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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

Analysis of ascorbic acid based black powder substitutes by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry.  

PubMed

Black powder substitutes are an important sub-group of explosive propellants in the United States because they are readily accessible, and can be used as fillers for improvised explosive devices. Many brands of black powder substitutes incorporate an ascorbic acid fuel source with potassium nitrate (KNO(3)) and/or potassium perchlorate (KClO(4)) oxidizer(s). A gradient high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC/ESI-QToFMS) method has been developed for the analysis of both the organic and the inorganic constituents. The HPLC/ESI-QToFMS method was utilized to examine aqueous extracts of intact samples and post-burn residues from six different brands of ascorbic acid based powders. Aqueous extracts of the post-blast residues from two brands of ascorbic acid based propellant were also analyzed. The results showed that both the ascorbic acid fuel and the inorganic oxidizer(s) KClO(4) and/or KNO(3) were successfully detected via the [M-H](-) ion of ascorbic acid and the anions (ClO(4) (-) and NO(3) (-)) of the oxidizers. This method was proven to be a rapid and efficient procedure for the analysis of this class of explosives. The high mass resolution provided by the QToFMS instrument fulfills the degree of certainty required in a court of law. PMID:20391612

Bottegal, Megan; Lang, Lisa; Miller, Mark; McCord, Bruce

2010-05-15

3

Comprehensive Review of Black Powder.  

National Technical Information Service (NTIS)

A diligent attempt has been made to scrutinize black powder and the charcoal it contains as fully as possible, utilizing modern testing techniques and various analytical chemical procedures. Although the tests performed are well established, their applica...

R. A. Sasse

1985-01-01

4

30 CFR 56.6901 - Black powder.  

Code of Federal Regulations, 2013 CFR

...6901 Black powder. (a) Black powder shall be used for...stone. (b) Containers of black powder shall beâ (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2013-07-01

5

30 CFR 57.6901 - Black powder.  

Code of Federal Regulations, 2010 CFR

...6901 Black powder. (a) Black powder shall be used for...stone. (b) Containers of black powder shall beâ (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2009-07-01

6

30 CFR 56.6901 - Black powder.  

Code of Federal Regulations, 2010 CFR

...6901 Black powder. (a) Black powder shall be used for...stone. (b) Containers of black powder shall beâ (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2010-07-01

7

30 CFR 56.6901 - Black powder.  

Code of Federal Regulations, 2010 CFR

...6901 Black powder. (a) Black powder shall be used for...stone. (b) Containers of black powder shall beâ (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2009-07-01

8

30 CFR 57.6901 - Black powder.  

Code of Federal Regulations, 2010 CFR

...6901 Black powder. (a) Black powder shall be used for...stone. (b) Containers of black powder shall beâ (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2010-07-01

9

Thermal analysis of black powder  

Microsoft Academic Search

While there is abundant literature describing the factors affecting the performance and the mechanical sensitivity of black\\u000a powder, only a few papers are devoted to its thermal properties. Previous work indicated that no exothermic reactions were\\u000a observed below 300C in an inert gas environment. In the present work a variety of thermal techniques (DSC, TG, simultaneous\\u000a TG-DTA-FTIR-MS, ARC, HFC) has

R. Turcotte; R. C. Fouchard; A.-M. Turcotte; D. E. G. Jones

2003-01-01

10

30 CFR 57.6901 - Black powder.  

Code of Federal Regulations, 2013 CFR

... SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives...General Requirements-Surface and Underground § 57.6901 Black powder...open flame; (ii) Within any building in which a fuel-fired or...

2013-07-01

11

Carbon Black Filled Powdered Natural Rubber  

Microsoft Academic Search

Carbon black filled powdered natural rubber (P(NR\\/N234)) was prepared using a patented method of latex\\/carbon black coagulation technology. The influence of curing recipes and carbon black contents on the curing properties, mechanical properties, and dynamic properties were studied in depth, and the results were compared with that of NR\\/N234 compounds based on traditional dry mixing of bale natural rubber and

YANFEN LIN; ANQIANG ZHANG; LIANSHI WANG; CHENGYU PEI; QIN GU

2011-01-01

12

The Chemical and Ballistic Properties of Black Powder.  

National Technical Information Service (NTIS)

The chemical and ballistic properties of black powder are described in terms of storage stability, hygroscopicity, ignition sensitivity, compatibility with other materials, and burning rate. Information is included on uses and users of black powder and so...

R. A. Whiting

1970-01-01

13

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

14

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 2009-10-01 false Black powder for small arms. 173.170 Section 173...Other Than Class 1 and Class 7 § 173.170 Black powder for small arms. Black powder for small arms that has been classed...

2009-10-01

15

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Black powder for small arms. 173.170 Section 173...Other Than Class 1 and Class 7 § 173.170 Black powder for small arms. Black powder for small arms that has been classed...

2010-10-01

16

Carbon Black Filled Powdered Natural Rubber  

Microsoft Academic Search

Carbon black (CB) filled powdered natural rubber [P(NR\\/N234)] was prepared using a patented method of latex\\/CB coagulation technology. The influence of curing recipes and CB contents on the curing, mechanical, and dynamic properties were studied in depth, and the results were compared with that of NR\\/N234 compounds based on traditional dry mixing of bale NR and CB. The results showed

Yanfen Lin; Anqiang Zhang; Lianshi Wang; Chengyu Pei; Qin Gu

2012-01-01

17

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

18

Death by black powder revolver: a case report  

Microsoft Academic Search

Deaths resulting from the use of black powder handguns are relatively uncommon compared to other firearms. We report the case\\u000a of a 48 year-old woman who sustained a lethal gunshot wound to the face from a black powder revolver. Autopsy revealed extensive\\u000a soot and powder deposition around the entrance wound between the right eye and nose with perforation of the skull

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

2010-01-01

19

The effect of pressure on carbon black\\/elastomer powders  

Microsoft Academic Search

Summary Three carbon blacks of the SRF-, HEB- and HCC-1-type as well as powders from spray-dried mixtures of SBR-latex with these carbon blacks and of NBR-latex with HAF-black were subjected to high pressure up to 20 kbar.

G. Angerer; H. Schilling

1975-01-01

20

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

21

9. BUILDING 68. LOADING HOUSE FOR BLACK POWDER COMPONENTS OF ...  

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

9. BUILDING 68. LOADING HOUSE FOR BLACK POWDER COMPONENTS OF MECHANICAL FUZES. FOUNDATION, FLOOR PLAN AND ELEVATIONS. December 10, 1940 - Frankford Arsenal, Building No. 68, Southeast corner of Walbach Street & Benet Road, Philadelphia, Philadelphia County, PA

22

8. BUILDING 68. LOADING HOUSE FOR BLACK POWDER COMPONENTS OF ...  

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

8. BUILDING 68. LOADING HOUSE FOR BLACK POWDER COMPONENTS OF MECHANICAL FUZES. PLANS, ELEVATIONS, SECTIONS, DETAILS December 10, 1940 - Frankford Arsenal, Building No. 68, Southeast corner of Walbach Street & Benet Road, Philadelphia, Philadelphia County, PA

23

The Role of Black Powder in Propelling Charges.  

National Technical Information Service (NTIS)

Plans for converting from batch processing to automated, primarily continuous production of black powder, involving among numerous changes, replacement of the traditional wheel mill by a jet mill, have raised concerns over the possibility of consequent mo...

F. Williams

1975-01-01

24

The Influence of Physical Properties on Black Powder Combustion.  

National Technical Information Service (NTIS)

It has been observed that black powder made from ingredients of the same lot and fabricated using the same manufacturing procedure results in material exhibiting different burning rates. The current study was undertaken to determine if the physical proper...

R. A. Sasse

1981-01-01

25

Nonideal regimes of deflagration and detonation of black powder  

Microsoft Academic Search

The explosive and deflagration properties of black powder differ significantly from those of modern propellants and compositions\\u000a based on ammonium nitrate or ammonium perchlorate. Possessing a high combustibility, black powder is capable of maintaining\\u000a stable combustion at high velocities in various shells, be it steel shells or thin-walled plastic tubes, without experiencing\\u000a deflagration-to-detonation transition. It is extremely difficult to detonate

B. S. Ermolaev; A. A. Belyaev; S. B. Viktorov; K. A. Sleptsov; S. Yu. Zharikova

2010-01-01

26

Here are procedures for handling persistent black-powder contamination  

SciTech Connect

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, gathering, and storage applications. One of two mechanisms creates iron sulfides: chemical reaction of constituents present in the pipeline, usually hydrogen sulfide, or microbial assimilation of chemical constituents in the pipe and the production of both iron sulfides and pipe-wall pitting. The paper describes the sources of black powder, filtering, gas quality, testing, removal, handling, and disposal.

Baldwin, R.M. [Southwest Research Inst., San Antonio, TX (United States). Mechanical and Fluids Engineering Div.

1998-10-26

27

Evaluation of Black Powder Produced by Indiana Army Ammunition Plant.  

National Technical Information Service (NTIS)

Closed-bomb techniques were used to determine quickness and burning-rate equations for two standard class-one black powders made by DuPont and GOEX; these results were compared to similar measurements on material produced by the Indiana Army Ammunition Pl...

R. A. Sasse H. E. Holmes W. P. Aungst J. O. Doali R. E. Bowman

1984-01-01

28

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

29

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2011 CFR

...more than four freight containers may be on board one cargo vessel; (c) The black powder must be packed in inner metal or heavy wall conductive plastic receptacles not over 454 g (16 ounces) net capacity each, with no more than 25 cans...

2011-10-01

30

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2012 CFR

...more than four freight containers may be on board one cargo vessel; (c) The black powder must be packed in inner metal or heavy wall conductive plastic receptacles not over 454 g (16 ounces) net capacity each, with no more than 25 cans...

2012-10-01

31

Preparation of SnO 2 nanoparticles less than 10 nm in size by precipitation using hydrophilic carbon black powder  

Microsoft Academic Search

Tin oxide powder has recently been prepared by a modified precipitation method in which the precipitate is mixed with carbon black powder, a method which offers low cost and mass production. In this study, we prepared tin oxide powder by the modified precipitation method using hydrophilic and non-hydrophilic carbon black powders. When using the hydrophilic carbon black powder, the crystallite

Noriya Izu; Norimitsu Murayama; Woosuck Shin; Toshio Itoh; Ichiro Matsubara

2008-01-01

32

Preparation of NiO nanoparticles as supercapacitor electrode by precipitation using carbon black powder  

Microsoft Academic Search

Nickel oxide nanoparticles were synthesized by a simple aqueous solution method with carbon black powder. x­ ray diffraction analysis shows that the mean size of the synthesized nickel oxide is 8.3 nm, which is much smaller than that obtained from other two methods without carbon black powder annealed at 350°C (21.1 nm) and with carbon black powder annealed at 600°C

Y. E. Chen; Z. N. Yu; Y. G. Chen; L. Q. Luo; X. Wang

2011-01-01

33

Complex suicide with black powder muzzle loading derringer.  

PubMed

Planned complex suicide is defined as the combination of more than one method of suicide, previously planned by the victim, to prevent failure of the first method. Herein, we present a case of planned complex suicide, committed by a black powder muzzle loading handgun and hanging. A 39-year-old man was found dead in the bathroom of his flat, hanging by the neck with a huge atypical gunshot entrance in the right temporal region of his head with extensive backspatter. The skin defects, as well as soft tissues in the subcutaneous pocket undermining, were heavily burnt. Along the wound canal were multiple bone fragments, and at the end of the path at the left temple was an embedded lead ogival projectile with a cross shaped artificial incision at its tip. The hanging was incomplete. There were no fractures of the hyoid bone and laryngeal cartilages. Cervical muscles and vessels were intact. Simon's sign was negative. Signs of asphyxia were not present. This is the first reported case of complex suicide with a black powder derringer and manipulated projectile. PMID:22227791

Hejna, Petr; Šafr, Miroslav; Zátopková, Lenka; Straka, Luboš

2012-01-08

34

Method of pretreating carbon black powder to improve cathode performance and lithium sulfuryl chloride cell including the pretreated carbon black powder  

Microsoft Academic Search

Carbon black powder is pretreated with acetone or methanol prior to cathode fabrication to improve the cathode operating voltage and increase the cathode life of lithium sulfuryl chloride electrochemical cells.

M. Binder; S. Gilman; E. R. Petersen; W. L. Wade Jr; C. W. Walker Jr

1985-01-01

35

Method of Pretreating Carbon Black Powder to Improve Cathode Performance and Lithium Sulfuryl Chloride Cell Including the Pretreated Carbon Black Powder.  

National Technical Information Service (NTIS)

Carbon black powder is pretreated with acetone or methanol prior to cathode fabrication to improve the cathode operating voltage and increase the cathode life of lithium sulfuryl chloride electrochemical cells.

M. Binder C. W. Walker E. R. Petersen W. L. Wade S. Gilman

1983-01-01

36

Method of pretreating carbon black powder to improve cathode performance and lithium sulfuryl chloride cell including the pretreated carbon black powder  

Microsoft Academic Search

Carbon black powder is pretreated with acetone or methanol prior to cathode fabrication to improve the cathode operating voltage and increase the cathode life of lithium sulfuryl chloride electrochemical cells.

M. Binder; C. W. Jr Walker; E. R. Petersen; W. L. Jr Wade; S. Gilman

1983-01-01

37

Method of Pretreating Carbon Black Powder to Improve Cathode Performance and Lithium Sulfuryl Chloride Cell Including the Pretreated Carbon Black Powder.  

National Technical Information Service (NTIS)

Carbon black powder is pretreated with acetone or methanol prior to cathode fabrication to improve the cathode operating voltage and increase the cathode life of lithium sulfuryl chloride electrochemical cells.

M. Binder C. W. Walker E. R. Petersen W. L. Wade S. Gilman

1985-01-01

38

Analysis of black powder by ion mobility-time-of-flight mass spectrometry.  

PubMed

Ion mobility-time-of-flight mass spectrometry (IM-TOFMS) was used to identify and correlate response ions associated with three black powder samples by mass and mobility. Vapors produced by thermal desorption of the black powders were ionized by a (63)Ni source; subsequent response ions were separated and identified using IM-TOFMS. The same response ions were found for each black powder regardless of geographic origin. The most intense mass and mobility peaks were attributed to ionic forms of sulfur allotropes ((32)S(n)(-), where n = 1-5). Vapor samples from GOEX black powder were also analyzed by two stand-alone ion mobility spectrometry systems, yielding an average reduced mobility value (K(o)) of 2.28 +/- 0.02 cm(2) V(-1) s(-1) for black powder across all three instruments. PMID:19947593

Crawford, Christina L; Boudries, Hacene; Reda, Ralph J; Roscioli, Kristyn M; Kaplan, Kimberly A; Siems, William F; Hill, Herbert H

2010-01-01

39

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

Microsoft Academic Search

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

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

1987-01-01

40

TNT Equivalency of Black Powder. Volume I. Management Summary and Technical Discussion.  

National Technical Information Service (NTIS)

The purpose of this investigation was to experimentally determine the maximum output from black powder explosive reactions in terms of airblast overpressure and impulse. The measured pressure and impulse values are compared with those produced by a hemisp...

H. S. Napadensky J. J. Swatosh

1972-01-01

41

Effect of surface free energy of acetylene black powder on air electrode performance  

Microsoft Academic Search

The effects of acetylene black powder surface free energy on air electrode electrochemical performance and lifetime were studied. The acetylene black was immersed in 30% H2O2 at room temperature and the changes of functional groups and surface free energy were investigated by X-ray Photoelectron Spectros-copy (XPS) and powder contact angle (CA). The air electrode performance was characterized by the potential

Xiuqin OU; Shuguang LIU; Guangchuan LIANG; Ying LI; Xiaoke ZHI; Bin HAN

2006-01-01

42

Differences in the microstructure of iron mechanically processed powder alloyed with interstitial and substitutional elements  

SciTech Connect

Mechanically processing iron powder with interstitial and substitutional elements resulted in different microstructures (grain size, rms-strains, and phases) depending upon the alloying composition. Alloying iron powder with substitutional elements (approximately 4 at% Al, Cr, Nb, and Ti) resulted in a microstructure similar to mechanically processed iron powder: grain size ?7nm, local, rms strain ?0.5%, and bcc-Fe nanograins. Small reductions in grain size and increase in rms strain occurred with increasing radius of the substitute alloy atoms. Substitutional atoms were not uniformly distributed throughout the bcc-Fe matrix, but were distributed in clusters within the nanosgrains and/or as a thin coating on the grain boundaries. Alloying iron powder with interstitial elements (4–8 at% C and N) resulted in significantly different microstructures: decrease in grain size and increase in rms-strain occurred with inceasing the interstitial concentration and a bct-Fe nanograin phase developed. Interstitial atoms were also predominately distributed in clusters and/ or in a thin region along or in the grain boundaries of the iron nanograins.

Rawers, J.C.; Krabbe, R.A.; Cook, D.C. (Old Dominion University, Norfolk VA ); Kim, T.H. (Old Dominion University, Norfolk VA )

1997-01-01

43

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

44

Effect of nonionic and ionic surfactants on zeta potential and dispersion properties of carbon black powders  

Microsoft Academic Search

Dispersion of carbon black powders in aqueous medium was investigated by using anionic surfactant sodium oleate and a series of nonionic surfactants which were selected systematically to represent varying degrees of ethoxylation. Single and binary mixtures of the nonionic and ionic surfactants were employed in zeta potential and particle size measurements and a high affinity of surfactants on carbon black

H. Sis; M. Birinci

2009-01-01

45

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

Microsoft Academic Search

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

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

2003-01-01

46

A study on rheological properties of carbon black extended powdered SBR using a torque rheometer  

Microsoft Academic Search

Rheological properties of high abrasion furnace black (HAF, grade N330) extended powdered styrene butadiene rubber (SBR)—(P(SBR\\/HAF)) and HAF extended bale SBR (SBR\\/HAF) with carbon black content (0–70 phr) and aromatic oil content (0–50 phr) at different rotor speeds (40–80 rpm) and mixing temperatures (50–100 °C) were studied. The studies were carried out with a Brabender torque rheometer with a mixing

Anqiang Zhang; Lianshi Wang; Yiyu Zhou

2003-01-01

47

Synthesis of Cordierite by decomposition of metal nitrates on the surface of carbon black powder  

Microsoft Academic Search

Cordierite precursor was obtained through a process, which involved the decomposition of metal nitrates on the surface of\\u000a ultrafine carbon black powder between 100–300°C and the gasification of the carbon black at higher temperature in air. The\\u000a average size of the particles, which were heat-treated at 700°C for 10h, is about 1020 nm, and the specific surface area is\\u000a about

Xie Zhi-yong; Liang Hui; Xu Ming-xia; Xu Ting-xian

2004-01-01

48

Lifting techniques for finger marks on human skin previous enhancement by Swedish Black powder — A preliminary study  

Microsoft Academic Search

An examination was done to investigate whether certain lifting techniques can lift recovered latent fingerprints on human skin surfaces of living subjects. For recovery Swedish Soot powder mixture (Swedish Black) was used.Donors intentionally placed fingerprints on the skin surface of living subjects. Finger marks were then in all cases recovered with Swedish Black powder. The procedure was repeated after 1 h

Matej Trapecar

2009-01-01

49

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

50

A novel zirconocene\\/ultradispersed diamond black powder supported catalytic system for ethylene polymerization  

Microsoft Academic Search

A novel carrier of ultradispersed diamond black powder (UDDBP) was used to support metallocene catalyst. Al2O3 was also used as carrier in order to compare with UDDBP. Supported catalysts for ethylene polymerization were synthesized by two different reaction methods. One way was direct immobilization of the metallocene on the support, the other was adsorption of MAO onto the support followed

Youling Yuan; Li Wang; Linxian Feng; Kang Xu; Jian Shen

2002-01-01

51

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

Microsoft Academic Search

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

J. L. Clayton; T. A. Daws

1989-01-01

52

Frustrated magnetic structure of Y-substituted CePdAl studied by powder neutron diffraction  

NASA Astrophysics Data System (ADS)

CePdAl is a heavy-fermion antiferromagnet with TN = 2.7 K, crystallizing in the ZrNiAl-type structure. The magnetic structure is described by the propagation vector k = (1/2, 0, ?), ? = 0.35, with the cerium magnetic moments aligned along the c-axis. One third of magnetic moments remains disordered due to the geometrical frustration. Specific heat measurements on substituted Ce1-xYxPdAl compounds revealed strong reduction of TN with Y substitution and the antiferromagnetic order vanishes around x = 0.2. To investigate the microscopic details of the changes in the magnetic structure evoked by nonmagnetic ion substitution, we have performed an experiment on the powder neutron diffractometer E6 at HZB on the samples with x = 0.02, 0.06 and 0.1. Measurements showed the magnitude reduction of the ordered cerium moments with Y substitution while the propagation vector and other magnetic structure characteristics remain unchanged.

?ermák, Petr; Hofmann, Tommy; Javorský, Pavel

2011-07-01

53

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

SciTech Connect

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

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

2007-06-05

54

Characterization of SiC nanowires obtained from carbon black powder  

NASA Astrophysics Data System (ADS)

SiC nanowires were obtained by a reaction between vapor silicon and carbon black powder in vacuum at 1200oC. Their structures and properties were studied using X-ray diffraction, high resolution transmission microscopy, HRTEM, and Raman scattering techniques. We show that diameter of sintered nanowires depends on carbon black grade and its history of thermal treatment. SiC nanowires of diameter as small as 10 nm were obtained from graphitized furnace carbon blacks. Chemical composition of nanowires was similar for all samples, but concentration of structural defects varied and depended on carbon black surface properties and surface morphology. Stacking faults and twins dislocations were observed in all specimens and characterized by HRTEM, X-ray diffraction, and Raman spectroscopy.

Wieligor, Monika; Zerda, T. W.

