Rietveld analysis of X-ray powder diffraction patterns as a potential tool for the identification of impact-deformed carbonate rocks

NASA Astrophysics Data System (ADS)

Huson, S. A.; Foit, F. F.; Watkinson, A. J.; Pope, M. C.

2009-12-01

Previous X-ray powder diffraction (XRD) studies revealed that shock deformed carbonates and quartz have broader XRD patterns than those of unshocked samples. Entire XRD patterns, single peak profiles and Rietveld refined parameters of carbonate samples from the Sierra Madera impact crater, west Texas, unshocked equivalent samples from 95 miles north of the crater and the Mission Canyon Formation of southwest Montana and western Wyoming were used to evaluate the use of X-ray powder diffraction as a potential tool for distinguishing impact deformed rocks from unshocked and tectonically deformed rocks. At Sierra Madera dolostone and limestone samples were collected from the crater rim (lower shock intensity) and the central uplift (higher shock intensity). Unshocked equivalent dolostone samples were collected from well cores drilled outside of the impact crater. Carbonate rocks of the Mission Canyon Formation were sampled along a transect across the tectonic front of the Sevier and Laramide orogenic belts. Whereas calcite subjected to significant shock intensities at the Sierra Madera impact crater can be differentiated from tectonically deformed calcite from the Mission Canyon Formation using Rietveld refined peak profiles, weakly shocked calcite from the crater rim appears to be indistinguishable from the tectonically deformed calcite. In contrast, Rietveld analysis readily distinguishes shocked Sierra Madera dolomite from unshocked equivalent dolostone samples from outside the crater and tectonically deformed Mission Canyon Formation dolomite.

Improved camera for better X-ray powder photographs

NASA Technical Reports Server (NTRS)

Parrish, W.; Vajda, I. E.

1969-01-01

Camera obtains powder-type photographs of single crystals or polycrystalline powder specimens. X-ray diffraction photographs of a powder specimen are characterized by improved resolution and greater intensity. A reasonably good powder pattern of small samples can be produced for identification purposes.

Effect of the Chemical State of the Surface on the Relaxation of the Surface Shell Atoms in SiC and GaN Nanocrystals

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H. P.; Janik, J. F.; Palosz, W.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The effect of the chemical state of the surface of nanoparticles on the relaxation in the near-surface layer was examined using the concept of the apparent lattice parameter (alp) determined for different diffraction vectors Q. The apparent lattice parameter is a lattice parameter determined either from an individual Bragg reflection, or from a selected region of the diffraction pattern. At low diffraction vectors the Bragg peak positions are affected mainly by the structure of the near-surface layer, while at high Q-values only the interior of the nano-grain contributes to the diffraction pattern. Following the measurements on raw (as prepared) powders we investigated powders cleaned by annealing at 400C under vacuum, and the same powders wetted with water. Theoretical alp-Q plots showed that the structure of the surface layer depends on the sample treatment. Semi-quantitative analysis based on the comparison of the experimental and theoretical alp-Q plots was performed. Theoretical alp-Q relations were obtained from the diffraction patterns calculated for models of nanocrystals with a strained surface layer using the Debye functions.

New Powder Diffraction File (PDF-4) in relational database format: advantages and data-mining capabilities.

PubMed

Kabekkodu, Soorya N; Faber, John; Fawcett, Tim

2002-06-01

The International Centre for Diffraction Data (ICDD) is responding to the changing needs in powder diffraction and materials analysis by developing the Powder Diffraction File (PDF) in a very flexible relational database (RDB) format. The PDF now contains 136,895 powder diffraction patterns. In this paper, an attempt is made to give an overview of the PDF-4, search/match methods and the advantages of having the PDF-4 in RDB format. Some case studies have been carried out to search for crystallization trends, properties, frequencies of space groups and prototype structures. These studies give a good understanding of the basic structural aspects of classes of compounds present in the database. The present paper also reports data-mining techniques and demonstrates the power of a relational database over the traditional (flat-file) database structures.

Experimental analysis for fabrication of high-aspect-ratio piezoelectric ceramic structure by micro-powder injection molding process

NASA Astrophysics Data System (ADS)

Han, Jun Sae; Gal, Chang Woo; Park, Jae Man; Kim, Jong Hyun; Park, Seong Jin

2018-04-01

Aspect ratio effects in the micro-powder injection molding process were experimentally analyzed for fabrication of high-aspect-ratio piezoelectric ceramic structure. The mechanisms of critical defects have been studied according to individual manufacturing steps. In the molding process, incomplete filling phenomenon determines the critical aspect ratios of a micro pattern. According to mold temperature, an incomplete filling phenomenon has been analyzed with respect to different pattern sizes and aspect ratio. In demolding and drying process, the capillary behavior of sacrificial polymeric mold insert determines the critical aspect ratio of a micro pattern. With respect to pattern dimensions, slumping behavior has been analyzed. Based on our current systems, micro PZT feature has stability when it has lower aspect ratio than 5. Under optimized processing conditions, 20 μm and 40 μm ceramic rod array feature which has 5 of aspect ratio were successfully fabricated by the developed process. Further modification points to fabricate the smaller and higher feature were specifically addressed.

Storage study and quality evaluation of coconut protein powder.

PubMed

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

2013-11-01

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. © 2013 CSIR-Central Food Technological Research Institute.

[METHOD OF INCREASING MICROBIOLOGICAL PURITY OF POWDER FROM COCOA-VELLA].

PubMed

Magomedov, G O; Cheremushkina, L V; Plotnikova, I V

2015-01-01

In the article there is described in detail the characteristic of the product of processing cocoa beans--cocoa-vella, there is presented a comparative analysis of the chemical composition, quality indices, the dispersive pattern, microbiological indices of the powder from the cocoa-vella in comparison to cocoa powder, obtained by traditional technology from the core of the cocoa beans. To improve the microbiological purity of the powder from the cocoa-vella there was suggested to be the modern and environmentally safe manner for the preparation of the powder The use of cocoa-vella disinfecting power by means of the electromagnetic field of ultrahigh frequency (RF EMF) was established to allow to obtain a product that meets the requirements of Technical Regulations of the Customs Union (TRCU 021/2011) on Food Safety. This work is of practical interest, since it helps to improve the safety of the powder from the cocoa-vella, and thus the quality of confectionery and food products based on it, which is relevant in terms of the management of a healthy diet.

Investigation of the solid state properties of amoxicillin trihydrate and the effect of powder pH.

PubMed

Ghassempour, Alireza; Rafati, Hasan; Adlnasab, Laleh; Bashour, Yosef; Ebrahimzadeh, Homeira; Erfan, Mohammad

2007-11-09

The purpose of this research was to investigate some physicochemical and solid-state properties of amoxicillin trihydrate (AMT) with different powder pH within the pharmacopoeia-specified range. AMT batches prepared using Dane salt method with the pH values from 4.39 to 4.97 were subjected to further characterization studies. Optical and scanning electron microscopy showed that different batches of AMT powders were similar in crystal habit, but the length of the crystals increased as the pH increased. Further solid-state investigations using powder x-ray diffraction (PXRD) demonstrated the same PXRD pattern, but the intensity of the peaks raised by the powder pH, indicated increased crystallinity. Differential scanning calorimetry (DSC) studies further confirmed that as the powder pH increased, the crystallinity and, hence, thermal stability of AMT powders increased. Searching for the possible cause of the variations in the solid state properties, HPLC analysis showed that despite possessing the requirements of the United States Pharmacopoeia (USP) for purity/impurity profile, there was a direct relationship between the increase of the powder pH and the purity of AMT, and also decrease in the impurity I (alpha-Hydroxyphenylglycine) concentration in AMT powder. Recrystallization studies confirmed that the powder pH could be controlled by adjusting the pH of the crystallization.

Laser patterning of diamond films

NASA Astrophysics Data System (ADS)

Narayan, J.; Chen, X.

1992-04-01

Selective deposition and fine-scale patterning of hot filament deposited diamond films by the use of pulsed laser irradiation on silicon and copper substrates are reported. The substrates were abraded with diamond and alumina powders before hot-filament chemical vapor deposition. A drastic enhancement in diamond nucleation (using hot-filament chemical vapor deposition) was observed on specimens treated with diamond powder, whereas enhancement on specimens pretreated with alumina powder was relatively insignificant. It is found that the seeding of diamond crystals was substantially reduced by pulsed laser annealing/melting which removes the plastic damage as well as the seed crystals introduced by diamond powder pretreatment. The selective deposition or fine-scale patterning of diamond films was achieved either by a shadow masking or by scanning a focused laser beam to generate desired patterns. The nucleation can also be enhanced by laser deposition of thin films, such as diamond-like carbon and tungsten carbide (WC), and selective deposition and patterning achieved by controlled removal or deposition of the above films.

Application of Powder Diffraction Methods to the Analysis of Short- and Long-Range Atomic Order in Nanocrystalline Diamond and SiC: The Concept of the Apparent Lattice Parameter (alp)

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Gierlotka, S.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H.-P.; Palosz, W.

2003-01-01

Two methods of the analysis of powder diffraction patterns of diamond and SiC nanocrystals are presented: (a) examination of changes of the lattice parameters with diffraction vector Q ('apparent lattice parameter', alp) which refers to Bragg scattering, and (b), examination of changes of inter-atomic distances based on the analysis of the atomic Pair Distribution Function, PDF. Application of these methods was studied based on the theoretical diffraction patterns computed for models of nanocrystals having (i) a perfect crystal lattice, and (ii), a core-shell structure, i.e. constituting a two-phase system. The models are defined by the lattice parameter of the grain core, thickness of the surface shell, and the magnitude and distribution of the strain field in the shell. X-ray and neutron experimental diffraction data of nanocrystalline SiC and diamond powders of the grain diameter from 4 nm up to micrometers were used. The effects of the internal pressure and strain at the grain surface on the structure are discussed based on the experimentally determined dependence of the alp values on the Q-vector, and changes of the interatomic distances with the grain size determined experimentally by the atomic Pair Distribution Function (PDF) analysis. The experimental results lend a strong support to the concept of a two-phase, core and the surface shell structure of nanocrystalline diamond and SiC.

Perylene and Perylene-Derivative Nano-Cocrystals: Preparation and Physicochemical Property

NASA Astrophysics Data System (ADS)

Baba, Koichi; Konta, Sayaka; Oliveira, Daniel; Sugai, Kenji; Onodera, Tsunenobu; Masuhara, Akito; Kasai, Hitoshi; Oikawa, Hidetoshi; Nakanishi, Hachiro

2012-12-01

Organic nano-cocrystals of functional dyes of perylene and a perylene derivative were successfully prepared by the reprecipitation method. The particle sizes, optical properties, and powder X-ray diffraction patterns of nano-cocrystals were evaluated. Typically, the size with size distribution of nano-cocrystals was 55±15 nm when the molar ratio of perylene to the perylene derivative was 50:50. The particular intermolecular electronic interaction between perylene and the perylene derivative in the nano-cocrystal state was observed by absorption and fluorescence spectra measurements. The powder X-ray diffraction pattern analysis confirmed that the structure of nano-cocrystals was different from those prepared from perylene and the perylene derivative. The nano-cocrystal having unique physicochemical properties will be potentially classified as a new type of functional nanomaterial.

Straightforward fabrication of black nano silica dusting powder for latent fingerprint imaging

NASA Astrophysics Data System (ADS)

Komalasari, Isna; Krismastuti, Fransiska Sri Herwahyu; Elishian, Christine; Handayani, Eka Mardika; Nugraha, Willy Cahya; Ketrin, Rosi

2017-11-01

Imaging of latent fingerprint pattern (aka fingermark) is one of the most important and accurate detection methods in forensic investigation because of the characteristic of individual fingerprint. This detection technique relies on the mechanical adherence of fingerprint powder to the moisture and oily component of the skin left on the surface. The particle size of fingerprint powder is one of the critical parameter to obtain excellent fingerprint image. This study develops a simple, cheap and straightforward method to fabricate Nano size black dusting fingerprint powder based on Nano silica and applies the powder to visualize latent fingerprint. The nanostructured silica was prepared from tetraethoxysilane (TEOS) and then modified with Nano carbon, methylene blue and sodium acetate to color the powder. Finally, as a proof-of-principle, the ability of this black Nano silica dusting powder to image latent fingerprint is successfully demonstrated and the results show that this fingerprint powder provides clearer fingerprint pattern compared to the commercial one highlighting the potential application of the nanostructured silica in forensic science.

The spectroscopic detection of exogenous material in fingerprints after development with powders and recovery with adhesive lifters.

PubMed

West, Matthew J; Went, Michael J

2008-01-15

The application of powders to fingerprints has long been established as an effective and reliable method for developing latent fingerprints. The powders adhere to the ridge pattern of the fingerprint only, thus allowing the image to be visualised. Fingerprints developed in situ at a crime scene routinely undergo lifting with specialist tapes to facilitate subsequent laboratory analysis. As with all recovered evidence these samples would be stored in evidence bags to allow secure transit from the scene to the laboratory and also to preserve the chain of evidence. In this paper, the application of Raman spectroscopy for the analysis of exogenous material in latent fingerprints is reported for contaminated fingerprints that had been treated with powders and also subsequently lifted with adhesive tapes. A selection of over the counter (OTC) analgesics were used as samples for the analysis and contaminated fingerprints were deposited on clean glass slides. The application of aluminium or iron based powders to contaminated fingerprints did not interfere with the Raman spectra obtained for the contaminants. In most cases background fluorescence attributed to the sebaceous content of the latent fingerprint was reduced by the application of the powder thus reducing spectral interference. Contaminated fingerprints developed with powders and then lifted with lifting tapes were also examined. The combination of these two techniques did not interfere with the successful analysis of exogenous contaminants by Raman spectroscopy. The lifting process was repeated using hinge lifters. As the hinge lifters exhibited strong Raman bands the spectroscopic analysis was more complex and an increase in the number of exposures to the detector allowed for improved clarification. Raman spectra of developed and lifted fingerprints recorded through evidence bags were obtained and it was found that the detection process was not compromised in any way. Although the application of powders did not interfere with the detection process the time taken to locate the contaminant was increased due to the physical presence of more material within the fingerprint. The presence of interfering Raman bands from lifting tapes is another potential complication. This, however, could be removed by spectral subtraction or by the choice of lifting tapes that have only weak Raman bands.

A structural investigation into the compaction behavior of pharmaceutical composites using powder X-ray diffraction and total scattering analysis.

PubMed

Moore, Michael D; Steinbach, Alison M; Buckner, Ira S; Wildfong, Peter L D

2009-11-01

To use advanced powder X-ray diffraction (PXRD) to characterize the structure of anhydrous theophylline following compaction, alone, and as part of a binary mixture with either alpha-lactose monohydrate or microcrystalline cellulose. Compacts formed from (1) pure theophylline and (2) each type of binary mixture were analyzed intact using PXRD. A novel mathematical technique was used to accurately separate multi-component diffraction patterns. The pair distribution function (PDF) of isolated theophylline diffraction data was employed to assess structural differences induced by consolidation and evaluated by principal components analysis (PCA). Changes induced in PXRD patterns by increasing compaction pressure were amplified by the PDF. Simulated data suggest PDF dampening is attributable to molecular deviations from average crystalline position. Samples compacted at different pressures were identified and differentiated using PCA. Samples compacted at common pressures exhibited similar inter-atomic correlations, where excipient concentration factored in the analyses involving lactose. Practical real-space structural analysis of PXRD data by PDF was accomplished for intact, compacted crystalline drug with and without excipient. PCA was used to compare multiple PDFs and successfully differentiated pattern changes consistent with compaction-induced disordering of theophylline as a single component and in the presence of another material.

Influence of ammonium hydroxide solution on LiMn2O4 nanostructures prepared by modified chemical bath method

NASA Astrophysics Data System (ADS)

Koao, Lehlohonolo F.; Motloung, Setumo V.; Motaung, Tshwafo E.; Kebede, Mesfin A.

2018-04-01

LiMn2O4 (LMO) powders were prepared by modified chemical bath deposition (CBD) method by varying ammonium hydroxide solution (AHS). The volume of the AHS was varied from 5 to 120 mL in order to determine the optimum volume that is needed for preparation of LMO powders. The effect of AHS volume on the structure, morphology, and electrochemical properties of LMO powders was investigated. The X-ray diffraction (XRD) patterns of the LMO powders correspond to the cubic spinel LMO phase. It was found that the XRD peaks increased in intensity with increasing volume of the AHS up to 20 mL. The estimated average grain sizes calculated using the XRD patterns were found to be in the order of 66 ± 1 nm. It was observed that the estimated average grain sizes increased up to 20 mL of AHS. The scanning electron microscopy (SEM) results revealed that the AHS volume does not influence the surface morphology of the prepared nano-powders. Elemental energy dispersive (EDS) analysis mapping conducted on the samples revealed homogeneous distribution of Mn and O for the sample synthesized with 120 mL of AHS. The UV-Vis spectra showed a red shift with an increase in AHS up 20 mL. The cyclic voltammetry and galvanostatic charge/discharge cycle testing confirmed that 20 mL of AHS has superior lithium ion kinetics and electrochemical performance.

Synthesis of cerium oxide (CeO 2) by co-precipitation for application as a reference material for X-ray powder diffraction peak widths

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Lima Batista, Anderson Márcio; Miranda, Marcus Aurélio Ribeiro; Martins, Fátima Itana Chaves Custódio

Several methods can be used to obtain, from powder diffraction patterns, crystallite size and lattice strain of polycrystalline samples. Some examples are the Scherrer equation, Williamson–Hall plots, Warren/Averbach Fourier decomposition, Whole Powder Pattern Modeling, and Debye function analysis. To apply some of these methods, it is necessary to remove the contribution of the instrument to the widths of the diffraction peaks. Nowadays, one of the main samples used for this purpose is the LaB6 SRM660b commercialized by the National Institute of Standard Technology; the width of the diffraction peak of this sample is caused only by the instrumental apparatus. However,more » this sample can be expensive for researchers in developing countries. In this work, the authors present a simple route to obtain micron-sized polycrystalline CeO 2that have a full width at half maximum comparable with the SRM660b and therefore it can be used to remove instrumental broadening.« less

Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl(6) and other alloys are twinned cubic crystals.

PubMed

Pauling, L

1987-06-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl(6) and Mg(32)(Al,Zn)(49) and the neutron powder diffraction pattern of MnAl(6) are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 A (x-ray) and 23.416 A (neutron) for MnAl(6) and 24.313 A (x-ray) for Mg(32)(Al,Zn)(49).

Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl6 and other alloys are twinned cubic crystals

PubMed Central

Pauling, Linus

1987-01-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl6 and Mg32(Al,Zn)49 and the neutron powder diffraction pattern of MnAl6 are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 Å (x-ray) and 23.416 Å (neutron) for MnAl6 and 24.313 Å (x-ray) for Mg32(Al,Zn)49. PMID:16593841

The development of a new method to detect the adulteration of commercial aloe gel powders.

PubMed

Kim, K H; Lee, J G; Kim, D G; Kim, M K; Park, J H; Shin, Y G; Lee, S K; Jo, T H; Oh, S T

1998-10-01

Simple and accurate methods to detect the adulteration of commercial aloe gel powder were developed. Crude polysaccharide in aloe gel powder was isolated by precipitating with excess ethyl alcohol and total hexose in isolated polysaccharide was determined by Dubois assay. After hydrolysis of non-dialysable polysaccharides, resultant free sugar was determined by gas chromatography for sugar recognition and ash contents was considered simultaneously. In some products, the content of ash was very low while the content of total hexose was very high. And polysaccharides of these products revealed typical dextran pattern, therefore, these products could be identified that adulterated with commercial maltodextrin. The content of maltodextrin in adulterated product was determined by HPLC and TLC analysis which could be adopted as a part of a certification process.

Testing the limits of sensitivity in a solid-state structural investigation by combined X-ray powder diffraction, solid-state NMR, and molecular modelling.

PubMed

Filip, Xenia; Borodi, Gheorghe; Filip, Claudiu

2011-10-28

A solid state structural investigation of ethoxzolamide is performed on microcrystalline powder by using a multi-technique approach that combines X-ray powder diffraction (XRPD) data analysis based on direct space methods with information from (13)C((15)N) solid-state Nuclear Magnetic Resonance (SS-NMR) and molecular modeling. Quantum chemical computations of the crystal were employed for geometry optimization and chemical shift calculations based on the Gauge Including Projector Augmented-Wave (GIPAW) method, whereas a systematic search in the conformational space was performed on the isolated molecule using a molecular mechanics (MM) approach. The applied methodology proved useful for: (i) removing ambiguities in the XRPD crystal structure determination process and further refining the derived structure solutions, and (ii) getting important insights into the relationship between the complex network of non-covalent interactions and the induced supra-molecular architectures/crystal packing patterns. It was found that ethoxzolamide provides an ideal case study for testing the accuracy with which this methodology allows to distinguish between various structural features emerging from the analysis of the powder diffraction data. This journal is © the Owner Societies 2011

Driving forces of redistribution of elements during quasicrystalline phase formation under heating of mechanically alloyed Al65Cu23Fe12 powder

NASA Astrophysics Data System (ADS)

Tcherdyntsev, V. V.; Kaloshkin, S. D.; Shelekhov, E. V.; Principi, G.; Rodin, A. O.

2008-02-01

Al65Cu23Fe12 alloys were prepared by ball milling of the elemental powders mixture. Phase and structural transformations at heating of as-milled powders were investigated by X-ray diffraction analysis. Precision analysis of Mössbauer spectra was performed to check the adequacy of the fitting of X-ray diffraction patterns. The results were compared with the data of differential scanning and solution calorimetry, as well as with the thermodynamic literature data, in order to estimate the driving forces of redistribution of elements that preceded the formation of single-phase quasicrystalline structure. The heat of elements mixing, which is positive for Cu-Fe system and negative for Al-Fe and Al-Cu systems, was supposed to be a decisive factor for phase transformations during heating of the alloy. The correlation between sequence of phase transformations during heating and the thermodynamic data was discussed and the scheme describing phase transformations observed was proposed.

Microwave assisted synthesis and characterization of barium titanate nanoparticles for multi layered ceramic capacitor applications.

PubMed

Thirumalai, Sundararajan; Shanmugavel, Balasivanandha Prabu

2011-01-01

Barium titanate is a common ferroelectric electro-ceramic material having high dielectric constant, with photorefractive effect and piezoelectric properties. In this research work, nano-scale barium titanate powders were synthesized by microwave assisted mechano-chemical route. Suitable precursors were ball milled for 20 hours. TGA studies were performed to study the thermal stability of the powders. The powders were characterized by XRD, SEM and EDX Analysis. Microwave and Conventional heating were performed at 1000 degrees C. The overall heating schedule was reduced by 8 hours in microwave heating thereby reducing the energy and time requirement. The nano-scale, impurity-free and defect-free microstructure was clearly evident from the SEM micrograph and EDX patterns. LCR meter was used to measure the dielectric constant and dielectric loss values at various frequencies. Microwave heated powders showed superior dielectric constant value with low dielectric loss which is highly essential for the fabrication of Multi Layered Ceramic Capacitors.

High purity Fe3O4 from Local Iron Sand Extraction

NASA Astrophysics Data System (ADS)

Gunanto, Y. E.; Izaak, M. P.; Jobiliong, E.; Cahyadi, L.; Adi, W. A.

2018-04-01

Indonesia has a long coastline and is rich with iron sand. The iron sand is generally rich in various elements such as iron and titanium. One of the products processing of the iron sand mineral is iron (II) (III) oxide (magnetite Fe3O4). The stages of purification process to extracting magnetite phase and discarding the other phases has been performed. Magnetite phase analysis of ironsand extraction retrieved from Indonesia have been investigated. The result of analysis element of iron sand shows that it consists of majority Fe around 65 wt%. However, there are still 17 impurities such as Ti, Al, Ce, Co, Cr, Eu, La, Mg, Mn, Na, Sc, Sm, Th, V, Yb, and Zn. After extraction process, Fe element content increases up to 94%. The iron sand powder after milling for 10 hours and separating using a magnetic separator, the iron sand powders are dissolved in acid chloride solution to form a solution of iron chloride, and this solution is sprinkled with sodium hydroxide to obtain fine powders of Fe3O4. The fine powders which formed were washed with de-mineralization water. The X-ray diffraction pattern shows that the fine powders have a single phase of Fe3O4. The analysis result shows that the sample has the chemical formula: Fe3O4 with a cubic crystal system, space group: Fd-3m and lattice parameters: a = b = c = 8.3681 (1) Å, α = β = γ = 90°. The microstructure analysis shows that the particle of Fe3O4 homogeneously shaped like spherical. The magnetic properties using vibrating sample magnetometer shows that Fe3O4 obtained have ferromagnetic behavior with soft magnetic characteristics. We concluded that this purification of iron sand had been successfully performed to obtain fine powders of Fe3O4 with high purity.

Nanoscale contact resistance of V2O5 xerogel films developed by nanostructured powder

NASA Astrophysics Data System (ADS)

Bera, Biswajit; Sekhar Das, Pradip; Bhattacharya, Manjima; Ghosh, Swapankumar; Mukhopadhyay, Anoop Kumar; Dey, Arjun

2016-03-01

Here we report the synthesis of V2O5 nanostructures by a fast, simple, cost-effective, low-temperature chemical process; followed by the deposition of V2O5 xerogel thin films on a glass substrate by a sol-gel route. Phase analysis, phase transition, microstructural and electronic characterization studies are carried out by x-ray diffraction, texture coefficient analysis, field emission scanning electron microscopy, transmission electron microscopy (TEM), related selected area electron diffraction pattern (SAED) analysis, Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis, differential scanning calorimetry, and x-ray photoelectron spectroscopy techniques. Confirmatory TEM and SAED data analysis prove further that in this polycrystalline powder there is a unique localized existence of purely single crystalline V2O5 powder with a preferred orientation in the (0 1 0) direction. The most interesting result obtained in the present work is that the xerogel thin films exhibit an inherent capability to enhance the intrinsic resistance against contact induced deformations as more external load is applied during the nanoindentation experiments. In addition, both the nanohardness and Young’s modulus of the films are found to be insensitive to load variations (e.g. 1 to 7 mN). These results are explained in terms of microstructural parameters, e.g. porosity and structural configuration.

[Studies of pattern recognition of fingerprint profile of cattle bile powder and determination of multi-component in it].

PubMed

Shi, Yan; Zheng, Tian-Jiao; Wei, Feng; Lin, Rui-Chao; Ma, Shuang-Cheng

2016-07-01

An HPLC-ELSD method with good specificity and good accuracy was used for the studies of fingerprint and quantification of multi-components for cattle bile powder. The chromatographic analysis was carried out on a Phenomenex Gemini C₁₈ column (4.6 mm×250 mm, 5 μm) with a column temperature of 40 ℃ and a liquid flow-rate of 1.0 mL•min⁻¹ using 10 mmol ammonium acetate solution and acetonitrile as the mobile phase with a linear gradient. An ELSD was used with a nitrogen flow-rate of 2.8 L•h⁻¹, at a drift tube temperature of 110 ℃. The average contents of glycocholic acid, glycodeoxycholic acid, taurocholic acid, taurodeoxycholic acid were (25.2±17.0)%, (4.1±3.4)%, (24.5±20.0)% and (5.2±3.8)% respectively, and the total content of the four bile acids was (59.0±26.0)%. Beyond that, the preprocessing and pattern recognition analysis of the chromatographic fingerprints of samples were applied with chemometric method. The results of this chemometric analysis indicated that the samples from market and self-made samples were different signally, and four regions were noteworthy due to their great impact with poor chromatographic signal. All in one, because this HPLC-ELSD method was simple and accurate, it was suitable for the quality assessment and quality control of cattle bile powder and could be the technological base for its standard perfection. Copyright© by the Chinese Pharmaceutical Association.

Synthesis of fluorapatite–hydroxyapatite nanoparticles and toxicity investigations

PubMed Central

Montazeri, N; Jahandideh, R; Biazar, Esmaeil

2011-01-01

In this study, calcium phosphate nanoparticles with two phases, fluorapatite (FA; Ca10(PO4)6F2) and hydroxyapatite (HA; Ca10(PO4)6(OH)2), were prepared using the solgel method. Ethyl phosphate, hydrated calcium nitrate, and ammonium fluoride were used, respectively, as P, Ca, and F precursors with a Ca:P ratio of 1:72. Powders obtained from the sol-gel process were studied after they were dried at 80°C and heat treated at 550°C. The degree of crystallinity, particle and crystallite size, powder morphology, chemical structure, and phase analysis were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Zetasizer experiments. The results of XRD analysis and FTIR showed the presence of hydroxyapatite and fluorapatite phases. The sizes of the crystallites estimated from XRD patterns using the Scherrer equation and the crystallinity of the hydroxyapatite phase were about 20 nm and 70%, respectively. Transmission electron microscope and SEM images and Zetasizer experiments showed an average size of 100 nm. The in vitro behavior of powder was investigated with mouse fibroblast cells. The results of these experiments indicated that the powders were biocompatibile and would not cause toxic reactions. These compounds could be applied for hard-tissue engineering. PMID:21499417

Laser Printing of Superhydrophobic Patterns from Mixtures of Hydrophobic Silica Nanoparticles and Toner Powder.

PubMed

Ngo, Chi-Vinh; Chun, Doo-Man

2016-11-08

In this work, a new and facile dry printing method was developed for the direct fabrication of superhydrophobic patterns based on silica nanoparticles. Mixtures of hydrophobic fumed silica nanoparticles and toner powder were printed on paper and polymer sheets using a commercial laser printer to produce the superhydrophobic patterns. The mixing ratio of the toner powder (for the laser printer) to hydrophobic silica was also investigated to optimize both the printing quality and the superhydrophobicity of the printed areas. The proper mixing ratio was then used to print various superhydrophobic patterns, including triangular, square, circular, and complex arrangements, to demonstrate that superhydrophobic surfaces with different patterns can be fabricated in a few seconds without any post-processing. The superhydrophobicity of each sample was evaluated by contact angle measurements, and all printed areas showed contact angles greater than 150°. The research described here opens the possibility of rapid production of superhydrophobic surfaces with various patterns. Ultimately, the obtained findings may have a significant impact on applications related to self-cleaning, control of water geometry and position, fluid mixing and fluid transport.

Laser Printing of Superhydrophobic Patterns from Mixtures of Hydrophobic Silica Nanoparticles and Toner Powder

PubMed Central

Ngo, Chi-Vinh; Chun, Doo-Man

2016-01-01

In this work, a new and facile dry printing method was developed for the direct fabrication of superhydrophobic patterns based on silica nanoparticles. Mixtures of hydrophobic fumed silica nanoparticles and toner powder were printed on paper and polymer sheets using a commercial laser printer to produce the superhydrophobic patterns. The mixing ratio of the toner powder (for the laser printer) to hydrophobic silica was also investigated to optimize both the printing quality and the superhydrophobicity of the printed areas. The proper mixing ratio was then used to print various superhydrophobic patterns, including triangular, square, circular, and complex arrangements, to demonstrate that superhydrophobic surfaces with different patterns can be fabricated in a few seconds without any post-processing. The superhydrophobicity of each sample was evaluated by contact angle measurements, and all printed areas showed contact angles greater than 150°. The research described here opens the possibility of rapid production of superhydrophobic surfaces with various patterns. Ultimately, the obtained findings may have a significant impact on applications related to self-cleaning, control of water geometry and position, fluid mixing and fluid transport. PMID:27824132

Vibrational spectra, powder X-ray diffractions and physical properties of cyanide complexes with 1-ethylimidazole

NASA Astrophysics Data System (ADS)

Kürkçüoğlu, Güneş Süheyla; Kiraz, Fulya Çetinkaya; Sayın, Elvan

2015-10-01

The heteronuclear tetracyanonickelate(II) complexes of the type [M(etim)Ni(CN)4]n (hereafter, abbreviated as M-Ni-etim, M = Mn(II), Fe(II) or Co(II); etim = 1-ethylimidazole, C5H8N2) were prepared in powder form and characterized by FT-IR and Raman spectroscopy, powder X-ray diffraction (PXRD), thermal (TG; DTG and DTA), and elemental analysis techniques. The structures of these complexes were elucidated using vibrational spectra and powder X-ray diffraction patterns with the peak assignment to provide a better understanding of the structures. It is shown that the spectra are consistent with a proposed crystal structure for these compounds derived from powder X-ray diffraction measurements. Vibrational spectra of the complexes were presented and discussed with respect to the internal modes of both the etim and the cyanide ligands. The C, H and N analyses were carried out for all the complexes. Thermal behaviors of these complexes were followed using TG, DTG and DTA curves in the temperature range 30-700 °C in the static air atmosphere. The FT-IR, Raman spectra, thermal and powder X-ray analyses revealed no significant differences between the single crystal and powder forms. Additionally, electrical and magnetic properties of the complexes were investigated. The FT-IR and Raman spectroscopy, PXRD, thermal and elemental analyses results propose that these complexes are similar in structure to the Hofmann-type complexes.

The Powder Diffraction File: Past, Present, and Future

PubMed Central

Smith, Deane K.; Jenkins, Ron

1996-01-01

The Powder Diffraction file has been the primary reference for Powder Diffraction Data for more than half a century. The file is a collection of about 65 000 reduced powder patterns stored as sets of d/I data along with the appropriate crystallographic, physical and experimental information. This paper reviews the development and growth of the PDF and discusses the role of the ICDD in the maintenance and dissemination of the file. PMID:27805163

Evaluation of biochar powder on oxygen supply efficiency and global warming potential during mainstream large-scale aerobic composting.

PubMed

He, Xueqin; Chen, Longjian; Han, Lujia; Liu, Ning; Cui, Ruxiu; Yin, Hongjie; Huang, Guangqun

2017-12-01

This study investigated the effects of biochar powder on oxygen supply efficiency and global warming potential (GWP) in the large-scale aerobic composting pattern which includes cyclical forced-turning with aeration at the bottom of composting tanks in China. A 55-day large-scale aerobic composting experiment was conducted in two different groups without and with 10% biochar powder addition (by weight). The results show that biochar powder improves the holding ability of oxygen, and the duration time (O 2 >5%) is around 80%. The composting process with above pattern significantly reduce CH 4 and N 2 O emissions compared to the static or turning-only styles. Considering the average GWP of the BC group was 19.82% lower than that of the CK group, it suggests that rational addition of biochar powder has the potential to reduce the energy consumption of turning, improve effectiveness of the oxygen supply, and reduce comprehensive greenhouse effects. Copyright © 2017. Published by Elsevier Ltd.

