what extent audition can substitute for haptic feedback in conveying perception of inertial properties of a

Federico Avanzini; Davide Rocchesso; Stefania Serafin

384

Titanium alloy powder preparation for selective laser sintering  

Microsoft Academic Search

Selective laser sintering (SLS) is a solid freeform fabrication process whereby a part is built layerwise by scanning a powder bed. The processability of metal powder varies depending on the state of the powder prior to SLS. A powder thermal pre-treatment was developed which involved degassing the powder at an elevated temperature in a vacuum. Without powder thermal pre-treatment, the

B. Engel; D. L. Bourell

2000-01-01

385

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.

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

2014-01-01

386

Emerging drugs of abuse: current perspectives on substituted cathinones.  

PubMed

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, Danièle

2014-01-01

387

The relationship between black carbon concentration and black smoke: A more general approach  

NASA Astrophysics Data System (ADS)

The black carbon (BC) component of ambient particulate matter is an important marker for combustion sources and for its impact on human health and radiative forcing. Extensive data archives exist for the black smoke metric, the historic measure of ambient particle darkness. An expression presented in earlier publications (Quincey, 2007; Quincey et al., 2011) for estimating BC concentrations from traditional black smoke measurements is shown to have limitations that can be addressed by using a more systematic approach to the issue of corrections for increasing darkening of the filter. The form of the more general relationship is shown to be an off-axis parabola rather than the on-axis parabola of the earlier work. Existing data from co-located black smoke and aethalometer measurements at 5 UK sites are reanalysed in this context. At very low concentrations of dark particles (British Black Smoke index < ˜10 ?g m-3) a simple linear relationship BC (/?g m-3) ? 0.27·BSIBRITISH will suffice. A parabolic relationship, [BC/?gm]=?{5.2-1.1+1.5×BSI+62-13+19}-7.9-0.9+1.1, quantitatively similar to the previously published relationship will be more reliable for BSIBRITISH values up to 20-25 ?g m-3. The full set of data available was fitted empirically to the off-axis parabola over the range 0-80 ?g m-3 as the quadratic: [BC/?g m-3] = (0.27 ± 0.03) · BSIBRITISH - (4.0 ± 0.2) × 10-4(BSIBRITISH)2, but this curve is highly dependent on the variations between the individual data sets. Adding the extra complexity of the full off-axis parabolic relationship is unlikely to be justified in practical situations. All expressions apply also to the OECD definition of black smoke with the substitution BSIBRITISH = 0.85·BSIOECD. However, in common with the previous approach, they apply only to black smoke values obtained from standard black smoke samplers with 25 mm diameter filters and ˜2 m3 day-1 volumetric flow rate, and presume a value 16.6 m2 g-1 for the specific absorption of BC in ambient particulate matter measured by aethalometry. Fitting uncertainties correspond to imprecision in estimated BC of ±5%, ±12% and ±18% at BSIBRITISH of 5, 20 and 80 ?g m-3, respectively. Spatial and temporal variation in particle ensemble optical properties contributes to uncertainty in BC quantification.

Heal, Mathew R.; Quincey, Paul

2012-07-01

388

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

389

Powder neutron diffraction studies of a carbonate fluorapatite  

SciTech Connect

Atomic positional disorder of a single-phase natural carbonate fluorapatite (francolite) is revealed from analysis of the atomic displacement parameters (ADPs) refined from neutron powder diffraction data as a function of temperature and carbonate content. The ADPs of the francolite show a strong disturbance at the P, O3, and F sites. When it is heat treated to partially or completely remove the carbonate, the ADPs as well as the other structural parameters resemble those of a fluorapatite (Harding pegmatite) that was measured under the same conditions. The various structural changes are consistent with a substitution mechanism whereby the planar carbonate group replaces a phosphate group and lies on the mirror plane of the apatite structure. (c) 2000 Materials Research Society.

Leventouri, Th. [Physics Department, Florida Atlantic University, Boca Raton, Florida 33431 (United States); Chakoumakos, B. C. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393 (United States); Moghaddam, H. Y. [Physics Department, Florida Atlantic University, Boca Raton, Florida 33431 (United States); Perdikatsis, V. [Institute of Geology and Mineral Exploration, Messogion 70, 11527 Athens, (Greece)

2000-02-01

390

Dispersing agents for an aqueous slurry of coal powder  

SciTech Connect

Aqueous dispersions of coal powder having good flowability properties are provided by employing, as the dispersing agent, an anionic surface active agent. The formula of the additives: (R-O-CH2CH2O-MSO3)nm wherein R is an alkyl or alkenyl group having 6 to 22 carbon atoms or an alkyl- or alkenyl-substituted aryl group having 4 to 22 carbon atoms in the substituent thereof, M is an integer from 2 to 50, N is a number of from 1 to 3 and is the same as the valence of the counter ion m, and M is a cation having a valence of from 1 to 3.

Moriyama, N.; Watanabe, S.; Yamamura, M.

1981-11-24

391

Isomorphous substitutions of rare earth elements for calcium in synthetic hydroxyapatites.  

PubMed

Polycrystalline hydroxyapatites Ca(10-x)REE(x)(PO(4))(6)(OH)(2-x)O(x) were synthesized and studied by X-ray powder diffraction, infrared absorption, diffuse-reflectance spectroscopy, and thermogravimetry. The solubility limits x(max) of rare earth elements (REE) in Ca hydroxyapatites decreases with an increasing REE atomic number from x(max) = 2.00 for La, Pr, and Nd to x(max) = 0.20 for Yb at 1100 °C. Refinements of X-ray diffraction patterns by the Rietveld method show that REE atoms substitute for Ca preferentially at the Ca(2) sites of the apatite structure. The substitution decreases the Ca(2)-O(4) atomic distances in the calcium coordination polyhedra and increases the Ca(2)-O(1,2,3) distances. This observation shows that interatomic distances depend not only on radii of the ions involved in the substitution but also on their charges. PMID:20957990

Ardanova, Lyudmyla I; Get'man, Evgeni I; Loboda, Stanislav N; Prisedsky, Vadim V; Tkachenko, Tatiana V; Marchenko, Valeriy I; Antonovich, Valeriy P; Chivireva, Nataliya A; Chebishev, Konstantin A; Lyashenko, Alexandra S

2010-11-15

392

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

393

[Research of genesis of black bands in Burma jadeite].  

PubMed

A kind of jadeite jade with black bands appeared in the mining area of Burma, which presents a gray-black to black appearance. X-ray powder diffraction analysis shows that the components of the sample are mainly jadeite and a small amount of omphacite. A large number of small, dark mineral inclusions were observed by SEM (scanning electron microscopy), distributed in the mineral grain gaps and tensional fractures of jadeite. These inclusions show specific peak at 1582 cm(-1) , and some of them also show a peak at 1346 cm(-1), indicating that these black inclusions are single crystal graphite and amorphous graphite, based on characteristic Raman spectra. These graphite inclusions forming different types of group lead to great light scattering loss in the range of 3000 nm to visible wavelength resulting in large transparency loss and cause the black band in sample. Two series of zircons were found in the sample by microexamination with high crystallinity and inconspicuous metamictization, as testified by Raman spectroscopy. PMID:24369642

Mao, Jian; Chai, Lin-tao; Liu, Xue-liang; Fan, Jian-liang; Xu, Jia-yuan; Jin, Zhi-yuan

2013-09-01

394

Trends in powder processing equipment  

SciTech Connect

Spray drying is the most widely used process for producing particles. It is used in industries other than ceramics including food, chemicals, and pharmaceutical. The process involves the atomization of a liquid feed stock into a spray of droplets and contacting the droplets with hot air in a drying chamber. The sprays are produced by either rotary or nozzle atomizers. Evaporation of moisture from the droplets and formation of dry particles proceed under controlled temperature and airflow conditions. Powder is then discharged continuously from the drying chamber. Spray drying equipment is being improved to handle an ever-increasing number of applications. Several developments in particle-size reduction equipment are also described.

