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1

30 CFR 57.6901 - Black powder.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

2

30 CFR 56.6901 - Black powder.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

3

30 CFR 57.6901 - Black powder.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

4

30 CFR 57.6901 - 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 be— (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 56.6901 - Black powder.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

6

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 be— (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2013-07-01

7

30 CFR 56.6901 - Black powder.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

8

30 CFR 57.6901 - Black powder.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

9

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 be— (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2010-07-01

10

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 be— (1) Nonsparking...of this section. (c) Black powder shall be transferred...damaged explosives. (f) Holes shall not be reloaded for...

2010-07-01

11

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

Microsoft Academic Search

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

D. C. Cook; T. H. Kim

1997-01-01

12

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2010 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...

2010-10-01

13

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2014 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...

2014-10-01

14

49 CFR 173.170 - Black powder for small arms.  

Code of Federal Regulations, 2013 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...

2013-10-01

15

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

16

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

17

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

18

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

PubMed Central

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

Shin, Myung-Gon; Lee, Gyu-Hee

2013-01-01

19

Accurate characterization of pure silicon-substituted hydroxyapatite powders1 synthesized by a new precipitation route2  

E-print Network

material in the field of bioactive bone substitutes and bone tissue engineering. It is now well-51 in bone repair. The SiHA58 structure corresponds to the substitution of phosphate ions (PO4 31 Accurate characterization of pure silicon-substituted hydroxyapatite powders1 synthesized

20

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

Microsoft Academic Search

Nickel was substituted in various proportions for cobalt in a series of five hot-isostatically-pressed powder metallurgy alloys based on the UDIMET 700 composition. These alloys were given 5-step heat treatments appropriate for use in turbine engine disks. The resultant microstructures displayed three distinct sizes of gamma' particles in a gamma matrix. The higher cobalt-content alloys contained larger amounts of the

Fredric H. Harf

1985-01-01

21

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

Microsoft Academic Search

Nickel was substituted in various proportions for cobalt in a series of five hot-isostatically-pressed powder metallurgy alloys\\u000a based on the UDIMET 700 composition. These alloys were given 5-step heat treatments appropriate for use in turbine engine\\u000a disks. The resultant microstructures displayed three distinct sizes of ?? particles in a ? matrix. The higher cobalt-content\\u000a alloys contained larger amounts of the

Fredric H. Harf

1985-01-01

22

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

PubMed

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

Hausnerova, Berenika; Kuritka, Ivo; Bleyan, Davit

2014-01-01

23

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

24

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

Microsoft Academic Search

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

I. Wawer; M. Wolniak; K. Paradowska

2006-01-01

25

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

26

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

27

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

28

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

29

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

30

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

31

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

Code of Federal Regulations, 2013 CFR

. (1) The chemical substance identified generically as carbon black, (4-methylphenyl)-modified, substituted (PMN P-07-523) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new uses...

2013-07-01

32

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

Code of Federal Regulations, 2011 CFR

. (1) The chemical substance identified generically as carbon black, (3-methylphenyl)-modified, substituted (PMN P-07-522) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new uses...

2011-07-01

33

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

Code of Federal Regulations, 2011 CFR

. (1) The chemical substance identified generically as carbon black, (4-methylphenyl)-modified, substituted (PMN P-07-523) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new uses...

2011-07-01

34

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

Code of Federal Regulations, 2010 CFR

. (1) The chemical substance identified generically as carbon black, (4-methylphenyl)-modified, substituted (PMN P-07-523) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new uses...

2010-07-01

35

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

Code of Federal Regulations, 2012 CFR

. (1) The chemical substance identified generically as carbon black, (3-methylphenyl)-modified, substituted (PMN P-07-522) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new uses...

2012-07-01

36

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

Code of Federal Regulations, 2012 CFR

. (1) The chemical substance identified generically as carbon black, (4-methylphenyl)-modified, substituted (PMN P-07-523) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this section. (2) The significant new uses...

2012-07-01

37

Evaluating Renewable Cornstarch/biochar Fillers as Potential Substitutes for Carbon Black in SBR Composites  

Technology Transfer Automated Retrieval System (TEKTRAN)

The continually growing demand for fossil fuels coupled with the potential risk of relying on foreign sources for these fuels strengthens the need to find renewable substitutes for petroleum products. Carbon black is a petroleum product that dominates the rubber composite filler market. Agricultur...

38

Preparation of yellowish-red Al-substituted ?-Fe2O3 powders and their thermostability in color.  

PubMed

Inspired by the traditional Japanese pigment Fukiya bengala, nanocomposite materials were synthesized using a polymer complex method, comprising Al-substituted ?-Fe2O3 (hematite) particles with diameters ranging from 40 to 100 nm and ultrafine Fe-substituted ?-Al2O3 (corundum) particles smaller than 10 nm in diameter. The obtained powders exhibited a vivid yellowish-red color and high thermostability, making them attractive as potential overglaze enamels on porcelain. Quantitative color measurements revealed that, when heated to 700, 800, and 900 °C, samples displayed high lightness (L*) and color-opponent dimensions (a* and b*) at 10 mol % Al. For the same particle size samples, L*, a*, and b* values increased with the Al molar ratio, revealing that Al substitution in the hematite structure intrinsically enhances lightness and chroma in hematite color. These samples mostly retained their color upon reheating at 900 °C, indicating their high thermostability. This thermostability should originate from the Al substitution-induced enhancement in lightness and chroma in hematite color, which should counter color fading caused by particle growth. These composite materials are expected to find application in the porcelain industry, cosmetics, and nanotechnology. PMID:25313688

Hashimoto, Hideki; Nakanishi, Makoto; Asaoka, Hiroshi; Maeda, Tomoaki; Kusano, Yoshihiro; Fujii, Tatsuo; Takada, Jun

2014-11-26

39

Magnetic comparison of BaCa and BaSr substituted hexaferrite powders  

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

40

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

41

Crystal Structure of Nonstoichiometric Copper-Substituted La(Ni 1- zCu z) x Compounds Studied by Neutron and Synchrotron Anomalous Powder Diffraction  

NASA Astrophysics Data System (ADS)

The structural properties of the potential battery electrode materials LaNi4Cu, LaNi4.4Cu, LaNi5Cu, and LaNi4.5Cu1.5 have been investigated by neutron and anomalous synchrotron powder diffraction. The nonstoichiometry of such ABx (5?x?6) compounds has been described in a structure derived from the hexagonal CaCu5-type structure by replacement of the A atoms by dumbbells of B atoms. In these copper-substituted compounds, Cu can occupy any of the four available nickel sites. From a joint refinement procedure using both neutron and synchrotron data, the copper-to-nickel ratio at each B site has been determined. This shows that substitution is not random and that copper occupies some crystallographic sites preferentially. The results are discussed and compared to other substituted AB5 systems.

Latroche, M.; Joubert, J.-M.; Percheron-Guégan, A.; Notten, P. H. L.

1999-09-01

42

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

PubMed

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

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

2009-05-01

43

Carbon Powders Prepared by Ultrasonic Spray Pyrolysis of Substituted Alkali Benzoates Sara E. Skrabalak and Kenneth S. Suslick*  

E-print Network

for separations, selective absorbents, lightweight composite components, and catalyst supports.5-10 The synthetic.22-24 There are numerous examples of inorganic materials (e.g., metal oxides and sulfides) being produced as fine powders from USP of metal salt containing solutions (e.g., typically, metal nitrates

Suslick, Kenneth S.

44

Magnetic properties of Cr3+ substituted BaFe12O19 powders grown by a sol-gel method  

Microsoft Academic Search

Cr3+ substituted Ba-hexaferrite was fabricated by a sol-gel method. The crystallographic and magnetic properties of BaFe12-xCrxO19 (0⩽x⩽7) were investigated XRD, Rutherford backscattering spectrometry, vibrating sample magnetometry and Mossbauer spectroscopy. The crystal structure was found to be magnetoplumbite, typical of M-type hexagonal ferrite. By substituting Fe3+ in BaFe12O19 by Cr 3+, we have been able to attribute the Mossbauer parameters to

Chul Sung Kim; Sung Yong An; Ji Hee Son; Jae-Gwang Lee; Hang Nam Oak

1999-01-01

45

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

46

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

47

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

Microsoft Academic Search

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

Mohsen Bahmani-Oskooee; Altin Tanku

2006-01-01

48

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

PubMed

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

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

2009-08-30

49

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

50

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

51

Anti-inflammatory effects of freeze-dried black raspberry powder in ulcerative colitis  

PubMed Central

Ulcerative colitis (UC) is a chronic inflammatory disease of the colonic mucosa that can dramatically increase the risk of colon cancers. In the present study, we evaluated the effects of a dietary intervention of freeze-dried black raspberries (BRB), a natural food product with antioxidant and anti-inflammatory bioactivities, on disease severity in an experimental mouse model of UC using 3% dextran sodium sulfate (DSS). C57BL/6J mice were fed either a control diet or a diet containing BRB (5 or 10%) for 7–14 days and then the extent of colonic injury was assessed. Dietary BRB markedly reduced DSS-induced acute injury to the colonic epithelium. This protection included better maintenance of body mass and reductions in colonic shortening and ulceration. BRB treatment, however, did not affect the levels of either plasma nitric oxide or colon malondialdehyde, biomarkers of oxidative stress that are otherwise increased by DSS-induced colonic injury. BRB treatment for up to 7 days suppressed tissue levels of several key pro-inflammatory cytokines, including tumor necrosis factor ? and interleukin 1?. Further examination of the inflammatory response by western blot analysis revealed that 7 day BRB treatment reduced the levels of phospho-I?B? within the colonic tissue. Colonic cyclooxygenase 2 levels were also dramatically suppressed by BRB treatment, with a concomitant decrease in the plasma prostaglandin E2 (276 versus 34 ng/ml). These findings demonstrate a potent anti-inflammatory effect of BRB during DSS-induced colonic injury, supporting its possible therapeutic or preventive role in the pathogenesis of UC and related neoplastic events. PMID:21098643

Montrose, David C.; Horelik, Nicole A.; Madigan, James P.; Stoner, Gary D.; Wang, Li-Shu; Bruno, Richard S.; Park, Hea Jin; Giardina, Charles; Rosenberg, Daniel W.

2011-01-01

52

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

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

53

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

54

Simple, heart-smart substitutions  

MedlinePLUS

... fillet with skin cut in center ½ tsp garlic powder ½ tsp black pepper As needed, fat- ... skin side down, on prepared sheet. Sprinkle with garlic powder and pepper. Spread with the sauce. Bake ...

55

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

56

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon black, 4-[[2-(Sulfooxy...Substances § 721.10075 Carbon black, 4-[[2-(Sulfooxy...substance identified generically as carbon black, 4-[[2-(Sulfooxy...section. [72 FR 53484, Sept. 19,...

2010-07-01

57

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

58

Outdoor Weathering Evaluation of Carbon-Black-Filled, Biodegradable Copolyester as Substitute for Traditionally Used, Carbon-Black-Filled, Nonbiodegradable, High-Density Polyethylene Mulch Films  

Microsoft Academic Search

Carbon-black-filled, biodegradable, copolyester mulch film (Eastar®, or EA, Tennessee Eastman, Kingsport, TN) and commercial carbon-black-filled, high-density polyethylene (HDPE) mulch film were exposed for 12 weeks to commercial vegetable crop growing conditions by being placed directly on irrigated soil in the field of the University of Tennessee Alcoa Highway State Agriculture Experiment Station (Knoxville, TN) and by being placed on a

R. S. Tocchetto; R. S. Benson; M. Dever

2001-01-01

59

Fatal contact shot to the chest caused by the gas jet from a muzzle-loading pistol discharging only black powder and no bullet: case study and experimental simulation of the wounding effect.  

PubMed

In modern medico-legal literature, only a small number of publications deal with fatal injuries from black powder guns. Most of them focus on the morphological features such as intense soot soiling, blast tattooing and burn effects in close-range shots or describe the wound ballistics of spherical lead bullets. Another kind of "unusual" and potentially lethal weapons are handguns destined for firing only blank cartridges such as starter and alarm pistols. The dangerousness of these guns is restricted to very close and contact range shots and results from the gas jet produced by the deflagration of the propellant. The present paper reports on a suicide committed with a muzzle-loading percussion pistol cal. 45. An unusually large stellate entrance wound was located in the precordial region, accompanied by an imprint mark from the ramrod and a faint greenish discoloration (apparently due to the formation of sulfhemoglobin). Autopsy revealed an oversized powder cavity, multiple fractures of the anterior thoracic wall as well as ruptures of the heart, the aorta, the left hepatic lobe and the diaphragm. In total, the zone of mechanical destruction had a diameter of approx. 15 cm. As there was no exit wound and no bullet lodged in the body, the injury was caused exclusively by the inrushing combustion gases of the propellant (black powder) comparable with the gas jet of a blank cartridge gun. In contact shots to ballistic gelatine using the suicide's pistol loaded with black powder but no projectile, the formation of a nearly spherical cavity could be demonstrated by means of a high-speed camera. The extent of the temporary cavity after firing with 5 g of black powder roughly corresponded to the zone of destruction found in the suicide's body. PMID:25119685

Große Perdekamp, Markus; Glardon, Matthieu; Kneubuehl, Beat P; Bielefeld, Lena; Nadjem, Hadi; Pollak, Stefan; Pircher, Rebecca

2015-01-01

60

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

PubMed Central

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

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

2014-01-01

61

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

PubMed Central

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

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

2014-01-01

62

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

63

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.

American Chemical Society

2000-01-01

64

Magnetic properties of substituted barium ferrite powders  

SciTech Connect

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

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

1994-03-01

65

Skin Substitutes  

PubMed Central

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

Howe, Nicole; Cohen, George

2014-01-01

66

Influence of moisture content on inactivation of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in powdered red and black pepper spices by radio-frequency heating.  

PubMed

The influence of moisture content during radio-frequency (RF) heating on heating rate, dielectric properties, and inactivation of foodborne pathogens was investigated. The effect of RF heating on the quality of powdered red and black pepper spices with different moisture ranges was also investigated. Red pepper (12.6%, 15.2%, 19.1%, and 23.3% dry basis, db) and black pepper (10.1%, 17.2%, 23.7%, and 30.5% db) inoculated with Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium were treated in a RF heating system with 27.12 MHz. The heating rate of the sample was dependent on moisture content up to 19.1% (db) of red pepper and 17.2% (db) of black pepper, but there was a significant decrease in the heating rate when the moisture content was increased beyond these levels. The dielectric properties of both samples increased with a rise in moisture content. As the moisture content increased, treatment time required to reduce E. coli O157:H7 and S. Typhimurium by more than 7 log CFU/g (below the detection limit, 1 log CFU/g) decreased and then increased again without affecting product quality when the moisture content exceeded a level corresponding to the peak heating rate. RF treatment significantly (P<0.05) reduced moisture content of both spices. These results suggest that RF heating can be effectively used to not only control pathogens but also reduce moisture levels in spices and that the effect of inactivation is dependent on moisture content. PMID:24555992

Jeong, Seul-Gi; Kang, Dong-Hyun

2014-04-17

67

Energetic powder  

DOEpatents

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

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

2003-12-23

68

Exploring Baking Powder  

NSDL National Science Digital Library

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

Kessler, James H.; Galvan, Patricia M.

2007-01-01

69

Powder treatment process  

DOEpatents

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

Weyand, John D. (Greensburg, PA)

1988-01-01

70

Powder treatment process  

DOEpatents

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

Weyand, J.D.

1988-02-09

71

Powder Diffraction in Zeolite Science  

NASA Astrophysics Data System (ADS)

This tutorial discusses the fundamental principles of X-ray diffraction and its applications in zeolite science. The early sections review the physics of diffraction, crystal symmetry, and reciprocal space. We discuss how the intensity of diffracted radiation is affected both by geometric effects involving detection (the Lorentz-polarization factor) and by the arrangement of atoms within the crystal (the structure factor). The differences between powder diffraction and single-crystal diffraction are then described, and differences between X-ray and neutron diffraction are also discussed. Later sections describe the effects of symmetry, lattice substitution, crystallite size, residual strain, preferred orientation, and X-ray absorption. Special emphasis is placed on the proper application of the Scherrer analysis in reporting crystalize size. The principles of structure solution from direct methods and Patterson methods are then introduced, and a description of Rietveld analysis is given. Finally the effects of stacking disorder on a powder diffraction pattern are presented.

Burton, Allen W.

72

Pinwheel patterns and powder diffraction  

E-print Network

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, with emphasis on statistical properties that are helpful to understand and compare the diffraction images. We concentrate on properties that are accessible via an alternative substitution rule for the pinwheel tiling, based on two different prototiles. Due to striking similarities, we compare our results with the toy model for the powder diffraction of the square lattice.

Michael Baake; Dirk Frettlöh; Uwe Grimm

2006-10-06

73

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

74

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

75

Substitute Teachers  

NSDL National Science Digital Library

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

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

2003-01-01

76

Resin-Powder Dispenser  

NASA Technical Reports Server (NTRS)

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

Standfield, Clarence E.

1994-01-01

77

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

SciTech Connect

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

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

2013-01-15

78

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

79

Injectability of brushite-forming Mg-substituted and Sr-substituted ?-TCP bone cements  

Microsoft Academic Search

The influence of magnesium- and strontium-substitutions on injectability and mechanical performance of brushite-forming ?-TCP\\u000a cements has been evaluated in the present work. The effects of Mg- and Sr-substitutions on crystalline phase composition and\\u000a lattice parameters were determined through quantitative X-ray phase analysis and structural Rietveld refinement of the starting\\u000a calcium phosphate powders and of the hardened cements. A noticeable dependence

S. Pina; P. M. C. Torres; J. M. F. Ferreira

2010-01-01

80

Composite powder particles  

NASA Technical Reports Server (NTRS)

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

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

2009-01-01

81

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

82

Gelcasting superalloy powders  

Microsoft Academic Search

Gelcasting is a process for forming inorganic powders into complex shapes. It was originally developed for ceramic powders. A slurry of powder and a monomer solution is poured in to mold and polymerized in-situ to form gelled parts. Typically, only 2-4 wt % Polymer is used. The process has both aqueous and nonaqueous versions. Gelcasting is a generic process and

Janney

1995-01-01

83

Dustiness of Fine and Nanoscale Powders  

PubMed Central

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

Evans, Douglas E.; Baron, Paul A.

2013-01-01

84

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

85

Multiple feed powder splitter  

DOEpatents

A device for providing uniform powder flow to the nozzles when creating solid structures using a solid fabrication system such as the directed light fabrication (DLF) process. In the DLF process, gas entrained powders are passed through the focal point of a moving high-power laser light which fuses the particles in the powder to a surface being built up in layers. The invention is a device providing uniform flow of gas entrained powders to the nozzles of the DLF system. The device comprises a series of modular splitters which are slidably interconnected and contain an integral flow control mechanism. The device can take the gas entrained powder from between one to four hoppers and split the flow into eight tubular lines which feed the powder delivery nozzles of the DLF system.

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

2001-01-01

86

Multiple feed powder splitter  

DOEpatents

A device for providing uniform powder flow to the nozzles when creating solid structures using a solid fabrication system such as the directed light fabrication (DLF) process. In the DLF process, gas entrained powders are passed through the focal point of a moving high-power laser light which fuses the particles in the powder to a surface being built up in layers. The invention is a device providing uniform flow of gas entrained powders to the nozzles of the DLF system. The device comprises a series of modular splitters which are slidably interconnected and contain an integral flow control mechanism. The device can take the gas entrained powder from between one to four hoppers and split the flow into eight tubular lines which feed the powder delivery nozzles of the DLF system.

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

2002-01-01

87

Intrinsic Coercivity of Substituted BaFe12O19  

Microsoft Academic Search

Intrinsic coercive force measurements were made on BaFe12O19 in which certain amounts of Fe were substituted by In, Cr, Al, Ga, ZnGe, ZnV, ZnNb or ZnTa. The specimens were prepared by the ordinary powder metallurgy method. X-ray diffraction of the specimens indicated only the presence of the magnetoplumbite phase within the experimental substitution range. A large increase in coercive force

Koichi Haneda; Hiroshi Kojima

1973-01-01

88

PRESSURELESS SINTERED BERYLLIUM POWDER  

Microsoft Academic Search

A new process, termed pressureless sintering, has been established for ; the production of beryllium shapes (solid or hollow) to near theoretical density. ; It consists simply of the vacuum sintering at 1,200 deg C of loose powder of ; critical particle size distribution, without the application of pressure. ; Notable advantages are claimed over conventional powder production and ;

T. R. Barrett; G. C. Ellis; R. A. Knight

1959-01-01

89

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

90

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

91

Compaction of Titanium Powders  

SciTech Connect

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

Gerdemann, Stephen,J; Jablonski, Paul, J

2011-05-01

92

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

93

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

94

POWDER COAT APPLICATIONS  

EPA Science Inventory

The report discusses an investigation of critical factors that affect the use of powder coatings on the environment, cost, quality, and production. The investigation involved a small business representative working with the National Defense Center for Environmental Excellence (ND...

95

Mystery Powder Investigation  

NSDL National Science Digital Library

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

Rachel HallettNjuguna

2012-07-27

96

Gelcasting superalloy powders  

SciTech Connect

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

Janney, M.A.

1995-12-31

97

Hafnium powder production processes  

NASA Astrophysics Data System (ADS)

The conditions for the production of hafnium nanopowders via magnesium-thermic reduction of chlorides and the effect of these conditions on the phase composition and dispersion of the powders are studied analytical chemistry, X-ray diffractin, and electron microscopy. The results of phase and structural analysis of the powders, the results of microscopic studies, the measured specific surface, and the data of atomicemission analysis are presented.

Dzidziguri, E. L.; Salangina, E. A.; Sidorova, E. N.

2010-09-01

98

Shear consolidation of powders  

NASA Astrophysics Data System (ADS)

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

Hanna, James A.

99

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

100

Synthesis of high surface area ZnO powder by continuous precipitation  

SciTech Connect

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

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

2012-05-15

101

Method for classifying ceramic powder  

NASA Technical Reports Server (NTRS)

Under the invented method, powder A of particles of less than 10 microns, and carrier powder B, whose average particle diameter is more than five times that of powder A, are premixed so that the powder is less than 40 wt.% of the total mixture, before classifying.