2009-03-01

55

Synthesis of titanium carbide by thermo-chemical methods with TiH 2 and carbon black powders  

Microsoft Academic Search

A new synthesizing method for producing submicron TiC powders was studied by using TiH2 and carbon black powders. It is well known that hydrogen absorption transforms titanium from metal (h.c.p.) to brittle hydride\\u000a (f.c.c.) powders by ball-milling. This research focused on obtaining submicron-sized TiC powders from the ball-milled mixture\\u000a of TiH2 and carbon black by thermal treatment. The hydrogen, carbon,

In-Shup Ahn; Tek-Kyoung Sung; Sung-Yeal Bae; Ho-Jung Cho; Dong-Kyu Park

2006-01-01

56

The explosion of a ship, loaded with black powder, in Leiden in 1807  

Microsoft Academic Search

In 1807 a ship containing 37,000 pounds of black powder exploded in the centre of Leiden. The effects were devastating, resulting in a large number of casualties and an area of 5.5ha (5.5×104m2) completely destroyed. The effects of the explosion were calculated, based on an equivalent amount of 9000kg of TNT, making use of formulas and knowledge derived from detonation

H. J. Reitsma

2001-01-01

57

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

58

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

Microsoft Academic Search

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

Kenjiro Yamada

2000-01-01

59

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

60

Adsorption-chemical activity of finely-dispersed amorphous powders of brown and black boron used in synthesizing metal borides  

Microsoft Academic Search

Kinetic features of adsorption-desorption processes for a nitrogen and oxygen mixture of gases, nitrogen and water vapor at\\u000a the surface of finely-dispersed amorphous powders of brown and black boron used to synthesize metal borides are studied. The\\u000a different adsorption-chemical activity of amorphous brown and black boron powders towards the main components of an air atmosphere\\u000a is determined. It is shown

V. S. Zenkov

2006-01-01

61

Development and Application of SCAR Marker for the Detection of Papaya Seed Adulteration in Traded Black Pepper Powder  

Microsoft Academic Search

The present study reports the development of a specific, sensitive, and reproducible Sequence Characterized Amplified Region (SCAR) marker to detect papaya seed powder adulteration in traded black pepper powder. A putative RAPD marker (449 bp) specific to papaya seed was identified, cloned, and sequenced to design the SCAR primers. This specific SCAR marker could detect the presence of papaya seed

K. Dhanya; S. Syamkumar; B. Sasikumar

2009-01-01

62

A study on the development of a substitution process by powder metallurgy in automobile parts  

Microsoft Academic Search

Powder metallurgy processes using sintering are able to form net-shaped products and have been used widely in the production of automobile parts to improve productivity. However, the toughness of powder products is generally poor because they contain pores. Therefore, forged products are used in parts subjected to severe fatigue loads, but in the case of powder products having high toughness,

G. B Jang; M. D Hur; S. S Kang

2000-01-01

63

Enhancement of green luminescence of ZnO powders by annealing with carbon black  

SciTech Connect

This paper reports the characterization of nanocrystalline ZnO powders synthesized by a precipitation method and annealed with carbon black. The X-ray diffraction (XRD) and Fourier Transformed Infrared (FT-IR) results revealed that the synthesized ZnO powder has the wurtzite structure with absorbed CO{sub 3}{sup -} species on the surface of the ZnO particles. Singly ionized oxygen vacancy (V{sub O}{sup +}) and CO{sub 3}{sup -} species were also perceived from electron paramagnetic resonance (EPR) analysis. The intensity of the EPR signals of CO{sub 3}{sup -} species increased as the amount of carbon increased whereas that of V{sub O}{sup +} did not vary significantly. A green emission at 528 nm for the powders annealed with carbon was observed and a good correlation between the intensity of green emission and the intensity of EPR signals of CO{sub 3}{sup -} was obtained Experimental results suggest that the formation of the free carriers has significant effect on the intensity of the green emission. The mechanism responsible for the green emission enhancement based on the relevance of the observations is discussed.

Hu Yi [Department of Materials Engineering, Tatung University, Taipei, Taiwan (China)], E-mail: huyi@ttu.edu.tw; Chen, H.-J. [Department of Materials Engineering, Tatung University, Taipei, Taiwan (China)

2008-08-04

64

Preparation and properties of powder styrene–butadiene rubber composites filled with carbon black and carbon nanotubes  

Microsoft Academic Search

Carbon nanotubes (CNTs) and carbon black (CB) filled powder styrene–butadiene rubber (SBR) composites were prepared by spray drying of the suspension of CNTs and CB in SBR latex. The powders were sphere like and fine with uniform diameters of 10–15?m. Experimental results showed that the introduction of CNTs into the matrix was beneficial to improve the security of the vulcanization

Xiang-Wen Zhou; Yue-Feng Zhu; Ji Liang

2007-01-01

65

A New Penthrite Grenade Compared to the Traditional Black Powder Grenade: Effectiveness in the Alaskan Eskimos' Hunt for Bowhead Whales  

Microsoft Academic Search

The Alaskan Eskimos catch bowhead whales of the protected Bering-Chukchi-Beaufort Sea stock using old- fashioned weapons and grenades filled with black powder. Killing is sometimes a lengthy process, and in some years relatively large numbers of animals are lost. A new grenade containing the explosive penthrite was developed for the Eskimos' traditional weapons and first tested in the bowhead whale

EGIL OLE ØEN

66

Crystalline structures and intrinsic magnetic properties of ZnTi-substituted hexagonal M-type Ba ferrite powder  

Microsoft Academic Search

Ion-substituted hexagonal M-type Ba ferrites are studied more and more frequently due to their large magnetic anisotropy and\\u000a low production cost. In this study, hexagonal M-type Ba ferrite powder specimens with nominal composition Ba(ZnTi)xFe12?2xO19 (x = 0.0, 0.2, 0.6, 1.0, 1.4) were prepared via a new route by combining a chemical coprecipitation technique with a conventional\\u000a ceramic technique. The magnetic properties and

Ailin Xia; Dexin Du; Pengpeng Li; Yaxin Sun

2011-01-01

67

Synthesis of substituted M- and W-type barium ferrite nanostructured powders by stearic acid gel method  

Microsoft Academic Search

A series of substituted barium ferrites of M-type, Ba(CoTi)xFe12?2xO19, and W-type, BaZn2?yCoyFe16O27, were prepared as nanostructured powders using the stearic acid gel method. Well-crystallized nanocrystalline hexaferrite particles of 10–20 nm have been obtained at temperatures 650–750°C lower than those of other methods. The structures and micrographs of the nanocrystalline materials were characterized by X-ray diffraction and transmission electron microscopy. The

Xiaohui Wang; Dan Li; Lude Lu; Xin Wang

1996-01-01

68

Thermal expansion measurements using x-ray powder diffraction of Tl1223 substituted by molybdenum  

Microsoft Academic Search

Lattice parameters and the volume thermal expansion coefficient, from room temperature down to 80 K, have been calculated for TlBa2Ca2Cu3-xMoxO9-delta with x = 0.0, 0.05, 0.1 and 0.2 using x-ray powder diffraction. The superconducting transition temperature for the prepared samples, determined from electrical resistivity measurements, is suppressed from 122 to 98 K as the Mo content increases from 0.0 to

R. Awad; A. I. Abou-Aly; S. A. Mahmoud; M. ME Barakat

2007-01-01

69

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

2013-07-01

70

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Carbon black, (4-methylphenyl)-modified...Chemical Substances § 721.10150 Carbon black, (4-methylphenyl)-modified...substance identified generically as carbon black,...

2009-07-01

71

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...Chemical Substances § 721.10150 Carbon black, (4-methylphenyl)-modified...substance identified generically as carbon black,...

2013-07-01

72

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

73

Selective Laser Sintering Method Using Titanium Powder Sheet Toward Fabrication of Porous Bone Substitutes  

NASA Astrophysics Data System (ADS)

The present paper investigates the laser sintering of titanium sheets toward the fabrication of porous artificial bones. The novelty lies in the use of a titanium powder sheet mixed with an organic binder and the application of selective laser sintering to the fabrication of a laminated porous structure. Alternating irradiation of Nd: YAG pulses with short scanning paths results in the suppression of distortion of the sintered part as well as enhanced mechanical properties. Under the appropriate conditions identified in the experiment, a bending strength of 63MPa and a Young’s modulus of 1.5GPa are attained when the load is applied parallel to the lamination direction, whereas load vertical to the lamination direction yields 79MPa and 1.8GPa, respectively. The size of pores varies from 200 to 300µm, and the porosity is approximately 65%. These values, other than Young’s modulus, are almost equivalent to those of human bones.

Hayashi, Terutake; Maekawa, Katsuhiro; Tamura, Masashi; Hanyu, Kenichi

74

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

2010-09-24

75

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

Microsoft Academic Search

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

Woo Seok Chin; Dai Gil Lee

2007-01-01

76

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

77

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

78

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

79

Sensitive detection of black powder by a stand-alone ion mobility spectrometer with an embedded titration region.  

PubMed

Sensitive detection of black powder (BP) by stand-alone ion mobility spectrometry (IMS) is full of challenges. In conventional air-based IMS, overlap between the reactant ion O2(-)(H2O)n peak and the sulfur ion peak occurs severely; and common doping methods, providing alternative reactant ion Cl(-)(H2O)n, would hinder the formation of ionic sulfur allotropes. In this work, an ion mobility spectrometer embedded with a titration region (TR-IMS) downstream from the ionization region was developed for selective and sensitive detection of sulfur in BP with CH2Cl2 as the titration reagent. Sulfur ions were produced via reactions between sulfur molecules and O2(-)(H2O)n ions in the ionization region, and the remaining O2(-)(H2O)n ions that entered the titration region were converted to Cl(-)(H2O)n ions, which avoided the peak overlap as well as the negative effect of CH2Cl2 on sulfur ions. The limit of detection for sulfur was measured to be 5 pg. Furthermore, it was demonstrated that this TR-IMS was qualified for detecting less than 5 ng of BP and other nitro-organic explosives. PMID:23621418

Liang, Xixi; Zhou, Qinghua; Wang, Weiguo; Wang, Xin; Chen, Wendong; Chen, Chuang; Li, Yang; Hou, Keyong; Li, Jinghua; Li, Haiyang

2013-04-29

80

Microwave absorption properties of a wave-absorbing coating employing carbonyl-iron powder and carbon black  

NASA Astrophysics Data System (ADS)

To prevent serious electromagnetic interference, a single-layer wave-absorbing coating employing complex absorbents composed of carbonyl-iron powder (CIP) and carbon black (CB) with epoxy resin as matrix was prepared. The morphologies of CIP and CB were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The electromagnetic parameters of CIP and CB were measured in the frequency range of 2-18 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss (RL) using arch method. The effects of CIP ratio, CB content and thickness on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, CIP or CB content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of CIP or CB in composites.

Liu, Lidong; Duan, Yuping; Ma, Lixin; Liu, Shunhua; Yu, Zhen

2010-11-01

81

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

82

Influence of chemical composition, particle size and morphology on the cytotoxic and genotoxic effects of three black toner powders and their dimethylsulfoxide (DMSO) extracts in cultured human epithelial A549 lung cells in vitro  

Microsoft Academic Search

Methods: Three black toner powders and their suspensions were examined by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy in order to determine size, shape, surface structure and elemental composition of individual toner particles. Powder X-ray Diffractometry (XRD) with Cu-Kalpha radiation was used to determine the mineral phases in the toner powders. The bulk contents of selected metals and

Ella Goldenberg; Mathias Könczöl; Reto Gieré; Bernard Grobéty; Albrecht Seidel

83

On the effect of substituting copper powder with cupric salt for the sintering process of W–Cu MIM Parts  

Microsoft Academic Search

This study was carried out for the feasibility of applying the Cu-contained binder to W–Cu MIM parts as the first step for the practical use. To methylcellulose–water solution (conventional binder), cupric salt was added to create the Cu-contained binder. In this experiment, the W–Cu powder mixture was used with the conventional binder and the Cu-contained binder which removed by thermal

Jeong-Keun Lee

2008-01-01

84

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

85

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

PubMed

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

Karhu, R; Anderson, S

2000-11-01

86

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Carbon black, 4-[[2-(Sulfooxy) ethyl...Chemical Substances § 721.10075 Carbon black, 4-[[2-(Sulfooxy) ethyl...substance identified generically as carbon black, 4-[[2-(Sulfooxy)...

2013-07-01

87

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Carbon black, 4-[[2-(Sulfooxy) ethyl...Chemical Substances § 721.10075 Carbon black, 4-[[2-(Sulfooxy) ethyl...substance identified generically as carbon black, 4-[[2-(Sulfooxy)...

2009-07-01

88

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

Microsoft Academic Search

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

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

2008-01-01

89

Avaliação química de substitutos de cacau e estudo sensorial de achocolatados formulados Chemical evaluation of cocoa substitutes and study of formulated chocolate drink powder  

Microsoft Academic Search

Cocoa powder is obtained from cocoa paste. It is prepared with fermented, dried, toasted, grinded and pressed beans (to separate cocoa butter). It can be used to produce chocolate powders, which contains cocoa powder, sugar, chocolate flavor and other ingredients. In the major producing countries, the price of cocoa by-product is affected by the climate, plagues and political factors. Cocoa

Magda Leite; Suzana Caetano da Silva

90

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

91

Effect of Cu2+ and Ni2+ substitution at the Mn site in (La0.63Ca0.37)MnO3: A neutron powder diffraction investigation  

NASA Astrophysics Data System (ADS)

The crystal and magnetic structures of the (La0.63Ca0.37)(Mn1-xTMx)O3 compounds (x=0.00, 0.03, 0.08; TM=Cu2+, Ni2+) were investigated between 5 K and 300 K by means of dc magnetic measurements and neutron powder diffraction analysis followed by Rietveld refinement. Both substituting cations lead to a reduction of the long range ferromagnetic ordering temperature; ferromagnetism is strongly suppressed in the 8% Cu-substituted sample, where long- and short-range FM magnetic orders coexist together with short-range A-type AFM order. This particular feature can be related to the Jahn-Teller character of Cu2+, absent in Ni2+, and suggests the occurrence of a quantum critical point in the (La0.63Ca0.37)(Mn1-xCux)O3 system.

Martinelli, A.; Ferretti, M.; Castellano, C.; Cimberle, M. R.; Ritter, C.

2013-04-01

92

Improving the electrical conductivity by forming Ni powder chains in a shape-memory polymer filled with carbon black  

NASA Astrophysics Data System (ADS)

We demonstrate a simple approach to significantly reduce the electrical resistivity of thermo-responsive shape-memory polymers (SMPs), so that they can be easily triggered for shape recovery by Joule heating at a low electrical voltage. After adding a small amount of Ni micro particles into a polyurethane SMP filled with carbon black (CB), the electrical resistivity is slightly reduced. However, if these Ni particles are aligned into chains (by applying a low magnetic field on SMP/CB/Ni solution and then drying to fix the conductive chains), the drop of electrical resistivity is significant. This kind of SMP composites is suitable for cyclic operation as only micro/nano particles are used. A sample (40×15×1mm) with 10vol% of CB and 0.5vol% of chained Ni can be heated to 80°C for shape recovery at 30 V (1.2 W) of power. This approach is generic and applicable for producing other conductive polymers.

Lan, Xin; Huang, Wei Min; Liu, Na; Phee, Sy; Leng, Jin Song; Du, Shan Yi

2008-05-01

93

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

94

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

95

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

96

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

97

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

98

Mystery Powders  

NSDL National Science Digital Library

In this activity on page 2 of the PDF, learners conduct chemical tests on certain powders used in cooking. After completing the tests, learners try to figure out the identity of a mystery powder. Learners record their observations on a chart. Note: you will need an adult helper for this activity.

Society, American C.

2000-01-01

99

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

100

Powder Particulars  

NSDL National Science Digital Library

In this introductory activity and demonstration, learners are introduced to the concept that different substances react chemically in characteristic ways. First learners compare the way baking soda and baking powder react with vinegar. Then they see dramatic color changes when red cabbage indicator is added to cream of tartar and laundry detergent. From this, learners are ready to identify unknown powders based on their reactive properties.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

101

Benzene Substitutes.  

National Technical Information Service (NTIS)

The document identifies the most important potential benzene substitutes, determines their use in consumer products, and reviews the toxicology of these substances. The major benzene substitutes-cyclohexane, methylene chloride, and xylene, as well as ethy...

A. Mazella R. L. Malseed S. Scott S. Hunsicker D. Shellenberger

1978-01-01

102

Blood Substitutes  

Microsoft Academic Search

\\u000a Blood substitutes have been developed to replace the transfusion of banked blood. Actually, it is unlikely that one singular\\u000a infusion fluid will ever replace all functions of whole blood. Indeed, “blood substitutes” merely substitute the O2-carrying function of red blood cells (RBC), so these substances should rather be referred to as “oxygen carrying blood substitutes”\\u000a or as “artificial oxygen carriers.

Andreas Pape; Oliver Habler

103

Substitute Solutions.  

ERIC Educational Resources Information Center

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

Jones, Kevin R.; Hawkins, Amber

2000-01-01

104

Blood substitutes.  

PubMed Central

With the development of modern methods of surgery, anaesthesia, and pre- and postoperative care the requirement for blood substitutes is continuously increasing. We present a review of the different blood substitutes which are already in clinical use or in an advanced stage of experimental investigation for possible practical administration. Our own clinical experience with dextrans and experimental studies on stroma-free haemoglobin and hydroxyethyl starch solutions are described.

Kostrzewska, E.

1976-01-01

105

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

106

Reactive PZT precursor powder by coprecipitation  

Microsoft Academic Search

Lead, zirconium and titanium were coprecipitated from their aqueous salt solutions using oxalic acid. The precipitate on heating to 850 °C gave phase pure PZT powder which showed good sinterability. The average grain size in the pellets sintered at 900 °C for 6 h was about 1 ?m. Barium and strontium were found to coprecipitate with lead facilitating partial substitution.

K. Rama Mohana Rao; A. V. Prasada Rao; S. Komarneni

1996-01-01

107

Solvent substitution  

SciTech Connect

The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

Not Available

1990-01-01

108

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

109

Sensory Substitution  

NASA Astrophysics Data System (ADS)

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

Verrillo, Ronald T.

110

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

111

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

112

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

113

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

114

Preparation of titanium diboride powder  

DOEpatents

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

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

1985-01-01

115

Coffee substitute  

US Patent & Trademark Office Database

A coffee-type beverage base is prepared by light roast method under 200.degree. C. and originated from grain and legume. This coffee substitute has a pleasant aroma, and can be used as a carrier of nutritional supplement or herb therapy as well as an additive of coffee, tea, or chocolate. This novel drink is especially suitable for individuals who suffer from conditions making them coffee intolerant, e.g., pregnancy, or those who suffer form hypoglycemia, hypertension, arrhythmia, insomnia, or gastric irritation.

2001-01-09

116

Structural and magnetic characterisation of CoSb{sub 2}O{sub 4}, and the substitution of Pb{sup 2+} for Sb{sup 3+}  

SciTech Connect

The nuclear and magnetic structures of the synthetic schafarzikite related material CoSb{sub 2}O{sub 4} have been determined from neutron powder diffraction data. The compound is tetragonal (P4{sub 2}/mbc) with refined lattice constants at 300 K of, a=8.49340(9) A, c=5.92387(8) A. The magnetic ordering is shown to be consistent with a C mode with moments aligned along [0 0 1]. Magnetic susceptibility measurements indicate a canted antiferromagnetic ground state, for which the ferromagnetic component shows unusually high coercivity. The thermal stability of CoSb{sub 2}O{sub 4} in air is reported. The substitution of Pb{sup 2+} for Sb{sup 3+} has been investigated and found to cause oxidation of both Co{sup 2+} to Co{sup 3+} and Sb{sup 3+} to Sb{sup 5+}. - Graphical Abstract: Structural changes on substitution of Pb{sup 2+} ions for Sb{sup 3+} ions in CoSb{sub 2}O{sub 4}. Highlights: Black-Right-Pointing-Pointer The structural details of CoSb{sub 2}O{sub 4} are reported for the first time. Black-Right-Pointing-Pointer The magnetic structure of CoSb{sub 2}O{sub 4} are reported for the first time. Black-Right-Pointing-Pointer The ordered magnetic structure has a canted antiferromagnetic arrangement. Black-Right-Pointing-Pointer The ferromagnetic component of the ordered arrangement has high coercivity. Black-Right-Pointing-Pointer Pb{sup 2+} can substitute for Sb{sup 3+} and oxidation of both Co{sup 2+} and Sb{sup 3+} occurs.

Laune, Benjamin P. de [School of Chemistry, University of Birmingham, Birmingham B15 2TT (United Kingdom); Greaves, Colin, E-mail: c.greaves@bham.ac.uk [School of Chemistry, University of Birmingham, Birmingham B15 2TT (United Kingdom)

2012-03-15

117

Substitution therapy for heroin addiction.  

PubMed

Substitution treatment for heroin addiction, defined here as maintenance prescribing of opioid agonist drugs to opioid dependent subjects, has increased in the last decade. The recent history of substitution treatment in five countries--Canada, the U.K., Australia, Israel, and France--is reviewed. In all five countries, the critical issues around substitution treatment are similar. The first key issue concerns the balance between making treatment accessible and attractive, and minimizing diversion to the black market. The second issue concerns the role of primary health care in delivering MMT. In general, there has been increasing involvement of primary health care, with training and support for practitioners. However, there remains uncertainty and official ambivalence over whether treatment should be restricted to specialist clinics and practitioners, or available through primary care. Most importantly, underlying these issues is the problem of stigma being associated with both addiction, and with substitution treatment. The underlying problem that treatment is often at odds with community values places enormous strains on substitution treatment, and makes the treatment system vulnerable to shifting community support and abrupt, politically-driven changes in policy. PMID:12180559

Bell, James; Dru, Alain; Fischer, Benedikt; Levit, Shabtay; Sarfraz, M Aamer

118

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

119

Microbially mediated synthesis of metal-substituted magnetic nanoparticles  

Microsoft Academic Search

Synthetic or substituted powder magnetites are generally prepared by solid phase reaction or by wet chemical methods. The objective of this study is to examine biologically facilitated production of copious amounts of extracellular metal-substituted magnetite nanoparticles. The microbially mediated synthesis of metal-substituted magnetites by Tberoanaerobacter ethanolicus (TOR-39, C1) isolated from a deep subsurface environment was investigated under anaerobic conditions. The

Y. Rob; R. J. Lauf; C. J. Lauf; S. M. Pfiffner; A. V. Palumbo; T. J. Phelps

2003-01-01

120

Dustiness of fine and nanoscale powders.  

PubMed

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 300 nm to several micrometers, but no modes below 100 nm, were observed. It is therefore unlikely that these materials would exhibit a substantial sub-100 nm particle contribution in a workplace. PMID:23065675

Evans, Douglas E; Turkevich, Leonid A; Roettgers, Cynthia T; Deye, Gregory J; Baron, Paul A

2012-10-12

121

Talcum Powder and Cancer  

MedlinePLUS

... is talcum powder? Talcum powder is made from talc, a mineral made up mainly of the elements ... other consumer products. In its natural form, some talc may contain asbestos, a substance known to cause ...

122

Precision powder feeder  

DOEpatents

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

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

2001-07-10

123

Smokeless Powder Manufacture.  

National Technical Information Service (NTIS)

The smokeless powder propellants are suitable for propelling military rockets and actuating jet devices such as assisted takeoff motors for airplanes. Smokeless powder granules are introduced into a container, pressure is placed on the granules and nonvol...

D. H. Black

1965-01-01

124

Atomized copper powders  

Microsoft Academic Search

For the first time in the Soviet Union pilot-plant batches of copper powder have been produced by the method of atomization of melts with water under high pressure. The powder produced is characterized by increased apparent density and flowability. The best compressibility (2–6 tons\\/cm2) is exhibited by the powder after annealing. The compressibility of the powder in the as-atomized condition

A. N. Karibyan; A. B. Medvedovskii; V. A. Belyakov; N. S. Sarkisyan; N. G. Dyuzhakova; O. S. Nichiporenko; V. T. Aivazyan; V. P. Poteshkina; Yu. I. Naida

1981-01-01

125

Black Holes  

NSDL National Science Digital Library

This work discusses the fundamental ideas about black holes. There is information about black holes, creative activities to use in a classroom, and ideas about how to relate this material to popular science fiction novels.

Pacific, Astronomical S.

2004-07-17

126

Black Magic  

NSDL National Science Digital Library

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

2010-01-01

127

Black Holes  

NSDL National Science Digital Library

This website contains a list of Frequently Asked Questions about Black Holes. The goal is to answer the common, and not so common, doubts about Black Holes, such as their origin, properties, and fate. It also deals with gravitational effects of Black Holes, and the concepts of White Holes and Wormholes.

Bunn, Ted

2007-06-05

128

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.

129

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

130

Which Powder is It?  

NSDL National Science Digital Library

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

Sciencenter

2012-06-26

131

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

132

Black Smokers  

NSDL National Science Digital Library

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

133

The powder dilemma  

SciTech Connect

This article examines the high Tc powder market. Two types of suppliers are distinguished: large materials suppliers and small start-up superconductor firms. The author analyzes the role each is playing in the present market and discusses future possibilities for both. The problem of a lack of standards for high Tc powder is addressed.