Bile acid patterns in commercially available oxgall powders used for the evaluation of the bile tolerance ability of potential probiotics

PubMed Central

Hu, Peng-Li; Yuan, Ya-Hong; Yue, Tian-Li

2018-01-01

This study aimed to analyze the bile acid patterns in commercially available oxgall powders used for evaluation of the bile tolerance ability of probiotic bacteria. Qxgall powders purchased from Sigma-Aldrich, Oxoid and BD Difco were dissolved in distilled water, and analyzed. Conjugated bile acids were profiled by ion-pair high-performance liquid chromatography (HPLC), free bile acids were detected as their p-bromophenacyl ester derivatives using reversed-phase HPLC after extraction with acetic ether, and total bile acids were analyzed by enzymatic-colorimetric assay. The results showed that 9 individual bile acids (i.e., taurocholic acid, glycocholic acid, taurodeoxycholic acid, glycodeoxycholic acid, taurochenodeoxycholic acid, glycochenodeoxycholic acid, cholic acid, chenodeoxycholic acid, deoxycholic acid) were present in each of the oxgall powders tested. The content of total bile acid among the three oxgall powders was similar; however, the relative contents of the individual bile acids among these oxgall powders were significantly different (P < 0.001). The oxgall powder from Sigma-Aldrich was closer to human bile in the ratios of glycine-conjugated bile acids to taurine-conjugated bile acids, dihydroxy bile acids to trihydroxy bile acids, and free bile acids to conjugated bile acids than the other powders were. It was concluded that the oxgall powder from Sigma-Aldrich should be used instead of those from Oxoid and BD Difco to evaluate the bile tolerance ability of probiotic bacteria as human bile model. PMID:29494656

Structure investigations of ferromagnetic Co-Ni-Al alloys obtained by powder metallurgy.

PubMed

Maziarz, W; Dutkiewicz, J; Lityńska-Dobrzyńska, L; Santamarta, R; Cesari, E

2010-03-01

Elemental powders of Co, Ni and Al in the proper amounts to obtain Co(35)Ni(40)Al(25) and Co(40)Ni(35)Al(25) nominal compositions were ball milled in a high-energy mill for 80 h. After 40 h of milling, the formation of a Co (Ni, Al) solid solution with f.c.c. structure was verified by a change of the original lattice parameter and crystallite size. Analytical transmission electron microscopy observations and X-ray diffraction measurements of the final Co (Ni, Al) solid solution showed that the crystallite size scattered from 4 to 8 nm and lattice parameter a = 0.36086 nm. The chemical EDS point analysis of the milled powder particles allowed the calculation of the e/a ratio and revealed a high degree of chemical homogeneity of the powders. Hot pressing in vacuum of the milled powders resulted in obtaining compacts with a density of about 70% of the theoretical one. An additional heat treatment increased the density and induced the martensitic transformation in a parent phase. Selected area diffraction patterns and dark field images obtained from the heat-treated sample revealed small grains around 300 nm in diameter consisting mainly of the ordered gamma phase (gamma'), often appearing as twins, and a small amount of the L1(0) ordered martensite.

Eu2+,Dy3+ codoped SrAl2O4 nanocrystalline phosphor for latent fingerprint detection in forensic applications

NASA Astrophysics Data System (ADS)

Sharma, Vishal; Das, Amrita; Kumar, Vinay

2016-01-01

In this work, europium and dysprosium doped strontium aluminate (SrAl2O4:Eu2+,Dy3+) nanophosphor is synthesized and its novel application for the detection of latent fingerprints on various contact surfaces is reported. The SrAl2O4:Eu2+,Dy3+ is synthesized using a combustion method and shows long-lasting afterglow luminescence. The powder particles are characterized using field emission scanning electron microscopy (FE-SEM), SEM-energy dispersive x-ray analysis, x-ray diffraction and photoluminescence spectrophotometry. The FE-SEM image analysis reveals that the nanoparticles are mostly 8-15 nm in size with an irregular spherical shape. This nano-structured powder was applied to fresh and aged fingerprints deposited on porous, semi-porous and non-porous contact surfaces, such as ordinary colored paper, glossy paper, glass, aluminum foil, a yellow foil chocolate wrapper, a soft drink can, a PET bottle, a compact disc and a computer mouse. The results are reproducible and show great sensitivity and high contrast in the developed fingermark regions on these surfaces. These nanophosphor particles also show a strong and long-lasting afterglow property, making them a suitable candidate for use as a fingerprint developing agent on luminescent and highly patterned surfaces. These kinds of powders have shown that they can remove the interference from background luminescence, which is not possible using ordinary luminescent fingerprinting powders.

Spectroscopic detection of exogenous materials in latent fingerprints treated with powders and lifted off with adhesive tapes.

PubMed

Banas, A; Banas, K; Breese, M B H; Loke, J; Lim, S K

2014-07-01

Fingerprint evidence offers great value to criminal investigations since it is an internationally recognized and established means of human identification. With recent advances in modern technology, scientists have started analyzing not only the ridge patterns of fingerprints but also substances which can be found within them. The aim of this work was to determine whether Fourier transform infrared (FTIR) spectromicroscopy could be used to detect contamination in a fingerprint which was dusted with powder (a technique already recognized as an effective and reliable method for developing latent fingerprints) and subsequently lifted off with adhesive tape. Explosive materials (pentaerythritol tetranitrate, C-4, TNT) and noncontrolled substances (sugar, aspirin) were used to prepare contaminated fingerprints on various substrates. Freshly deposited fingermarks with powders which were lifted off with adhesive tapes (provided by Singapore Police Force) were analyzed using a Bruker Hyperion 2000 microscope at the ISMI beamline (Singapore Synchrotron Light Source) with an attenuated total reflection objective. FTIR spectroscopy is a nondestructive technique which requires almost no sample preparation. Further, the fingerprint under analysis remains in pristine condition, allowing subsequent analysis if necessary. All analyzed substances were successfully distinguished using their FTIR spectra in powdered and lifted fingerprints. This method has the potential to significantly impact forensic science by greatly enhancing the information that can be obtained from the study of fingerprints.

Nasal deposition and clearance in man: comparison of a bidirectional powder device and a traditional liquid spray pump.

PubMed

Djupesland, Per Gisle; Skretting, Arne

2012-10-01

Delivery of powder formulations to the nose is an attractive alternative for many drugs and vaccines. This study compared the regional nasal deposition and clearance patterns of lactose powder delivered by the OptiNose powder device (Opt-Powder; OptiNose US Inc., Yardley, PA, USA) to that of liquid aerosol administered via a traditional hand-actuated liquid spray pump (Rexam SP270, Rexam Pharma, France). The study was an open-label, crossover design in seven healthy subjects (five females, two males). The regional nasal deposition and clearance patterns of the Opt-Powder device were compared to a traditional liquid spray pump by dynamic gamma camera imaging after administration of either (99m)Tc-labeled lactose powder or liquid (99m)Tc- diethelyne triamine pentaacetic acid-aerosol. The gamma camera images were scaled and aligned with sagittal magnetic resonance images to identify nasal regions. Possible deposition of radiolabeled material in the lungs following both methods of delivery was also evaluated. Both powder and spray were distributed to all of the nasal regions. The Opt-Powder device, however, achieved significantly larger initial deposition in the upper and middle posterior regions of the nose than spray (upper posterior region; Opt-Powder 18.3% ± 11.5 vs. Spray 2.4% ± 1.8, p<0.02; sum of upper and middle posterior regions; Opt-Powder 53.5% ± 18.5 vs. Spray 15.7% ± 13.8, p<0.02). The summed initial deposition to the lower anterior and posterior regions for spray was three times higher compared to Opt-Powder (Opt-Powder 17.4% ± 24.5 vs. Spray 59.4% ± 18.2, p<0.04). OptiNose powder delivery resulted in more rapid overall nasal clearance. No lung deposition was observed. The initial deposition following powder delivery was significantly larger in the ciliated mucosa of the upper and posterior nasal regions, whereas less was deposited in the lower regions. Overall nasal clearance of powder was slower initially, but due to retention in anterior nonciliated regions the overall nasal clearance after spray was slower.

Gunshot residue patterns on skin in angled contact and near contact gunshot wounds.

PubMed

Plattner, T; Kneubuehl, B; Thali, M; Zollinger, U

2003-12-17

The goal of this study was the reproduction of shape and pattern of gunshot residues in near contact and contact gunshot wounds by a series of experimental gunshots on a skin and soft tissue model. The aim was to investigate the shape and direction of soot deposits with regard to the muzzle according to different muzzle-target angles, firing distances, type of ammunition and weapon and barrel length. Based on a review of the literature and on the results of the experiments the authors could make the following statements of gunshot residues in angled contact and close contact gunshot: (1) gunshot residues on the target surface can be differentiated in a "inner" and "outer powder soot zone"; (2) the outer powder soot zone is much less visible than the inner powder soot zone and may lack on human skin; (3) with increasing muzzle target distance both inner and outer powder soot halo increase in size and decrease in density; (4) in angled shots the inner powder soot halo shows an eccentric, elliptic shape which points towards the muzzle, regardless of ammunition, calibre and barrel length; (5) the outer powder soot points away from the muzzle in angled contact and close contact shots.

Analysis of pulsed-neutron powder diffraction patterns of the icosahedral quasicrystals Pd3Siu and AlCuLiMg (three alloys) as twinned cubic crystals with large units.

PubMed Central

Pauling, L

1991-01-01

The low-Q peaks on three pulsed-neutron powder patterns (total, U differential, and Pd differential) of the icosahedral quasicrystal Pd3SiU have been indexed on the basis of an assumed cubic structure of the crystals that by icosahedral twinning form the quasicrystal. The primitive unit cube is found to have edge length 56.20 A and to contain approximately 12,100 atoms. Similar analyses of pulsed-neutron patterns of Al55Cu10Li35, Al55Cu10Li30Mg5, and Al510Cu125Li235Mg130 give values of the cube edge length 58.3, 58.5, and 58.4 A, respectively, with approximately 11,650 atoms in the unit cube. It is suggested that the unit contains eight complexes in the beta-W positions, plus some small interstitial groups of atoms, with each complex consisting of a centered icosahedron of 13 clusters, each of 116 atoms with the icosahedral structure found in the body-centered cubic crystal Mg32(Al,Zn)49. PMID:11607201

Analysis of pulsed-neutron powder diffraction patterns of the icosahedral quasicrystals Pd3Siu and AlCuLiMg (three alloys) as twinned cubic crystals with large units.

PubMed

Pauling, L

1991-08-01

The low-Q peaks on three pulsed-neutron powder patterns (total, U differential, and Pd differential) of the icosahedral quasicrystal Pd3SiU have been indexed on the basis of an assumed cubic structure of the crystals that by icosahedral twinning form the quasicrystal. The primitive unit cube is found to have edge length 56.20 A and to contain approximately 12,100 atoms. Similar analyses of pulsed-neutron patterns of Al55Cu10Li35, Al55Cu10Li30Mg5, and Al510Cu125Li235Mg130 give values of the cube edge length 58.3, 58.5, and 58.4 A, respectively, with approximately 11,650 atoms in the unit cube. It is suggested that the unit contains eight complexes in the beta-W positions, plus some small interstitial groups of atoms, with each complex consisting of a centered icosahedron of 13 clusters, each of 116 atoms with the icosahedral structure found in the body-centered cubic crystal Mg32(Al,Zn)49.

Synthesis of MSnO{sub 3} (M = Ba, Sr) nanoparticles by reverse micelle method and particle size distribution analysis by whole powder pattern modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, Jahangeer; Blakely, Colin K.; Bruno, Shaun R.

2012-09-15

Highlights: ► BaSnO{sub 3} and SrSnO{sub 3} nanoparticles synthesized using the reverse micelle method. ► Particle size and size distribution studied by whole powder pattern modeling. ► Nanoparticles are of optimal size for investigation in dye-sensitized solar cells. -- Abstract: Light-to-electricity conversion efficiency in dye-sensitized solar cells critically depends not only on the dye molecule, semiconducting material and redox shuttle selection but also on the particle size and particle size distribution of the semiconducting photoanode. In this study, nanocrystalline BaSnO{sub 3} and SrSnO{sub 3} particles have been synthesized using the microemulsion method. Particle size distribution was studied by whole powdermore » pattern modeling which confirmed narrow particle size distribution with an average size of 18.4 ± 8.3 nm for SrSnO{sub 3} and 15.8 ± 4.2 nm for BaSnO{sub 3}. These values are in close agreement with results of transmission electron microscopy. The prepared materials have optimal microstructure for successive investigation in dye-sensitized solar cells.« less

[The study of ultra-fine diamond powder used in magnetic head polishing slurry].

PubMed

Jin, Hong-Yun; Hou, Shu-En; Pan, Yong; Xiao, Hong-Yan

2008-05-01

In the present paper, atomic absorption spectrometry(AAS), inductively-coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and laser Raman spectroscopy (RM) were employed to study the commercial ultra-fine diamond powders prepared by the static pressure-catalyst method and used in magnetic head polishing slurry. The results of AAS and ICP-MS indicated that there were silicon oxide, Fe, Ni, Al and some other metal elements in the ultra-fine powders. XRD patterns showed the peaks of SiO2 at 2theta = 35.6 degrees, 39.4 degrees and 59.7 degrees and diamond sharp peaks in agreement with the results above. Diamond sharp peaks implied perfect crystal and high-hardness beneficial to high-efficiency in polishing. The broader Raman band of graphite at 1 592 cm(-1) observed by Raman analysis proved graphite existing in the diamond powders. In the TEM images, the size of ultra-fine powders was estimated between 0.1 and 0.5 microm distributed in a wide scope, however, sharp edges of the powder particles was useful to polish. The ultra-fine diamond powders have many advantages, for example, high-hardness, well abrasion performance, high-polishing efficiency and being useful in magnetic head polishing slurry. But, the impurities influence the polishing efficiency, shortening its service life and the wide distribution reduces the polishing precision. Consequently, before use the powders must be purified and classified. The purity demands is 99.9% and trace silicon oxide under 0.01% should be reached. The classification demands that the particle distribution should be in a narrower scope, with the mean size of 100 nm and the percentage of particles lager than 200 nm not over 2%.

Production of salbutamol sulfate for inhalation by high-gravity controlled antisolvent precipitation.

PubMed

Chiou, Herbert; Li, Li; Hu, Tingting; Chan, Hak-Kim; Chen, Jian-Feng; Yun, Jimmy

2007-02-22

The purpose of this study was to produce salbutamol sulfate (SS) as a model anti-asthmatic drug using high-gravity controlled precipitation (HGCP) through antisolvent crystallisation. An aqueous solution of SS was passed through a HGCP reactor with isopropanol as antisolvent to induce precipitation. Spray drying was employed to obtain dry powders. Scanning electron microscopy, X-ray powder diffraction (XRD), density measurement, thermal gravimetric analysis, and dynamic vapour sorption were carried out to characterise the powder physical properties. The aerosol performance of the powders was measured using an Aeroliser connected to a multiple stage liquid impinger operating at 60 L/min. The HGCP SS particles were elongated with 0.1 microm in width but varying length of several mum, which formed spherical agglomerates when spray dried. The particles showed the same XRD pattern and true density (1.3g/cm3) as the raw material, indicating that they belonged to the same crystalline form. However, the spray dried agglomerates had a much lower tapped density (0.1g/cm3) than the raw material (0.6g/cm3). Compared with the powder obtained by spray drying directly from an aqueous solution, the SS powders obtained from HGCP were much less hygroscopic (0.6% versus 10% water uptake at 90% RH). The in vitro aerosol performance showed a fine particle fraction FPFloaded and FPFemitted up to 54.5+/-4.9% and 71.3+/-10.0%, respectively. In conclusion, SS powder with suitable physical and aerosol properties can be obtained through antisolvent HGCP followed by spray drying.

Characterization of ball-milled carbon nanotube dispersed aluminum mixed powders

NASA Astrophysics Data System (ADS)

Maleque, M. A.; Abdullah, U.; Yaacob, I.; Ali, Y.

2016-04-01

Currently, carbon nanotube (CNT) is attracting much interest as fibrous materials for reinforcing aluminum matrix composites due to unique properties, such as high strength, elastic modulus, flexibility and high aspect ratios. However, the quality of the dispersion is the major concerning factor which determines the homogeneity of the enhanced mechanical and tribological properties of the composite. This work study and characterized carbon nanotube dispersion in ballmilled CNT-aluminum mixed powders with four different formulations such as 1, 1.5, 2 and 2.5 wt% CNT under high energy planetary ball milling operations. The ball milling was performed for two hours at constant milling speed of 250 rpm under controlled atmosphere. The characterization is performed using FESEM and EDX analyzer for mapping, elemental and line analysis. The experimental results showed homogeneous dispersion of CNTs in aluminum matrix. The composite mixture showed similar pattern from mapping, elemental and line analysis. Identification of only two peaks proved that controlled atmosphere during milling prevented the formation of inter metallic compounds such as aluminum carbide in the composite mixture. Therefore, this CNT-A1 composite powder mixture can be used for new nano-composite development without any agglomeration problem.

Macromolecular powder diffraction : structure solution via molecular.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Synthesis of samarium doped gadolinium oxide nanorods, its spectroscopic and physical properties

NASA Astrophysics Data System (ADS)

Boopathi, G.; Gokul Raj, S.; Ramesh Kumar, G.; Mohan, R.; Mohan, S.

2018-06-01

One-dimensional samarium doped gadolinium oxide [Sm:Gd2O3] nanorods have been synthesized successfully through co-precipitation technique in aqueous solution. The as-synthesized and calcined products were characterized by using powder X-ray diffraction pattern, Fourier transform Raman spectroscopy, thermogravimetric/differential thermal analysis, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-Visible spectrometry, photoluminescence spectrophotometer and X-ray photoelectron spectroscopy techniques. The obtained results are discussed in detailed manner.

Epoxy-resin patterns speed shell-molding of aluminum parts

NASA Technical Reports Server (NTRS)

1965-01-01

Half patterns cast from commercial epoxy resin containing aluminum powder are used for shell-molding of aluminum parts. The half patterns are cast in plastic molds of the original wooden pattern. Ten serviceable sand resin molds are made from each epoxy pattern.

Highly surface-roughened quasi-spherical silver powders in back electrode paste for silicon solar cells

NASA Astrophysics Data System (ADS)

Yin, Peng; Liu, Shouchao; Li, Qiuying; Chen, Xiaolei; Guo, Weihong; Wu, Chifei

2017-08-01

In our work, highly surface-roughened quasi-spherical silver powders with controllable size and superior dispersibility, which have narrow size distribution and relatively high tap density, were successfully prepared by reducing silver nitrate with ascorbic acid in aqueous solutions. Gum arabic (AG) was selected as dispersant to prevent the agglomeration of silver particles. Furthermore, the effects of preparation conditions on the characteristics of the powders were systematically investigated. By varying the concentration of the reactants, dosage of dispersant, the feeding modes, synthesis temperature and the pH value of the mixture solution of silver nitrate and AG, the resulted silver particles displayed controllable size, different morphologies and surface roughness. The spherical silver powder with mean particle size of 1.20 µm, tap density of 4.1 g cm-3 and specific area value of 0.46 m2 g-1 was prepared by adjusting preparation conditions. The AG absorbed on the surface preventing the silver particles from diffusion and aggregation was proved by the ultraviolet spectra. Observations of SEM images showed that the as-prepared silver powders were relatively monodisperse silver spheres with highly roughened surface and the particle size was controllable from 1 µm to 5 µm, specific surface area value from approximately 0.2 m2 g-1 to 0.8 m2 g-1. X-ray diffraction (XRD) patterns, energy dispersive spectroscopy (EDS), x-ray photoelectron spectra (XPS) and thermal gravity analysis (TGA) demonstrated high crystallinity and purity of the obtained silver powders.

X-Ray Diffraction for In-Situ Mineralogical Analysis of Planetesimals.

NASA Astrophysics Data System (ADS)

Sarrazin, P.; Blake, D. F.; Dera, P.; Downs, R. T.; Taylor, J.

2017-12-01

X-ray diffraction (XRD) is a general purpose technique for definitive, quantitative mineralogical analysis. When combined with XRF data for sample chemistry, XRD analyses yield as complete a characterization as is possible by any spacecraft-capable techniques. The MSL CheMin instrument, the first XRD instrument flown in space, has been used to establish the quantitative mineralogy of the Mars global soil, to discover the first habitable environment on another planet, and to provide the first in-situ evidence of silicic volcanism on Mars. CheMin is now used to characterize the depositional and diagenetic environments associated with the mudstone sediments of lower strata of Mt. Sharp. Conventional powder XRD requires samples comprised of small grains presented in random orientations. In CheMin, sample cells are vibrated to cause loose powder to flow within the cell, driven by granular convection, which relaxes the requirement for fine grained samples. Nevertheless, CheMin still requires mechanisms to collect, crush, sieve and deliver samples before analysis. XTRA (Extraterrestrial Regolith Analyzer) is an evolution of CheMin intended to analyze fines in as-delivered surface regolith, without sample preparation. Fine-grained regolith coats the surfaces of most airless bodies in the solar system, and because this fraction is typically comminuted from the rocky regolith, it can often be used as a proxy for the surface as a whole. HXRD (Hybrid-XRD) is concept under development to analyze rocks or soils without sample preparation. Like in CheMin, the diffracted signal is collected with direct illumination CCD's. If the material is sufficiently fine-grained, a powder XRD pattern of the characteristic X-ray tube emission is obtained, similar to CheMin or XTRA. With coarse grained crystals, the white bremsstrahlung radiation of the tube is diffracted into Laue patterns. Unlike typical Laue applications, HXRD uses the CCD's capability to distinguish energy and analyze the "colors" of each Laue spot, which enable phase identification. The concept was demonstrated with prototypes and dedicated crystallographic software was developed for identification the minerals responsible for the Laue patterns. High TRL subsystems are under development for future deployment opportunities of these new XRD instruments.

Effect of amino acid dopants on the spectral, optical, mechanical and thermal properties of potassium acid phthalate crystals for possible optoelectronic and frequency doubling applications

NASA Astrophysics Data System (ADS)

Prakash, J. Thomas Joseph; Gnanaraj, J. Martin Sam; Dhavud, S. Shek; Ekadevasena, S.

2015-09-01

Undoped and amino acid (L-Arginine and L-Valine) doped KAP crystals were grown by slow evaporation solution growth technique. The changes in the structural, spectral, optical, mechanical and thermal properties were observed. The sharp prominent peaks in the indexed powder XRD pattern confirms the crystalline nature of the sample. Optical studies reveal that the crystal is transparent in the entire visible light region. Thermal stability was checked by TG/DTA analysis. The mechanical stability was evaluated from Vicker's microhardness test. The SHG efficiency for the title materials was tested with different particle sizes by the Kurtz and Perry powder method, which established the existence of phase matching.

Homogeneity of ball milled ceramic powders: Effect of jar shape and milling conditions.

PubMed

Broseghini, M; D'Incau, M; Gelisio, L; Pugno, N M; Scardi, P

2017-02-01

This paper contains data and supporting information of and complementary to the research article entitled " Effect of jar shape on high-energy planetary ball milling efficiency: simulations and experiments " (Broseghini et al.,) [1]. Calcium fluoride (CaF 2 ) was ground using two jars of different shape (cylindrical and half-moon) installed on a planetary ball-mill, exploring different operating conditions (jar-to-plate angular velocity ratio and milling time). Scanning Electron Microscopy (SEM) images and X-Ray Powder Diffraction data (XRPD) were collected to assess the effect of milling conditions on the end-product crystallite size. Due to the inhomogeneity of the end product, the Whole Powder Pattern Model (WPPM, (Scardi, 2008) [2]) analysis of XRPD data required the hypothesis of a bimodal distribution of sizes - respectively ground (fine fraction) and less-to-not ground (coarse fraction) - confirmed by SEM images and suggested by the previous literature (Abdellatief et al., 2013) [3,4]. Predominance of fine fraction clearly indicates optimal milling conditions.

High-resolution inelastic neutron scattering and neutron powder diffraction study of the adsorption of dihydrogen by the Cu(II) metal-organic framework material HKUST-1

NASA Astrophysics Data System (ADS)

Callear, Samantha K.; Ramirez-Cuesta, Anibal J.; David, William I. F.; Millange, Franck; Walton, Richard I.

2013-12-01

We present new high-resolution inelastic neutron scattering (INS) spectra (measured using the TOSCA and MARI instruments at ISIS) and powder neutron diffraction data (measured on the diffractometer WISH at ISIS) from the interaction of the prototypical metal-organic framework HKUST-1 with various dosages of dihydrogen gas. The INS spectra show direct evidence for the sequential occupation of various distinct sites for dihydrogen in the metal-organic framework, whose population is adjusted during increasing loading of the guest. The superior resolution of TOSCA reveals subtle features in the spectra, not previously reported, including evidence for split signals, while complementary spectra recorded on MARI present full information in energy and momentum transfer. The analysis of the powder neutron patterns using the Rietveld method shows a consistent picture, allowing the crystallographic indenisation of binding sites for dihydrogen, thus building a comprehensive picture of the interaction of the guest with the nanoporous host.

Upconversion luminescence of Er3+/Yb3+ doped Sr5(PO4)3OH phosphor powders

NASA Astrophysics Data System (ADS)

Mokoena, P. P.; Swart, H. C.; Ntwaeaborwa, O. M.

2018-04-01

Sr5(PO4)3OH co-doped with Er3+and Yb3+ powder phosphors were synthesized by urea combustion method. The crystal structure was analyzed using X-ray diffraction (XRD). Particle morphology was analyzed using a Jeol JSM 7800F thermal field emission scanning electron microscope (FE-SEM) and the chemical composition analysis was carried out using an Oxford Instruments AzTEC energy dispersive spectrometer (EDS) attached to the FE-SEM. Upconversion emission was measured by using a FLS980 Spectrometer equipped with a 980 nm NIR laser as the excitation source, and a photomultiplier (PMT) detector. The XRD data of the Sr5(PO4)3OH powder exhibited characteristic diffraction patterns of the hexagonal structure referenced in the standard JCPDS card number 00-033-1348. The sharp peaks revealed the formation of crystalline Sr5(PO4)3OH. The powders were made up of hexagonal nanospheres. The enhanced red emission due to the 4F9/2 → 4I15/2 transitions of Er3+ was observed and was attributed to up conversion (UC) energy transfer from Yb3+. The upconversion energy transfer mechanism from Yb3+ to Er3+ is discussed.

The Survey of Cronobacter spp. (formerly Enterbacter sakazakii) in Infant and Follow-up Powdered Formula in China in 2012.

PubMed

Pei, Xiao Yan; Yan, Lin; Zhu, Jiang Hui; Li, Ning; Guo, Yun Chang; Fu, Ping; Jia, Hua Yun; Zhang, Xiu Li; Yang, Xiao Rong; Yang, Da Jin

2016-02-01

To determine Cronobacter spp. contamination in infant and follow-up powdered formula in China. All of 2282 samples were collected from the retail markets in China from January 2012 to December 2012, and analyzed for Cronobacter spp. by the Chinese National Food Safety Standard. Characterization of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE) with XbaI and SpeI restriction enzymes. Cronobacter spp. strains were isolated from 25 samples, and the positive rates in infant powdered formulas and follow-up powdered formulas were 0.90% (10/1011) and 1.18% (15/1271), respectively. Analysis of variable data regarding different purchasing store formats, seasonality, and production locations as well as comparison of infant versus follow-up formulas did not reveal statistically significant factors. During the sampling period, one of six surveillance zones did exhibit a statistically significant trend towards higher positive rate. PFGE characterization of Cronobacter spp. to elucidate genetic diversity revealed only three pairs of Cronobacter spp. out of 25 having the same PFGE patterns. The current investigation indicated a lower positive rate of Cronobacter spp. in the powdered formula in China. This evidence suggested contamination originating from multiple different sources during the manufacturing process. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Monoclinic β-Li2TiO3 nanocrystalline particles employing novel urea assisted solid state route: Synthesis, characterization and sintering behavior

NASA Astrophysics Data System (ADS)

Tripathi, Biranchi M.; Mohanty, Trupti; Prakash, Deep; Tyagi, A. K.; Sinha, P. K.

2017-07-01

Pure phase monoclinic nano-crystalline Li2TiO3 powder was synthesized by a novel urea assisted solid state synthesis method using readily available and economical precursors. A single phase and well crystalline Li2TiO3 powder has been obtained at slightly lower temperature (600-700 °C) and shorter duration (2 h) as compared to the conventional solid state method. The proposed method has significant advantages in comparison to other viable methods mainly in terms of phase purity, powder properties and sinterability. Analysis of chemical composition using inductively coupled plasma atomic emission spectroscopy (ICP-AES) shows no loss of lithium from Li2TiO3 in the proposed method. The emergence of monoclinic Li2TiO3 phase was confirmed by X-ray diffraction (XRD) pattern of as-synthesized powder. The crystallite size of Li2TiO3 powder was calculated to be in the range of 15-80 nm, which varied as a function of urea composition and temperature. The morphology of as-prepared Li2TiO3 powders was examined by scanning electron microscope (SEM). The effect of urea composition on phase and morphology was investigated so as to delineate the role of urea. Upon sintering at < 1000 °C temperature, the Li2TiO3 powder compact attained about 98% of the theoretical density with fine grained (grain size: 2-3 μm) microstructure. It indicates excellent sinter-ability of Li2TiO3 powder synthesized by the proposed method. The fine grained structure is desirable for better tritium breeding performance of Li2TiO3. Electrochemical impedance spectroscopy at variable temperature showed good electrical properties of Li2TiO3. The proposed method is simple, anticipated to be cost effective and convenient to realise for large scale production of phase pure nanocrystalline and having significantly enhanced sinter-ability Li2TiO3 powder.

Effect of device design on the aerosolization of a carrier-based dry powder inhaler--a case study on Aerolizer(®) Foradile (®).

PubMed

Zhou, Qi Tony; Tong, Zhenbo; Tang, Patricia; Citterio, Mauro; Yang, Runyu; Chan, Hak-Kim

2013-04-01

The objective of this study is to investigate the effect of device design of the Aerolizer(®) on the aerosolization of a carrier-based dry powder inhaler formulation (Foradile(®)). The Aerolizer was modified by reducing the air inlet size and mouthpiece length to 1/3 of the original dimensions, or by increasing the grid voidage. Aerosolization of the powder formulation was assessed on a multi-stage liquid impinger at air flow rates of 30, 60, and 100 L/min. Coupled CFD-DEM simulations were performed to investigate the air flow pattern and particle impaction. There was no significant difference in the aerosolization behavior between the original and 1/3 mouthpiece length devices. Significant increases in FPF total and FPF emitted were demonstrated when the inlet size was reduced, and the results were explained by the increases in air velocity and turbulence from the CFD analysis. No significant differences were shown in FPF total and FPF emitted when the grid voidage was increased, but more drugs were found to deposit in induction port and to a lesser extent, the mouthpiece. This was supported by the CFD-DEM analysis which showed the particle-device collisions mainly occurred in the inhaler chamber, and the cross-grid design increased the particle-device collisions on both mouthpiece and induction port. The air inlet size and grid structure of the Aerolizer(®) were found to impact significantly on the aerosolization of the carrier-based powder.

Experimental studies on a novel roll-to-roll powder hot embossing for large-area fabrication of micropyramid arrays on polymers

NASA Astrophysics Data System (ADS)

Yi, Peiyun; Deng, Yujun; Shu, Yunyi; Peng, Linfa

2018-08-01

Roll-to-roll (R2R) hot embossing is regarded as a cost-effective replication technology to fabricate microstructures on polymer films. However, the characteristics of continuous and fast forming for the R2R hot embossing process limits material flow during the filling stage and results in significant springback during the demolding stage. To resolve this issue, this study proposed a novel R2R powder hot embossing process, which combines the merits of the continuous fabrication of R2R hot embossing and near-net-shape forming of powder sintering and also decreases the whole cycle of the fabrication from films to microstructures. First, the relation between the molten layer thickness and processing parameters was discussed and an analytical model was established to predict the feed of the polymeric powder during R2R powder hot embossing. Then, with the use of a micro-pyramid array mold, the impact of the process parameters including mold temperature, feeding speed and applied force on the geometrical dimension of the patterned microstructures was discussed. Last, based on the response surface analysis, a process window, in terms of the mold temperature of 132 °C –145 °C, feeding speed of 0.1–1.4 m min‑1 and applied force of 15–50 kgf was determined for the continuous fabrication of completely-filled micropyramid arrays with the R2R powder hot embossing process. This research demonstrated the feasibility and superiority of the proposed R2R powder hot embossing process in continuously fabricating micropatterned structures on polymeric films.

Growth, crystalline perfection, spectral, thermal and theoretical studies on imidazolium L-tartrate crystals.

PubMed

Meena, K; Muthu, K; Meenatchi, V; Rajasekar, M; Bhagavannarayana, G; Meenakshisundaram, S P

2014-04-24

Transparent optical quality single crystals of imidazolium L-tartrate (IMLT) were grown by conventional slow evaporation solution growth technique. Crystal structure of the as-grown IMLT was determined by single crystal X-ray diffraction analysis. Thermal analysis reveals the purity of the crystal and the sample is stable up to the melting point. Good transmittance in the visible region is observed and the band gap energy is estimated using diffuse reflectance data by the application of Kubelka-Munk algorithm. The powder X-ray diffraction study reveals the crystallinity of the as-grown crystal and it is compared with that of the experimental one. An additional peak in high resolution X-ray diffraction (HRXRD) indicates the presence of an internal structural low angle boundary. Second harmonic generation (SHG) activity of IMLT is significant as estimated by Kurtz and Perry powder technique. HOMO-LUMO energies and first-order molecular hyperpolarizability of IMLT have been evaluated using density functional theory (DFT) employing B3LYP functional and 6-31G(d,p) basis set. The optimized geometry closely resembles the ORTEP. The vibrational patterns present in the molecule are confirmed by FT-IR coinciding with theoretical patterns. Copyright © 2014 Elsevier B.V. All rights reserved.