Takabe, K.

1983-01-01

102

Microwave-hydrothermal synthesis of Al-substituted tobermorite from zeolites  

Microsoft Academic Search

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

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

2002-01-01

103

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

SciTech Connect

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

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

2012-06-15

104

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

105

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

106

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. PMID:22110809

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

107

Whole powder pattern modelling.  

PubMed

A new approach for the modelling of diffraction patterns without using analytical profile functions is described and tested on ball milled f.c.c. Ni powder samples. The proposed whole powder pattern modelling (WPPM) procedure allows a one-step refinement of microstructure parameters by a direct modelling of the experimental pattern. Lattice parameter and defect content, expressed as dislocation density, outer cut-off radius, contrast factor, twin and deformation fault probabilities), can be refined together with the parameters (mean and variance) of a grain-size distribution. Different models for lattice distortions and domain size and shape can be tested to simulate or model diffraction data for systems as different as plastically deformed metals or finely dispersed crystalline powders. TEM pictures support the conclusions obtained by WPPM and confirm the validity of the proposed procedure. PMID:11832590

Scardi, P; Leoni, M

2002-03-01

108

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

109

Iowa Powder Atomization Technologies  

SciTech Connect

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

None

2012-01-01

110

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

111

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

112

Sustainability and substitutability.  

PubMed

Developing a quantitative science of sustainability requires bridging mathematical concepts from fields contributing to sustainability science. The concept of substitutability is central to sustainability but is defined differently by different fields. Specifically, economics tends to define substitutability as a marginal concept while fields such as ecology tend to focus on limiting behaviors. We explain how to reconcile these different views. We develop a model where investments can be made in knowledge to increase the elasticity of substitution. We explore the set of sustainable and optimal trajectories for natural capital extraction and built and knowledge capital accumulation. Investments in substitutability through knowledge stock accumulation affect the value of natural capital. Results suggest that investing in the knowledge stock, which can enhance substitutability, is critical to desirable sustainable outcomes. This result is robust even when natural capital is not managed optimally. This leads us to conclude that investments in the knowledge stock are of first order importance for sustainability. PMID:24789570

Fenichel, Eli P; Zhao, Jinhua

2015-02-01

113

Synthesis of 2-(substituted anilino) 4-(substituted phenyl)thiazoles.  

PubMed

2-(Substituted anilino) 4-(substituted phenyl)thiazoles were synthesized by condensing 2-haloketones with substituted thioureas. The biological screening of some compounds indicated hypoglycemic and hyperglycemic activity. PMID:641782

Thakar, K A; Goswami, D D; Choudhari, S R

1978-04-01

114

Method for synthesizing powder materials  

DOEpatents

A method for synthesizing ultrafine powder materials, for example, ceramic and metal powders, comprises admitting gaseous reactants from which the powder material is to be formed into a vacuum reaction chamber maintained at a pressure less than atmospheric and at a temperature less than about 400/degree/K (127/degree/C). The gaseous reactants are directed through a glow discharge provided in the vacuum reaction chamber to form the ultrafine powder material. 1 fig.

Buss, R.J.; Ho, P.

1988-01-21

115

Rationing, Queues, and Black Markets  

Microsoft Academic Search

Several types of rationing and queue mechanisms are compared in a framework of general equilibrium type models under gross substitutability and normality assumptions about consumers' Walrasian demand. During transition from rationing and queues to a market system, a group of low income people loses. The transition involves larger losses for this group if black markets prevail under rationing or queues,

Victor. Polterovich

1993-01-01

116

Accuracy in Powder Diffraction IV  

E-print Network

Accuracy in Powder Diffraction IV Program April 22-25, 2013 Photo credit ©2000 Robert Rathe #12;2 3 Accuracy in Powder Diffraction IV Program April 22-25, 2013 Day 1 | 22nd April Time Activity Chair 08 Introduction to program (Madsen, Cline) James Cline Ian Madsen 09:45 - 10:30 Accuracy in Powder Diffraction

Magee, Joseph W.

117

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

118

Sugar substitutes during pregnancy  

PubMed Central

Abstract Question I have a pregnant patient who regularly consumes sugar substitutes and she asked me if continuing their use would affect her pregnancy or child. What should I tell her, and are there certain options that are better for use during pregnancy? Answer Although more research is required to fully determine the effects of in utero exposure to sugar substitutes, the available data do not suggest adverse effects in pregnancy. However, it is recommended that sugar substitutes be consumed in moderate amounts, adhering to the acceptable daily intake standards set by regulatory agencies. PMID:25392440

Pope, Eliza; Koren, Gideon; Bozzo, Pina

2014-01-01

119

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

120

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

121

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

122

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

123

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

124

Sugar Substitutes: Aspartame  

MedlinePLUS

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

125

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

126

Black Saturn  

E-print Network

Using the inverse scattering method we construct an exact stationary asymptotically flat 4+1-dimensional vacuum solution describing Black Saturn: a spherical black hole surrounded by a black ring. Angular momentum keeps the configuration in equilibrium. Black saturn reveals a number of interesting gravitational phenomena: (1) The balanced solution exhibits 2-fold continuous non-uniqueness for fixed mass and angular momentum; (2) Remarkably, the 4+1d Schwarzschild black hole is not unique, since the black ring and black hole of black saturn can counter-rotate to give zero total angular momentum at infinity, while maintaining balance; (3) The system cleanly demonstrates rotational frame-dragging when a black hole with vanishing Komar angular momentum is rotating as the black ring drags the surrounding spacetime. Possible generalizations include multiple rings of saturn as well as doubly spinning black saturn configurations.

Henriette Elvang; Pau Figueras

2007-01-04

127

Black holes  

PubMed Central

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

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

2001-01-01

128

Investigation of Soap Powders  

E-print Network

.42%* HagCOa 71.52%* Total 98T 5 Sopade. Manufactured by James Pyle & Company, Hew York, H. Y. Wt. ya£ Price 5 cents. Analysis• Moisture 26 .23$ HaaHPO* 1 8 . 1 7 * NaaCOa 5 S . 3 2 J Total 99.72% Rub Ho More* Manufactured by Summit City Soap... 98.16$ Gold Dust Washing Powder. Manufactured by N. K. Fairbanks Company. Wt. 3/4 pound Price 5 cents. Analysis. Moisture 14.79$ Soap 35.02$ Na 2C0 a 49.10$ Total 98.91$ Star Naphtha. Manufactured by Proctor & Gamble, Kansas City Wt. 1...

Bragg, G.A.

1913-01-01

129

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

NASA Technical Reports Server (NTRS)

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

Arias, A.

1975-01-01

130

Sintering of powder mixtures and the growth of ferrous powder metallurgy  

Microsoft Academic Search

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

K. S Narasimhan

2001-01-01

131

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

132

Fabrication and performance of silver coated copper powder  

NASA Astrophysics Data System (ADS)

Electroless silver coating on copper powder and its effects on oxidation resistance were investigated by varying the fabrication parameters. Using acetylacetone (C5H8O2) as chelating reagent, silver-coated copper powder was fabricated by displacement reaction method. In the process, acetylacetone forms chelating compound with Cu 2+, which prevent the formation of [Cu (NH3)4]2+. Therefore, Ag + can be reduced continully and deposited on the surface of copper particles. As-coated copper particles were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM) and x-ray energy dispersive spectroscopy (EDS). The oxidation resistance of silver coated copper powder was investigated by gravimetric method. It was found that a fairly continuous silver layer was formed on the surface of copper powder by the electroless type of substitution plating. When the silver content reached 10 wt. %, silver was homogeneously distributed around the copper particles and few free silver particles were detected. The results showed that the silver coated copper powder with the best oxidation resistance was prepared at 40°C and the C5H8O2/AgNO3 molar ratio was 1:1.

Cao, Xiao Guo; Zhang, Hai Yan

2012-08-01

133

Parametric Powder Diffraction  

NASA Astrophysics Data System (ADS)

The rapidity with which powder diffraction data may be collected, not only at neutron and X-ray synchrotron facilities but also in the laboratory, means that the collection of a single diffraction pattern is now the exception rather than the rule. Many experiments involve the collection of hundreds and perhaps many thousands of datasets where a parameter such as temperature or pressure is varied or where time is the variable and life-cycle, synthesis or decomposition processes are monitored or three-dimensional space is scanned and the three-dimensional internal structure of an object is elucidated. In this paper, the origins of parametric diffraction are discussed and the techniques and challenges of parametric powder diffraction analysis are presented. The first parametric measurements were performed around 50 years ago with the development of a modified Guinier camera but it was the automation afforded by neutron diffraction combined with increases in computer speed and memory that established parametric diffraction on a strong footing initially at the ILL, Grenoble in France. The theoretical parameterisation of quantities such as lattice constants and atomic displacement parameters will be discussed and selected examples of parametric diffraction over the past 20 years will be reviewed that highlight the power of the technique.

David, William I. F.; Evans, John S. O.

134

Aryl substitution of pentacenes  

PubMed Central

Summary A series of 11 new pentacene derivatives has been synthesized, with unsymmetrical substitution based on a trialkylsilylethynyl group at the 6-position and various aryl groups appended to the 13-position. The electronic and physical properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of unsymmetrical substitution on the solid-state packing of the pentacene derivatives. The obtained results add to our ability to better predict substitution patterns that might be helpful for designing new semiconductors for use in solid-state devices. PMID:25161729

Waterloo, Andreas R; Sale, Anna-Chiara; Lehnherr, Dan; Hampel, Frank

2014-01-01

135

Photoacoustic Spectroscopy of BiOCl Photocatalyst Powder  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

136

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

137

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

138

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

139

Bone graft substitutes.  

PubMed

Replacement of missing bone stock is a reconstructive challenge to upper extremity surgeons and decision-making with regards to available choices remains difficult. Preference is often given to autograft in the form of cancellous, cortical, or corticocancellous grafts from donor sites. However, the available volume from such donor sites is limited and fraught with potential complications. Advances in surgical management and medical research have produced a wide array of potential substances that can be used for bone graft substitute. Considerations in selecting bone grafts and substitutes include characteristic capabilities, availability, patient morbidity, immunogenicity, potential disease transmission, and cost variability. PMID:23101596

Bhatt, Reena A; Rozental, Tamara D

2012-11-01

140

Linsky, Quine, and Substitutivity  

E-print Network

LINSKYi QUINE, AND SUBSTITUTIVITY Charles Schlee It has been argued by Linsky that the principle of inter-substitutivity salva veritate of co-referential sin­ gular terms in sentences (PS) 1B "just false," that it is such that "no two terms obey... it" ([l ] i 100). What Linsky has criticized is a characterization of PS provided by Quine in "Reference and Modality" ([il], 139). An alter­ native characterization of PS has been employed by Quine in Word and Object ([ill], 1^3). I will argue...

Schlee, Charles

1975-11-01

141

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

142

Combustion synthesis of hexagonal aluminum nitride powders under low nitrogen pressure  

Microsoft Academic Search

The synthesis of aluminum nitride (AlN) powders was carried out by combustion of aluminum (Al) powder under low nitrogen pressure (?0.5 MPa) with carbon black (CB) as the dispersion agent to prevent the coalescence of the aluminum. The combustion was successful when the weight ratio between CB and Al, CB\\/Al, ranged from 0.02 to 1.5, while the combustion failed at

R.-C. Juang; C.-J. Lee; C.-C. Chen

2003-01-01

143

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

Microsoft Academic Search

Nine black powders found in Pompeii houses in three different types of bronze vessels (cylindrical theca atramentaria, unguentaries,\\u000a and aryballoi) were characterized in order to assess a correspondence between the composition and the type of vessel and,\\u000a possibly, to verify if these powders were inks or not. For the compositional characterization, a multi-analytical approach\\u000a was adopted, which involved the use

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

144

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

145

Sulfur Substitution in Oxyanions.  

NASA Astrophysics Data System (ADS)

Sulfide can react with oxyanions in two ways. In anions such as chromate, iodate or permanganate, the central metal(loid) is reduced rapidly. In anions such as molybdate, arsenate or antimonate, sulfur atoms substitute for oxygen atoms in the first coordination sphere. In the latter cases, the central metal(loid) often retains its high oxidation state in the final thioanion; however lower valent species, which tend to be coordinatively more labile, may be important reaction intermediates. Replacement of oxygen by sulfur "softens" oxyanions, in some cases making them strong binders of soft metals, like Cu, Ag, Au and Hg. These changes also can profoundly affect the geochemical fate of the metal(loids). Sulfur substitution in oxyanions can be extremely sluggish. Recently, computational chemistry has begun to yield information about sulfur substitution reactions that are too slow to be studied experimentally but yet are potentially important in geochemistry. Thioperrhenates, thiovanadates and thiotungstates are species whose geochemical roles, if any, remain to be determined. It is possible that sulfur substitution reactions are more important under hydrothermal conditions than at ambient temperatures. For example, germanate dominates the ambient-temperature chemistry of Ge, but in hydrothermal deposits this element occurs commonly in sulfide minerals.

Helz, G. R.

2008-12-01

146

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

147

Pipelined Backward Substitution The backward substitution is inherently  

E-print Network

Pipelined Backward Substitution (cont.) Step 2. x 0 + a 0;1 x 1 + a 0;2 x 2 = ¯ y 0 \\Gamma a 0;3 x 3 = ~ y 0 2 = ~ y 3 x 3 = ¯ y 3 x 4 = y 4 Pipelined Backward Substitution (cont.) Step 4. x 0 = y 0 \\Gamma a 0Pipelined Backward Substitution The backward substitution is inherently sequential, but may

Zhang, Jun

148

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

149

Carboxymethylation of Tamarind kernel powder  

Microsoft Academic Search

Tamarind kernel powder is a rich source of xyloglucan gum. The gum can be utilized in a number of industries. With a view to utilize the gum for broader applications, carboxymethylation of tamarind kernel powder was carried out. The reaction conditions were optimized with respect to concentration of sodium hydroxide, monochloroacetic acid, solvent ratio, reaction time, and reaction temperature. Carboxymethylation

Puja Goyal; Vineet Kumar; Pradeep Sharma

2007-01-01

150

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

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2011-04-01

151

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2010-04-01

152

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

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2012-04-01

153

Black tea  

MedlinePLUS

... depression (Tricyclic antidepressants)Black tea contains chemicals called tannins. Tannins can bind to many medications and decrease how ... your health provider.PhenothiazinesBlack tea contains chemicals called tannins. Tannins can bind to many medications and decrease ...

154

Copper thiocyanato complexes and cocaine - a case of 'black cocaine'.  

PubMed

The chemical composition of a black powder confiscated by German customs was elucidated. Black powders are occasionally used as a 'transporter' for cocaine and are obviously especially designed to cloak the presence of the drug. The material consisting of cocaine, copper, iron, thiocyanate, and graphite was approached by analytical tools and chemical modelling. Graphite is added to the material probably with the intention of masking the typical infrared (IR) fingerprints of cocaine and can be clearly detected by powder X-ray diffraction (XRD) and Raman spectroscopy. Cu(2+) and NCS(-) ions, when carefully reacted with cocaine hydrochloride, form the novel compound (CocH)2 [Cu(NCS)4 ] (CocH(+) ?=?protonated cocaine), which has been characterised by single crystal XRD, IR, NMR, UV/Vis absorption and EPR spectroscopy. Based on some further experiments the assumed composition of the original black powder is discussed. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24753444

Laussmann, Tim; Grzesiak, Ireneus; Krest, Alexander; Stirnat, Kathrin; Meier-Giebing, Sigrid; Ruschewitz, Uwe; Klein, Axel

2015-01-01

155

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.

156

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

157

Preparation of superconductor precursor powders  

DOEpatents

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

Bhattacharya, Raghunath (Littleton, CO); Blaugher, Richard D. (Evergreen, CO)

1995-01-01

158

powder in water  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

159

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

160

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

161

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

162

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

163

Shock compaction of molybdenum powder  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

164

Method for molding ceramic powders  

DOEpatents

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

Janney, M.A.

1990-01-16

165

Method for molding ceramic powders  

DOEpatents

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

Janney, Mark A. (Knoxville, TN)

1990-01-01

166

Structural studies of magnesium nitride fluorides by powder neutron diffraction  

SciTech Connect

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

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

2012-01-15

167

40 CFR 721.10497 - Substituted alkyl ester, hydrolysis products with silica and substituted silane (generic).  

Code of Federal Regulations, 2014 CFR

... false Substituted alkyl ester, hydrolysis products with silica and substituted...10497 Substituted alkyl ester, hydrolysis products with silica and substituted...generically as substituted alkyl ester, hydrolysis products with silica and...

2014-07-01

168

40 CFR 721.10497 - Substituted alkyl ester, hydrolysis products with silica and substituted silane (generic).  

Code of Federal Regulations, 2013 CFR

... false Substituted alkyl ester, hydrolysis products with silica and substituted...10497 Substituted alkyl ester, hydrolysis products with silica and substituted...generically as substituted alkyl ester, hydrolysis products with silica and...

2013-07-01

169

Rotary powder feed through apparatus  

DOEpatents

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

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

2001-01-01

170

Neutron detectors comprising boron powder  

SciTech Connect

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

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

2013-05-21

171

Luminescence of powdered uranium glasses  

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

172

Powder collection apparatus/method  

DOEpatents

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

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

1994-01-11

173

Powder collection apparatus/method  

DOEpatents

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

Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA); Moore, Jeffery A. (Ames, IA)

1994-01-11

174

Synthesis, structure, thermal stability, mechanical and antibacterial behaviour of lanthanum (La³?) substitutions in ?-tricalciumphosphate.  

PubMed

Five different concentrations of lanthanum (La(3+)) substituted ?-tricalcium phosphate [?-TCP, ?-Ca3(PO4)2] were formed through aqueous precipitation technique and the results were compared with stoichiometric ?-TCP. All the La(3+) substituted ?-TCP powders were characterized using XRD, FT-IR, XRF, Raman spectroscopy and Rietveld refinement of the XRD data. The results from the investigation confirmed the presence of La(3+) in rhombohedral ?-TCP structure. The substitution of higher sized of La(3+) led to the considerable enhancement in lattice parameters of ?-TCP crystal structure and La(3+) was found to have occupied the eight fold coordinated Ca (3) site of ?-TCP structure. La(3+) occupancy at the Ca (3) site resulted in the significant distortions of the associated PO4 tetrahedra, which were supported by the Raman and FT-IR spectroscopic techniques. La(3+) presence in the crystal lattice of ?-TCP also led to the delay in allotropic phase transformation of ?-TCP to ?-TCP till 1300°C, thus signifying the good thermal stability of La(3+) substituted ?-TCP powders. The antibacterial efficiency of La(3+) substituted ?-TCP powders was confirmed from the in vitro tests done on microbes such as Staphylococcus aureus and Escheria coli. Further, the presence of La(3+) in the crystal lattice of ?-TCP did not affect the hardness and Young's modulus values of ?-TCP. PMID:25175254

Meenambal, Rugmani; Singh, Ram Kishore; Nandha Kumar, P; Kannan, S

2014-10-01

175

Polyimides comprising substituted benzidines  

NASA Technical Reports Server (NTRS)

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

Harris, Frank W. (Inventor)

1991-01-01

176

Black Body  

Microsoft Academic Search

A black body was first defined by Gustav R. Kirchhoff (1824–87) in 1859 as an object that absorbs all radiation falling upon\\u000a it. Such a conception of an ideal black body was crucial for understanding heat radiation and its laws. Since a completely\\u000a black body does not exist in nature, it had to be constructed. Kirchhoff had already suggested that

Dieter Hoffmann

177

Powder lubrication of faults by powder rolls in gouge zones  

NASA Astrophysics Data System (ADS)

Powder-lubrication by fault gouge can be an effective mechanism of dynamic weakening of faults (Reches & Lockner, 2010); however, the physical mechanisms of this lubrication are poorly understood. While the flow of coarse-grained (> 100 ?m) materials, e.g. glass beads or quartz sand, was extensively studied, the flow of fine-grained (< 1 ?m) powders, e.g., fault-gouge and nano-powders, have remained enigmatic. We report here experimental results of a new efficient mechanism for powder lubrication. We conducted friction tests on high-velocity rotary shear apparatus (Reches & Lockner, 2010). Two types of experimental faults were tested: (1) faults made of solid, igneous rocks (granite, tonalite and diorite); and (2) fault-zones made of 2-3 mm thick layer of granular materials (oolites, calcite or gypsum) sheared in a confined cell. We performed 21 runs with total slip of 0.14-13 m, normal stress of 1.2-14.5 MPa, slip velocity of 0.012-0.97 m/s. The ultra-microscopic (SEM and AFM) analysis of the experimental slip surfaces revealed two outstanding features in 17 out of the 21 experiments: (1) localized fault-slip along Principal Slip Zones (PSZs) that are composed of a dense, shiny, cohesive crust, 0.5-1 micron thick, that overlaid a porous substrate, and (2) elongated rolls composed of gouge-powder into three-dimensional structures of closely-packed powder grains, (20-50 nm in size). The rolls are cylindrical, 0.75-1.4 micron wide, and 1.7-30 micron long, with smooth outer surface, and laminated, concentric layers of compacted grains. The rolls were exclusively found on the PSZs. Many rolls were destroyed fracturing and smearing on the PSZ, suggesting that the rolls underwent a life cycle of formation and destruction. Significant macroscopic friction reduction was measured in experiments with observed rolls, and no (or minor) friction reduction in the four experiments without rolls. The final, reduced friction coefficients have a general reciprocal relation to the rolls surface coverage, suggesting that increased development of rolls (= increasing surface coverage) enhanced fault weakening. We applied the Eldredge and Tabor (1955) model for rolling friction to the AFM observed morphology of the rolls and PSZs, and found good agreement between measured and modeled friction coefficients. We conclude that the measured friction reduction reflects a transition from sliding-dominated slip to rolling-dominated slip due to the presence and density of powder rolls. We further argue that powder rolling is an effective mechanism of powder lubrication, and that spontaneous growth of such rolls along crustal faults is likely to control earthquake weakening.