Carlson, L

1989-01-01

134

Compaction of Titanium Powders  

Microsoft Academic Search

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 mum, <75 mum, and < 45 mum; two

Stephen J. Gerdemann; Paul D. Jablonski

2011-01-01

135

Sinterability of titanium powder  

Microsoft Academic Search

The sintering process of compacts from dispersed titanium powders (as well as from metal powders with easily reducible oxides) is accomplished in two stages — a nonsteady stage with a high densification rate and a steady stage, whose rate is determined by volume diffusion. The low values of energy of activation for densification in the first stage of sintering may

D. S. Arensburger

1970-01-01

136

Black Holes  

NSDL National Science Digital Library

The first website (1), created by the Department of Physics at Syracuse University, provides an educational, easily understandable explanation of the characteristics of a black hole. Students can learn the consequences a spacecraft would face if it traveled near or through the horizon of a black hole. The next website (2 ), created by the Amazing Space education group of the Space Telescope Science Institute's Office of Public Outreach, provides an online interactive exploration of black holes. Through this large, vibrant website, students can learn about stellar, supermassive, and miniature black holes. Teachers can find many amazing images, lesson plans, and other scientific background information. NASA created the next website (3) as a directory to many websites discussing black holes. Visitors can listen to the sound of a black hole, ask a NASA scientist questions, take a journey into a Black Hole, and much more. Wikipedia (4) investigates the questions related to how classical theories of thermodynamics are upheld within black holes. Students and educators will find links for many of the physical terms used within the descriptions to obtain further information. Robert M. Wald at the University of Chicago discusses Hawking radiation, the generalized second law, the thermodynamics of black holes, and entropy (5). This more advanced description provides numerous references and equations, as well as a discussion on issues the author feels are unresolved. J.E. Avron at the Israel Institute of Technology provides a straightforward discussion of the thermodynamics and entropy of black holes for those not familiar with the theory of general relativity (6). Through this pdf document, students can learn about the Planck scale, the temperature of black holes, and the LaPlace argument. The last two websites are online news articles describing the latest developments of black holes. After a fifty-three hour observation, NASA scientists have concluded that the central region of the Perseus galaxy cluster is producing sound waves with a frequency over a million billion times lower than the limits of human hearing (7). After learning how these sound waves are thought to have been created, visitors can view an animation of the waves generated in the Perseus Cluster. The last website (8), provided by space.com, investigates the question "If I had the opportunity to look at a black hole, would it look like a hole all the way around or just a hole above and below a funnel?" Visitors can also learn the about the spinning of black holes.

137

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 ?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.

Stephen J. Gerdemann; Paul D. Jablonski

2010-11-01

138

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

139

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

140

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

141

Super Chi Flush Powder  

Center for Drug Evaluation (CDER)

Text Version... Chi Flush Powder “Super Chi Flush fights the toughest clogs in the body slowly opening up the blockades which hindered the flow of Chi energy. ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

142

Aluminum powder metallurgy processing.  

National Technical Information Service (NTIS)

The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from a...

J. F. Flumerfelt

1999-01-01

143

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

144

Compaction of Titanium Powders  

Microsoft Academic Search

Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts\\u000a were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods.\\u000a In this work, eight different titanium powders (three different sizes of sponge fines ?m, ?m, and ?m; two different sizes of a hydride-dehydride

Stephen J. Gerdemann; Paul D. Jablonski

2011-01-01

145

Black Holes  

NSDL National Science Digital Library

This presentation describes the problems associated with Newton's theory of gravity and then briefly outlines the key features of Einstein's theory of general relativity. The remainder of the notes focus on black holes: their definition, properties, and most importantly how they are observed in nature. Finally it describes why black holes are so important to theoretical physicists, and in what sense they are posing riddles whose resolution will point the way to a viable theory of quantum gravity.

Kunstatter, G.

2005-06-07

146

Powders for metal injection molding  

Microsoft Academic Search

Metal injection molding (MIM) uses powders which differ considerably from the ceramics powders used for ceramic injection molding. Metal powders are hardly available in the sub-micron ranges that are almost standard in ceramics. The reason for this lies in the ductility and reactivity of the metals which make it difficult and very expensive to produce fine powders. In this paper

T. Hartwig; G. Veltl; F. Petzoldt; H. Kunze; R. Scholl; B. Kieback

1998-01-01

147

What is "powder free"? Characterisation of powder aerosol produced during simulated use of powdered and powder free latex gloves  

PubMed Central

OBJECTIVES—To characterise the distribution of particle size and mass of glove powder aerosol released from powdered and powder free non-sterile latex gloves under controlled conditions.?METHODS—Gravimetric sampling and aerodynamic particle size analysis were performed during simulated use of gloves on a prosthetic hand in a chamber designed to minimise background particle concentrations.?RESULTS—Aerosol was detectable for both powdered and powder free gloves under both aggressive and non-aggressive handling conditions. Most of the particles detected had aerodynamic diameter less than 10 µm.?CONCLUSION—Powder free gloves were not entirely free of powder aerosol. Particles from both powdered and powder free gloves are sufficiently fine to penetrate into the thoracic region of the respiratory tract.???Keywords: latex gloves; glove powder; aerosol

Phillips, M; Meagher, C; Johnson, D

2001-01-01

148

Black Holes in Higher Dimensions (black Strings and Black Rings)  

NASA Astrophysics Data System (ADS)

Higher dimensional black holes received much interest in recent years, in particular in the context of string theory, and with the advent of brane-world theories, raising the possibility of direct observation in future high energy colliders. This session on black holes in higher dimensions features predominantly contributions on black holes, on black rings, on caged black holes, and on uniform and non-uniform black strings. Further topics are solitons in higher dimensions, gravitational collapse, etc.

Kunz, Jutta

2008-09-01

149

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

150

Thermal properties of carbon black aqueous nanofluids for solar absorption  

NASA Astrophysics Data System (ADS)

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.

Han, Dongxiao; Meng, Zhaoguo; Wu, Daxiong; Zhang, Canying; Zhu, Haitao

2011-07-01

151

Thermal properties of carbon black aqueous nanofluids for solar absorption.  

PubMed

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. PMID:21767359

Han, Dongxiao; Meng, Zhaoguo; Wu, Daxiong; Zhang, Canying; Zhu, Haitao

2011-07-18

152

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

153

The Thermochromic Vanadium Dioxide I. Role of Stresses and Substitution on Switching Properties  

Microsoft Academic Search

The monoclinic tetragonal transition occurring at 341 K for VO2 vanadium dioxide and the corresponding switching of the optical properties can be affected in various ways by thermal treatments, substitution, and pressure. The transition in pure or substituted powdered samples is characterized by thermal analysis (DSC), X-ray (XRD) and neutron (NRD) diffractions, and infrared spectroscopy (IR). The influence of pressure

J. C. Rakotoniaina; R. Mokrani-Tamellin; J. R. Gavarri; G. Vacquier; A. Casalot; G. Calvarin

1993-01-01

154

Acoustic properties of organic powders as ultrasonic contrast agents  

NASA Astrophysics Data System (ADS)

The results of experiments on measuring attenuation and the effective acoustic nonlinear parameter of the second order are given for a suspension of cocoa-powder in water at different concentrations of the suspension. In the process of evaluating the value of the nonlinear parameter the attenuation in the suspension and generation of the second harmonic not only in the suspension but also in water are taken into account. The obtained results are evidence of the possibility of using a suspension of cocoa-powder in water as a technical substitute for ultrasonic contrast agents. The values of attenuation (up to 60 m-1 at the concentration of 1 g of the powder per 1 l of water) and the nonlinear parameter (up to 120 m-1 at the same concentration) mean that the suspension of cocoa-powder in water has smaller attenuation and the nonlinear parameter than ultrasonic contrast agents at the same concentration. However, these values for the suspension differ considerably from corresponding values for water or blood and, therefore, a suspension of cocoa-powder in water is a promising "substitute" for ultrasonic contrast agents in the case of technical testing of systems for nonlinear tomography of a blood flow, but cannot replace them in medical studies.

Burov, V. A.; Loginov, S. V.; Dmitriev, K. V.

2011-11-01

155

[Opiate substitution: the users' point of view].  

PubMed

The needs of drug users for substitution therapy and drug-use-related care can vary greatly, a source of conflict between users and health care professionals and sometimes generating dysfunction of the health care system. For example, in France the lack of injection formulations for substitution therapy has led users to inject their substitution product (Subutex or Skenan) creating a bogus relationship with the pharmacist or physician who do not know how they should react. Beliefs held by health care professionals and the lack of drug abuse training in the pharmacy and medicine curricula can also lead to a dangerous situation for users: physicians may prescribe a dose too low for substitution with the risk of pushing the user into the black market to search for a complement. We detail here the way users would like to use substitution, focusing on the points where they are in agreement or disagreement with health care professionals. We explain why, in our opinion, it is fundamental to take into consideration the users' point of view. PMID:19695373

Chappard, P

2009-07-31

156

Review of Bone Substitutes  

PubMed Central

Bone substitutes are being increasingly used in craniofacial surgery and craniomaxillofacial trauma. We will review the history of the biomaterials and describe the ideal characteristics of bone substitutes, with a specific emphasis on craniofacial reconstruction. Some of the most commonly used bone substitutes are discussed in more depth, such as calcium phosphate and hydroxyapatite ceramics and cements, bioactive glass, and polymer products. Areas of active research and future directions include tissue engineering, with an increasing emphasis on bioactivity of the implant.

Pryor, Landon S.; Gage, Earl; Langevin, Claude-Jean; Herrera, Fernando; Breithaupt, Andrew D.; Gordon, Chad R.; Afifi, Ahmed M.; Zins, James E.; Meltzer, Hal; Gosman, Amanda; Cohen, Steve R.; Holmes, Ralph

2009-01-01

157

The Black President Hokum  

Microsoft Academic Search

By offering a black feminist critique of fictional black presidencies, this essay highlights what the trope of black presidency, articulated via competing narratives of time and historical progress, is meant to manage in contemporary U.S. public culture: a heterogeneous black freedom struggle that is both conjured and contained by the trope of the black president, the objections of black women

Erica R. Edwards

2011-01-01

158

The Black President Hokum  

Microsoft Academic Search

:By offering a black feminist critique of fictional black presidencies, this essay highlights what the trope of black presidency, articulated via competing narratives of time and historical progress, is meant to manage in contemporary U.S. public culture: a heterogeneous black freedom struggle that is both conjured and contained by the trope of the black president, the objections of black women

Erica R. Edwards

2011-01-01

159

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

160

FORGING BERYLLIUM POWDER  

Microsoft Academic Search

The developments and results obtained in press forging beryllium powder ; are described. The forging method consists of using pressures in the range of ; 20,000 to 100,000 psi, sintering times from l sec to l min, and two temperature ; ranges of l600 and 1900 deg F. The description of a nonberyllium (stainless ; steel) can fabricated for holding

Cieslicki

1962-01-01

161

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

162

Electrically conductive ceramic powders  

NASA Astrophysics Data System (ADS)

Electrically conductive ceramic powders were investigated in this project. There are three ways to produce those materials. The first is doping alkali metal into the titanium dioxides in an inert or reducing atmosphere. The second is reducing un-doped titanium dioxide, forming a non-stoichiometric composition in a hydrogen atmosphere. The third is to coat a conductive layer, reduced titanium dioxide, on an insulating core such as alumina. Highly conductive powders have been produced by all these processes. The conductivity of powder compacts ranged between 10-2 and 10° S/cm. A novel doping process was developed. All samples were doped by a solid-vapor reaction instead of a solid state reaction. Titanium dioxide was doped with alkali metals such as Na or Li in this study. The alkali metal atom contributes an electron to the host material (TiO2), which then creates Ti 3+ ion. The conductivity was enhanced by creating the donor level due to the presence of these Ti3+ ions. The conductivity of those alkali doped titanium oxides was dependent on the doping level and charge mobility. Non-stoichiometric titanium oxides were produced by reduction of titanium dioxide in a hydrogen atmosphere at 800°C to 1000°C for 2 to 6 hours. The reduced titanium oxides showed better stability with respect to conductivity at ambient condition when compared with the Na or Li doped samples. Conductive coatings were prepared by coating titanium precursors on insulating core materials like SiO2, Al2O3 or mica. The titania coating was made by hydrolysis of titanyl sulfate (TiOSO 4) followed by a reduction procedure to form reduced titanium oxide. The reduced titanium oxides are highly conductive. A uniform coating of titanium oxides on alumina cores was successfully produced. The conductivity of coated powder composites was a function of coating quantity and hydrolysis reaction temperature. The conductivity of the powder as a function of structure, composition, temperature, frequency and moisture was studied. Three classifications of structure were identified for alkali-doped titanium oxides: (1) Pure titanium dioxide phase with alkali ions located in interstitial positions. (2) The titanium bronze phases. (3) Alkali-doped titanium oxides. Highly conductive powders were obtained in the first and second classifications with conductivity of 10-2 to 10° S/cm. Materials in the third classification had poor conductivity below 10-3 S/cm. The conductivity of a powder was determined mainly by the grain conductivity and the grain contact conductivity. The present results of impedance spectroscopy suggested that the grain contact resistance was a major factor of the electrical resistance of the samples. The aging effect at different moisture conditions was also caused by an increase of the contact resistance. Both sodium-doped and reduced titanium oxides showed re-oxidation at elevated temperature (above 140°C) in air, which is most probably caused by oxidizing the Ti3+ ions under those conditions. Lithium doped titanium oxides did not show this re-oxidation at temperatures up to 200°C. Theoretical models were applied to describe the effects of porosity, contact configuration and grain surface on conductivity of powder compacts. Percolation theory was used in the present study to demonstrate the effect of mixtures of conductive and non-conductive powders, which is one of applications for conductive ceramic powders when they are used as filler materials in paper, paints or plastics.

Lu, Yanxia

1999-11-01

163

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

164

Black Flies  

NSDL National Science Digital Library

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

0002-11-30

165

Bismuth substituted calcium, strontium, and lead apatites  

NASA Astrophysics Data System (ADS)

Bismuth substituted apatites of two general types have been prepared: M10-2xBixNax(PO4)6Y2 (M = Ca, Sr, Pb; Y = F, Cl) and lead apatites with the Y ion completely vacant Pb10-(2x+2)BixNax+2(PO4)6. X-ray powder diffraction patterns of all the compounds show the P63/m hexagonal apatite type structure. The change of the lattice parameters and c/a values with compositions indicate the preference of the bismuth ions to occupy the 6h triangular positions. Bi3+ tends to incorporate in apatites with unoccupied halide positions.

Mayer, I.; Semadja, A.

1983-03-01

166

Thin Steel Strip from Powder.  

National Technical Information Service (NTIS)

A process for rolling thin strip is described which overcomes the disadvantages normally associated with powder rolling. Strip samples were made from both iron and stainless steel powders and an experimental plant has been built for continuous strip produ...

I. Davies W. M. Gibbon A. G. Harris

1969-01-01

167

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

168

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

169

The study of preparation of AlN powder  

Microsoft Academic Search

Highly purified fine AlN powder was synthesized with low oxygen content. The optimal raw materials were Al2O3 dehydrated from Al(OH)3, carbon black, and AlN seed crystal, and their weight proportion was 1:0.5:0.01, respectively. Appropriate addition of AlN seed crystals might make the product finer. The order of the reaction was zero whose rate constants were 0.23 mol\\/L-s at 1400°C and

D. F. Qian; Z. D. Xiong

1991-01-01

170

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

171

Powder compaction with ultrasonic assistance  

Microsoft Academic Search

The compaction behaviour of a ceramic powder can be improved by ultrasonic assistance, only when ultrasounds are used at pressures lower than a critical value,PC. This critical pressure is connected with the limit of mobility of the powder grains under ultrasonic vibrations. Its value depends on the characteristics of the powder, as well as those of the ultrasounds: frequency, amplitude,

E. Emeruwa; J. Jarrige; J. Mexmain; M. Billy; K. Bouzouita

1990-01-01

172

Powder metallurgy of superalloys  

SciTech Connect

Powder metallurgy superalloys were developed in the mid-1960's when stronger aircraft turbine disk materials were needed. Their characteristics of greatly reduced segregation, better hot-workability, improved mechanical properties, and cost-effective manufacturing processes made P/M superalloys highly desirable in high-temperature applications. This book deals with prealloyed superalloys including rapidly solidified (RSR) alloys and oxide-dispersion strengthened alloys, as well as processing techniques such as sintering, hot isostatic pressing, extrusion, and isothermal forging. The large range of microstructures possible are correlated with mechanical properties at intermediate and elevated temperatures. Methods of powder production and consolidation are detailed, as are thermomechanical processing principles by which different microstructures can be created. Non-destructive testing techniques, and problems and advances relating to mechanical properties and processing are also covered.

Gessinger, G.H.

1984-01-01

173

Powder metallurgy of superalloys  

Microsoft Academic Search

Powder metallurgy superalloys were developed in the mid-1960's when stronger aircraft turbine disk materials were needed. Their characteristics of greatly reduced segregation, better hot-workability, improved mechanical properties, and cost-effective manufacturing processes made P\\/M superalloys highly desirable in high-temperature applications. This book deals with prealloyed superalloys including rapidly solidified (RSR) alloys and oxide-dispersion strengthened alloys, as well as processing techniques such

Gessinger

1984-01-01

174

Powder characteristics and coating conditions of fresh and reused polyester resins for electrostatic powder coating: powder recycling and loss prevention  

Microsoft Academic Search

Powder characteristics and coating conditions are significant factors in electrostatic powder coating. In this work, powder characteristics of the reused polyester resin or recycled powder particles in terms of shape, size, particle size distribution, moisture content, density, flowability, fluidity and chargeability were compared with those of fresh resin or as-received powder to consider powder recycling. The coating conditions for a

A. W. Lothongkum; R. Nonthapone; K. Seangkiatiyuth; W. Tanthapanichkoon

2007-01-01

175

Structure and Properties of Manganese-Substituted Bismuth Titanates  

NASA Astrophysics Data System (ADS)

Partial substitution of manganese for titanium in bismuth titanate is a potential method to introduce ferromagnetic properties to ferroelectric bismuth titanate. We have established that manganese-substituted bismuth titanate forms only at low manganese contents. As the manganese content is increased, secondary phases form. A combination of neutron and synchrotron X-ray powder diffraction has been used to determine the structure of manganese-substituted bismuth titanates with chemical composition Bi4MnxTi3_xO12 (0 <= x <=1 at 0.05 steps). Measurements between 4 K and 1073 K have been used to examine the phase transitions that they undergo. It was found the substitution of manganese into bismuth titanate increases the phase transition temperature to tetragonal by about 100 °C. Neutron diffraction and bulk magnetic susceptibility measurements demonstrate the absence of long-range magnetic cation ordering in selected examples.

Ting, J.; Kennedy, B. J.

2010-11-01

176

Black powder drugs: an innovative response to drug control policy  

Microsoft Academic Search

As the intensity of the War on Drugs escalates, the social control of drug interdiction crosses international borders and employs more technologically advanced detection and apprehension tactics. In response to this intensification, drug traders develop advanced counter-surveillance strategies that diminish their chances of being detected and apprehended. This results in an interesting relationship between those who choose to indulge in

Christopher P. Krebs; Michael T. Costelloe; David Jenks

2000-01-01

177

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

178

Silicon nitride/silicon carbide composite powders  

DOEpatents

Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

Dunmead, Stephen D. (Midland, MI); Weimer, Alan W. (Midland, MI); Carroll, Daniel F. (Midland, MI); Eisman, Glenn A. (Midland, MI); Cochran, Gene A. (Midland, MI); Susnitzky, David W. (Midland, MI); Beaman, Donald R. (Midland, MI); Nilsen, Kevin J. (Midland, MI)

1996-06-11

179

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

180

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

181

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

182

Physician Substitutes (update)  

Center for Biologics Evaluation and Research (CBER)

Text Version... 1. The physician substitute must be a graduate of a recognized educational program such as nursing, emergency technician or physician assistant ... More results from www.fda.gov/downloads/biologicsbloodvaccines/guidancecomplianceregulatoryinformation

183

Interfacial and conductive properties of liquid marbles coated with carbon black  

Microsoft Academic Search

Liquid marbles coated with carbon black are reported first. Carbon black is a strongly hydrophilic material; an energetic reasoning for coating water drops with the hydrophilic powder is supplied. The shape of marbles is well-described by the oblate spheroid model. The effective surface tension of the marbles is reported. The factors exerting an influence on the effective surface tension of

Edward Bormashenko; Roman Pogreb; Albina Musin; Revital Balter; Gene Whyman; Doron Aurbach

2010-01-01

184

One-Step Hydrothermal-Electrochemical Route to Carbon-Stabilized Anatase Powders  

NASA Astrophysics Data System (ADS)

Black carbon-stabilized anatase particles were prepared by a simple one-step hydrothermal-electrochemical method using glucose and titanium citrate as the carbon and titanium source, respectively. Morphological, chemical, structural, and electrochemical characterizations of these powders were carried out by Raman spectroscopy, Fourier-transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy, and cyclic voltammetry. It was revealed that 200-nm carbon/anatase TiO2 was homogeneously dispersed, and the powders exhibited excellent cyclic performance at high current rates of 0.05 V/s. The powders are interesting potential materials that could be used as anodes for lithium-ion batteries.

Tao, Ying; Yi, Danqing; Zhu, Baojun

2013-04-01

185

Black Smokers  

NSDL National Science Digital Library

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

2009-07-01

186

Why Black-on-Black Homicide?  

ERIC Educational Resources Information Center

|The causes of homicides committed against Blacks by Blacks are examined. Major preventive measures are said to be equal opportunity, better jobs, reduction of racial discrimination, elimination of organized crime, removal of drugs from community, and better schools. (JCD)|

Jeff, Morris F. X., Jr.

1981-01-01

187

Why Black-on-Black Homicide?  

ERIC Educational Resources Information Center

The causes of homicides committed against Blacks by Blacks are examined. Major preventive measures are said to be equal opportunity, better jobs, reduction of racial discrimination, elimination of organized crime, removal of drugs from community, and better schools. (JCD)

Jeff, Morris F. X., Jr.

1981-01-01

188

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

189

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

190

What Is This Black in Black Diaspora?  

Microsoft Academic Search

Looking back at the dialogue between Black British Cultural Studies and African American Studies that occurred during the 1980s and 1990s, when Stuart Hall first asked the question, “What is this black in black popular culture?” this article explores how that conversation has evolved in the context of current discussions of black cross-culturality and diaspora. New concerns have emerged about

Michelle Stephens

2009-01-01

191

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

192

The substitutability of reinforcers.  

PubMed

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

Green, Leonard; Freed, Debra E

1993-07-01

193

Black Hessians: American Blacks as German Soldiers.  

ERIC Educational Resources Information Center

|The German army in America during the Revolutionary War enlisted Blacks as musicians, laborers, and soldiers. Black soldiers contributed to the mercenaries' military activities, while the German units offered Blacks employment, clothing, food, and a type of escape from slavery. (Author/MJL)|

Hoffman, Elliott W.

1981-01-01

194

Two-nucleotide codon change in a hemoglobin polymorphism of the Celebes black ape (Macaca nigra).  

PubMed

A hemoglobin polymorphism involving variant beta-chains was demonstrated in the Celebes black ape, Macaca nigra. Fingerprinting and amino acid analysis of the tryptic peptides from the two chain types have shown that they differ by a single amino acid substitution, between lysine and aspartic acid, which requires a two-nucleotide change in the corresponding codon. Another substitution in the same codon is found as a species between the black ape and that of other macaques. PMID:816351

Murata, M; Thompson, P E

1976-02-01

195

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.

196

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

197

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

198

Sensory substitution in prosthetics.  