Sheppard, L.M.

1993-05-01

395

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

396

Black diring and infinite nonuniqueness  

SciTech Connect

We show that the S{sup 1}-rotating black rings can be superposed by the solution-generating technique. We analyze the black diring solution for the simplest case of multiple rings. There exists an equilibrium black diring where the conical singularities are cured by the suitable choice of physical parameters. Also there are infinite numbers of black dirings with the same mass and angular momentum. These dirings can have two different continuous limits of single black rings. Therefore, we can transform the fat black ring to the thin ring with the same mass and angular momentum by way of the diring solutions.

Iguchi, Hideo; Mishima, Takashi [Laboratory of Physics, College of Science and Technology, Nihon University, Narashinodai, Funabashi, Chiba 274-8501 (Japan)

2007-03-15

397

A powder particle size effect on ceramic powder based separator for lithium rechargeable battery  

NASA Astrophysics Data System (ADS)

To improve the thermal stability of separators for lithium batteries, we have developed heat-resistant separator films based on ceramic powder. These ceramic powder based separators (CPS) consist of ceramic powder with binder resin. We used two different particle size powders of aluminum oxide (0.01 or 0.3 ?m). By mixing ceramic powder and resin at an appropriate content ratio, both types of CPS films satisfied needs for the heat-resistance. Furthermore, CPS film using 0.01 ?m powder showed excellent charge-discharge cycling properties when applied to lithium rechargeable batteries as a separator.

Takemura, Daigo; Aihara, Shigeru; Hamano, Kouji; Kise, Makiko; Nishimura, Takashi; Urushibata, Hiroaki; Yoshiyasu, Hajimu

398

Preparation of nano-Cr 2? x Al x O 3 ( x = 0–1) solid solution powders by using citrate-dispersant method  

Microsoft Academic Search

A series of nano-Cr2?xAlxO3 (x=0–1) solid solution powders were prepared by sol–gel-chelating processing with citrate-dispersant method. The crystalline structure and size of the Cr2?xAlxO3 powders were determined by X-ray diffraction and transmission electron microscopy. It was demonstrated that the crystalline size of the Cr2?xAlxO3 powders decreases from 33nm to 13nm with an increase in the amount of Al2O3 substitution. The

Jinghong Zhang; Zhonghao Jiang; Dezhen Jin; Xianli Liu

2010-01-01

399

A Crucial Perspective on the Early History of American Black English.  

ERIC Educational Resources Information Center

This study develops specific facts about the nature of the Black English "lingua franca" which formed on the American eastern seaboard in the last half of the eighteenth century. Accepting an assumption that American English of this period was levelling into a "koine," this investigation attempts to characterize the consonant loss and substitution…

Donahue, Thomas S.

400

Foamed lightweight materials made from mixed scrap metal waste powder and sewage sludge ash.  

PubMed

The porous properties and pozzolanic effects of sewage sludge ash (SSA) make it possible to produce lightweight materials. This study explored the effects of different metallic foaming agents, made from waste aluminium products, on the foaming behaviours and engineering characteristics, as well as the microstructure of sewage sludge ash foamed lightweight materials. The results indicated that aluminium powder and mixed scrap metal waste powder possessed similar chemical compositions. After proper pre-treatment, waste aluminium products proved to be ideal substitutes for metallic foaming agents. Increasing the amount of mixed scrap metal waste by 10-15% compared with aluminium powder would produce a similar foaming ratio and compressive strength. The reaction of the metallic foaming agents mainly produced pores larger than 10 microm, different from the hydration reaction of cement that produced pores smaller than 1 microm mostly. To meet the requirements of the lightweight materials characteristics and the compressive strength, the amount of SSA could be up to 60-80% of the total solids. An adequate amount of aluminium powder is 0.5-0.9% of the total solids. Increasing the fineness of the mixed scrap metal waste powder could effectively reduce the amount required and improve the foaming ratio. PMID:15560443

Wang, Kuen-Sheng; Chiou, Ing-Jia

2004-10-01

401

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Benzenesulfonic acid, amino substituted phenylazo-. 721... § 721.1643 Benzenesulfonic acid, amino substituted phenylazo-. ...generically as a benzenesulfonic acid, amino substituted phenylazo-...

2013-07-01

402

Generic substitution of antiepileptic drugs  

PubMed Central

Summary Generic substitution of antiepileptic drugs remains a controversial area without a clear consensus to guide clinicians. The US Food and Drug Administration (FDA) requires rigorous testing of generic products and states that all approved products are interchangeable. FDA studies involve single doses in normal subjects so may not represent the performance of generic products in people with epilepsy. Physician surveys, case reports, and retrospective pharmacy database analyses suggest that antiepileptic drug generic substitution is associated with more health problems and high switchback rates, but these studies have insufficient detail on seizure control and blood levels. Several ongoing prospective randomized trials with rigorous pharmacokinetic methods aim to provide more data for decision-making.

2013-01-01

403

Noncommutative black hole thermodynamics  

SciTech Connect

We give a general derivation, for any static spherically symmetric metric, of the relation T{sub h}=(K/2{pi}) connecting the black hole temperature (T{sub h}) with the surface gravity (K), following the tunneling interpretation of Hawking radiation. This derivation is valid even beyond the semi-classical regime, i.e. when quantum effects are not negligible. The formalism is then applied to a spherically symmetric, stationary noncommutative Schwarzschild space-time. The effects of backreaction are also included. For such a black hole the Hawking temperature is computed in a closed form. A graphical analysis reveals interesting features regarding the variation of the Hawking temperature (including corrections due to noncommutativity and backreaction) with the small radius of the black hole. The entropy and tunneling rate valid for the leading order in the noncommutative parameter are calculated. We also show that the noncommutative Bekenstein-Hawking area law has the same functional form as the usual one.

Banerjee, Rabin; Majhi, Bibhas Ranjan; Samanta, Saurav [S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata-700098 (India)

2008-06-15

404

Understanding Black Hole Mergers  

NASA Astrophysics Data System (ADS)

The field of numerical relativity experienced a phenomenal growth spurt during the past five years. The field transformed from one in which the two-body problem, that is the merger of black-hole binaries, was impossible to solve to one where simulations of merging black-holes are routine. This led to an explosion of exciting new results. Among the most remarkable of them are the discovery that a merging black-hole binary can recoil up to 4000 km/s, the orbital hang-up effect, and the simulation of extreme mass-ratio and extreme spin binaries. The detection gravitational wave signals from these sources will constitute a major breakthrough, opening a new window on the universe. I will cover the latest achievements and highlight the field's next challenges with emphasis on applications to gravitational wave astrophysics, with both current and future generation detectors, and electromagnetic observations.