Chen, X.; Madden, A. S.; Reches, Z.

2013-12-01

178

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.

179

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. PMID:21767359

2011-01-01

180

Explicit Substitutions and All That  

NASA Technical Reports Server (NTRS)

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

Ayala-Rincon, Mauricio; Munoz, Cesar

2000-01-01

181

Are black holes totally black?  

E-print Network

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

A. A. Grib; Yu. V. Pavlov

2014-10-21

182

Properties of tape-cast Y-substituted strontium titanate for planar anode substrates in SOFC applications  

Microsoft Academic Search

This work evaluates the use of fine-grained yttrium-substituted strontium titanate powders for the preparation of planar anode\\u000a supported solid oxide fuel cells. Starting from a submicron-sized powder of Y-substituted strontium titanate Sr0.895Y0.07TiO3 (SYT), which was synthesised via spray pyrolysis followed by a grinding process, suspensions of high solid concentration\\u000a were prepared by steric stabilisation. From these suspensions, tape casting slurries

Pavel Vozdecky; Andreas Roosen; Qianli Ma; Frank Tietz; Hans Peter Buchkremer

2011-01-01

183

Rare-earth substitutions in Z-type hexaferrites  

NASA Astrophysics Data System (ADS)

Z-type hexaferrite (Ba 3Co 2Fe 24O 41) presents a gyromagnetic permeability whose resonance frequency stands around 2 GHz. The damping coefficient ? is less than 0.1. The influence on the damping coefficient of doping this ferrite by a rare-earth (La) has been studied. Powders have been synthesized by carbonate coprecipitation, dried and calcined at different temperatures. Different phases have been characterized by X-ray diffraction and magnetization measurements. Solubility in the range of weak concentrations has been verified. The synthesized powders were processed by slip casting in the presence of a magnetic field in order to align the particles. The microstructural and hyperfrequency characteristics have been evaluated. The influence of the substitution on anisotropy fields and damping are studied in comparison with pure Co 2Z, whose processing and properties have been optimized as a reference.

Jacquiod, Catherine; Autissier, Denis

1992-02-01

184

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

185

Black America.  

ERIC Educational Resources Information Center

The twenty-three contributors to this volume show that, despite racism, American blacks have independently developed some of their own cultural strengths. If these are correctly harnessed, they could provide important resources for the revitalization and development of the black community. The four parts of which this book is comprised are: (1)…

Szwed, John F., Ed.

186

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

PubMed Central

A range of crystalline and nano-sized carbonate- and silicate-substituted hydroxyapatite has been successfully produced by using continuous hydrothermal flow synthesis technology. Ion-substituted calcium phosphates are better candidates for bone replacement applications (due to improved bioactivity) as compared to phase-pure hydroxyapatite. Urea was used as a carbonate source for synthesising phase pure carbonated hydroxyapatite (CO3-HA) with ?5?wt% substituted carbonate content (sample 7.5CO3-HA) and it was found that a further increase in urea concentration in solution resulted in biphasic mixtures of carbonate-substituted hydroxyapatite and calcium carbonate. Transmission electron microscopy images revealed that the particle size of hydroxyapatite decreased with increasing urea concentration. Energy-dispersive X-ray spectroscopy result revealed a calcium deficient apatite with Ca:P molar ratio of 1.45 (±0.04) in sample 7.5CO3-HA. For silicate-substituted hydroxyapatite (SiO4-HA) silicon acetate was used as a silicate ion source. It was observed that a substitution threshold of ?1.1?wt% exists for synthesis of SiO4-HA in the continuous hydrothermal flow synthesis system, which could be due to the decreasing yields with progressive increase in silicon acetate concentration. All the as-precipitated powders (without any additional heat treatments) were analysed using techniques including Transmission electron microscopy, X-ray powder diffraction, Differential scanning calorimetry, Thermogravimetric analysis, Raman spectroscopy and Fourier transform infrared spectroscopy. PMID:22983020

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

2013-01-01

187

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

188

Mössbauer and magnetic study of silicon substituted cobalt ferrite  

NASA Astrophysics Data System (ADS)

Silicon substituted cobalt ferrites have been investigated for improved performance as stress sensing materials. A series of samples with the formulae CoSi x Fe2 - x O4 were prepared using conventional powder ceramic technique. X-ray diffraction patterns were taken to examine spinel crystal structures and energy dispersive spectrometry was done to confirm Si segregations at the grain boundaries. Magnetic and magneto-strictive measurements were carried out to evaluate the material performance. Mössbauer spectra were taken on selective samples to understand the cationic distribution responsible for the modification of properties. The variations are explained on the basis of the strength of the exchange interactions between cations, and anisotropy contributions of cobalt ions. The results demonstrate the possibility of controlling magnetic and magneto-mechanical properties such as Curie temperature and strain derivative through Co and Si substitutions.

Rao, G. S. N.; Caltun, O. F.; Rao, K. H.; Rao, B. Parvatheeswara; Gupta, Ajay; Rao, S. N. R.; Kumar, A. Mahesh

2008-06-01

189

Referential and nonreferential substitutional quantifiers  

Microsoft Academic Search

It is common to find philosophers claiming that it is possible to free the quantifiers - especially the particular (or so-called existential) quantifier - from questions of reference, existence, and ontology, by having recourse to what is now referred to as the substitutional interpretation of the quantifiers. Although there may be ontologically neutral uses of the substitutional interpretation, it is

Alex Orenstein

1984-01-01

190

La Zn Substituted Hexaferrites Prepared by Chemical Method  

NASA Astrophysics Data System (ADS)

La Zn substituted M-type Ba hexaferrite powders were prepared by sol-gel (Mx) and organometallic precursor (Sk) methods with Fe/Ba ratio of 11.6 and 10.8, respectively. The compositions (LaZn) x Ba1 - x Fe12 - x O19 with 0.0 ? x ? 0.6 were annealed at 975°C/2 h. The cationic site preferences of nonmagnetic La3+ instead of Ba2+ ions and Zn2+ instead of Fe3+ ions were determined by Mössbauer spectroscopy. The La3+ ions substitute the large Ba2+ ions at 2a site and for x ? 0.4 also at 4f2 site. The nearly all Zn2+ ions are placed at the 4f1 sites. The thermomagnetic analysis of ?(?) confirms that only the small substitutions for x ? 0.4 can be taken as a single-phase hexaferrites. The coercivity H c almost does not change at x = 0.2 for (Mx) samples and further decrease up to x = 0.6. For (Sk) samples at substitution x = 0.2 the values of H c are decreasing and at higher x the values nearly do not change. The Curie points, T c, slowly decrease with x for both (Mx) and (Sk) samples.

Grusková, A.; Lipka, J.; Papánová, M.; Sláma, J.; Tóth, I.; Kevická, D.; Mendoza, G.; Corral, J. C.; Šubrt, J.

2005-07-01

191

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

192

Storage study and quality evaluation of coconut protein powder.  

PubMed

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

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

2013-11-01

193

Effect of the carbon addition to filling powder ball-milled with oils on the critical current density in ex situ processed MgB2 tapes  

NASA Astrophysics Data System (ADS)

We have studied the effect of planetary ball-milling of filling powder with mineral and silicon oils on the carbon substitution in MgB2 and the critical current density (Jc) of Fe-sheathed MgB2 tapes fabricated through an ex situ process in a powder-in-tube (PIT) technique. The mineral oil is much more effective for the carbon substitution and hence the Jc enhancement of tapes than the silicon oil. The silicon oil hardly refines MgB2 and causes a slight carbon substitution, compared with the mineral oil. Low-temperature drying of the as-milled powder to remove the mineral oil is more effective for the Jc enhancement due to an enhanced carbon substitution. This is probably because the low-temperature drying leaves more organic material from decomposed oil which acts as a carbon source. However, the carbon substitution amount is just x = 0.04-0.05 in MgB2-xCx. Although the carbon addition to filling powder is effective in increasing the carbon substitution, the Jc properties of tapes degrade due to induced weak coupling.

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

2012-10-01

194

Automated dry powder dispenser for explosive components  

SciTech Connect

Sandia and Mound are developing a workcell that will automate the assembly of explosive components. Sandia is responsible for the automated powder dispenser subsystem. Automated dispensing of explosive powders in the past resulted in separation or segregation of powder constituents. The Automated Dry Powder Dispenser designed by Sandia achieves weight tolerances of {plus_minus}0.1 mg while keeping powderoxidizer separation to a minimum. A software control algorithm compensates fore changes in powder flow due to lot variations, temperature, humidity, and the amount of powder left in the system.

Garcia, P. [Sandia National Labs., Albuquerque, NM (United States); Salmonson, J.C. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1992-09-01

195

Automated dry powder dispenser for explosive components  

SciTech Connect

Sandia and Mound are developing a workcell that will automate the assembly of explosive components. Sandia is responsible for the automated powder dispenser subsystem. Automated dispensing of explosive powders in the past resulted in separation or segregation of powder constituents. The Automated Dry Powder Dispenser designed by Sandia achieves weight tolerances of {plus minus}0.1 mg while keeping powderoxidizer separation to a minimum. A software control algorithm compensates fore changes in powder flow due to lot variations, temperature, humidity, and the amount of powder left in the system.

Garcia, P. (Sandia National Labs., Albuquerque, NM (United States)); Salmonson, J.C. (EG and G Idaho, Inc., Idaho Falls, ID (United States))

1992-01-01

196

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

197

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

198

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

199

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

200

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

Code of Federal Regulations, 2014 CFR

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

2014-07-01

201

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

202

Advanced composites take a powder  

SciTech Connect

To a professional chemist with more than 25 years of industrial experience, the world of advanced composites is a fascinating new venue. Here resins and fibers come together in a completely synergistic partnership, achieving marvels of strength and light weight that make advanced composite materials virtually the only solution for challenging applications. In the late 1980s, Professor John Muzzy of the Georgia Institute of Technology, was intrigued by the physical properties of thermoplastics, and he developed a new way to bring the thermoplastic resins together with high-performance fibers. As part of the work Muzzy did with Lockheed and NASA he demonstrated that electrostatic powder coating was an attractive new method for combining thermoplastic resins with reinforcing fibers. Presentation of this work by Lockheed at a government-industry conference led to a new project for Muzzy, sponsored by NASA Langley. Powder prepregging proved to be the attractive alternative that NASA was looking for. While working on powder prepregging with LaRC-TPI, Muzzy and his colleagues developed methods for exposing all of the fibers to the powder to improve the distribution of the resin on the tow, a continuous bundle of filaments. Optimal resin distribution was achieved by spreading the moving tow. A very flexible towpreg was produced by maintaining the spread tow through the powder coating chamber and into the oven, where the resin particles were fused to the individual filaments. Muzzy's invention has enabled Custom Composite Materials, Inc. to offer resin/fiber combinations based on thermoplastic resins such as nylon and polypropylene. Beyond the expected advantages over epoxy thermoset systems, they are beginning to exploit a fundamental property of thermoplastic resins: viscoelasticity, which can be defined as the resistance to flow as a function of applied stress. Thermoplastics have a much higher viscoelasticity than thermosets.

Holty, D.W. (Custom Composite Materials, Inc., Atlanta, GA (United States))

1993-06-01

203

Polymer quenched prealloyed metal powder  

DOEpatents

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

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

2001-01-01

204

40 CFR 721.323 - Substituted acrylamide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted acrylamide. 721.323 Section 721.323 ...Substances § 721.323 Substituted acrylamide. (a) Chemical substance and significant...generically identified as substituted acrylamide (PMN P-90-1687) is subject...

2010-07-01

205

40 CFR 721.323 - Substituted acrylamide.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Substituted acrylamide. 721.323 Section 721.323 ...Substances § 721.323 Substituted acrylamide. (a) Chemical substance and significant...generically identified as substituted acrylamide (PMN P-90-1687) is subject...

2014-07-01

206

40 CFR 721.323 - Substituted acrylamide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Substituted acrylamide. 721.323 Section 721.323 ...Substances § 721.323 Substituted acrylamide. (a) Chemical substance and significant...generically identified as substituted acrylamide (PMN P-90-1687) is subject...

2013-07-01

207

40 CFR 721.323 - Substituted acrylamide.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Substituted acrylamide. 721.323 Section 721.323 ...Substances § 721.323 Substituted acrylamide. (a) Chemical substance and significant...generically identified as substituted acrylamide (PMN P-90-1687) is subject...

2012-07-01

208

40 CFR 721.1372 - Substituted nitrobenzene.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted nitrobenzene. 721.1372 Section 721.1372...Substances § 721.1372 Substituted nitrobenzene. (a) Chemical substance and significant...substance identified as a substituted nitrobenzene (PMN P-92-1125) is...

2010-07-01

209

40 CFR 721.1372 - Substituted nitrobenzene.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Substituted nitrobenzene. 721.1372 Section 721.1372...Substances § 721.1372 Substituted nitrobenzene. (a) Chemical substance and significant...substance identified as a substituted nitrobenzene (PMN P-92-1125) is...

2011-07-01

210

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

211

Enhancement of aged and denatured fingerprints using the cyanoacrylate fuming technique following dusting with amino acid-containing powders.  

PubMed

We have carried out experiments to investigate the aging of latent fingerprints deposited on black PVC over a period of 4-15 weeks. A thumbprint was used in each case and before deposition of the print the donor rubbed their thumb around their nose to add sebaceous deposits. We have studied the effect of heat, light, and moisture and we find that moisture is the most significant factor in the degradation of the latent print. We have attempted to enhance these latent prints by dusting with valine powder or powders composed of valine mixed with gold or red fluorescent commercial fingerprint powders. To make a direct comparison between "treated" and "untreated" prints, the prints were cut in half with one-half being "treated" and one-half not. Our studies show the best results being obtained when powders of valine and red fluorescent powders are applied prior to cyanoacrylate fuming. PMID:23316682

Nixon, Carly; Almond, Matthew J; Baum, John V; Bond, John W

2013-03-01

212

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

213

Processing and characterization of carob powder  

Microsoft Academic Search

The possibility of processing roasted carob powder using different time–temperature combinations has been studied. The physical and chemical characteristics of the prepared carob powders were also examined. The most acceptable roasted carob powder was obtained by roasting kibbled carob at 150°C for 60 min. The roasted carob powder contained 9.00, 5.82, 2.84 and 0.74% moisture, protein, ash and fat, respectively.

Ali K. Yousif; H. M. Alghzawi

2000-01-01

214

April 11, 2013 Powder Consolidation under Pressure  

E-print Network

April 11, 2013 Powder Consolidation under Pressure Wei-Jhe Sun Tablet, a consolidated powder structure, by considering the evolution of powder structure under compaction pressure.1 The mechanical, relative volume, and density to compaction pressure. A widely used equation is Heckel equation, which does

Thomas, David D.

215

Thermogram No Substitute for Mammogram  

MedlinePLUS

... Products Vaccines, Blood & Biologics Articulos en Espanol Thermogram No Substitute for Mammogram Search the Consumer Updates Section ... by mammography. The problem is that FDA has no evidence to support these claims. "Mammography is still ...

216

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

217

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

218

Anti-Corrosive Powder Particles  

NASA Technical Reports Server (NTRS)

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

Parker, Donald; MacDowell, Louis, III

2005-01-01

219

Marketplace analysis demonstrates quality control standards needed for black raspberry dietary supplements  

Technology Transfer Automated Retrieval System (TEKTRAN)

There is currently no standard for the minimum anthocyanin concentration a black raspberry dietary supplement must contain for legal sale in the US. All consumer available black raspberry products (n=19), packaged as dietary supplements or otherwise prepared (freeze-dried whole and pre-ground powder...

220

Partitioning the Variation in Mammalian Substitution Rates  

Microsoft Academic Search

We have used analysis of variance to partition the variation in synonymous and amino acid substitution rates between three effects (gene, lineage, and a gene-by-lineage interaction) in mammalian nuclear and mitochondrial genes. We find that gene effects are stronger for amino acid substitution rates than for synonymous substitution rates and that lineage effects are stronger for synonymous substitution rates than

Nick G. C. Smith; Adam Eyre-Walker

2003-01-01

221

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

222

Structural characterization of microwave-synthesized zinc-substituted cobalt ferrite nanoparticles  

Microsoft Academic Search

Microwave combustion technique modified by post treatment procedure is used to synthesize single-phase spinel ferrites of\\u000a cobalt, zinc, and substituted magnetic nanoparticles of typical size 390 Å. The post treatment does not alter the crystal\\u000a structure but increases the crystallinity. This is confirmed by powder x-ray diffraction and Fourier Transform Infrared (FTIR)\\u000a studies. Citric acid is used as a fuel.

Harshida Parmar; Rucha Desai; R. V. Upadhyay

2011-01-01

223

Black Hills  

Atmospheric Science Data Center

article title:  Drought in the Black Hills     View ... and western South Dakota remain in the midst of a severe drought. This set of images and maps from NASA's Multi-angle Imaging ... the 2000 and 2004 dates. As the vegetation faded with the drought, the  albedo  at the surface increased. Albedo measures the ...

2014-05-15

224

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.

NBC Learn

2010-10-07

225

Black English.  

ERIC Educational Resources Information Center

This paper, presented as part of a military lecture series given by the Division of Continuing Education and Community Service Speakers' Bureau of the University of Hawaii to military personnel at Schofield Barracks and Fort Shafter, investigates the origins and present status of Black English. A discussion of early studies in the Gullah dialect…

Bailey, Charles-James N.

226

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.

0000-00-00

227

Counseling Blacks  

ERIC Educational Resources Information Center

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

Vontress, Clemmont E.

1970-01-01

228

Red oak and black walnut growth increased with minesoil ripping  

Microsoft Academic Search

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

W. Clark Ashby

1996-01-01

229

Magnesium substitution in brushite cements.  

PubMed

The use of magnesium-doped ceramics has been described to modify brushite cements and improve their biological behavior. However, few studies have analyzed the efficiency of this approach to induce magnesium substitution in brushite crystals. Mg-doped ceramics composed of Mg-substituted ?-TCP, stanfieldite and/or farringtonite were reacted with primary monocalcium phosphate (MCP) in the presence of water. The cement setting reaction has resulted in the formation of brushite and newberyite within the cement matrix. Interestingly, the combination of SAED and EDX analyses of single crystal has indicated the occurrence of magnesium substitution within brushite crystals. Moreover, the effect of magnesium ions on the structure, and mechanical and setting properties of the new cements was characterized as well as the release of Ca(2+) and Mg(2+) ions. Further research would enhance the efficiency of the system to incorporate larger amounts of magnesium ions within brushite crystals. PMID:25428098

Alkhraisat, Mohammad Hamdan; Cabrejos-Azama, Jatsue; Rodríguez, Carmen Rueda; Jerez, Luis Blanco; Cabarcos, Enrique López

2013-01-01

230

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

PubMed

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

Wang, Kuen-Sheng; Chiou, Ing-Jia

2004-10-01

231

Black Secularism and Black Theology Vincent Lloyd  

E-print Network

1 Black Secularism and Black Theology Vincent Lloyd James Cone famously, or infamously, identified "white theology" as a major threat not only to black Christians but to Christianity in general. In 1970 threat has emerged: black secularism. White theology, purporting to be universal but actually

Doyle, Robert

232

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

233

40 CFR 721.1555 - Substituted phenyl azo substituted benzenediazonium salt.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

234

40 CFR 721.1555 - Substituted phenyl azo substituted benzenediazonium salt.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

235

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

236

40 CFR 721.1555 - Substituted phenyl azo substituted benzenediazonium salt.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

237

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

Code of Federal Regulations, 2014 CFR

...substituted phenyl) disulfonaphthyl azo, amine salt (generic). 721.2577 Section 721...substituted phenyl) disulfonaphthyl azo, amine salt (generic). Link to an amendment published...substituted phenyl) disulfonaphthyl azo, amine salt (PMNs P-00-0364 and...

2014-07-01

238

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

239

Powder handling for automated fuel processing  

SciTech Connect

Installation of the Secure Automated Fabrication (SAF) line has been completed. It is located in the Fuel Cycle Plant (FCP) at the Department of Energy's (DOE) Hanford site near Richland, Washington. The SAF line was designed to fabricate advanced reactor fuel pellets and assemble fuel pins by automated, remote operation. This paper describes powder handling equipment and techniques utilized for automated powder processing and powder conditioning systems in this line. 9 figs.

Frederickson, J.R.; Eschenbaum, R.C.; Goldmann, L.H.

1989-04-09

240

Modeling of laser cladding with powder injection  

Microsoft Academic Search

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

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

2004-01-01

241

Synthesis of mullite powders by acrylamide polymerization.  

SciTech Connect

Mullite (3Al{sub 2}O{sub 3} {center_dot} 2SiO{sub 2}) ceramics and composites are widely used. Synthesis of mullite powders, especially those that can be readily sintered, remains a focus of much current research. In support of recent efforts to fabricate mullite fibrous monoliths and to use superplastic flow to join ceramics, we have looked to synthesize reactive mullite powders. Recent advances in application of acrylamide polymers to ceramic synthesis offer promise of obtaining large quantities of high-quality powder at relatively low cost. We report here on synthesis from acrylamide monomers of mullite powders of two interesting particle sizes.