PubMed

Use of arm and hand prostheses may be essential for many amputees to facilitate activities of daily life and interaction with society. A major drawback that reduces the use of prostheses, however, is the lack of sensibility. Current strategies for sensory feedback in commercially available prostheses are based on force and slip sensors in the mechanical hand for independent grasp control in an opening and closing function. Developing principles for providing conscious sensibility is discussed, including new techniques where hearing is used as substitution for sensation based on sense substitution. PMID:11599215

Lundborg, G; Rosén, B

2001-08-01

199

Alcohol interaction with zirconia powders  

Microsoft Academic Search

The mechanism by which alcohol washing of ceramic powders produces soft agglomerates has been investigated by studying the interaction of ethanol with hydrous ZrOâ powders using Fourier transform infrared (FTIR) spectroscopy. Unambiguous evidence of ethoxide formation has been found, which apparently prevents bond formation between adjacent particles and thus the formation of hard agglomerates.

Mary Sue Kaliszewski; Arthur H. Heuer

1990-01-01

200

Powdered resin for condensate polishing  

Microsoft Academic Search

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

Richard Hetherington

1997-01-01

201

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

202

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

203

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

204

Organic vs. traditional potato powder  

Microsoft Academic Search

In this work the profile of primary metabolites in potato (Solanum tuberosum L., cultivar Agria) grown under organic vs traditional farming system was studied, and the influence of heat processing (for producing potato powder) on nutritionally important compounds such as essential amino acids, proteins and carbohydrates was evaluated. The potato powder was obtained by means of a drum dryer using

Petronia Carillo; Domenico Cacace; Stefania De Pascale; Mariateresa Rapacciuolo; Amodio Fuggi

205

Innovations in titanium powder processing  

NASA Astrophysics Data System (ADS)

One way of reducing the cost of titanium components is to use near-net shape powder-metallurgy techniques. This article describes a number of new approaches to producing components using the powder-metallurgy method for the aerospace, industrial, and consumer marketplaces.

Moxson, Vladimir; Senkov, O. N.; Froes, F. H.

2000-05-01

206

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

207

21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2009-04-01

208

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

209

Black Feminist Theory  

Microsoft Academic Search

Black feminist consciousness arises from an understanding of intersecting patterns of discrimination. If race and gender are studied as separate categories, one cannot explain how attitudes might change as a result of cross-pressures to subordinate the interests of black women so as to protect black men. In this essay, I start with a discussion of black feminist consciousness, providing an

Evelyn M. Simien

2004-01-01

210

Black Holes and Beyond  

NSDL National Science Digital Library

This website, from the University of Illinois, contains information about black holes. A brief history of black holes, a description of how black holes are formed, and the anatomy of a black hole are presented. Images and movies accompany the text and links to more information are provided throughout the site.

2007-06-01

211

Generating query substitutions  

Microsoft Academic Search

We introduce the notion of query substitution, that is, gen- erating a new query to replace a user's original search query. Our technique uses modications based on typical substitu- tions web searchers make to their queries. In this way the new query is strongly related to the original query, contain- ing terms closely related to all of the original terms.

Rosie Jones; Benjamin Rey; Omid Madani; Wiley Greiner

2006-01-01

212

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

213

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

214

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

Microsoft Academic Search

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

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

2008-01-01

215

A Computer-Assisted Method for Evaluating Ingredient Substitution in Ice Cream Formulations1  

Microsoft Academic Search

Development of a computer-based sys- tem to evaluate the effect of ingredient substitution in ice cream mix on product quality and freezing requirements is de- scribed. This computer program evaluates the effect of whey powder substitution for milk solids-not-fat and three sugar systems on freezing point, viscosity, and freezing time of ice cream mix. To help to evaluate potential product

A. S. Bakshi; D. E. Smith

1985-01-01

216

30 CFR 56.6133 - Powder chests.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Powder chests. 56.6133 Section 56...ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH...Explosives Storage § 56.6133 Powder chests. (a) Powder chests...

2010-07-01

217

30 CFR 56.6133 - Powder chests.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Powder chests. 56.6133 Section 56...ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH...Explosives Storage § 56.6133 Powder chests. (a) Powder chests...

2009-07-01

218

Properties of Prealloyed Steel Powder Metallurgy Products.  

National Technical Information Service (NTIS)

The applicability of conventional powder metallurgy fabrication procedures to prealloyed steel powders was investigated. Fifteen lots of steel powder, representing six different major alloy types (4130, 1040, 8620, 4650, 8650, and 9450), have been formed ...

K. R. Sump R. E. Westerman

1971-01-01

219

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

220

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

221

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

222

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

223

Compaction of Amorphous Ferromagnetic Metal Powders.  

National Technical Information Service (NTIS)

The attractive magnetic properties of certain amorphous metal powders might be exploited in the electrical industry if the powders can be consolidated into relatively dense compacts. The production of integral bodies of an amorphous powder was attempted u...

R. D. Caligiuri

1982-01-01

224

21 CFR 73.1645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

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

2013-04-01

225

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

...2013-04-01 2013-04-01 false Aluminum powder. 73.2645 Section 73...CERTIFICATION Cosmetics § 73.2645 Aluminum powder. (a) Identity and specifications. The color additive aluminum powder shall conform in...

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...CERTIFICATION Cosmetics § 73.2647 Copper powder. (a) Identity and specifications. The color additive copper powder shall conform in identity...

2013-04-01

227

Characterization of mutagenic activity in instant hot beverage powders.  

PubMed

Extracts of several grain-based coffee-substitute blends and instant coffees were mutagenic in the Ames/Salmonella test using TA98, YG1024, and YG1029 with metabolic activation. The beverage powders induced 150 to 500 TA98 and 1,150 to 4,050 YG1024 revertant colonies/g, respectively. Increased sensitivity was achieved using strain YG1024. No mutagenic activity was found in instant hot cocoa products. The mutagenic activity in the beverage powders was shown to be stable to heat and the products varied in resistance to acid nitrite treatment. Differential bacterial strain specificity, and a requirement for metabolic activation suggest that aromatic amines are present. Characterization of the mutagenic activity, using HPLC and the Ames test of the collected fractions, showed the coffee-substitute blends and instant coffees contain several mutagenic compounds. Known heterocyclic amines are not responsible for the major part of the mutagenic activity. The main mutagenic activity in grain-based coffee-substitute blends and instant coffees is due to several unidentified compounds, which are most likely aromatic amines. PMID:7698108

Johansson, M A; Knize, M G; Jägerstad, M; Felton, J S

1995-01-01

228

Silica powders for powder evacuated thermal insulating panel and method  

DOEpatents

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

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

1996-01-01

229

Silica powders for powder evacuated thermal insulating panel and method  

DOEpatents

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

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

1995-01-01

230

Silica powders for powder evacuated thermal insulating panel and method  

DOEpatents

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

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

1994-01-01

231

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

232

EFFICIENT ATTACKS ON HOMOPHONIC SUBSTITUTION CIPHERS  

Microsoft Academic Search

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

Amrapali Dhavare

2011-01-01

233

Substitution reactions of carbon nanotube template  

NASA Astrophysics Data System (ADS)

Substitution reactions between carbon nanotube (CNT) template and SiO with the formation of carbon rich silicon oxide nanowires (SiO-C-NWs) have been investigated using transmission electron microscopy and x-ray energy dispersive spectroscopy. The reaction was carried out by thermal annealing at 1200 °C for 1 h of a mixture of silicon monoxide (SiO) and iron (II) phthalocyanine, FeC32N8H16 (FePc) powders. Multiwalled CNTs were produced first via pyrolysis of FePc at a lower temperature (1000 °C). SiO vapors reacted with the CNTs at higher temperatures to produce amorphous SiO-C-NWs with a uniform diameter and a length in tens of micrometers. The special bamboolike structure of the CNTs allows the reaction to start from the external surface of the tubes and transform each CNT into a solid nanowire section by section.

Li, Chi Pui; Chen, Ying; Gerald, John Fitz

2006-05-01

234

Shock compaction of molybdenum powder  

SciTech Connect

Shock recovery experiments carried out in the 9 to 12 GPa range on 1.4 distension Mo appear adequate to compact to full density (< 45 ..mu..m) powders. However, the stress levels 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 ..mu..m particles. The present model predicts that for powders 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 ..mu..m range.

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

1983-09-01

235

Skin substitutes: An Indian perspective  

PubMed Central

There have been numerous alternatives developed to replace skin. These can either be permanent substitutes or temporary substitutes, which need to be replaced later by autologous grafts. These have been tried in recent times as an attempt to reduce the need or in the case of permanent substitutes ,altogether replace autologous skin grafts. However till date no ideal skin substitute has been developed. Various factors have to be considered while choosing one of these substitutes. In a developing country like India awareness and availability of these skin substitutes is not adequate considering the volume of cases that require this modality of treatment. Also there are skin substitutes developed in our country that need to be highlighted. This article is an attempt to review the vast array of skin substitutes that have been developed and consider their utility and feasibility for developing countries.

Singh, A. K.; Shenoy, Y. R.

2012-01-01

236

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

PubMed Central

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

2012-01-01

237

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

SciTech Connect

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

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

2012-05-15

238

Comparison of hydration, tyrosinase resistance, and antioxidant activation in three kinds of pearl powders.  

PubMed

In recent years, people have bred freshwater pearls as a substitute for natural pearls that occur in seawater, and they have also developed water-soluble pearl powder (P-w) and ultra-micro (P-mu) and ultra-nano pearl powder (P-n) products. However, neither the scientific value of pearl powder, nor the differences in efficiencies of different pearl powder products is still unknown. In this study, the effectiveness of three kinds of pearl powder products in various applications was compared. Tests for transepidermal water loss (TEWL) and evaluations of the skin surface hydration of test subjects showed that pearl powder has a satisfactory moisturizing effect on skin and that P-mu has a distinctly stronger moisturizing effect than P-w. The three pearl powder products can also significantly reduce the activation of tyrosinase and free radicals. In tests for reducing power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) for scavenging free radicals, P-n and P-mu showed better performance than P-w. These results provide a reliable scientific basis for the use of pearl powder in beauty treatment, resistance to aging, and clinical medical treatment. PMID:20447365

Shao, Dong-Zi; Wang, Cheng-Kun; Hwang, Hann-Jang; Hung, Ching-Hsia; Chen, Yu-Wen

239

Growth and phosphorus loading by partially replacing fishmeal with tuna muscle by-product powder in the diet of juvenile Japanese flounder, Paralichthys olivaceus  

Microsoft Academic Search

Tuna muscle by-product powder (TMP), obtained from residues of tuna muscle, was replaced with fishmeal to evaluate its quality, substitution level and phosphorus loading for juvenile Japanese flounder. TMP was substituted for fishmeal on a crude protein basis with levels of 25%, 50%, 75% and 100%, respectively. The feeding trial continued for 40days. Weight gain, specific growth rate and feed

Orhan Uyan; Shunsuke Koshio; Shin-ichi Teshima; Manabu Ishikawa; Moe Thu; Md. Shah Alam

2006-01-01

240

Substitutional carbon in germanium  

Microsoft Academic Search

Carbon impurities implanted into single-crystalline germanium are studied with infrared absorption spectroscopy and ion channeling. After implantation of 12C+ at room temperature and subsequent annealing at 350 °C, a sharp infrared absorption line is observed at 531 cm-1. When 12C+ is substituted by 13C+, the line shifts down in frequency to 512 cm-1 and co-implantation of 12C+ and 13C+ does

L. Hoffmann; J. C. Bach; B. Bech Nielsen; P. Leary; R. Jones; S. Öautberg

1997-01-01

241

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

242

Crystallization of comminuted boron powders  

Microsoft Academic Search

An x-ray diffraction investigation has established that, irrespective of their degree of amorphization, comminuted boron powders crystallize after melting in the rhombohedralß structure, i.e., revert to their original crystalline state.

K. P. Tsomaya; D. L. Gabuniya; É. A. Knyshev; V. A. Kobyakov

1975-01-01

243

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

244

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

2011-01-20

245

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

Microsoft Academic Search

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

Kalyoncu

1986-01-01

246

Explosive containment with spherically tamped powders  

Microsoft Academic Search

An effective technique for maximizing the explosive charge that a given container can safely handle is to fill the space between the charge and the container walls with a porous medium or a powder. Using the wrong powder, however, can be worse than using no powder at all. Moreover, a powder-filled container that performs very well with a small charge

L. A. Glenn

1986-01-01

247

Ceramic oxide powders and the formation thereof  

DOEpatents

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

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

1993-01-01

248

Surface characterization of emulsified lithium powder electrode  

Microsoft Academic Search

The surface modification of Li powder was attempted in order to enhance the electrochemical properties of the electrodes used in rechargeable batteries. To create a “native” LiF film on Li powder, Li powder was manufactured using a droplet emulsion technique (DET) process by introducing fluoride as a surfactant. The surface modification of the Li powder was confirmed by means of

Seung-Taek Hong; Jin-Suk Kim; Suk-Jun Lim; Woo Young Yoon

2004-01-01

249

Investigation of the recyclability of powder coatings  

Microsoft Academic Search

100% recyclability is one of the major advantages of powder coating. However, it can never be achieved in reality. Coating powders, especially finer powders with particle size below 30?m, were found to have much worse flow performances after recycling from electrostatic spraying so as to decrease the recyclability. Therefore, this study was designed to investigate recycled coating powders to determine

Jing Fu; Matthew Krantz; Hui Zhang; Jesse Zhu; Harry Kuo; Yar Ming Wang; Karen Lis

2011-01-01

250

Black widow spider (image)  

MedlinePLUS

This is a black widow spider. Note the red "hour glass" on the abdomen. The bite of the black widow can produce severe symptoms but is seldom fatal, except in young children and older adults. (Image courtesy ...

251

Cambridge Cosmology: Black Holes  

NSDL National Science Digital Library

This Cambridge Cosmology site introduces the concept of black holes, explaining their properties and presenting observational evidence for their existence. Also covered are black hole formation, and determination of weight, size, and distance.

Stewart, John; Hamade, Rufus

252

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

National Technical Information Service (NTIS)

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 revert...

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

1994-01-01

253

Topological dilaton black holes  

Microsoft Academic Search

In four-dimensional spacetime, when the two-sphere of black hole event horizons is replaced by a two-dimensional hypersurface with zero or negative constant curvature, the black hole is referred to as a topological black hole. In this paper we present some exact topological black hole solutions in the Einstein-Maxwell dilaton theory with a Liouville-type dilaton potential.

Rong-Gen Cai; Jeong-Young Ji; Kwang-Sup Soh

1998-01-01

254

Black Hole Berry Phase  

SciTech Connect

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

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

2009-09-25

255

Novel single-layer gas diffusion layer based on PTFE\\/carbon black composite for proton exchange membrane fuel cell  

Microsoft Academic Search

A series of poly(tetrafluoroethylene)\\/carbon black composite-based single-layer gas diffusion layers (PTFE\\/CB-GDLs) for proton exchange membrane fuel cell (PEMFC) was successfully prepared from carbon black and un-sintered PTFE, which included powder resin and colloidal dispersion, by a simple inexpensive method. The scanning electron micrographs of PTFE\\/CB-GDLs indicated that the PTFE resins were homogeneously dispersed in the carbon black matrix and showed

Y. W. Chen-Yang; T. F. Hung; J. Huang; F. L. Yang

2007-01-01

256

Alcoholism and Blacks.  

ERIC Educational Resources Information Center

|Notes that in America, knowledge base concerning alcoholism is concentrated on drinking patterns of Whites, and that Black Americans often differ in their drinking behavior, resulting in a need to clarify issues regarding alcoholism and Blacks. Provides theoretical information useful in better discerning drinking behavior of Blacks. (Author/NB)|

Mosley, Bertha; And Others

1988-01-01

257

The Black Woman.  

ERIC Educational Resources Information Center

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

Browne, Juanita M.

258

To Liberate Black Actors.  

ERIC Educational Resources Information Center

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

Riley, Clayton

1983-01-01

259

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

260

Substituted isoquinolinones and quinazolinones  

US Patent & Trademark Office Database

The invention relates to substituted nitrogen containing bicyclic heterocycles of the formula (I) ##STR00001## wherein Z is CH.sub.2 or N--R.sup.4 and X, R.sup.1, R.sup.2, R.sup.4, R.sup.6, R.sup.7 and n are as defined in the description. Such compounds are suitable for the treatment of a disorder or disease which is mediated by the activity of MDM2 and/or MDM4, or variants thereof.

Berghausen; Joerg (Basel, CH); Buschmann; Nicole (Basel, CH); Furet; Pascal (Basel, CH); Gessier; Francois (Basel, CH); Lisztwan; Joanna Hergovich (Basel, CH); Holzer; Philipp (Basel, CH); Jacoby; Edgar (Basel, CH); Kallen; Joerg (Basel, CH); Masuya; Keiichi (Basel, CH); Soldermann; Carole Pissot (Basel, CH); Ren; Haixia (Shanghai, CN); Stutz; Stefan (Basel, CH)

2013-05-14

261

Bioengineered skin substitutes.  

PubMed

Bioengineered skin has great potential for use in regenerative medicine for treatment of severe wounds such as burns or chronic ulcers. Genetically modified skin substitutes have also been used as cell-based devices or "live bioreactors" to deliver therapeutics locally or systemically. Finally, these tissue constructs are used as realistic models of human skin for toxicological testing, to speed drug development and replace traditional animal-based tests in a variety of industries. Here we describe a method of generating bioengineered skin based on a natural scaffold, namely, decellularized human dermis and epidermal stem cells. PMID:23494436

Lei, Pedro; You, Hui; Andreadis, Stelios T

2013-01-01

262

Mechanochemical synthesis of ultrafine Ti(C,N)–Al 2O 3 composite powders and phase transformation  

Microsoft Academic Search

Titanium carbonitride–alumina (Ti(C,N)–Al2O3) composite powders with ultrafine-sized particles below 0.5?m were successfully synthesized by mechanochemical method. That is to say, mixed powders of anatase\\/aluminum\\/carbon black were mechanically milled for 40h under N2\\/Ar atmosphere and were subsequently vacuum heat treated for 1h at 800–1100°C. From X-ray diffraction (XRD) and thermogravimetry–differential scanning calorimetry (TGA–DSC) results of milled powders, Ti(C,N)–Al2O3 phases were formed

D. P. Xiang; Y. Liu; M. J. Tu; Y. Y. Li; S. Xia; B. Q. Chen

2009-01-01

263

Neutron powder diffraction and first-principles computational studies of CuLi{sub x}Mg{sub 2-x} (x{approx_equal}0.08), CuMg{sub 2}, and Cu{sub 2}Mg  

SciTech Connect

A small addition of Li changes the orthorhombic structure of CuMg{sub 2} to hexagonal CuLi{sub x}Mg{sub 2-x} (x=0.08). Determining the Li content of the ternary phase and Li atomic positions was our main objective for this work. For this reason we performed neutron diffraction at several different temperatures below and above room temperature. The results obtained on two neutron powder diffractometers were compared with X-ray diffraction (XRD) data, and with first-principles calculations. The first-principles calculations are in good agreement with Rietveld-refined data from neutron diffraction, but do not show a marked preference for one of several possible Li sites. The pair distribution function (PDF) fitting is consistent with Li substituting only Mg1 (1/2, 0, z). Interstitial spaces in the structure of CuMg{sub 2} and of CuLi{sub x}Mg{sub 2-x} were also considered, but are unlikely to be occupied by Li. Neutron diffraction data for binary CuMg{sub 2} and Cu{sub 2}Mg were also obtained. - Graphical abstract: CuLi{sub x}Mg{sub 2-x} with x=0.08 crystallizes in a P6{sub 2}22 hexagonal structure in which Li (red) will substitute Mg1 (1/2, 0, z) sites (Mg-grey). Cu atoms are represented by black spheres and empty spaces by transparent ones.

Braga, M.H., E-mail: mbraga@fe.up.p [Manuel Lujan, Jr. Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); CEMUC and Physics Engineering Department, Engineering Faculty of the University of Porto, R. Dr. Roberto Frias, s/n, 4200-465 Porto (Portugal); Ferreira, J.J.A. [LNEG Laboratory, R. da Amieira-P.O. Box 1089, 4466-956 S. Mamede de Infesta (Portugal); Siewenie, J.; Proffen, Th.; Vogel, S.C.; Daemen, L.L. [Manuel Lujan, Jr. Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2010-01-15

264

Newly developed Sr-substituted alpha-TCP bone cements.  

PubMed

New bone cements made of Sr-substituted brushite-forming alpha-tricalcium phosphate (alpha-TCP) were prepared and characterized in the present work. The quantitative phase analysis and structural refinement of the starting powders and of hardened cements were performed by X-ray powder diffraction and the Rietveld refinement technique. Isothermal calorimetry along with setting time analysis allowed a precise tracing of the setting process of the pastes. The pastes showed exothermic reactions within the first 10-15 min after mixing and further release of heat after about 1h. An apatitic phase formed upon immersion of the hardened cements in simulated body fluid for 15 and 30 days due to the conversion of brushite into apatite confirming their in vitro mineralization capability. The compressive strength of the wet cement specimens decreased with increasing curing time, being higher in the case of Sr-substituted CPC. The results suggest that the newly developed Sr-substituted brushite-forming alpha-TCP cements show promise for uses in orthopaedic and trauma surgery such as in filling bone defects. PMID:19733700

Pina, S; Torres, P M; Goetz-Neunhoeffer, F; Neubauer, J; Ferreira, J M F

2009-09-04

265

Black hole levitron  

SciTech Connect

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

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

2010-04-15

266

Structural analysis of 100% relative intense peak of Ba1-xCaxTiO3 ceramics by X-ray powder diffraction method  

NASA Astrophysics Data System (ADS)

Highly crystalline powders of modified BaTiO3 have been prepared by high-energy ball milling. The powder mixture was ball milled for 2 h at 300 rpm. Microstructure characterization of all the ball-milled powder mixtures was done by analyzing the X-ray powder diffraction data. The diffracted intensity depends on several factors which are geometric in nature, and gives a lot of information about the samples. In this study the variations of microstructure imperfection are reported with variation in Ca substitution.

Panigrahi, M. R.; Panigrahi, S.

2010-04-01

267

Mask materials for powder blasting  

NASA Astrophysics Data System (ADS)

Powder blasting, or abrasive jet machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials such as glass, silicon and ceramics. The particle jet (which expands to about 1 cm in diameter) can be optimized for etching, while the mask defines the small and complex structures. The quality of the mask influences the performance of powder blasting. In this study we tested and compared several mask types and added a new one: electroplated copper. The latter combines a highly resistant mask material for powder blasting with the high-resolution capabilities of lithography, which makes it possible to obtain an accurate pattern transfer and small feature sizes (<50 µm).

Wensink, Henk; Jansen, Henri V.; Berenschot, J. W.; Elwenspoek, Miko C.

2000-06-01

268

Substituted hydroxyapatites for bone repair.  

PubMed

Calcium phosphates such as hydroxyapatite have a wide range of applications both in bone grafts and for the coating of metallic implants, largely as a result of their chemical similarity to the mineral component of bone. However, to more accurately mirror the chemistry, various substitutions, both cationic (substituting for the calcium) and anionic (substituting for the phosphate or hydroxyl groups) have been produced. Significant research has been carried out in the field of substituted apatites and this paper aims to summarise some of the key effect of substitutions including magnesium, zinc, strontium, silicon and carbonate on physical and biological characteristics. Even small substitutions have been shown to have very significant effects on thermal stability, solubility, osteoclastic and osteoblastic response in vitro and degradation and bone regeneration in vivo. PMID:22389101

Shepherd, Jennifer H; Shepherd, David V; Best, Serena M

2012-03-03

269

Confidence in generic drug substitution.  