The inconsistency in adsorption properties and powder XRD data of MOF-5 is rationalized by framework interpenetration and the presence of organic and inorganic species in the nanocavities.

PubMed

Hafizovic, Jasmina; Bjørgen, Morten; Olsbye, Unni; Dietzel, Pascal D C; Bordiga, Silvia; Prestipino, Carmelo; Lamberti, Carlo; Lillerud, Karl Petter

2007-03-28

MOF-5 is the archetype metal-organic framework and has been subjected to numerous studies the past few years. The focal point of this report is the pitfalls related to the MOF-5 phase identification based on powder XRD data. A broad set of conditions and procedures have been reported for MOF-5 synthesis. These variations have led to materials with substantially different adsorption properties (specific surface areas in the range 700 to 3400 m(2)/g). The relatively low weight loss observed for some as synthesized samples upon solvent removal is also indicative of a low pore volume. Regrettably, these materials have all been described as MOF-5 without any further comments. Furthermore, the reported powder XRD patterns hint at structural differences: The variations in surface area are accompanied by peak splitting phenomena and rather pronounced changes in the relative peak intensities in the powder XRD patterns. In this work, we use single-crystal XRD to investigate structural differences between low and high surface area MOF-5. The low surface area MOF-5 sample had two different classes of crystals. For the dominant phase, Zn(OH)2 species partly occupied the cavities. The presence of Zn species makes the hosting cavity and possibly also adjacent cavities inaccessible and thus efficiently reduces the pore volume of the material. Furthermore, the minor phase consisted of doubly interpenetrated MOF-5 networks, which lowers the adsorption capacity. The presence of Zn species and lattice interpenetration changes the symmetry from cubic to trigonal and explains the peak splitting observed in the powder XRD patterns. Pore-filling effects from the Zn species (and partly the solvent molecules) are also responsible for the pronounced variations in powder XRD peak intensities. This latter conclusion is particularly useful for predicting the adsorption properties of a MOF-5-type material from powder XRD.

Design, characterization, and aerosol dispersion performance modeling of advanced spray-dried microparticulate/nanoparticulate mannitol powders for targeted pulmonary delivery as dry powder inhalers.

PubMed

Li, Xiaojian; Vogt, Frederick G; Hayes, Don; Mansour, Heidi M

2014-04-01

The purpose was to design and characterize inhalable microparticulate/nanoparticulate dry powders of mannitol with essential particle properties for targeted dry powder delivery for cystic fibrosis mucolytic treatment by dilute organic solution spray drying, and, in addition, to tailor and correlate aerosol dispersion performance delivered as dry powder inhalers based on spray-drying conditions and solid-state physicochemical properties. Organic solution advanced spray drying from dilute solution followed by comprehensive solid-state physicochemical characterization and in vitro dry powder aerosolization were used. The particle size distribution of the spray-dried (SD) powders was narrow, unimodal, and in the range of ∼500 nm to 2.0 μm. The particles possessed spherical particle morphology, relatively smooth surface morphology, low water content and vapor sorption (crystallization occurred at exposure above 65% relative humidity), and retention of crystallinity by polymorphic interconversion. The emitted dose, fine particle fraction (FPF), and respirable fraction (RF) were all relatively high. The mass median aerodynamic diameters were below 4 μm for all SD mannitol aerosols. The in vitro aerosol deposition stage patterns could be tailored based on spray-drying pump rate. Positive linear correlation was observed between both FPF and RF values with spray-drying pump rates. The interplay between various spray-drying conditions, particle physicochemical properties, and aerosol dispersion performance was observed and examined, which enabled tailoring and modeling of high aerosol deposition patterns.

Design, Characterization, and Aerosol Dispersion Performance Modeling of Advanced Spray-Dried Microparticulate/Nanoparticulate Mannitol Powders for Targeted Pulmonary Delivery as Dry Powder Inhalers

PubMed Central

Li, Xiaojian; Vogt, Frederick G.; Hayes, Don

2014-01-01

Abstract Background: The purpose was to design and characterize inhalable microparticulate/nanoparticulate dry powders of mannitol with essential particle properties for targeted dry powder delivery for cystic fibrosis mucolytic treatment by dilute organic solution spray drying, and, in addition, to tailor and correlate aerosol dispersion performance delivered as dry powder inhalers based on spray-drying conditions and solid-state physicochemical properties. Methods: Organic solution advanced spray drying from dilute solution followed by comprehensive solid-state physicochemical characterization and in vitro dry powder aerosolization were used. Results: The particle size distribution of the spray-dried (SD) powders was narrow, unimodal, and in the range of ∼500 nm to 2.0 μm. The particles possessed spherical particle morphology, relatively smooth surface morphology, low water content and vapor sorption (crystallization occurred at exposure above 65% relative humidity), and retention of crystallinity by polymorphic interconversion. The emitted dose, fine particle fraction (FPF), and respirable fraction (RF) were all relatively high. The mass median aerodynamic diameters were below 4 μm for all SD mannitol aerosols. Conclusion: The in vitro aerosol deposition stage patterns could be tailored based on spray-drying pump rate. Positive linear correlation was observed between both FPF and RF values with spray-drying pump rates. The interplay between various spray-drying conditions, particle physicochemical properties, and aerosol dispersion performance was observed and examined, which enabled tailoring and modeling of high aerosol deposition patterns. PMID:24502451

Behavioral and catastrophic drift of invertebrates in two streams in northeastern Wyoming

USGS Publications Warehouse

Wangsness, David J.; Peterson, David A.

1980-01-01

Invertebrate drift samples were collected in August 1977 from two streams in the Powder River structural basin in northeastern Wyoming. The streams are Clear Creek, a mountain stream, and the Little Powder River, a plains stream. Two major patterns of drift were recognized. Clear Creek was sampled during a period of normal seasonal conditions. High drift rates occurred during the night indicating a behavioral drift pattern that is related to the benthic invertebrate density and carrying capacity of the stream substrates. The mayfly genes Baetis, a common drift organism, dominated the peak periods of drift in Clear Creek. The Little Powder River has a high discharge during the study period. Midge larvae of the families Chironomidae and Ceratopogonidae, ususally not common in drift, dominated the drift community. The dominance of midge larvae, the presence of several other organisms not common in drift, and the high discharge during the study period caused a catastrophic drift pattern. (USGS)

First-principles prediction of low-energy structures for AlH3

NASA Astrophysics Data System (ADS)

Sun, Shoutian; Ke, Xuezhi; Chen, Changfeng; Tanaka, Isao

2009-01-01

We report density-functional calculations that predict ten different low-energy structures for aluminum hydride AlH3 with space groups Pnma , P6/mmm , I4/mcm , P4/mbm , P4/nmm , Pm3¯m , P21/m , P21/c , Pbcm , and P4/n . Phonon calculations within harmonic approximation reveal unstable modes in the P6/mmm , I4/mcm , P4/mbm , P4/nmm , Pm3¯m , P21/m , and P21/c structures, indicating that they are unstable at low temperatures. The calculations show that the thermodynamic stabilities for AlH3 with space groups Pnma , Pbcm , and P4/n are overall close to the existing α - and γ-AlH3 . From x-ray powder-diffraction patterns, the simulated main-peak positions for AlH3 (P4/n) are in good agreement with experimental δ-AlH3 . A full Rietveld analysis reveals that the fitting space groups R3¯c , Pbcm , and Pnma to the experimental x-ray powder-diffraction pattern of α-AlH3 gives almost the same satisfactory result.

Experimental model of developing and analysis of lip prints in atypical surface: A metallic straw (bombilla)

PubMed Central

Fonseca, Gabriel M.; Bonfigli, Esteban; Cantín, Mario

2014-01-01

Background: The interaction between the offender and the victim produces visible or latent prints on objects and utensils. The study of lip prints has reportedly stayed away from the basic cinematic concept of the lip-to-surface relationship. Materials and Methods: Three regular powders were used to reveal the latent lip prints on a typical metallic straw called bombilla, and the revealed prints were photographed, preserved, and analyzed. Results: Better definition was observed in the lower lip print, and nine anatomical patterns were identified, but a higher definition of wrinkles was observed with indestructible white powder. Conclusion: Knowledge of labial dynamics, the real value of the processed surfaces, and the need for testing in field conditions are discussed. PMID:25125921

Quantitative analysis of crystalline pharmaceuticals in tablets by pattern-fitting procedure using X-ray diffraction pattern.

PubMed

Takehira, Rieko; Momose, Yasunori; Yamamura, Shigeo

2010-10-15

A pattern-fitting procedure using an X-ray diffraction pattern was applied to the quantitative analysis of binary system of crystalline pharmaceuticals in tablets. Orthorhombic crystals of isoniazid (INH) and mannitol (MAN) were used for the analysis. Tablets were prepared under various compression pressures using a direct compression method with various compositions of INH and MAN. Assuming that X-ray diffraction pattern of INH-MAN system consists of diffraction intensities from respective crystals, observed diffraction intensities were fitted to analytic expression based on X-ray diffraction theory and separated into two intensities from INH and MAN crystals by a nonlinear least-squares procedure. After separation, the contents of INH were determined by using the optimized normalization constants for INH and MAN. The correction parameter including all the factors that are beyond experimental control was required for quantitative analysis without calibration curve. The pattern-fitting procedure made it possible to determine crystalline phases in the range of 10-90% (w/w) of the INH contents. Further, certain characteristics of the crystals in the tablets, such as the preferred orientation, size of crystallite, and lattice disorder were determined simultaneously. This method can be adopted to analyze compounds whose crystal structures are known. It is a potentially powerful tool for the quantitative phase analysis and characterization of crystals in tablets and powders using X-ray diffraction patterns. Copyright 2010 Elsevier B.V. All rights reserved.

High Pressure X-Ray Diffraction Studies of Nanocrystalline Materials

NASA Technical Reports Server (NTRS)

Palosz, B.; Stel'makh, S.; Grzanka, E.; Gierlotka, S.; Palosz, W.

2004-01-01

Experimental evidence obtained for a variety of nanocrystalline materials suggest that the crystallographic structure of a very small size particle deviates from that in the bulk crystals. In this paper we show the effect of the surface of nanocrystals on their structure by the analysis of generation and distribution of macro- and micro-strains at high pressures and their dependence on the grain size in nanocrystalline powders of Sic. We studied the structure of Sic nanocrystals by in-situ high-pressure powder diffraction technique using synchrotron and neutron sources and hydrostatic or isostatic pressure conditions. The diffraction measurements were done in HASYLAB at DESY using a Diamond Anvil Cell (DAC) in the energy dispersive geometry in the diffraction vector range up to 3.5 - 4/A and under pressures up to 50 GPa at room temperature. In-situ high pressure neutron diffraction measurements were done at LANSCE in Los Alamos National Laboratory using the HIPD and HIPPO diffractometers with the Paris-Edinburgh and TAP-98 cells, respectively, in the diffraction vector range up to 26 Examination of the response of the material to external stresses requires nonstandard methodology of the materials characterization and description. Although every diffraction pattern contains a complete information on macro- and micro-strains, a high pressure experiment can reveal only those factors which contribute to the characteristic diffraction patterns of the crystalline phases present in the sample. The elastic properties of powders with the grain size from several nm to micrometers were examined using three methodologies: (l), the analysis of positions and widths of individual Bragg reflections (used for calculating macro- and micro-strains generated during densification) [I], (2). the analysis of the dependence of the experimental apparent lattice parameter, alp, on the diffraction vector Q [2], and (3), the atomic Pair Distribution Function (PDF) technique [3]. The results of our studies show, that Sic nanocrystals have the features of two phases, each with its distinct elastic properties. and under pressures up to 8 GPa.

Fluorescence Analysis on the Roots of Rauvolfia Serpentina (L.) Benth. Ex Kurz Under UV Radiation

PubMed Central

Selvam, A.B.D; Bandyopadhyay, S.

2005-01-01

The present study deals with an analysis of the roots of Rauvolfia serpentine (L) Benth. Ex Kurz under ultraviolet radiation and also under daylight. The coarsely powdered roots were treated with various chemical reagents and the characteristic fluorescence patterns emitted were recorded and are reported in this paper. This study was undertaken as a pharmacognostic standardization to ascertain the authenticity of the roots of this plant in its crude form and also to check any adulteration that may be used in trade. PMID:22557172

Fatigue of LiNi0.8Co0.15Al0.05O2 in commercial Li ion batteries

NASA Astrophysics Data System (ADS)

Kleiner, Karin; Dixon, Ditty; Jakes, Peter; Melke, Julia; Yavuz, Murat; Roth, Christina; Nikolowski, Kristian; Liebau, Verena; Ehrenberg, Helmut

2015-01-01

The degradation of LiNi0.8Co0.15Al0.05O2 (LNCAO), a cathode material in lithium-ion-batteries, was studied using in situ powder diffraction and in situ Ni K edge X-ray absorption spectroscopy (XAS). The fatigued material was taken from a 7 Ah battery which was cycled for 34 weeks under defined durability conditions. Meanwhile, a cell was stored, as reference, under controlled conditions without electrochemical treatment. The fatigued LNCAO used in this study showed a capacity loss of 26% ± 9% compared to the non-cycled material. During charge and discharge the local and the overall structure of LNCAO was investigated by X-ray near edge structure (XANES) analysis, the extended X-ray absorption fine structure (EXAFS) analysis and by using Rietveld refinement of in situ powder diffraction patterns. Both powder diffraction and XAS revealed additional, rhombohedral phases which do not change with electrochemical cycling. Moreover, a phase with the lattice parameters of fully lithiated LNCAO was still present in the fatigued material at high potentials, while it was absent in the non-fatigued reference material. The coexistence of these phases is described by domains within the LNCAO particles, in correlation with the observed fatigue.

Effect of aging temperature on formation of sol-gel derived fluor-hydroxyapatite nanoparticles.

PubMed

Joughehdoust, S; Behnamghader, A; Jahandideh, R; Manafi, S

2010-04-01

Synthetic hydroxyapatite (HA) has been recognized as one of the most important bone substitute materials in orthopaedics and dentistry over past few decades because of its chemical and biological similarity to the mineral phase of human bone. One solution for reduction the solubility of HA in biological environments is replacing F- by OH in HA structure and forming fluor-hydroxyapatite (FHA) solid solution. In this paper, FHA nanoparticles were successfully synthesized by a sol-gel method. Also, the influence of aging temperature on formation of FHA powder was studied. Equimolar solutions of calcium nitrate tetrahydrate, triethyl phosphite and ammonium fluoride in ethanol were used as Ca, P and F precursors. After aging at different temperatures, the synthesized powders were heat treated at 550 degrees C. The powders were investigated with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), selected area electron diffraction pattern (SAED), energy dispersive analysis of X-ray (EDAX) and zetasizer measurement. The results of XRD proved the presence of fluorapatite (FA) and HA in all samples. In addition, the formation of FHA was confirmed by FT-IR results. XRD studies also showed that the crystallites were in nanometric scale. At the same time, this result was in good agreement with the result of zetasizer analysis.

Nanograin Ceramic Optical Composite Window

DTIC Science & Technology

2005-07-15

parts are sintered in air at 1100 C̊. Table 1: Carbon content of the calcined Alumina- Zirconia powders analyzed by LECO Calcination Temperature Carbon...estimated particle size of the Alumina and Zirconia powders Material name Surface area (m2/g) Estimated particle size (nm) Alumina 315.7 4.7 Zirconia...200 300 400 500 600 700 800 900 1000 2-Theta - Scale 20 30 40 50 60 70 80 Figure 3: XRD patterns of zirconia powder prepared by sonochemical method

The use of Electronic Speckle Pattern Interferometry (ESPI) in the crack propagation analysis of epoxy resins

NASA Astrophysics Data System (ADS)

Herbert, D. P.; Al-Hassani, A. H. M.; Richardson, M. O. W.

The ESPI (electronic speckle pattern interferometry) technique at high magnification levels is demonstrated to be of considerable value in interpreting the fracture behaviour of epoxy resins. The fracture toughness of powder coating system at different thicknesses has been measured using a TDCB (tapered double cantilever beam) technique and the deformation zone at the tip of the moving crack monitored. Initial indications are that a mechanistic changeover occurs at a critical bond (coating) thickness and that this is synonymous with the occurence of a fracture toughness maximum, which in turn is associated with a deformation zone of specific diameter.

Mechanical behaviour of pressed and sintered titanium alloys obtained from master alloy addition powders.

PubMed

Bolzoni, L; Esteban, P G; Ruiz-Navas, E M; Gordo, E

2012-11-01

The fabrication of the workhorse Ti-6Al-4V alloy and of the Ti-3Al-2.5V alloy was studied considering the master alloy addition variant of the blending elemental approach conventionally used for titanium powder metallurgy. The powders were characterised by means thermal analysis and X-ray diffraction and shaped by means of uniaxial pressing. The microstructural evolution with the sintering temperature (900-1400 °C) was evaluated by SEM and EDS was used to study the composition. XRD patterns as well as the density by Archimedes method were also obtained. The results indicate that master alloy addition is a suitable way to fabricate well developed titanium alloy but also to produce alloy with the desired composition, not available commercially. Density of 4.3 g/cm³ can be obtained where a temperature higher than 1200 °C is needed for the complete diffusion of the alloying elements. Flexural properties comparable to those specified for wrought Ti-6Al-4V medical devices are, generally, obtained. Copyright © 2012 Elsevier Ltd. All rights reserved.

Investigation of phase evolution of CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) by in situ synchrotron high-temperature powder diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouyang, Xin; Huang, Saifang; School of Materials Science and Technology, China University of Geosciences

2014-03-15

In situ synchrotron X-ray powder diffraction was used to study the high-temperature phase evolution of CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) precursors prepared via solid-state and sol–gel methods. After the precursors are heated to 1225 °C, the CCTO phase is the main phase observed in the calcined powder, with the presence of some minor impurities. Comparing the two precursors, we found that the onset temperature for the CCTO phase formation is 800 °C in the sol–gel precursor, lower than that in the solid-state precursor (875 °C). Intermediate phases were only observed in the sol–gel precursor. Both precursors are able to bemore » calcined to sub-micrometric sized powders. Based on the synchrotron data along with differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), the phase formation sequence and mechanism during calcination are proposed in this study. -- Graphical abstract: The in situ synchrotron HT-XRD patterns of CCTO sol–gel and solid-state precursor. Highlights: • Phase formation sequence/mechanism in two CCTO precursors has been established. • Formation temperature of CCTO via sol–gel method is lower than solid-state method. • Intermediate phases are only observed in the sol–gel precursor. • Both precursors are able to be calcined into sub-micrometric sized powders.« less

Effects of red pepper powder on microbial communities and metabolites during kimchi fermentation.

PubMed

Jeong, Sang Hyeon; Lee, Hyo Jung; Jung, Ji Young; Lee, Se Hee; Seo, Hye-Young; Park, Wan-Soo; Jeon, Che Ok

2013-01-01

To investigate the effects of red pepper powder on kimchi fermentation, Baechu (Chinese cabbage) and Mu (radish) kimchi, with and without red pepper powder, were prepared and their characteristics, including pH, colony-forming units (CFU), microbial communities, and metabolites, were periodically monitored for 40days. Measurements of pH and CFU showed that the lag phases of kimchi fermentation were clearly extended by the addition of red pepper powder. Microbial community analysis using a barcoded pyrosequencing analysis showed that the bacterial diversities in kimchi with red pepper powder decreased more slowly than kimchi without red pepper powder as kimchi fermentation progressed. The kimchi microbial communities were represented mainly by the genera Leuconostoc and Lactobacillus in all kimchi, and the abundance of Weissella was negligible in kimchi without red pepper powder. However, interestingly, kimchi with red pepper powder contained much higher proportions of Weissella than kimchi without red pepper powder, while the proportions of Leuconostoc and Lactobacillus were evidently lower in kimchi with red pepper powder compared to kimchi without red pepper powder. Metabolite analysis using a (1)H NMR technique also showed that the fermentation of kimchi with red pepper powder progressed a little more slowly than that of kimchi without red pepper powder. Principle component analysis using microbial communities and metabolites supported the finding that the addition of red pepper powder into kimchi resulted in the slowing of the kimchi fermentation process, especially during the early fermentation period and influenced the microbial succession and metabolite production during the kimchi fermentation processes. Copyright © 2012 Elsevier B.V. All rights reserved.

Floating matrix tablets based on low density foam powder: effects of formulation and processing parameters on drug release.

PubMed

Streubel, A; Siepmann, J; Bodmeier, R

2003-01-01

The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i). polypropylene foam powder, (ii). matrix-forming polymer(s), (iii). drug, and (iv). filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 degrees C. Different types of matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of matrix former. The release rate could effectively be modified by varying the "matrix-forming polymer/foam powder" ratio, the initial drug loading, the tablet geometry (radius and height), the type of matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.

Determination of nuclear quadrupolar parameters using singularities in field-swept NMR patterns.

PubMed

Ichijo, Naoki; Takeda, Kazuyuki; Yamada, Kazuhiko; Takegoshi, K

2016-10-07

We propose a simple data-analysis scheme to determine the coupling constant and the asymmetry parameter of nuclear quadrupolar interactions in field-swept nuclear magnetic resonance (NMR) for static powder samples. This approach correlates the quadrupolar parameters to the positions of the singularities, which can readily be found out as sharp peaks in the field-swept pattern. Moreover, the parameters can be determined without quantitative acquisition and elaborate calculation of the overall profile of the pattern. Since both experimental and computational efforts are significantly reduced, the approach presented in this work will enhance the power of the field-swept NMR for yet unexplored quadrupolar nuclei. We demonstrate this approach in 33 S in α-S 8 and 35 Cl in chloranil. The accuracy of the obtained quadrupolar parameters is also discussed.

The Use and the Prescription Pattern of Traditional Chinese Medicine Among Urolithiasis Patients in Taiwan: A Population-Based Study.

PubMed

Lin, Po-Hung; Lin, Shun-Ku; Hsu, Ren-Jun; Cheng, Kuan-Chen; Liu, Jui-Ming

2016-01-01

To investigate the pattern of Traditional Chinese Medicine (TCM) usage for urolithiasis patients in Taiwan and to determine the most common Chinese herbal products used for urolithiasis. Retrospective review of urolithiasis patients treated with TCM treatment. One million randomly selected samples in the Taiwanese National Health Insurance Research Database between 1997 and 2008. Eighty-two thousand five hundred and fifty-one newly diagnosed urolithiasis patients. The correlation between TCM treatment, demographic factors, or medical conditions. A total of 62.6% of urolithiasis patients use TCM treatment. A younger age, female gender, polypharmacy, multiple comorbidities, and stone in the lower urinary tract result in a greater tendency to use TCM, after adjusting for demographic factors. Jia-Wei-Xiao-Yao-San Extract Powder and Ji-Sheng-Shen-Qi-Wan Extract Powder are the most frequently prescribed Chinese medicine formulae. This is the first study to examine the use of and the prescription pattern for TCM in urolithiasis patients using a random, national population-based sample. More than 62% of urolithiasis patients use TCM, and patients with polypharmacy, multiple comorbidities, and stone in the ureter are more likely to use TCM. The most frequently prescribed Chinese medicine formulae were Jia-Wei-Xiao-Yao-San Extract Powder and Ji-Sheng-Shen-Qi-Wan Extract Powder, which were reported to retard the progression of renal failure and alleviate flank pain or tenderness.

Structural and Spectral Characterization of Co2+- and Ni2+-DOPED CdO Powder Prepared From Solution at Room Temperature

NASA Astrophysics Data System (ADS)

Reddy, C. V.; Rao, L. V. Krishna; Satish, D. V.; Shim, J.; Ravikumar, R. V. S. S. N.

2015-11-01

The mild and simple solution method was used for the synthesis of Co2+- and Ni2+-doped CdO powders at room temperature. The prepared powders were characterized using powder X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), optical absorption, and Fourier transform infrared spectroscopy (FTIR). From the powder X-ray diffraction patterns, it has been observed that the prepared Co2+ and Ni2+ ion-doped CdO powders belong to the cubic phase, and the evaluated average crystalline sizes of the powders are 20 and 14 nm, respectively. The SEM images and the EDS spectra show that the prepared powders are distributed over different sizes in the grain boundaries. Optical absorption studies allow determination of site symmetry of the metal ion with its ligands. The crystal field (Dq) and inter-electronic repulsion (B and C) parameters have been evaluated from the optical absorption spectra. The FTIR spectra show the characteristic fundamental vibrations of the metal oxide and CdO.

Characterization of ceramic powders by an X-ray measuring method

NASA Technical Reports Server (NTRS)

Ziegler, B.

1983-01-01

X-ray line broadening analysis gives quantitative data on structural changes of ceramic powders after different processing steps. Various Al2O3 powders were investigated and the following points are discussed on the basis of these results: X-ray line broadening analysis, structural changes during grinding, structural changes during annealing, influence of structural properties on sintering behavior and application of line broadening analysis to quality control of powders.

Single-step laser deposition of functionally graded coating by dual ‘wire powder’ or ‘powder powder’ feeding—A comparative study

NASA Astrophysics Data System (ADS)

Syed, Waheed Ul Haq; Pinkerton, Andrew J.; Liu, Zhu; Li, Lin

2007-07-01

The creation of iron-copper (Fe-Cu) alloys has practical application in improving the surface heat conduction and corrosion resistance of, for example, conformal cooling channels in steel moulds, but is difficult to achieve because the elements have got low inter-solubility and are prone to solidification cracking. Previous work by these authors has reported a method to produce a graded iron-nickel-copper coating in a single-step by direct diode laser deposition (DLD) of nickel wire and copper powder as a combined feedstock. This work investigates whether dual powder feeds can be used in that process to afford greater geometric flexibility and compares attributes of the 'nickel wire and copper powder' and 'nickel powder and copper powder' processes for deposition on a H13 tool steel substrate. In wire-powder deposition, a higher temperature developed in the melt pool causing a clad with a smooth gradient structure. The nickel powder in powder-powder deposition did not impart much heat into the melt pool so the melt pool solidified with sharp composition boundaries due to single metal melting in some parts. In wire-powder experiments, a graded structure was obtained by varying the flow rates of wire and powder. However, a graded structure was not realised in powder-powder experiments by varying either the feed or the directions. Reasons for the differences and flow patterns in the melt pools and their effect on final part properties of parts produced are discussed.

Growth and characterization of organic NLO material: Clobetasol propionate

NASA Astrophysics Data System (ADS)

Purusothaman, R.; Rajesh, P.; Ramasamy, P.

2015-06-01

Single crystals of clobetasol propionate (CP) have been grown by slow evaporation solution technique using mixed solvent of methanol-acetone. The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm their lattice parameter and space group. The powder X-ray diffraction pattern of the grown CP has been indexed. Thermal analysis was performed to study the thermal stability of the grown crystals. Photoluminescence spectrum shows broad emission peak observed at 421 nm. Nonlinear optical studies were carried out for the grown crystal and second harmonic generation (SHG) efficiency was found in the crystal.

Characterization of cubic ceria?zirconia powders by X-ray diffraction and vibrational and electronic spectroscopy

NASA Astrophysics Data System (ADS)

Sánchez Escribano, Vicente; Fernández López, Enrique; Panizza, Marta; Resini, Carlo; Gallardo Amores, José Manuel; Busca, Guido

2003-10-01

The X-ray diffraction (XRD) patterns and the Infrared, Raman and UV-visible spectra of CeO 2ZrO 2 powders prepared by co-precipitation are presented. Raman spectra provide evidence for the largely predominant cubic structure of the powders with CeO 2 molar composition higher than 25%. Also skeletal IR spectra allow to distinguish cubic from tetragonal phases which are instead not easily distinguished on the basis of the XRD patterns. All mixed oxides including pure ceria are strong UV absorbers although also absorb in the violet visible region. By carefully selecting their composition and treatment temperature, the onset of the radiation that they cut off can be chosen in the 425-475 nm interval. Although they are likely metastable, the cubic phases are still pure even after heating at 1173 K for 4 h.

Crystal Structure of 17α-Dihydroequilin, C18H22O2, from Synchrotron Powder Diffraction Data and Density Functional Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James; Gindhart, Amy; Blanton, Thomas

The crystal structure of 17α-dihydroequilin has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. 17α-dihydroequilin crystallizes in space group P212121 (#19) with a = 6.76849(1) Å, b = 8.96849(1) Å, c = 23.39031(5) Å, V = 1419.915(3) Å3, and Z = 4. Both hydroxyl groups form hydrogen bonds to each other, resulting in zig-zag chains along the b-axis. The powder diffraction pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ as the entry 00-066-1608.

X-ray peak broadening analysis of AA 6061{sub 100-x} - x wt.% Al{sub 2}O{sub 3} nanocomposite prepared by mechanical alloying

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivasankaran, S., E-mail: sivasankarangs1979@gmail.com; Sivaprasad, K., E-mail: ksp@nitt.edu; Narayanasamy, R., E-mail: narayan@nitt.edu

2011-07-15

Nanocrystalline AA 6061 alloy reinforced with alumina (0, 4, 8, and 12 wt.%) in amorphized state composite powder was synthesized by mechanical alloying and consolidated by conventional powder metallurgy route. The as-milled and as-sintered (573 K and 673 K) nanocomposites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The peaks corresponding to fine alumina was not observed by XRD patterns due to amorphization. Using high-resolution transmission electron microscope, it is confirmed that the presence of amorphized alumina observed in Al lattice fringes. The crystallite size, lattice strain, deformation stress, and strain energy density of AA 6061 matrixmore » were determined precisely from the first five most intensive reflection of XRD using simple Williamson-Hall models; uniform deformation model, uniform stress deformation model, and uniform energy density deformation model. Among the developed models, uniform energy density deformation model was observed to be the best fit and realistic model for mechanically alloyed powders. This model evidenced the more anisotropic nature of the ball milled powders. The XRD peaks of as-milled powder samples demonstrated a considerable broadening with percentage of reinforcement due to grain refinement and lattice distortions during same milling time (40 h). The as-sintered (673 K) unreinforced AA 6061 matrix crystallite size from well fitted uniform energy density deformation model was 98 nm. The as-milled and as-sintered (673 K) nanocrystallite matrix sizes for 12 wt.% Al{sub 2}O{sub 3} well fitted by uniform energy density deformation model were 38 nm and 77 nm respectively, which indicate that the fine Al{sub 2}O{sub 3} pinned the matrix grain boundary and prevented the grain growth during sintering. Finally, the lattice parameter of Al matrix in as-milled and as-sintered conditions was also investigated in this paper. Research highlights: {yields} Integral breadth methods using various Williamson-Hall models were investigated for line profile analysis. {yields} Uniform energy density deformation model is observed to the best realistic model. {yields} The present analysis is used for understanding the stress and the strain present in the nanocomposites.« less

Increased cytokine production by monocytes from human subjects who consumed grape powder was not mediated by differences in dietary intake patterns

USDA-ARS?s Scientific Manuscript database

Recently, in a randomized, double-blind cross-over study, we reported that consumption of grape powder by obese human subjects increased the production of the pro-inflammatory cytokines interleukin-1' and interleukin-6 by ex vivo-derived peripheral blood monocytes after exposure to bacterial lipopol...

Magneto-structural studies of sol-gel synthesized nanocrystalline manganese substituted nickel ferrites

NASA Astrophysics Data System (ADS)

Pandav, R. S.; Patil, R. P.; Chavan, S. S.; Mulla, I. S.; Hankare, P. P.

2016-11-01

Nanocrystalline NiFe2-xMnxO4 (2≥x≥0) ferrites were prepared by sol-gel method. X-ray diffraction patterns reveal that synthesized compounds are in single phase cubic spinel lattice for all the composition. The surface morphology of all the samples were studied by scanning electron microscopy. The particle size measured from transmission electron microscopy and X-ray diffraction patterns confirms the nanosized dimension of the as-prepared powder. The elemental analysis was carried out by energy dispersive X-ray analysis technique. Magnetic properties such as saturation magnetization, coercivity and remanence are studied as a function of increasing Mn concentration at room temperature. The saturation magnetization shows a decreasing trend with increase in Mn content. The substitution of manganese in the nickel ferrite affects the structural and magnetic properties of cubic spinels.

Time resolved fluorescence of cow and goat milk powder

NASA Astrophysics Data System (ADS)

Brandao, Mariana P.; de Carvalho dos Anjos, Virgílio; Bell., Maria José V.

2017-01-01

Milk powder is an international dairy commodity. Goat and cow milk powders are significant sources of nutrients and the investigation of the authenticity and classification of milk powder is particularly important. The use of time-resolved fluorescence techniques to distinguish chemical composition and structure modifications could assist develop a portable and non-destructive methodology to perform milk powder classification and determine composition. This study goal is to differentiate milk powder samples from cows and goats using fluorescence lifetimes. The samples were excited at 315 nm and the fluorescence intensity decay registered at 468 nm. We observed fluorescence lifetimes of 1.5 ± 0.3, 6.4 ± 0.4 and 18.7 ± 2.5 ns for goat milk powder; and 1.7 ± 0.3, 6.9 ± 0.2 and 29.9 ± 1.6 ns for cow's milk powder. We discriminate goat and cow powder milk by analysis of variance using Fisher's method. In addition, we employed quadratic discriminant analysis to differentiate the milk samples with accuracy of 100%. Our results suggest that time-resolved fluorescence can provide a new method to the analysis of powder milk and its composition.