Sin, A.; Picciolo, J. J.; Lee, R. H.; Gutierrez-Mora, F.; Goretta, K. C.; Energy Technology; INPG-CNRS

2001-09-01

242

Dendritic microstructure in argon atomized superalloy powders  

NASA Technical Reports Server (NTRS)

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

Tewari, S. N.; Kumar, Mahundra

1986-01-01

243

Preparation techniques for ceramic waste form powder  

SciTech Connect

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

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

1997-08-01

244

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

SciTech Connect

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

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

2012-03-15

245

Emerging drugs of abuse: current perspectives on substituted cathinones  

PubMed Central

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

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

2014-01-01

246

Black Oesophagus  

PubMed Central

Acute oesophageal necrosis, also known as ‘Black Oesophagus’, is a rare endoscopic finding since its first description by Goldenberg in 1990. In endoscopic studies, the frequency ranged from 0.01% to 0.2%. The aetiology is undefined and is probably multifactorial. A 62-year-old woman, with chronic alcoholism, was admitted to the internal medicine department for dehydration and marked malnutrition problems. Melaena was detected, and oesophagogastroduodenoscopy showed black mucosa of the lower two-thirds of the oesophagus and candidiasis. The patient gradually recovered after conservative treatments (intravenous proton pump inhibitor and total parental nutrition) and fluconazole. Oesophagus stricture was developed after 1?month, and balloon dilatation was performed successfully. PMID:23365174

Pereira, Olga; Figueira-Coelho, João; Picado, Bárbara; Costa, José Neves

2013-01-01

247

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

248

Determination of crystal structure of polyaniline and substituted polyanilines through powder X-ray diffraction analysis  

Microsoft Academic Search

Polyaniline (PANI), poly(m-aminophenol) (PMAP) having a phenolic group as aromatic substituent and poly(m-nitroaniline) (PMNA) having a nitro group as aromatic substituent were synthesized by oxidative polymerization from their respective monomers. The degree of crystallinity, crystallite size, inter-chain separation and d-spacing were calculated from the experimental results, whereas crystal symmetry, space group, unit cell dimensions, agreement factors and molecular arrangement were

Sambhu Bhadra; Dipak Khastgir

2008-01-01

249

Metal Powder ProcessingMetal Powder Processing ME 4210: Manufacturing Processes and Engineering  

E-print Network

ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2009 2 #12;Powder General Motors automotive engines Source: Courtesy of Zenith ME 4210: Manufacturing Processes Processes and Engineering Prof. J.S. Colton © GIT 2009 4 #12;Making Powder-Metallurgy PartsMaking Powder

Colton, Jonathan S.

250

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

251

Preparation of Some Substituted Terephthalic Acids  

E-print Network

Preparation of Some Substituted Terephthalic Acids Susanna Branion and Vladimir Benin Department substituted terephthalic acids: 2-sulfomethylterephthalic acid (1) and 2-phosphonoterephthalic acid (2 for construction of acid-pendant polymer chains. Keywords: Acid-pendant polymers, arenephosphonic acids

Benin, Vladimir

252

Student Expectations and the Substitute Teacher.  

ERIC Educational Resources Information Center

Examines the problems substitute teachers have with conducting regular lessons when the class is unruly and offers a student questionnaire that gives an idea of what substitutes face as one solution. (JC)

Benedict, K. C.

1987-01-01

253

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

2011-10-01

254

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Benzenesulfonic acid, amino substituted phenylazo-. 721... § 721.1643 Benzenesulfonic acid, amino substituted phenylazo-. ...generically as a benzenesulfonic acid, amino substituted phenylazo-...

2011-07-01

255

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

256

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

257

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Benzenesulfonic acid, amino substituted phenylazo-. 721... § 721.1643 Benzenesulfonic acid, amino substituted phenylazo-. ...generically as a benzenesulfonic acid, amino substituted phenylazo-...

2014-07-01

258

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Benzenesulfonic acid, amino substituted phenylazo-. 721... § 721.1643 Benzenesulfonic acid, amino substituted phenylazo-. ...generically as a benzenesulfonic acid, amino substituted phenylazo-...

2012-07-01

259

Sintering study of nanocrystalline tungsten carbide powders  

Microsoft Academic Search

WC powder with an average grain size of 6 nm was obtained after high energy ball milling under protective gas atmosphere. The kinetics of densification was studied during sintering the powder in a dilatometer up to 1450 °C. The microstructure was investigated by TEM and high resolution SEM after various stages of sintering. The green density of the specimens was

G. R. Goren-Muginstein; S. Berger; A. Rosen

1998-01-01

260

Optical properties of cathodochromic powder screens  

NASA Astrophysics Data System (ADS)

Melamed's diffuse reflectance for powdered materials is discussed in conjunction with its application for cathodochromic powder screens. Adaptation of the model was introduced through the modification of geometrical factor xu which is now to be empirically established for given screen. Experimental evidence obtained for cathodochromic bromosodalite well supports proposed modification.

Maszara, W. P.; Todd, L. T., Jr.

1985-07-01

261

Insolubility of milk powder products A minireview  

E-print Network

Review Insolubility of milk powder products ­ A minireview Alan J. BALDWIN* Fonterra Research Abstract ­ In this paper, the formation of insolubility in milk powder is described, and the factors différences d'ordres de grandeur des taux d'humidité. L'effet des réactifs chimiques sur l'étendue de la

Boyer, Edmond

262

Applied fractal geometry and powder technology  

Microsoft Academic Search

Powder technology is important to many industries including mining, food processing, paint technology, powder metallurgy and space research. Applied fractal geometry is being used in these industries to describe and comprehend the complex interactions of many causes. The topics to be discussed in this review include, the study of important fractally structured pigments, the fractal structure of hazardous fumes, and

B. H. Kaye

1995-01-01

263

Slip casting and nitridation of silicon powder  

NASA Technical Reports Server (NTRS)

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.

1985-01-01

264

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

265

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

266

Wet powder seal for gas containment  

SciTech Connect

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.

1982-01-19

267

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

268

Expectations and Experiences of Substitute Teachers  

ERIC Educational Resources Information Center

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

Duggleby, Patricia; Badali, Sal

2007-01-01

269

Flow of Damp Powder in a Rotating Impervious Cone Flow of Damp Powder in a Rotating Impervious Cone  

E-print Network

the interfacial friction law for the flow of a damp powder past an impervious wall. 2 Introduction 2.1 The conicalFlow of Damp Powder in a Rotating Impervious Cone Flow of Damp Powder in a Rotating Impervious Cone, axisymmetric flow of damp powder within a rotating impervious cone. The powder spins with the cone

Fleck, Norman A.

270

Bone substitutes and bone formation  

Microsoft Academic Search

Summary  \\u000a Prompted by severe problems in autogeneic and allogeneic bone transplantation, intensive efforts were made to find sufficient\\u000a substitutes. A main demand on these materials, especially in healing of osseous defects, is to achieve results comparable\\u000a to those of auto- or allografts. These must be related to their biomechanical and particularly to their biological properties,\\u000a i. e. the ability to

H. Stützle; K. Hallfeldt; H. Mandelkow; S. Keßler; L. Schweiberer

1998-01-01

271

21 CFR 520.1696b - Penicillin G powder.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Penicillin G powder. 520.1696b Section...NEW ANIMAL DRUGS § 520.1696b Penicillin G powder. (a) Specifications. Each gram of powder contains penicillin G potassium equivalent to...

2013-04-01

272

21 CFR 520.1696b - Penicillin G powder.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Penicillin G powder. 520.1696b Section...NEW ANIMAL DRUGS § 520.1696b Penicillin G powder. (a) Specifications. Each gram of powder contains penicillin G potassium equivalent to...

2014-04-01

273

Iridium-Catalyzed Allylic Substitution  

NASA Astrophysics Data System (ADS)

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

Hartwig, John F.; Pouy, Mark J.

274

Resonant photodissociation in substituted benzenes  

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

275

A new approach to assess the chemical composition of powder deposits damaging the stone surfaces of historical monuments.  

PubMed

The issue of conservation of the monumental heritage worldwide is mainly related to atmospheric pollution that causes the degradation of stone surfaces. The powder deposits present on the stone monuments reflect the composition of the aerosol particulate matter (PM) to which the surfaces are exposed, so the chemical characterization of the outermost damaged layers is necessary in order to adopt mitigation measurements to reduce PM emissions. In the present paper, a new analytical approach is proposed to investigate the chemical composition of powder deposits present on Angera stone, a dolomitic rock used in the Richini courtyard, a masterpiece of Lombard Baroque and placed in Milan. Inorganic and organic components present in these deposits have been analyzed by IC (ion chromatography) and a new approach mainly bases on thermal analyses, respectively. Gypsum is the main inorganic constituent indicating a composition similar to that of black crusts, hard black patina covering the degraded building surfaces. Ammonium nitrate present in the powder is able to react with the stone substrate to form magnesium nitrate which can migrate into the porous stone. The carbonaceous fraction powder deposits (i.e. OC?=?Organic Carbon and EC?=?Elemental Carbon) have been quantified by a new simple thermal approach based on carbon hydrogen nitrogen (CHN) analysis. The presence of high concentration of EC confirms that the powder deposits are evolving to black crust. Low values of water-soluble organic carbon (WSOC, determined by total organic carbon-TOC), with respect to what is normally found in PM, may indicate a migration process of organic substances into the stone with a worsening of the conservation conditions. The presence of heavy metals of anthropogenic origin and acting as catalysts in the black crust formation process has been highlighted by SEM-EDS (electron microscopy coupled with an energy dispersive spectrometer) as well. PMID:25408080

Fermo, Paola; Turrion, Raquel Gonzalez; Rosa, Mario; Omegna, Alessandra

2014-11-20

276

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

277

Preparation and characterization of uranyl oxalate powders  

NASA Astrophysics Data System (ADS)

Uranyl oxalate powders are prepared by adding 0.5 M oxalic acid solution to the uranyl nitrate (UNH) solutions purified with TBP extraction from dissolution of the Canada originated U 3O 8 commercial concentrate. Uranyl oxalate powders are identified by chemical analysis, TGA/DTG analysis, IR analysis and by single-crystal X-ray diffraction. The effects of the precipitation conditions on the powder properties are determined. A broad particle size distribution is obtained for all precipitation variants. These powders including very fine particles are difficult to filter and are not free flowing. The reactor and mixing type have a considerable effect on the powder properties of the uranyl oxalate powders. It was possible to ameliorate the filtration and the flowability to a certain degree using a conical air agitated reactor. The flowability of these powders is 0.4 g/s with a specific surface area 6.64 m 2/g and an average particle size of 11 ?m.

Tel, H.; Bülbül, M.; Eral, M.; Alta?, Y.

1999-10-01

278

Dirty Black Holes and Hairy Black Holes  

Microsoft Academic Search

An approach based on considerations of the nonclassical energy momentum tensor outside the event horizon of a black hole provides additional physical insight into the nature of discrete quantum hair on black holes and its effect on black hole temperature. Our analysis both extends previous work based on the Euclidean action techniques and corrects an omission in that work. We

Lawrence M. Krauss; Hong Liu; Junseong Heo

1996-01-01

279

Dry powder formulation of simvastatin.  

PubMed

Objectives: This study focuses on the development of a dry powder inhaler (DPI) formulation of simvastatin (SV), and the effects of SV on the respiratory epithelium. Methods: Micronised SV samples were prepared by dry jet-milling. The long-term chemical stability and physicochemical properties of the formulations were characterised in terms of particles size, morphology, thermal and moisture responses. Furthermore, in vitro aerosol depositions were performed. The formulation was evaluated for cell viability and its effect on cilia beat activity, using ciliated nasal epithelial cells in vitro. The formulation transport across an established air interface Calu-3 bronchial epithelial cells and its ability to reduce mucus secretion was also investigated. Results: The particle size of the SV formulation and its aerosol performance were appropriate for inhalation therapy. Moreover, the formulation was found to be non-toxic to pulmonary epithelia cells and cilia beat activity up to a concentration of 10(-6) M. Transport studies revealed that SV has the ability to penetrate into airway epithelial cells and is converted into its active SV hydroxy acid metabolite. Single dose of SV DPI also decreased mucus production after 4 days of dosing. Conclusion: This therapy could potentially be used for the local treatment of diseases like chronic obstructive pulmonary disease, cystic fibrosis, and bronchiectasis given its anti-inflammatory effects and ability to reduce mucus production. PMID:25244365

Tulbah, Alaa S; Ong, Hui Xin; Morgan, Lucy; Colombo, Paolo; Young, Paul M; Traini, Daniela

2014-09-22

280

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

281

Pulmonary drug delivery by powder aerosols.  

PubMed

The efficacy of pharmaceutical aerosols relates to its deposition in the clinically relevant regions of the lungs, which can be assessed by in vivo lung deposition studies. Dry powder formulations are popular as devices are portable and aerosolisation does not require a propellant. Over the years, key advancements in dry powder formulation, device design and our understanding on the mechanics of inhaled pharmaceutical aerosol have opened up new opportunities in treatment of diseases through pulmonary drug delivery. This review covers these advancements and future directions for inhaled dry powder aerosols. PMID:24818765

Yang, Michael Yifei; Chan, John Gar Yan; Chan, Hak-Kim

2014-11-10

282

Formulation considerations for dry powder inhalers.  

PubMed

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

Cordts, Eike; Steckel, Hartwig

2014-06-01

283

Use This Test to Spruce Up Your Substitute Teacher Program.  

ERIC Educational Resources Information Center

Presents and interprets an 18-question test to determine how well a school's substitute teacher program functions. Topics covered include substitute teacher screening and preparation, lists of substitutes, lesson plans, staff and student evaluation of substitutes, substitutes' salaries, legal considerations, and making substitutes feel needed.…

Sendor, Elizabeth

1982-01-01

284

Black Holes FAQ  

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. It provides rationale for existence of Black Holes despite lack of direct observation.

Bunn, Ted

285

Efficient black markets?  

Microsoft Academic Search

This paper investigates analytically the welfare effects of black-market activities that firms undertake to evade taxes. The desirability of a black market is linked to the attributes of the goods supplied by black-market firms. The analysis identifies cases where a black market reduces (increases) the distortionary impact of taxation on the allocation of resources across the goods that the government

Carl Davidson; Lawrence Martin; John Douglas Wilson

2007-01-01

286

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

DOEpatents

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

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

1999-01-01

287

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

288

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

289

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

290

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

291

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

292

21 CFR 73.2647 - Copper powder.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

293

Screening and classification of ceramic powders  

NASA Technical Reports Server (NTRS)

A summary is given of the classification technology of ceramic powders. Advantages and disadvantages of the wet and dry screening and classification methods are discussed. Improvements of wind force screening devices are described.

Miwa, S.

1983-01-01

294

Metal powder production by gas atomization  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

295

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2011 CFR

...starch (including food starch-modified as prescribed in § 172.892 of this chapter). (5) Dried corn sirup. (6) Gum acacia. Vanilla powder may contain one or any mixture of two or more of the anticaking ingredients specified in...

2011-04-01

296

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2013 CFR

...starch (including food starch-modified as prescribed in § 172.892 of this chapter). (5) Dried corn sirup. (6) Gum acacia. Vanilla powder may contain one or any mixture of two or more of the anticaking ingredients specified in...

2013-04-01

297

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2010 CFR

...starch (including food starch-modified as prescribed in § 172.892 of this chapter). (5) Dried corn sirup. (6) Gum acacia. Vanilla powder may contain one or any mixture of two or more of the anticaking ingredients specified in...

2010-04-01

298

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2012 CFR

...starch (including food starch-modified as prescribed in § 172.892 of this chapter). (5) Dried corn sirup. (6) Gum acacia. Vanilla powder may contain one or any mixture of two or more of the anticaking ingredients specified in...

2012-04-01

299

21 CFR 169.179 - Vanilla powder.  

Code of Federal Regulations, 2014 CFR

...starch (including food starch-modified as prescribed in § 172.892 of this chapter). (5) Dried corn sirup. (6) Gum acacia. Vanilla powder may contain one or any mixture of two or more of the anticaking ingredients specified in...

2014-04-01

300

Magnesium Powder Metallurgy: Process and Materials Opportunities  

NASA Astrophysics Data System (ADS)

The major efforts in magnesium alloy development for automotive applications have concentrated on creep resistant alloys produced by permanent mould and high-pressure die casting routes. While large components, such as crankcases, will never be produced by powder metallurgy, there are smaller components in and around the powertrain which could be fabricated from powder precursors. This article will explore the potential of some of the more recent powder compaction developments, and discuss the alloy development strategies that emerge for magnesium-based components as a consequence of these process developments. In particular, the viability of direct powder extrusion of semi-finished product, using conventional extrusion or equal channel angular processing, combined with T6 heat treatments, will be considered.

Bettles, Colleen J.

2008-06-01

301

Advances in beryllium powder consolidation simulation  

SciTech Connect

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

Reardon, B.J.

1998-12-01

302

Continuous blending of dry pharmaceutical powders  

E-print Network

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

Pernenkil, Lakshman

2008-01-01

303

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

304

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

305

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

306

21 CFR 73.2646 - Bronze powder.  

Code of Federal Regulations, 2014 CFR

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

2014-04-01

307

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

308

21 CFR 73.2645 - Aluminum powder.  

Code of Federal Regulations, 2014 CFR

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

2014-04-01

309

Synthesis and characterization of magnesium substituted biphasic mixtures of controlled hydroxyapatite/{beta}-tricalcium phosphate ratios  

SciTech Connect

The present paper investigates the preparation of magnesium (Mg) substituted biphasic mixtures of different hydroxyapatite (HAP)/{beta}-tricalcium phosphate ({beta}-TCP) ratios through aqueous precipitation method. The concentrations of added magnesium (Mg) were varied with the calcium in order to obtain constant (Ca+Mg)/P ratios of 1.67 ranging from 1.62+0.05, 1.58+0.09 and 1.54+0.13, respectively. The as prepared powders were calcined at different temperatures to study the phase behaviour and thermal stability. The powders were characterized by the following analytical techniques: TG-DTA, X-ray diffraction and FT-IR. The results have shown that substitution of Mg in the calcium-deficient apatites resulted in the formation of biphasic mixtures of different HAP/{beta}-TCP ratios after heating above 700 deg. C. The ratios of the formation of phase mixtures were dependent on the calcium deficiency in the apatites with the higher deficiency having the strongest impact on the increased formation of {beta}-TCP and the substituted Mg was found to stabilize the {beta}-TCP phase. - Graphical abstract: Role of Mg in the behaviour of calcium-deficient apatites during calcination to form biphasic mixtures.

Kannan, S. [Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal); Lemos, I.A.F. [Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal); Rocha, J.H.G. [Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal); Ferreira, J.M.F. [Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro (Portugal)]. E-mail: jmf@cv.ua.pt

2005-10-15

310

Sensory substitution as an artificially acquired synaesthesia.  

PubMed

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

Ward, Jamie; Wright, Thomas

2014-04-01

311

Biaxially textured articles formed by powder metallurgy  

DOEpatents

A biaxially textured alloy article comprises Ni powder and at least one powder selected from the group consisting of Cr, W, V, Mo, Cu, Al, Ce, YSZ, Y, Rare Earths, (RE), MgO, CeO.sub.2, and Y.sub.2 O.sub.3 ; compacted and heat treated, then rapidly recrystallized to produce a biaxial texture on the article. In some embodiments the alloy article further comprises electromagnetic or electro-optical devices and possesses superconducting properties.

Goyal, Amit (Knoxville, TN); Williams, Robert K. (Knoxville, TN)

2001-01-01

312

Synthesis and processing of monosized oxide powders  

DOEpatents

Uniform-size, high-purity, spherical oxide powders are formed by hydrolysis of alkoxide precursors in dilute alcoholic solutions. Under controlled conditions (concentrations of 0.03 to 0.2 M alkoxide and 0.2 to 1.5 M water, for example) oxide particles on the order of about 0.05 to 0.7 microns can be produced. Methods of doping such powders and forming sinterable compacts are also disclosed. 6 figs.

Barringer, E.A.; Fegley, M.B. Jr.; Bowen, H.K.

1985-09-24

313

Adjustable Powder Injector For Vacuum Plasma Sprayer  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

314

Synthesis and processing of monosized oxide powders  

DOEpatents

Uniform-size, high-purity, spherical oxide powders are formed by hydrolysis of alkoxide precursors in dilute alcoholic solutions. Under controlled conditions (concentrations of 0.03 to 0.2 M alkoxide and 0.2 to 1.5 M water, for example) oxide particles on the order of about 0.05 to 0.7 micron can be produced. Methods of doping such powders and forming sinterable compacts are also disclosed.

Barringer, Eric A. (Waltham, MA); Fegley, Jr., M. Bruce (Waban, MA); Bowen, H. Kent (Belmont, MA)

1985-01-01

315

Relative flow rates of explosive powders  

SciTech Connect

A study was performed to determine the relative flow rates of various explosive powders and evaluate their adaptability for use in automated dispensing systems. Results showed that PBX 9407, LX-15, RX-26-BH, and HNAB are potential candidates for use in these systems. It was also shown that powders with graphite and stearate additives generated the least amount of static and were the easiest to handle.

Willson, V.P.

1988-05-31

316

Ti Multicomponent Alloy Bulks by Powder Metallurgy  

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

317

Multiphase electrodispersion precipitation of zirconia powders  

SciTech Connect

The multiphase electrodispersion precipitation of zirconia powders has been done The multiphase in the electric dispersion reactor (EDR). This paper presents the first results obtained where the bench-scale EDR unit was operated in the continuous mode to synthesize 130 {+-} 2 g of ZrO{sub 2} powder in approximately 12 h. An aqueous solution of zirconyl nitrate was dispersed and precipitated in a 2-ethyl-l-hexanol continuous phase containing 0.012 {und M} to 0.12 {und M} ammonia. A gravity settler was used to remove soft agglomerates of the ZrO{sub 2} particles from the organic solvent. Electric bed filtration was employed to remove the fines from the solvent, which was then recycled. The particle-size distribution was varied by changing the electric field strength. At high field strengths (approximately 20 kV/cm), the particle sizes ranged from approximately 0.1 to 5 {mu}m. The dried powder had a consistency of talcum powder. Microwave and conventional heating experiments showed that the powders were sinterable. The BET surface area of the powders ranged from approximately 20 to 90 m{sup 2}/g.

Harris, M.T.; Sisson, W.G.; Scott, T.C.; Basaran, O.A.; Byers, C.H. [Oak Ridge National Lab., TN (United States). Chemical Technology Division; Ren, W.; Meek, T.T. [Univ. of Tennessee, Knoxville, TN (United States). Materials Science and Engineering Dept.

1994-12-31

318

Cement from magnesium substituted hydroxyapatite.  