PubMed

Patients should have confidence that the generic drugs they are prescribed in the United States can be effectively substituted for the brand product or another generic product. Through new bioequivalence study designs for narrow therapeutic index (NTI) drugs and postapproval studies of generic substitution, the US Food and Drug Administration's (FDA's) ongoing generic drug regulatory science activities are designed to ensure successful generic substitution for all drug products. PMID:24048239

Lionberger, R; Jiang, W; Huang, S-M; Geba, G

2013-10-01

270

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

SciTech Connect

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

Paniconi, Giordano; Stoeva, Zlatka [School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Smith, Ronald I. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Dippo, Patricia C. [Measurements and Characterization Division, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401 (United States); Gallagher, Bryan L. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Gregory, Duncan H. [Department of Chemistry, WestCHEM, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom)], E-mail: D.Gregory@chem.gla.ac.uk

2008-01-15

271

Silent nucleotide substitutions during evolution  

NASA Astrophysics Data System (ADS)

Silent nucleotide substitutions in evolution are found by comparing homologous sequences of DNA from different organisms. Silent changes are common in the third bases of codons, so that no change takes place in the specified amino acid. Silent changes average about half of the total nucleotide substitutions during evolution of protein-coding regions of genes. Nucleotide substitutions also take place during evolution in non-coding regions of DNA, such as in intervening sequences and in sequences that precede and follow codon regions in genes. Deletions and additions from events of recombination, in addition to nucleotide substitutions, are common in these non-coding regions.

Jukes, Thomas H.

1980-11-01

272

Sulfur-substituted tetrahedranes.  

PubMed

The stable sulfur-substituted tetrahedrane derivatives 2-4 were synthesized by the reaction of tris(trimethylsilyl)tetrahedranyllithium 1 with diphenyl disulfide, bis(4-nitrophenyl) disulfide, and bis(2,4-dinitrophenyl) disulfide, respectively, and characterized by both NMR spectroscopy and X-ray crystallography. Phenylsulfonyltetrahedrane 5 was prepared by the reaction of 2 and m-chloroperbenzoic acid. The UV-vis absorption spectra of 2-4 suggested an interaction of the ? orbital of the tetrahedrane core and the lone-pair electrons on the sulfur atom, whereas no interaction for 5 was found. Thermal reactions of 2 and 5 are also reported; 2 underwent fragmentation into two acetylene molecules, whereas 5 gave the corresponding cyclobutadiene. PMID:21728313

Ochiai, Tatsumi; Nakamoto, Masaaki; Inagaki, Yusuke; Sekiguchi, Akira

2011-07-07

273

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

274

Interaction between reinforce carbon black and polymeric matrix for industrial applications  

NASA Astrophysics Data System (ADS)

In this work the interaction between the carbon black reinforcement agent and a polymeric rubber matrix is investigated. Chemical activity of carbon black powder samples was enhanced using ? radiation in the dose range 168-1000 kGy and the radiation induced free radical concentration was investigated by EPR measurements. Activated powder samples were mixed with rubber and the bound rubber values of obtained compounds was measured by TG analysis. A comparison between EPR and bound rubber data shows that the greatest filler-polymer chemical interaction corresponds to the highest radiation induced free radical concentration.

Baccaro, S.; Cataldo, F.; Cecilia, A.; Cemmi, A.; Padella, F.; Santini, A.

2003-08-01

275

High resolution powder blast micromachining  

Microsoft Academic Search

Powder blasting, or Abrasive Jet Machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials like glass, silicon and ceramics. By introducing electroplated copper as a new mask material, the feature size of this process was decreased. It

Henk Wensink; J. W. Berenschot; Henri V. Jansen; Miko C. Elwenspoek

2000-01-01

276

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

277

Metallography of powder metallurgy materials  

SciTech Connect

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

Lawley, Alan; Murphy, Thomas F

2003-12-15

278

Pinwheel patterns and powder diffraction  

Microsoft Academic Search

Pinwheel patterns and their higher dimensional generalisations display continuous circular or spherical symmetries in spite of being perfectly ordered. The same symmetries show up in the corresponding diffraction images. Interestingly, they also arise from amorphous systems, and also from regular crystals when investigated by powder diffraction. We present first steps and results towards a general frame to investigate such systems,

Michael Baake; D. Frettlöh; Uwe Grimm

2007-01-01

279

Flow Properties of Powder III  

Microsoft Academic Search

When glass granules coated with various amounts of oleic acid are packed into the annular space between two rotating coaxial cylinders, they exhibit the so-called plug flow around the inner cylinder. Theoretically, we have established a method of measuring the internal friction coefficient and cohesive force of loosely packed powder by means of a rotating coaxial cylinder rheometer. The internal

Shin'ichi Taneya

1969-01-01

280

Powdered epoxy resin test methods  

Microsoft Academic Search

The author describes several test methods which may be used to evaluate powdered epoxy resins for their potential use as integral insulation on fractional horsepower motor iron. These are the edge coverage test method, the hot plate gel time test method, the glass pellet flow test method, and the steel panel impact test method. These test methods may be of

N. Hanssen

1991-01-01

281

Shock Compaction of Molybdenum Powder.  

National Technical Information Service (NTIS)

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 a...

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

1983-01-01

282

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...

283

Solar drying of custard powder  

Microsoft Academic Search

A large scale forced convection solar drying system has been designed and fabricated, comprising an array of forty solar collectors and three drying cabinets with a blower. Such a system yields 300 kg of dry product of custard powder in a normal sunshine day. It is shown that such a system is feasible and has an ability to save large

R. S. Pawar; M. G. Takwale; V. G. Bhide

1995-01-01

284

Powder metallurgy of titanium alloys  

Microsoft Academic Search

The powder metallurgy of titanium alloys is studied with attention given to blended elemental and prealloyed (PA) approaches. The PA method leads to mechanical behavior in all respects at least at ingot metallurgy levels. The use of the PA method in the aerospace industry is discussed. 230 refs.

F. H. Froes; D. Eylon

1990-01-01

285

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

NASA Astrophysics Data System (ADS)

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

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

1996-10-01

286

Resistance-induced antibiotic substitution  

Microsoft Academic Search

In many cases, physicians prescribe antibiotics without knowing whether an individual patient is infected with a susceptible or resistant pathogen. As the proportion of resistant organisms in a community increases, physicians substitute away from older-inexpensive drugs to newer, more expensive agents as first line therapy. This paper explores the implications of resistance-induced antibiotic substitution for epidemiological models to predict future

David H. Howard

2004-01-01

287

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

288

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.

289

Low Porosity Powder Metallurgy Produced Components.  

National Technical Information Service (NTIS)

Components produced by powder metallurgy techniques are described herein. Embodiments of these components have little or no porosity therein after processing. Embodiments of these components are created by creating a preform from a powder; creating a comp...

G. Das

2004-01-01

290

Powder Metallurgy Production of Structural Shapes.  

National Technical Information Service (NTIS)

The program involves an integrated and concurrent study of closely-related topics which represent major critical steps and/or problem areas in a wide variety of powder metallurgy processes. Areas of study include atomization, powder characteristics (and t...

A. Lawley H. L. Gaigher R. H. Haase R. W. Heckel M. J. Koczak

1971-01-01

291

Powdered Metal Sintering of Jet Vanes.  

National Technical Information Service (NTIS)

This report presents the successful efforts to use powdered metallurgy techniques in manufacturing jet vanes from sintered and copper infiltrated tungsten. Isostatic pressing of the powdered tungsten to net shape imparts sufficient hardening to allow hand...

M. J. Ripley-Lotee S. M. O'Neil

1982-01-01

292

Homogeneous Precipitation of Nickel Hydroxide Powders.  

National Technical Information Service (NTIS)

Precipitation and characterization of nickel hydroxide powders were investigated. A comprehensive precipitation model incorporating the metal ion hydrolysis, complexation and precipitation reactions was developed for the production of the powders with ure...

B. Mavis

2003-01-01

293

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2013 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2646 Bronze powder. (a) Identity...Bronze powder may be safely used in coloring cosmetics generally, including cosmetics intended for use in the area of the eye,...

2013-04-01

294

Properties of Prealloyed Steel Powder Metallurgy Products.  

National Technical Information Service (NTIS)

A program to evaluate the properties of prealloyed steel powders, consolidated by various fabrication techniques, was conducted. Sixteen lots of low-alloy prealloyed steel powder, representing seven different major alloys (4130, 1040, 8620, 4640, 4650, 86...

R. E. Westerman K. R. Sump

1972-01-01

295

Characterization of Powder Coated Thermoplastic Composite.  

National Technical Information Service (NTIS)

Thermoplastic powder resin preforms are a relatively new form of composite preform material. Powder preforms offer improved handelability as well as the possibility to produce composites from resins that are difficult to prepreg. The purpose of this proje...

R. Cochran

1991-01-01

296

Powder Metallurgy Production of Structural Shapes.  

National Technical Information Service (NTIS)

This program has involved an integrated and concurrent study of closely-related topics representing major critical steps and/or problem areas in powder metallurgy processing. The areas of major concern have been: quench atomization; powder compaction; pow...

A. Lawley M. J. Koczak R. M. Koerner H. A. Kuhn H. C. Rogers

1973-01-01

297

Naked black holes  

SciTech Connect

It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces {ital outside} the horizon. These black holes are charged and near extremality, and exist in a wide class of theories including string theory. The implications for cosmic censorship and the black hole information puzzle are discussed. {copyright} {ital 1997} {ital The American Physical Society}

Horowitz, G.T.; Ross, S.F. [Department of Physics, University of California, Santa Barbara, California 93106 (United States)

1997-08-01

298

BlackBerry  

Microsoft Academic Search

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

Sarah Allen; Vidal Graupera; Lee Lundrigan

299

Black nightshade poisoning  

MedlinePLUS

Black nightshade plant, especially in the unripened fruit and leaves. ... pupils Gastrointestinal Diarrhea Stomach pain Vomiting Heart and blood ... Headache Loss of sensation Paralysis Whole body Sweating

300

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

301

Amorphous metal powder for coating substrates  

Microsoft Academic Search

The present invention is for a flat B containing amorphous powder based in Fe, Ni, Co or a combination thereof; a coating resulting from deposition of the powder; and a method for depositing the powder. The composition of the powder and the resulting coating consists essentially of the formulation: (Fe,Ni,Co) \\/sub bal\\/ Crâ⁻ââ(Mn,Mo,W)â⁻ââ (B,Si,C)â⁻ââ(Al,Ti)â⁻ââ where the subscripts are in atomic

J. Dickson; L. F. Nienart; D. W. Roth

1985-01-01

302

Regular Cu-based amorphous alloy powder  

Microsoft Academic Search

The plate-like powder of Cu60Zr30Ti10 amorphous alloy was prepared by ball milling. The amorphization and deformation mechanisms and thermodynamic properties were also investigated. The powders are milled into plate-like powders and their thicknesses decrease with increasing of milling time. After milling for 184h, the size of the powders decreases down to 250nm and an amorphous structure appears. The average deformation

An-hui Cai; Xiang Xiong; Yong Liu; Yong Zhou; Wei-ke An; Yun Luo

2010-01-01

303

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

304

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

305

Process for manufacturing uranium dioxide powder  

Microsoft Academic Search

A process is described for manufacturing uranium dioxide powder which comprises forming fine uranium dioxide powder having a high sinterability and coarse uranium dioxide powder having a low sinterability continuously in one process by changing periodically the precipitation condition of the ammonium diuranate under the same condition of calcining and reducing of the ammonium diuranate. The thus obtained mixture of

Sh. I. Hasegawa; M. Sekine; E. Takano

1985-01-01

306

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

307

Sorption of nicotine to cellulose powders  

Microsoft Academic Search

The purpose of this study was to investigate the influence of the crystallinity, surface area, and pore volume of cellulose powders on the loading, release, and stability of nicotine. Four different types of cellulose powders with varying crystallinity index, surface area, and pore volume were produced and characterized. The powders were loaded with nicotine by rotary evaporation from an ethanol

Albert Mihranyan; Sven-Börje Andersson; Ragnar Ek

2004-01-01

308

Magnetic Orientation of BI-2212 Powder  

NASA Astrophysics Data System (ADS)

The Accelerator Lab at Texas A&M is developing a method of texturing Bi-2212 powder for an oriented powder multifilament round wire. Results of preliminary experiments relating to the orientation of Bi-2212 powders by magnetic fields are presented.

Damborsky, K.; McIntyre, P.; Pogue, N.

2010-04-01

309

Powder metallurgy repair of turbine components  

Microsoft Academic Search

An advanced powder metallurgy repair process called Liburdi Powder Metallurgy (LPM) has been developed for the repair, overlay or joining of nickel and cobalt-based high-temperature alloys. This process involves mechanical cleaning, followed by the application and consolidation of a filler metal powder, which has substantially the same composition as the base metal, and producer joints with mechanical properties similar to

K. A. Ellison; P. Lowden; J. Liburdi

1994-01-01

310

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

311

Spherical particles for automotive powder coatings  

Microsoft Academic Search

Clear powder coatings that consist of spherical particles with a narrow particle size distribution were produced via a suspension method that involves the agglomeration and unification of smaller particles. These powder coatings have the advantages of excellent powder flowability and high transfer efficiency. This behavior is attributable to the spherical particle shape and absence of finer particles. This production method

Haruhiko Satoh; Yutaka Harada; Shannon Libke

1997-01-01

312

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...FROM CERTIFICATION Drugs § 73.1647 Copper powder. (a) Identity. (1) The color additive copper powder is a very fine free-flowing...

2013-04-01

313

Implementation of the Powder Dispensing of Digitization  

Microsoft Academic Search

Dose uniformity is one of the important factors in evaluation of microfeeding of fine powders. This paper describes a method for metering and dispensing the fine metal powders. The principle of the powder dispensing of digitalization is distinct from ultrasonic microfeeding, and it not only achieved continuous feeding, but also guaranteed dose uniformity. To avoid the relative movement and with

Xin Geng; Li-ya Hou; Wei-yi Zhang

2010-01-01

314

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

315

40 CFR Appendix A to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes  

Code of Federal Regulations, 2012 CFR

...G, App. A Appendix A to Subpart G of Part 82âSubstitutes Subject to Use Restrictions and Unacceptable Substitutes Refrigerants Unacceptable Substitutes End-use Substitute Decision Comments CFC-11 centrifugal chillers (retrofit)...

2012-07-01

316

Substitution and pooling in crowding.  

PubMed

Unless we fixate directly on it, it is hard to see an object among other objects. This breakdown in object recognition, called crowding, severely limits peripheral vision. The effect is more severe when objects are more similar. When observers mistake the identity of a target among flanker objects, they often report a flanker. Many have taken these flanker reports as evidence of internal substitution of the target by a flanker. Here, we ask observers to identify a target letter presented in between one similar and one dissimilar flanker letter. Simple substitution takes in only one letter, which is often the target but, by unwitting mistake, is sometimes a flanker. The opposite of substitution is pooling, which takes in more than one letter. Having taken only one letter, the substitution process knows only its identity, not its similarity to the target. Thus, it must report similar and dissimilar flankers equally often. Contrary to this prediction, the similar flanker is reported much more often than the dissimilar flanker, showing that rampant flanker substitution cannot account for most flanker reports. Mixture modeling shows that simple substitution can account for, at most, about half the trials. Pooling and nonpooling (simple substitution) together include all possible models of crowding. When observers are asked to identify a crowded object, at least half of their reports are pooled, based on a combination of information from target and flankers, rather than being based on a single letter. PMID:22160819

Freeman, Jeremy; Chakravarthi, Ramakrishna; Pelli, Denis G

2012-02-01

317

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

318

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

319

Wetter for fine dry powder  

DOEpatents

A system for wetting fine dry powders such as bentonite clay with water or other liquids is described. The system includes a wetting tank for receiving water and a continuous flow of fine powder feed. The wetting tank has a generally square horizontal cross section with a bottom end closure in the shape of an inverted pyramid. Positioned centrally within the wetting tank is a flow control cylinder which is supported from the walls of the wetting tank by means of radially extending inclined baffles. A variable speed motor drives a first larger propeller positioned immediately below the flow control cylinder in a direction which forces liquid filling the tank to flow downward through the flow control cylinder and a second smaller propeller positioned below the larger propeller having a reverse pitch to oppose the flow of liquid being driven downward by the larger propeller.

Hall, James E. (131 Arkansas Ave., Oak Ridge, TN 37830); Williams, Everett H. (198 Hillside Road, Oak Ridge, TN 37830)

1977-01-01

320

Peritonitis from Starch Glove Powder  

PubMed Central

Contamination of surgical wounds by starch glove powders has produced peritoneal inflammation and adhesions in many patients. Some have required surgical operation because of possible infection, others because of obstruction of the intestine. Resolving granulomas and fibrosis have been observed as incidental asymptomatic lesions in some patients during reoperation for other conditions. Starch granules are probably capable of producing inflammation in any patient, and the degree is believed to be related to the amount of starch present. Care in removing glove powder from gloves before they are worn in an operation will diminish or eliminate the problem. Removal can be accomplished by rubbing the gloves with a moist sterile towel or laparotomy tape. ImagesFigure 1.Figure 2.

Dutra, Frank R.; Jensen, C. David

1972-01-01

321

Pressure sintering of powder materials  

Microsoft Academic Search

Rheological models for pressure sintering of powder materials are described. The rheological models of deformable bodies and\\u000a the associated dynamic deformation theory for porous bodies based on the energy conservation law enable a quantitative description\\u000a of their densification under impulse and static hot pressing as well as hot forging using crank presses. The simulation of\\u000a compaction of porous metals shows

M. S. Kovalchenko

2011-01-01

322

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

323

Shock compaction of molybdenum powder  

Microsoft Academic Search

Shock recovery experiments carried out in the 9 to 12 GPa range on 1.4 distension Mo appear adequate to compact to full density (< 45 ..mu..m) powders. However, the stress levels 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 ..mu..m particles. The

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

1983-01-01

324

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

325

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

326

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

327

40 CFR 721.5867 - Substituted phenol.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 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,...

2010-07-01

328

40 CFR 721.4420 - Substituted hydroxylamine.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Substituted hydroxylamine. 721.4420 Section 721.4420...Substances § 721.4420 Substituted hydroxylamine. (a) Chemical substance and significant...identified generically as substituted hydroxylamine (PMN P-84-492) is subject...

2009-07-01

329

40 CFR 721.4420 - Substituted hydroxylamine.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted hydroxylamine. 721.4420 Section 721.4420...Substances § 721.4420 Substituted hydroxylamine. (a) Chemical substance and significant...identified generically as substituted hydroxylamine (PMN P-84-492) is subject...

2010-07-01

330

40 CFR 721.4280 - Substituted hydrazine.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Substituted hydrazine. 721.4280 Section 721.4280...Substances § 721.4280 Substituted hydrazine. (a) Chemical substance and significant...identified generically as substituted hydrazine (PMN P-90-594) is subject...

2009-07-01

331

40 CFR 721.4280 - Substituted hydrazine.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

332

40 CFR 721.4280 - Substituted hydrazine.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

333

Amorphous rare earth magnet powders  

SciTech Connect

Gas atomization (GA) processing does not generally have a high enough cooling rate to produce the initial amorphous microstructure needed to obtain optimal magnetic properties in RE{sub 2}Fe{sub 14}B alloys. Phase separation and an underquenched microstructure result from detrimental {alpha}-Fe precipitation, and the resulting magnetic domain structure is very coarse. Additionally, there is a dramatic dependence of the magnetic properties on the cooling rate (and therefore the particle size) and the powders can be sensitive to environmental degradation. Alloy compositions designed just for GA (as opposed to melt spinning) are necessary to produce an amorphous structure that can be crystallized to result in a fine structure with magnetic properties which are independent of particle size. The addition of titanium and carbon to the melt has been found to change the solidification process sufficiently to result in an ``overquenched`` state in which most of the powder size fractions have an amorphous component. Crystallization with a brief heat treatment produces a structure which has improved magnetic properties, in part due to the ability to use compositions with higher Fe contents without {alpha}-Fe precipitation. Results from magnetometry, magnetic force microscopy, and x-ray analyses will be used to contrast the microstructure, domain structure, and magnetic properties of this new generation of amorphous powders with their multiphase predecessors.

Sellers, C.H.; Branagan, D.J.; Hyde, T.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Lewis, L.H. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science; Panchanathan, V. [Magnequench International, Anderson, IN (United States)

1996-08-01

334

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

Microsoft Academic Search

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

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

2005-01-01

335

Cultural Vignette: Black Americans.  

ERIC Educational Resources Information Center

|Developed as part of a multicultural research project conducted in the San Diego Community College District, this booklet presents the findings of an eight-member research team about various elements of Black American culture and history. The booklet begins with a brief history of Black Americans from the time of the arrival of the first slaves…

Bell, Ida; And Others

336

Noncommutative Singular Black Holes  

NASA Astrophysics Data System (ADS)

In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t — r) dependence of solution in terms of the noncommutative parameter ?. In this setup, there is no black hole remnant at long times.

Hamid Mehdipour, S.

2010-11-01

337

Framing the black body  

Microsoft Academic Search

Black Letter Law - the basic principles of law embodied in the statutes and in the court records of a particular jurisdiction.\\u000aBlack Letter Law - a display of the works of three artists held at the Law School of the University of Sydney from October 22 to November 11, 1997.

J. Butler

1998-01-01

338

The Black Woman's Burden  

ERIC Educational Resources Information Center

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

Hayes, Dianne

2012-01-01

339

Black holes at LHC?  

Microsoft Academic Search

Strategies for identifying speculative mini black hole events (due to large extra dimensions) at future colliders are reviewed. Estimates for production cross sections, Hawking radiation, di-jet suppression and multi- mono-jet emission are surveyed. We further report on a class of effective entropy formulae that could lead to the formation of a final black hole remnant state, BHR. Such BHRs could

Ben Koch; Marcus Bleicher; Horst Stöcker

2007-01-01

340

Black Studies Year One.  

ERIC Educational Resources Information Center

|Though Dubois tried to begin a series of scientific studies on the Negro problem in America more than 70 years ago, only recently have attempts been made to present a true history of the Black man in institutions of higher learning. Until that time, the experience of the Black man was defined in Euro-American terms, or in most cases was…

Long, Richard A.

341

The Black Woman's Burden  

ERIC Educational Resources Information Center

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

Hayes, Dianne

2012-01-01

342

Humanism in Black Culture.  

ERIC Educational Resources Information Center

|We can identify black culture in terms of certain institutions and values which they share as members of an ethnic group, while recognizing that individual families and communities identify in important respects with other groups. The ascription of a humanistic character--defined as those values and institutions which black Americans have in…

Aschenbrenner, Joyce C.

343

On black hole entropy  

Microsoft Academic Search

Two techniques for computing black hole entropy in generally covariant gravity theories including arbitrary higher derivative interactions are studied. The techniques are Wald's Noether charge approach introduced recently, and a field redefinition method developed in this paper. Wald's results are extended by establishing that his local geometric expression for the black hole entropy gives the same result when evaluated on

Ted Jacobson; Gungwon Kang

1994-01-01

344

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

345

Sr-substituted hydroxyapatites for osteoporotic bone replacement.  

PubMed

Porous apatites, which during resorption can release in situ Sr ions, were prepared to associate an anti-osteoporotic action with the peculiar features of the inorganic phase constituting the bone. Sr-substituted hydroxyapatite (SrHA) powder was directly synthesized using the classical neutralization route, but including Sr ions, and characterized. The higher solubility of SrHA granules of 400-600 microm size, potentially usable as a bone filler, was assessed compared with that of analogous stoichiometric HA granules. The Sr released in synthetic body fluid became constant after 1 week. The Ca release is improved for SrHA compared with stoichiometric HA, due to the higher solubility of the first material. Porous scaffolds with micro-macro interconnected porosity, which mimic the morphology of the spongy bone, were prepared by the impregnation of cellulose sponges with suspensions of the powder and a specific sintering process. A compressive strength of 4.52+/-1.40 MPa was obtained for SrHA scaffolds characterized with 45 vol.% of porosity. Promising biomedical applications, such as resorbable bone filler or bone substitute releasing in situ Sr ions for a prolonged time, can be hypothesized for the SrHA materials when pathologies related with Sr deficiency are present. PMID:17618844

Landi, Elena; Tampieri, Anna; Celotti, Giancarlo; Sprio, Simone; Sandri, Monica; Logroscino, Giandomenico

2007-06-19

346

Rare 2-Substituted Purine Nucleosides.  