Campanelli, Manuela

2011-09-01

405

Boosted black string bombs  

NASA Astrophysics Data System (ADS)

We study the formation of superradiant bound states for massive scalar fields in five-dimensional rotating black string geometries with a non-vanishing Kaluza-Klein momentum along the compact direction. Even though all Kaluza-Klein modes may form bound states in this geometry, in realistic extra-dimensional models and astrophysical black holes only the zero-mode is sufficiently light for superradiant instabilities to develop, provided the field has a small but non-vanishing mass, as for example for axion-like particles. We use analytical and numerical methods to show that, although the Kaluza-Klein momentum decreases the upper bound on the field mass for an instability to develop, it may enhance its maximum growth rate by more than 50%, thus boosting the black hole bomb mechanism. We discuss the possible observational consequences of this result and its potential as an astrophysical probe of non-trivial extra-dimensional compactifications.

Rosa, João G.

2013-02-01

406

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

407

On Explicit Substitution with Names  

Microsoft Academic Search

This paper recounts the origins of the ?x family of calculi of explicit substitution with proper variable names, including\\u000a the original result of preservation of strong ?-normalization based on the use of synthetic reductions for garbage collection. We then discuss the properties of a variant\\u000a of the calculus which is also confluent for “open” terms (with meta-variables), and verify that

Kristoffer H. Rose; Roel Bloo; Frédéric Lang

2012-01-01

408

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

409

Slowly balding black holes  

NASA Astrophysics Data System (ADS)

The “no-hair” theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively “frozen in” the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes NB=e??/(?c?), where ???2?2BNSRNS3/(PNSc) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole’s magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

Lyutikov, Maxim; McKinney, Jonathan C.

2011-10-01

410

Cationic substitution in tricalcium aluminate  

SciTech Connect

Cubic and orthorhombic crystals of tricalcium aluminate doped with Na{sub 2}O, Fe{sub 2}O{sub 3} and SiO{sub 2} were prepared and examined using an electron probe microanalyzer. The cationic ratios based on six oxygen atoms were derived from the oxide compositions. These data, together with those in previous studies for clinker aluminates containing Mg{sup 2+} and K{sup +}, provided excellent correlations between Al+Fe and Si (Al+Fe=2.001-1.03Si) and Ca+Mg and Na+K+Si [Ca+Mg=3.006-0.51(Na+K+Si)]. The chemical variation that is constrained by these equations is well accounted for by the general formula (Na,K){sub 2x}(Ca,Mg){sub 3-x-y}[(Al,Fe){sub 1-y}Si{sub y}]{sub 2}O{sub 6}, where x is the amount of Ca substituted by Na and K (0{<=}x<0.158), and y is the amount of Al substituted by Si (0{<=}y<0.136). The crystal system changed from cubic to orthorhombic with increasing x value. The substitution of Si and Fe for Al extended the solid solution range of the orthorhombic phase to lower values of x, while its effect on the solid solution range of the cubic phase was reversed.

Fukuda, Koichiro; Inoue, Shinji; Yoshida, Hideto

2003-11-01

411

Iridium-Catalyzed Allylic Substitution  

NASA Astrophysics Data System (ADS)

Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is generated by a base-induced cyclometalation at the methyl group of this substituent to generate an iridium metalacycle bound by the COD ligand of the [Ir(COD)Cl]2 precursor and one additional labile dative ligand. Such complexes catalyze the reactions of linear allylic esters with alkylamines, arylamines, phenols, alcohols, imides, carbamates, ammonia, enolates and enolate equivalents, as well as typical stabilized carbon nucleophiles generated from malonates and cyanoesters. Iridium catalysts for enantioselective allylic substitution have also been generated from phosphorus ligands with substituents bound by heteroatoms, and an account of the studies of such systems, along with a description of the development of iridium catalysts is included.

Hartwig, John F.; Pouy, Mark J.

412

Resonant photodissociation in substituted benzenes  

NASA Astrophysics Data System (ADS)

Cyclic aromatic molecules are abundant in organic chemistry, with a wide variety of applications, including pharmacology, pollution studies and genetic research. Among the simplest of these molecules is benzene (C6H6), with many relevant molecules being benzene-like with a single atomic substitution. In such a substitution, the substituent determines a characteristic perturbation of the electronic structure of the molecule. We discuss the substitution of halogens into the ring (C6H5X), and its effects on the dynamics of ionization and dissociation of the molecule without the focal volume effect [1]. In particular, using 800-nm, 50-fs laser pulses, we present results in the dissociation of fluorobenzene, chlorobenzene, bromobenzene and iodobenzene into the phenyl ring (C6H5) and the atomic halogen, and the subsequent ionization of these fragments. The impact of the ``heavy atom effect'' on a ^1(?,?*) -> ^3(n,?*) singlet-triplet intersystem crossing will be emphasized. Currently under investigation is whether such a dissociation can be treated as an effective source of the neutral substituent.[4pt] [1] J. Strohaber and C. Uiterwaal, Phys. Rev. Lett. 100 023002 (2008).

Scarborough, Tim; McAcy, Collin; Foote, David; Uiterwaal, Cornelis

2011-06-01

413

Antibacterial characteristics of magnesium oxide powder  

Microsoft Academic Search

The antibacterial activity of magnesium oxide (MgO) was studied. Inhibitory zones appeared around the MgO powder slurry put directly on nutrient agar plates seeded with Escherichia coli or Staphylococcus aureus. However, no zone was observed using a penicillin cup to avoid contact between the bacteria and the MgO powder. Moreover, the supernatant solution of the MgO powder slurry and a

J. Sawai; H. Kojima; H. Igarashi; A. Hashimoto; S. Shoji; T. Sawaki; A. Hakoda; E. Kawada; T. Kokugan; M. Shimizu

2000-01-01

414

Chemical synthesis of magnesium niobate powders  

Microsoft Academic Search

Magnesium niobate (MgNb2O6) powders in orthorhombic form have been successfully prepared via an oxalate synthetic route. Solutions of magnesium chloride hexahydrate and niobium pentachloride were used as the starting materials in the synthesis of MgNb2O6 powders. The formation mechanism of MgNb2O6 was clarified by TG–DTA, FT-IR and X-ray diffraction (XRD). The morphology of the formed powders was examined by scanning

L. Srisombat; Supon Ananta; S. Phanichphant

2004-01-01

415

Process for the synthesis of iron powder  

DOEpatents

A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation from an aqueous mixture of a ferric salt, formic or sulfuric acid, ammonium hydroxide and urea as precipitating agent; and then reducing the dense iron oxide hydroxide by treatment with hydrogen to prepare the iron powder. 2 figs.

Welbon, W.W.