Structure-Property Relationships in W Doped (Ba,Sr)TiO(3) Thin Films Deposited by Pulsed Laser Deposition on (001) MgO

DTIC Science & Technology

2003-04-03

vacancies. The lattice of an oxygen * Permanent address - Nuclear Research Center- Negev (NRCN), Beer Sheva 9001, Israel. 41 deficient perovskite film...the film were determined by analysis of x-ray diffraction pattern using Cu K,, radiation from a Rigaku rotating anode source and a powder...thank Dr. H.S Kim, Mr. R.C.Y. Auyeung, Office of Naval Research, DARPA FAME and Nuclear Research Center- Negev . REFERENCES 1. J.S. Horwitz, D.B

The preparation of Zr-deuteride and phase stability studies of the Zr-D system

NASA Astrophysics Data System (ADS)

Maimaitiyili, T.; Steuwer, A.; Bjerkén, C.; Blomqvist, J.; Hoelzel, M.; Ion, J. C.; Zanellato, O.

2017-03-01

Deuteride phases in the zirconium-deuterium system in the temperature range 25-286 °C have been studied in-situ by high resolution neutron diffraction. The study primarily focused on observations of δ→γ transformation at 180 °C, and the peritectoid reaction α + δ ↔ γ at 255 °C in commercial grade Zr powder that was deuterated to a deuterium/Zr ratio of one to one. A detailed description of the zirconium deuteride preparation route by high temperature gas loading is also described. The lattice parameters of α-Zr, δ-ZrDx and ε-ZrDx were determined by whole pattern crystal structure analysis, using Rietveld and Pawley refinements, and are in good agreement with values reported in the literature. The controversial γ-hydride phase was observed both in-situ and ex-situ in deuterated Zr powder after a heat treatment at 286 °C and slow cooling.

Novel perovskite coating of strontium zirconate in Inconel substrate

NASA Astrophysics Data System (ADS)

Venkatesh, G.; Blessto, B.; Rao, C. Santhosh Kumar; Subramanian, R.; Berchmans, L. John

2018-02-01

Thermal Barrier Coatings (TBC) provides a low thermal conductivity barrier to heat transfer from the hot gas in the engine to the surface of the coated alloy component. SrZrO3 powder are prepared by Sol Gel synthesis method. The synthesized powder sample is characterized by X Ray Diffraction Technique (XRD), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) and the results are interpreted. The Polycrystalline nature of SrZrO3 is confirmed and lattice spacing are determined in XRD. SEM shows sub-micron sized particles and a fringed pattern is observed in TEM. The IN718 specimen is Wire Cut and Sand Blasted. A SrZrO3 double layer is coated over the Inconel specimen through a Bond Coat made of NiCoCrAlY by Plasma spraying Process and also characterized. SEM analysis of the Coating shows diffusion of Fe, Sr into the substrate.

Synthesis, characterization, photoluminescence, and electrochemical studies of novel mononuclear Cu(II) and Zn(II) complexes with the 1-benzylimidazolium ligand

NASA Astrophysics Data System (ADS)

Bibi, Sherino; Mohammad, Sharifah; Manan, Ninie Suhana Abdul; Ahmad, Jimmy; Kamboh, Muhammad Afzal; Khor, Sook Mei; Yamin, Bohari M.; Abdul Halim, Siti Nadiah

2017-08-01

Two new mononuclear coordination complexes [Cu(bim)4Cl2]ṡ2H2O (1) and [Zn(bim)2Cl2] (2) containing the 1-benzylimidazole (bim) ligand were successfully synthesized. Both complexes were characterized by IR, UV-vis, and fluorescence spectroscopies, single crystal and powder X-ray diffraction measurements, and thermogravimetric analysis. Self-assembly during the recrystallization process resulted in the formation of octahedral and tetrahedral Cu(II) and Zn(II) complexes, respectively. The single crystals obtained are representative of the bulk material, as shown by the powder X-ray diffraction patterns. Cyclic voltammetry measurements showed that complex 1 undergoes a quasi-reversible redox reaction, while complex 2 undergoes reduction alone, and no oxidation peak was observed; this is due to the stability of the reduced form of complex 2.

Calculating cellulose diffraction patterns

USDA-ARS?s Scientific Manuscript database

Although powder diffraction of cellulose is a common experiment, the patterns are not widely understood. The theory is mathematical, there are numerous different crystal forms, and the conventions are not standardized. Experience with IR spectroscopy is not directly transferable. An awful error, tha...

Nuclear forensic analysis of an unknown uranium ore concentrate sample seized in a criminal investigation in Australia

DOE PAGES

Keegan, Elizabeth; Kristo, Michael J.; Colella, Michael; ...

2014-04-13

In early 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. While searching the laboratory, they discovered a small glass jar labelled “Gamma Source” and containing a green powder. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterize and identify the material and determine its provenance. Isotopic and impurity content, phase composition, microstructure and other characteristics were measured on the seized sample, and the results were compared with similar material obtained from the suspected source (ore and ore concentrate material). While an extensive rangemore » of parameters were measured, the key ‘nuclear forensic signatures’ used to identify the material were the U isotopic composition, Pb and Sr isotope ratios, and the rare earth element pattern. These measurements, in combination with statistical analysis of the elemental and isotopic content of the material against a database of uranium ore concentrates sourced from mines located worldwide, led to the conclusion that the seized material (a uranium ore concentrate of natural isotopic abundance) most likely originated from Mary Kathleen, a former Australian uranium mine.« less

Nuclear forensic analysis of an unknown uranium ore concentrate sample seized in a criminal investigation in Australia.

PubMed

Keegan, Elizabeth; Kristo, Michael J; Colella, Michael; Robel, Martin; Williams, Ross; Lindvall, Rachel; Eppich, Gary; Roberts, Sarah; Borg, Lars; Gaffney, Amy; Plaue, Jonathan; Wong, Henri; Davis, Joel; Loi, Elaine; Reinhard, Mark; Hutcheon, Ian

2014-07-01

Early in 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. During the search of the laboratory, a small glass jar labelled "Gamma Source" and containing a green powder was discovered. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterise and identify the material and determine its provenance. Isotopic and impurity content, phase composition, microstructure and other characteristics were measured on the seized sample, and the results were compared with similar material obtained from the suspected source (ore and ore concentrate material). While an extensive range of parameters were measured, the key 'nuclear forensic signatures' used to identify the material were the U isotopic composition, Pb and Sr isotope ratios, and the rare earth element pattern. These measurements, in combination with statistical analysis of the elemental and isotopic content of the material against a database of uranium ore concentrates sourced from mines located worldwide, led to the conclusion that the seized material (a uranium ore concentrate of natural isotopic abundance) most likely originated from Mary Kathleen, a former Australian uranium mine. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Nuclear forensic analysis of an unknown uranium ore concentrate sample seized in a criminal investigation in Australia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keegan, Elizabeth; Kristo, Michael J.; Colella, Michael

In early 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. While searching the laboratory, they discovered a small glass jar labelled “Gamma Source” and containing a green powder. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterize and identify the material and determine its provenance. Isotopic and impurity content, phase composition, microstructure and other characteristics were measured on the seized sample, and the results were compared with similar material obtained from the suspected source (ore and ore concentrate material). While an extensive rangemore » of parameters were measured, the key ‘nuclear forensic signatures’ used to identify the material were the U isotopic composition, Pb and Sr isotope ratios, and the rare earth element pattern. These measurements, in combination with statistical analysis of the elemental and isotopic content of the material against a database of uranium ore concentrates sourced from mines located worldwide, led to the conclusion that the seized material (a uranium ore concentrate of natural isotopic abundance) most likely originated from Mary Kathleen, a former Australian uranium mine.« less

The synthesis of nanostructured SiC from waste plastics and silicon powder

NASA Astrophysics Data System (ADS)

Ju, Zhicheng; Xu, Liqiang; Pang, Qiaolian; Xing, Zheng; Ma, Xiaojian; Qian, Yitai

2009-09-01

Waste plastics constitute a growing environmental problem. Therefore, the treatment of waste plastics should be considered. Here we synthesize 3C-SiC nanomaterials coexisting with amorphous graphite particles utilizing waste plastics and Si powder at 350-500 °C in a stainless steel autoclave. 3C-SiC could be finally obtained after refluxing with aqueous HClO4 (70 wt%) at 180 °C. X-ray powder diffraction patterns indicate that the product is 3C-SiC with the calculated lattice constant a = 4.36 Å. Transmission electron microscopy (TEM) images show that the SiC samples presented two morphologies: hexagonal platelets prepared by the waste detergent bottles or beverage bottles and nanowires prepared by waste plastic bags respectively. The corresponding selected area electron diffraction (SAED) pattern indicates that either the entire hexagonal platelet or the nanowire is single crystalline. High-resolution TEM shows the planar surfaces of the SiC platelet correspond to {111} planes; the lateral surfaces are {110} planes and the preferential growth direction of the nanowires is along [111]. The output of SiC was ~39% based on the amount of Si powder.

In vitro bioactivity and antimicrobial tuning of bioactive glass nanoparticles added with neem (Azadirachta indica) leaf powder.

PubMed

Prabhu, M; Ruby Priscilla, S; Kavitha, K; Manivasakan, P; Rajendran, V; Kulandaivelu, P

2014-01-01

Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications.

In Vitro Bioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder

PubMed Central

Prabhu, M.; Ruby Priscilla, S.; Kavitha, K.; Manivasakan, P.; Rajendran, V.; Kulandaivelu, P.

2014-01-01

Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications. PMID:25276834

Effect on dielectric, magnetic, optical and structural properties of Nd-Co substituted barium hexaferrite nanoparticles

NASA Astrophysics Data System (ADS)

Kaur, Talwinder; Kumar, Sachin; Bhat, Bilal Hamid; Want, Basharat; Srivastava, A. K.

2015-06-01

M-type barium hexaferrite [Ba1- x Nd x Co x Fe12- x O19 ( x = 0.0-0.5) (BNCM)] powders, synthesized using citrate precursor method, were heat treated at 900 °C for 5 h. The pattern of powders, when subjected to X-ray diffraction, shows the formation of M-type hexaferrite phase. The formation of BNCM, from thermogravimetric analysis/differential thermal analysis/derivative thermogravimetry, is observed to be at 440 °C. The presence of two prominent peaks near 430 and 580 cm-1 in Fourier transform infrared spectroscopy spectra indicates the formation of M-type hexaferrites. The M- H curves obtained from vibrating sample magnetometer were used to calculate saturation magnetization ( M S), retentivity ( M R), squareness ration and coercivity ( H C). UV-Vis NIR spectroscopy reveals that band gap depends on size of the crystallites. The dielectric constant is found to be high at low frequency and decreases with increase in frequency. This kind of behaviour is explained on the basis of Koop's phenomenological theory and Maxwell-Wagner theory.

Functional biocompatible magnetite-cellulose nanocomposite fibrous networks: Characterization by fourier transformed infrared spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy analysis.

PubMed

Habibi, Neda

2015-02-05

The preparation and characterization of functional biocompatible magnetite-cellulose nano-composite fibrous material is described. Magnetite-cellulose nano-composite was prepared by a combination of the solution-based formation of magnetic nano-particles and subsequent coating with amino celluloses. Characterization was accomplished using X-ray powder diffraction (XRD), fourier transformed infrared (FTIR) and field emission scanning electron microscopy (FESEM) analysis. The peaks of Fe3O4 in the XRD pattern of nanocomposite confirm existence of the nanoparticles in the amino cellulose matrix. Magnetite-cellulose particles exhibit an average diameter of roughly 33nm as demonstrated by field emission scanning electron microscopy. Magnetite nanoparticles were irregular spheres dispersed in the cellulose matrix. The vibration corresponding to the NCH3 functional group about 2850cm(-1) is assigned in the FTIR spectra. Functionalized magnetite-cellulose nano-composite polymers have a potential range of application as targeted drug delivery system in biomedical field. Copyright © 2014 Elsevier B.V. All rights reserved.

Spectrochemical analysis of powder using 355 nm Nd-YAG laser-induced low-pressure plasma.

PubMed

Lie, Zener S; Pardede, M; Hedwig, R; Suliyanti, M M; Kurniawan, Koo Hendrik; Munadi; Lee, Yong-Inn; Kagawa, Kiichiro; Hattori, Isamu; Tjia, May On

2008-04-01

The applicability of spectrochemical analysis of minute amounts of powder samples was investigated using an ultraviolet Nd-YAG laser (355 nm) and low-pressure ambient air. A large variety of chemical powder samples of different composition were employed in the experiment. These included a mixture of copper(II) sulfate pentahydrate, zinc sulfide, and chromium(III) sulfate n-hydrate powders, baby powder, cosmetic powders, gold films, zinc supplement tablet, and muds and soils from different areas. The powder samples were prepared by pulverizing the original samples to an average size of around 30 microm in order to trap them in the tiny micro holes created on the surface of the quartz subtarget. It was demonstrated that in all cases studied, good quality spectra were obtained with low background, free from undesirable contamination by the subtarget elements and featuring ppm sensitivity. A further measurement revealed a linear calibration curve with zero intercept. These results clearly show the potential application of this technique for practical qualitative and quantitative spectrochemical analysis of powder samples in various fields of study and investigation.

Using Two Different Approaches to Assess Dietary Patterns: Hypothesis-Driven and Data-Driven Analysis.

PubMed

Previdelli, Ágatha Nogueira; de Andrade, Samantha Caesar; Fisberg, Regina Mara; Marchioni, Dirce Maria

2016-09-23

The use of dietary patterns to assess dietary intake has become increasingly common in nutritional epidemiology studies due to the complexity and multidimensionality of the diet. Currently, two main approaches have been widely used to assess dietary patterns: data-driven and hypothesis-driven analysis. Since the methods explore different angles of dietary intake, using both approaches simultaneously might yield complementary and useful information; thus, we aimed to use both approaches to gain knowledge of adolescents' dietary patterns. Food intake from a cross-sectional survey with 295 adolescents was assessed by 24 h dietary recall (24HR). In hypothesis-driven analysis, based on the American National Cancer Institute method, the usual intake of Brazilian Healthy Eating Index Revised components were estimated. In the data-driven approach, the usual intake of foods/food groups was estimated by the Multiple Source Method. In the results, hypothesis-driven analysis showed low scores for Whole grains, Total vegetables, Total fruit and Whole fruits), while, in data-driven analysis, fruits and whole grains were not presented in any pattern. High intakes of sodium, fats and sugars were observed in hypothesis-driven analysis with low total scores for Sodium, Saturated fat and SoFAA (calories from solid fat, alcohol and added sugar) components in agreement, while the data-driven approach showed the intake of several foods/food groups rich in these nutrients, such as butter/margarine, cookies, chocolate powder, whole milk, cheese, processed meat/cold cuts and candies. In this study, using both approaches at the same time provided consistent and complementary information with regard to assessing the overall dietary habits that will be important in order to drive public health programs, and improve their efficiency to monitor and evaluate the dietary patterns of populations.

Sol-gel synthesis and characterizations of crystalline NaGd(WO4)2 powder for anisotropic transparent ceramic laser application

NASA Astrophysics Data System (ADS)

Durairajan, A.; Thangaraju, D.; Balaji, D.; Moorthy Babu, S.

2013-02-01

NaGd(WO4)2 powders were synthesized at different pH (3.5, 4.5, 5.5, 6.5 and 7.5) values by conventional Pechini method. Sodium and gadolinium nitrate salts and ammonium paratungstate are used as starting precursors. Metal cations were chelated by citric acid and individual citrates were bound together with ethylene glycol. Synthesized gel was analyzed using differential thermal analysis (DTA), thermo gravimetric (TG) and FT-IR spectroscopy to understand the degradation of gel and formation of metal citrates. Calcined powders (250, 600, 700 and 800 °C) were characterized by powder XRD, FT-IR, Raman and FE-SEM analysis. The temperature dependent phase formation was examined by powder XRD. The morphological changes at different pH derived powders were observed with FE-SEM micrographs. Stepwise organic liberation with respect to temperature and presence of carbon content in the pre-fired powder were analyzed using FT-IR analysis. Raman spectrum reveals disordered tungstate vibrations in the NGW matrix.

Evaluation of Rock Powdering Methods to Obtain Fine-grained Samples for CHEMIN, a Combined XRD/XRF Instrument

NASA Technical Reports Server (NTRS)

Chipera, S. J.; Vaniman, D. T.; Bish, D. L.; Sarrazin, P.; Feldman, S.; Blake, D. F.; Bearman, G.; Bar-Cohen, Y.

2004-01-01

A miniature XRD/XRF (X-ray diffraction / X-ray fluorescence) instrument, CHEMIN, is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed to enable remote XRD analysis is how best to obtain a representative sample powder for analysis. For powder XRD analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a two-dimensional detector as used in the CHEMIN instrument will produce good results even with poorly prepared powder, the quality of the data will improve and the time required for data collection will be reduced if the sample is fine-grained and randomly oriented. A variety of methods have been proposed for XRD sample preparation. Chipera et al. presented grain size distributions and XRD results from powders generated with an Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL. The USDC was shown to be an effective instrument for sampling rock to produce powder suitable for XRD. In this paper, we compare powder prepared using the USDC with powder obtained with a miniaturized rock crusher developed at JPL and with powder obtained with a rotary tungsten carbide bit to powders obtained from a laboratory bench-scale Retsch mill (provides benchmark mineralogical data). These comparisons will allow assessment of the suitability of these methods for analysis by an XRD/XRF instrument such as CHEMIN.

Silica in Opal at Buckskin and Greenhorn on Mount Sharp

NASA Image and Video Library

2015-12-17

This graph presents information from the NASA Curiosity Mars rover's onboard analysis of rock powder drilled from the "Buckskin" and "Greenhorn" target locations on lower Mount Sharp. Buckskin, in the "Marias Pass" area, and Greenhorn, in the "Bridger Basin" area, both contain high concentrations of silica. X-ray diffraction analysis of powered samples inside Curiosity's Chemistry and Mineralogy (CheMin) instrument revealed that each of them contains silica in the form of noncrystalline opal. The broad hump in the two X-ray diffraction patterns is diagnostic of opaline silica. Some of the silica in Buckskin is in the form of tridymite. http://photojournal.jpl.nasa.gov/catalog/PIA20273

Directional pair distribution function for diffraction line profile analysis of atomistic models

PubMed Central

Leonardi, Alberto; Leoni, Matteo; Scardi, Paolo

2013-01-01

The concept of the directional pair distribution function is proposed to describe line broadening effects in powder patterns calculated from atomistic models of nano-polycrystalline microstructures. The approach provides at the same time a description of the size effect for domains of any shape and a detailed explanation of the strain effect caused by the local atomic displacement. The latter is discussed in terms of different strain types, also accounting for strain field anisotropy and grain boundary effects. The results can in addition be directly read in terms of traditional line profile analysis, such as that based on the Warren–Averbach method. PMID:23396818

Synthesis and characterization of NiO nanopowder by sol-gel process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ningsih, Sherly Kasuma Warda

2015-09-30

Preparation of nickel oxide (NiO) nanopowder by sol-gel process has been studied. NiO nanopowders were obtained by sol-gel method by using nickel nitrate hexahydrate and sodium hydroxide and aquadest were used as precursor, agent precipitator and solvent, respectively. The powders were formed by drying at 110°C and followed by heating in the furnace at 400°C for 1.5 hours. The product was obtained black powder. The product was characterized by Energy Dispesive X-ray Fluorescence (ED-XRF), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The ED-XRF pattern shows the composition of NiO produced was 97.1%. The XRD pattern showed NiO forms weremore » produced generally in monoclinic stucture. The crystalline size of NiO was obtained in the range 40-85 nm. SEM micrograph clearly showed that powder had a spherical with uniform distribution size is 0.1-1.0 µm approximately.« less

On the formation features, microstructure and microhardness of single laser tracks formed by laser cladding of a NiCrBSi self-fluxing alloy

NASA Astrophysics Data System (ADS)

Devojno, O. G.; Feldshtein, E.; Kardapolava, M. A.; Lutsko, N. I.

2018-07-01

In the present paper, the influence of laser cladding conditions on the powder flow conditions, as well as the microstructure, phases and microhardness of an Ni-based self-fluxing alloy coating are described. The optimal granulations of a self-fluxing alloy powder and the relationship between the flow of powder of various fractions and the flow rate and pressure of the transporting gas have been determined. The laser beam speed, track pitch and the distance from the nozzle to the coated surface influence the height and width of single tracks. Regularities in the formation of microstructure under different cladding conditions are defined, as well as regularity of distribution of elements over the track depth and in the transient zone. The patterns of microhardness distribution over the track depth for different cladding conditions are found. These patterns as well as the optimal laser spot pitch allowed obtaining a uniform cladding layer.

Texture and quality properties of Chinese fresh egg noodles formulated with green seaweed (Monostroma nitidum) powder.

PubMed

Chang, H C; Wu, L-C

2008-10-01

The objective of this study was to compare fresh Chinese noodles made with different levels of green seaweed. Green seaweed powder was incorporated in proportions of 4%, 6%, and 8% in noodles, which were made with or without additional eggs. Proximate compositions, cooking properties, textural intensities, and sensory qualities of noodles were assessed. The addition of seaweed powder increased the crude fiber contents of raw fresh noodles; the fiber contents were 0.100%+/- 0.015 to 0.449%+/- 0.013 for noodles made with eggs from 0% to 8% additional seaweed and 0.247%+/- 0.018 to 0.344%+/- 0.021 for those without eggs. Higher cooking yields were found in the noodles, due to water absorption during cooking by the fibers and polysaccharides in the seaweed. Significantly higher cooking yields (P < 0.05) were found in the noodles with 8% additional seaweed powder; water uptake readings measured 2.39 +/- 0.38 and 2.43 +/- 0.25 g H(2)O/g noodle for samples made without and with eggs, respectively. Higher water absorption by the seaweed led to softer and spongier textural intensities in the noodles. Breaking energy of cooked fresh egg noodles were 28.94 +/- 3.42 to 6.43 +/- 1.01 N x mm for 8% to 0% additional seaweed, and the intensities decreased as the amount of seaweed increased; the same pattern was observed in noodles without eggs, where readings were 8.66 +/- 1.02 to 3.49 +/- 0.25 N x mm. Capacities of extensibility measured 61.81 +/- 2.04 to 30.74 +/- 0.90 mm for fresh egg noodles with additional seaweed powder from 0% to 8%, and 47.46 +/- 2.41 to 28.36 +/- 2.25 mm for cooked fresh noodles without eggs. The results from Pearson's correlation analysis indicated that textural parameters were influenced not only by additional eggs and seaweed powder, but also by cooking properties.

Modeling of the Effect of Path Planning on Thermokinetic Evolutions in Laser Powder Deposition Process

NASA Astrophysics Data System (ADS)

Foroozmehr, Ehsan; Kovacevic, Radovan

2011-07-01

A thermokinetic model coupling finite-element heat transfer with transformation kinetics is developed to determine the effect of deposition patterns on the phase-transformation kinetics of laser powder deposition (LPD) process of a hot-work tool steel. The finite-element model is used to define the temperature history of the process used in an empirical-based kinetic model to analyze the tempering effect of the heating and cooling cycles of the deposition process. An area is defined to be covered by AISI H13 on a substrate of AISI 1018 with three different deposition patterns: one section, two section, and three section. The two-section pattern divides the area of the one-section pattern into two sections, and the three-section pattern divides that area into three sections. The results show that dividing the area under deposition into smaller areas can influence the phase transformation kinetics of the process and, consequently, change the final hardness of the deposited material. The two-section pattern shows a higher average hardness than the one-section pattern, and the three-section pattern shows a fully hardened surface without significant tempered zones of low hardness. To verify the results, a microhardness test and scanning electron microscope were used.

Detection and original dose assessment of egg powders subjected to gamma irradiation by using ESR technique

NASA Astrophysics Data System (ADS)

Aydın, Talat

2015-09-01

ESR (electron spin resonance) techniques were applied for detection and original dose estimation to radiation-processed egg powders. The un-irradiated (control) egg powders showed a single resonance line centered at g=2.0086±0.0005, 2.0081±0.0005, 2.0082±0.0005 (native signal) for yolk, white and whole egg, respectively. Irradiation induced at least one additional intense singlet overlapping to the control signal and caused a significant increase in signal intensity without any changes in spectral patterns. Responses of egg powders to different gamma radiation doses in the range 0-10 kGy were examined. The stability of the radiation-induced ESR signal of irradiated egg powders were investigated over a storage period of about 5 months. Additive reirradiation of the egg powders produces a reproducible dose response function, which can be used to assess the initial dose by back-extrapolation. The additive dose method gives an estimation of the original dose within ±12% at the end of the 720 h storage period.

Effect of amylose, particle size & morphology on the functionality of starches of traditional rice cultivars.

PubMed

Bhat, Farhan Mohiuddin; Riar, Charanjit Singh

2016-11-01

The research was carried out to investigate the effect of starch powder particle size, morphology, amylose content and varietal effect on physicochemical, X-ray diffraction pattern, thermal and pasting characteristics. The results indicated that starches isolated from seven traditional rice cultivars of temperate region of India have possessed higher yield (82.47-86.83%) with lower degree of granule damage and higher level of starch crystallinity (36.55-39.15%). The water and oil binding capacities were observed to correlate positively with amylose content. The bulk density and color parameters of starches were found to have linked with starch powder particle size coupled with arrangement and morphology of the starch granules. The rice cultivars having smaller starch powder particle size indicated lowest degree of crystallinity. Morphological studies revealed that the starches with tightly packed granules had greater mean granular width, while granules with openly spaced granular morphology depicted the higher values for mean granular length. The peak height index (PHI) among different starches ranged from 1.01 to 2.57 whereas the gelatinization range varied from 10.66 to 10.88. Concluding, the differences in distributional pattern of starch granule size and shape and powder particle size indicated a significant effect on the functional properties of starch. Copyright © 2016 Elsevier B.V. All rights reserved.

Crystal structure of hydrocortisone acetate, C23H32O6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James A.; Gindhart, Amy M.; Blanton, Thomas N.

The crystal structure of hydrocortisone acetate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Hydrocortisone acetate crystallizes in space groupP2 1(#4) witha= 8.85173(3) Å,b= 13.53859(3) Å,c= 8.86980(4) Å,β= 101.5438(3)°,V= 1041.455(6) Å 3, andZ= 2. Both hydroxyl groups form hydrogen bonds to the ketone oxygen atom on the steroid ring system, resulting in a three-dimensional hydrogen bond network. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

Characterization of Metal Powders Used for Additive Manufacturing.

PubMed

Slotwinski, J A; Garboczi, E J; Stutzman, P E; Ferraris, C F; Watson, S S; Peltz, M A

2014-01-01

Additive manufacturing (AM) techniques can produce complex, high-value metal parts, with potential applications as critical parts, such as those found in aerospace components. The production of AM parts with consistent and predictable properties requires input materials (e.g., metal powders) with known and repeatable characteristics, which in turn requires standardized measurement methods for powder properties. First, based on our previous work, we assess the applicability of current standardized methods for powder characterization for metal AM powders. Then we present the results of systematic studies carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to structure and chemistry, including X-ray diffraction, energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, and X-Ray photoelectron spectroscopy were also employed. The results of these analyses show how virgin powder changes after being exposed to and recycled from one or more Direct Metal Laser Sintering (DMLS) additive manufacturing build cycles. In addition, these findings can give insight into the actual additive manufacturing process.

Defect Control of the WC Hardmetal by Mixing Recycled WC Nano Powder and Tungsten Powder

NASA Astrophysics Data System (ADS)

Hur, Man Gyu; Shin, Mi Kyung; Kim, Deug Joong; Yoon, Dae Ho

2018-03-01

Tungsten metal powder was added to recycled WC nano powder to control the macro and micro defects of WC hardmetal. The macro and micro defects caused by the excess carbon in the recycled WC powder were markedly removed after the addition of tungsten metal powder ranging from 2 to 6 wt%. The density and hardness of the WC hardmetals also increased due to the removal of defects after adding the tungsten metal powder. The density and hardness of WC hardmetals with the addition of W metal powder ranged from 8 to 12 wt% increased linearly as the W metal powder content increased due to the formation of a new (Co- and W-rich WC) composition. The surface morphology of the WC hardmetals was observed via field emission scanning electron microscopy, and a quantitative elemental analysis was conducted via X-ray fluorescence spectrometry and energy dispersive X-ray analysis. The density and hardness of the WC hardmetals were respectively measured using an analytical balance and a Vikers hardness tester. The effect on the defects in the recycled WC hardmetals through the addition of the tungsten metal powder was discussed in detail.

Metal-Assisted Laser-Induced Gas Plasma for the Direct Analysis of Powder Using Pulse CO2 Laser

NASA Astrophysics Data System (ADS)

Khumaeni, A.; Lie, Z. S.; Kurniawan, K. H.; Kagawa, K.

2017-01-01

Analysis of powder samples available in small quantities has been carried out using metal-assisted gas plasma by utilizing a transversely excited atmospheric (TEA) CO2 laser. The powder was homogeneously mixed with Si grease, and the mixed powder was painted on a metal subtarget. When a TEA CO2 laser was directly focused on the metal subtarget at atmospheric pressure of He gas, a high-temperature He gas plasma was induced. It is assumed that the powder particles were vaporized to be effectively atomized and excited in the gas plasma region. This method has been employed in the rapid analyses of elements in organic and inorganic powder samples present in small quantities. Detection of trace elements of Cr and Pb has been successfully made by using the supplement powder and loam soil, respectively. The detection limits of Pb in loam soil were approximately 20 mg/kg.

Thermal stability of a modified sol-gel derived hydroxyapatite nanopowders

NASA Astrophysics Data System (ADS)

Herradi, S.; El Bali, B.; Khaldi, M.; Lachkar, M.

2017-03-01

Hydroxyapatite Ca10(PO4)6(OH)2 (HA) powder was successfully synthesized by a modified sol-gel method using a solution of calcium nitrate in ethanol, along with a solution of diammonium hydrogen phosphate in water and NH4OH as starting materials. The Ca/P molar ratio was maintained at 1.67. The powder was subjected to furnace and microwave heating to compare the decomposition of HA and study the crystallite sizes. It was found that microwave heated powders were pure HAP up to 230°C with absence of secondary phases. However, XRD patterns show that furnace heated powders convert completely to β-TCP when treated at 750°C and 1000°C. This result was confirmed by the absence of hydroxyl bands in the FT-IR spectra for these temperatures.

Phase analysis of ZrO2-SiO2 systems synthesized through Ball milling mechanical activations

NASA Astrophysics Data System (ADS)

Nurlaila, Rizka; Musyarofah, Muwwaqor, Nibras Fuadi; Triwikantoro, Kuswoyo, Anton; Pratapa, Suminar

2017-01-01

Zircon powders have been produced from raw materials of amorphous zirconia and amorphous silica powders obtained from natural zircon sand of Kalimantan Tengah, Indonesia. Synthesis process was started with the extraction of zircon powder to produce sodium silicate solution and pure zircon powder. The amorphous zirconia and silica powders were prepared by alkali fusion and co-precipitation techniques. The powders were mixed using a planetary ball mill, followed by a calcination of various holding time of 3, 10, and 15 h. Phase characterization was done using X-Ray Diffraction (XRD) technique and analysis of the diffraction data was carried out using Rietica and MAUD software. The identified phases after the calcination were zircon, tetragonal zirconia, and cristobalite. The highest zircon content was obtained in the sample calcinated for15 hours - reaching 99.66 %wt. Crystallite size analysis revealed that the samples calcinated for 3, 10, and 15 h exhibited zircon crystal size of 176 (1) nm, 191 (1) nm and 233 (1) nm respectively.

Role of initial heat treatment of the ferrite component on magnetic properties in the composite of ferrimagnetic Co1.75Fe1.25O4 ferrite and non-magnetic BaTiO3 oxide

NASA Astrophysics Data System (ADS)

Bhowmik, R. N.; Kazhugasalamoorthy, S.; Sinha, A. K.

2017-12-01

We have prepared a composite of ferrimagnetic ferrite Co1.75Fe1.25O4 and non-magnetic oxide BaTiO3. The ferrite composition Co1.75Fe1.25O4 has been prepared by chemical co-precipitation and subsequently heated at different temperatures. The heat treated ferrite powder has been mixed with BaTiO3 powder with mass ratio 1:1 and the mixed powder has been finally heated at 1000 °C to form composite material. Structural phase of the composite material has been confirmed by high quality Synchrotron X-ray diffraction pattern and Micro-Raman spectra. The grain surface morphology and elemental composition have been studied by Scanning electron microscope and Energy dispersive X-ray analysis. The distribution of magnetic exchange interactions and blocking behavior of the ferrimagnetic grains in composite samples has been understood by analyzing the temperature and magnetic field dependence of dc magnetization. Finally, information on modified micro-structure and ferrimagnetic parameters in composite samples has been obtained as the variation of annealing temperature of the ferrite component before making composite.

Ballistic Characterization of the Scalability of Magnesium Alloy AMX602

DTIC Science & Technology

2015-07-01

Powder Metallurgy 4 5. Fabrication Procedure 4 6. Mechanical Property Analysis 5 7. Ballistic Experimental Procedures 6 8. Ballistic Experimental...compositions of noncombustive Mg alloy powders 4. Powder Metallurgy The powder was consolidated at room temperature using a 2,000-kN hydraulic press...evaluation of advanced powder metallurgy magnesium alloys for dynamic applications. Aberdeen Proving Ground (MD): Army Research Laboratory (US); 2009 May

[Isolation and identification of Cronobacter (Enterobacter sakazakii) strains from food].