National Technical Information Service (NTIS)

This project is concerned with the synthesis of rare 2-substituted purine nucleosides with therapeutic potential against RNA viruses. The goals were to develop rational procedures for the synthesis of the target molecules discussed in the proposal. Synthe...

V. Nair

1986-01-01

347

Nucleophilic Substitution by Benzodithioate Anions.  

ERIC Educational Resources Information Center

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

Bonnans-Plaisance, Chantal; Gressier, Jean-Claude

1988-01-01

348

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

349

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

350

[Substitution therapy in drug addictions].  

PubMed

In France, so called "substitution treatments" for addiction are nicotine substitutes for tobacco dependence and buprenorphine, and methadone for opiate dependence. The word "substitution" participates to the uncertainty as to the objective of such treatments. From an addiction psychiatry perspective, these treatments are of interest as pharmacological treatments for maintenance of abstinence. In such a perspective they are not changing one substance of dependence for another. The goal is to reduce craving by low potential reinforcement medications. Conditions for success are a clarification of treatment goal with the patients, adequate dosing, and time. All medical doctors may prescribe buprenorphine for treatment of opiate dependence. Supervised daily dispensing in pharmacies is useful to increase compliance and collaboration, and avoid misuse and diversion. For tobacco dependence, nicotine patch must be clearly differentiated from other nicotine substitutes like gums and inhalers that have significant reinforcing effects. Because the patch is accessible without medical prescription, many patients are not sufficiently medically supervised and dropout frequently. For patients that cannot initially accept the behavioral changes associated to the goal of abstinence, it is legitimate to truly substitute them with less dangerous reinforcing substances. This possibility exists in France only for tobacco use that can be substituted to inhaled or chewed nicotine. It is possible that some reported misuse of buprenorphine and methadone are inadequate attempts to increase the reinforcing effects of these medications. PMID:12920942

Auriacombe, Marc; Fatseas, Mélina; Franques-Rénéric, Pascale; Daulouède, Jean-Pierre; Tignol, Jean

2003-06-15

351

The Black Family in American Economy: Black Capitalism.  

ERIC Educational Resources Information Center

|Black capitalism that is well planned and run is a source of enumerable benefits to the American society in general and to blacks in particular. It generates opportunities for blacks to perform in occupations which for many years were closed to them. For hundreds of years blacks have been despised and often looked down upon on account of the fact…

Ezeocha, Peter A.

352

Inheritance of Predorsal Black Stripe in Black Crappie  

Microsoft Academic Search

This study presents data on inheritance of the predorsal black stripe in black crappie Pomoxis nigromaculatus. Four progeny groups, obtained by crossing fish with certain phenotypes and of known origin, were investigated. Presence of the black stripe in all fish in two progeny groups, produced by crossing fish with and without the black stripe, indicated dominance of this trait. In

Boris Gomelsky; Steven D. Mims; Richard J. Onders; Noel D. Novelo

2005-01-01

353

Electrochemical performance of carbon onions, nanodiamonds, carbon black and multiwalled nanotubes in electrical double layer capacitors  

Microsoft Academic Search

This paper describes the electrochemical performance of carbon onions, nanodiamonds, carbon black and multiwalled nanotubes as electrodes in electrical double layer capacitors with organic electrolyte. Onions were formed by vacuum annealing of 5nm nanodiamond (ND) powder at 1200–2000°C with the goal to investigate the effect of carbon microstructure on specific capacitance and ion transport. In contrast to micro- or mesoporous

C. Portet; G. Yushin; Y. Gogotsi

2007-01-01

354

Analyses of Near-Field and Near-Regional Signals from the Black Thunder Mine.  

National Technical Information Service (NTIS)

In this report we present analyses of seismic data recorded at the Black Thunder coal strip mine in the Powder River Basin of Wyoming. The data (collected by Stump et al, 1996) are a set of recordings at distances of a few kilometers from mining activity ...

T. G. Barker K. L. McLaughlin

1998-01-01

355

Hypertension in blacks.  

PubMed

The excess of hypertension among blacks has been recognized since early in this century and explains a substantial portion of the black health disadvantage. In a cohort study begun in the 1970s, hypertension accounted for 20% of all-cause mortality among blacks, compared to 10% among whites. National data on trends in hypertension (140/90 mm Hg or treatment) prevalence from 1960 to 1990 suggest a decline from 44% to 32%, although differences in survey technique likely account for this pattern. During this period the prevalence ratio of black:white remained constant at 1.5, suggesting that secular trends in causal factors, if any, effected both groups equally. Recent data demonstrate a gradient in risk across the African diaspora, with standardized prevalences of 14% in West Africa and 26% in the Caribbean, compared to 33% in the US. This pattern parallels the gradient in known risk factors, with obesity alone accounting for a third of the excess in the US compared to Africa. Why the black excess of hypertension in the US? Despite widespread speculation, unique characteristics of hypertension among blacks have yet to be established. Consistent evidence demonstrates a similar impact of the known risk factors in all population groups. Epidemiologic evidence likewise suggests that a similar risk of complications exists with blood pressure elevation among blacks and whites, level for level. Although the genetic epidemiology of hypertension is still in its infancy, no clear cross-population differences are yet apparent. Pathophysiologic traits that are known to be part of the causal etiologic pathway have not been shown to vary across groups. Unique features of this condition among blacks are likely to be restricted to the different mixes and intensities of risk factors. In the absence of evidence to support the hypothesis, it is perhaps surprising that credence continues to be given to the notion of black exceptionalism. Am J PMID:9234837

Cooper, R; Rotimi, C

1997-07-01

356

Regular black holes: Electrically charged solutions, Reissner-Nordstroem outside a de Sitter core  

SciTech Connect

To have the correct picture of a black hole as a whole, it is of crucial importance to understand its interior. The singularities that lurk inside the horizon of the usual Kerr-Newman family of black hole solutions signal an endpoint to the physical laws and, as such, should be substituted in one way or another. A proposal that has been around for sometime is to replace the singular region of the spacetime by a region containing some form of matter or false vacuum configuration that can also cohabit with the black hole interior. Black holes without singularities are called regular black holes. In the present work, regular black hole solutions are found within general relativity coupled to Maxwell's electromagnetism and charged matter. We show that there are objects which correspond to regular charged black holes, whose interior region is de Sitter, whose exterior region is Reissner-Nordstroem, and the boundary between both regions is made of an electrically charged spherically symmetric coat. There are several types of solutions: regular nonextremal black holes with a null matter boundary, regular nonextremal black holes with a timelike matter boundary, regular extremal black holes with a timelike matter boundary, and regular overcharged stars with a timelike matter boundary. The main physical and geometrical properties of such charged regular solutions are analyzed.

Lemos, Jose P. S.; Zanchin, Vilson T. [Centro Multidisciplinar de Astrofisica - CENTRA, Departamento de Fisica, Instituto Superior Tecnico - IST, Universidade Tecnica de Lisboa - UTL, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia, 166, 09210-170, Santo Andre, Sao Paulo (Brazil); Coordenadoria de Astronomia e Astrofisica, Observatorio Nacional-MCT, Rua General Jose Cristino 77, 20921-400 Rio de Janeiro (Brazil)

2011-06-15

357

Black business transformation, black well-being, and public policy  

Microsoft Academic Search

This article examines public policy and social welfare issues related to a recent trend in black business ownership: the decline\\u000a of black-owned businesses in ‘traditional’ personal services serving a predominantly black clientele, and the corresponding\\u000a increase of black-owned businesses in ‘emerging’ capital- and knowledge-intensive fields. It is argued that, while the growth\\u000a of black business ownership in emerging fields is

Robert L. Boyd

1990-01-01

358

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

359

The Price of "Black Dominance."  

ERIC Educational Resources Information Center

|Discusses the harmful effects of stereotyping black males as athletes, noting that over-identification with athletes and the world of physical performance limits black children's development by discouraging academic achievement. Examines the negative influence of mass media focus on black athletes, rappers, and stylized ghetto blackness

Hoberman, John

2000-01-01

360

Mining coal on Black Mesa  

Microsoft Academic Search

Black Mesa is a remote highland in northeastern Arizona. Peabody Coal Company began surface mining operations on Black Mesa in 1970, leasing 64,868 acres from the Navajo and Hopi tribes. Approximately 12 million tons of coal are mined annually. The paper presented discussed Peabody's mining operation on Black Mesa. Topics detailed include transportation of the coal via the Black Mesa

Grow

1981-01-01

361

Blacks in the American Revolution  

ERIC Educational Resources Information Center

Re-examines the role played by blacks in the American Revolution, noting that blacks were a substantial portion (one-fifth) of the population, that about eight per cent of them were free, and that more free blacks lived in the South, that slavery existed in all 13 southern states, and that there were more slaves than free blacks living in the…

Toppin, Edgar A.

1975-01-01

362

The Price of "Black Dominance."  

ERIC Educational Resources Information Center

Discusses the harmful effects of stereotyping black males as athletes, noting that over-identification with athletes and the world of physical performance limits black children's development by discouraging academic achievement. Examines the negative influence of mass media focus on black athletes, rappers, and stylized ghetto blackness. Discusses…

Hoberman, John

2000-01-01

363

Topics in Black Hole Evaporation  

Microsoft Academic Search

Two major aspects of particle creation by gravitational fields of black holes are studied: the neutrino emission from rotating black holes; and interactions between scalar particles emitted by a black hole. The neutrino emission is investigated under three topics. The asymmetry of the angular dependence of neutrino emission from rotating black holes is calculated first. A low frequency analytic approximation

Denis Alan Leahy

1980-01-01

364

Ego Development and Black Identity  

Microsoft Academic Search

The relationship of ego development and Black identity formation was explored in thirty Black male and thirty Black female college students. The subjects were administered the Washington University Sentence Completion Test and the Racial Identity Attitude Scale. A significant inverse relationship was found between ego development and Black identity. This suggests that if an individual has strong ego, he or

Jacqueline Looney

1988-01-01

365

Blacks in the American Revolution  

ERIC Educational Resources Information Center

|Re-examines the role played by blacks in the American Revolution, noting that blacks were a substantial portion (one-fifth) of the population, that about eight per cent of them were free, and that more free blacks lived in the South, that slavery existed in all 13 southern states, and that there were more slaves than free blacks living in the…

Toppin, Edgar A.

1975-01-01

366

Lipid-based fat substitutes.  

PubMed

Fats and oils account for 38% of the total calories in the diet of Western populations, especially in the U.S. They provide the most concentrated source of energy, 9 kcal/g of a triacylglycerol molecule compared with 4 kcal/g provided by carbohydrate and protein. In response to consumer demands for low-calorie or calorie-free fats and their reluctance to give up the taste of fat, current research efforts have been directed toward the development of lipid-like fat substitutes. These fat substitutes contain the fatty acids found in conventional fats and oils, with all the physical and organoleptic properties of fats, but provide few or no calories in the diet. Some of the fat substitutes are modified triacylglycerols (glycerol backbone) with reduced digestion and absorption; others are digestible and nondigestible carbohydrate fatty acid esters and polyesters, respectively. Sucrose polyester (Olestra), a sucrose molecule esterified with six to either fatty acids, is the most studied of the lipid-based fat substitutes containing a carbohydrate backbone. If approved by the FDA, sucrose polyester will find application in almost all fat-containing foods. Specialty fats or fat substitutes targeted to certain individuals with special needs are being developed. Among these are the medium-chain triacylglycerols and structured lipids (glycerol backbone), or ¿nutraceuticals¿ with reduced absorption and medical applications. Enzyme biotechnology is another tool available to lipid chemists to selectively modify, esterify, transform, transesterify, and interesterify fats and oils or synthesize new lipids such as structured lipids of food, nutritional, and medical importance. These designer fats may be the trend in the future to produce medical lipids that do not occur normally in nature. The different types of lipid-based fat substitutes are reviewed with respect to their synthesis, analysis, metabolism, potential applications/uses, and the future of fat substitutes. PMID:8573281

Akoh, C C

1995-09-01

367

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

368

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

369

A multi-analytical approach for the characterization of powders from the Pompeii archaeological site.  

PubMed

Nine black powders found in Pompeii houses in three different types of bronze vessels (cylindrical theca atramentaria, unguentaries, and aryballoi) were characterized in order to assess a correspondence between the composition and the type of vessel and, possibly, to verify if these powders were inks or not. For the compositional characterization, a multi-analytical approach was adopted, which involved the use of scanning electron microscopy-energy dispersive X-ray, Fourier-transformed infrared spectroscopy, Raman, X-ray diffraction, electron paramagnetic resonance spectroscopy, thermogravimetric analysis, gas chromatography coupled with mass spectrometry (GC/MS), and pyrolysis GC/MS. Powders contained in cylindrical theca atramentaria form a homogeneous group, and their organic and inorganic compositions suggest that they were writing inks, while powders contained in unguentaries and aryballoi could have had several different uses, including writing inks and cosmetics. Furthermore, the composition profile of the powders found in cylindrical cases shows that, at 79?AD: , in Pompeii, carbon-based inks were still used for writing, and iron gall inks had not been introduced yet. PMID:21735063

Canevali, Carmen; Gentile, Paolo; Orlandi, Marco; Modugno, Francesca; Lucejko, Jeannette Jacqueline; Colombini, Maria Perla; Brambilla, Laura; Goidanich, Sara; Riedo, Chiara; Chiantore, Oscar; Baraldi, Pietro; Baraldi, Cecilia; Gamberini, Maria Cristina

2011-07-07

370

Characterization and structural analysis of zinc-substituted hydroxyapatites.  

PubMed

The substitution of Zn in hydroxyapatite (HA) crystals was examined via comprehensive characterization techniques. Nanosized HA crystals were synthesized by the wet chemical method in aqueous solutions including various amounts of Zn ions. X-ray fluorescent spectroscopy was used to examine the amount of Zn in the HA precipitates. Scanning electron microscopy and high-resolution transmission electron microscopy were employed to examine the effects of Zn on the morphology and crystal size of the precipitates. Conventional powder X-ray diffraction and the Rietveld refinement method revealed the apatite lattice parameters and phase changes with the inclusion of Zn. The results indicated that Zn ions partially substituted for Ca ions in the apatite structure. They were not simply adsorbed on the apatite surface or in the amorphous phase. The precipitates maintained the apatite phase up to a Zn:(Zn+Ca) ratio of 15-20 mol.% in the solution. Pure HA was well crystallized and the crystals had regular shapes, whereas the Zn-substituted apatite crystals became irregular and formed agglomerates. The lattice parameters, a and c, decreased at a Zn:(Zn+Ca) ratio of 10 mol.%. PMID:19446055

Ren, Fuzeng; Xin, Renlong; Ge, Xiang; Leng, Yang

2009-05-04

371

Thixoforming of Stellite Powder Compacts  

NASA Astrophysics Data System (ADS)

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

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

2007-04-01

372

Thixoforming of Stellite Powder Compacts  

SciTech Connect

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

Hogg, S. C. [Institute of PolymerTechnology and Materials Engineering, Loughborough University, Loughborough, LE11 3TU (United Kingdom); Atkinson, H. V. [Department of Engineering, University of Leicester, University Rd., Leicester LE1 7RH (United Kingdom); Kapranos, P. [Department of Engineering Materials, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

2007-04-07

373

Anion substitution in zinc chalcogenides.  

PubMed

Anion substitution effects on the structure and energy of zinc chalcogenides were studied with the semiempirical molecular orbital method MSINDO. Cyclic clusters of different sizes were chosen as model systems. The convergence of the bulk properties of the perfect clusters with increasing cluster size was tested. Single and multiple substitution of oxygen atoms in zinc oxide by sulfur and of sulfur atoms in zinc sulfide by oxygen served to determine the energetics of substitution for these two cases. It was found that the substitution of oxygen by sulfur in ZnO is easier than the substitution of sulfur by oxygen in ZnS in agreement with experimental results. The interaction between two oxygen atoms vs. two selenium atoms in zinc sulfide was investigated. Oscillations of the cluster energy in dependence of the distance between the two doping atoms were observed. These are explained by the relative sites of the doping atoms in the crystal lattice. The magnitude of the oscillations is smaller in ZnS:Se than in ZnS:O, because the difference between the anion radii of S2- and Se2- is smaller than between S2- and O2-. This is also reflected in the band gap. PMID:16691570

Jug, Karl; Tikhomirov, Viatcheslav A

2006-07-30

374

Black Holes and the Universe  

NASA Astrophysics Data System (ADS)

Part I. Black Holes: 1. What is a black hole?; 2. Around a black hole; 3. A gravitational abyss as an energy source; 4. The search for black holes; 5. Black holes and quanta; Part II. To The Bounds Of Infinity: 1. The Universe after the explosion; 2. Mechanics of the Universe; 3. The hot Universe; 4. Neutrino Universe or '... ino' Universe?; 5. At the frontiers of the known; Conclusion.

Novikov, Igor D.; Kisin, Vitaly

1995-09-01

375

Fabrication of calcium phosphate-calcium sulfate injectable bone substitute using chitosan and citric acid  

Microsoft Academic Search

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan solution as the liquid phase and tetra\\u000a calcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA) and calcium sulfate hemihydrate (CSH) powders as the solid\\u000a phase was prepared. Four groups containing different percentages (0–30%) of calcium sulfate hemihydrate (CSH, CaSO4 · 0.5H2O) were investigated. Initial setting times for IBS with CSH

Ho-Yeon Song; A. H. M. Esfakur Rahman; Byong-Taek Lee

2009-01-01

376

Black Widow Spider  

MedlinePLUS

... a group of spiders commonly known as cobweb spiders. The characteristic hourglass is located on the underside of the abdomen. Female black widows are dangerous and can bite and inject toxic venom. This is one in ...

377

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.

378

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

379

Black Holes and Inflation  

NASA Astrophysics Data System (ADS)

A model for black hole collapse and evaporation in which the black hole is supposed to be an excited state of one of the Planck black holes pervading the structure of spacetime is discussed. By assuming a Coleman-Weinberg gravitational effective potential for a scalar field inside the collapse matter, it is shown that the black hole state cannot be attained neither through bubble tunneling nor by the rolling down of the field.Translated AbstractSchwarze Löcher und InflationEin Modell des Collapses und der Verdampfung schwarzer Löcher wird diskutiert, wobei angenommen wird, daß schwarze Löcher angeregte Zustände der Planckschen schwarzen Löcher sind, verteilt über die Struktur der Raum-Zeit. Unter der Annahme eines effektiven Gravitationspotentials nach Coleman-Weinberg als skalares Feld innerhalb der collabierten Materie kann gezeigt werde, daß der schwarze Loch -Zustand weder durch bubble tunneling noch durch rolling down des Feldes angenommen werden kann.

González-Díaz, P. F.

380

The Black World Today  

NSDL National Science Digital Library

The Black World Today, the main purpose of which is to "chronicle the daily social, political, cultural and economic realities of Black communities and countries," contains daily news and views, as well as browsable archives of African and Canadian news. The "Black History Today" section, at present, contains a history of the Black Panther Party. There is also a report on the Anti-Racism Conference that took place October 26-28, 1996 in South Carolina, and an interview with Celerino Castillo, a former Drug Enforcement Administration official about the controversial charges of possible CIA involvement in the crack cocaine trade. The site includes a Java based chat room. Columnists for BWT include Manning Marable, Herb Boyd, and Earl Ofari Hutchinson, among others.

1996-01-01

381

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

382

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.

Welbon, William W. (Belleair, FL)

1983-01-01

383

Magnetic properties of polymer bonded nanocrystalline powder  

Microsoft Academic Search

Purpose: The aim of this paper was to develop a dielectromagnetic based on nanocrystalline Fe73.5Cu1Nb3Si13.5B9 powder bonded with organo-silicon polymer and to investigate the powder particle size and content of polymer response of the magnetic properties. Design\\/methodology\\/approach: The dynamic magnetic properties at the frequency range from 50 Hz up to 100 kHz of nanocrystalline iron based powder cores were measured

P. Gramatyka; R. Nowosielski; P. Sakiewicz

384

Particle Structures of Encapsulated Milkfat Powders  

Microsoft Academic Search

Emulsions of milkfat (cream or anhydrous butteroil), carbohydrate (sucrose, modified starch or all-purpose flour), nonfat dry milk and mono- and di-glycerides as emulsifying agents were prepared and spray dried, yielding free-flowing powders containing 400, 500 or 600 g\\/kg milkfat. Structural features of the powders were evaluated by optical and scanning electron microscopy. Powder particles were generally spherical in shape, with

C. I. Onwulata; P. W. Smith; P. H. Cooke; V. H. Holsinger

1996-01-01

385

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

386

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.

Not Available

1982-03-06

387

Dilatometry of attrition milled nanocrystalline titanium powders  

Microsoft Academic Search

The sintering behavior of nanosized titanium powders was investigated by dilatometry. The nanosized Ti powders (40nm) were produced by the attrition milling of micron sized Ti powders (12?m) in Ar atmosphere. Sintering was carried out in Ar atmosphere in the temperature range of 450–1250°C for nanosized Ti and 650–1250°C for micron sized Ti by heating at 10°C\\/min, up to the

Vikram V. Dabhade; B. B. Panigrahi; M. M. Godkhindi; T. R. Rama Mohan; P. Ramakrishnan

2006-01-01

388

Stroke in black Americans  

Microsoft Academic Search

Black Americans bear a disproportionate stroke burden in the United States compared with other racial and ethnic groups. Poor\\u000a stroke awareness, higher vascular risk factor burden, limited access to care, mistrust of the medical system, and inequities\\u000a in diagnostic testing and treatment usage may account for some of the disparity. In addition, blacks have historically been\\u000a under-represented in observational studies

Sean Ruland; Philip B. Gorelick

2005-01-01

389

Binary Black Hole Coalescence  

Microsoft Academic Search

A black hole is one of the most fascinating and enigmatic predictions of Einstein's theory of general relativity. Its interior\\u000a can have rich structure and is intrinsically dynamical, where space and time itself are inexorably led to a singular state.\\u000a The exterior of an isolated black hole is, on the other hand, remarkably simple, described uniquely by the stationary Kerr

Frans Pretorius

2009-01-01

390

Helical superconducting black holes.  

PubMed

We construct novel static, asymptotically five-dimensional anti-de Sitter black hole solutions with Bianchi type-VII(0) symmetry that are holographically dual to superconducting phases in four spacetime dimensions with a helical p-wave order. We calculate the precise temperature dependence of the pitch of the helical order. At zero temperature the black holes have a vanishing entropy and approach domain wall solutions that reveal homogenous, nonisotropic dual ground states with an emergent scaling symmetry. PMID:23003238

Donos, Aristomenis; Gauntlett, Jerome P

2012-05-22

391

Process for synthesizing compounds from elemental powders  

DOEpatents

A process for synthesizing intermetallic compounds from elemental powders. The elemental powders are initially combined in ratio a which approximates the stoichiometric composition of the intermetallic compound. The mixed powders are then formed into a compact which is heat treated at a controlled rate of heating such that an exothermic reaction between the elements is initiated. The heat treatment may be performed under controlled conditions ranging from a vacuum (pressureless sintering) to compression (hot pressing) to produce a desired densification of the intermetallic compound. In a preferred form of the invention, elemental powders of Fe and Al are combined to form aluminide compounds of Fe{sub 3}Al and FeAl.