PubMed

Brushite cement may be used as a bone graft material and is more soluble than apatite in physiological conditions. Consequently it is considerably more resorbable in vivo than apatite forming cements. Brushite cement formation has previously been reported by our group following the mixture of nanocrystalline hydroxyapatite and phosphoric acid. In this study, brushite cement was formed from the reaction of nanocrystalline magnesium-substituted hydroxyapatite with phosphoric acid in an attempt to produce a magnesium substituted brushite cement. The presence of magnesium was shown to have a strong effect on cement composition and strength. Additionally the presence of magnesium in brushite cement was found to reduce the extent of brushite hydrolysis resulting in the formation of HA. By incorporating magnesium ions in the apatite reactant structure the concentration of magnesium ions in the liquid phase of the cement was controlled by the dissolution rate of the apatite. This approach may be used to supply other ions to cement systems during setting as a means to manipulate the clinical performance and characteristics of brushite cements. PMID:15875256

Lilley, K J; Gbureck, U; Knowles, J C; Farrar, D F; Barralet, J E

2005-05-01

319

ACCURACY IN POWDER DIFFRACTION IV Critical parameters for  

E-print Network

ACCURACY IN POWDER DIFFRACTION IV Critical parameters for instrument alignment and performance validation of XRD instrumentation Gaithersburg, MD, USA April 22-25, 2013 1Accuracy in Powder Diffraction IV · Accuracy in Powder Diffraction starts with accurate powder diffraction data ­ Also from laboratory

Magee, Joseph W.

320

Concentration mode of the powder stream in coaxial laser cladding  

Microsoft Academic Search

The blown powder laser cladding process has recently been greatly enhanced by the development of a coaxial powder feed system. It provides a new route to generate the metal parts directly from CAD drawings. The performance of the coaxial powder feeder depends on various gas flow streams which significantly affect the distribution mode of the powder stream and the deposition

Jehnming Lin

1999-01-01

321

Polycyclic Aromatic Triptycenes: Oxygen Substitution Cyclization Strategies  

E-print Network

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

VanVeller, Brett

322

Quantum Black Holes. Black Hole Temperature without a Black Hole  

E-print Network

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

Victor Berezin

2008-12-24

323

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

SciTech Connect

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

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

2012-01-15

324

Crystal structure and magnetic properties of Pr- and Ti-substituted La{sub 2}RuO{sub 5}  

SciTech Connect

Highlights: • Synthesis of polycrystalline Pr and Ti co-substituted La{sub 2}RuO{sub 5} with soft chemistry. • Investigation of structure–property relationship of the dimerization transition. • Additive behavior of structural changes caused by either Pr or Ti substitution. • Additive behavior of ht-phase paramagnetism of Pr and Ti substitution. • Additive influence of Pr and Ti substitution on the dimerization transition. - Abstract: Polycrystalline samples of Pr- and Ti-substituted La{sub 2}RuO{sub 5} were prepared applying a soft-chemistry route based on the thermal decomposition of citrate-stabilized precursors. The simultaneous substitution on the La-sites by Pr and on the Ru-sites by Ti results in samples of the composition La{sub 2?x}Pr{sub x}Ru{sub 1?y}Ti{sub y}O{sub 5} with 0 ? x ? 0.75 and 0 ? y ? 0.4. The crystal structures of these compounds were analyzed by Rietveld refinement of powder X-ray diffraction patterns. For pure La{sub 2}RuO{sub 5} a structural transition from a monoclinic room-temperature modification to a triclinic low-temperature structure was found at 161 K. This structural change is linked to a low-temperature long-range ordered spin-singlet ground state formed by Ru{sup 4+} spin-moments. Both the structural transition and the formation of the singlet ground state become progressively suppressed with higher Ti contents, while the Pr substitution has only a minor influence on the dimerization. The behavior of the Curie–Weiss temperatures can be explained assuming two almost independent magnetic sublattices corresponding to the ruthenium and the rare-earth ions, respectively. For all investigated properties, i.e. crystal structure, magnetic susceptibilities, and dimerization temperature T{sub d}, a completely additive behavior of the effects of Pr-substitution and Ti-substitution is observed.

Riegg, S., E-mail: stefan.riegg@physik.uni-augsburg.de [Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, D-86159 Augsburg (Germany); Loidl, A. [Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, D-86159 Augsburg (Germany); Reller, A. [Resource Strategy, University of Augsburg, D-86159 Augsburg (Germany); Ebbinghaus, S.G. [Solid State Chemistry, Martin-Luther University Halle-Wittenberg, D-06099 Halle (Germany)

2013-11-15

325

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

326

50 Omega characteristic impedance low-pass metal powder filters  

Microsoft Academic Search

We have fabricated several 50 Omega characteristic impedance low-pass metal powder filters. The filters are made with bronze or copper metal powder with varying amounts of metal powder in a metal powder\\/epoxy mixture. Our goal is to make a filter with a characteristic impedance Z=50 Omega at frequencies up to 10 GHz. Using a 78% bronze powder\\/epoxy mixture in a

F. P. Milliken; J. R. Rozen; G. A. Keefe; R. H. Koch

2007-01-01

327

50 ? characteristic impedance low-pass metal powder filters  

Microsoft Academic Search

We have fabricated several 50 ? characteristic impedance low-pass metal powder filters. The filters are made with bronze or copper metal powder with varying amounts of metal powder in a metal powder\\/epoxy mixture. Our goal is to make a filter with a characteristic impedance Z=50 ? at frequencies up to 10 GHz. Using a 78% bronze powder\\/epoxy mixture in a

F. P. Milliken; J. R Rozen; G. A. Keefe; R. H. Koch

2007-01-01

328

Slip casting nano-particle powders for making transparent ceramics  

DOEpatents

A method of making a transparent ceramic including the steps of providing nano-ceramic powders in a processed or unprocessed form, mixing the powders with de-ionized water, the step of mixing the powders with de-ionized water producing a slurry, sonifing the slurry to completely wet the powder and suspend the powder in the de-ionized water, separating very fine particles from the slurry, molding the slurry, and curing the slurry to produce the transparent ceramic.

Kuntz, Joshua D. (Livermore, CA); Soules, Thomas F. (Livermore, CA); Landingham, Richard Lee (Livermore, CA); Hollingsworth, Joel P. (Oakland, CA)

2011-04-12

329

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

330

Interaction between laser beam and powder stream in the process of laser cladding with powder feeding  

Microsoft Academic Search

Based on Lambert-Beer theorem and Mie's theory, the attenuation of laser power by a powder stream was calculated and the laser intensity distribution at the laser spot on the surface of a workpiece was obtained. Simultaneously, the temperature distribution of the powder particles arriving at different sites on the surface of the workpiece was computed following the heat equilibrium principle.

Yan-Lu Huang; Gong-Ying Liang; Jun-Yi Su; Jian-Guo Li

2005-01-01

331

What happened to blood substitutes?  

PubMed

Concerns about the safety and adequacy of the blood supply have fostered twenty years of research into the so-called "blood substitutes" among them the oxygen carriers based on modified hemoglobin. Although none of these materials has yet been licensed for use in North America or Europe, the results of research and clinical trials have increased our understanding of oxygen delivery and its regulation. In particular, the examination of the basis for the vasoactivity observed with some of the hemoglobin based oxygen carriers has led to the insight that several colligative properties of hemoglobin solutions, such as their diffusion coefficient for oxygen, viscosity and colloid oncotic pressure, are important determinants of efficacy. PMID:16326128

Stowell, C P

2005-11-01

332

Die-target for dynamic powder consolidation  

DOEpatents

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

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

1985-06-27

333

Die-target for dynamic powder consolidation  

DOEpatents

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

Flinn, John E. (Idaho Falls, ID); Korth, Gary E. (Blackfoot, ID)

1986-01-01

334

Dynamic compaction of tungsten carbide powder.  

SciTech Connect

The shock compaction behavior of a tungsten carbide powder was investigated using a new experimental design for gas-gun experiments. This design allows the Hugoniot properties to be measured with reasonably good accuracy despite the inherent difficulties involved with distended powders. The experiments also provide the first reshock state for the compacted powder. Experiments were conducted at impact velocities of 245, 500, and 711 m/s. A steady shock wave was observed for some of the sample thicknesses, but the remainder were attenuated due to release from the back of the impactor or the edge of the sample. The shock velocity for the powder was found to be quite low, and the propagating shock waves were seen to be very dispersive. The Hugoniot density for the 711 m/s experiment was close to ambient crystal density for tungsten carbide, indicating nearly complete compaction. When compared with quasi-static compaction results for the same material, the dynamic compaction data is seen to be significantly stiffer for the regime over which they overlap. Based on these initial results, recommendations are made for improving the experimental technique and for future work to improve our understanding of powder compaction.

Gluth, Jeffrey Weston; Hall, Clint Allen; Vogler, Tracy John; Grady, Dennis Edward

2005-04-01

335

Inhaled Dry Powder Formulations for Treating Tuberculosis.  

PubMed

Tuberculosis is the second leading cause of death from infectious diseases. Although anti-tubercular drugs have been traditionally administered orally, there is a growing interest in delivering drugs via the pulmonary route using nebulisers or dry powder inhalers. Drugs in dry powder inhalers (DPI) are stable and DPI are user-friendly compared to nebulisation which is time consuming, inconvenient and inefficient and requires special equipment. For tuberculosis treatment, drugs should target alveolar macrophages that harbour microorganisms and/or maintain high drug concentration at the infection site in the lung. Drug particles include micro-particles or nanoparticles. Powders can be engineered by micronisation, crystallisation, spray drying, freeze drying and particle coating approaches. The formulation may contain single or combination drugs. This paper will provide an update on current status of TB, its pathogenesis, current treatment strategies, shortcomings of current oral or parenteral delivery strategies, pulmonary delivery devices, advantages of pulmonary delivery of powder formulations, formulation approaches and pharmacokinetic studies of pulmonary delivery of powders for inhalation. PMID:25030114

Das, Shyamal; Tucker, Ian; Stewart, Peter

2014-07-16

336

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

Microsoft Academic Search

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

Frank Messner

2002-01-01

337

Rietveld refinement, electrical properties and magnetic characteristics of Ca-Sr substituted barium hexaferrites  

Microsoft Academic Search

M–type Ca-Sr substituted barium hexaferrites having compositions BaFe12O19, Ba0.5Ca0.5Fe12O19 and Ba0.5Ca0.25Sr0.25Fe12O19 have been synthesized by commercial solid state reaction method. The effects of doping on structural, dielectric and magnetic properties were systematically investigated. The Rietveld refinement of X-ray powder diffraction data revealed that the samples possess single hexagonal phase with space group P63\\/mmc, with two molecules in the unit cell

Ashima Hooda; Sujata Sanghi; Ashish Agarwal; Reetu Dahiya

338

Low-Temperature Firing of Substituted M-Type Hexagonal Ferrites for Multilayer Inductors  

Microsoft Academic Search

Co\\/Ti-substituted M-type $\\\\hbox{BaFe}_{12-2{\\\\rm x}}\\\\hbox{Co}_{\\\\rm x}\\\\hbox{Ti}_{\\\\rm x}\\\\hbox{O}_{19}$ ferrites were investigated for multilayer inductor applications. Single-phase ferrite powders were prepared at 1000$^{\\\\circ}\\\\hbox{C}$ through the mixed oxide route. After sintering at 1300$^{\\\\circ}\\\\hbox{C}$ a maximum permeability of $\\\\mu^{\\\\prime}=37$ is observed for ${\\\\rm x}=1.2$. The addition of a glass sintering aid shifts the temperature of maximum shrinkage down to below 900 $^{\\\\circ}\\\\hbox{C}$ and dense samples

Silvia Bierlich; Jörg Topfer

2012-01-01

339

Synthesis, characterization and nonlinear optical properties of symmetrically substituted dibenzylideneacetone derivatives  

NASA Astrophysics Data System (ADS)

We report here the nonlinear optical (NLO) properties of eight bis-chalcones of D-?-A-?-D type. These dibenzylideneacetone (DBA) derivatives are synthesized by Claisen-Schmidt reaction. The compounds are characterized by UV-vis, FTIR, 1H NMR, 13C NMR, mass spectroscopy and powder XRD. By substituting different groups (electron withdrawing and electron donating) at 'para' and 'meta' positions of the aromatic ring, we observed an enhancement in second harmonic generation with substitution at 'para' position. These compounds have also showed higher two-photon absorption compared to other chalcones reported in literature. These compounds, exhibiting both second and third order NLO effects, are plausible candidate materials in photonic devices.

Sunil Kumar Reddy, N.; Badam, Rajashekar; Sattibabu, Romala; Molli, Muralikrishna; Sai Muthukumar, V.; Siva Sankara Sai, S.; Rao, G. Nageswara

2014-11-01

340

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

341

SIMILARITY NETWORK FOR SEMANTIC WEB SERVICES SUBSTITUTION  

E-print Network

SIMILARITY NETWORK FOR SEMANTIC WEB SERVICES SUBSTITUTION Chantal Cherifi LE2I Laboratory, Burgundy is performed on a benchmark of semantically annotated Web services. Results show that this approach allows a more detailed analysis of substitutable Web services. Keywords - Semantic Web services, Functional

Paris-Sud XI, Université de

342

Educators Take Another Look at Substitutes  

ERIC Educational Resources Information Center

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

Zubrzycki, Jaclyn

2012-01-01

343

Amino acid substitution matrices from protein blocks  

Microsoft Academic Search

Methods for alignment of protein sequences typically measure similarity by using a substitution matrix with scores for all possible exchanges of one amino acid with another. The most widely used matrices are based on the Dayhoff model of evolutionary rates. Using a different approach, we have derived substitution matrices from about 2000 blocks of aligned sequence segments characterizing more than

Steven Henikoff; Jorja G. Henikoff

1992-01-01

344

Carboranylmethylene-substituted phosphazenes and polymers thereof  

NASA Technical Reports Server (NTRS)

Carboranylmethylene-substituted cyclophosphazenes are described which can be thermally polymerized into carboranylmethylene-substituted phosphazene polymers. The polymers are useful as thermally stable coatings. Also, due to the characteristics of these polymers in acting as a ligand for transition metals, metalocarboranylmethylene phosphazene polymers are described which can act as immobilized catalyst systems, and are electrically conductive and superconductive.

Allcock, H. R.; Scopelianos, A. G. (inventors)

1984-01-01

345

Savvy Substitutions. Tricks of the Trade.  

ERIC Educational Resources Information Center

Provides ideas for using throwaways and substitutions, such as homemade objects and everyday items, as art supplies and other resources in the art classroom. Throwaways and substitutions are a way to be environmentally caring, to extend meager supplies, and to supplement art budgets. (CMK)

Guhin, Paula

2000-01-01

346

Substitute Your Way to a Real Job  

ERIC Educational Resources Information Center

For some, substitute teaching is a career choice. However, for the majority of new teachers, it is often a necessary gateway to landing a first job. Either way, it is a great way to sharpen one's skills. This article presents tips from principals, teachers, and human resource directors to make the most of the substitute teaching experience…

Stephens, Cathy

2013-01-01

347

Dry powder coating of pharmaceuticals: a review.  

PubMed

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

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

2013-12-01

348

Preparation of nickel powders in nonaqueous media.  

NASA Astrophysics Data System (ADS)

Precipitation of nickel powder is usually carried out in aqueous media. Nonaqueous solvents such as ethanolamines offer several advantages. The effective temperature range extends to the higher temperatures needed for the reduction of nickel at atmospheric pressure, a reaction that is also facilitated by the basicity of the medium. Tests were carried out for the preparation of submicrometre nickel powders by the reduction of metal salts using various ethanolamines (monoethanolamine - MEA, diethanolamine - DEA, and triethanolamine - TEA) as solvents. Hydrazine (N2H4) was used as the reducing agent. The basicity, polarity, viscosity and boiling point of the reaction medium all affect the reactions. By changing the reaction conditions and the anionic component of the precursor salt, it was possible to alter the purity and morphology of the nickel powders obtained and the average particle size, except in the case of MEA where no reduction occured. The products were subsequently characterised by chemical analysis and by scanning electron microscopy.

Macek, Jadran; Degen, Andrej

349

The Effect of Te Substitution for Sb on Thermoelectric Properties of Tetrahedrite  

NASA Astrophysics Data System (ADS)

We present the study of the effect of Te substitution on the thermoelectric properties for Sb in Cu12Sb4- x Te x S13 tetrahedrite compounds with x ranging from 0.2 to 1.5 in the temperature range of room temperature to 723 K. Powder x-ray diffraction and electron microscopy results indicate a successful homogenous substitution without the alteration of the crystal structure or the introduction of secondary phases. Thermoelectric property measurements show that the excess electrons from Te during the substitution fill the unoccupied levels near the top of the valence bands in pure Cu12Sb4S13 compound, moving the Fermi level closer to the top of the valence bands. This leads to an enhancement in thermopower but also to an increase in electrical resistivity. Overall, the reduction in total thermal conductivity gives rise to improved ZT values in all substituted samples. The highest ZT value obtained in this study is 0.92 at 723 K for x = 1, which is comparable to that of other p-type bulk thermoelectric materials.

Lu, Xu; Morelli, Donald

2014-06-01

350

Atomization methods for forming magnet powders  

DOEpatents

The invention encompasses methods of utilizing atomization, methods for forming magnet powders, methods for forming magnets, and methods for forming bonded magnets. The invention further encompasses methods for simulating atomization conditions. In one aspect, the invention includes an atomization method for forming a magnet powder comprising: a) forming a melt comprising R.sub.2.1 Q.sub.13.9 B.sub.1, Z and X, wherein R is a rare earth element; X is an element selected from the group consisting of carbon, nitrogen, oxygen and mixtures thereof; Q is an element selected from the group consisting of Fe, Co and mixtures thereof; and Z is an element selected from the group consisting of Ti, Zr, Hf and mixtures thereof; b) atomizing the melt to form generally spherical alloy powder granules having an internal structure comprising at least one of a substantially amorphous phase or a substantially nanocrystalline phase; and c) heat treating the alloy powder to increase an energy product of the alloy powder; after the heat treatment, the alloy powder comprising an energy product of at least 10 MGOe. In another aspect, the invention includes a magnet comprising R, Q, B, Z and X, wherein R is a rare earth element; X is an element selected from the group consisting of carbon, nitrogen, oxygen and mixtures thereof; Q is an element selected from the group consisting of Fe, Co and mixtures thereof; and Z is an element selected from the group consisting of Ti, Zr, Hf and mixtures thereof; the magnet comprising an internal structure comprising R.sub.2.1 Q.sub.13.9 B.sub.1.

Sellers, Charles H. (Idaho Falls, ID); Branagan, Daniel J. (Idaho Falls, ID); Hyde, Timothy A. (Idaho Falls, ID)

2000-01-01

351

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.

John Stewart

352

Stratification Among Blacks By Black Authors  

ERIC Educational Resources Information Center

The tragic consequence of differentiation between light and dark skinned slaves was the blacks' own acceptance of color distinctions as bases for judging each other's value; many early black writers not only observed, but experienced this color value system. The stratification was of concern to them because it was part of the real situation.…

Trent, Toni

1971-01-01

353

Synthesis of ultrafine powders by microwave heating  

DOEpatents

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

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

1987-04-24

354

Dry powder mixes comprising phase change materials  

DOEpatents

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft.

Salyer, Ival O. (Dayton, OH)

1995-01-01

355

Dry powder mixes comprising phase change materials  

DOEpatents

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft.

Salyer, Ival O. (Dayton, OH)

1994-01-01

356

Dry powder mixes comprising phase change materials  

DOEpatents

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft. 3 figs.

Salyer, I.O.

1995-12-26

357

Dry powder mixes comprising phase change materials  

DOEpatents

A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft. 3 figures.

Salyer, I.O.

1994-12-06

358

Determination of porosity variations in powder beds.  

PubMed

A gamma-ray attenuation technique for detecting local porosity variations in packings of pharmaceutical powders has been developed and assessed. It proved necessary to employ an empirical expression describing the attenuation coefficient of the model material, lactose, as a function of porosity. The precision of measurement of local porosity can be pre-selected due to the statistical basis of the method, and local porosity measurements with 95% confidence intervals of +/- 0.005 can readily be carried out. A method of producing grey-scale images of porosity distributions has been employed to enable the degree of inhomogeneity of a powder bed to be seen. PMID:6124616

Woodhead, P J; Hardy, J G; Newton, J M

1982-06-01

359

Advanced NDE Technologies for Powder Metal Components  

SciTech Connect

Nondestructive evaluation encompasses numerous technologies that assess materials and determine important properties. This paper demonstrates the applicability of several of these technologies to the field of powder metallurgy. The usual application of nondestructive evaluation is to detect and quantify defects in fully sintered product. But probably its most appealing role is to sense problems earlier in the manufacturing process to avoid making defects at all. Also nondestructive evaluation can be incorporated into the manufacturing processes to monitor important parameters and control the processes to produce defect free product. Nondestructive evaluation can characterize powders, evaluate components in the green state, monitor the sintering process, and inspect the final component.

Martin, P; Haskins, J; Thomas, G; Dolan, K

2003-05-01

360

Life inside black holes  

E-print Network

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

V. I. Dokuchaev

2012-03-05

361

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

362

Black hole shadows in accretion disks and spin parameters of black holes: Massive black holes and stellar mass black holes  

Microsoft Academic Search

Can we determine spin parameters of black holes by observations of black hole shadows in accretion disks? In order to answer this question, we have investigated shapes and positions of black hole shadows in optically thick accretion disks around Kerr black holes. In conclusion, in order to measure black hole spin parameters from shapes and positions of black hole shadows,

Rohta Takahashi

2004-01-01

363

Black holes, black strings and cosmological constant  

E-print Network

We present a review of black holes and black string solutions available in the $d$-dimensional Einstein and Einstein-Maxwell model in the presence of a cosmological constant. Due to the cosmological constant, the equations do not admit explicit solutions for generic values of the parameters and numerical methods are necessary to construct the solutions. Several new features of the solutions are discussed, namely their stability and the occurrence of non-uniform black strings which depend non-trivially on the co-dimension. Black string solutions are further constructed for the Einstein-Gauss-Bonnet model. The influence of the Gauss-Bonnet term on the domain of existence of the black strings is discussed in details.