PubMed

Dong, Xiaohui; Li, Chengsi; Wu, Qingping; Zhang, Jumei; Mo, Shuping; Guo, Weipeng; Yang, Xiaojuan; Xu, Xiaoke

2013-05-04

This study aimed to detect and quantify Cronobacter in 300 powdered milk samples and 50 non-powdered milk samples. Totally, 24 Cronobacter (formerly Enterobacter sakazakii) strains isolated from powdered milk and other foods were identified and confirmed. Cronobacter strains were detected quantitatively using most probable number (MPN) method and molecular detection method. We identified 24 Cronobacter strains using biochemical patterns, including indole production and dulcitol, malonate, melezitose, turanose, and myo-Inositol utilization. Of the 24 strains, their 16S rRNA genes were sequenced, and constructed phylogenetic tree by N-J (Neighbour-Joining) with the 16S rRNA gene sequences of 17 identified Cronobacter strains and 10 non-Cronobacter strains. Quantitative detection showed that Cronobacter strains were detected in 23 out of 350 samples yielding 6.6% detection rate. Twenty-four Cronobacter strains were isolated from 23 samples and the Cronobacter was more than 100 MPN/100g in 4 samples out of 23 samples. The 24 Cronobacter spp. isolates strains were identified and confirmed, including 19 Cronobacter sakazakii strains, 2 C. malonaticus strains, 2 C. dubliensis subsp. lactaridi strains, and 1 C. muytjensii strain. The combination of molecular detection method and most probable number (MPN) method could be suitable for the detection of Cronobacter in powdered milk, with low rate of contamination and high demand of quantitative detection. 24 isolated strains were confirmed and identified by biochemical patterns and molecular technology, and C. sakazakii could be the dominant species. The problem of Cronobacter in powdered milk should be a hidden danger to nurseling, and should catch the government and consumer's attention.

Solid-state NMR and IR for the analysis of pharmaceutical solids: polymorphs of fosinopril sodium.

PubMed

Brittain, H G; Morris, K R; Bugay, D E; Thakur, A B; Serajuddin, A T

1993-01-01

The two polymorphic modifications of fosinopril sodium have been characterized as to their differences in melting behaviour, powder X-ray diffraction patterns, Fourier transform infrared spectra (FTIR), and solid-state 31P- and 13C-NMR spectra. The polymorphs were found to be enantiotropically related based upon melting point, heat of fusion, and solution mediated transformation data. Analysis of the solid-state FTIR and 13C-NMR data indicated that the environment of the acetal side chain of fosinopril sodium differed in two polymorphs, and that there might be cis-trans isomerization about the C6-N peptide bond. These conformational differences are postulated as the origin of the observed polymorphism.

Curcumin phytosomal softgel formulation: Development, optimization and physicochemical characterization.

PubMed

Allam, Ahmed N; Komeil, Ibrahim A; Abdallah, Ossama Y

2015-09-01

Curcumin, a naturally occurring lipophilic molecule can exert multiple and diverse bioactivities. However, its limited aqueous solubility and extensive presystemic metabolism restrict its bioavailability. Curcumin phytosomes were prepared by a simple solvent evaporation method where free flowing powder was obtained in addition to a newly developed semisolid formulation to increase curcumin content in softgels. Phytosomal powder was characterized in terms of drug content and zeta potential. Thirteen different softgel formulations were developed using oils such as Miglyol 812, castor oil and oleic acid, a hydrophilic vehicle such as PEG 400 and bioactive surfactants such as Cremophor EL and KLS P 124. Selected formulations were characterized in terms of curcumin in vitro dissolution. TEM analysis revealed good stability and a spherical, self-closed structure of curcumin phytosomes in complex formulations. Stability studies of chosen formulations prepared using the hydrophilic vehicle revealed a stable curcumin dissolution pattern. In contrast, a dramatic decrease in curcumin dissolution was observed in case of phytosomes formulated in oily vehicles.

[Advances in studies on bear bile powder].

PubMed

Zhou, Chao-fan; Gao, Guo-jian; Liu, Ying

2015-04-01

In this paper, a detailed analysis was made on relevant literatures about bear bile powder in terms of chemical component, pharmacological effect and clinical efficacy, indicating bear bile powder's significant pharmacological effects and clinical application in treating various diseases. Due to the complex composition, bear bile powder is relatively toxic. Therefore, efforts shall be made to study bear bile powder's pharmacological effects, clinical application, chemical composition and toxic side-effects, with the aim to provide a scientific basis for widespread reasonable clinical application of bear bile powder.

FGM (Functionally Graded Material) Thermal Barrier Coatings for Hypersonic Structures - Design and Thermal Structural Analysis

DTIC Science & Technology

2007-06-29

than others. It was found that TZ-3Y-E, which is a partially stabilised zirconia powder , was particularly suitable. The percentage of ceramic powder...layered coatings The current ceramic powder that was being used was a fully stabilised zirconia powder TZ-0Y. However a readily available powder...TZ-3Y-E, partially stabilised zirconia powder , was available and utilised. These tests consisted of a combination of 3, 4 and 5 layers. In the

Characterization of Metal Powders Used for Additive Manufacturing

PubMed Central

Slotwinski, JA; Garboczi, EJ; Stutzman, PE; Ferraris, CF; Watson, SS; Peltz, MA

2014-01-01

Additive manufacturing (AM) techniques1 can produce complex, high-value metal parts, with potential applications as critical parts, such as those found in aerospace components. The production of AM parts with consistent and predictable properties requires input materials (e.g., metal powders) with known and repeatable characteristics, which in turn requires standardized measurement methods for powder properties. First, based on our previous work, we assess the applicability of current standardized methods for powder characterization for metal AM powders. Then we present the results of systematic studies carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to structure and chemistry, including X-ray diffraction, energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, and X-Ray photoelectron spectroscopy were also employed. The results of these analyses show how virgin powder changes after being exposed to and recycled from one or more Direct Metal Laser Sintering (DMLS) additive manufacturing build cycles. In addition, these findings can give insight into the actual additive manufacturing process. PMID:26601040

Structural, electrical, optical and magneto-electric characteristics of chemically synthesized CaCu3Ti4O12 dielectric ceramics

NASA Astrophysics Data System (ADS)

Parida, Kalpana; Choudhary, R. N. P.

2017-07-01

CaCu3Ti4O12 (CCTO) was prepared by a chemical reaction method. The pellets prepared from the calcined powder of the material were sintered at 1100 °C. Analysis of x-ray diffraction pattern, recorded on CCTO powder, confirms the phase formation of CCTO. Studies of dielectric (ɛ r, tanδ) and impedance parameters using dielectric and impedance spectroscopy of the compound have provided information about the electrical properties and the dielectric relaxation mechanism of the material. Detailed studies on the variation of electrical conductivity (dc) with temperature show semi-conducting nature of the material. Study of frequency (of applied electric field) dependence of ac conductivity at different temperatures suggests that the compound follows the Jonscher’s power law. Complex impedance spectroscopic analysis suggests that the semicircles formed in the Nyquist plot are connected to the grains, grain boundary and interface effects. An optical energy band gap of ~1.9 eV is obtained from the UV-visible absorbance spectrum. The magnetic data related to magneto-electric (ME) coefficient, measured by varying dc bias magnetic field, have been obtained at room temperature.

Thermokinetic Modeling of Phase Transformation in the Laser Powder Deposition Process

NASA Astrophysics Data System (ADS)

Foroozmehr, Ehsan; Kovacevic, Radovan

2009-08-01

A finite element model coupled with a thermokinetic model is developed to predict the phase transformation of the laser deposition of AISI 4140 on a substrate with the same material. Four different deposition patterns, long-bead, short-bead, spiral-in, and spiral-out, are used to cover a similar area. Using a finite element model, the temperature history of the laser powder deposition (LPD) process is determined. The martensite transformation as well as martensite tempering is considered to calculate the final fraction of martensite, ferrite, cementite, ɛ-carbide, and retained austenite. Comparing the surface hardness topography of different patterns reveals that path planning is a critical parameter in laser surface modification. The predicted results are in a close agreement with the experimental results.

Microscopic evolution of dielectric nanoparticles at different calcination temperatures synthesized via sol-gel auto-combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adil, Muhammad, E-mail: muhammadadil86@hotmail.com; Zaid, Hasnah Mohd, E-mail: hasnamz@petronas.com.my; Chuan, Lee Kean, E-mail: lee.kc@petronas.com.my

2015-07-22

Dielectric nano powder synthesis is carried by a simple and fast sol-gel auto-combustion method. The transformation of crystalline phases of as-synthesized nano powders is investigated through the detailed transmission electron microscopy (TEM), revealed the crystallographic alterations and morphological information even at lattice scale. From specific area electron diffraction (SAED) pattern, has specified the d-spacing and corresponding planes supported by the observed lattice fringes. The morphological characterization of nanoparticles is performed through field-emission scanning electron microscopy (FESEM), exhibiting the increment in particle size due to agglomeration with the increase in annealing temperature. Furthermore, EDX pattern has been used to verify themore » formation of nanoparticles by revealing the presence of required elements.« less

Rapid quantitation of atorvastatin in process pharmaceutical powder sample using Raman spectroscopy and evaluation of parameters related to accuracy of analysis.

PubMed

Lim, Young-Il; Han, Janghee; Woo, Young-Ah; Kim, Jaejin; Kang, Myung Joo

2018-07-05

The purpose of this study was to determine the atorvastatin (ATV) content in process pharmaceutical powder sample using Raman spectroscopy. To establish the analysis method, the influence of the type of Raman measurements (back-scattering or transmission mode), preparation of calibration sample (simple admixing or granulation), sample pre-treatment (pelletization), and spectral pretreatment on the Raman spectra was investigated. The characteristic peak of the active compound was more distinctively detected in transmission Raman mode with a laser spot size of 4mm than in the back-scattering method. Preparation of calibration samples by wet granulation, identical to the actual manufacturing process, provided unchanged spectral patterns for the in process sample, with no changes and/or shifts in the spectrum. Pelletization before Raman analysis remarkably improved spectral reproducibility by decreasing the difference in density between the samples. Probabilistic quotient normalization led to accurate and consistent quantification of the ATV content in the calibration samples (standard error of cross validation: 1.21%). Moreover, the drug content in the granules obtained from five commercial batches were reliably quantified, with no statistical difference (p=0.09) with that obtained by HPLC assay. From these findings, we suggest that transmission Raman analysis may be a fast and non-invasive method for the quantification of ATV in actual manufacturing processes. Copyright © 2018 Elsevier B.V. All rights reserved.

Rapid quantitation of atorvastatin in process pharmaceutical powder sample using Raman spectroscopy and evaluation of parameters related to accuracy of analysis

NASA Astrophysics Data System (ADS)

Lim, Young-Il; Han, Janghee; Woo, Young-Ah; Kim, Jaejin; Kang, Myung Joo

2018-07-01

The purpose of this study was to determine the atorvastatin (ATV) content in process pharmaceutical powder sample using Raman spectroscopy. To establish the analysis method, the influence of the type of Raman measurements (back-scattering or transmission mode), preparation of calibration sample (simple admixing or granulation), sample pre-treatment (pelletization), and spectral pretreatment on the Raman spectra was investigated. The characteristic peak of the active compound was more distinctively detected in transmission Raman mode with a laser spot size of 4 mm than in the back-scattering method. Preparation of calibration samples by wet granulation, identical to the actual manufacturing process, provided unchanged spectral patterns for the in process sample, with no changes and/or shifts in the spectrum. Pelletization before Raman analysis remarkably improved spectral reproducibility by decreasing the difference in density between the samples. Probabilistic quotient normalization led to accurate and consistent quantification of the ATV content in the calibration samples (standard error of cross validation: 1.21%). Moreover, the drug content in the granules obtained from five commercial batches were reliably quantified, with no statistical difference (p = 0.09) with that obtained by HPLC assay. From these findings, we suggest that transmission Raman analysis may be a fast and non-invasive method for the quantification of ATV in actual manufacturing processes.

Patterns of change and continuity in ochre use during the late Middle Stone Age of the Horn of Africa: The Porc-Epic Cave record

PubMed Central

d’Errico, Francesco; Queffelec, Alain

2017-01-01

Ochre is found at numerous Middle Stone Age (MSA) sites and plays a key role in early modern human archaeology. Here we analyse the largest known East African MSA ochre assemblage, comprising 40 kg of ochre, found at Porc-Epic Cave, Ethiopia, spanning a period of at least 4,500 years. Visual characterisation of ochre types, microscopic identification of traces of modification, morphological and morphometric analysis of ochre pieces and modified areas, experimental reproduction of grinding processes, surface texture analysis of archaeological and experimentally ground ochre facets, laser granulometry of ochre powder produced experimentally on different grindstones and by Hamar and Ovahimba women from Ethiopia and Namibia respectively, were, for the first time, combined to explore diachronic shifts in ochre processing technology. Our results identify patterns of continuity in ochre acquisition, treatment and use reflecting both persistent use of the same geological resources and similar uses of iron-rich rocks by late MSA Porc-Epic inhabitants. Considering the large amount of ochre processed at the site, this continuity can be interpreted as the expression of a cohesive cultural adaptation, largely shared by all community members and consistently transmitted through time. A gradual shift in preferred processing techniques and motions is interpreted as reflecting cultural drift within this practice. Evidence for the grinding of ochre to produce small quantities of powder throughout the sequence is consistent with a use in symbolic activities for at least part of the ochre assemblage from Porc-Epic Cave. PMID:28542305

Patterns of change and continuity in ochre use during the late Middle Stone Age of the Horn of Africa: The Porc-Epic Cave record.

PubMed

Rosso, Daniela Eugenia; d'Errico, Francesco; Queffelec, Alain

2017-01-01

Ochre is found at numerous Middle Stone Age (MSA) sites and plays a key role in early modern human archaeology. Here we analyse the largest known East African MSA ochre assemblage, comprising 40 kg of ochre, found at Porc-Epic Cave, Ethiopia, spanning a period of at least 4,500 years. Visual characterisation of ochre types, microscopic identification of traces of modification, morphological and morphometric analysis of ochre pieces and modified areas, experimental reproduction of grinding processes, surface texture analysis of archaeological and experimentally ground ochre facets, laser granulometry of ochre powder produced experimentally on different grindstones and by Hamar and Ovahimba women from Ethiopia and Namibia respectively, were, for the first time, combined to explore diachronic shifts in ochre processing technology. Our results identify patterns of continuity in ochre acquisition, treatment and use reflecting both persistent use of the same geological resources and similar uses of iron-rich rocks by late MSA Porc-Epic inhabitants. Considering the large amount of ochre processed at the site, this continuity can be interpreted as the expression of a cohesive cultural adaptation, largely shared by all community members and consistently transmitted through time. A gradual shift in preferred processing techniques and motions is interpreted as reflecting cultural drift within this practice. Evidence for the grinding of ochre to produce small quantities of powder throughout the sequence is consistent with a use in symbolic activities for at least part of the ochre assemblage from Porc-Epic Cave.

Synthesis, structural and vibrational studies on mixed alkali metal gadolinium double tungstate, K1-xNaxGd(WO4)2

NASA Astrophysics Data System (ADS)

Durairajan, A.; Thangaraju, D.; Moorthy Babu, S.

2013-02-01

Mixed alkali double tungstates K1-xNaxGd(WO4)2 (KNGW) (0 ⩽ x ⩽ 1) were synthesized by solid state reaction using sodium doped monoclinic KGd(WO4)2 (KGW). Synthesized KNGW powders were characterized using powder X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM) and Raman analysis. DTA analysis confirms that the melting point of the KGW matrix increases from 1063 °C to 1255 °C with increasing sodium content. The Powder XRD analyses reveal that mixed phases were observed up to 40 wt.% of Na in the KGW matrix above that percentage there is domination of scheelite structure in the synthesized powder. Polyhedral type, bi-pyramidal shape and spheroid shape morphology was observed for KGW, NKGW and NGW powders respectively. The Raman analysis was carried out to understand the vibrational characteristic changes with mixing of sodium ions in the KGW matrix.

Analysis of ultrasonic effect on powder and application to radioactive sample compaction

NASA Astrophysics Data System (ADS)

Kim, Jungsoon; Sim, Minseop; Kim, Jihyang; Kim, Moojoon

2018-07-01

The effect of ultrasound on powder compaction was analyzed. The decreasing in the friction coefficient of the powder sample is derived theoretically. The compaction rate was improved by the ultrasound. We applied the effect to the compaction of environmental radioactive soil samples. From γ-ray spectroscopy analysis, more radionuclides could be detectable in the sample compacted with ultrasound.

Practical soil analysis by laser induced breakdown spectroscopy employing subtarget supported micro mesh as a powder sample holder

NASA Astrophysics Data System (ADS)

Suyanto, Hery; Lie, Tjung Jie; Kurniawan, Koo Hendrik; Kagawa, Kiichiro; Tjia, May On

2017-11-01

A practical alternative of sample preparation technique is proposed for direct powder analysis using laser-induced breakdown spectroscopy (LIBS) instead of the commonly adopted treatment of pelletizing the powder. The resulted pellet is known to suffer from reduced sensitivity of emission. Besides, it may also give rise to interfering effect from the binder emission. We introduce in this report a more practical technique of using a subtarget supported micro mesh (SSMM) powder sample holder. The LIBS spectrum of standard soil powder measured with 13 mJ 1064 nm Nd:YAG laser in 0.65 kPa ambient air is shown to exhibit the sharp emission lines of all the major elements in the sample. A comparison with the emission spectra measured from the pelletized powder, the spectrum obtained using the SSMM sample holder shows distinctly superior spectral quality marked by the absence of matrix effect found in pelletized powder samples, and the much stronger intensity due to the more effective shock wave plasma induced thermal excitation process produced by the hard subtarget in the sample holder. Repeating the measurement on a number of the standard soil samples of various Pb contents is shown to yield a linear calibration line with practically zero intercept and a detection limit of less than 10 ppm. We have thus demonstrated the viability of the proposed powder sample holder for the development of practical and quantitative powder analysis in the field.

Glove powder's carrying capacity for latex protein: analysis using the ASTM ELISA test.

PubMed

Beezhold, D; Horton, K; Hickey, V; Daddona, J; Kostyal, D

2003-01-01

Glove donning powders carry latex proteins and disperse them into the workplace environment. We have used the ASTM D6499 ELISA to quantify the amount of latex antigen bound to and carried by glove powders. We could differentiate between a small amount of protein actually bound to the powders and a larger amount carried by the powder. Enhanced binding of a major allergen, Hev b 5, to the starch powders was demonstrated by Western blot. The D6499 ELISA is able to measure total latex antigen, soluble and powder bound, simultaneously without the need to centrifuge the samples.

Micro Fluidic Channel Machining on Fused Silica Glass Using Powder Blasting

PubMed Central

Jang, Ho-Su; Cho, Myeong-Woo; Park, Dong-Sam

2008-01-01

In this study, micro fluid channels are machined on fused silica glass via powder blasting, a mechanical etching process, and the machining characteristics of the channels are experimentally evaluated. In the process, material removal is performed by the collision of micro abrasives injected by highly compressed air on to the target surface. This approach can be characterized as an integration of brittle mode machining based on micro crack propagation. Fused silica glass, a high purity synthetic amorphous silicon dioxide, is selected as a workpiece material. It has a very low thermal expansion coefficient and excellent optical qualities and exceptional transmittance over a wide spectral range, especially in the ultraviolet range. The powder blasting process parameters affecting the machined results are injection pressure, abrasive particle size and density, stand-off distance, number of nozzle scanning, and shape/size of the required patterns. In this study, the influence of the number of nozzle scanning, abrasive particle size, and pattern size on the formation of micro channels is investigated. Machined shapes and surface roughness are measured using a 3-dimensional vision profiler and the results are discussed. PMID:27879730

Diamond-silicon carbide composite

DOEpatents

Qian, Jiang; Zhao, Yusheng

2006-06-13

Fully dense, diamond-silicon carbide composites are prepared from ball-milled microcrystalline diamond/amorphous silicon powder mixture. The ball-milled powder is sintered (P=5–8 GPa, T=1400K–2300K) to form composites having high fracture toughness. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPa.dot.m^1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness. X-ray diffraction patterns and Raman spectra indicate that amorphous silicon is partially transformed into nanocrystalline silicon at 5 GPa/873K, and nanocrystalline silicon carbide forms at higher temperatures.

Diamond-Silicon Carbide Composite And Method For Preparation Thereof

DOEpatents

Qian, Jiang; Zhao, Yusheng

2005-09-06

Fully dense, diamond-silicon carbide composites are prepared from ball-milled microcrystalline diamond/amorphous silicon powder mixture. The ball-milled powder is sintered (P=5-8 GPa, T=1400K-2300K) to form composites having high fracture toughness. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPa.multidot.m.sup.1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness. X-ray diffraction patterns and Raman spectra indicate that amorphous silicon is partially transformed into nanocrystalline silicon at 5 GPa/873K, and nanocrystalline silicon carbide forms at higher temperatures.

Crystal structure of methylprednisolone acetate form II, C 24H 32O 6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wheatley, Austin M.; Kaduk, James A.; Gindhart, Amy M.

The crystal structure of methylprednisolone acetate form II, C 24H 32O 6, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Methylprednisolone acetate crystallizes in space groupP2 12 12 1(#19) witha= 8.17608(2),b= 9.67944(3),c= 26.35176(6) Å,V= 2085.474(6) Å 3, andZ= 4. Both hydroxyl groups act as hydrogen bond donors, resulting in a two-dimensional hydrogen bond network in theabplane. C–H…O hydrogen bonds also contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1412.

Packing properties of starch-based powders under mild mechanical stress.

PubMed

Zanardi, I; Gabbrielli, A; Travagli, V

2009-07-01

This study reports the ability to settle of commercial pharmaceutical grade starch samples, both native and pregelatinized. The experiments were carried out under different relative humidity (RH%) conditions and the packing properties were evaluated using both official pharmacopoeial monograph conditions and also modified conditions in order to give a deeper knowledge of tapping under mild mechanical stress. The technique adopted, simulating common pharmaceutical operating practices, appears to be useful to estimate some technologically relevant features of diluent powder materials. Moreover, a general mathematical function has been applied to the experimental data; this could be appropriate for adequately describing material settling patterns and offers practical parameters for characterizing starch powders within the context of a pharmaceutical quality system.

Accuracy in Rietveld quantitative phase analysis: a comparative study of strictly monochromatic Mo and Cu radiations.

PubMed

León-Reina, L; García-Maté, M; Álvarez-Pinazo, G; Santacruz, I; Vallcorba, O; De la Torre, A G; Aranda, M A G

2016-06-01

This study reports 78 Rietveld quantitative phase analyses using Cu  K α 1 , Mo  K α 1 and synchrotron radiations. Synchrotron powder diffraction has been used to validate the most challenging analyses. From the results for three series with increasing contents of an analyte (an inorganic crystalline phase, an organic crystalline phase and a glass), it is inferred that Rietveld analyses from high-energy Mo  K α 1 radiation have slightly better accuracies than those obtained from Cu  K α 1 radiation. This behaviour has been established from the results of the calibration graphics obtained through the spiking method and also from Kullback-Leibler distance statistic studies. This outcome is explained, in spite of the lower diffraction power for Mo radiation when compared to Cu radiation, as arising because of the larger volume tested with Mo and also because higher energy allows one to record patterns with fewer systematic errors. The limit of detection (LoD) and limit of quantification (LoQ) have also been established for the studied series. For similar recording times, the LoDs in Cu patterns, ∼0.2 wt%, are slightly lower than those derived from Mo patterns, ∼0.3 wt%. The LoQ for a well crystallized inorganic phase using laboratory powder diffraction was established to be close to 0.10 wt% in stable fits with good precision. However, the accuracy of these analyses was poor with relative errors near to 100%. Only contents higher than 1.0 wt% yielded analyses with relative errors lower than 20%.

Encapsulation of CO2 into amorphous alpha-cyclodextrin powder at different moisture contents - Part 2: Characterization of complexed powders and determination of crystalline structure.

PubMed

Ho, Thao M; Howes, Tony; Jack, Kevin S; Bhandari, Bhesh R

2016-09-01

This study aims to characterize CO2-α-cyclodextrin (α-CD) inclusion complexes produced from amorphous α-CD powder at moisture contents (MC) close to or higher than the critical level of crystallization (e.g. 13, 15 and 17% MC on wet basis, w.b.) at 0.4 and 1.6MPa pressure for 72h. The results of (13)C NMR, SEM, DSC and X-ray analyses showed that these MC levels were high enough to induce crystallization of CO2-α-CD complexed powders during encapsulation, by which amount of CO2 encapsulated by amorphous α-CD powder was significantly increased. The formation of inclusion complexes were well confirmed by results of FTIR and (13)C NMR analyses through an appearance of a peak associated with CO2 on the FTIR (2334cm(-1)) and NMR (125.3ppm) spectra. Determination of crystal packing patterns of CO2-α-CD complexed powders showed that during crystallization, α-CD molecules were arranged in cage-type structure in which CO2 molecules were entrapped in isolated cavities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

NASA Astrophysics Data System (ADS)

Kara, P.; Csetényi, L. J.; Borosnyói, A.

2016-04-01

In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

MOFabric: Electrospun Nanofiber Mats from PVDF/UiO-66-NH2 for Chemical Protection and Decontamination.

PubMed

Lu, Annie Xi; McEntee, Monica; Browe, Matthew A; Hall, Morgan G; DeCoste, Jared B; Peterson, Gregory W

2017-04-19

Textiles capable of capture and detoxification of toxic chemicals, such as chemical-warfare agents (CWAs), are of high interest. Some metal-organic frameworks (MOFs) exhibit superior reactivity toward CWAs. However, it remains a challenge to integrate powder MOFs into engineered materials like textiles, while retaining functionalities like crystallinity, adsorptivity, and reactivity. Here, we present a simple method of electrospinning UiO-66-NH 2 , a zirconium MOF, with polyvinylidene fluoride (PVDF). The electrospun composite, which we refer to as "MOFabric", exhibits comparable crystal patterns, surface area, chlorine uptake, and simulant hydrolysis to powder UiO-66-NH 2 . The MOFabric is also capable of breaking down GD (O-pinacolyl methylphosphonofluoridae) faster than powder UiO-66-NH 2. Half-life of GD monitored by solid-state NMR for MOFabric is 131 min versus 315 min on powder UiO-66-NH 2 .

Electromagnetic characterization of strontium ferrite powders in series 2000, SU8 polymer

NASA Astrophysics Data System (ADS)

Sholiyi, Olusegun; Williams, John

2014-12-01

In this article, electromagnetic characterization of strontium hexaferrite powders and composites with SU8 was carried out to determine their compatibility with micro and millimeter wave fabrications. The structures of both powders and their composites were scanned with electron microscope to produce the SEM images. Two powder sizes (0.8-1.0 μm and 3-6 μm), were mixed with SU8, spin cast and patterned on wafer, and then characterized using energy dispersive x-ray spectrometry, ferromagnetic resonance (FMR) and vibrating sample magnetometry. In this investigation, FMRs of the samples were determined at 60 GHz while their complex permittivity and permeability were determined using rectangular waveguide method of characterization between 26.5 and 40 GHz frequency range. The results obtained show no adverse effects on the electromagnetic properties of the composites except some slight shift in the resonant frequencies due to anisotropic field of the samples.

Heat transfer model and finite element formulation for simulation of selective laser melting

NASA Astrophysics Data System (ADS)

Roy, Souvik; Juha, Mario; Shephard, Mark S.; Maniatty, Antoinette M.

2017-10-01

A novel approach and finite element formulation for modeling the melting, consolidation, and re-solidification process that occurs in selective laser melting additive manufacturing is presented. Two state variables are introduced to track the phase (melt/solid) and the degree of consolidation (powder/fully dense). The effect of the consolidation on the absorption of the laser energy into the material as it transforms from a porous powder to a dense melt is considered. A Lagrangian finite element formulation, which solves the governing equations on the unconsolidated reference configuration is derived, which naturally considers the effect of the changing geometry as the powder melts without needing to update the simulation domain. The finite element model is implemented into a general-purpose parallel finite element solver. Results are presented comparing to experimental results in the literature for a single laser track with good agreement. Predictions for a spiral laser pattern are also shown.

Atomizing nozzle and process

DOEpatents

Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

1993-07-20

High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

Atomizing nozzle and process

DOEpatents

Anderson, Iver E.; Figliola, Richard S.; Molnar, Holly M.

1992-06-30

High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

New technique for the direct analysis of food powders confined in a small hole using transversely excited atmospheric CO(2) laser-induced gas plasma.

PubMed

Khumaeni, Ali; Ramli, Muliadi; Deguchi, Yoji; Lee, Yong Inn; Idris, Nasrullah; Kurniawan, Koo Hendrik; Lie, Tjung Jie; Kagawa, Kiichiro

2008-12-01

Taking advantage of the differences between the interactions of transversely excited atmospheric (TEA) CO(2) lasers with metal and with organic powder, a new technique for the direct analysis of food powder samples has been developed. In this technique, the powder samples were placed into a small hole with a diameter of 2 mm and a depth of 3 mm and covered by a metal mesh. The TEA CO(2) laser (1500 mJ, 200 ns) was focused on the powder sample surfaces, passing through the metal mesh, at atmospheric pressure in nitrogen gas. It is hypothesized that the small hole functions to confine the powder particles and suppresses the blowing-off of sample, while the metal mesh works as the source of electrons to initiate the strong gas breakdown plasma. The confined powder particles are then ablated by laser irradiation and the ablated particles move into the strong gas breakdown plasma region to be atomized and excited; this method cannot be applied for the case of Nd:YAG lasers because in such case the metal mesh itself was ablated by the laser irradiation. A quantitative analysis of a milk powder sample containing different concentrations of Ca was successfully demonstrated, resulting in a good linear calibration curve with high precision.

The crystal structure of paramagnetic copper(II) oxalate (CuC₂O₄): formation and thermal decomposition of randomly stacked anisotropic nano-sized crystallites.

PubMed

Christensen, Axel Nørlund; Lebech, Bente; Andersen, Niels Hessel; Grivel, Jean-Claude

2014-11-28

Synthetic copper(II) oxalate, CuC2O4, was obtained in a precipitation reaction between a copper(II) solution and an aqueous solution of oxalic acid. The product was identified from its conventional X-ray powder patterns which match that of the copper mineral Moolooite reported to have the composition CuC2O4·0.44H2O. Time resolved in situ investigations of the thermal decomposition of copper(II) oxalate using synchrotron X-ray powder diffraction showed that in air the compound converts to Cu2O at 215 °C and oxidizes to CuO at 345 °C. Thermo gravimetric analysis performed in an inert Ar-gas reveals that the material contains no crystal water and reduces to pure Cu at 295 °C. Magnetic susceptibility measurements in the temperature range from 2 K to 300 K show intriguing paramagnetic behaviour with no sign of magnetic order down to 2 K. A crystal structure investigation is made based on powder diffraction data using one neutron diffraction pattern obtained at 5 K (λ = 1.5949(1) Å) combined with one conventional and two synchrotron X-ray diffraction patterns obtained at ambient temperature using λ = 1.54056, 1.0981 and λ = 0.50483(1) Å, respectively. Based on the X-ray synchrotron data the resulting crystal structure is described in the monoclinic space group P2₁/c (#14) in the P12₁/n1 setting with unit cell parameters a = 5.9598(1) Å, b = 5.6089(1) Å, c = 5.1138 (1) Å, β = 115.320(1)°. The composition is CuC2O4 with atomic coordinates determined by FullProf refinement of the neutron diffraction data. The crystal structure consists of a random stacking of CuC2O4 micro-crystallites where half the Cu-atoms are placed at (2a) and the other half at (2b) positions with the corresponding oxalate molecules centred around the corresponding (2b) and (2a) site positions, respectively. The diffraction patterns obtained for both kinds of radiation show considerable broadening of several Bragg peaks caused by highly anisotropic microstructural size and strain effects. In contrast to the water reported to be present in Moolooite, neither thermogravimetric nor the in situ thermal decomposition investigations and crystal structure analysis of the neutron diffraction data revealed any trace of water. An appendix contains details about the profile parameters for the diffractometers used at the European Synchrotron Radiation Facility and the Institute Max von Laue-Paul Langevin.

To evaluate the effect of various magnesium stearate polymorphs using powder rheology and thermal analysis.

PubMed

Okoye, Patrick; Wu, Stephen H; Dave, Rutesh H

2012-12-01

The effects of magnesium stearate (MgSt) polymorphs-anhydrate (MgSt-A), monohydrate (MgSt-M), and dihydrate (MgSt-D)-on rheological properties of powders were evaluated using techniques such as atomic analysis and powder rheometry. Additional evaluation was conducted using thermal analysis, micromeritics, and tableting forces. In this study, binary ratios of neat MgSt polymorphs were employed as lubricants in powder blends containing acetaminophen (APAP), microcrystalline cellulose (MCC), and lactose monohydrate (LAC-M). Powder rheometry was studied using permeability, basic flow energy (BFE), density, and porosity analysis. Thermal conductivity and differential scanning calorimetric analysis of MgSt polymorphs were employed to elucidate MgSt effect on powder blends. The impact of MgSt polymorphs on compaction characteristics were analyzed via tablet compression forces. Finally, the distribution of atomized magnesium (Mg) ions as a function of intensity was evaluated using laser-induced breakdown spectroscopy (LIBS) on tablets. The results from LIBS analysis indicated the dependency of the MgSt polymorphic forms on the atomized Mg ion intensity, with higher Mg ion intensity suggesting higher lubricity index (i.e. greater propensity to over-lubricate). The results from lubricity index suggested the tendency of blends to over-lubricate based on the MgSt polymorphic forms. Finally, tableting forces suggested that MgSt-D and MgSt-A offered processing benefits such as lower ejection and compression forces, and that MgSt-M showed the most stable compression force in single or combined polymorphic ratios. These results suggested that the initial moisture content, crystal arrangement, intra- and inter-molecular packing of the polymorphs defined their effects on the rheology of lubricated powders.

Size–strain separation in diffraction line profile analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scardi, P.; Ermrich, M.; Fitch, A.

Separation of size and strain effects on diffraction line profiles has been studied in a round robin involving laboratory instruments and synchrotron radiation beamlines operating with different radiation, optics, detectors and experimental configurations. The studied sample, an extensively ball milled iron alloy powder, provides an ideal test case, as domain size broadening and strain broadening are of comparable size. The high energy available at some synchrotron radiation beamlines provides the best conditions for an accurate analysis of the line profiles, as the size–strain separation clearly benefits from a large number of Bragg peaks in the pattern; high counts, reliable intensitymore » values in low-absorption conditions, smooth background and data collection at different temperatures also support the possibility to include diffuse scattering in the analysis, for the most reliable assessment of the line broadening effect. However, results of the round robin show that good quality information on domain size distribution and microstrain can also be obtained using standard laboratory equipment, even when patterns include relatively few Bragg peaks, provided that the data are of good quality in terms of high counts and low and smooth background.« less

Size–strain separation in diffraction line profile analysis

DOE PAGES

Scardi, P.; Ermrich, M.; Fitch, A.; ...