Rabin, B.H.; Wright, R.N.

1990-01-01

392

Process for synthesizing compounds from elemental powders  

DOEpatents

A process for synthesizing intermetallic compounds from elemental powders. The elemental powders are initially combined in ratio a which approximates the stoichiometric composition of the intermetallic compound. The mixed powders are then formed into a compact which is heat treated at a controlled rate of heating such that an exothermic reaction between the elements is initiated. The heat treatment may be performed under controlled conditions ranging from a vacuum (pressureless sintering) to compression (hot pressing) to produce a desired densification of the intermetallic compound. In a preferred form of the invention, elemental powders of Fe and Al are combined to form aluminide compounds of Fe{sub 3}Al and FeAl.

Rabin, B.H.; Wright, R.N.

1990-12-31

393

Characterization of INCONEL alloy MA 6000 powder  

NASA Astrophysics Data System (ADS)

Mechanically alloyed powders of INCONEL* alloy MA 6000 have been characterized in order to understand the mechanical alloying process. Various analytical techniques including transmission electron microscopy, X-ray diffraction, electron microprobe analysis, and Auger electron spectroscopy were used to reveal the microstructural changes, chemical homogeneity, degree of mechanical working, and surface chemistry of powders during the powder processing. The current investigation has brought about a better understanding of the basic mechanism of the mechanical alloying process as well as a guideline for quality control of mechanically alloyed powder.

Kang, S. K.; Benn, R. C.

1987-06-01

394

Selective laser sintering of amorphous metal powder  

NASA Astrophysics Data System (ADS)

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 lower pulse energies due to its low melting point. The obtained results are compared with previous results from selective laser sintering of titanium powder.

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

2005-02-01

395

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

SciTech Connect

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

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

2012-08-15

396

Braneworld Black Holes  

NASA Astrophysics Data System (ADS)

In this thesis we investigate black holes in the Randall-Sundrum braneworld scenario. We begin with an overview of extra-dimensional physics, from the original proposal of Kaluza and Klein up to the modern braneworld picture of extra dimensions. A detailed description of braneworld gravity is given, with particular emphasis on its compatibility with experimental tests of gravity. We then move on to a discussion of static, spherically symmetric braneworld black hole solutions. Assuming an equation of state for the ``Weyl term'', which encodes the effects of the extra dimension, we are able to classify the general behaviour of these solutions. We then use the strong field limit approach to investigate the gravitational lensing properties of some candidate braneworld black hole solutions. It is found that braneworld black holes could have significantly different observational signatures to the Schwarzschild black hole of standard general relativity. Rotating braneworld black hole solutions are also discussed, and we attempt to generate rotating solutions from known static solutions using the Newman-Janis complexification ``trick''.

Whisker, Richard

2008-10-01

397

Microwave absorption properties of Ce-substituted M-type barium ferrite  

NASA Astrophysics Data System (ADS)

Ce-substituted barium ferrite with chemical composition BaCe0.05Fe11.95O19 has been prepared by the citrate sol-gel method. The phase composition of BaCe0.05Fe11.95O19 was characterized by X-ray powder diffraction analysis (XRD). The complex permittivity and complex permeability, microwave absorption properties of the resulting powder were measured by the transmission/reflection coaxial line method in the range of 8-13 GHz. The results show that the resulting powder has a minimum reflection loss value of - 37.4 dB at 12.8 GHz with a matching thickness of 3.5 mm.

Chang, Sun; Kangning, Sun; Pengfei, Chui

2012-03-01

398

How Black are Black Hole Candidates?  

NASA Astrophysics Data System (ADS)

How Black Are Black Hole Candidates? Darryl J. Leiter, FSTC, Charlottesville, VA, Stanley L. Robertson, Dept of Physics, Southwestern Oklahoma State University In a paper submitted to ApJ in 2002 (astro-ph/0208333) we review and extend previously discussed observational evidence (Robertson and Leiter, ApJ, vol 565, pg 447) which supports the existence of intrinsically magnetized central objects in GBHC and show that it is consistent with a new class of solutions of the Einstein field equations of General Relativity. Based on a strict adherence to the Principle of Equivalence, the new solutions dynamically prevent the time-like geodesics of physical matter from becoming null on trapped surfaces of infinite red shift. We show that the new solutions to the Einstein field equations represent the existence of highly red shifted, magnetospheric, eternally collapsing objects (MECO) which do not have trapped surfaces leading to event horizons. They emerge from the fact that the structure and radiation transfer properties of the energy-momentum tensor on the right hand side of the Einstein field equations must have a form that is dynamically consistent with the strict Principle of Equivalence requirement. Since the highly redshifted MECO have lifetimes which are many orders of magnitude greater than a Hubble time, they replace black hole models with an elegant, consistent, and unified framework for understanding the broad range of observations associated with GBHC and active galactic nuclei.

Leiter, Darryl; Robertson, Stanley

2003-04-01

399

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

400

Comparison of electrostatic fine powder coating and coarse powder coating by numerical simulations  

Microsoft Academic Search

Powder coating has several key advantages over liquid coating, and fine powder coating makes the surface finish quality comparable with liquid coating. This work reports on the numerical simulation of a fine powder-coating process in comparison with coarse powder coating, using a commercial computational fluid dynamic code, Fluent v6.1. The purpose of the study is to understand the gas and

U. Shah; C. Zhang; J. Zhu

2006-01-01

401

Preparation of ceramic powders based on titanium nitride on heating commercial titanium powder in air  

Microsoft Academic Search

Theoretical bases arepresented for preparing ceramic powders based on titanium and aluminum nitrides. The basic advantages\\u000a are formulated for self-propagating high-temperature synthesis of metal nitride powders in air compared with known preparation\\u000a methods. The main results are summarized and presented for preparing titanium nitride powder with combustion in air of cylindrical\\u000a and conical specimens of commercial titanium powder. The effect

Yu. I. Strokova; A. A. Gromov; V. I. Vereshchagin

2008-01-01

402

[Temporary tatooing: black henna or harkous?].  

PubMed

Contact sensitization to natural henna (Lawsonia inermis) long used as a skin dye in powder or paste form has rarely, if ever, been observed. Recently a number of anaphylactoid reactions to PPD contained in paints used for temporary tattoos have been described. The purpose of this article is to present 8 cases involving 4 children and 4 adults who developed contact dermatitis after temporary tattoo using "harkous" that contains no henna. The authors review the literature about temporary tattooing. "Harkous" is a mixture of nut gall and clove to which PPD is sometimes added. Many reports have described cases of contact dermatitis due to "black henna". Most of these cases have involved tourists returning from trips. PMID:20025192

Kharfi, M; El Fekih, N; Zayan, F; Mrad, S; Kamoun, M R

2009-10-01

403

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

Microsoft Academic Search

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

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

2005-01-01

404

Properties of nickel base precipitation-hardening alloy powders and sintered parts from such powders  

Microsoft Academic Search

In Table 1 are listed the chemical compositions of the alloy powders investigated. The fine fraction (< 0.063 mm) content of the powders varied from 50 to 70 wt. %. The alloy KhN55VMTFKYu was chosen for determinations of the presence and character of solid solution strengthening phases. The powder of this alloy was pressed isostatically under a pressure of 150

I. A. Lavrent'ev; R. P. Shchegoleva

1974-01-01

405

Influences of different powders on the characteristics of particle charging and deposition in powder coating processes  

Microsoft Academic Search

This experimental study investigated the influences of two different powder systems (coarse and ultrafine) on particle charging and deposition characteristics during electrostatic powder coating processes. Results disclosed that, despite their differences in particle sizes, the two powders behave similarly in deposition process, commonly resulting in a cone-shaped deposited pattern in the inner portion of the substrate and an increase of

Xiangbo Meng; Hui Zhang

2009-01-01

406

Microwave absorbing properties of Co-substituted Ni2W hexaferrites in Ka-band frequencies (26.5-40 GHz)  

Microsoft Academic Search

Magnetic (static, high-frequency) and microwave-absorbing properties of Co-substituted Ni2W hexaferrites are investigated in the frequency range of Ka-band (26.5-40 GHz). The powders of composition BaNi2-XCoXFe16O27 are prepared by calcining at 1250°C, where the substitution ratio x was varied from 0.0 to 1.4. With the calcined powders, the composite specimens are prepared using the silicon rubber as a matrix material. Vibrating

Yong-Jin Kim; Sung-Soo Kim

2002-01-01

407

Magnetic and microwave absorbing properties of Ti and Co substituted M-hexaferrites in Ka-band frequencies (26.5?~?40 GHz)  

Microsoft Academic Search

Magnetic and microwave absorbing properties of M-hexaferrites have been investigated in Ka-band frequencies (26.5?~?40 GHz)\\u000a with substitution of Ti+4 and Co+2 ions for Fe+3 sites. The powders of composition BaFe12-2xTixCoxO19 were prepared by conventional ceramic processing, where the substitution ratio x was varied from 0.0 to 2.0. With the calcined\\u000a powders, polycrystalline bulk and composite sheet samples were prepared for the

Yong-Jin Kim; Sung-Soo Kim

2010-01-01

408

Black Holes in String Theory  

NASA Astrophysics Data System (ADS)

This is a set of introductory lecture notes on black holes in string theory. After reviewing some aspects of string theory such as dualities, brane solutions, supersymmetric and non-extremal intersection rules, we analyze in detail extremal and non-extremal 5d black holes. We first present the D-brane counting for extremal black holes. Then we show that 4d and 5d non-extremal black holes can be mapped to the BTZ black hole (times a compact manifold) by means of dualities. The validity of these dualities is analyzed in detail. We present an analysis of the same system in the spirit of the adS/CFT correspondence. In the "near-horizon" limit (which is actually a near inner-horizon limit for non-extremal black holes) the black hole reduces again to the BTZ black hole. A state counting is presented in terms of the BTZ black hole.

Skenderis, Kostas

409

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Butyl acrylate, polymer with substituted methyl styrene, methyl...Substances § 721.6920 Butyl acrylate, polymer with substituted methyl styrene, methyl...substance identified as butyl acrylate, polymer with substituted methyl styrene,...

2013-07-01

410

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

411

The preparation and properties of glass powder reinforced epoxy resin  

Microsoft Academic Search

A sealing composites were prepared by mixing superfine glass powder and epoxy resin. The effect of active agent (stearate) on glass powder size and size distribution and the effect of surface treatment of the glass powder on the microstructure and the mechanical properties of glass powder\\/epoxy composites were investigated. Glass powder size was measured using a laser particle size analyzer.

Haifeng Wang; Wenjue Han; Haibing Tian; Yimin Wang

2005-01-01

412

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

413

Dissection of a continuous distribution: red cell galactokinase activity in blacks.  

PubMed Central

A significant difference between blacks and whites in the distribution of red cell galactokinase (GALK) has been found by Tedesco et al. [2]. From the shapes of the distributions, it was inferred that whites are essentially all homozygous for one allele (GALKA), but blacks are polymorphic. A second allele (GALKP), for lower GALK activity, is presented at high frequency in blacks but rare or absent in whites. This paper presents a method which, assuming the genetic model presented, estimates the genotype composition of the black sample. We make some reasonable biochemical assumptions and fit a mixture of three normal distributions to the black data to obtain an estimate of p, the frequency of GALKA in blacks. The fit of the model to the data is excellent and the best estimate of p is .217 +/- .025. Since admixture of white genes in blacks from the United States is known to be about 20%, the value of p implies that virtually all GALKA alleles were introduced by admixture, and that the ancestral black population was monomorphic for GALKP. If whites are indeed monomorphic for GALKA, they differ from unmixed blacks by a full gene substitution at the locus for GALK.

Spielman, R S; Harris, H; Melliman, W J; Gershowitz, H

1978-01-01

414

Skin Substitutes and Wound Healing  

Microsoft Academic Search

Medical science has vastly improved on the means and methods available for the treatment of wounds in the clinic. The production and use of various types of skin substitutes has led to dramatic improvements in the odds of survival for severely burned patients, but they have also shown promise for many other applications, including cases involving chronic wounds that are

F. A. Auger; D. Lacroix; L. Germain

2009-01-01

415

Austronesian Nasal Substitution: A Survey  

Microsoft Academic Search

Nasal substitution, which replaces a base-initial obstruent with the homorganic nasal under pre²xation, is arguably the most prominent morphonological process seen in Austronesian languages, as it is an active part of the verbal morphology of most languages of the Philippines and western Indonesia, as well as Malagasy, Chamorro, and Palauan. Although a comparative overview of this process was provided by

Robert Blust

2004-01-01

416

Assessment of asbestos insulation substitutes  

Microsoft Academic Search

A state-of-the-art study of asbestos insulation alternatives has been conducted to identify the best substitute material for steam lines in power plants. A survey of utilities across the nation showed that calcium silicate is the most commonly employed material today, followed by mineral wool, fiberglass, and ceramic fibers. However, the calcium silicate was found to be dusty and to become

J. D. Fourroux; R. L. Jr. Frank; T. W. Jr. Newberry

1990-01-01

417

ADMISSIBLE SUBSTITUTIONS IN SEQUENT CALCULI  

Microsoft Academic Search

For first-order classical logic a new notion of admissible substitution is defined. This notion allows optimizing the procedure of the application of quantifier rules when logical inference search is made in sequent calculi. Our objective is to show that such a computer-oriented sequent technique may be created that does not require a preliminary skolemization of initial formulas and that is

A. V. Lyaletski

418

Light attrition of uranium dioxide powder  

Microsoft Academic Search

Sinterable uranium dioxide powders prepared through the ammonium diuranate route are prone to agglomeration causing difficulty in compaction and sintering. UO2 powder after light (short duration and low ball to charge ratio) attrition has been found to require lower compaction pressures and resulted in higher yields after sintering and finish grinding. Details of an in-house-built attritor are given. Experimental results

Palanki Balakrishna; B Narasimha Murty; D. V Ratnam; M Anuradha; C Ganguly

2003-01-01

419

Preparation of copper powder by glycerol process  

Microsoft Academic Search

A simple, least energy intensive, efficient, low temperature chemical process for the production of copper powder of narrow size distribution is described. It involves reduction of copper salts by glycerol under atmospheric conditions at a temperature below 240°C. The powders produced by this process have been characterized by X-ray diffraction, chemical composition, BET surface area analysis and scanning electron microscopy.

Amit Sinha; B. P Sharma

2002-01-01

420

Creep densification of copper powder compact  

Microsoft Academic Search

Densification of metal powder under high temperature processing was investigated. Experimental data were obtained for copper powder under hot isostatic pressing, hot pressing and uniaxial creep compression. Theoretical calculations from the constitutive models by McMeeking and co-workers were compared with the experimental data. The agreements between experimental data and theoretical calculations are reasonably good when hydrostatic stress is dominant, but

M. C. Song; H. G. Kim; K. T. Kim

1996-01-01

421

Thermal plasma chemical synthesis of powders  

SciTech Connect

Thermal plasma processing has been increasingly used to synthesize submicron powders of high-purity ceramics and metals. The high temperatures generated with the plasma provide a vapor phase reaction zone for elements with high boiling points and refractory materials. An overview is presented on the general plasma technology used in synthesis and on the properties of plasma powders.

Vogt, G.J.; Newkirk, L.R.

1985-01-01

422

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

423

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

424

Powder Lubricant Based on Molybdenum Disulfide.  

National Technical Information Service (NTIS)

This patent introduces a powder-like lubricant of molybdenum disulfide for machining of a cutting tool. To improve the cutting properties of the tool and increase its life, an addition of 15-25 percent sulfur to the powder lubricant is recommended.

S. V. Grekov

1969-01-01

425

PLANT TRIALS FOR POWDER PRIMING OF SMC  

Microsoft Academic Search

Based on the information generated at GM R&D Center, six SMC formulations were developed and produced by SMC suppliers and subsequently molded into automotive body panels for powder primer application readiness tests. The panels were evaluated in the lab for shrinkage, moisture absorption, adhesion to the conductive coating, and powder application. Based on the results, all six formulations were approved

Hamid G. Kia; Bhavesh Shah; Christina Hicks

426

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

427

Sinterable Powders from Laser Driven Reactions.  

National Technical Information Service (NTIS)

Extremely fine, uniform ceramic powders have been synthesized from SiH4 NH3 and C2H4 gas phase reactants that are heated by absorbing optical energy emitted from a CO2 laser. Resulting Si, Si3N4 and SiC powders have been characteristics in terms of parame...

J. S. Haggerty

1982-01-01

428

Shock consolidation of powders: theory and experiment  

Microsoft Academic Search

A recently proposed model of shock consolidation of powders quantitatively predicts regimes of input energy and shock duration required to produce well-bonded compacts. A growing data base from shock experiments in which the shock wave and powder parameters of importance are controlled allows evaluation of the model. Rapidly solidified crystalline AISI 9310, and microcrystalline Markomet 3.11, as well as amorphous

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

1984-01-01

429

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

430

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

431

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

432

Composite metal foams processed through powder metallurgy  

Microsoft Academic Search

A new closed cell composite metal foam has been produced using a powder metallurgy technique. The composite foams are processed by filling the vacancies between densely packed steel hollow spheres with steel powder and sintering them into a solid cellular structure. Three sets of samples have been processed, two of carbon steel and one of stainless steel. The relative densities

B. P. Neville; A. Rabiei

2008-01-01

433

Modeling nonelectrostatic and electrostatic powder coating  

Microsoft Academic Search

The effect of particle size, density, charge and air velocity on transfer efficiency, evenness and separation of mixtures during powder coating was investigated using modeling and experimentation. Electrostatic and nonelectrostatic coating was tested using 28, 234 and 342?m NaCl and 195?m starch powders. Transfer efficiency increased as particle size, density or charge increased or as air velocity decreased. Evenness increased

Shantanu Yousuf; Sheryl A. Barringer

2007-01-01

434

Poisoning with Veratrum-containing Sneezing Powders  

Microsoft Academic Search

1 Nine cases of accidental poisoning of children with sneezing powder are reported. Symptoms, besides sneezing, included gastrointestinal disturbances and syncope, whilst examination demonstrated bradycardia and hypotension.2 The powder, as supplied, carried no information on its constituents but Veratrum alkaloids were identified on analysis. The signs and symptoms observed were compatible with poisoning from these compounds.3 As a result of

P. Carlier; M.-L. Efthymiou; R. Garnier; J. Hoffelt; E. Fournier

1983-01-01

435

Chemistry and Technology of Metal Powders.  

National Technical Information Service (NTIS)

A new process for the preparation of finely divided metal powders has been used in preliminary studies on a number of metal powders. The metals that were examined were found to exhibit far superior reactivity to that described in the literature for these ...

R. D. Rieke

1977-01-01

436

Powder-lubricated piston ring development  

SciTech Connect

The overall objective of this program was to demonstrate the feasibility of a new particulate lubrication concept for reducing piston ring/cylinder liner wear in coal-water slurry-fueled diesels by replacing the present oil-lubricated system with powder lubrication that would utilize coal ash, either alone or in combination with another powder. The feasibility of this particular lubrication concept for reducing ring/liner wear was demonstrated in a series of experiments utilizing redesigned and properly selected components. Wear performance for suitable ring/liner materials lubricated with a powder that incorporates the abrasive ash particles was evaluated in terms of load capacity, friction, and rate of wear for the best combination of ring design, ring and liner materials, and powder constituents. In addition, the use of a powder-lubricated system in the upper portion of the cylinder isolated the particulates from the lower portions of the engine, thus further reducing engine wear. (VC)

Heshmat, H.

1991-06-01

437

Nanostructured GGG powders via gel combustion  

NASA Astrophysics Data System (ADS)

Polycrystalline nano-sized gadolinium gallium garnet (Gd3Ga5O12, GGG) powders were synthesized via a gel combustion method from a mixed solution of Ga(NO3)3, Gd(NO3)3 and citric acid. The evolution of phase composition and micro-structure of the powders were characterized by X-ray powder diffraction, thermogravimetry/differential thermal analysis and scanning electron microscopy. Well-crystallized, single phase GGG nano-sized powders could be obtained at the calcining temperature as low as 750 °C for 2 h. No any intermediate phases formed during the calcining process. The resulting powders were well dispersed and had a relatively narrow size distribution with an average particle size of approximately 30 50 nm.

Li, Xianxue; Hu, Zhang-Gui; Li, Jiangtao

2007-03-01

438

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)

1982-01-01

439

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, L.G.

1979-08-29

440

Powder-lubricated piston ring development  

NASA Astrophysics Data System (ADS)

The overall objective of this program was to demonstrate the feasibility of a new particulate lubrication concept for reducing piston ring/cylinder liner wear in coal-water slurry-fueled diesels by replacing the present oil-lubricated system with powder lubrication that would utilize coal ash, either alone or in combination with another powder. The feasibility of this particular lubrication concept for reducing ring/liner wear was demonstrated in a series of experiments utilizing redesigned and properly selected components. Wear performance for suitable ring/liner materials lubricated with a powder that incorporates the abrasive ash particles was evaluated in terms of load capacity, friction, and rate of wear for the best combination of ring design, ring and liner materials, and powder constituents. In addition, the use of a powder-lubricated system in the upper portion of the cylinder isolated the particulates from the lower portions of the engine, thus further reducing engine wear.

Heshmat, H.

1991-06-01

441

Branched aliphatic alkanes with quaternary substituted carbon atoms in modern and ancient geologic samples  

Microsoft Academic Search

A pseudohomologous series of branched aliphatic alkanes with a quaternary substituted carbon atom (BAQCs, specifically 2,2-dimethylalkanes and 3,3- and 5,5-diethylalkanes) were identified in warm (65°C) deep-sea hydrothermal waters and Late Cretaceous black shales. 5,5-Diethylalkanes were also observed in modern and Holocene marine shelf sediments and in shales spanning the last 800 million years of the geological record. The carbon number

Fabien Kenig; Dirk-Jan H. Simons; David Crich; James P. Cowen; Gregory T. Ventura; Tatiana Rehbein-Khalily; Todd C. Brown; Ken B. Anderson

2003-01-01

442

Black Hole Flight Simulator  

NASA Astrophysics Data System (ADS)

Black Hole Flight Simulator The Black Hole Flight Simulator (BHFS) is interactive software that works in real time either on a PC, or in a multi-processed multi-pipe full dome environment such as the new Gates Planetarium at the Denver Museum for Nature and Science (DMNS). The BHFS is intended to simulate realistic flight around and into black holes, as if one were piloting a spaceship, and features a multitude of special and general relativistic effects, including lensing, redshifting, and time dilation. The BHFS currently incorporates a complete implementation of the Reissner-Nordström geometry of a spherical charged black hole, including its connections inside the horizon to parallel universes, wormholes, white holes, and other universes. The BHFS was developed while the author was on sabbatical with the DMNS in 2001/2, and will be used to generate black hole graphics in a TV show and an associated large format high resolution dome show currently in production in collaboration with Nova-PBS and the DMNS, for launch in 2005, the centenary of Einstein's annus mirabilis.

Hamilton, A. J. S.

2004-05-01

443

The thermochromic vanadium dioxide. I. Role of stresses and substitution on switching properties  

SciTech Connect

The monoclinic [Leftrightarrow] tetragonal transition occurring at 341 K for VO[sub 2] vanadium dioxide and the corresponding switching of the optical properties can be affected in various ways by thermal treatments, substitution, and pressure. The transition in pure or substituted powdered samples is characterized by thermal analysis (DSC), X-ray (XRD) and neutron (NRD) diffractions, and infrared spectroscopy (IR). The influence of pressure on the transition is discussed from neutron diffraction experiments at high pressure. The anisotropic compressibility coefficients in the monoclinic and tetragonal phases are considered. Some kinetic effects close to [Tc], the transition temperature, have been observed by X-ray diffraction. The influences of pressure and substitution on the transition are then interpreted from a classical description of the chemical bonds in VO[sub 2]. 38 refs., 8 figs., 4 tabs.