Yves Brihaye

2009-06-10

364

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

SciTech Connect

Regional correlations, from the southern to northern Black Hills and across the central Powder River basin to the Bighorn Mountains, serve as the frame work for a depositional model of middle Minnelusa sediments. In the eastern part of the study area, deposition took place in a carbonate sabkha environment. During transgressive periods, most of this region was covered by a restricted shallow sea. In the northern Black Hills, close to the limit of the transgression, deposition occurred in a coastal dune setting. During regressions, the sabkha prograded westward toward the Lusk embayment. Coastal dune fields to the north and isolated dune complexes to the south migrated southwestward across this prograding sabkha. West of the Lusk embayment, deposition occurred in a sand dominated tidal-flat environment during transgressions and along the coastal edge of an eolian sand sea during regression.

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

1985-05-01

365

[Identification of pearl powder using microscopic infrared reflectance spectroscopy].  

PubMed

Pearl is a precious ornament and traditional Chinese medicine, which application history in China is more than 2000 years. It is well known that the chemical ingredients of shell and pearl are very similar, which all of them including calcium carbonate and various amino acids. Generally, shell powders also can be used as medicine; however, its medicinal value is much lower than that of pearl powders. Due to the feature similarity between pearl powders and shell powders, the distinguishment of them by detecting chemical composition and morphology is very difficult. It should be noted that shell powders have been often posing as pearl powders in markets, which seriously infringes the interests of consumers. Identification of pearl powder was investigated by microscopic infrared reflectance spectroscopy, and pearl powder as well as shell powder was calcined at different temperatures for different time before infrared reflectance spectroscopy analysis. The experimental results indicated that when calcined at 400 °C for 30 minutes under atmospheric pressure, aragonite in pearl powder partly transformed into calcite, while aragonite in shell powder completely transformed into calcite. At the same time, the difference in phase transition between the pearl powders 'and shell powders can be easily detected by using the microscopic infrared reflectance spectroscopy. Therefore, based on the difference in their phase transition process, infrared reflectance spectroscopy can be used to identify phase transformation differences between pearl powder and shell powder. It's more meaningfully that the proposed infrared reflectance spec- troscopy method was also investigated for the applicability to other common counterfeits, such as oyster shell powders and abalone shell powders, and the results show that the method can be a simple, efficiently and accurately method for identification of pearl powder. PMID:25532338

Zhang, Xuan; Hu, Chao; Yan, Yan; Yang, Hai-Feng; Li, Jun-Fang; Bai, Hua; Xi, Guang-Cheng; Liao, Jie

2014-09-01

366

Black Bean Burrito Ingredients  

E-print Network

& SU, VSU, and the U.S.D.A. cooperating. Edwin J. Jones, Director, Virginia Cooperative ExtensionBlack Bean Burrito Ingredients: 15 ounces black beans, canned, drained and rinsed 10 ounces corn cheddar cheese, low-fat, shredded 8 whole wheat flour tortillas Directions 1. Drain and rinse black beans

Liskiewicz, Maciej

367

color: DIVPOP; black: low;  

E-print Network

black: low DIVPOP red: middle DIVPOP green: high DIVPOP · Quality of vesicles black: low death rate redcolor: DIVPOP; black: low; red: middle; green: high. Vesicle dynamcis · Maturation rate comparison: the models & models of the models Neutral Step Mort. Step Div. ODEprediction 0 0.02 0.04 0.06 0.08 0.1 Death

Utrecht, Universiteit

368

IMAGES OF BLACK AMERICANS  

PubMed Central

Images of Black Americans are becoming remarkably diverse, enabling Barack Obama to defy simple-minded stereotypes and succeed. Understood through the Stereotype Content Model’s demonstrably fundamental trait dimensions of perceived warmth and competence, images of Black Americans show three relevant patterns. Stereotyping by omission allows non-Blacks to accentuate the positive, excluding any lingering negativity but implying it by its absence; specifically, describing Black Americans as gregarious and passionate suggests warmth but ignores competence and implies its lack. Obama’s credentials prevented him from being cast as incompetent, though the experience debate continued. His legendary calm and passionate charisma saved him on the warmth dimension. Social class subtypes for Black Americans differentiate dramatically between low-income Blacks and Black professionals, among both non-Black and Black samples. Obama clearly fit the moderately warm, highly competent Black-professional subtype. Finally, the campaign’s events (and nonevents) allowed voter habituation to overcome non-Blacks’ automatic emotional vigilance to Black Americans. PMID:24235974

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

2013-01-01

369

The Nearest Black Hole  

NASA Technical Reports Server (NTRS)

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

Oliversen, Ronald (Technical Monitor); Garcia, Michael

2005-01-01

370

BLACK ROOT ROT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Black Root Rot Prepared by G. S. Abawi, Revised by L.E. Hanson Black root rot is caused by Thielaviopsis basicola (syn. Chalara elegans). The pathogen is widely distributed, can infect more than 130 plant species in 15 families, and causes severe black root rot diseases in ornamentals and crops suc...

371

Thermal Conductivity of Powder Aggregates and Porous Compacts  

NASA Astrophysics Data System (ADS)

A new equation for calculating the thermal conductivity of metal powder aggregates and sintered metal powder compacts is proposed. In this equation, the effective conductivity of the powder system is a function of the conductivity of the fully dense material, the porosity of the system, and the tap porosity of the starting powder. The new equation is applicable to powder systems, from the tap porosity to zero porosity, as well as to consolidated powders. The proposed equation has been experimentally validated by fitting to data from other authors. The results confirm a good agreement with theoretical predictions.

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

2012-12-01

372

40 CFR 721.320 - Acrylamide-substituted epoxy.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Acrylamide-substituted epoxy. 721.320 ...Chemical Substances § 721.320 Acrylamide-substituted epoxy. (a) Chemical...chemical substance identified generically as acrylamide-substituted epoxy (PMN...

2014-07-01

373

40 CFR 721.320 - Acrylamide-substituted epoxy.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Acrylamide-substituted epoxy. 721.320 ...Chemical Substances § 721.320 Acrylamide-substituted epoxy. (a) Chemical...chemical substance identified generically as acrylamide-substituted epoxy (PMN...

2013-07-01

374

40 CFR 721.10254 - Substituted acrylamide (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Substituted acrylamide (generic). 721.10254 Section...Substances § 721.10254 Substituted acrylamide (generic). (a) Chemical substance...identified generically as substituted acrylamide (PMN P-09-390) is subject...

2013-07-01

375

40 CFR 721.10254 - Substituted acrylamide (generic).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Substituted acrylamide (generic). 721.10254 Section...Substances § 721.10254 Substituted acrylamide (generic). (a) Chemical substance...identified generically as substituted acrylamide (PMN P-09-390) is subject...

2014-07-01

376

40 CFR 721.320 - Acrylamide-substituted epoxy.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Acrylamide-substituted epoxy. 721.320 ...Chemical Substances § 721.320 Acrylamide-substituted epoxy. (a) Chemical...chemical substance identified generically as acrylamide-substituted epoxy (PMN...

2010-07-01

377

40 CFR 721.10254 - Substituted acrylamide (generic).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Substituted acrylamide (generic). 721.10254 Section...Substances § 721.10254 Substituted acrylamide (generic). (a) Chemical substance...identified generically as substituted acrylamide (PMN P-09-390) is subject...

2012-07-01

378

40 CFR 721.320 - Acrylamide-substituted epoxy.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Acrylamide-substituted epoxy. 721.320 ...Chemical Substances § 721.320 Acrylamide-substituted epoxy. (a) Chemical...chemical substance identified generically as acrylamide-substituted epoxy (PMN...

2012-07-01

379

40 CFR 721.320 - Acrylamide-substituted epoxy.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Acrylamide-substituted epoxy. 721.320 ...Chemical Substances § 721.320 Acrylamide-substituted epoxy. (a) Chemical...chemical substance identified generically as acrylamide-substituted epoxy (PMN...

2011-07-01

380

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2013-07-01

381

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2011-07-01

382

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2014-07-01

383

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2012-07-01

384

40 CFR 721.4596 - Diazo substituted carbomonocyclic metal complex.  

Code of Federal Regulations, 2010 CFR

...Diazo substituted carbomonocyclic metal complex. 721.4596 Section 721.4596 ...Diazo substituted carbomonocyclic metal complex. (a) Chemical substance and significant...diazo substituted carbomonocyclic metal complex (PMN P-94-1039) is subject...

2010-07-01

385

40 CFR 721.1760 - Substituted benzotriazole derivatives.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

386

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

387

40 CFR 721.2527 - Substituted diphenylazo dye (generic name).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted diphenylazo dye (generic name). 721.2527 Section... § 721.2527 Substituted diphenylazo dye (generic name). (a) Chemical substance...generically as a substituted diphenylazo dye (PMN P-95-514) is subject to...

2010-07-01

388

40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.  

Code of Federal Regulations, 2014 CFR

...Substituted naphthalenesulfonic acid, alkali salt. 721.5278 Section 721.5278 ...Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical substance and significant...substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to...

2014-07-01

389

40 CFR 721.5278 - Substituted naphthalenesulfonic acid, alkali salt.  

Code of Federal Regulations, 2011 CFR

...Substituted naphthalenesulfonic acid, alkali salt. 721.5278 Section 721.5278 ...Substituted naphthalenesulfonic acid, alkali salt. (a) Chemical substance and significant...substituted naphthalenesulfonic acid, alkali salt (PMN P-95-85) is subject to...

2011-07-01

390

40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.  

Code of Federal Regulations, 2010 CFR

...Substituted halogenated pyridinol, alkali salt. 721.8900 Section 721.8900 ...Substituted halogenated pyridinol, alkali salt. (a) Chemical substances and significant...substituted halogenated pyridinols, alkali salts (PMNs P-88-1271 and...

2010-07-01

391

40 CFR 721.8900 - Substituted halogenated pyridinol, alkali salt.  

Code of Federal Regulations, 2013 CFR

...Substituted halogenated pyridinol, alkali salt. 721.8900 Section 721.8900 ...Substituted halogenated pyridinol, alkali salt. (a) Chemical substances and significant...substituted halogenated pyridinols, alkali salts (PMNs P-88-1271 and...

2013-07-01

392

40 CFR 721.640 - Amine substituted metal salts.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Amine substituted metal salts. 721.640 Section 721.640 Protection... § 721.640 Amine substituted metal salts. (a) Chemical substance and significant...identified generically as amine substituted metal salts (PMNs...

2014-07-01

393

40 CFR 721.3565 - Ethylenediamine, substituted, sodium salt.  

Code of Federal Regulations, 2011 CFR

... Ethylenediamine, substituted, sodium salt. 721.3565 Section 721.3565 ...Ethylenediamine, substituted, sodium salt. (a) Chemical substance and significant...as ethylenediamine, substituted, sodium salt (PMN P-97-328) is subject to...

2011-07-01

394

40 CFR 721.8670 - Alkylcyano substituted pyridazo benzoate.  

Code of Federal Regulations, 2010 CFR

...false Alkylcyano substituted pyridazo benzoate. 721.8670 Section 721.8670...8670 Alkylcyano substituted pyridazo benzoate. (a) Chemical substance and significant...as an alkylcyano substituted pyridazo benzoate (PMN P-94-1129) is subject...

2010-07-01

395

Substituted Hydroxyapatites with Antibacterial Properties  

PubMed Central

Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency. PMID:24949423

Kolmas, Joanna; Groszyk, Ewa; Kwiatkowska-Ró?ycka, Dagmara

2014-01-01

396

Proton glass freezing in hydrated lysozyme powders  

Microsoft Academic Search

At room temperature, the dielectric relaxation of hydrated powder of the protein lysozyme is known to be due to protons migrating between ionized side chains. A recent study of this relaxation at lower temperatures suggested a behavior typical of proton glasses. An analysis of the complex dielectric susceptibility by a temperature-frequency plot presented here has revealed that ergodicity is broken

Adrijan Levstik; Cene Filipic; Zdravko Kutnjak; Giorgio Careri; Giuseppe Consolini; Fabio Bruni

1999-01-01

397

Balanced mechanical resonator for powder handling device  

NASA Technical Reports Server (NTRS)

A system incorporating a balanced mechanical resonator and a method for vibration of a sample composed of granular material to generate motion of a powder sample inside the sample holder for obtaining improved analysis statistics, without imparting vibration to the sample holder support.

Sarrazin, Philippe C. (Inventor); Brunner, Will M. (Inventor)

2012-01-01

398

Screening mail for powders using terahertz technology  

NASA Astrophysics Data System (ADS)

Following the 2001 Anthrax letter attacks in the USA, there has been a continuing interest in techniques that can detect or identify so-called 'white powder' concealed in envelopes. Electromagnetic waves (wavelengths 100-500 ?m) in the terahertz frequency range penetrate paper and have short enough wavelengths to provide good resolution images; some materials also have spectroscopic signatures in the terahertz region. We report on an experimental study into the use of terahertz imaging and spectroscopy for mail screening. Spectroscopic signatures of target powders were measured and, using a specially designed test rig, a number of imaging methods based on reflection, transmission and scattering were investigated. It was found that, contrary to some previous reports, bacterial spores do not appear to have any strong spectroscopic signatures which would enable them to be identified. Imaging techniques based on reflection imaging and scattering are ineffective in this application, due to the similarities in optical properties between powders of interest and paper. However, transmission imaging using time-of-flight of terahertz pulses was found to be a very simple and sensitive method of detecting small quantities (25 mg) of powder, even in quite thick envelopes. An initial feasibility study indicates that this method could be used as the basis of a practical mail screening system.

Kemp, Mike

2011-11-01

399

Characterization of nal powders for rocket propulsion  

NASA Astrophysics Data System (ADS)

Nanosized metal powders are known to significantly improve both solid and hybrid rocket performance, but have some drawbacks in terms of cost, safety, and possible influence on propellant mechanical properties. Performance enhancement through nanosized metal or metal hydride addition to solid fuels is currently under investigation also for hybrid propulsion. Therefore, a preburning characterization of the powders used in solid propellant or fuel manufacturing is useful to assess their effects on the ballistic properties and engine performance. An investigation concerning the comparative characterization of several aluminum powders having different particle size, age, and coating is presented. Surface area, morphology, chemical species concentration and characteristics, surface passivation layers, surface and subsurface chemical composition, ignition temperature and ignition delay are investigated. The aim of this characterization is to experimentally assess the effect of the nAl powder properties on ballistic characteristics of solid fuels and solidrocket composite-propellant performance, showing an increase in terms of Is caused by the decrease of two-phase losses in solid and a possible significant rf increase in hybrid rockets.

Merotto, L.; Galfetti, L.; Colombo, G.; DeLuca, L. T.

2011-10-01

400

Low density fragile states in cohesive powders  

E-print Network

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

Paul B. Umbanhowar; Daniel I. Goldman

2005-12-24

401

Strength enhancement process for prealloyed powder superalloys  

NASA Technical Reports Server (NTRS)

A technique involving superplastic processing and high pressure autoclaving was applied to a nickel base prealloyed powder alloy. Tensile strengths as high as 2865 MN/sq m at 480 C were obtained with as-superplastically deformed material. Appropriate treatments yielding materials with high temperature tensile and stress rupture strengths were also devised.

Waters, W. J.; Freche, J. C.

1977-01-01

402

Pressing behavior of atomized iron powders  

Microsoft Academic Search

The optimum zinc stearate content, ensuring the greatest compressibility of a powder at a given pressing pressure, is determined mainly by the volume of interparticle pores. The higher the density of a compact and the smaller the size of its pores, the smaller is the amount of zinc stearate it can hold. The weakening action of zinc stearate, which manifests

A. F. Zhornyak; V. E. Oliker

1981-01-01

403

Ceramic powder synthesis by spray pyrolysis  

Microsoft Academic Search

A variety of spray pyrolysis (SP) techniques have been developed to directly produce ceramic powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solute diffusion in the droplet and solvent evaporation from the droplet surface is presented

Gary L. Messing; Shi-Chang Zhang; Gopal V. Jayanthi

1993-01-01

404

Sol-Gel Synthesis Of Aluminoborosilicate Powders  

NASA Technical Reports Server (NTRS)

Application of sol-gel process to synthesis of aluminoborosilicate powders shows potential for control of microstructures of materials. Development of materials having enhanced processing characteristics prove advantageous in extending high-temperature endurance of fibrous refractory composite insulation made from ceramic fibers.

Bull, Jeffrey; Leiser, Daniel; Selvaduray, Guna

1992-01-01

405

MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON  

EPA Science Inventory

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

406

Black Hole Chemistry  

E-print Network

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

David Kubiznak; Robert B. Mann

2014-04-08

407

Searching for Black Holes  

NASA Technical Reports Server (NTRS)

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

Garica, M.

2001-01-01

408

Nonstationary analogue black holes  

E-print Network

We study the existence of analogue nonstationary spherically symmetric black holes. The prime example is the acoustic model (cf. [V], [U]). We consider also a more general class of metrics that could be useful in other physical models of analogue black and white holes. We give examples of the appearance of black holes and of disappearance of white holes. We also discuss the relation between the apparent and the event horizons for the case of analogue black holes. In the end we study the inverse problem of determination of black or white holes by boundary measurements for the spherically symmetric nonstationary metrics.

Gregory Eskin

2014-11-26

409

Phantom Black Holes  

E-print Network

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

C. J. Gao; S. N. Zhang

2006-04-20

410

Black holes without boundaries  

E-print Network

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

Alex B. Nielsen

2008-09-10

411

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

412

Magnetized static black Saturn  

SciTech Connect

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

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

2008-06-15

413

Magnetized static black Saturn  

E-print Network

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

Stoytcho S. Yazadjiev

2008-02-06

414

Phenolic Acids in the Gastrointestinal (GI) Tract of Pigs Fed Black Raspberry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Black raspberries (BRB) contain high levels of anthocyanins and have been demonstrated to be chemopreventative against colon cancer. In this study, pigs were fed freeze-dried BRB powder and three segments of the GI tract (small intestine, cecum and colon; 4 hours after feeding) were collected for an...

415

Improved Small-Particle Powders for Plasma Spraying  

NASA Technical Reports Server (NTRS)

Improved small-particle powders and powder-processing conditions have been developed for use in plasma spray deposition of thermal-barrier and environmental barrier coatings. Heretofore, plasma-sprayed coatings have typically ranged in thickness from 125 to 1,800 micrometers. As explained below, the improved powders make it possible to ensure complete coverage of substrates at unprecedently small thicknesses of the order of 25 micrometers. Plasma spraying involves feeding a powder into a hot, high-velocity plasma jet. The individual powder particles melt in the plasma jet as they are propelled towards a substrate, upon which they splat to build up a coating. In some cases, multiple coating layers are required. The size range of the powder particles necessarily dictates the minimum thickness of a coating layer needed to obtain uniform or complete coverage. Heretofore, powder particle sizes have typically ranged from 40 to 70 micrometers; as a result, the minimum thickness of a coating layer for complete coverage has been about 75 micrometers. In some applications, thinner coatings or thinner coating layers are desirable. In principle, one can reduce the minimum complete-coverage thickness of a layer by using smaller powder particles. However, until now, when powder particle sizes have been reduced, the powders have exhibited a tendency to cake, clogging powder feeder mechanisms and feed lines. Hence, the main problem is one of synthesizing smaller-particle powders having desirable flow properties. The problem is solved by use of a process that begins with a spray-drying subprocess to produce spherical powder particles having diameters of less than 30 micrometers. (Spherical-particle powders have the best flow properties.) The powder is then passed several times through a commercial sifter with a mesh to separate particles having diameters less than 15 micrometers. The resulting fine, flowable powder is passed through a commercial fluidized bed powder feeder into a plasma spray jet.

Nguyen, QuynhGiao, N.; Miller, Robert A.; Leissler, George W.

2005-01-01

416

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

SciTech Connect

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

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

2012-07-27

417

Characterisation of titanium-titanium boride composites processed by powder metallurgy techniques  

SciTech Connect

In this work, a detailed characterisation of titanium-titanium boride composites processed by three powder metallurgy techniques, namely, hot isostatic pressing, spark plasma sintering and vacuum sintering, was conducted. Two composites with different volume percents of titanium boride reinforcement were used for the investigation. One was titanium with 20% titanium boride, and the other was titanium with 40% titanium boride (by volume). Characterisation was performed using X-ray diffraction, electron probe micro analysis - energy dispersive spectroscopy and wavelength dispersive spectroscopy, image analysis and scanning electron microscopy. The characterisation results confirm the completion of the titanium boride reaction. The results reveal the presence of titanium boride reinforcement in different morphologies such as needle-shaped whiskers, short agglomerated whiskers and fine plates. The paper also discusses how mechanical properties such as microhardness, elastic modulus and Poisson's ratio are influenced by the processing techniques as well as the volume fraction of the titanium boride reinforcement. - Highlights: Black-Right-Pointing-Pointer Ti-TiB composites were processed by HIP, SPS and vacuum sintering. Black-Right-Pointing-Pointer The completion of Ti-TiB{sub 2} reaction was confirmed by XRD, SEM and EPMA studies. Black-Right-Pointing-Pointer Hardness and elastic properties of Ti-TiB composites were discussed. Black-Right-Pointing-Pointer Processing techniques were compared with respect to their microstructure.

Selva Kumar, M., E-mail: sel_mcet@yahoo.co.in [Department of Mechanical Engineering, Dr. Mahalingam College of Engineering and Technology, Pollachi-642003 (India); Chandrasekar, P.; Chandramohan, P. [School of Engineering, Professional Group of Institutions, Coimbatore-641662 (India)] [School of Engineering, Professional Group of Institutions, Coimbatore-641662 (India); Mohanraj, M. [Department of Mechanical Engineering, Info Institute of Engineering, Coimbatore-641107 (India)] [Department of Mechanical Engineering, Info Institute of Engineering, Coimbatore-641107 (India)

2012-11-15

418

A users' guide to understanding therapeutic substitutions.  

PubMed

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

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

2014-03-01

419

40 CFR 721.10199 - Substituted aliphatic amine (generic).  

Code of Federal Regulations, 2010 CFR

40 Protection of Environment 30...Substituted aliphatic amine (generic). 721...Section 721.10199 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...Substituted aliphatic amine (generic)....