2018-05-29

Separation of size and strain effects on diffraction line profiles has been studied in a round robin involving laboratory instruments and synchrotron radiation beamlines operating with different radiation, optics, detectors and experimental configurations. The studied sample, an extensively ball milled iron alloy powder, provides an ideal test case, as domain size broadening and strain broadening are of comparable size. The high energy available at some synchrotron radiation beamlines provides the best conditions for an accurate analysis of the line profiles, as the size–strain separation clearly benefits from a large number of Bragg peaks in the pattern; high counts, reliable intensitymore » values in low-absorption conditions, smooth background and data collection at different temperatures also support the possibility to include diffuse scattering in the analysis, for the most reliable assessment of the line broadening effect. However, results of the round robin show that good quality information on domain size distribution and microstrain can also be obtained using standard laboratory equipment, even when patterns include relatively few Bragg peaks, provided that the data are of good quality in terms of high counts and low and smooth background.« less

Evaluation of photostability of solid-state nicardipine hydrochloride polymorphs by using Fourier-transformed reflection-absorption infrared spectroscopy - effect of grinding on the photostability of crystal form.

PubMed

Teraoka, Reiko; Otsuka, Makoto; Matsuda, Yoshihisa

2004-11-22

Photostability and physicochemical properties of nicardipine hydrochloride polymorphs (alpha- and beta-form) were studied by using Fourier-transformed reflection-absorption infrared spectroscopy (FT-IR-RAS) of the tablets, X-ray powder diffraction analysis, differential scanning calorimetry (DSC), and color difference measurement. It was clear from the results of FT-IR-RAS spectra after irradiation that nicardipine hydrochloride in the solid state decomposed to its pyridine derivative when exposed to light. The photostability of the ground samples of two forms was also measured in the same manner. The two crystalline forms of the drug changed to nearly amorphous form after 150 min grinding in a mixer mill. X-ray powder diffraction patterns of those ground samples showed almost halo patterns. The nicardipine hydrochloride content on the surface of the tablet was determined based on the absorbance at 1700 cm(-1) attributable to the C=O stretch vibration in FT-IR-RAS spectra before and after irradiation by fluorescent lamp (3500 lx). The photodegradation followed apparently the first-order kinetics for any sample. The apparent photodegradation rate constant of beta-form was greater than that of alpha-form. The ground samples decomposed rapidly under the same light irradiation as compared with the intact crystalline forms. The photodegradation rate constant decreased with increase of the heat of fusion. copyright 2004 Elsevier B.V.

Production of coconut protein powder from coconut wet processing waste and its characterization.

PubMed

Naik, Aduja; Raghavendra, S N; Raghavarao, K S M S

2012-07-01

Virgin coconut oil (VCO) has been gaining popularity in recent times. During its production, byproducts such as coconut skim milk and insoluble protein are obtained which are underutilized or thrown away to the environment at present. This study deals with utilization of these byproducts to obtain a value-added product, namely, coconut protein powder. When coconut milk was subjected to centrifugation, three phases, namely, fat phase (coconut cream), aqueous phase (coconut skim milk), and solid phase (insoluble protein) were obtained. The coconut skim milk and insoluble protein were mixed and homogenized before spray drying to obtain a dehydrated protein powder. The proximate analysis of the powder showed high protein content (33 % w/w) and low fat content (3 % w/w). Protein solubility was studied as a function of pH and ionic content of solvent. Functional properties such as water hydration capacity, fat absorption capacity, emulsifying properties, wettability, and dispersibility of coconut protein powder were evaluated along with morphological characterization, polyphenol content, and color analysis. Coconut protein powder has shown to have good emulsifying properties and hence has potential to find applications in emulsified foods. Sensory analysis showed high overall quality of the product, indicating that coconut protein powder could be a useful food ingredient.

Discrimination of smokeless powders by headspace SPME-GC-MS and SPME-GC-ECD, and the potential implications upon training canine detection of explosives

NASA Astrophysics Data System (ADS)

Harper, Ross J.; Almirall, Jose R.; Furton, Kenneth G.

2005-05-01

This presentation will provide an odour analysis of a variety of smokeless powders & communicate the rapid SPME-GC-ECD method utilized. This paper will also discuss the implications of the headspace analysis of Smokeless Powders upon the choice of training aids for Explosives Detection Canines. Canine detection of explosives relies upon the dogs" ability to equate finding a given explosive odour with a reward, usually in the form of praise or play. The selection of explosives upon which the dogs are trained thus determines which explosives the canines can and potentially cannot find. Commonly, the training is focussed towards high explosives such as TNT and Composition 4, and the low explosives such as Black and Smokeless Powders are added often only for completeness. Powder explosives constitute a major component of explosive incidents throughout the US, and canines trained to detect explosives must be trained across the entire range of powder products. Given the variability in the manufacture and product make-up many smokeless powders do not share common odour chemicals, giving rise to concerns over the extensiveness of canine training. Headspace analysis of a selection of Smokeless Powders by Solid Phase Microextraction Gas Chromatography using Mass Spectrometry (SPME-GC-MS) and Electron Capture Detectors (SPME-GC-ECD) has highlighted significant differences in the chemical composition of the odour available from different brands. This suggests that greater attention should be paid towards the choice of Powder Explosives when assigning canine training aids.

The effect of microwave and conventional heating on a modified sol-gel derived biphasic calcium phosphate

NASA Astrophysics Data System (ADS)

Herradi, S.; Bouhazma, S.; Khaldi, M.; El Hachadi, A.; El Bali, B.; Lachkar, M.

2018-03-01

A facile sol-gel method was used to synthesize either hydroxyapatite (HA) or beta-tricalcium phosphate (β-TCP) as the major phase. Herein, we report, on the one hand, the effect of a very low maturation temperature on the final powder composition after drying step, and on the other hand, we compare the effect of calcination of this powder by microwave or electric furnace. It was found that microwave heating has led to the formation of hydroxyapatite phase upon 180°C for 20 minutes, however, XRD patterns show that the powder becomes less crystallized upon 220°C and amorphous upon 230°C. In contrast, furnace heating at 600°C and 700°C converts the as-synthesized powder to β-TCP as the major phase together with HA as the minor phase. This work shows the possibility to obtain the as-prepared BCP at much lower maturation temperature; it also gives an insight into the role, of either microwave or conventional heating, in controlling the ratio between HA and β-TCP in the sintered powder.

Microstructure and thermoelectric properties of CuInSe2/In2Se3 compound

NASA Astrophysics Data System (ADS)

Wang, Kang; Feng, Jing; Ge, Zhen-Hua; Qin, Peng; Yu, Jie

2018-01-01

CuInSe2 powders were synthesized by solvothermal method, and then the CuInSe2/In2Se3 bulk samples were fabricated by spark plasma sintering (SPS) technique. To investigate the phase composition, the powders were determined by X-ray diffraction (XRD). The microstructures of the powders and bulk samples were observed by scanning electron microscopy (SEM). The transportation of the electronic properties and thermal conductivity were measured at room temperature to 700 K. According to the results, the CuInSe2 powders appeared in flower-like patterns which ranged from 3 μm to 6 μm. CuInSe2 powders were synthesized at 180∘C with a chalcopyrite structure. The Seebeck coefficient increased significantly in composite thermoelectric materials up to 200μVṡK-1 at 623 K. The thermal conductivity of the sample significantly decreases from the room temperature to 700 K. The CuInSe2 bulk composite by solvothermal method achieves the highest ZT value of 0.187 at 700 K.

THERMAL INSULATION SYSTEMS

NASA Technical Reports Server (NTRS)

Augustynowicz, Stanislaw D. (Inventor); Fesmire, James E. (Inventor)

2005-01-01

Thermal insulation systems and with methods of their production. The thermal insulation systems incorporate at least one reflection layer and at least one spacer layer in an alternating pattern. Each spacer layer includes a fill layer and a carrier layer. The fill layer may be separate from the carrier layer, or it may be a part of the carrier layer, i.e., mechanically injected into the carrier layer or chemically formed in the carrier layer. Fill layers contain a powder having a high surface area and low bulk density. Movement of powder within a fill layer is restricted by electrostatic effects with the reflection layer combined with the presence of a carrier layer, or by containing the powder in the carrier layer. The powder in the spacer layer may be compressed from its bulk density. The thermal insulation systems may further contain an outer casing. Thermal insulation systems may further include strips and seams to form a matrix of sections. Such sections serve to limit loss of powder from a fill layer to a single section and reduce heat losses along the reflection layer.

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

PubMed

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

2010-08-01

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

Materials Research for Advanced Inertial Instrumentation; Task 3: Rare Earth Magnetic Material Technology as Related to Gyro Torquers and Motors.

DTIC Science & Technology

1981-12-01

POWDER FEED S PRAY STREAM POWER INPUT - COOLING GAS I WATER DEPOSIT SUBSTRATEI 10/77 12404 REV A 1/78 Figure 13. Schematic sketch of spray process .( 14...as-HIPed condition ...... 26 13 Schematic sketch of spray process ........... ........ 3 14 X-ray diffraction patterns on deposits formed from (A) 42.0...Br values to be low. When the alloy powder is magnetically aligned and cold isostatically compacted followed by densificaton by lIPing, there is

Application of Powder Diffraction Methods to the Analysis of the Atomic Structure of Nanocrystals: The Concept of the Apparent Lattice Parameter (ALP)

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Gierlotka, S.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H.-P.; Palosz, W.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The applicability of standard methods of elaboration of powder diffraction data for determination of the structure of nano-size crystallites is analysed. Based on our theoretical calculations of powder diffraction data we show, that the assumption of the infinite crystal lattice for nanocrystals smaller than 20 nm in size is not justified. Application of conventional tools developed for elaboration of powder diffraction data, like the Rietveld method, may lead to erroneous interpretation of the experimental results. An alternate evaluation of diffraction data of nanoparticles, based on the so-called 'apparent lattice parameter' (alp) is introduced. We assume a model of nanocrystal having a grain core with well-defined crystal structure, surrounded by a surface shell with the atomic structure similar to that of the core but being under a strain (compressive or tensile). The two structural components, the core and the shell, form essentially a composite crystal with interfering, inseparable diffraction properties. Because the structure of such a nanocrystal is not uniform, it defies the basic definitions of an unambiguous crystallographic phase. Consequently, a set of lattice parameters used for characterization of simple crystal phases is insufficient for a proper description of the complex structure of nanocrystals. We developed a method of evaluation of powder diffraction data of nanocrystals, which refers to a core-shell model and is based on the 'apparent lattice parameter' methodology. For a given diffraction pattem, the alp values are calculated for every individual Bragg reflection. For nanocrystals the alp values depend on the diffraction vector Q. By modeling different a0tomic structures of nanocrystals and calculating theoretically corresponding diffraction patterns using the Debye functions we showed, that alp-Q plots show characteristic shapes which can be used for evaluation of the atomic structure of the core-shell system. We show, that using a simple model of a nanocrystal with spherical shape and centro-symmetric strain at the surface shell we obtain theoretical alp-Q values which match very well the alp-Q plots determined experimentally for Sic, GaN, and diamond nanopowders. The theoretical models are defined by the lattice parameter of the grain core, thickness of the surface shell, and the magnitude and distribution of the strain field in the surface shell. According to our calculations, the part of the diffraction pattern measured at relatively low diffraction vectors Q (below 10/angstrom) provides information on the surface strain, whle determination of the lattice parameters in the grain core requires measurements at large Q-values (above 15 - 20/angstrom).

Dietary Cocoa Powder Improves Hyperlipidemia and Reduces Atherosclerosis in apoE Deficient Mice through the Inhibition of Hepatic Endoplasmic Reticulum Stress.

PubMed

Guan, Hua; Lin, Yan; Bai, Liang; An, Yingfeng; Shang, Jianan; Wang, Zhao; Zhao, Sihai; Fan, Jianglin; Liu, Enqi

2016-01-01

Cocoa powder is rich in flavonoids, which have many beneficial effects on human health, including antioxidative and anti-inflammatory effects. The aim of our study was to investigate whether the intake of cocoa powder has any influence on hyperlipidemia and atherosclerosis and examine the underlying molecular mechanisms. We fed apoE knockout mice a Western diet supplemented with either 0.2% (low group) or 2% (high group) cocoa powder for 12 weeks. The groups fed dietary cocoa powder showed a significant reduction in both plasma cholesterol levels and aortic atherosclerosis compared to the control group. Analysis of mRNA profiling of aortic atherosclerotic lesions revealed that the expression of several genes related to apoptosis, lipid metabolism, and inflammation was significantly reduced, while the antiapoptotic gene Bcl2 was significantly increased in the cocoa powder group compared to the control. RT-PCR analysis along with Western blotting revealed that a diet containing cocoa powder inhibited the expression of hepatic endoplasmic reticulum stress. These data suggest that cocoa powder intake improves hyperlipidemia and atherosclerosis, and such beneficial effects are possibly mediated through the suppression of hepatic endoplasmic reticulum stress.

PVA/NaCl/MgO nanocomposites-microstructural analysis by whole pattern fitting method

NASA Astrophysics Data System (ADS)

Prashanth, K. S.; Mahesh, S. S.; Prakash, M. B. Nanda; Somashekar, R.; Nagabhushana, B. M.

2018-04-01

The nanofillers in the macromolecular matrix have displayed noteworthy changes in the structure and reactivity of the polymer nanocomposites. Novel functional materials usually consist of defects and are largely disordered. The intriguing properties of these materials are often attributed to defects. X-ray line profiles from powder diffraction reveal the quantitative information about size distribution and shape of diffracting domains which governs the contribution from small conventional X-ray diffraction (XRD) techniques to enumerate the microstructural information. In this study the MgO nanoparticles were prepared by solution combustion method and PVA/NaCl/MgO nanocomposite films were synthesized by the solvent cast method. Microstructural parameters viz crystal defects like stacking faults and twin faults, compositional inhomogeneity, crystallite size and lattice strain (g in %), were extracted using whole pattern fitting method.

Crystal structure of choline fenofibrate (Trilipix®), (C5H14NO) (C17H14ClO4)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James A.; Zhong, Kai; Gindhart, Amy M.

2016-04-04

The crystal structure of choline fenofibrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Choline fenofibrate crystallizes in space groupPbca(#61) witha= 12.341 03(2),b= 28.568 70(6),c= 12.025 62(2) Å,V= 4239.84(1) Å 3, andZ= 8. The hydroxyl group of the choline anion makes a strong hydrogen bond to the ionized carboxylate group of the fenofibrate anion. Together with C–H···O hydrogen bonds, these link the cations and anions into layers parallel to theac-plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

Screenable contact structure and method for semiconductor devices

DOEpatents

Ross, Bernd

1980-08-26

An ink composition for deposition upon the surface of a semiconductor device to provide a contact area for connection to external circuitry is disclosed, the composition comprising an ink system containing a metal powder, a binder and vehicle, and a metal frit. The ink is screened onto the semiconductor surface in the desired pattern and is heated to a temperature sufficient to cause the metal frit to become liquid. The metal frit dissolves some of the metal powder and densifies the structure by transporting the dissolved metal powder in a liquid sintering process. The sintering process typically may be carried out in any type of atmosphere. A small amount of dopant or semiconductor material may be added to the ink systems to achieve particular results if desired.

Patterns of megafloral change across the Cretaceous-Tertiary boundary in the Northern Great Plains and Rocky Mountains

NASA Technical Reports Server (NTRS)

Johnson, Kirk R.; Hickey, Leo J.

1988-01-01

The spatial and temporal distribution of vegetation in the terminal Cretaceous of Western Interior North America was a complex mosaic resulting from the interaction of factors including a shifting coastline, tectonic activity, a mild, possibly deteriorating climate, dinosaur herbivory, local facies effects, and a hypothesized bolide impact. In order to achieve sufficient resolution to analyze this vegetational pattern, over 100 megafloral collecting sites were established, yielding approximately 15,000 specimens, in Upper Cretaceous and lower Paleocene strata in the Williston, Powder River, and Bighorn basins in North Dakota, Montana, and Wyoming. These localities were integrated into a lithostratigraphic framework that is based on detailed local reference sections and constrained by vertebrate and palynomorph biostratigraphy, magnetostratigraphy, and sedimentary facies analysis. A regional biostratigraphy based on well located and identified plant megafossils that can be used to address patterns of floral evolution, ecology, and extinction is the goal of this research. Results of the analyses are discussed.

Cheetah: software for high-throughput reduction and analysis of serial femtosecond X-ray diffraction data

PubMed Central

Barty, Anton; Kirian, Richard A.; Maia, Filipe R. N. C.; Hantke, Max; Yoon, Chun Hong; White, Thomas A.; Chapman, Henry

2014-01-01

The emerging technique of serial X-ray diffraction, in which diffraction data are collected from samples flowing across a pulsed X-ray source at repetition rates of 100 Hz or higher, has necessitated the development of new software in order to handle the large data volumes produced. Sorting of data according to different criteria and rapid filtering of events to retain only diffraction patterns of interest results in significant reductions in data volume, thereby simplifying subsequent data analysis and management tasks. Meanwhile the generation of reduced data in the form of virtual powder patterns, radial stacks, histograms and other meta data creates data set summaries for analysis and overall experiment evaluation. Rapid data reduction early in the analysis pipeline is proving to be an essential first step in serial imaging experiments, prompting the authors to make the tool described in this article available to the general community. Originally developed for experiments at X-ray free-electron lasers, the software is based on a modular facility-independent library to promote portability between different experiments and is available under version 3 or later of the GNU General Public License. PMID:24904246

Buckskin Drill Hole and CheMin X-ray Diffraction

NASA Image and Video Library

2015-12-17

The graph at right presents information from the NASA Curiosity Mars rover's onboard analysis of rock powder drilled from the "Buckskin" target location, shown at left. X-ray diffraction analysis of the Buckskin sample inside the rover's Chemistry and Mineralogy (CheMin) instrument revealed the presence of a silica-containing mineral named tridymite. This is the first detection of tridymite on Mars. Peaks in the X-ray diffraction pattern are from minerals in the sample, and every mineral has a diagnostic set of peaks that allows identification. The image of Buckskin at left was taken by the rover's Mars Hand Lens Imager (MAHLI) camera on July 30, 2015, and is also available at PIA19804. http://photojournal.jpl.nasa.gov/catalog/PIA20271

Synthesis and characterization of β-Ni(OH)2 embedded with MgO and ZnO nanoparticles as nanohybrids for energy storage devices

NASA Astrophysics Data System (ADS)

Kumar, C. R. Ravi; Santosh, M. S.; Nagaswarupa, H. P.; Prashantha, S. C.; Yallappa, S.; Kumar, M. R. Anil

2017-06-01

In this study, the electrode material (nickel hydroxide powder) has been synthesized by a co-precipitation method using sodium hydroxide and nickel sulphate as precipitator and nickel source, respectively. The obtained nickel hydroxide powder has been subsequently embedded with biosynthesized MgO and ZnO nanoparticles as nanohybrids, which have been investigated as a novel hybrid electrode material for power-storage applications. The powder x-ray diffraction pattern of nickel hydroxide (Ni(OH)2)-based nanohybrid materials reveals a typical β-phase. Fourier transform infrared spectroscopy confirms the embedded structures of nanohybrids and thermal stability by thermogravimetry and differential thermal) analysis. The electrochemical properties of these materials have been studied using cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The specific capacitance values are found to be 439, 1076, and 622 F g-1 for bare β-Ni(OH)2, and for β-Ni(OH)2 embedded with ZnO and MgO nanohybrids, respectively, at a scan rate of 10 mVs-1. The enhanced capacitance of nanohybrids is also evident from EIS measurements. Galvanostatic charge-discharge tests for these designed nanohybrids show excellent capacitance performance in battery and supercapacitor applications. These innovative results could be considered for the expansion of novel resources to scale for power-storage applications and may contribute to the development of this niche area at large.

A method for enhancing gunshot residue patterns on dark and multicolored fabrics compared with the modified Griess test.

PubMed

Bailey, James A; Casanova, Ruby S; Bufkin, Kim

2006-07-01

In using infrared or infrared-enhanced photography to examine gunshot residue (GSR) on dark-colored clothing, the GSR particles are microscopically examined directly on the fabric followed by the modified Griess test (MGT) for nitrites. In conducting the MGT, the GSR is transferred to treated photographic paper for visualization. A positive reaction yields an orange color on specially treated photographic paper. The examiner also evaluates the size of the powder pattern based on the distribution of nitrite reaction sites or density. A false-positive reaction can occur using the MGT due to contaminants or dyes that produce an orange cloud reaction as well. A method for enhancing visualization of the pattern produced by burned and partially unburned powder is by treatment of the fabric with a solution of sodium hypochlorite. In order to evaluate the results of sodium hypochlorite treatment for GSR visualization, the MGT was used as a reference pattern. Enhancing GSR patterns on dark or multicolored clothing was performed by treating the fabric with an application of 5.25% solution of sodium hypochlorite. Bleaching the dyes in the fabric enhances visualization of the GSR pattern by eliminating the background color. Some dyes are not affected by sodium hypochlorite; therefore, bleaching may not enhance the GSR patterns in some fabrics. Sodium hypochlorite provides the investigator with a method for enhancing GSR patterns directly on the fabric. However, this study is not intended to act as a substitute for the MGT or Sodium Rhodizonate test.

Analysis of the mechanical behavior of a titanium scaffold with a repeating unit-cell substructure.

PubMed

Ryan, Garrett; McGarry, Patrick; Pandit, Abhay; Apatsidis, Dimitrios

2009-08-01

Titanium scaffolds with controlled microarchitecture have been developed for load bearing orthopedic applications. The controlled microarchitecture refers to a repeating array of unit-cells, composed of sintered titanium powder, which make up the scaffold structure. The objective of this current research was to characterize the mechanical performance of three scaffolds with increasing porosity, using finite element analysis (FEA) and to compare the results with experimental data. Scaffolds were scanned using microcomputed tomography and FEA models were generated from the resulting computer models. Macroscale and unit-cell models of the scaffolds were created. The material properties of the sintered titanium powders were first evaluated in mechanical tests and the data used in the FEA. The macroscale and unit-cell FEA models proved to be a good predictor of Young's modulus and yield strength. Although macroscale models showed similar failure patterns and an expected trend in UCS, strain at UCS did not compare well with experimental data. Since a rapid prototyping method was used to create the scaffolds, the original CAD geometries of the scaffold were also evaluated using FEA but they did not reflect the mechanical properties of the physical scaffolds. This indicates that at present, determining the actual geometry of the scaffold through computed tomography imaging is important. Finally, a fatigue analysis was performed on the scaffold to simulate the loading conditions it would experience as a spinal interbody fusion device.

User Guide to RockJock - A Program for Determining Quantitative Mineralogy from X-Ray Diffraction Data

USGS Publications Warehouse

Eberl, D.D.

2003-01-01

RockJock is a computer program that determines quantitative mineralogy in powdered samples by comparing the integrated X-ray diffraction (XRD) intensities of individual minerals in complex mixtures to the intensities of an internal standard. Analysis without an internal standard (standardless analysis) also is an option. This manual discusses how to prepare and X-ray samples and mineral standards for these types of analyses and describes the operation of the program. Carefully weighed samples containing an internal standard (zincite) are ground in a McCrone mill. Randomly oriented preparations then are X-rayed, and the X-ray data are entered into the RockJock program. Minerals likely to be present in the sample are chosen from a list of standards, and the calculation is begun. The program then automatically fits the sum of stored XRD patterns of pure standard minerals (the calculated pattern) to the measured pattern by varying the fraction of each mineral standard pattern, using the Solver function in Microsoft Excel to minimize a degree of fit parameter between the calculated and measured pattern. The calculation analyzes the pattern (usually 20 to 65 degrees two-theta) to find integrated intensities for the minerals. Integrated intensities for each mineral then are determined from the proportion of each mineral standard pattern required to give the best fit. These integrated intensities then are compared to the integrated intensity of the internal standard, and the weight percentages of the minerals are calculated. The results are presented as a list of minerals with their corresponding weight percent. To some extent, the quality of the analysis can be checked because each mineral is analyzed independently, and, therefore, the sum of the analysis should approach 100 percent. Also, the method has been shown to give good results with artificial mixtures. The program is easy to use, but does require an understanding of mineralogy, of X-ray diffraction practice, and an elementary knowledge of the Excel program.

Study of AC Magnetic Properties and Core Losses of Fe/Fe3O4-epoxy Resin Soft Magnetic Composite

NASA Astrophysics Data System (ADS)

Laxminarayana, T. A.; Manna, Subhendu Kumar; Fernandes, B. G.; Venkataramani, N.

Soft Magnetic Composites (SMC) were prepared by coating of nanocrystalline Fe3O4 particles, synthesized by co-precipitation method, on atomized iron powder of particle size less than 53 μm in size using epoxy resin as a binder between iron and Fe3O4. Fe3O4 was chosen, for its high electric resistivity and suitable magnetic properties, to keep the coating layer magnetic and seek improvement to the magnetic properties of SMC. SEM images and XRD patterns were recorded in order to investigate the coatings on the surface of iron powder. A toroid was prepared by cold compaction of coated iron powder at 1050 MPa and subsequently cured at 150˚C for 1 hr in argon atmosphere. For comparison of properties, a toroid of uncoated iron powder was also compacted at 1050 MPa and annealed at 600˚C for 2 hr in argon atmosphere. The coated iron powder composite has a resistivity of greater than 200 μΩm, measured by four probe method. A comparison of Magnetic Hysteresis loops and core losses using B-H Loop tracer in the frequency range 0 to 1500 Hz on the coated and uncoated iron powder is reported.

Use of a continual sweep motion to compare air polishing devices, powders and exposure time on unexposed root cementum.

PubMed

Herr, Mandy L; DeLong, Ralph; Li, Yuping; Lunos, Scott A; Stoltenberg, Jill L

2017-07-01

Low abrasive air polishing powders are a viable method for subgingival biofilm removal. This in vitro study evaluated the effects of air polishing using a standard tip on cementum following clinically recommended protocols. Forty-eight teeth were randomly divided into eight groups with six teeth per group. Teeth were treated using either a Hu-Friedy EMS or DENTSPLY Cavitron ® air polishing device. One of three glycine powders (Air-flow 25 µm, Clinpro 45 μm, Clinpro+TCP 45 μm) or a sodium bicarbonate powder (NaHCO 3  85 μm) was sprayed on cementum using a clinically relevant sweeping motion. Volume and depth of cementum removed after 5 and 90 s exposures were calculated. Surface texture was evaluated using SEMs taken following the last exposure. After 5 s exposures, neither unit nor powder had a substantial effect on volume loss or defect depth. After 90 s exposures, differences between powders existed only for the DENTSPLY unit (p < 0.0001). Pairwise comparisons for this unit revealed mean volume loss and maximum defect depth were greater for NaHCO 3 85 μm than the glycine powders (p < 0.0001). The 90 s exposure produced greater mean volume loss and defect depth for all powders (p < 0.0001). SEM images revealed dentinal tubule exposure with all powders; however, exposed tubules were larger and more prevalent for NaHCO 3 85 μm. Root surface loss was similar for glycine powders evaluated in this study. Differences in powder performance between units may be related to tip apertures and spray patterns. Additional research is needed to determine if cementum loss is greater than what occurs with conventional biofilm removal methods, such as curets and ultrasonic scalers.

Rapid identification of pearl powder from Hyriopsis cumingii by Tri-step infrared spectroscopy combined with computer vision technology

NASA Astrophysics Data System (ADS)

Liu, Siqi; Wei, Wei; Bai, Zhiyi; Wang, Xichang; Li, Xiaohong; Wang, Chuanxian; Liu, Xia; Liu, Yuan; Xu, Changhua

2018-01-01

Pearl powder, an important raw material in cosmetics and Chinese patent medicines, is commonly uneven in quality and frequently adulterated with low-cost shell powder in the market. The aim of this study is to establish an adequate approach based on Tri-step infrared spectroscopy with enhancing resolution combined with chemometrics for qualitative identification of pearl powder originated from three different quality grades of pearls and quantitative prediction of the proportions of shell powder adulterated in pearl powder. Additionally, computer vision technology (E-eyes) can investigate the color difference among different pearl powders and make it traceable to the pearl quality trait-visual color categories. Though the different grades of pearl powder or adulterated pearl powder have almost identical IR spectra, SD-IR peak intensity at about 861 cm- 1 (v2 band) exhibited regular enhancement with the increasing quality grade of pearls, while the 1082 cm- 1 (v1 band), 712 cm- 1 and 699 cm- 1 (v4 band) were just the reverse. Contrastly, only the peak intensity at 862 cm- 1 was enhanced regularly with the increasing concentration of shell powder. Thus, the bands in the ranges of (1550-1350 cm- 1, 730-680 cm- 1) and (830-880 cm- 1, 690-725 cm- 1) could be exclusive ranges to discriminate three distinct pearl powders and identify adulteration, respectively. For massive sample analysis, a qualitative classification model and a quantitative prediction model based on IR spectra was established successfully by principal component analysis (PCA) and partial least squares (PLS), respectively. The developed method demonstrated great potential for pearl powder quality control and authenticity identification in a direct, holistic manner.

Rapid identification of pearl powder from Hyriopsis cumingii by Tri-step infrared spectroscopy combined with computer vision technology.

PubMed

Liu, Siqi; Wei, Wei; Bai, Zhiyi; Wang, Xichang; Li, Xiaohong; Wang, Chuanxian; Liu, Xia; Liu, Yuan; Xu, Changhua

2018-01-15

Pearl powder, an important raw material in cosmetics and Chinese patent medicines, is commonly uneven in quality and frequently adulterated with low-cost shell powder in the market. The aim of this study is to establish an adequate approach based on Tri-step infrared spectroscopy with enhancing resolution combined with chemometrics for qualitative identification of pearl powder originated from three different quality grades of pearls and quantitative prediction of the proportions of shell powder adulterated in pearl powder. Additionally, computer vision technology (E-eyes) can investigate the color difference among different pearl powders and make it traceable to the pearl quality trait-visual color categories. Though the different grades of pearl powder or adulterated pearl powder have almost identical IR spectra, SD-IR peak intensity at about 861cm -1 (v 2 band) exhibited regular enhancement with the increasing quality grade of pearls, while the 1082cm -1 (v 1 band), 712cm -1 and 699cm -1 (v 4 band) were just the reverse. Contrastly, only the peak intensity at 862cm -1 was enhanced regularly with the increasing concentration of shell powder. Thus, the bands in the ranges of (1550-1350cm -1 , 730-680cm -1 ) and (830-880cm -1 , 690-725cm -1 ) could be exclusive ranges to discriminate three distinct pearl powders and identify adulteration, respectively. For massive sample analysis, a qualitative classification model and a quantitative prediction model based on IR spectra was established successfully by principal component analysis (PCA) and partial least squares (PLS), respectively. The developed method demonstrated great potential for pearl powder quality control and authenticity identification in a direct, holistic manner. Copyright © 2017. Published by Elsevier B.V.

An analysis of un-dissolved powders of instant powdered soup by using ultrasonographic image

NASA Astrophysics Data System (ADS)

Kawaai, Yukinori; Kato, Kunihito; Yamamoto, Kazuhiko; Kasamatsu, Chinatsu

2008-11-01

Nowadays, there are many instant powdered soups around us. When we make instant powdered soup, sometimes we cannot dissolve powders perfectly. Food manufacturers want to improve this problem in order to make better products. Therefore, they have to measure the state and volume of un-dissolved powders. Earlier methods for analyzing removed the un-dissolved powders from the container, the state of the un-dissolved power was changed. Our research using ultrasonographic image can measure the state of un-dissolved powders with no change by taking cross sections of the soup. We then make 3D soup model from these cross sections of soup. Therefore we can observe the inside of soup that we do not have ever seen. We construct accurate 3D model. We can visualize the state and volume of un-dissolved powders with analyzing the 3D soup models.

Stability of a Cu0.7Co2.3O4 electrode during the oxygen evolution reaction for alkaline anion-exchange membrane water electrolysis

NASA Astrophysics Data System (ADS)

Kang, Kyoung Eun; Kim, Chi Ho; Lee, Myung Sup; Jung, Chang Wook; Kim, Yang Do; Lee, Jae Ho

2018-01-01

The electrode materials for oxygen evolution, especially non-platinum group metal oxides, have attracted increasing attention. Among the spinel-type transition metal oxides, Cu0.7Co2.3O4 powders were evaluated as a potential replacement for expensive dimensionally stabilized anode materials. Cu0.7Co2.3O4 powder for use as an electrode material for oxygen evolution in an alkaline anion-exchange membrane water electrolyzer was prepared using a thermal decomposition method. The Cu0.7Co2.3O4 powders heat-treated at 250 °C exhibited the same X-ray diffraction patterns without any secondary phases as the Co3O4 spinel structure did. The Cu0.7Co2.3O4 powders heat-treated at 250 °C for 30 minutes showed the smallest mean particle size of approximately 376 nm with the powders having a homogeneous shape and size distribution. The fine powders with a relatively homogeneous size distribution showed a higher current density during the oxygen evolution reaction. The lifetime of the Cu0.7Co2.3O4 electrode was relatively long at a low current density, but was quickly shortened due to physical detachment of the Cu0.7Co2.3O4 powders as the current density was increased. This study showed that the efficiency and the stability of Cu0.7Co2.3O4 powders during the oxygen evolution reaction were related directly to the active electrode area.

Work-related allergy and asthma in spice mill workers - The impact of processing dried spices on IgE reactivity patterns.