1983-11-08

416

Modeling of laser cladding with powder injection  

Microsoft Academic Search

Laser cladding is one of the material additive manufacturing processes used to produce a metallurgically bonded deposition\\u000a layer. To obtain a high-quality resulting part, a deep understanding of the underlying mechanisms is required. In this article,\\u000a a mathematical model is developed to simulate the coaxial laser-cladding process with powder injection, which includes laser-\\u000a substrate, laser-powder, and powder-substrate interactions. The model

L. Han; K. M. Phatak; F. W. Liou

2004-01-01

417

A method for rubber toughening powder coatings  

Microsoft Academic Search

This paper describes a new method for rubber toughening brittle powder coatings. The design involves the use of toughening agents with specific physical and chemical properties. The modifiers are low-to-medium molecular weight polymers with polymerizable end groups (macromonomers). To achieve the physical properties required for fabrication into fine powders for subsequent deposition using conventional powder coating equipment, semi-crystalline polymers with

J. L. Hedrick; R. D. Allen; A. Diaz; J. G. Hilborn; J. C. Hedrick

1993-01-01

418

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

419

Microbial Quality of Formulated Infant Milk Powders  

Microsoft Academic Search

Study was carried out to examine the microbiological quality of Infant formula milk powder. Total 60 of dried milk powders, 20 each of Group A (1-6), B (7-12) and C (13-18 months). Infant formula milk powders were purchased from Hyderabad, Sindh and evaluated for microbiological examination, like Total Viable Count (TVC), Enterobacteriaceae Count (EbC) and Yeasts and Moulds Count (YMC).

Imran Rashid Rajput; M. Khaskheli; S. Rao; S. A. Fazlani; Q. A. Shah; G. B. Khaskheli

2009-01-01

420

Scattering from black holes  

SciTech Connect

This book provides a comprehensive treatment of the propagation of waves in the presence of black holes. While emphasizing intuitive physical thinking in their treatment of the techniques of analysis of scattering, the authors also include chapters on the rigorous mathematical development of the subject. Introducing the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical (Schwarzschild) black hole, the book then develops the formalism of spin weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic, and gravitational scattering. Details and results of numerical computations are given. The techniques involved have important applications (references are given) in acoustical and radar imaging.

Futterman, J.A.H.; Handler, F.A.; Matzner, R.A.

1987-01-01

421

Loop quantum black hole  

NASA Astrophysics Data System (ADS)

We study the quantum properties of the Kantowski Sachs spacetime, using ideas from loop quantum gravity. This spacetime coincides with the Schwarzschild black hole solution inside the horizon. Recently it was shown that the classical black hole singularity is controlled by the quantum theory, using ADM variables. In this paper we have used Ashtekar-like variables, obtaining information both on quantum effects on the singularity and on the dynamics across the r = 0 singular point. Finally, we have found a regular spacetime inside the horizon and that the dynamics can be extended beyond the classical singularity.

Modesto, Leonardo

2006-09-01

422

Partons and black holes  

SciTech Connect

A light-front renormalization group analysis is applied to study matter which falls into massive black holes, and the related problem of matter with transplankian energies. One finds that the rate of matter spreading over the black hole`s horizon unexpectedly saturates the causality bound. This is related to the transverse growth behavior of transplankian particles as their longitudinal momentum increases. This growth behavior suggests a natural mechanism to implement `t Hooft`s scenario that the universe is an image of data stored on a 2 + 1 dimensional hologram-like projection.

Susskind, L. [Stanford Univ., CA (United States). Physics Dept.; Griffin, P. [Florida Univ., Gainesville, FL (United States). Dept. of Physics

1994-12-31

423

Black Elite: The New Market for Highly Educated Black Americans.  

ERIC Educational Resources Information Center

This examination of the collapse in traditional discriminatory patterns in the market for highly qualified black Americans documents the World War II gain of college trained and related high level black workers, investigates the response of black college students and qualified personnel to the new market setting, and explores the factors that…

Freeman, Richard B.

424

$70 billion in the black: America’s black consumers  

Microsoft Academic Search

$70 Billion in the Black: America's Black Consumers is a marketing analysis of the income and spending habits of black Americans as revealed by census data and studies made by the Bureau of Labor Statistics in the 1970s. This book is a revised and updated edition of D. Parke Gibson's earlier work, The $30 Billion Negro, which was published in

Aurelia Toyer Miller

1979-01-01

425

Dendritic microstructure in argon atomized superalloy powders  

NASA Technical Reports Server (NTRS)

The dendritic microstructure of atomized nickel base superalloy powders (Ni-20 pct Cr, NIMONIC-80A, ASTROALOY, and ZHS6-K) was studied. Prealloyed vacuum induction melted ingots were argon-atomized, the powders were cooled to room temperature, and various powder-size fractions were examined by optical metallography. Linear correlations were obtained for the powder size dependence of the secondary dendrite arm spacing, following the expected d-alpha (R) to the m power dependence on the particle size for all four superalloy compositions. However, the Ni-20 pct Cr alloy, which had much coarser arm spacing as compared to the other three alloys, had a much larger value of m.

Tewari, S. N.; Kumar, Mahundra

1986-01-01

426

Rare earth element exchange through the Bosporus: The Black Sea as a net source of REEs to the Mediterranean Sea  

SciTech Connect

The Bosporus is the only source of seawater to the Black Sea and helps to maintain the basin-wide salinity gradient that caused the Black Sea to become the largest permanently anoxic basin in the world, some 3000 years ago. Concentrations of dissolved rare earth elements (REEs) in each of the three layers of water that make up the Bosporus inflow/outflow system, substituted into a simple hydrographic model that evaluates the entertainment of outflowing Black Sea water in the inflowing Mediterranean Sea water, suggest that the Black Sea acts as a net source of REEs to the Mediterranean Sea. This holds true for Ce, which shows a considerable range of concentrations in the outflowing Black Sea water, even if the lower end of that range is taken to represent the Ce concentration of the Black Sea endmember.

Schijf, J. [Univ. of Utrecht, Amsterdam (Netherlands); De Baar, J.W. [Netherlands Institute for Sea Research, Den Burg (Netherlands)

1995-09-01

427

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

Code of Federal Regulations, 2010 CFR

...dinitrophenyl)azo]diallylamino-4- substituted phenyl] acetamide (generic...dinitrophenyl)azo]diallylamino-4- substituted phenyl] acetamide (generic...dinitrophenyl)azo]diallylamino-4-substituted phenyl]...

2010-07-01

428

"STARS" at Black Island Comms.  

NSF Publications Database

... with Black Island chosen over Arrival Heights, Cape Royds, White Island, Daily Island, Marble Point ... Island. The Black Island site provides an unobstructed horizon of the Pacific Ocean Region (POR ...

429

Health Effects of Black Carbon  

EPA Science Inventory

The purpose of this presentation is to inform the Mid-Atlantic Diesel Collaborative's stakeholders about the health effects of black carbon and convey the relevance of black carbon to their efforts in reducing diesel emissions....

430

Substance Use among Black Adolescents  

MedlinePLUS

... browser. October 4, 2011 Substance Use among Black Adolescents In Brief Compared with the national average for ... 13.5 percent, respectively) Black or African American adolescents have generally been shown to have lower rates ...

431

Towards noncommutative quantum black holes  

SciTech Connect

In this paper we study noncommutative black holes. We use a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate the Hawking's temperature and entropy for the noncommutative Schwarzschild black hole.