2010-07-01

420

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

Microsoft Academic Search

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

C. Q. Ning; Y. Zhou

2002-01-01

421

Theory, manufacturing technology, and properties of powders and fibers  

Microsoft Academic Search

The properties of ferromagnetic powders after reduction annealing are examined. It is shown that magnetite and a destructured\\u000a composite organic coating ensure the resistance of such powders to external effects.

V. V. Nepomnyashchii; T. V. Mosina; A. K. Radchenko; G. Ya. Kalutskii

2007-01-01

422

Rheological and Thermal Debinding Behaviors in Titanium Powder Injection Molding  

NASA Astrophysics Data System (ADS)

Powder injection molding (PIM) is suitable for the fabrication of complex shape titanium and its alloys and has a great potential in many applications. This article deals with the injection molding of hydride-dehydride (HDH) titanium powder, spheroidized HDH titanium powder, and gas-atomized (GA) titanium powder. Rheological and thermal debinding behaviors are compared between feedstocks made from the three powders. Torque and capillary rheometers are used to investigate rheological behavior as it relates to the power-law model of viscosity and moldability index. Thermogravimetric analysis (TGA) was employed to analyze debinding behavior given a master decomposition curve consisting of two sigmoids. Spheroidized HDH Ti powder behaves in a manner similar to GA Ti powder. The analysis of the results in this study indicates the possibility of using a combination of HDH and GA titanium powders for PIM.

Park, Seong-Jin; Wu, Yunxin; Heaney, Donald F.; Zou, Xin; Gai, Guosheng; German, Randall M.

2009-01-01

423

Radio-absorbing properties of nickel-containing schungite powder  

NASA Astrophysics Data System (ADS)

A nickel-containing shungite powder has been synthesized by means of chemical reduction from aqueous solutions. The chemical composition and radio-absorbing properties of this powder have been studied.

Lyn'kov, L. M.; Borbot'ko, T. V.; Krishtopova, E. A.

2009-05-01

424

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

PubMed

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

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

2014-04-01

425

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

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

426

Charging Characteristics of Some Powders Used in Electrostatic Coating  

Microsoft Academic Search

Preliminary studies have been carried out on charging characteristics of two epoxy powders and a polytetrafluoroethylene (PTFE) by measuring charge-to-mass ratios (Q\\/m). The epoxy powders were charged by corona current and the PTFE by triboelectric. The results indicate that for the PTFE powder, the mean Q\\/m is inversely proportional to the particle radius, whereas for epoxy powders the pigmentation and

Sampuran Singh

1981-01-01

427

Substitutions into propositional tautologies Jan Krajcek #+#  

E-print Network

Substitutions into propositional tautologies Jan Krajâ??�Ÿcek #+# Isaac Newton Institute, Cambridge University, Prague. # The paper was written while at the Isaac Newton Institute in Cambridge (Logic

Krajíèek, Jan

428

Processed bovine dentine as a bone substitute  

Microsoft Academic Search

ObjectivesDifferent forms of allogenic dentine have been studied for their potential use as bone substitutes. We report a new method for processing bovine dentine that results in a sterile bioactive material for repair and regeneration of bone.

Keyvan Moharamzadeh; Christine Freeman; Keith Blackwood

2008-01-01

429

24 CFR 221.252 - Substitute mortgagors.  

Code of Federal Regulations, 2010 CFR

...PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES LOW COST AND MODERATE INCOME MORTGAGE INSURANCE-SAVINGS CLAUSE Contract Rights and Obligations-Low Cost Homes § 221.252 Substitute mortgagors. (a)...

2010-04-01

430

24 CFR 221.252 - Substitute mortgagors.  

Code of Federal Regulations, 2013 CFR

...PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES LOW COST AND MODERATE INCOME MORTGAGE INSURANCE-SAVINGS CLAUSE Contract Rights and Obligations-Low Cost Homes § 221.252 Substitute mortgagors. (a)...

2013-04-01

431

24 CFR 221.252 - Substitute mortgagors.  

Code of Federal Regulations, 2011 CFR

...PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES LOW COST AND MODERATE INCOME MORTGAGE INSURANCE-SAVINGS CLAUSE Contract Rights and Obligations-Low Cost Homes § 221.252 Substitute mortgagors. (a)...

2011-04-01

432

24 CFR 221.252 - Substitute mortgagors.  

Code of Federal Regulations, 2012 CFR

...PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES LOW COST AND MODERATE INCOME MORTGAGE INSURANCE-SAVINGS CLAUSE Contract Rights and Obligations-Low Cost Homes § 221.252 Substitute mortgagors. (a)...

2012-04-01

433

24 CFR 221.252 - Substitute mortgagors.  

Code of Federal Regulations, 2014 CFR

...PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES LOW COST AND MODERATE INCOME MORTGAGE INSURANCE-SAVINGS CLAUSE Contract Rights and Obligations-Low Cost Homes § 221.252 Substitute mortgagors. (a)...

2014-04-01

434

Mechanochemical synthesis of nanostructured Sr(Ti{sub 1-x}Fe{sub x})O{sub 3-{delta}} solid-solution powders and their surface photovoltage responses  

SciTech Connect

A series of nanostructure Sr(Ti{sub 1-x}Fe{sub x})O{sub 3-{delta}} (STFx, x=0.4, 0.6, 0.8) solid-solution powders were synthesized by mechanochemical approach milling from the mixture of SrO, Fe{sub 2}O{sub 3} and TiO{sub 2} metal oxides at room temperature. The XRD results revealed that the perovskite STFx nanoparticles were finally formed with few residual {alpha}-Fe{sub 2}O{sub 3} detected dependent on the milling conditions. The structure evolution suggested that the mechanochemical synthesis underwent via a solid-state reaction route to initially form Ti-rich perovskite and then incorporate with the residual {alpha}-Fe{sub 2}O{sub 3} to achieve the estimated composition. The synthesized STF08 powders exhibited the significant Surface Photovoltage (SPV) spectrum response both in UV and in visible-light region with p-type semiconductor behavior. This finding suggested that the synthesized STF nanopowders could potentially utilize more solar spectrum energy effectively for photo-oxidation and photo-catalysis applications. - Graphical abstract: It is demonstrated that Sr(Ti{sub 1-x}Fe{sub x})O{sub 3-{delta}} perovskite nanopowders were successfully synthesized by mechanochemical reaction approach at room temerpature, and the synthesized STF08 powders showed the significant SPV response in UV-VIS region with p-type semiconductor behaviors. Highlights: Black-Right-Pointing-Pointer Sr(Ti{sub 1-x}Fe{sub x})O{sub 3-{delta}} nanopowders synthesized by mechanochemical reaction approach. Black-Right-Pointing-Pointer The reaction process was shorten by introduce high impact energy. Black-Right-Pointing-Pointer Synthesized STF08 powders show the significant SPV response in UV-VIS region. Black-Right-Pointing-Pointer Synthesized STFx powders show p-type semiconductor behaviors.

Chen Xiaofeng [Microelectronics Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Luo Qiong [Microelectronics Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); GlobalFoundries Singapore Pte Ltd, 60 Woodlands Industrial Park D Street 2, Singapore 738406 (Singapore); Han, Mandi [Microelectronics Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Tan, Ooi Kiang, E-mail: eoktan@ntu.edu.sg [Microelectronics Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Tse, Man Siu; Huang Hui [Microelectronics Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)

2012-05-15

435

Nutrient-substituted hydroxyapatites: synthesis and characterization  

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

436

THERMAL CONDUCTIVITY OF POWDER INSULATIONS FOR CRYOGENIC STORAGE  

E-print Network

THERMAL CONDUCTIVITY OF POWDER INSULATIONS FOR CRYOGENIC STORAGE VESSELS Y. S. Choi1 '3 , M. N is measured in steady state, from which the thermal conductivity of powder insulation is calculated and compared with published results. KEYWORDS: Thermal conductivity, Powder insulations, Cryostats PACS:44

Chang, Ho-Myung

437

Oxidation of ultrafine (Si) SiC powders  

Microsoft Academic Search

The increasing usage of ultrafine ceramic powders in the fabrication of highly reliable ceramics results in a growing interest in appropriate processing conditions for these powders. During processing the extremely high surface areas might lead to significant absorbtion of oxygen even at low temperatures. But especially in this temperature regime, oxidation data of powders are rarely available; as far as

R. Vaben; D. Stöver

1994-01-01

438

Critical thicknesses of electrostatic powder coatings from inside  

Microsoft Academic Search

A simple electrostatic model is applied to the charge powder coating of a grounded conductor eventually covered by insulating layers. The electric field inside the powder coating and its evolution during the process are established with also the corresponding evolution in the dielectric layer and some practical consequences are also discussed. The thickness of the charged powder layer is limited

Jacques Cazaux

2007-01-01

439

Cold forging of sintered iron-powder preforms  

Microsoft Academic Search

The paper reports on an investigation into various aspects of cold forging of iron-powder preforms which have been compacted and sintered from atomised iron powder. An upperbound solution is constructed for determining the die pressures developed during the cold forging of iron powder under axisymmetric and plane-strain condition. The results so obtained are discussed critically to illustrate the interaction of

G. Sutradhar; A. K. Jha; S. Kumar

1995-01-01

440

Improved retort for cleaning metal powders with hydrogen  

NASA Technical Reports Server (NTRS)

Improved cleaning retort produces uniform temperature distribution in the heated zone and minimizes hydrogen channeling through the powder bed. Retort can be used for nonmetallic powders, sintering in a reducing atmosphere, and for cleaning powders in reduction atmospheres other than hydrogen.

Arias, A.

1969-01-01

441

Charge decay enhancement in polymer powders using plasma treatment  

Microsoft Academic Search

Slow charge decay characteristics of polymer powders results in occurrence of back corona which adversely affects the integrity of the powder film. The surface property that primarily governs the charge decay characteristics and back corona is the surface resistivity of the powder layer. Since the charge decay through these highly resistive polymers is primarily a surface phenomenon, surface modification was

R. Sharma; R. A. Sims; M. K. Mazumder

2002-01-01

442

Ignition of aluminum powders by electro-static discharge  

Microsoft Academic Search

Metal powder heating and ignition by an electro-static discharge, ESD (or spark) was investigated. For different spark voltages, ESD discharge energies transferred to the powder samples and respective spark radii are evaluated experimentally. Al powder was chosen as a popular metal fuel additive for many energetic formulations, and as a metal, for which spark initiation typically results in ignition of

Ervin Beloni; Edward L. Dreizin

2010-01-01

443

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

PubMed

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

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

2014-01-27

444

Optical properties of undoped and Mg doped CuCrO2 powders synthesized by sol-gel route  

NASA Astrophysics Data System (ADS)

In this work, CuCrO2 was synthesized by sol-gel method using citric acid as a gelling agent. The different parameters like ratio of citric acid to metal ions, calcination temperature, and duration were studied. A green colored powder with particle size around 300 nm was formed at the calcination temperature of 800 °C for four hours duration. The increase in temperature has a profound impact on crystallite size and in turn effected the optical properties. Band gap of the obtained CuCrO2 has varied from 2.3 to 1.7 eV by increasing the temperature from 800 °C to 900 °C. Doping studies were performed by introducing Mg2+ ion to substitute Cr3+ in CuCrO2. X-ray powder diffraction and SEM studies on 2% Mg doped samples indicated a clear formation of side phases. According to the X-ray powder patterns, the reflections from side phases were increasing with the increase in doping concentrations of Mg from 2 to 5%. The side phases were found to be MgCr2O4 spinel and CuO. The band gap has decreased for doped samples in comparison to undoped one. In this paper, sol-gel synthesis and characterization by Xray powder diffraction, SEM studies and UV-Vis-Diffuse Reflectance spectra are presented.

Srinivasan, Radhakrishnan; Bolloju, Satish

2014-01-01

445

Optical properties of undoped and Mg doped CuCrO{sub 2} powders synthesized by sol-gel route  

SciTech Connect

In this work, CuCrO{sub 2} was synthesized by sol-gel method using citric acid as a gelling agent. The different parameters like ratio of citric acid to metal ions, calcination temperature, and duration were studied. A green colored powder with particle size around 300 nm was formed at the calcination temperature of 800 °C for four hours duration. The increase in temperature has a profound impact on crystallite size and in turn effected the optical properties. Band gap of the obtained CuCrO{sub 2} has varied from 2.3 to 1.7 eV by increasing the temperature from 800 °C to 900 °C. Doping studies were performed by introducing Mg{sup 2+} ion to substitute Cr{sup 3+} in CuCrO{sub 2}. X-ray powder diffraction and SEM studies on 2% Mg doped samples indicated a clear formation of side phases. According to the X-ray powder patterns, the reflections from side phases were increasing with the increase in doping concentrations of Mg from 2 to 5%. The side phases were found to be MgCr{sub 2}O{sub 4} spinel and CuO. The band gap has decreased for doped samples in comparison to undoped one. In this paper, sol-gel synthesis and characterization by Xray powder diffraction, SEM studies and UV-Vis-Diffuse Reflectance spectra are presented.

Srinivasan, Radhakrishnan; Bolloju, Satish [Department of Chemistry, BITS Pilani Hyderabad Campus, Jawahar Nagar Village, Shamirpet Mandal, R.R.District, Hyderabad - 500 078 (India)

2014-01-28

446

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

SciTech Connect

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

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

2012-07-15

447

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

NASA Astrophysics Data System (ADS)

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

Su, Xiaocheng; Jiang, Qingguo; Zuo, Anying

2014-10-01

448

EPR Investigation of Irradiated Curry Powder  

SciTech Connect

Gamma-ray irradiated curry powder, a well priced oriental spice was investigated in order to establish the ability of EPR to detect the presence and time stability of free irradiation free-radicals. Accordingly, curry powder aliquots were irradiated with gradually increasing absorbed doses up to 11.3 kGy. The EPR spectra of all irradiated samples show the presence of al last two different species of free radicals, whose concentration increased monotonously with the absorbed doses. A 100 deg. C isothermal annealing of irradiated samples has shown a differential reduction of amplitude of various components of the initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after more than one year storage at room temperature, all of them being very useful in establishing the existence of any previous irradiation treatment.

Duliu, O. G.; Ali, S. I. [University of Bucharest, Department of Atomic and Nuclear Physics, P.O. Box MG-11, 077125 Bucharest (Romania); Georgescu, R. [National Institute for Physics and Nuclear Engineering-Horia Hulubei, P.O. Box MG-6, 077125 Bucharest (Romania)

2007-04-23

449

Dry powder mixes comprising phase change materials  

DOEpatents

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

Salyer, I.O.

1994-02-01

450

Dry powder mixes comprising phase change materials  

DOEpatents

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

Salyer, Ival O. (Dayton, OH)

1994-01-01

451

Dry powder mixes comprising phase change materials  

DOEpatents

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

Salyer, Ival O. (Dayton, OH)

1993-01-01

452

Dry powder mixes comprising phase change materials  

DOEpatents

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

Salyer, Ival O. (Dayton, OH)

1992-01-01

453

Dry powder mixes comprising phase change materials  

DOEpatents

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

Salyer, I.O.

1993-10-19

454

Dry powder mixes comprising phase change materials  

DOEpatents

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

Salyer, Ival O. (Dayton, OH)

1993-01-01

455

Dry powder mixes comprising phase change materials  

DOEpatents

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

Salyer, I.O.

1993-05-18

456

Powder agglomeration in a microgravity environment  

NASA Technical Reports Server (NTRS)

This is the final report for NASA Grant NAG3-755 entitled 'Powder Agglomeration in a Microgravity Environment.' The research program included both two types of numerical models and two types of experiments. The numerical modeling included the use of Monte Carlo type simulations of agglomerate growth including hydrodynamic screening and molecular dynamics type simulations of the rearrangement of particles within an agglomerate under a gravitational field. Experiments included direct observation of the agglomeration of submicron alumina and indirect observation, using small angle light scattering, of the agglomeration of colloidal silica and aluminum monohydroxide. In the former class of experiments, the powders were constrained to move on a two-dimensional surface oriented to minimize the effect of gravity. In the latter, some experiments involved mixture of suspensions containing particles of opposite charge which resulted in agglomeration on a very short time scale relative to settling under gravity.

Cawley, James D.

1994-01-01

457

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

458

Black Holes (With 16 figures)  

Microsoft Academic Search

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

Igor Novikov

1995-01-01

459

Teaching the Black Rhetoric Course.  

ERIC Educational Resources Information Center

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

Cummings, Melbourne S.

460

Quantization of Black Holes  

E-print Network

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

Xiao-Gang He; Bo-Qiang Ma

2010-04-05

461

Black holes. An introduction  

NASA Astrophysics Data System (ADS)

This introduction to the fascinating subject of black holes fills a significant gap in the literature which exists between popular, non-mathematical expositions and advanced textbooks at the research level. It is designed for advanced undergraduates and first year postgraduates as a useful stepping-stone to the advanced literature. The book provides an accessible introduction to the exact solutions of Einstein's vacuum field equations describing spherical and axisymmetric (rotating) black holes. The geometry and physical properties of these spacetimes are explored through the motion of particles and light. The use of different coordinate systems, maximal extensions and Penrose diagrams is explained. The association of the surface area of a black hole with its entropy is discussed and it is shown that with the introduction of quantum mechanics black holes cease to be black and can radiate. This result allows black holes to satisfy the laws of thermodynamics and thus be consistent with the rest of physics.

Raine, Derek; Thomas, Edwin

2005-11-01

462

Extremal hairy black holes  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

463

Powder Handling Device for Analytical Instruments  

NASA Technical Reports Server (NTRS)

Method and system for causing a powder sample in a sample holder to undergo at least one of three motions (vibration, rotation and translation) at a selected motion frequency in order to present several views of an individual grain of the sample. One or more measurements of diffraction, fluorescence, spectroscopic interaction, transmission, absorption and/or reflection can be made on the sample, using light in a selected wavelength region.

Sarrazin, Philippe C. (Inventor); Blake, David F. (Inventor)

2006-01-01

464

Laser cladding using the powder blowing technique  

Microsoft Academic Search

A series of laser-clad samples have been produced using a 5 kW CO2 laser and a powder blowing technique. With the correct conditions, a fused bead of alloy up to 5 mm wide and 1 mm thick can be formed on a surface. A wide variety of combinations of base plate and clad materials have been used, including base plates

J. M. Yellup

1995-01-01

465

77 FR 20987 - Oral Dosage Form New Animal Drugs; Change of Sponsor; Lincomycin Hydrochloride Soluble Powder...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Powder; Penicillin G Potassium in Drinking Water; Tetracycline Powder AGENCY...soluble powders administered in drinking water from Teva Animal Health, Inc...soluble powders administered in drinking water to Quo Vademus, LLC, 277...

2012-04-09

466

Electronic and structural influence of Ni by Pd substitution on the hydrogenation properties of TiNi  

SciTech Connect

In Ti (Ni,Pd) compounds, the hydrogen capacity and the stability of their hydrides decreases when Ni is partially substituted by larger in size Pd atoms. To understand this peculiar behaviour, the crystal structure of TiNi{sub 1-x}Pd{sub x}D{sub y} (x=0.1, 0.3 and 0.5) deuterides and the stability of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been investigated by both neutron diffraction experiments and Density Functional Theory (DFT) calculations. Neutron diffraction shows that at x=0.1 and 0.3, deuterium absorption induces tetragonal distortion in intermetallics sublattice whereas at x=0.5 the cubic symmetry is preserved. The structural properties and the heat of formation of TiNi{sub 1-x}Pd{sub x} (0{<=}x{<=}0.5) intermetallics and their hydrides have been determined by DFT. These results show that Pd substitution increases the stability of the intermetallics and decreases the stability of the hydrides, which confirms the rule of reverse stability. - Graphical abstract: Crystal structure of Ti(Ni,Pd)Hy hydrides in the I4/mmm space group. Highlights: Black-Right-Pointing-Pointer Neutron Diffraction and DFT calculations have been done on TiNi{sub 1-x}Pd{sub x}H{sub y} compounds. Black-Right-Pointing-Pointer Electronic effect of Pd substitution governs the hydrogenation properties in TiNi. Black-Right-Pointing-Pointer The rule of reverse stability in intermetallics/hydrides is observed with Pd substitution. Black-Right-Pointing-Pointer The hydrogen atoms in the I4/mmm structure prefer to occupy the 16n site.

Emami, Hoda; Souques, Raphaeel [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais (France)] [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais (France); Crivello, Jean-Claude, E-mail: crivello@icmpe.cnrs.fr [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais (France)] [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais (France); Cuevas, Fermin [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais (France)] [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais (France)

2013-02-15

467

The Nearest Black Holes  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

468

The Nearest Black Holes  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

469

Perturbations around black holes  

E-print Network

Perturbations around black holes have been an intriguing topic in the last few decades. They are particularly important today, since they relate to the gravitational wave observations which may provide the unique fingerprint of black holes' existence. Besides the astrophysical interest, theoretically perturbations around black holes can be used as testing grounds to examine the proposed AdS/CFT and dS/CFT correspondence.

Bin Wang

2005-11-24

470

Full body powder antichip. Final report  

SciTech Connect

Chipping is the major paint defect listed for automobile customer dissatisfaction. The improved chip resistance and smoother paint surfaces produced by full body powder antichip will result in greater customer satisfaction and greater demand for US-produced automobiles. Powder antichip contains virtually no solvent, thereby reducing the potential VOC emissions from Newark Assembly by more than 90 tons per year as compared to the solvent-borne material presently applied in most full body applications. Since Newark Assembly Plant is in a severe non-attainment air quality area, which must demonstrate a 15% reduction in emissions by 1996, projects such as this are crucial to the longevity of industry in this region. The liquid paint spray systems include incineration of the oven volatile organic compounds (VOC`s) at 1,500 F. Since there are minimal VOC`s in powder coatings and the only possible releases occur only during polymerization, incineration is not required. The associated annual savings resulting from the elimination of the incinerator utilized on the liquid spray system is 1.44 {times} 10{sup 10} BTU`s per unit installed. The annual cost savings is approximately $388 thousand, far below the original estimates.