PubMed

van der Walt, Anita; Lopata, Andreas L; Nieuwenhuizen, Natalie E; Jeebhay, Mohamed F

2010-01-01

Three spice mill workers developed work-related allergy and asthma after prolonged exposure to high levels (>10 mg/m(3)) of inhalable spice dust. Patterns of sensitization to a variety of spices and putative allergens were identified. Work-related allergy and asthma were assessed on history, clinical evaluation, pulmonary function and fractional exhaled nitric oxide. Specific IgE reactivity to a range of common inhalant, food and spice allergens was evaluated using ImmunoCAP and allergen microarray. The presence of non-IgE-mediated reactions was determined by basophil stimulation (CAST-ELISA). Specific allergens were identified by immunoblotting to extracts of raw and dried processed garlic, onion and chili pepper. Asthma was confirmed in all 3 subjects, with work-related patterns prominent in worker 1 and 3. Sensitization to multiple spices and pollen was observed in both atopic workers 1 and 2, whereas garlic and chili pepper sensitization featured in all 3 workers. Microarray analysis demonstrated prominent profilin reactivity in atopic worker 2. Immunoblotting demonstrated a 50-kDa cross-reactive allergen in garlic and onion, and allergens of approximately 40 and 52 kDa in chili pepper. Dry powdered garlic and onion demonstrated greater IgE binding. This study demonstrated IgE reactivity to multiple spice allergens in workers exposed to high levels of inhalable spice dust. Processed garlic and onion powder demonstrated stronger IgE reactivity than the raw plant. Atopy and polysensitization to various plant profilins, suggesting pollen-food syndrome, represent additional risk factors for sensitizer-induced work-related asthma in spice mill workers. 2010 S. Karger AG, Basel.

Synthesis of nanostructured vanadium powder by high-energy ball milling: X-ray diffraction and high-resolution electron microscopy characterization

NASA Astrophysics Data System (ADS)

Krishnan, Vinoadh Kumar; Sinnaeruvadi, Kumaran

2016-10-01

Vanadium metal powders, ball milled with different surfactants viz., stearic acid, KCl and NaCl, have been studied by X-ray diffraction and transmission electron microscopy. The surfactants alter the microstructural and morphological characteristics of the powders. Ball milling with stearic acid results in solid-state amorphization, while powders milled with KCl yield vanadium-tungsten carbide nanocomposite mixtures. NaCl proved to be an excellent surfactant for obtaining nanostructured fusion-grade vanadium powders. In order to understand the reaction mechanism behind any interstitial addition in the ball-milled powders, CHNOS analysis was performed.

Characterization of the Waukesha Illite: A mixed-polytype illite in the Clay Mineral Society repository

USGS Publications Warehouse

Grathoff, Georg H.; Moore, D.M.

2002-01-01

The Waukesha Illite is an excellent example of the illites found in argillaceous rocks, typical for Paleozoic shales that have undergone significant burial diagenesis during their geologic history. It consists of a mixture of detrital 2M1, interpreted to be a residuum of karstification within Silurian carbonates, and diagenetic 1M and 1Md illite. The chemistry and the age of the illite polytypes are different. Extrapolating to 100%, the 1M and 1Md polytypes have an apparent diagenetic age between 295 and 325 Ma. The chemistry of the 1M polytype could not be determined because of its low abundance. The approximate chemical composition of the 1Md polytype is 0.67 K, 3.6 Si, and 1.9 Al per half unit cell. The 2M1 polytype has an apparent detrital age between 440 and 520 Ma, and an approximate chemical composition per half unit cell of 0.78 K, 3.4 Si, and 2.1 Al, all within our margin of error. X-ray diffraction (XRD) results of both random powder and oriented preparations both indicate that the Waukesha Illite consists of a mixture of illites. The XRD patterns of the random powder preparation indicate it is a physical mixture of three different illite polytypes. This result was confirmed using 3 different methods: (1) by measuring illite polytype-specific reflections; (2) by mixing illite polytype reference samples; and (3) by mixing WILDFIRE calculated XRD patterns. Decomposition of the illite 001 XRD peak from oriented preparations also indicates mixtures of illites. However, the proportions of the three illitic components derived from the oriented 001 peak decomposition differ from those results derived from the analysis of the random powder data. Therefore, the shape of the 001 reflection of the Waukesha Illite cannot be explained by mixing the three different illite polytypes.

Influence of crystallite size on the magnetic and heat generation properties of La0.77Sr0.23MnO3 nanoparticles for hyperthermia applications

NASA Astrophysics Data System (ADS)

Das, Harinarayan; Inukai, Akihiro; Debnath, Nipa; Kawaguchi, Takahiko; Sakamoto, Naonori; Hoque, Sheikh Manjura; Aono, Hiromichi; Shinozaki, Kazuo; Suzuki, Hisao; Wakiya, Naoki

2018-01-01

In this paper, we report a detailed study of magnetic properties and AC magnetic heat generation characteristics of La0.77Sr0.23MnO3 (LSMO) nanoparticles to investigate appropriate crystallite size with a view to the proper application of self-controlled magnetic hyperthermia treatments of cancer. A series of nanocrystalline LSMO manganite was synthesized through the chemical route called as "polymerized complex method" and then subsequently annealed at the different temperature from 600 to 1400 °C to obtain various crystallite size. Phase formation and crystal structure of the prepared powder were determined by the powder X-ray diffraction (XRD) using Rietveld analysis. The XRD patterns reveal that all powder samples are a single phase rhombohedral perovskite-like structure with R 3 bar c space group. The mean crystallite size of prepared particles varied from 19 to 243.8 nm with the increase of the annealing temperature starting from 600 to 1400 °C. The field emission scanning electron microscopy (FE-SEM) analysis shows the surface morphology with a strong agglomeration of fine nanoparticles. The Magnetic study reveals that these nanoparticles exhibit ferromagnetic nature with different value of magnetization, coercivity, Curie temperature which is strongly dependent on their crystallite size. The maximum saturation temperature (TS = 66 °C) under AC magnetic field (H = 1.77 kA/m, f = 370 kHz) was found for the crystallite size of 39.5 nm due to its pure single domain phase. Such LSMO nanoparticles, having the higher heating rate, can be used in magnetically induced hyperthermia cancer treatment.

Monitoring trends in recreational drug use from the analysis of the contents of amnesty bins in gay dance clubs.

PubMed

Yamamoto, T; Kawsar, A; Ramsey, J; Dargan, P I; Wood, D M

2013-12-01

In 2011/12, 8.9% of the UK population reported use of recreational drugs. Problems related to drug use is a major financial burden to society and a common reason for attendance to hospital. The aim of this study was to establish current trends in recreational drug use amongst individuals attending gay-friendly nightclubs in South London. Contents of drug amnesty bins located at two night clubs were documented and categorized into powders, herbal products, liquids, tablets and capsules. These were then sent to a Home Office licensed laboratory for identification through a pre-existing database of almost 25 000 substances. If required, further qualitative analysis was performed. A total of 544 samples were obtained. Of them, 240 (44.1%) were liquids, 220 (40.4%) powders, 42 (7.7%) herbal and 41 (7.5%) tablets or capsules. Gamma-butyrolactone (GBL) was the most common liquid drug (n = 160, 66.7%) followed by poppers (n = 72, 30.0%). Powders provided the widest range of drugs with mephedrone being the most common (n = 105, 47.7%) followed by ketamine (n = 28, 12.7%), 3,4-methylenedioxy-N-methylamphetamine (MDMA) (n = 26, 11.8%), and cocaine (n = 21, 9.5%). Tablets and capsules included medicinal drugs, recreational drugs and plaster of Paris tablets that mimicked the appearance of 'ecstasy' tablets. This study has provided a snapshot of the pattern of drug use in the gay community which compliments findings of the self-reported surveys and other studies from the same population. The information obtained will be helpful in guiding in designing harm reduction interventions in this community and for monitoring the impact of changes in legislation.

STUDY OF REUSABLE PHOTOSENSITIVE ELECTRON RECORDING MEDIA

DTIC Science & Technology

a low molecular weight polystyrene resin (Dow Ps-2) is most suitable. The first photodielectrically deformed picture of a course bar pattern is reported using CdSe:Cu powder dispersed in carnauba wax . (Author)

Determination of whey adulteration in milk powder by using laser induced breakdown spectroscopy.

PubMed

Bilge, Gonca; Sezer, Banu; Eseller, Kemal Efe; Berberoglu, Halil; Topcu, Ali; Boyaci, Ismail Hakki

2016-12-01

A rapid and in situ method has been developed to detect and quantify adulterated milk powder through adding whey powder by using laser induced breakdown spectroscopy (LIBS). The methodology is based on elemental composition differences between milk and whey products. Milk powder, sweet and acid whey powders were produced as standard samples, and milk powder was adulterated with whey powders. Based on LIBS spectra of standard samples and commercial products, species was identified using principle component analysis (PCA) method, and discrimination rate of milk and whey powders was found as 80.5%. Calibration curves were obtained with partial least squares regression (PLS). Correlation coefficient (R(2)) and limit of detection (LOD) values were 0.981 and 1.55% for adulteration with sweet whey powder, and 0.985 and 0.55% for adulteration with acid whey powder, respectively. The results were found to be consistent with the data from inductively coupled plasma - mass spectrometer (ICP-MS) method. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Studies on the brand traceability of milk powder based on NIR spectroscopy technology].

PubMed

Guan, Xiao; Gu, Fang-Qing; Liu, Jing; Yang, Yong-Jian

2013-10-01

Brand traceability of several different kinds of milk powder was studied by combining near infrared spectroscopy diffuse reflectance mode with soft independent modeling of class analogy (SIMCA) in the present paper. The near infrared spectrum of 138 samples, including 54 Guangming milk powder samples, 43 Netherlands samples, and 33 Nestle samples and 8 Yili samples, were collected. After pretreatment of full spectrum data variables in training set, principal component analysis was performed, and the contribution rate of the cumulative variance of the first three principal components was about 99.07%. Milk powder principal component regression model based on SIMCA was established, and used to classify the milk powder samples in prediction sets. The results showed that the recognition rate of Guangming milk powder, Netherlands milk powder and Nestle milk powder was 78%, 75% and 100%, the rejection rate was 100%, 87%, and 88%, respectively. Therefore, the near infrared spectroscopy combined with SIMCA model can classify milk powder with high accuracy, and is a promising identification method of milk powder variety.

Structural changes during milling of aluminum oxide powders

NASA Technical Reports Server (NTRS)

Ziepler, G.

1984-01-01

The mechanical activation of four fused corundum powders and a calcined Al2O3 powder was studied. The milled powders were characterized by their structural properties, crystallite size, and lattice distortions. Structural changes during milling, detected by X-ray line broadening analysis, gave information about the enhanced activity of the powders caused by the lattice distortions and by the decreasing crystallite size during milling. The structural changes during milling, under the same milling conditions, can be quite different for the same ceramic material, but with different characteristics in the as received state.

Menadione.

PubMed

Hassan, Ghada S

2013-01-01

This chapter includes the aspects of Menadione (vitamin K). The drug is synthesized by the use of itaconic acid obtained through Friedel-Craft condensation or by direct oxidation of the 2-methyl-1,4-naphthquinone. Vitamin K generally maintains healthy blood clotting and prevents excessive bleeding and hemorrhage, it is also important for maintaining healthy bone structure and for carbohydrate storage in the body. In addition, it is given to newborn babies born in hospitals to prevent the development of life-threatening bleeding caused by low prothrombin levels. The chapter discusses the drug metabolism and pharmacokinetics and presents various method of analysis of this drug such as compendial tests, electrochemical analysis, spectroscopic analysis, and chromatographic techniques of separation. It also discusses its physical properties such as solubility characteristics, X-ray powder diffraction pattern, and thermal methods of analysis. The chapter is concluded with a discussion on its biological properties such as activity, toxicity, and safety. Copyright © 2013 Elsevier Inc. All rights reserved.

Pulse Check: Trends in Drug Abuse January-June 2002 Reporting Period. Special Topic: A Look at Local Drug Markets.

ERIC Educational Resources Information Center

Meth, Marcia; Chalmers, Rebecca

The report aims to describe chronic drug users, emerging drugs, new routes of administration, varying use patterns, changing demand for treatment, drug-related criminal activity, drug markets, and shifts in supply and distribution patterns. Pulse Check regularly addresses four drugs of serious concern: heroin, crack cocaine/powder cocaine,…

SEM-EDX analysis of an unknown "known" white powder found in a shipping container from Peru

NASA Astrophysics Data System (ADS)

Albright, Douglas C.

2009-05-01

In 2008, an unknown white powder was discovered spilled inside of a shipping container of whole kernel corn during an inspection by federal inspectors in the port of Baltimore, Maryland. The container was detained and quarantined while a sample of the powder was collected and sent to a federal laboratory where it was screened using chromatography for the presence of specific poisons and pesticides with negative results. Samples of the corn kernels and the white powder were forwarded to the Food and Drug Administration, Forensic Chemistry Center for further analysis. Stereoscopic Light Microscopy (SLM), Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDX), and Polarized Light Microscopy/Infrared Spectroscopy (PLM-IR) were used in the analysis of the kernels and the unknown powder. Based on the unique particle analysis by SLM and SEM as well as the detection of the presence of aluminum and phosphorous by EDX, the unknown was determined to be consistent with reacted aluminum phosphide (AlP). While commonly known in the agricultural industry, aluminum phosphide is relatively unknown in the forensic community. A history of the use and acute toxicity of this compound along with some very unique SEM/EDX analysis characteristics of aluminum phosphide will be discussed.

Water-quality characteristics, including sodium-adsorption ratios, for four sites in the Powder River drainage basin, Wyoming and Montana, water years 2001-2004

USGS Publications Warehouse

Clark, Melanie L.; Mason, Jon P.

2006-01-01

The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, monitors streams throughout the Powder River structural basin in Wyoming and parts of Montana for potential effects of coalbed natural gas development. Specific conductance and sodium-adsorption ratios may be larger in coalbed waters than in stream waters that may receive the discharge waters. Therefore, continuous water-quality instruments for specific conductance were installed and discrete water-quality samples were collected to characterize water quality during water years 2001-2004 at four sites in the Powder River drainage basin: Powder River at Sussex, Wyoming; Crazy Woman Creek near Arvada, Wyoming; Clear Creek near Arvada, Wyoming; and Powder River at Moorhead, Montana. During water years 2001-2004, the median specific conductance of 2,270 microsiemens per centimeter at 25 degrees Celsius (?S/cm) in discrete samples from the Powder River at Sussex, Wyoming, was larger than the median specific conductance of 1,930 ?S/cm in discrete samples collected downstream from the Powder River at Moorhead, Montana. The median specific conductance was smallest in discrete samples from Clear Creek (1,180 ?S/cm), which has a dilution effect on the specific conductance for the Powder River at Moorhead, Montana. The daily mean specific conductance from continuous water-quality instruments during the irrigation season showed the same spatial pattern as specific conductance values for the discrete samples. Dissolved sodium, sodium-adsorption ratios, and dissolved solids generally showed the same spatial pattern as specific conductance. The largest median sodium concentration (274 milligrams per liter) and the largest range of sodium-adsorption ratios (3.7 to 21) were measured in discrete samples from the Powder River at Sussex, Wyoming. Median concentrations of sodium and sodium-adsorption ratios were substantially smaller in Crazy Woman Creek and Clear Creek, which tend to decrease sodium concentrations and sodium-adsorption ratios at the Powder River at Moorhead, Montana. Dissolved-solids concentrations in discrete samples were closely correlated with specific conductance values; Pearson's correlation coefficients were 0.98 or greater for all four sites. Regression equations for discrete values of specific conductance and sodium-adsorption ratios were statistically significant (p-values <0.001) at all four sites. The strongest relation (R2=0.92) was at the Powder River at Sussex, Wyoming. Relations on Crazy Woman Creek (R2=0.91) and Clear Creek (R2=0.83) also were strong. The relation between specific conductance and sodium-adsorption ratios was weakest (R2=0.65) at the Powder River at Moorhead, Montana; however, the relation was still significant. These data indicate that values of specific conductance are useful for estimating sodium-adsorption ratios. A regression model called LOADEST was used to estimate dissolved-solids loads for the four sites. The average daily mean dissolved-solids loads varied among the sites during water year 2004. The largest average daily mean dissolved-solids load was calculated for the Powder River at Moorhead, Montana. Although the smallest concentrations of dissolved solids were in samples from Clear Creek, the smallest average daily mean dissolved-solids load was calculated for Crazy Woman Creek. The largest loads occurred during spring runoff, and the smallest loads occurred in late summer, when streamflows typically were smallest. Dissolved-solids loads may be smaller than average during water years 2001-2004 because of smaller than average streamflow as a result of drought conditions.

Photoluminescent spectroscopy measurements in nanocrystalline praseodymium doped zirconia powders

NASA Astrophysics Data System (ADS)

Ramos-Brito, F.; Murrieta S, H.; Hernández A, J.; Camarillo, E.; García-Hipólito, M.; Martínez-Martínez, R.; Álvarez-Fragoso, O.; Falcony, C.

2006-05-01

Praseodymium doped zirconia powder (ZrO2: (0.53 at%) Pr3+) was prepared by a co-precipitation technique and annealed in air at a temperature Ta = 950 °C. The x-ray diffraction pattern shows a nanocrystalline structure composed of 29.6% monoclinic and 70.4% cubic-tetragonal phases. Medium infrared and Raman analysis confirms the monoclinic/cubic-tetragonal crystalline structure and proves the absence of praseodymium aggregates in the material. Photoluminescent spectroscopy over excitations of 457.9 and 514.9 nm (at 20 K), shows two emission spectra composed of many narrow peaks in the visible-near infrared region (VIS-NIR) of the electromagnetic spectrum, associated with 4f inter-level electronic transitions in praseodymium ions incorporated in the zirconia. Excitation and emission spectra show the different mechanisms of the direct and non-direct excitation of the dopant ion (Pr3+), and the preferential relaxation of the material by charge transfer from the host (zirconia) to the 4f5d band and the 4f inter-level of the dopant ion (Pr3+). No evidence of energy transfer from the host to the dopant was observed.

Crystal structure of paliperidone palmitate (INVEGA SUSTENNA®), C39H57FN4O4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaduk, James A.; Dmitrienko, Artem O.; Gindhart, Amy M.

2017-08-29

The crystal structure of paliperidone palmitate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Paliperidone palmitate crystallizes in space groupP2 1/c(#14) witha= 34.415 40(35),b= 10.093 49(7),c= 10.904 92(9) Å,β= 94.3917(9)°,V= 3776.94(6) Å 3, andZ= 4. The conformation of the paliperidone fragment differs from that of the parent compound. The palmitate chain exhibits a slight twist close to the ester group. Several C–H•••O hydrogen bonds contribute to the crystal packing, which is dominated by van der Waals interactions. The powder pattern is included in the Powder Diffraction File™ as entry 00-066-1614.

Studies on aluminium leaching from cookware in tea and coffee and estimation of aluminium content in toothpaste, baking powder and paan masala.

PubMed

Rajwanshi, P; Singh, V; Gupta, M K; Kumari, V; Shrivastav, R; Ramanamurthy, M; Dass, S

1997-01-30

Studies were conducted in order to assess the level of aluminium (Al) in samples of Indian tea, coffee, toothpaste, paan masala (mouth freshener) and baking powder. Leaching of Al from cookware while preparing tea and coffee was also studied. Experiments were also conducted to study the sequential leaching of Al from cookware by preparing tea and coffee in the presence of standard size Al sheets (coupons). A small amount of Al was found to have leached from coupons during preparation of tea. Tea leaves, were found to be a rich source of Al and a maximum of 2.2% Al is extracted in tea infusions. Coffee powder on the other hand was not found to be a rich source of Al. Baking powder was found to be a rich source of Al and 1 kg of cake prepared with 1-3 teaspoon of baking powder may contain 2-12.7 mg of Al in each serving (25 g). Toothpaste also contains a significant quantity of Al, more so, when packed in Al tubes. Ingestion pattern of Al from these items by humans is also discussed.

Experimental Evidence of Negative Linear Compressibility in the MIL-53 Metal-organic Framework Family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serra-Crespo, Pablo; Dikhtiarenko, Alla; Stavitski, Eli

Here we report a series of powder X-ray diffraction experiments performed on the soft porous crystals MIL-53(Al) and NH 2-MIL-53(Al) in a diamond anvil cell under different pressurization media. Systematic refinements of the obtained powder patterns demonstrate that these materials expand along a specific direction while undergoing total volume reduction under an increasing hydrostatic pressure. Our results confirm for the first time the negative linear compressibility behaviour of this family of materials, recently predicted from quantum chemical calculations.

Experimental evidence of negative linear compressibility in the MIL-53 metal–organic framework family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serra-Crespo, Pablo; Dikhtiarenko, Alla; Stavitski, Eli

Here we report a series of powder X-ray diffraction experiments performed on the soft porous crystals MIL-53(Al) and NH 2-MIL-53(Al) in a diamond anvil cell under different pressurization media. Systematic refinements of the obtained powder patterns demonstrate that these materials expand along a specific direction while undergoing total volume reduction under an increasing hydrostatic pressure. The results confirm for the first time the negative linear compressibility behaviour of this family of materials, recently predicted from quantum chemical calculations.

Experimental Evidence of Negative Linear Compressibility in the MIL-53 Metal-Organic Framework Family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serra-Crespo, Pablo; Dikhtiarenko, Alla; Stavitski, Eli

Here, we report a series of powder X-ray diffraction experiments performed on the soft porous crystals MIL-53(Al) and NH 2-MIL-53(Al) in a diamond anvil cell under different pressurization media. Systematic refinements of the obtained powder patterns demonstrate that these materials expand along a specific direction while undergoing total volume reduction under an increasing hydrostatic pressure. Our results confirm for the first time the negative linear compressibility behaviour of this family of materials, recently predicted from quantum chemical calculations.

Experimental evidence of negative linear compressibility in the MIL-53 metal–organic framework family

DOE PAGES

Serra-Crespo, Pablo; Dikhtiarenko, Alla; Stavitski, Eli; ...

2014-03-24

Here we report a series of powder X-ray diffraction experiments performed on the soft porous crystals MIL-53(Al) and NH 2-MIL-53(Al) in a diamond anvil cell under different pressurization media. Systematic refinements of the obtained powder patterns demonstrate that these materials expand along a specific direction while undergoing total volume reduction under an increasing hydrostatic pressure. The results confirm for the first time the negative linear compressibility behaviour of this family of materials, recently predicted from quantum chemical calculations.

Spectral analysis of allogeneic hydroxyapatite powders

NASA Astrophysics Data System (ADS)

Timchenko, P. E.; Timchenko, E. V.; Pisareva, E. V.; Vlasov, M. Yu; Red'kin, N. A.; Frolov, O. O.

2017-01-01

In this paper we discuss the application of Raman spectroscopy to the in vitro analysis of the hydroxyapatite powder samples produced from different types of animal bone tissue during demineralization process at various acid concentrations and exposure durations. The derivation of the Raman spectrum of hydroxyapatite is attempted by the analysis of the pure powders of its known constituents. Were experimentally found spectral features of hydroxyapatite, based on analysis of the line amplitude at wave numbers 950-965 cm-1 ((PO4)3- (ν1) vibration) and 1065-1075 cm-1 ((CO3)2-(ν1) B-type replacement). Control of physicochemical properties of hydroxyapatite was carried out by Raman spectroscopy. Research results are compared with an infrared Fourier spectroscopy.

Effects of milling media on the fabrication of melt-derived bioactive glass powder for biomaterial application

NASA Astrophysics Data System (ADS)

Ibrahim, Nurul Farhana; Mohamad, Hasmaliza; Noor, Siti Noor Fazliah Mohd

2016-12-01

The present work aims to study the effects of using different milling media on bioactive glass produced through melt-derived method for biomaterial application. The bioactive glass powder based on SiO2-CaO-Na2O-P2O5 system was fabricated using two different types of milling media which are tungsten carbide (WC) and zirconia (ZrO2) balls. However, in this work, no P2O5 was added in the new composition. XRF analysis indicated that tungsten trioxide (WO3) was observed in glass powder milled using WC balls whereas ZrO2 was observed in glass powder milled using ZrO2 balls. Amorphous structure was detected with no crystalline peak observed through XRD analysis for both glass powders. FTIR analysis confirmed the formation of silica network with the existence of functional groups Si-O-Si (bend), Si-O-Si (tetrahedral) and Si-O-Si (stretch) for both glass powders. The results revealed that there was no significant effect of milling media on amorphous silica network glass structure which shows that WC and zirconia can be used as milling media for bioactive glass fabrication without any contamination. Therefore, the fabricated BG can be tested safely for bioactivity assessment in biological fluids environment.

Room Temperature Magnetic Behavior In Nanocrystalline Ni-Doped Zro2 By Microwave-Assisted Polyol Synthesis

NASA Astrophysics Data System (ADS)

Parimita Rath, Pragyan; Parhi, Pankaj Kumar; Ranjan Panda, Sirish; Priyadarshini, Barsharani; Ranjan Sahoo, Tapas

2017-08-01

This article, deals with a microwave-assisted polyol method to demonstrate a low temperature route < 250°C, to prepare a high temperature cubic zirconia phase. Powder XRD pattern shows broad diffraction peaks suggesting nanometric size of the particles. Magnetic behavior of 1-5 at% Ni doped samples show a threshold for substitutional induced room temperature ferromagnetism up to 3 at% of Ni. TGA data reveals that Ni-doped ZrO2 polyol precursors decompose exothermically below 300°C. IR data confirms the reduction of Zr(OH)4 precipitates to ZrO2, in agreement with the conclusions drawn from the TGA analysis.

On the application of magic echo cycles for quadrupolar echo spectroscopy of spin-1 nuclei.

PubMed

Mananga, E S; Roopchand, R; Rumala, Y S; Boutis, G S

2007-03-01

Magic echo cycles are introduced for performing quadrupolar echo spectroscopy of spin-1 nuclei. An analysis is performed via average Hamiltonian theory showing that the evolution under chemical shift or static field inhomogeneity can be refocused simultaneously with the quadrupolar interaction using these cycles. Due to the higher convergence in the Magnus expansion, with sufficient RF power, magic echo based quadrupolar echo spectroscopy outperforms the conventional two pulse quadrupolar echo in signal to noise. Experiments highlighting a signal to noise enhancement over the entire bandwidth of the quadrupolar pattern of a powdered sample of deuterated polyethelene are shown.

Analysis of dynamic characteristics of fluid force induced by labyrinth seal

NASA Technical Reports Server (NTRS)

Iwatsubo, T.; Kawai, R.; Kagawa, N.; Kakiuchi, T.; Takahara, K.

1984-01-01

Flow patterns of the labyrinth seal are experimentally investigated for making a mathematical model of labyrinth seal and to obtain the flow induced force of the seal. First, the flow patterns in the labyrinth chamber are studied on the circumferential flow using bubble and on the cross section of the seal chamber using aluminum powder as tracers. And next, the fluid force and its phase angle are obtained from the measured pressure distribution in the chamber and the fluid force coefficients are derived from the fluid force and the phase angle. Those are similar to the expression of oil film coefficients. As a result, it is found that the vortices exist in the labyrinth chambers and its center moves up and down periodically. The pressure drop is biggest in the first stage of chambers and next in the last stage of chambers.

Solid state of CG-400549, a novel FabI inhibitor: characterization, dissolution, transformation.

PubMed

Kim, Bo-Yeon; Sohn, Young-Taek

2011-05-01

The polymorphic and pseudopolymorphic forms of CG-400549, a novel FabI inhibitor with potent in vivo activity were prepared and characterized by differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD) and thermogravimetric analysis (TG). Seven crystal forms of CG-400549, one anhydrate and six solvates, have been isolated by recrystallization and the DSC and PXRD patterns of the seven crystal forms of CG-400549 were different respectively. The dissolution patterns of these seven crystal forms of CG-400549 were studied and they showed significant differences in the dissolution rate. After storage of 1 month at 0% RH (silica gel, 20°C), 52% RH (saturated solution of Na(2)Cr(2)O(7)2H(2)O/20°C) and 95% RH (saturated solution of Na(2)HPO(4)/20°C), all crystal forms were not transformed.

Micro structrual characterization and analysis of ball milled silicon carbide

NASA Astrophysics Data System (ADS)

Madhusudan, B. M.; Raju, H. P.; Ghanaraja., S.

2018-04-01

Mechanical alloying has been one of the prominent methods of powder synthesis technique in solid state involving cyclic deformation, cold welding and fracturing of powder particles. Powder particles in this method are subjected to greater mechanical deformation due to the impact of ball-powder-ball and ball-powder-container collisions that occurs during mechanical alloying. Strain hardening and fracture of particles decreases the size of the particles and creates new surfaces. The objective of this Present work is to use ball milling of SiC powder for different duration of 5, 10, 15 and 20 hours by High energy planetary ball milling machine and to evaluate the effect of ball milling on SiC powder. Micro structural Studies using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and EDAX has been investigated.

Influence of small particles inclusion on selective laser melting of Ti-6Al-4V powder

NASA Astrophysics Data System (ADS)

Gong, Haijun; Dilip, J. J. S.; Yang, Li; Teng, Chong; Stucker, Brent

2017-12-01

The particle size distribution and powder morphology of metallic powders have an important effect on powder bed fusion based additive manufacturing processes, such as selective laser melting (SLM). The process development and parameter optimization require a fundamental understanding of the influence of powder on SLM. This study introduces a pre-alloyed titanium alloy Ti-6Al-4V powder, which has a certain amount of small particles, for SLM. The influence of small particle inclusion is investigated through microscopy of surface topography, elemental and microstructural analysis, and mechanical testing, compared to the Ti-6Al-4V powder provided by SLM machine vendor. It is found that the small particles inclusion in Ti-6Al-4V powder has a noticeable effect on extra laser energy absorption, which may develop imperfections and deteriorate the SLM fatigue performance.

Influence of grinding on service properties of VT-22 powder applied in additive technologies

NASA Astrophysics Data System (ADS)

Zakharov, M. N.; Rybalko, O. F.; Romanova, O. V.; Gelchinskiy, B. R.; Il'inykh, S. A.; Krashaninin, V. A.

2017-01-01

Powder of titanium alloy (VT-22) produced by plasma-spraying was subjected to grinding to obtain powder with size less 100 microns. These powders were sprayed by plasma unit using two types of gases, namely, air and air with methane (spraying in water and sputtering of coating on steel support). Influence of grinding time on yield of powder of required fraction was studied. Morphology and phase composition of the grinded powder and plasma sprayed one were under investigation. In the result of experiments, it appears that the grinding time genuinely influences the chemical and phase compositions, but there is no effect on physical-processing properties. For powders after plasma spraying some changes of non-metal elements content were detected by chemical analysis. Using gaseous mixture of air and methane in plasma spraying unit leads to formation of a new phase in the powder according X-ray diffraction data.

Bimodal metal micro-nanopowders for powder injection molding

NASA Astrophysics Data System (ADS)

Pervikov, Aleksandr; Rodkevich, Nikolay; Glazkova, Elena; Lerner, Marat

2017-12-01

The paper studies a bimodal metal powder composition designed to prepare feedstock for powder injection molding, as well as microstructure and porosity of sintered pats. Two kinds of metal powder compositions are used, in particular, a mixture of micro- and nanopowders and a bimodal powder prepared with dispersion of steel wire. The feedstock is prepared by mixing a bimodal metal powder composition with acetylacetone and paraffin wax. The microstructure of the debound parts is observed by scanning electron microscopy. The sintered parts are characterized by density measurements and metallographic analysis. The technique of the metal powder composition proves to affect the characteristics of sintered parts. Nanoparticles are shown in the interstitial spaces among the microparticles upon mixing micro- and nanopowders, but the regular distribution of nanoparticles on the surface of microparticles is observed in the bimodal powder providing the reduction of the porosity of sintered parts and increasing the density to the proper density of steel.

Assessment of ecological conditions and potential effects of water produced from coalbed natural gas development on biological communities in streams of the Powder River structural basin, Wyoming and Montana, 2005-08

USGS Publications Warehouse

Peterson, David A.; Clark, Melanie L.; Foster, Katharine; Wright, Peter R.; Boughton, Gregory K.

2010-01-01

Ongoing development of coalbed natural gas in the Powder River structural basin in Wyoming and Montana led to formation of an interagency task group to address concerns about the effects of the resulting production water on biological communities in streams of the area. The interagency task group developed a monitoring plan and conducted sampling of macroinvertebrate, algal, and fish communities at 47 sites during 2005-08 to document current ecological conditions and determine existing and potential effects of water produced from coalbed natural gas development on biological communities. Macroinvertebrate, algal, and fish community composition varied between drainage basins, among sites within drainage basins, and by year. Macroinvertebrate communities of the main-stem Tongue River were characterized by higher taxa richness and higher abundance of Ephemeroptera, for example, compared to macroinvertebrate communities in plains tributaries of the Tongue River and the main-stem Powder River. Fish communities of the Tongue River were characterized by higher taxa richness and abundance of introduced species compared to the Powder River where native species were dominant. Macroinvertebrate community metric values from sites in the middle reach of the main-stem Powder River, from below Willow Creek to below Crazy Woman Creek, differed from metric values in the upper and lower reaches of the Powder River. Metrics indicative of communitywide differences included measures of taxa richness, relative abundance, feeding mode, and tolerance. Some of the variation in the macroinvertebrate communities could be explained by variation in environmental variables, including physical (turbidity, embeddedness, bed substrate size, and streamflow) and chemical (alkalinity and specific conductance) variables. Of these environmental variables, alkalinity was the best indicator of coalbed natural gas development because of the sodiumbicarbonate signature of the production water. Algal samples from the main-stem Powder River generally confirmed the pattern observed in the macroinvertebrate communities. Algal communities at sites in the middle reach of the Powder River commonly were characterized by dominance by a single taxon and by low biovolume of algae compared to other sites. In contrast to the macroinvertebrate and algal communities, species richness of fish communities was highest in the middle reach of the Powder River. Although a few significant differences in fish metrics were determined along the main-stem Powder River, the differences did not correspond to the pattern observed for the macroinvertebrate and algae communities. Differences in biological communities were noted between years, potentially due to the effects of drought. Macroinvertebrate community metrics, such as Diptera taxa richness, were significantly different in the severe drought year of 2006 from metric values in 2005 and 2007-08. Waterquality data collected during the study indicated that, with few exceptions, water-quality constituents generally did not exceed State or Federal acute and chronic criteria for the protection of aquatic life.