Lopez-Dominguez, J. C.; Obregon, O.; Sabido, M.; Ramirez, C. [Instituto de Fisica de la Universidad de Guanajuato, P.O. Box E-143, 37150 Leon Gto. (Mexico); Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Puebla, P.O. Box 1364, 72000 Puebla (Mexico)

2006-10-15

432

Towards noncommutative quantum black holes  

NASA Astrophysics Data System (ADS)

In this paper we study noncommutative black holes. We use a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate the Hawking’s temperature and entropy for the noncommutative Schwarzschild black hole.

López-Domínguez, J. C.; Obregón, O.; Sabido, M.; Ramírez, C.

2006-10-01

433

Superconducting properties of powder-in-tube MgB2 tapes prepared with fine powders  

Microsoft Academic Search

It is necessary to increase the Jc values to develop useful MgB2 tape. We investigated superconducting properties of in situ processed Powder-In-Tube (PIT) MgB2 tapes prepared with fine powders. Fine crystalline Mg powder with the average particle size of about 300 nm was fabricated by applying the thermal plasma method. In addition, 5?15 mol% SiC powder doping was tried to

H. Yamada; M. Hirakawa; H. Kumakura; A. Matsumoto; H. Kitaguchi

2005-01-01

434

Application of powder rheometer to determine powder flow properties and lubrication efficiency of pharmaceutical particulate systems  

Microsoft Academic Search

The objective of this study was to understand the behavior of particulate systems under different conditions of shear dynamics\\u000a before and after granulation and to investigate the efficiency of powder lubrication. Three drug powders, metronidazole, colloidal\\u000a bismuth citrate, and tetracycline hydrochloride, were chosen as model drugs representing noncohesive and cohesive powder systems.\\u000a Each powder was individually granulated with microcrystalline cellulose

Charu V. Navaneethan; Shahrzad Missaghi; Reza Fassihi

2005-01-01

435

Black Progress: Convergence or Cleavage?  

ERIC Educational Resources Information Center

The popular view of a permanent Black underclass falling farther behind an expanding Black middle class is disputed by empirical evidence that the underclass is experiencing upward mobility. The discrepancy stems from social scientists' overreliance on cross-sectional data rather than longitudinal data in analyzing economic change among Blacks

Hill, Robert B.

1982-01-01

436

Blacks, Science, and American Education.  

ERIC Educational Resources Information Center

Blacks are severely underrepresented in the American scientific community; fewer than two percent of all scientists with doctorates in this country are black. Despite civil rights legislation and integration of schools, school systems still fail to encourage black students to consider and prepare for careers in the sciences. In this book, eight…

Pearson, Willie, Jr., Ed.; Bechtel, H. Kenneth, Ed.

437

Health Issues Facing Black Women.  

ERIC Educational Resources Information Center

Black women in the United States experience a high incidence of serious health problems and, as a group, receive insufficient and inadequate medical care. The death rate for black women suffering from breast cancer has increased substantially since 1950. Also of great concern is the high incidence of cervical cancer in low income black women…

Reid, Inez Smith

438

Black hole evaporation: a paradigm  

Microsoft Academic Search

A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: (i) resolution of the Schwarzschild singularity using quantum geometry methods and (ii) time evolution of black holes in the trapping and dynamical horizon frameworks. Quantum geometry effects introduce a major modification in the traditional spacetime diagram of black hole evaporation, providing

Abhay Ashtekar; Martin Bojowald

2005-01-01

439

Energy extraction from higher dimensional black holes and black rings  

SciTech Connect

We analyze the energy extraction by the Penrose process in higher dimensions. Our result shows the efficiency of the process from higher dimensional black holes and black rings can be rather high compared with that in the four-dimensional Kerr black hole. In particular, if one rotation parameter vanishes, the maximum efficiency becomes infinitely large because the angular momentum is not bounded from above. We also apply a catastrophe theory to analyze the stability of black rings. It indicates a branch of black rings with higher rotational energy is unstable, which should be a different type of instability from the Gregory-Laflamme one.

Nozawa, Masato [Department of Physics, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Maeda, Kei-ichi [Department of Physics, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Advanced Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Waseda Institute for Astrophysics, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

2005-04-15

440

Red and Black Game  

NSDL National Science Digital Library

This resource consists of a Java applet and expository text. The applet allows the student to play the game of red and black, by betting on a sequence of Bernoulli trials until either a target is reached or the player is ruined. The target, initial fortune, and trial win probability can be varied.

Siegrist, Kyle

441

Methodology in Black Studies  

ERIC Educational Resources Information Center

The author suggest six methods of approaching Black Studies: (1) study of the contributions of Africans to world culture; (2) study of the influences of African culture on white culture; (3) interdisciplinary study; (4) research designed to test a hypothesis; (5) use of the novel as a teaching tool; and (6) use of historical materials in the…

Bryant, Henry A., Jr.

1975-01-01

442

Normal black kidney  

PubMed Central

A black kidney has 3 major differential diagnoses: hemosiderosis, lipofuscin pigment and melanotic renal cell carcinoma. Excluding lipofuscin, the other 2 are accompanied by an abnormal renal function. We report on a 25-year-old man who intended to donate a kidney to his cousin. On the operating room table when we incised the left flank region and exposed the kidney, we found a firm and black kidney so the operation was cancelled due to potential vascular injuries. Days after the incomplete procedure, we reviewed the donor’s biochemistry and imaging to reassess his renal function, but the results showed quite normal renal function again. The result of Ham test was also negative. Two weeks later, we began the operation, removed the same left kidney and found that it was in the same conditions as it was before. We took the opportunity to send needle biopsies of the kidney for histopathologic analysis. The analysis showed a melanotic kidney without pathological changes in glomeruli and interstitium and vessels. A black kidney may result in hemosiderin, lipofuscin or melanin deposits in the kidney, which can confirm the diagnosis; however, special tests for underlying disease and renal function should be considered. Some causes of black kidney lead to abnormal function, but our patients’s kidney returned to normal.

Yarmohamadi, Aliasghar; Rezayat, Ali Reza Akhavan; Memar, Bahram; Rahimi, Hamid Reza; Cand, PhD

2014-01-01

443

Gasification of black liquor  

DOEpatents

A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

Kohl, Arthur L. (Woodland Hills, CA)

1987-07-28

444

Gasification of black liquor  

DOEpatents

A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediately above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone. 2 figs.

Kohl, A.L.

1987-07-28

445

Black Hole Orbits  

NSDL National Science Digital Library

Students are introduced to the basic properties, behavior and detection of black holes through a brief discussion of common conceptions and misconceptions of these exciting objects. They "act out" a way black holes might be detected through their interaction with other objects. In this activity, girls represent binary star systems in pairs, walking slowly around one another in a darkened room with each pair holding loops of wire to simulate the gravitational interaction. Most of the students are wearing glow-in-the-dark headbands to simulate stars, some are without headbands to represent black holes, and a small set of the black holes have flashlights to simulate X-ray emission. This activity is part of a series that has been designed specifically for use with Girl Scouts, but the activities can be used in other settings. Most of the materials are inexpensive or easily found. It is recommended that a leader with astronomy knowledge lead the activities, or at least be available to answer questions, whenever possible.

446

Empowering Young Black Males  

ERIC Educational Resources Information Center

Of all the challenges we face in education today, the author can think of none greater than the challenge of motivating, educating, and empowering black male learners. The fact that this group of students is in crisis is evident on multiple levels, starting with graduation rates. According to the Schott Foundation (2008), the U.S. high school…

Kafele, Baruti K.