NONE

1996-04-17

471

Powder processing of hybrid titanium neural electrodes  

NASA Astrophysics Data System (ADS)

A preliminary investigation into the powder production of a novel hybrid titanium neural electrode for EEG is presented. The rheological behavior of titanium powder suspensions using sodium alginate as a dispersant are examined for optimal slip casting conditions. Electrodes were slip cast and sintered at 950°C for 1 hr, 1000°C for 1, 3, and 6 hrs, and 1050°C for 1 hr. Residual porosities from sintering are characterized using Archimedes' technique and image analysis. The pore network is gel impregnated by submerging the electrodes in electrically conductive gel and placing them in a chamber under vacuum. Gel evaporation of the impregnated electrodes is examined. Electrodes are characterized in the dry and gelled states using impedance spectrometry and compared to a standard silver- silver chloride electrode. Power spectral densities for the sensors in the dry and gelled state are also compared. Residual porosities for the sintered specimens were between 50.59% and 44.81%. Gel evaporation tests show most of the impregnated gel evaporating within 20 min of exposure to atmospheric conditions with prolonged evaporation times for electrodes with higher impregnated gel mass. Impedance measurements of the produced electrodes indicate the low impedance of the hybrid electrodes are due to the increased contact area of the porous electrode. Power spectral densities of the titanium electrode behave similar to a standard silver-silver chloride electrode. Tests suggest the powder processed hybrid titanium electrode's performance is better than current dry contact electrodes and comparable to standard gelled silver-silver chloride electrodes.

Lopez, Jose Luis, Jr.

472

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

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

473

Low-Flow-Rate Dry-Powder Feeder  

NASA Technical Reports Server (NTRS)

Apparatus feeds small, precise flow of dry powder through laser beam of optical analyzer measuring patterns of light created by forward scattering (Fraunhofer diffraction) of laser beam from powder particles. From this optical measurement, statistical distribution of sizes of powder particles computed. Rates of flow optimized for measurement of particle-size distributions. Developed for analyzing particle-size distributions of solid-propellant powders. Also adapted to pharmaceutical industry, in manufacture of metal powder, and in other applications where particle-size distributions of materials used to control rates of chemical reactions and/or physical characteristics of processes.

Ramsey, Keith E.

1994-01-01

474

Low-Flow-Rate Dry-Powder Feeder  

NASA Technical Reports Server (NTRS)

Apparatus feeds small, precise flow of dry powder through laser beam of optical analyzer, measuring patterns of light created by forward scattering (Fraunhofer diffraction) of laser beam from powder particles. From measurement, statistical distribution of sizes of powder particles computed. Developed for analyzing particle-size distributions of solid-propellant powders. Also adapted to use in pharmaceutical industry, in manufacture of metal powder, and in other applications in which particle-size distributions of materials used to control rates of chemical reactions and/or physical characteristics of processes.

Ramsey, Keith E.

1994-01-01

475

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

476

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

ERIC Educational Resources Information Center

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

Gantt, Walter N.; Wilson, Robert M.

477

Evidence for black holes.  

PubMed

Black holes are common objects in the universe. Each galaxy contains large numbers-perhaps millions-of stellar-mass black holes, each the remnant of a massive star. In addition, nearly every galaxy contains a supermassive black hole at its center, with a mass ranging from millions to billions of solar masses. This review discusses the demographics of black holes, the ways in which they interact with their environment, factors that may regulate their formation and growth, and progress toward determining whether these objects really warp spacetime as predicted by the general theory of relativity. PMID:12817138

Begelman, Mitchell C

2003-06-20

478

Hubble Hunts Black Holes  

NSDL National Science Digital Library

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

479

Artificial black holes  

E-print Network

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

Gregory Eskin

2011-05-10

480

Black hole Berry phase.  

PubMed

Supersymmetric black holes are characterized by a large number of degenerate ground states. We argue that these black holes, like other quantum mechanical systems with such a degeneracy, are subject to a phenomenon which is called the geometric or Berry's phase: under adiabatic variations of the background values of the supergravity moduli, the quantum microstates of the black hole mix among themselves. We present a simple example where this mixing is exactly computable, that of small supersymmetric black holes in 5 dimensions. PMID:19905501

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

2009-09-25

481

Gravitationless black holes  

NASA Astrophysics Data System (ADS)

A gravitationless black hole model is proposed in accord with a five-dimensional fully covariant Kaluza-Klein (K-K) theory with a scalar field, which unifies the four-dimensional Einsteinian general theory of relativity and Maxwellian electromagnetic theory. It is shown that a dense compact core of a star, when it collapses to a critical density, suddenly turns off or shields its gravitational field. The core, if its mass exceeds an upper limit, directly collapses into a black hole. Otherwise, the extremely large pressure, as the gravity is turned off, immediately stops the collapse and drives the mantle material of supernova moving outward, which leads to an impulsive explosion and forms a neutron star as a remnant. A neutron star can further evolve into a black hole when it accretes enough matter from a companion star such that the total mass exceeds a lower limit. The black hole in the K-K theory is gravitationless at the surface because the scalar field is infinitely strong, which varies the equivalent gravitational constant to zero. In general, a star, at the end of its evolution, is relatively harder to collapse into a gravitationless K-K black hole than a strong gravitational Schwarzschild black hole. This is consistent with the observation of some very massive stars to form neutron stars rather than expected black holes. In addition, the gravitationless K-K black hole should be easier to generate jets than a Schwarzschild black hole.

Zhang, T. X.

2011-08-01

482

Black Hole Thermodynamics  

E-print Network

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

S. Carlip

2014-10-06

483

Black hole thermodynamics  

NASA Astrophysics Data System (ADS)

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

Carlip, S.

2014-10-01

484

Stability of Black Holes and Black Branes  

NASA Astrophysics Data System (ADS)

We establish a new criterion for the dynamical stability of black holes in D ? 4 spacetime dimensions in general relativity with respect to axisymmetric perturbations: Dynamical stability is equivalent to the positivity of the canonical energy, {{E}}, on a subspace, {{T}}, of linearized solutions that have vanishing linearized ADM mass, momentum, and angular momentum at infinity and satisfy certain gauge conditions at the horizon. This is shown by proving that—apart from pure gauge perturbations and perturbations towards other stationary black holes—{{E}} is nondegenerate on {{T}} and that, for axisymmetric perturbations, {{E}} has positive flux properties at both infinity and the horizon. We further show that {{E}} is related to the second order variations of mass, angular momentum, and horizon area by {{E} = ?^2 M -sum_A ?_A ?^2 J_A - ?/8??^2 A}, thereby establishing a close connection between dynamical stability and thermodynamic stability. Thermodynamic instability of a family of black holes need not imply dynamical instability because the perturbations towards other members of the family will not, in general, have vanishing linearized ADM mass and/or angular momentum. However, we prove that for any black brane corresponding to a thermodynamically unstable black hole, sufficiently long wavelength perturbations can be found with {{E} < 0} and vanishing linearized ADM quantities. Thus, all black branes corresponding to thermodynmically unstable black holes are dynamically unstable, as conjectured by Gubser and Mitra. We also prove that positivity of {{E}} on {{T}} is equivalent to the satisfaction of a " local Penrose inequality," thus showing that satisfaction of this local Penrose inequality is necessary and sufficient for dynamical stability. Although we restrict our considerations in this paper to vacuum general relativity, most of the results of this paper are derived using general Lagrangian and Hamiltonian methods and therefore can be straightforwardly generalized to allow for the presence of matter fields and/or to the case of an arbitrary diffeomorphism covariant gravitational action.

Hollands, Stefan; Wald, Robert M.

2013-08-01

485

Preparation and structure of carbonated calcium hydroxyapatite substituted with heavy rare earth ions  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer LnCaHap solid solution particles were prepared using five types of heavy rare earth ions by a precipitation method. Black-Right-Pointing-Pointer The length and the crystallinity of the LnCaHap particles first increased and then decreased with increasing Ln{sup 3+} contents. Black-Right-Pointing-Pointer A series of YCaHap solid solution particles formed with Y/(Y + Ca) = 0-0.10 were investigated using various methods in detail. -- Abstract: Calcium hydroxyapatite (CaHap) particles substituted five types of heavy rare earth ions (Ln: Y{sup 3+}, Gd{sup 3+}, Dy{sup 3+}, Er{sup 3+} and Yb{sup 3+}) were synthesized using a precipitation method and characterized using various means. These Ln ions strongly affected the crystal phases and the structures of the products. With increasing Ln/(Ln + Ca) in the starting solution ([X{sub Ln}]), the length and the crystallinity of the particles first increased and then decreased. The rare earth metal-calcium hydroxyapatite (LnCaHap) solid solution particles were obtained at [X{sub Y}] {<=} 0.10 for substituting Y system and at [X{sub Ln}] {<=} 0.01-0.03 for substituting the other Ln systems. LnPO{sub 4} was mixed with LnCaHap at higher [X{sub Ln}] for all Ln systems. A series of yttrium-calcium hydroxyapatite (YCaHap) solid solutions with [X{sub Y}] = 0-0.10 were investigated using XRD, TEM, ICP-AES, IR and TG-DTA in detail.

Yasukawa, Akemi, E-mail: yasukawa@cc.hirosaki-u.ac.jp [School of Home Economics, Faculty of Education, Hirosaki University, 1-bunkyo, Hirosaki, Aomori 036-8560 (Japan)] [School of Home Economics, Faculty of Education, Hirosaki University, 1-bunkyo, Hirosaki, Aomori 036-8560 (Japan); Kandori, Kazuhiko [School of Chemistry, Osaka University of Education, 4-698-1 Asahigaoka, Kashiwara, Osaka 582-8582 (Japan)] [School of Chemistry, Osaka University of Education, 4-698-1 Asahigaoka, Kashiwara, Osaka 582-8582 (Japan); Tanaka, Hidekazu [Department of Material Science, Faculty of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504 (Japan)] [Department of Material Science, Faculty of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504 (Japan); Gotoh, Keiko [Faculty of Human Life and Environment, Nara Women's University, Kita-uoya-nishi, Nara 630-8506 (Japan)] [Faculty of Human Life and Environment, Nara Women's University, Kita-uoya-nishi, Nara 630-8506 (Japan)

2012-05-15

486

Experimental observations of dry powder inhaler dose fluidisation.  

PubMed

Dry powder inhalers (DPIs) are widely used to deliver respiratory medication as a fine powder. This study investigates the physical mechanism of DPI operation, assessing the effects of geometry, inhalation and powder type on dose fluidisation. Patient inhalation through an idealised DPI was simulated as a linearly increasing pressure drop across three powder dose reservoir geometries permitting an analysis of shear and normal forces on dose evacuation. Pressure drop gradients of 3.3, 10 and 30 kPa s(-1)were applied to four powder types (glass, aluminium, and lactose 6 and 16% fines) and high speed video of each powder dose fluidisation was recorded and quantitatively analysed. Two distinct mechanisms are identified, labelled 'fracture' and 'erosion'. 'Fracture' mode occurs when the initial evacuation occurs in several large agglomerates whilst 'erosion' mode occurs gradually, with successive layers being evacuated by the high speed gas flow at the bed/gas interface. The mechanism depends on the powder type, and is independent of the reservoir geometries or pressure drop gradients tested. Both lactose powders exhibit fracture characteristics, while aluminium and glass powders fluidise as an erosion. Further analysis of the four powder types by an annular shear cell showed that the fluidisation mechanism cannot be predicted using bulk powder properties. PMID:18457930

Tuley, Rob; Shrimpton, John; Jones, Matthew D; Price, Rob; Palmer, Mark; Prime, Dave

2008-06-24

487

Infrared-optical properties of gas-evaporated gold blacks Evidence for anomalous conduction on fractal structures  

Microsoft Academic Search

It is shown that the far-infrared absorption in gas-evaporated gold blacks, which was measured by Harris et al. (1948) exhibits all the features expected for anomalous conduction on fractal structures and therefore constitutes a confirmation of current theory. The frequency-dependent optical conductivity of the gold blacks conforms to the powder law rho varies as exp 0.7 sigma below the relaxation

G. A. Niklasson; C. T. Granqvist

1986-01-01

488

High Resolution Powder Diffraction and Structure Determination  

SciTech Connect

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

Cox, D. E.

1999-04-23

489

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

NASA Astrophysics Data System (ADS)

Y-type polycrystalline hexagonal ferrites Ba2Co2-x-yZnxCuyFe12O22 with 0?x?2 and 0?y?0.8 were prepared by the mixed-oxide route. Single phase Y-type ferrite powders were obtained after calcinations at 1000 °C. Samples sintered at 1200 °C show a permeability that increases with the substitution of Zn for Co and display maximum permeability of ??=35 at 1 MHz for x=1.6 and y=0.4. A resonance frequency fr=500 MHz is observed for Zn-rich ferrites with y=0 and 0.4. The saturation magnetization increases with substitution of Zn for Co. Addition of Bi2O3 shifts the temperature of maximum shrinkage down to T?950 °C. Moreover, an increase of the Cu-concentration further lowers the sintering temperature to T?900 °C, enabling co-firing of the ferrites with Ag metallization for multilayer technologies. However, low-temperature firing reduces the permeability to ??=10 and the resonance frequency is shifted to 1 GHz. Thus substituted hexagonal Y-type ferrites can be used as soft magnetic materials for multilayer inductors for high frequency applications.

Bierlich, S.; Töpfer, J.

2012-05-01

490

Structure-dielectric properties relationships in copper-substituted magnesium ferrites  

SciTech Connect

Graphical abstract: - Highlights: • Synthesis of copper substituted magnesium ferrites materials is reported. • A shift from cubic to tetragonal structure starting with x = 0.84 was observed. • The dielectric properties are influenced by Cu-substitution. - Abstract: Nanocrystalline powders of copper-substituted magnesium ferrites with general formula Mg{sub 1?x}Cu{sub x}Fe{sub 2}O{sub 4} (x = 0.00, 0.17, 0.34, 0.50, 0.67, 0.84, 1.00) were prepared for the first time by sol–gel auto-combustion method, using glycine as fuel agent. Solid phase chemical reactions and the occurrence of spinel structure were monitored by using infrared spectroscopy. X-ray diffraction analysis confirmed the spinel single-phase formation. A shift from cubic structure to tetragonal structure starting with x = 0.84 was also observed. Microstructure of the samples was analyzed by scanning electron microscopy and particle size was estimated from the micrographs. Analysis of dielectric properties revealed very low values of dielectric loss at frequencies over 10 MHz.

Druc, A.C.; Borhan, A.I. [Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, nr. 11, 700506 Iasi (Romania); Nedelcu, G.G.; Leontie, L. [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, nr. 11, 700506 Iasi (Romania); Iordan, A.R. [Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, nr. 11, 700506 Iasi (Romania); Palamaru, M.N., E-mail: palamaru@uaic.ro [Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, nr. 11, 700506 Iasi (Romania)

2013-11-15

491

Open frameworks based on mono-lanthanide-substituted polyoxometaloaluminate building units: Syntheses, structures and properties  

NASA Astrophysics Data System (ADS)

Metal-substituted polyoxometalates are one of the most important research branch in polyoxometalate chemistry and have attached an increasing attention due to not only their intriguing structural diversity but also their special properties applicable to material science. In this paper, A series of novel lanthanide-substituted polyoxometaloaluminates (LSPs), K2(H2O)4Ln(H2O)7[Ln(H2O)3HAlW11O39]·nH2O (Ln=Pr 1, Nd 2, Sm 3, Eu 4, Gd 5, Tb 6; for 1, n=8; for 2,4,5,6, n=7; for 3, n=9), have been hydrothermally made and characterized by infrared (IR) spectra, thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction, respectively. The experimental results indicate these compounds exhibit 3-D frameworks with Gra-type topology constructed by lanthanide cations, mono- lanthanide-substituted [Gd(H2O)3HAlW11O39]5- cluster units and K+ cations. The photoluminescence measurements show that Compounds 2, 4, 6 exhibit the characteristic emission for Nd3+, Eu3+ and Tb3+ cations, respectively. In addition, this series of LSPs show weak second harmonic generation effects and ferroelectric properties. The success in making 1-6 not only provides innovative examples in search of new POM species, but also may open up possibilities for the design of LSP-based materials with related functions.

Li, Xin-Xiong; Cheng, Lin; Yang, Guo-Yu

2013-07-01

492

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

PubMed Central

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

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

2012-01-01

493

Black Hole Mass Estimates and Rapid Growth of Supermassive Black Holes in Luminous z ~ 3.5 Quasars  

NASA Astrophysics Data System (ADS)

We present new near-infrared (IR) observations of the H? ?4861 and Mg II ?2798 lines for 32 luminous quasars with 3.2 < z < 3.9 using the Palomar Hale 200 inch telescope and the Large Binocular Telescope. We find that the Mg II FWHM is well correlated with the H? FWHM, confirming itself as a good substitute for the H? FWHM in the black hole mass estimates. The continuum luminosity at 5100 Å well correlates with the continuum luminosity at 3000 Å and the broad emission line luminosities (H? and Mg II). With simultaneous near-IR spectroscopy of the H? and Mg II lines to exclude the influences of flux variability, we are able to evaluate the reliability of estimating black hole masses based on the Mg II line for high redshift quasars. With the reliable H? line based black hole mass and Eddington ratio estimates, we find that the z ~ 3.5 quasars in our sample have black hole masses 1.90 × 109 M ? <~ M BH <~ 1.37 × 1010 M ?, with a median of ~5.14 × 109 M ? and are accreting at Eddington ratios between 0.30 and 3.05, with a median of ~1.12. Assuming a duty cycle of 1 and a seed black hole mass of 104 M ?, we show that the z ~ 3.5 quasars in this sample can grow to their estimated black hole masses within the age of the universe at their redshifts.

Zuo, Wenwen; Wu, Xue-Bing; Fan, Xiaohui; Green, Richard; Wang, Ran; Bian, Fuyan

2015-02-01

494

Black Hole Mergers Manuela Campanelli  

E-print Network

Department of Physics Duke University Feb 15-17, 2012 #12;Black HolesBlack Hole Mergers Manuela Campanelli Center for Computa6 Antennae galaxies, op6cal, HST · In General Rela6vity (GR), Black Holes (BHs

Wolpert, Robert L

495

String-Corrected Black Holes  

E-print Network

1. Introduction The physics of black holes has revealed manyon the physics of the zero-horizon black holes considered byPhysics, Stanford University, Stanford, CA 94309 Abstract We investigate the geometry of four dimensional black hole

Hubeny, Veronika

2009-01-01

496

Monte Carlo simulation of ion transport of the high strain ionomer with conducting powder electrodes  

NASA Astrophysics Data System (ADS)

The transport of charge due to electric stimulus is the primary mechanism of actuation for a class of polymeric active materials known as ionomeric polymer transducers (IPT). At low frequency, strain response is strongly related to charge accumulation at the electrodes. Experimental results demonstrated using conducting powder, such as single-walled carbon nanotubes (SWNT), polyaniline (PANI) powders, high surface area RuO II, carbon black electrodes etc. as an electrode increases the mechanical deformation of the IPT by increasing the capacitance of the material. In this paper, Monte Carlo simulation of a two-dimensional ion hopping model has been built to describe ion transport in the IPT. The shape of the conducting powder is assumed to be a sphere. A step voltage is applied between the electrodes of the IPT, causing the thermally-activated hopping between multiwell energy structures. Energy barrier height includes three parts: the energy height due to the external electric potential, intrinsic energy, and the energy height due to ion interactions. Finite element method software-ANSYS is employed to calculate the static electric potential distribution inside the material with the powder sphere in varied locations. The interaction between ions and the electrodes including powder electrodes is determined by using the method of images. At each simulation step, the energy of each cation is updated to compute ion hopping rate which directly relates to the probability of an ion moving to its neighboring site. Simulation ends when the current drops to constant zero. Periodic boundary conditions are applied when ions hop in the direction perpendicular to the external electric field. When an ion is moved out of the simulation region, its corresponding periodic replica enters from the opposite side. In the direction of the external electric field, parallel programming is achieved in C augmented with functions that perform message-passing between processors using Message Passing Interface (MPI) standard. The effects of conducting powder size, locations and amount are discussed by studying the stationary charge density plots and ion distribution plots.

He, Xingxi; Leo, Donald J.

2007-04-01

497

Clarifying substituted judgement: the endorsed life approach.  

PubMed

A primary goal of clinical practice is to respect patient autonomy. To promote this goal for patients who have lost the ability to make their own decisions, commentators recommend that surrogates make their treatment decisions based on the substituted judgment standard. This standard is commonly interpreted as directing surrogates to make the decision the patient would have made in the circumstances, if the patient were competent. However, recent commentators have argued that this approach-attempting to make the decision the patient would have made if competent-is theoretically problematic, practically infeasible, and ignores the interests of the patient's family and loved ones. These commentators conclude that the substituted judgment standard should be revised significantly, or abandoned altogether. While this response would avoid the cited problems, it also would require substantial changes to clinical practice and would raise significant problems of its own. The present paper thus considers the possibility that the criticisms do not point to problems with the substituted judgment standard itself; instead, they point to problems with the way it is most commonly interpreted. This analysis suggests that the substituted judgment standard need not be dramatically revised or abandoned. Instead, it should be interpreted in a way that effectively promotes respect for the autonomy of incompetent patients. The 'endorsed life' interpretation described here helps clinicians and surrogates to achieve this important goal. To clarify this approach, we explain how it differs from three other recently proposed alternatives to the standard interpretation of the substituted judgment standard. PMID:25360029

Phillips, John; Wendler, David

2014-10-30

498

Black Hole Shadows of Charged Spinning Black Holes  

E-print Network

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

Rohta Takahashi

2005-05-16

499

The Black College Mystique  

ERIC Educational Resources Information Center

This study compares the culture of black colleges and universities a generation ago with those that exist today, and makes projections into the future, based on a comprehensive review of professional literature and an analysis of the management skills of contemporary black college leaders. The book considers the assets and liabilities of…

Willie, Charles V.; Reddick, Richard J.; Brown, Ronald

2005-01-01

500

Black History Speech  

ERIC Educational Resources Information Center

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

Noldon, Carl

2007-01-01