Rakotoniaina, J.C. (Universite de Toulon et du Var, La Garde (France) Universite de Provence, Marseille (France)); Mokrani-Tamellin, R.; Gavarri, J.R. (Universite de Toulon et du Var, La Garde (France)); Vacquier, G.; Casalot, A. (Universite de Provence, Marseille (France)); Calvarin, G. (Ecole Centrale des Arts et Manufactures, Chatenay-Malabry (France))

1993-03-01

444

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

2010-10-19

445

Strengths of Black Families: A Black Community's Perspective.  

ERIC Educational Resources Information Center

Research on Black families should use a nondeviant perspective. Strengths in Black families, such as kinship, work orientation, adaptability of family roles, achievement, and religious orientation, are too often overlooked. (JAC)

Royse, David D.; Turner, Gladys T.

1980-01-01

446

Improving powder flow properties of a cohesive lactose monohydrate powder by intensive mechanical dry coating.  

PubMed

The objective of this study was to improve the cohesive lactose powder flowability. A cohesive lactose monohydrate powder was processed in either a tumbling blender or an intensive mechanical processor with either magnesium stearate or fumed silica. No substantial changes in particle size were detected by laser diffraction following either treatment. The untreated lactose sample exhibited very poor powder flow. Only limited improvements in powder flowability were indicated after the tumbling blending, intensive mechanical processing with the fumed silica or without additives. However, the intensive mechanical processing of the lactose sample with magnesium stearate demonstrated exceptionally large increases in both poured and tapped density as well as notable improvements in all powder flowability indicators examined. Our findings support the use of intensive mechanical processing technique as an effective method to coat cohesive pharmaceutical powders with selected additives, modify the surface nature of the particles, reduce the interparticle cohesive forces and hence improve powder flowability. The subtle differences in powder flow behaviour of lactose samples between the untreated and tumbling blended powders with magnesium stearate were only detected by the powder rheometer using its dynamic mode, indicating its potential advantages over traditional powder flow characterisation approaches. PMID:19795479

Zhou, Qi; Armstrong, Brian; Larson, Ian; Stewart, Peter J; Morton, David A V

2010-02-01

447

C?H Bond Activation by Pd-substituted CeO[subscript 2]: Substituted Ions versus Reduced Species  

SciTech Connect

Substituted metal oxides containing ionic species have been attracting a great deal of attention because of their potential ability to reduce the usage of precious metals in heterogeneous catalysts. We investigate Pd-substituted CeO{sub 2} for C-H bond activation reactions including the partial oxidation and dry reforming of CH{sub 4}. This catalyst has been previously studied for CO oxidation, NO{sub x} reduction, and the water-gas shift reaction. Pd-substituted CeO{sub 2}, Ce{sub 1-x}Pd{sub x}O{sub 2-{delta}}, was prepared as a powder with high surface area and a hollow sphere morphology using ultrasonic spray pyrolysis. The catalysts were extensively characterized using synchrotron X-ray diffraction and other techniques, confirming phase pure samples up to 10 mol % Pd substitution. Ce{sub 0.95}Pd{sub 0.05}O{sub 2-{delta}} was found to be active for partial oxidation of CH{sub 4} around 500 C and higher. Our studies, including postcatalytic synchrotron diffraction, suggest that the single-phase Ce{sub 1-x}Pd{sub x}O{sub 2-{delta}} material is not the active species and that catalysis occurs instead over the reduced two-phase Pd{sup 0}/CeO{sub 2}. This observation has been further confirmed by verifying the activity of the reduced Pd{sup 0}/CeO{sub 2} catalysts for ethylene hydrogenation, a reaction that is known to require Pd{sup 0}.

Misch, Lauren M.; Kurzman, Joshua A.; Derk, Alan R.; Kim, Young-Il; Seshadri, Ram; Metiu, Horia; McFarland, Eric W.; Stucky, Galen D. (Yeungnam); (UCSB)

2012-02-07

448

The black student athlete: The colonized black body  

Microsoft Academic Search

This article views the black student athlete as colonized Black Body. It uses an internal colonial model to place the experiences\\u000a black student athletes encounter at predominantly white National Collegiate Athletic Association (NCAA) Division I Institutions\\u000a into a broader theoretical framework. This theoretical approach draws upon the similarities that exist between black student\\u000a athletes and internally colonized people. The conclusion

Billy Hawkins

1995-01-01

449

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

450

Aqueous oxidation of substituted dihydroxybenzenes by substituted benzoquinones.  

PubMed

Strict anaerobic techniques, HPLC, and spectrophotometry are employed to explore rates of reaction between a series of substituted benzoquinone oxidants and substituted dihydroxybenzene reductants, which represent important redox-active moieties within natural organic matter (NOM). Benzoquinones and dihydroxybenzenes that lack electron-withdrawing substituents exhibit reversible reactions within the acidic range of natural waters. Initial rates for reversible reactions are proportional to [H+]-1, attributable to the greater reactivity of monoprotonated versus diprotonated dihydroxybenzene molecules. Reversible reactions are generally faster for pairs having higher thermodynamic driving force. Concentrations in reversible reactions eventually reach plateau values, which coincide with expected values calculated using standard reduction potentials. If a reactant benzoquinone possesses an electron-withdrawing substituent, reaction progress falls short of expected values. If a product benzoquinone possesses an electron-withdrawing substituent, reaction progress extends beyond what is thermodynamically predicted. Electron-withdrawing substituents raise the susceptibility of benzoquinones to side reactions such as the Michael addition reaction. PMID:16786688

Uchimiya, Minori; Stone, Alan T

2006-06-01

451

Improved critical current density in ex situ processed carbon-substituted MgB2 tapes by Mg addition  

NASA Astrophysics Data System (ADS)

We have studied the effect of planetary ball-milling of filling powder with mineral oil on the carbon substitution and the critical current density (Jc) of Fe-sheathed MgB2 tapes fabricated through an ex situ process in a powder-in-tube (PIT) technique. Although tapes using powder with oil treatment show weak coupling, the Jc properties of those tapes are enhanced due to carbon substitution for boron. The ball-milling treatment with the oil on the filling powder with Mg addition further enhances the Jc property of tapes. The Jc values of the tapes reach about 9 kA cm-2 at 4.2 K and 10 T. The ball-milling produces a fresh clean surface by the grinding of large grains with a damaged surface and promotes a carbon substitution reaction. Mg addition compensates for the deviation in composition which occurs in the reaction. Some of the boron which is released from MgB2 at the reaction can act as an obstacle to the supercurrent path. The additional Mg consumes the boron at the formation of MgB2 and improves the grain coupling.

Fujii, H.; Ozawa, K.; Kitaguchi, H.

2012-06-01

452

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

453

Rotating black droplet  

NASA Astrophysics Data System (ADS)

We construct the gravitational dual, in the Unruh state, of the "jammed" phase of a CFT at strong coupling and infinite N on a fixed five-dimensional rotating Myers-Perry black hole with equal angular momenta. When the angular momenta are all zero, the solution corresponds to the five-dimensional generalization of the solution first studied in [1]. In the extremal limit, when the angular momenta of the Myers-Perry black hole are maximum, the Unruh, Boulware and Hartle-Hawking states degenerate. We give a detailed analysis of the corresponding holographic stress energy tensor for all values of the angular momenta, finding it to be regular at the horizon in all cases. We compare our results with existent literature on thermal states of free field theories on black hole backgrounds.

Fischetti, Sebastian; Santos, Jorge E.

2013-07-01

454

Black spot of potatoes  

Microsoft Academic Search

Summary  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a Black spot was produced in the laboratory in a reversible reaction by manipulating cell turgor.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a The amount of air used in cooling potatoes affected black spot.\\u000a \\u000a \\u000a \\u000a \\u000a 3. \\u000a \\u000a The addition of moisture to the ventilating air used in cooling potatoes lowered the incidence of black spot.\\u000a \\u000a \\u000a \\u000a \\u000a 4. \\u000a \\u000a Skin characteristics such as lenticel and periderm structure indicate an explanation

R. L. Sawyer; G. H. Collin

1960-01-01

455

Solve for X: Black mothers+black boys=X  

Microsoft Academic Search

Can mothers teach their sons how to become men? In recent years, that question has been discussed and debated on Black radio, in Black magazines, in workshops and conferences, and in Black households across this nation. Yet, there is little research to inform those who participate in this argumentative discourse. To this end, this present article is a summary of

Lawson Bush

2000-01-01

456

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

457

Slowly balding black holes  

SciTech Connect

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 N{sub B}=e{Phi}{sub {infinity}}/({pi}c({h_bar}/2{pi})), where {Phi}{sub {infinity}}{approx_equal}2{pi}{sup 2}B{sub NS}R{sub NS}{sup 3}/(P{sub NS}c) 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. [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907-2036 (United States); Department of Physics, Stanford University, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)

2011-10-15

458

21 CFR 866.1640 - Antimicrobial susceptibility test powder.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Antimicrobial susceptibility test powder. ...Diagnostic Devices § 866.1640 Antimicrobial susceptibility test powder. (a) Identification. An antimicrobial susceptibility test powder...

2010-04-01

459

21 CFR 866.1640 - Antimicrobial susceptibility test powder.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Antimicrobial susceptibility test powder. ...Diagnostic Devices § 866.1640 Antimicrobial susceptibility test powder. (a) Identification. An antimicrobial susceptibility test powder...

2009-04-01

460

21 CFR 872.6660 - Porcelain powder for clinical use.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Porcelain powder for clinical use. 872.6660...Miscellaneous Devices § 872.6660 Porcelain powder for clinical use. (a) Identification. Porcelain powder for clinical use is...

2009-04-01

461

21 CFR 872.6660 - Porcelain powder for clinical use.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Porcelain powder for clinical use. 872.6660...Miscellaneous Devices § 872.6660 Porcelain powder for clinical use. (a) Identification. Porcelain powder for clinical use is...

2010-04-01

462

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

463

Black Television: Avenue of Power  

ERIC Educational Resources Information Center

Analyzes a few of the prominent issues in black television, examining public television, commercial television, black ownership of stations, cable television, and some projections for the future. (Author/JM)

Douglas, Pamela

1973-01-01

464

General black holes, untwisted  

NASA Astrophysics Data System (ADS)

We use solution-generating techniques to construct interpolating geometries between general asymptotically flat, charged, rotating, non-extremal black holes in four and five dimensions and their subtracted geometries. In the four-dimensional case, this is achieved by the use of Harrison transformations, whereas in the five-dimensional case we use STU transformations. We also give the interpretation of these solution-generating transformations in terms of string (pseudo)-dualities, showing that they correspond to combinations of T-dualities and Melvin twists. Upon uplift to one dimension higher, these dualities allow us to "untwist" general black holes to AdS 3 times a sphere.

Cveti?, Mirjam; Guica, Monica; Saleem, Zain H.

2013-09-01

465

Dancing with Black Holes  

NASA Astrophysics Data System (ADS)

We describe efforts over the last six years to implement regularization methods suitable for studying one or more interacting black holes by direct N-body simulations. Three different methods have been adapted to large-N systems: (i) Time-Transformed Leapfrog, (ii) Wheel-Spoke, and (iii) Algorithmic Regularization. These methods have been tried out with some success on GRAPE-type computers. Special emphasis has also been devoted to including post-Newtonian terms, with application to moderately massive black holes in stellar clusters. Some examples of simulations leading to coalescence by gravitational radiation will be presented to illustrate the practical usefulness of such methods.

Aarseth, S. J.

2008-05-01

466

Degradation mechanism of azo dye C. I. reactive red 2 by iron powder reduction and photooxidation in aqueous solutions  

Microsoft Academic Search

We have made a comparison of the UV–VIS spectra of three azo dyes, C. I. reactive red 2, orange II and C. I. reactive black 8, in aqueous solutions during treatment with iron powder reduction and photooxidation. From this, we propose their mechanisms for reduction–photooxidation. GC\\/MS analyses of the degradation products of the dye C. I. reactive red 2 demonstrated

Wu Feng; Deng Nansheng; Hua Helin

2000-01-01

467

47 CFR 76.110 - Substitutions.  

Code of Federal Regulations, 2012 CFR

...Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.110 Substitutions. Whenever, pursuant...such community unit may, consistent with these rules and the sports blackout rules at § 76.111, substitute a program from...

2012-10-01

468

47 CFR 76.110 - Substitutions.  

Code of Federal Regulations, 2011 CFR

...Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.110 Substitutions. Whenever, pursuant...such community unit may, consistent with these rules and the sports blackout rules at § 76.111, substitute a program from...

2011-10-01

469

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

470

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

471

Mining coal on Black Mesa  

SciTech Connect

Black Mesa is a remote highland in northeastern Arizona. Peabody Coal Company began surface mining operations on Black Mesa in 1970, leasing 64,868 acres from the Navajo and Hopi tribes. Approximately 12 million tons of coal are mined annually. The paper presented discussed Peabody's mining operation on Black Mesa. Topics detailed include transportation of the coal via the Black Mesa pipeline, dewatering of the slurry, water supply, and Peabody's cross-cultural training program. (JMT)

Grow, G.D.

1981-01-01

472

Quarterly Black Review of Books  

NSDL National Science Digital Library

The Quarterly Black Review of Books is a site that reviews the latest in Black fiction, non-fiction, poetry, and children's books. It also includes a feature section, as well as a guide to Black classics by author, a listing of works of great Black writers that include W.E.B. DuBois, Langston Hughes, Maya Angelou, and Alice Walker, among others. http://www.qbr.com

473

The Thermodynamics of Black Holes  

Microsoft Academic Search

We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics,\\u000a Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given\\u000a of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.

Robert M. Wald

474

Aluminothermic powder boriding of steel  

NASA Astrophysics Data System (ADS)

Subject of thermodynamical analysis are the probable boron transport reactions, boron precipitation and boride forming in the reaction space with the use of aluminothermic boriding mixtures and activators such as NaF, NH 4F, Na 2O·4BF 3 and (NH 4) 2·4BF 3. Aluminothermic boriding of carbon and alloyed steels have been carried out in a powder boriding mixture containing B 2O 3—20%, Al—7%, Al 2O 3—72.5%, and (NH 4) 2O·4BF 3—0.5% at a temperature of 1160 K and within a 6 h period. The thickness and the microhardness of the boride layers have been measured and a layer-by-layer chemical spectrum analysis has been made. The proposed structure of an aluminothermic mixture is determined to be suitable for boriding of low-carbon and low-alloyed steels. The boride layers obtained are distinguished for considerable thickness and high microhardness.

Uzunov, Nikolay; Ivanov, Radoslav

2004-03-01

475

Continuous production of titanium powder  

SciTech Connect

Although incremental improvements have been made to the Kroll process since its inception in 1948, the process in use today remains essentially the same batch process developed by Dr. Kroll and perfected by the U.S. Bureau of Mines. In this process, titanium tetrachloride (TiCl4) is reduced by magnesium to produce titanium metal. There are two major limitations to the Kroll process: (1) it is a batch process; and (2) the reduction of TiCl4 proceeds so rapidly that the sponge formed is an interlocking dendritic mass with inclusions of magnesium, magnesium salts and titanium subchloride that must undergo several purification steps before the metal is suitable for use. The Albany Research Center (ARC), formerly the U.S. Bureau of Mines, has investigated a new, continuous titanium metal production process in which a titanium powder is produced in a bath of molten salt. In this process, the rate of the reduction reaction was slowed and controlled by diluting the reactants with molten chloride salts. The diluted reactant streams were combined in a continuous stirred tank reactor, operated much like a crystallizer. New titanium metal forms on the already present small Ti particles. When the Ti particles become too large to remain suspended in solution, they fall to the bottom of the reactor and are removed. Initial experiments show promise but problems remain in obtaining the required purity and uniform particle size.

Gerdemann, Stephen J.; Oden, Laurence L.; White, Jack C.

1997-01-01

476

Assessment of asbestos insulation substitutes  

SciTech Connect

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

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

1990-03-01

477

Black Education: Myths and Tragedies.  

ERIC Educational Resources Information Center

|The contents of this book are organized in three parts. Part one, "Some personal experiences," includes four chapters dealing with the author's own education: in a segregated school in the South, in Northern ghetto schools, in black and white universities, and his continuing education as a teacher in black and white colleges. Part two, "Black…

Sowell, Thomas

478

Backreaction in Acoustic Black Holes  

NASA Astrophysics Data System (ADS)

The backreaction equations for the linearized quantum fluctuations in an acoustic black hole are given. The solution near the horizon, obtained within a dimensional reduction, indicates that acoustic black holes, unlike Schwarzschild ones, get cooler as they radiate phonons. They show remarkable analogies with near-extremal Reissner-Nordström black holes.

Balbinot, Roberto; Fagnocchi, Serena; Fabbri, Alessandro; Procopio, Giovanni P.

2005-04-01

479

Trends in Black Student Involvement.  

ERIC Educational Resources Information Center

|Examines trends in Black student involvement within traditional campus organizations at predominantly White campuses. Addresses the current state of the cocurricular experience for members of Black Greek-letter organizations as well as Black non-Greeks. Poses suggestions for practitioners to employ in order to increase pluralism within…

Sutton, E. Michael; Kimbrough, Walter M.

2001-01-01

480

"Black" Shows for White Viewers  

ERIC Educational Resources Information Center

|Argues that, in order to improve the portrayal of blacks on network TV, first, black people are going to have to look with more penetrating vision at the image that enters our living rooms and our minds; and, second, enlightened blacks are going to have to speak up to the people who hold the power. (Author/JM)|

Collier, Eugenia

1974-01-01

481

Black Politics and Public Policy  

Microsoft Academic Search

This selective annotated guide highlights some of the key, but relatively unknown sources of information on Black political involvement and Black public policy concerns in contemporary America. The guide emphasizes current works - particularly directories, almanacs, and government reports- that provide statistical data on the political and socioeconomic status of American Blacks. It notes major contemporary book-length studies of public

Auriel Pilgrim

1988-01-01

482

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

483

A Black Hole emerged Universe  

Microsoft Academic Search

A simple model of a universe is presented composed of black holes and black branes. It uses the most simplest approximations and models of General Relativity and Quantum Dynamics to offer an idea of an unification and gives a possible answer to the quantization and entropy of Black Holes. It proposes a mass spectra for elementary particles and gives a

H. Genreith

1999-01-01

484

Black-spot poison ivy.  

PubMed

In black-spot poison ivy dermatitis, a black lacquerlike substance forms on the skin when poison ivy resin is exposed to air. Although the Toxicodendron group of plants is estimated to be the most common cause of allergic contact dermatitis in the United States, black-spot poison ivy dermatitis is relatively rare. PMID:18346397

Schram, Sarah E; Willey, Andrea; Lee, Peter K; Bohjanen, Kimberly A; Warshaw, Erin M

485

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.

486

Synthesis of nanocrystalline tungsten carbide (WC) powder  

NASA Astrophysics Data System (ADS)

Nanocrystalline tungsten carbide (WC) has been obtained from bulk WO3 by in situ reduction and carbonization reactions at low temperature (~ 600 °C) by taking Mg as reductant and acetone C3H6O as carbon source. It was aimed to elucidate carburization behavior of WO3 powder and to establish optimal conditions for the synthesis of nanocrystalline WC. The role of reaction time on the synthesis of WC has been investigated and discussed. The synthesized powders were characterized by X-ray powder diffraction, differential thermal analyzer (DTA), thermo gravimetric analysis (TGA).

Singla, Gourav; Singh, K.; Pandey, O. P.

2013-06-01

487

Electrical Resistivity of Metal Powder Aggregates  

NASA Astrophysics Data System (ADS)

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 system consisting of deforming spheres in a simple cubic packing, which is much easier to examine. The proposed equation was experimentally verified from measurements of the electrical resistivity for aluminum, bronze, iron, and nickel powders under pressure. The consistency between theoretical predictions and experimental results was reasonably good in all cases.

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

2007-12-01

488

Preparation and Reactions of Substituted Ethenesulfenate Anions  

Microsoft Academic Search

Trans-alkyl and gem-silyl substituted ethenesulfenate anions result from the reaction of hexamethyldisilazide bases with anti-alkyl and anti-silyl substituted thiirane-S-oxides, respectively, via a stereoselective deprotonation process. The sulfenates can be captured at sulfur with certain alkyl halides or they can be converted to a series of substituted ethenesulfenic acid amides.

Adrian L. Schwan; Mitchell D. Refvik

1994-01-01

489

Substitutes for School Nurses in Illinois  

ERIC Educational Resources Information Center

|The purpose of this descriptive study was to explore utilization of nurse substitutes in the school setting in Illinois. The literature described personnel who staff the school health office in the absence of the school nurse and the barriers to obtaining nurse substitutes. There were no empirical studies conducted on school nurse substitutes in…

Vollinger, Linda Jeno; Bergren, Martha Dewey; Belmonte-Mann, Frances

2011-01-01

490

Generic Substitution of Narrow Therapeutic Index Drugs  

Microsoft Academic Search

Controversy regarding generic substitution of narrow therapeutic index drugs, especially antiepileptic drugs, has become a big debate lately. Some states are considering passing laws that will restrict the generic substitution of these narrow therapeutic index drugs. In fact, some states have already modified their laws to limit switching and generic substitution of these medications, requiring patient and prescriber consent before

Mays Putrus

491

Glass powder blended cement hydration modelling  

NASA Astrophysics Data System (ADS)

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

Saeed, Huda

492

A Different Reason Why Black Holes are Black  

NASA Astrophysics Data System (ADS)

Although it is true that black holes appear to be black on the outside due to the fact that the escape velocity from the event horizon is even higher than that of light, black holes may be black on the inside as well. A recent paper by Zach Adams (2009) presents a new model which provides evidence of gravitons actually being a result of a fusion of 2 photons, which manifests in 4-D space. In fact, the duality between gravitons and photons has been suggested in earlier works as well. Falling Photon Experiment shows that as photons approach a massive body, their energies increase, and their wavelengths decrease. Photon-graviton conversions occur when the wavelengths of photons decrease to Planck's length. As a result, the photons approaching the event horizon of a black hole may gain energy enough for photon pairs to fuse and become gravitons. Therefore, as we will discuss in this work, there exists a probability that photons cannot survive within the event horizon of a black hole. It is true that nothing can escape a black hole, which is the reason why it looks black on the outside, but also the possibility that photons may not be able to survive on a black hole means that black holes may be black on the inside as well.

Farghal, Noha S.

2009-11-01

493

Merging black holes  

Microsoft Academic Search

Black-hole mergers take place in regions of very strong and dynamical gravitational fields, and are among the strongest sources of gravitational radiation. Probing these mergers requires solving the full set of Einstein's equations of general relativity numerically. For more than 40 years, progress towards this goal has been very slow, as numerical relativists encountered a host of difficult problems. Recently,

Joan Centrella; John Baker; Bernard Kelly; James van Meter

2011-01-01

494

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.

495

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

496

[Thematic Issue: Black Theatre.  

ERIC Educational Resources Information Center

|"Nummo" refers to "the word" or "word force." The aim of this publication is to provide a common forum for the utilization of the word force in exploring the opinions and creations of black community, educational, and professional theatre artists and scholars. This issue includes a play called "The Twilight Dinner" by Lennox Brown; a review of…

Morrison, Carl F., Jr., Ed.

497

The Black Faculty Gap.  

ERIC Educational Resources Information Center

Reviews Cole and Barber's "Increasing Faculty Diversity: The Occupational Choices of High-Achieving Minority Students," which has aroused controversy because its findings bear directly on the University of Michigan's affirmative action cases. Cole and Barber surveyed minority and white students in Ivy League, elite, and historically black…

Glazer, Nathan

2003-01-01

498

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.

499

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

500

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