2012-01-01

447

Black Field of Dreams.  

ERIC Educational Resources Information Center

Proposes a model for improving the structure of enculturation such that young (and older) African Americans can experience broader access to routes of black social and economic mobility. The model is based on observation of enculturation in and around community-based sports clubs in New Zealand. Suggests that components of the club structure would…

Andrews, Vernon L.

2000-01-01

448

Black Sea Battle  

NSDL National Science Digital Library

Story of the invasion of jellyfish into the Black Sea and the resulting affects on the native fish population. An excellent introduction into introduced species and their effects on an ecosystem. Site features an abundance of information on alien species and the delicacy that goes into eradicating them. Also links to additional non-traditional science-related news events.

449

Black Canyon Outreach Education  

NSDL National Science Digital Library

This portal features links to K-12 outreach education units on the Black Canyon of the Gunnison National Park and Curecanti National Recreation Area. They focus on topics such as trees, habitats, fossils, animal adaptations, seasons, weather, the water cycle, mapping and geology. There are also downloadable activities for sutdents to perform either before or after their visits to the area.

450

Rotating black hole hair  

NASA Astrophysics Data System (ADS)

A Kerr black hole sporting cosmic string hair is studied in the context of the abelian Higgs model vortex. It is shown that such a system displays much richer phenomenology than its static Schwarzschild or Reissner-Nordstrom cousins, for example, the rotation generates a near horizon `electric' field. In the case of an extremal rotating black hole, two phases of the Higgs hair are possible: large black holes exhibit standard hair, with the vortex piercing the event horizon. Small black holes on the other hand, exhibit a flux-expelled solution, with the gauge and scalar field remaining identically in their false vacuum state on the event horizon. This solution however is extremely sensitive to confirm numerically, and we conjecture that it is unstable due to a supperradiant mechanism similar to the Kerr-adS instability. Finally, we compute the gravitational back reaction of the vortex, which turns out to be far more nuanced than a simple conical deficit. While the string produces a conical effect, it is conical with respect to a local co-rotating frame, not with respect to the static frame at infinity.

Gregory, Ruth; Kubiz?ák, David; Wills, Danielle

2013-06-01

451

Teaching the Black Experience.  

ERIC Educational Resources Information Center

Instructional materials and teaching approaches can be used to get students to seriously and constructively confront problems in race relations which they will eventually have to solve. For example, Richard Wright's "Black Boy," an anthology of Negro poetry or a collection of poems on race relations, and such films as "Where is Prejudice?" can…

Kirschenbaum, Howard

1968-01-01

452

Black Hole Magnetospheres  

NASA Astrophysics Data System (ADS)

We investigate the structure of the steady-state force-free magnetosphere around a Kerr black hole in various astrophysical settings. The solution ?(r, ?) depends on the distributions of the magnetic field line angular velocity ?(?) and the poloidal electric current I(?). These are obtained self-consistently as eigenfunctions that allow the solution to smoothly cross the two singular surfaces of the problem, the inner light surface inside the ergosphere, and the outer light surface, which is the generalization of the pulsar light cylinder. Magnetic field configurations that cross both singular surfaces (e.g., monopole, paraboloidal) are uniquely determined. Configurations that cross only one light surface (e.g., the artificial case of a rotating black hole embedded in a vertical magnetic field) are degenerate. We show that, similar to pulsars, black hole magnetospheres naturally develop an electric current sheet that potentially plays a very important role in the dissipation of black hole rotational energy and in the emission of high-energy radiation.

Nathanail, Antonios; Contopoulos, Ioannis

2014-06-01

453

Gasification of black liquor  

Microsoft Academic Search

A process is described for treating a concentrated aqueous black liquor carbonaceous material and alkali metal sulfur compounds to form a combustible gas and a sulfide-rich melt comprising: (a) providing a gasifier vessel maintained at a pressure of from about 1 to 50 atmospheres and containing a relatively shallow molten salt pool at its bottom within a sump equipped with

Kohl

1987-01-01

454

Dictionary of Black Culture.  

ERIC Educational Resources Information Center

This dictionary is an encyclopedic survey of the cultural background and development of the black American, covering the basic issues, events, contributions and biographies germane to the subject. The author-compiler is Chairman of Classical Languages Department at Southeastern State College, Durant, Oklahoma. Richard Runes is practicing law as a…

Baskin, Wade; Runes, Richard N.

455

Twistors and black holes  

Microsoft Academic Search

Motivated by black hole physics in Script N = 2, D = 4 supergravity, we study the geometry of quaternionic-Kähler manifolds Script M obtained by the c-map construction from projective special Kähler manifolds Script Ms. Improving on earlier treatments, we compute the Kähler potentials on the twistor space Script Z and Swann space Script S in the complex coordinates adapted

Andrew Neitzke; Boris Pioline; Stefan Vandoren

2007-01-01

456

Black History Month.  

ERIC Educational Resources Information Center

This annotated subject guide to Web sites and additional resources focuses on Black History month. Specifies age levels for resources that include Web sites, CD-ROMs and software, videos, books, audios, magazines; includes professional resources; and presents a relevant class activity. (LRW)

Web Feet K-8, 2000

2000-01-01

457

African Psychology and Black Personality Testing.  

ERIC Educational Resources Information Center

The following instruments for measuring Black personality use the world view and cultural orientations of Africa have been developed and are described: (1) the Black Personality Questionnaire; (2) the Black Preference Inventory; (3) the Black Opinion Scale; (4) the Themes of Black Awareness Test; (5) the Themes Concerning Blacks Test; and (6) the…

Baldwin, Joseph A.

1987-01-01

458

The Role of Powder Particle Size Distribution in the Processability of Powder Injection Molding Compounds  

Microsoft Academic Search

The role of particle size distribution of hard-metal carbide powder compounds in structural changes caused by shear deformation is investigated via their response to dynamic viscoelastic strain. Materials employed in the study are intended for the production of sintered carbide components via powder injection molding. Four grades of hard-metal carbide powders differing in their particle size distribution were mixed thoroughly

B. Hausnerova; T. Kitano; I. Kuritka; J. Prindis; L. Marcanikova

2011-01-01

459

Thermal conductivity of metal powder-polymer feedstock for powder injection moulding  

Microsoft Academic Search

Thermal conductivity of a powder injection moulding feedstock (mixture of metal powders and polymers) in solid and molten states has been measured by using the laser flash method. The filler material was 316L stainless steel powder and its content in the mixture amounted 60% by volume. An attempt has been made to employ two most promising existing mathematical models (theoretical

L. Kowalski; J. Duszczyk; L. Katgerman

1999-01-01

460

PowderSolve – a complete package for crystal structure solution from powder diffraction patterns  

Microsoft Academic Search

Powder diffraction techniques are becoming increasingly popular as tools for the determination of crystal structures. The authors of this paper have developed a software package, named PowderSolve, to solve crystal structures from experi- mental powder diffraction patterns and have applied this package to solve the crystal structures of organic compounds with up to 18 variable degrees of freedom (defined in

G. E. Engel; S. Wilke; O. König; K. D. M. Harris; F. J. J. Leusen

1999-01-01

461

Study of a tissue equivalent gelatine based tissue substitute.  

National Technical Information Service (NTIS)

A study of several tissue substitutes for use as volumetric dosimeters was performed. The tissue substitutes studied included tissue substitutes from previous studies and from ICRU 44. The substitutes were evaluated for an overall match to Reference Man w...

J. L. Spence

1992-01-01

462

Method for producing coral powder  

US Patent & Trademark Office Database

A coral is washed with purified water or tap water, and a crushed coral is heat-treated. Proteins and other organic matter are incorporated between calcium molecules in the coral skeleton, and the organic matter is decomposed and released as volatile components. In the skeleton from which organic matter is released, a calcium skeleton having a porous structure is formed, and the surface area of pores is increased. A hydrogen gas can be retained in the structure by adsorbing a hydrogen gas to the pores in such a calcium skeleton a porous structure (micropores). The resulting coral powder, with which ions dissolved in water are easily extracted, shows a low oxidation reduction potential when dissolved in water.

2012-05-01

463

Pulsed laser deposition of strontium-substituted hydroxyapatite coatings  

NASA Astrophysics Data System (ADS)

The growing evidence of the beneficial role of strontium in bone has increased the interest of developing strontium-containing biomaterials for medical applications, and specifically biocompatible coatings that can be deposited on metallic implants to benefit from their load-bearing capabilities. In this work, strontium-substituted hydroxyapatite (Sr-HA) coatings have been fabricated by pulsed laser deposition (PLD) from initial targets obtained after mixing and compacting commercial HA and SrCO3 powders in different proportions. The films thus fabricated were then structurally, morphologically and chemically characterized using scanning electron microscopy, optical profilometry, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The macroscopic morphology of the films presented in all cases equivalent spherical shaped aggregates of typical calcium phosphate coatings. The results reveal, however, the incorporation of Sr2+ and carbonate groups in the coatings as a function of the SrCO3 content in the ablation target, being the incorporation of Sr2+ a linear phenomenon that is accompanied by a similarly linear withdrawal of Ca2+. The role of Sr2+ in the modification of the HA structure and a possible mechanism of substitution of Sr2+ atoms in place of Ca2+ atoms are discussed.

Pereiro, I.; Rodríguez-Valencia, C.; Serra, C.; Solla, E. L.; Serra, J.; González, P.

2012-09-01

464

Oxidation sizing of iron and iron-neodymium-boron powders  

Microsoft Academic Search

A powder sizing test developed for use on WC powders has been extended for use on iron and iron-neodymium-boron powders. In this test the particle size is derived from the rate of oxidation, because finer powders oxidize quicker. The rate of oxidation is monitored in a thermogravimetric analyser, where the powders are subjected to a controlled heating rate from room

M. Stewart; B. Roebuck; M. G. Gee

1991-01-01

465

Ignition of Titanium Powder Layers by Electrostatic Discharge  

Microsoft Academic Search

Titanium powder heating and ignition by an electrostatic discharge (ESD) or spark was investigated. The effect of powder layer thickness and morphology was determined. Ti powder was chosen for these experiments because it is commonly found in energetic formulations, used for materials preparation by self-propagating high-temperature synthesis, and is extensively used in powder metallurgy. Two Ti powders were used: spherical

Ervin Beloni; Edward L. Dreizin

2011-01-01

466

Electrical Resistivity of Metal Powder Aggregates  

Microsoft Academic Search

An equation for calculating the electrical resistivity of a compressed powder mass, consisting of oxide-coated metal particles, has been derived. In addition to the intrinsic interest of the problem, the proposed equation is useful for describing the very early stages of electrical sintering processes. The problem is approached in a new way, relating the actual powder system to an equivalent

J. M. Montes; F. G. Cuevas; J. Cintas

2007-01-01

467

Dynamic Powder Feeding System for Laser Cladding.  

National Technical Information Service (NTIS)

A powder feeding equipment has been designed for laser cladding. Tests have showed that the powder feeder is able to deliver a flow rate from 1.5 - 40 g/min, with a tolerance better than + or - 2% measured over a period of 30 seconds. This makes the feede...

T. A. Jensen

1990-01-01

468

Process for Thickening and Sintering Powders.  

National Technical Information Service (NTIS)

A process is described for thickening and sintering powders of metals, metal carbides, or ceramic or similar materials, in which the powder is stirred into a metal container and heated to a high temperature within this form. At the same time the air is ev...

P. Riegelmayer

1969-01-01

469

Grinding and Characterization of Scrap Rubbers Powders  

Microsoft Academic Search

SBR and EPDM extruded profile scraps are ground under ambient conditions for further utilization in recycling and reclaiming processes. The obtained powders (SBR-r and EPDM-r, respectively) are physically, thermally, and chemically characterized and the results are analyzed as for its suitability for reuse methods. It is possible to obtain powdered SBR and EPDM rubber with irregular shape and high surface

Tatiana Weber; Aline Zanchet; Rosmary N. Brandalise; Janaina S. Crespo; Regina C. R. Nunes

2008-01-01

470

Large Bore Powder Gun Qualification (U)  

Microsoft Academic Search

A Large Bore Powder Gun (LBPG) is being designed to enable experimentalists to characterize material behavior outside the capabilities of the NNSS JASPER and LANL TA-55 PF-4 guns. The combination of these three guns will create a capability to conduct impact experiments over a wide range of pressures and shock profiles. The Large Bore Powder Gun will be fielded at

Donald A. Rabern; Robert Valdiviez

2012-01-01

471

Caking phenomena in amorphous food powders  

Microsoft Academic Search

Caking of free-flowing powders during storage is a deleterious phenomenon that is ubiquitous in the feed, fertilizer and pharmaceutical industries, and of economical importance for low-moisture foods. Among other subjects related to caking of amorphous powders, the following aspects are reviewed in this article: (1) physical and morphological changes, and quantitative procedures to assess caking; (2) proposed mechanisms of caking

José M. Aguilera; José M. del Valle; Marcus Karel

1995-01-01

472

Constitutive mechanical modeling of BSCCO powders  

Microsoft Academic Search

In order to feed a new mechanical model of the Powder In Tube (PIT) processing BSCCO\\/Ag conductors, a plastically compressible constitutive model of the powder is proposed and its parameters measured. We use a simple compressible model of the CAM-CLAY type with work hardening and softening depending on density variation. The unknown parameters of the model, the plastic properties of

A. Allais; C. E. Bruzek; N. Lallouet; P. Montmitonnet; P. Herrmann; D. Pelissier; F. Toussaint

2003-01-01

473

Simulation and modeling of cohesive powder flow  

Microsoft Academic Search

Simulation and modeling of the flow behavior of cohesive powders are carried out through discrete element simulation (DES) and the kinetic theory of gas-based continuum model to gain a fundamental understanding of the cohesive powder flows. The cohesive forces between particles, such as van der Waal's forces, are accounted for by particle surface energy through a microscopic contact force model.

Hong Shang

1998-01-01

474

Adsorption of arsenate on untreated dolomite powder  

Microsoft Academic Search

Raw dolomite powder was evaluated for its efficiency in adsorbing As(V) from water. An experimental setup comprised of a fluidized dolomite powder bed was used to assess the impact of various test variables on the efficiency of removal of As(V). Test influents including distilled water (DW), synthetic groundwater (SGW) and filtered sewage effluent (FSE) were employed to assess the effect

G. M. Ayoub; M. Mehawej

2007-01-01

475

FBE powder and coating tests evaluated  

Microsoft Academic Search

Properties of a fusion-bonded epoxy (FBE) external pipeline coating can be significantly affected by the conditions under which the FBE powder has been stored. Nova, An Alberta Corporation, and 3M Co. undertook a program of evaluating easily run tests to determine the suitability of FBE powder. These tests are less time consuming than the most commonly used series of tests

K. E. W. Coulson; D. G. Temple; J. A. Kehr

1987-01-01

476

21 CFR 529.2464 - Ticarcillin powder.  

Code of Federal Regulations, 2013 CFR

... 6 2013-04-01 2013-04-01 false Ticarcillin powder. 529.2464 Section 529.2464 Food and Drugs FOOD...OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.2464 Ticarcillin powder. (a) Specifications. Each vial contains...

2013-04-01

477

Compatibility of header materials with pyrotechnic powder  

Microsoft Academic Search

The intent of this research program is to qualify several stainless steels, nickel-base alloys and a titanium alloy as candidates for explosive component applications. This report focuses on the compatibility of these materials with pyrotechnic powder. The powder is a combined titanium subhydride-potassium perchlorate mixture, used both wet and dry. Hollow tensile bars were utilized to discern interactions between the

Weirick

1982-01-01

478

Subharmonic Square Waves for a Vibrated Powder  

Microsoft Academic Search

We describe experiments on vibrated powders in a gas environment. Because the powders are fine, typically about 60 mum in diameter, the system is inherently two-phase in nature. In the experiments, we control the amplitude and frequency of shaking and the ambient pressure, P. At high enough accelerations, subharmonic waves appear. We focus on a novel wave form that consists

Jean-Philippe Matas; Jun Uehara; Bob Behringer

2006-01-01

479

Preparation of Silver Powder for Conductive Paste.  

National Technical Information Service (NTIS)

A novel technology for preparing silver flake powder has been studied. The solution containing KAg(CN)2 was reduced by suspension mixture of formaldehyde and benzaldehyde with surfactant TN, and luminous silver flake powder with an average particle size o...

L. Y. Chai, H. Zhong, H. Wu

1994-01-01

480

Predicting the conductivity of biporous powder materials  

Microsoft Academic Search

The electrical conductivity of biporous permeable powdered materials is calculated on the basis of percolation theory. These\\u000a materials are made with a pore-forming additive having a different ratio of particle size than does the metal phase. Calculations\\u000a for nickel powder specimens as an example are in satisfactory agreement with the experimental data.

Y. N. Kruchkov; L. I. Chernyshev; L. E. Lunin

2000-01-01

481

Slip casting and nitridation of silicon powder  

NASA Astrophysics Data System (ADS)

Powdered Silicon was slip-cast with a CaSO4 x 0.5H2O mold and nitrided in a N atm. containing 0 or 5 vol. % H at 1000 to 1420 deg. To remove the castings, the modeling faces were coated successively with an aq. salt soap and powdered cellulose containing Na alginate, and thus prevented the sticking problem.

Seiko, Y.

1985-03-01

482

Physical and dielectric properties of pharmaceutical powders  

Microsoft Academic Search

The limited availability of published physical and dielectric property data for pharmaceutical powders hinders the design of processing systems, particularly dryers. In this study, the physical properties (solubility and boiling point) and dielectric properties, in terms of temperature rise, dielectric constant, and dielectric loss factor, of selected pharmaceutical powders were measured. The pharmaceutical actives, paracetamol and aspirin, and selected common

C. M McLoughlin; W. A. M McMinn; T. R. A Magee

2003-01-01

483

Soluble dietary fibres in Jerusalem artichoke powders: composition and application in bread.  

PubMed

Powders of tubers from Jerusalem artichoke (Helianthus tuberosus, L.), cultivar Gigant, of different harvesting times (autumn and spring) were applied in bakery products, particularly in wheat/rye bread. The quality of this bread was compared to bread with cereal flours substituted with commercial products as Raftilin ST and Raftilose P95. Compared to standard and substituted bread, Jerusalem artichoke bread shows a high quality in organoleptic evaluation (grade I with 36.5 and 37.5 scores). In utilised Jerusalem artichoke powders (JAPs) the amount of fructan (inulin) hydrolysis to fructose during the baking process depends on its initial degree of polymerisation (dp). With JAP of autumn harvest (fructan: dpn = 9.9, dpw = 21.8) less fructose (24.6%) is formed than with those of spring harvest (fructan: dpn = 4.9, dpw = 7.1) (40.7%). Compared to this bread, substitution with commercial products Raftilin ST (inulin: dpn = 8.4, dpw = 17.4) and Raftilose P95 (fructo-oligosaccharides: dpn = 2.7, dpw = 3.0) yields 11.9% and 45.8% of fructose upon total hydrolysis, respectively. The loss of fructan content by the bakery process is 38% in bread with JAP of autumn and 43% in bread with JAP of spring harvest; Raftilin ST- and Raftilose P95-bread come up with loss of fructan content of 35% and 47%, respectively. PMID:12108213

Praznik, W; Cie?lik, E; Filipiak-Florkiewicz, A

2002-06-01

484

Thoria powder process development (LWBR Development Program)  

SciTech Connect

The development program to identify the critical parameters for the process of converting thorium nitrate solution into thoria powder is described. Thorium oxalate hexahydrate is precipitated from the reaction of thorium nitrate solution with oxalic acid. The resulting thorium oxalate hexahydrate slurry is filter pressed into a cake which is air calcined to form thoria powder. Changes in the critical processing parameters such as free nitric acid content of the thorium nitrate solution, precipitation temperature, and calcining temperature altered the thoria powder characteristics, and thus its capability for being fabricated into fuel pellets. The objective of the powder preparation effort was to obtain thoria powders which could be formed by conventional ceramic fabrication techniques into thoria and thoria-urania pellets of high density and high integrity having a nearly uniform large grain structure.

Hutchison, C.R.; Lloyd, R.

1979-10-01

485

Wet powder seal for gas containment  

DOEpatents

A gas seal is formed by a compact layer of an insoluble powder and liquid filling the fine interstices of that layer. The smaller the particle size of the selected powder, such as sand or talc, the finer will be the interstices or capillary spaces in the layer and the greater will be the resulting sealing capacity, i.e., the gas pressure differential which the wet powder layer can withstand. Such wet powder seal is useful in constructing underground gas reservoirs or storage cavities for nuclear wastes as well as stopping leaks in gas mains buried under ground or situated under water. The sealing capacity of the wet powder seal can be augmented by the hydrostatic head of a liquid body established over the seal.

Stang, Louis G. (Sayville, NY) [Sayville, NY

1982-01-01

486

Effect of detergent on powder triboelectrification.  

PubMed

Triboelectrification of pharmaceutical powders during processing and manufacture may cause adhesion/cohesion effects, reduce fill and dose uniformity, affect powder flow and packing behaviour and even obstruct the manufacturing of the product. This paper presents the results of an experimental study on the triboelectrification of microcrystalline cellulose in contact with stainles