Surveying Clay Mineral Diversity in the Murray Formation, Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Bristow, T. F.; Blake, D. F.; Vaniman, D. T.; Chipera, S. J.; Rampe, E. B.; Grotzinger, J. P.; McAdam, A. C.; Ming, D. W.; Morrison, S. M.; Yen, A. S.;

Sequential changes of main components in different kinds of milk powders using two-dimensional infrared correlation analysis

NASA Astrophysics Data System (ADS)

Zhou, Qun; Sun, Su-Qin; Yu, Lu; Xu, Chang-Hua; Noda, Isao; Zhang, Xin-Rong

2006-11-01

Infrared (IR) spectroscopy and two-dimensional (2D) correlation IR spectroscopy are shown to offer some information about stability and shelf life of milk powders without separation and extraction of individual components in this paper. Temperature has been chosen as the perturbation to monitor the infrared behavior of various milk powders, namely, whole milk powder (WMP), sweet whole milk powder (Sweet WMP), low-fat milk powder (LFMP), and skim milk powder (SMP). The sequential order of changes in protein, fat and carbohydrates (mainly lactose) in milk powders is studied for the first time. The protein changes before the sucrose in WMP, whereas the sucrose changes before the protein in Sweet WMP under temperature perturbation. It is also found that in SMP, carbohydrate changes prior to protein whereas in LFMP and WMP protein changes first as the temperature is increased. The conclusion can provide some useful reference to understand the thermal stability of milk powders.

Upgrades and Modifications of the NASA Ames HFFAF Ballistic Range

NASA Technical Reports Server (NTRS)

Bogdanoff, David W.; Wilder, Michael C.; Cornelison, Charles J.; Perez, Alfredo J.

2017-01-01

The NASA Ames Hypervelocity Free Flight Aerodynamics Facility ballistic range is described. The various configurations of the shadowgraph stations are presented. This includes the original stations with film and configurations with two different types of digital cameras. Resolution tests for the 3 shadowgraph station configurations are described. The advantages of the digital cameras are discussed, including the immediate availability of the shadowgraphs. The final shadowgraph station configuration is a mix of 26 Nikon cameras and 6 PI-MAX2 cameras. Two types of trigger light sheet stations are described visible and IR. The two gunpowders used for the NASA Ames 6.251.50 light gas guns are presented. These are the Hercules HC-33-FS powder (no longer available) and the St. Marks Powder WC 886 powder. The results from eight proof shots for the two powders are presented. Both muzzle velocities and piston velocities are 5 9 lower for the new St. Marks WC 886 powder than for the old Hercules HC-33-FS powder (no longer available). The experimental and CFD (computational) piston and muzzle velocities are in good agreement. Shadowgraph-reading software that employs template-matching pattern recognition to locate the ballistic-range model is described. Templates are generated from a 3D solid model of the ballistic-range model. The accuracy of the approach is assessed using a set of computer-generated test images.

Synthesis of ferrite and nickel ferrite nanoparticles using radio-frequency thermal plasma torch

NASA Astrophysics Data System (ADS)

Son, S.; Taheri, M.; Carpenter, E.; Harris, V. G.; McHenry, M. E.

2002-05-01

Nanocrystalline (NC) ferrite powders have been synthesized using a 50 kW-3 MHz rf thermal plasma torch for high-frequency soft magnet applications. A mixed powder of Ni and Fe (Ni:Fe=1:2), a NiFe permalloy powder with additional Fe powder (Ni:Fe=1:2), and a NiFe permalloy powder (Ni:Fe=1:1) were used as precursors for synthesis. Airflow into the reactor chamber was the source of oxygen for oxide formation. XRD patterns clearly show that the precursor powders were transformed into NC ferrite particles with an average particle size of 20-30 nm. SEM and TEM studies indicated that NC ferrite particles had well-defined polygonal growth forms with some exhibiting (111) faceting and many with truncated octahedral and truncated cubic shapes. The Ni content in the ferrite particles was observed to increase in going from mixed Ni and Fe to mixed permalloy and iron and finally to only permalloy starting precursor. The plasma-torch synthesized ferrite materials using exclusively the NiFe permalloy precursor had 40%-48% Ni content in the Ni-ferrite particle, differing from the NiFe2O4 ideal stoichiometry. EXAFS was used to probe the cation coordination in low Ni magnetite species. The coercivity and Neel temperature of the high Ni content ferrite sample were 58 Oe and ˜590 °C, respectively.

Effects of packaging materials on the aroma stability of Thai 'tom yam' seasoning powder as determined by descriptive sensory analysis and gas chromatography-mass spectrometry.

PubMed

Leelaphiwat, Pattarin; Harte, Janice B; Auras, Rafael A; Ong, Peter Kc; Chonhenchob, Vanee

2017-04-01

Changes in the aroma characteristics of Thai 'tom yam' seasoning powder, containing lemongrass, galangal and kaffir lime leaf, as affected by different packaging materials were assessed using quantitative descriptive analysis (QDA) and gas chromatography-mass spectrometry (GC-MS). The descriptive aroma attributes for lemongrass, galangal and kaffir lime leaf powders were developed by the QDA panel. The mixed herb and spice seasoning powder was kept in glass jars closed with different packaging materials (Nylon 6, polyethylene terephthalate (PET) and polylactic acid (PLA)) stored at 38 °C (accelerated storage condition), and evaluated by the trained QDA panel during storage for 49 days. The descriptive words for Thai 'tom yam' seasoning powder developed by the trained panelists were lemongrass, vinegary and leafy for lemongrass, galangal and kaffir lime leaf dried powder, respectively. The aroma intensities significantly (P ≤ 0.05) decreased with increased storage time. However, the intensity scores for aroma attributes were not significantly (P > 0.05) different among the packaging materials studied. The major components in Thai 'tom yam' seasoning powder, quantified by GC-MS, were estragole, bicyclo[3.1.1]heptane, β-bisabolene, benzoic acid and 2-ethylhexyl salicylate. The concentrations of major aroma compounds significantly (P ≤ 0.05) decreased with storage time. Aroma stability of Thai 'tom yam' powder can be determined by descriptive sensory evaluation and GC-MS analysis. Nylon, PET and PLA exhibited similar aroma barrier properties against key aroma compounds in Thai 'tom yam'. This information can be used for prediction of aroma loss through packaging materials during storage of Thai 'tom yam'. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

The suitability of common compressibility equations for characterizing plasticity of diverse powders.

PubMed

Paul, Shubhajit; Sun, Changquan Calvin

2017-10-30

The analysis of powder compressibility data yields useful information for characterizing compaction behavior and mechanical properties of powders, especially plasticity. Among the many compressibility equations proposed in powder compaction research, the Heckel equation and the Kawakita equation are the most commonly used, despite their known limitations. Systematic evaluation of the performance in analyzing compressibility data suggested the Kuentz-Leuenberger equation is superior to both the Heckel equation and the Kawakita equation for characterizing plasticity of powders exhibiting a wide range of mechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation on the structural, magnetic and magnetocaloric properties of nanocrystalline Pr-deficient Pr1-xSrxMnO3-δ manganites

NASA Astrophysics Data System (ADS)

Arun, B.; Athira, M.; Akshay, V. R.; Sudakshina, B.; Mutta, Geeta R.; Vasundhara, M.

2018-02-01

We have investigated the structural, magnetic and magnetocaloric properties of nanocrystalline Pr-deficient Pr1-xSrxMnO3-δ Perovskite manganites. Rietveld refinement of the X-ray powder diffraction patterns confirms that all the studied compounds have crystallized into an orthorhombic structure with Pbnm space group. Transmission electron microscopy analysis reveals nanocrystalline compounds with crystallite size less than 50 nm. The selected area electron diffraction patterns reveal the highly crystalline nature of the compounds and energy dispersive X-ray spectroscopic analysis shows that the obtained compositions are nearly identical with the nominal one. The oxygen stoichiometry is estimated by iodometric titration method and stoichiometric compositions are confirmed by X-ray Fluorescence Spectrometry analysis. A large bifurcation is observed in the ZFC/FC curves and Arrott plots not show a linear relation but have a convex curvature nature. The temperature dependence of inverse magnetic susceptibility at higher temperature confirms the existence of ferromagnetic clusters. The experimental results reveal that the reduction of crystallite size to nano metric scale in Pr-deficient manganites adversely influences structural, magnetic and magnetocaloric properties as compared to its bulk counterparts reported earlier.

Modified Bridgman-Stockbarger growth and characterization of LiInSe{sub 2} single crystal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vijayakumar, P., E-mail: ramasamyp@ssn.edu.in; Magesh, M., E-mail: ramasamyp@ssn.edu.in; Arunkumar, A., E-mail: ramasamyp@ssn.edu.in

2014-04-24

The LiInSe{sub 2} polycrystalline materials were successfully synthesized from melt and temperature oscillation method. 8 mm diameter and 32 mm length single crystal was grown from Bridgman-Stockbarger method with steady ampoule rotation. Crystalline phase was confirmed by powder XRD pattern. Thermo gravimetric and differential thermal analysis confirms that the melting point of the grown crystal is 897°C. Rutherford backscattering analysis (RBS) gives the crystal composition as Li{sub 0.8}In{sub 1.16}Se{sub 2.04}. The crystalline perfection of the grown crystal was analyzed by High resolution X-ray diffraction measurements (HRXRD). The electrical properties of the grown crystal were analyzed by Hall effect measurements andmore » it confirms the n-type semiconducting nature.« less

Remote analysis of planetary soils: X-ray diffractometer development

NASA Technical Reports Server (NTRS)

Gregory, J. C.

1973-01-01

A system is described suitable for remote low power mineralogical analysis of lunar, planetary, or asteroid soils. It includes an X-ray diffractometer, fluorescence spectrometer, and sample preparation system. A one Curie Fe-55 source provides a monochromatic X-ray beam of 5.9 keV. Seeman-Bohlin or focusing geometry is employed in the camera, allowing peak detection to proceed simultaneously at all angles and obviating the need for moving parts. The detector system is an array of 500-600 proportional counters with a wire-spacing of 1 mm. An electronics unit comprising preamplifier, postamplifier, window discriminators, and storage flipflops requiring only 3.5 milliwatts was designed and tested. Total instrument power is less than 5 watts. Powder diffraction patterns using a flat breadboard multiwire counter were recorded.

Identification and evaluation of composition in food powder using point-scan Raman spectral imaging

USDA-ARS?s Scientific Manuscript database

This study used Raman spectral imaging coupled with self-modeling mixture analysis (SMA) for identification of three components mixed into a complex food powder mixture. Vanillin, melamine, and sugar were mixed together at 10 different concentration levels (spanning 1% to 10%, w/w) into powdered non...

Effect of powder compaction on radiation-thermal synthesis of lithium-titanium ferrites

NASA Astrophysics Data System (ADS)

Surzhikov, A. P.; Lysenko, E. N.; Vlasov, V. A.; Malyshev, A. V.; Korobeynikov, M. V.; Mikhailenko, M. A.

2017-01-01

Effect of powder compaction on the efficiency of thermal and radiation-thermal synthesis of lithium-substituted ferrites was investigated by X-Ray diffraction and specific magnetization analysis. It was shown that the radiation-thermal heating of compacted powder reagents mixture leads to an increase in efficiency of lithium-titanium ferrites synthesis.

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

PubMed

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

2014-01-27

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. Copyright © 2013 Elsevier B.V. All rights reserved.

Glass transition in ferroic glass K x (ND4)1-x D2PO4: a complete x-ray diffraction line shape analysis

NASA Astrophysics Data System (ADS)

Ranjan Choudhury, Rajul; Chitra, R.; Jayakrishnan, V. B.

2016-03-01

Quenching of dynamic disorder in glassy systems is termed as the glass transition. Ferroic glasses belong to the class of paracrystalline materials having crystallographic order in-between that of a perfect crystal and amorphous material, a classic example of ferroic glass is the solid solution of ferroelectric deuterated potassium dihydrogen phosphate and antiferroelectric deuterated ammonium dihydrogen phosphate. Lowering temperature of this ferroic glass can lead to a glass transition to a quenched disordered state. The subtle atomic rearrangement that takes place at such a glass transition can be revealed by careful examination of the temperature induced changes occurring in the x-ray powder diffraction (XRD) patterns of these materials. Hence we report here results of a complete diffraction line shape analysis of the XRD patterns recorded at different temperatures from deuterated mixed crystals DK x A1-x DP with mixing concentration x ranging as 0 < x < 1. Changes observed in diffraction peak shapes have been explained on the basis of structural rearrangements induced by changing O-D-O hydrogen bond dynamics in these paracrystals.

Dietary patterns of children and socioeconomical, behavioral and maternal determinants

PubMed Central

Villa, Julia Khéde Dourado; Santos, Thanise Sabrina Souza; Ribeiro, Andréia Queiroz; Silva, Angélica Ribeiro e; da Rocha Sant'Ana, Luciana Ferreira; Pessoa, Milene Cristine

2015-01-01

Abstract Objective: To identify dietary patterns of children and to verify their association with socio-economical, behavioral and maternal determinants. Methods: A cross-sectional study with a random sample of 328 children aged 8 and 9 years. Dietary intake was assessed by food records in three nonconsecutive days and measured in grams of food groups and nutrients. Factor analysis and subsequent orthogonal rotation (varimax) were used to determine dietary patterns. Ordinal logistic regression was used to assess associations between dietary patterns and the studied determinants. Results: Five dietary patterns were observed: “Traditional,” “Sweetened beverages and snacks,” “Monotonous,” “Healthy” and “Egg-dairy.” A higher maternal level of education was directly associated with “Sweetened beverages and snacks” and “Egg-dairy' standards. Low income children who were submitted to greater food restriction by parents/guardians followed the more “Traditional” standard, represented by the consumption of rice, beans, vegetables, cooked roots and tubers and red meat. The “Monotonous” pattern, represented by a high consumption of milk and chocolate powder, was most followed by children from the middle class. Children living in rural areas consumed more foods from the “Egg-dairy” pattern, when compared to those from the urban area. Conclusions: Dietary patterns of children were associated with family socioeconomic status, maternal level of education, practice of food restriction by parents/guardians and location of residence in urban or rural area. Better socioeconomic conditions contributed to a more nutritionally inadequate dietary pattern. PMID:26163945

Crystallisation of alpha-crustacyanin, the lobster carapace astaxanthin-protein: results from EURECA

NASA Astrophysics Data System (ADS)

Zagalsky, P. F.; Wright, C. E.; Parsons, M.

1995-08-01

Crystallisation of alpha-crustacyanin, the lobster carapace astaxanthin-protein was attempted under microgravity conditions in EURECA satellite using liquid-liquid diffusion with polyethyleneglycol (PEG) as precipitant; in a second reaction chamber phenol and dioxan were used as additives to prevent composite crystal growth. Crystals of alpha-crustacyanin grown under microgravity from PEG were larger than those grown terrestrially in the same apparatus under otherwise identical conditions. On retrieval, the crystals from PEG were shown to be composite and gave a powder diffraction pattern. The second reaction chamber showed leakage on retrieval and had also been subjected to rapid temperature variation during flight. Crystal fragments were nevertheless recovered but showed a powder diffraction pattern. It is concluded, certainly for liquid-liquid diffusion using PEG alone, that, for crustacyanin, although microgravity conditions resulted in an increase in dimensions of crystals, a measurable improvement in molecular ordering was not achieved.

Investigation of using wavelet analysis for classifying pattern of cyclic voltammetry signals

NASA Astrophysics Data System (ADS)

Jityen, Arthit; Juagwon, Teerasak; Jaisuthi, Rawat; Osotchan, Tanakorn

2017-09-01

Wavelet analysis is an excellent technique for data processing analysis based on linear vector algebra since it has an ability to perform local analysis and is able to analyze an unspecific localized area of a large signal. In this work, the wavelet analysis of cyclic waveform was investigated in order to find the distinguishable feature from the cyclic data. The analyzed wavelet coefficients were proposed to be used as selected cyclic feature parameters. The cyclic voltammogram (CV) of different electrodes consisting of carbon nanotube (CNT) and several types of metal phthalocyanine (MPc) including CoPc, FePc, ZnPc and MnPc powders was used as several sets of cyclic data for various types of coffee. The mixture powder was embedded in a hollow Teflon rod and used as working electrodes. Electrochemical response of the fabricated electrodes in Robusta, blend coffee I, blend coffee II, chocolate malt and cocoa at the same concentrations was measured with scanning rate of 0.05V/s from -1.5 to 1.5V respectively to Ag/AgCl electrode for five scanning loops. The CV of blended CNT electrode with some MPc electrodes indicated the ionic interaction which can be the effect of catalytic oxidation of saccharides and/or polyphenol on the sensor surface. The major information of CV response can be extracted by using several mother wavelet families viz. daubechies (dB1 to dB3), coiflets (coiflet1), biorthogonal (Bior1.1) and symlets (sym2) and then the discrimination of these wavelet coefficients of each data group can be separated by principal component analysis (PCA). The PCA results indicated the clearly separate groups with total contribution more than 62.37% representing from PC1 and PC2.

Physical characteristics and aerosolization performance of insulin dry powders for inhalation prepared by a spray drying method.

PubMed

You, Yu; Zhao, Min; Liu, Guangli; Tang, Xing

2007-07-01

The objective of this study was to investigate the influence of formulation excipients on the physical characteristics and aerosolization performance of insulin dry powders for inhalation. Insulin dry powders were prepared by a spray drying technique using excipients such as sugars (trehalose, lactose and dextran), mannitol and amino acids (L-leucine, glycine and threonine). High performance liquid chromatography and the mouse blood glucose method were used for determination of the insulin content. The powder properties were determined and compared by scanning electron microscopy, thermo-gravimetric analysis and size distribution analysis by a time-of-flight technique. The in-vitro aerosolization behaviour of the powders was assessed with an Aerolizer inhaler using a twin-stage impinger. Powder yield and moisture absorption were also determined. Results showed that there was no noticeable change in insulin content in any of the formulations by both assay methods. All powders were highly wrinkled, with median aerodynamic diameters of 2-4 microm, and consequently suitable for pulmonary administration. The tapped density was reduced dramatically when glycine was added. The powders containing mannitol, with or without L-leucine, were less sensitive to moisture. The highest respirable fraction of 67.3 +/- 1.3% was obtained with the formulation containing L-leucine, in contrast to formulations containing glycine and threonine, which had a respirable fraction of 11.2 +/- 3.9% and 23.5 +/- 2.5%, respectively. In addition, powders with good physical properties were achieved by the combination of insulin and trehalose. This study suggests that L-leucine could be used to enhance the aerosolization behaviour of the insulin dry powders for inhalation, and trehalose could potentially be used as an excipient in the formulations.

Optical Properties of Natural Minerals in the Far-Infrared

NASA Astrophysics Data System (ADS)

Long, Larry Lavern

The reflectivity of natural mineral powders were measured in the far infrared. The complex indices of refraction were then determined by Kramers-Kronig analysis or dispersive analysis. The samples were constructed by pressing the powdered sample into a 13 mm diameter pellet. A few of the samples that were measured were kaolin, illite, and montmorillonite, clay samples that could not be obtained in large single crystals. For calcite and gypsum crystals a comparison between the single crystal measurements and powder measurements was done to determine the effect of sample preparation on the measured spectra.

Synthesis and electrical characterization of BaZr0.9Ho0.1O3-δ electrolyte ceramic for IT - SOFCs

NASA Astrophysics Data System (ADS)

Saini, Deepash S.; Singh, Lalit K.; Bhattacharya, D.

2018-04-01

A cost-effective modified combustion method using citric acid and glycine has recently been developed to synthesize high quality, and nanosized BaZr0.9Ho0.1O3 ceramic powder. BaZr0.9Ho0.1O3-δ ceramic powder was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). XRD pattern of BaZr0.9Ho0.1O3-δ ceramic sintered at 1600 °C has shown that pure phase of BaZr0.9Ho0.1O3-δ with cubic Pm3¯m space group symmetry. The transmission electron microscopic investigation has shown that the particle size of the powder calcined at 1100 °C was in the range 30-80 nm. The FESEM image of sintered pellet at 1600 °C for 4 h reveals porous nature of BaZr0.9Ho0.1O3-δ with 83.7 relative density. Impedance analysis reveal three type relaxations in the temperature range 250 °C to 500 °C as studied at different frequencies over 100 Hz to 1 MHz in air. The grain boundary conductivity of BaZr0.9Ho0.1O3-δ ceramic is found lower then grain (bulk) conductivity due to core-space charge layer behavior in grain boundary.

Establishing powder-handling workflow practices and standard operating procedures: compounding pharmacy and safety.

PubMed

Prince, Bryan; Lundevall, Jeremy

2014-01-01

This is an ongoing discussion and analysis of powder-handling safety in the compounding pharmacy laboratory that started in the November/December 2013 issue of the International Journal of Pharmaceutical Compounding. In the previous technical article, we established that most chemical powders handled during compounding procedures have an established occupational exposure limits and that powders are micronized during manipulation. All micronized powders handled on an open bench create health hazards to the technicians and create a potential for cross-contamination to the lab environment. Proper identification of the chemical hazard and established standard operating procedures in direct correlation to Good Lab Practices when working inside a powder hood will positively improve the compounding pharmacy's work environment.

Modified Chaihu Shugan Powder for Functional Dyspepsia: Meta-Analysis for Randomized Controlled Trial

PubMed Central

Yang, Nan; Jiang, Xuehua; Hu, Zhiqiang; Wang, Ling; Song, Minxian

2013-01-01

Context. Modified Chaihu Shugan powder (MCSP) is a popular traditional Chinese herbal formula for functional dyspepsia, which is revised from Chaihu Shugan San and recorded in a medical classic works of China. However, its role and effect in treating functional dyspepsia have not been well established. Objective. To assess the effect and safety of modified Chaihu Shugan powder for functional dyspepsia. Methods. We searched the published and unpublished studies up to August 2012. Only RCTs of modified Chaihu Shugan powder with or without prokinetic drugs versus prokinetic drugs in the patients diagnosed with functional dyspepsia were included. Results. Twenty-two clinical trials involving 1998 participants were included. There were evidences that modified Chaihu Shugan powder (RR = 1.20, 95%, CI 1.14 to 1.27) and modified Chaihu Shugan powder plus prokinetic drugs (RR = 1.18, 95%, CI 1.11 to 1.25) were significantly better treatment options than prokinetic drugs alone in improving symptoms. No serious adverse events were described in the included trials. Conclusions. This meta-analysis showed that modified Chaihu Shugan powder alone or in combination with prokinetic drugs might be more effective than prokinetic drugs alone. However, with poor methodological quality, all the included trials were at high risk of bias. Further large-scale high-quality trials are required for assessment. PMID:23762161

Cleansing orthodontic brackets with air-powder polishing: effects on frictional force and degree of debris.

PubMed

Leite, Brisa Dos Santos; Fagundes, Nathalia Carolina Fernandes; Aragón, Mônica Lídia Castro; Dias, Carmen Gilda Barroso Tavares; Normando, David

2016-01-01

Debris buildup on the bracket-wire interface can influence friction. Cleansing brackets with air-powder polishing can affect this process. The aim of this study was to evaluate the frictional force and amount of debris remaining on orthodontic brackets subjected to prophylaxis with air-powder polishing. Frictional force and debris buildup on the surface of 28 premolar brackets were evaluated after orthodontic treatment. In one hemiarch, each bracket was subjected to air-powder polishing (n = 14) for five seconds, while the contralateral hemiarch (n = 14) served as control. Mechanical friction tests were performed and images of the polished bracket surfaces and control surfaces were examined. Wilcoxon test was applied for comparative analysis between hemiarches at p < 0.05. Brackets that had been cleaned with air-powder polishing showed lower friction (median = 1.27 N) when compared to the control surfaces (median = 4.52 N) (p < 0.01). Image analysis showed that the control group exhibited greater debris buildup (median = 2.0) compared with the group that received prophylaxis with air-powder polishing (median = 0.5) (p < 0.05). Cleansing orthodontic brackets with air-powder polishing significantly reduces debris buildup on the bracket surface while decreasing friction levels observed during sliding mechanics.

Properties and Applications of High Emissivity Composite Films Based on Far-Infrared Ceramic Powder

PubMed Central

Xiong, Yabo; Huang, Shaoyun; Wang, Wenqi; Liu, Xinghai; Li, Houbin

2017-01-01

Polymer matrix composite materials that can emit radiation in the far-infrared region of the spectrum are receiving increasing attention due to their ability to significantly influence biological processes. This study reports on the far-infrared emissivity property of composite films based on far-infrared ceramic powder. X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray powder diffractometry were used to evaluate the physical properties of the ceramic powder. The ceramic powder was found to be rich in aluminum oxide, titanium oxide, and silicon oxide, which demonstrate high far-infrared emissivity. In addition, the micromorphology, mechanical performance, dynamic mechanical properties, and far-infrared emissivity of the composite were analyzed to evaluate their suitability for strawberry storage. The mechanical properties of the far-infrared radiation ceramic (cFIR) composite films were not significantly influenced (p ≥ 0.05) by the addition of the ceramic powder. However, the dynamic mechanical analysis (DMA) properties of the cFIR composite films, including a reduction in damping and shock absorption performance, were significant influenced by the addition of the ceramic powder. Moreover, the cFIR composite films showed high far-infrared emissivity, which has the capability of prolonging the storage life of strawberries. This research demonstrates that cFIR composite films are promising for future applications. PMID:29186047

Properties and Applications of High Emissivity Composite Films Based on Far-Infrared Ceramic Powder.

PubMed

Xiong, Yabo; Huang, Shaoyun; Wang, Wenqi; Liu, Xinghai; Li, Houbin

2017-11-29

Polymer matrix composite materials that can emit radiation in the far-infrared region of the spectrum are receiving increasing attention due to their ability to significantly influence biological processes. This study reports on the far-infrared emissivity property of composite films based on far-infrared ceramic powder. X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray powder diffractometry were used to evaluate the physical properties of the ceramic powder. The ceramic powder was found to be rich in aluminum oxide, titanium oxide, and silicon oxide, which demonstrate high far-infrared emissivity. In addition, the micromorphology, mechanical performance, dynamic mechanical properties, and far-infrared emissivity of the composite were analyzed to evaluate their suitability for strawberry storage. The mechanical properties of the far-infrared radiation ceramic (cFIR) composite films were not significantly influenced ( p ≥ 0.05) by the addition of the ceramic powder. However, the dynamic mechanical analysis (DMA) properties of the cFIR composite films, including a reduction in damping and shock absorption performance, were significant influenced by the addition of the ceramic powder. Moreover, the cFIR composite films showed high far-infrared emissivity, which has the capability of prolonging the storage life of strawberries. This research demonstrates that cFIR composite films are promising for future applications.

XPS and SEM analysis of the surface of gas atomized powder precursor of ODS ferritic steels obtained through the STARS route

NASA Astrophysics Data System (ADS)

Gil, E.; Cortés, J.; Iturriza, I.; Ordás, N.

2018-01-01

An innovative powder metallurgy route to produce ODS FS, named STARS, has succeeded in atomizing steel powders containing the oxide formers (Y and Ti) and, hence, avoids the mechanical alloying (MA) step to dissolve Y in the matrix. A metastable oxide layer forms at the surface of atomized powders and dissociates during HIP consolidation at high temperatures, leading to precipitation of more stable Y-Ti-O nanoparticles.

Effects of glucose and sucrose variants of the caries-promoting Diet 2000 on the feeding patterns and parotid glands of prematurely weaned rats.

PubMed

Redman, Robert S

2015-03-01

The hypothesis of this study was that feeding glucose instead of sucrose in the cariogenic Diet 2000 to rats weaned at age 18 days would result in greater light/dark differences in feeding activity and secretion and storage of parotid salivary enzymes. Diet 2000 and a stock commercial diet (controls) were prepared in pelleted and powdered forms, as the increased mastication required by pellets has been shown to support circadian rhythms in rats. Food jars were weighed at lights on and just prior to lights off daily. Rats were euthanized at 25 days and their parotid glands removed, weighed, and analyzed for specific activities of the salivary enzymes α-amylase and deoxyribonuclease I. Light/dark differences in feeding activity were strong in the rats fed the pelleted stock diet and both powdered and pelleted glucose 2000 diets, moderate with the pelleted sucrose 2000 diet, and not significant with the powdered sucrose 2000 and stock diets. Light/dark differences in the parotid salivary enzymes were strong with the powdered glucose 2000 diet and the pelleted forms of the glucose and sucrose 2000 and stock diets, and not significant with the powdered stock and sucrose 2000 diets. Caries reportedly is higher in sucrose than glucose fed to rats in the standard powdered form of Diet 2000, mainly due to the colonizing advantage Streptococcus mutans gains with sucrose. These results suggest that additional factors are more feeding during lights on and less stimulation of parotid salivary secretion with the sucrose powder. Published by Elsevier Ltd.

Denudation of metal powder layers in laser powder bed fusion processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Manyalibo J.; Guss, Gabe; Khairallah, Saad A.

Understanding laser interaction with metal powder beds is critical in predicting optimum processing regimes in laser powder bed fusion additive manufacturing of metals. In this work, we study the denudation of metal powders that is observed near the laser scan path as a function of laser parameters and ambient gas pressure. We show that the observed depletion of metal powder particles in the zone immediately surrounding the solidified track is due to a competition between outward metal vapor flux directed away from the laser spot and entrainment of powder particles in a shear flow of gas driven by a metalmore » vapor jet at the melt track. Between atmospheric pressure and ~10 Torr of Ar gas, the denuded zone width increases with decreasing ambient gas pressure and is dominated by entrainment from inward gas flow. The denuded zone then decreases from 10 to 2.2 Torr reaching a minimum before increasing again from 2.2 to 0.5 Torr where metal vapor flux and expansion from the melt pool dominates. In addition, the dynamics of the denudation process were captured using high-speed imaging, revealing that the particle movement is a complex interplay among melt pool geometry, metal vapor flow, and ambient gas pressure. The experimental results are rationalized through finite element simulations of the melt track formation and resulting vapor flow patterns. The results presented here represent new insights to denudation and melt track formation that can be important for the prediction and minimization of void defects and surface roughness in additively manufactured metal components.« less

Denudation of metal powder layers in laser powder bed fusion processes

DOE PAGES

Matthews, Manyalibo J.; Guss, Gabe; Khairallah, Saad A.; ...

2016-05-20

Understanding laser interaction with metal powder beds is critical in predicting optimum processing regimes in laser powder bed fusion additive manufacturing of metals. In this work, we study the denudation of metal powders that is observed near the laser scan path as a function of laser parameters and ambient gas pressure. We show that the observed depletion of metal powder particles in the zone immediately surrounding the solidified track is due to a competition between outward metal vapor flux directed away from the laser spot and entrainment of powder particles in a shear flow of gas driven by a metalmore » vapor jet at the melt track. Between atmospheric pressure and ~10 Torr of Ar gas, the denuded zone width increases with decreasing ambient gas pressure and is dominated by entrainment from inward gas flow. The denuded zone then decreases from 10 to 2.2 Torr reaching a minimum before increasing again from 2.2 to 0.5 Torr where metal vapor flux and expansion from the melt pool dominates. In addition, the dynamics of the denudation process were captured using high-speed imaging, revealing that the particle movement is a complex interplay among melt pool geometry, metal vapor flow, and ambient gas pressure. The experimental results are rationalized through finite element simulations of the melt track formation and resulting vapor flow patterns. The results presented here represent new insights to denudation and melt track formation that can be important for the prediction and minimization of void defects and surface roughness in additively manufactured metal components.« less

Effect of Powder-Suspended Dielectric on the EDM Characteristics of Inconel 625

NASA Astrophysics Data System (ADS)

Talla, Gangadharudu; Gangopadhyay, S.; Biswas, C. K.

2016-02-01

The current work attempts to establish the criteria for powder material selection by investigating the influence of various powder-suspended dielectrics and machining parameters on various EDM characteristics of Inconel 625 (a nickel-based super alloy) which is nowadays regularly used in aerospace, chemical, and marine industries. The powders include aluminum (Al), graphite, and silicon (Si) that have significant variation in their thermo-physical characteristics. Results showed that powder properties like electrical conductivity, thermal conductivity, density, and hardness play a significant role in changing the machining performance and the quality of the machined surface. Among the three powders, highest material removal rate was observed for graphite powder due to its high electrical and thermal conductivities. Best surface finish and least radial overcut (ROC) were attained using Si powder. Maximum microhardness was found for Si due to its low thermal conductivity and high hardness. It is followed by graphite and aluminum powders. Addition of powder to the dielectric has increased the crater diameter due to expansion of plasma channel. Powder-mixed EDM (PMEDM) was also effective in lowering the density of surface cracks with least number of cracks obtained with graphite powder. X-ray diffraction analysis indicated possible formation of metal carbides along with grain growth phenomenon of Inconel 625 after PMEDM.

Rapid identification of Bacillus anthracis spores in suspicious powder samples by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

PubMed

Dybwad, Marius; van der Laaken, Anton L; Blatny, Janet Martha; Paauw, Armand

2013-09-01

Rapid and reliable identification of Bacillus anthracis spores in suspicious powders is important to mitigate the safety risks and economic burdens associated with such incidents. The aim of this study was to develop and validate a rapid and reliable laboratory-based matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis method for identifying B. anthracis spores in suspicious powder samples. A reference library containing 22 different Bacillus sp. strains or hoax materials was constructed and coupled with a novel classification algorithm and standardized processing protocol for various powder samples. The method's limit of B. anthracis detection was determined to be 2.5 × 10(6) spores, equivalent to a 55-μg sample size of the crudest B. anthracis-containing powder discovered during the 2001 Amerithrax incidents. The end-to-end analysis method was able to successfully discriminate among samples containing B. anthracis spores, closely related Bacillus sp. spores, and commonly encountered hoax materials. No false-positive or -negative classifications of B. anthracis spores were observed, even when the analysis method was challenged with a wide range of other bacterial agents. The robustness of the method was demonstrated by analyzing samples (i) at an external facility using a different MALDI-TOF MS instrument, (ii) using an untrained operator, and (iii) using mixtures of Bacillus sp. spores and hoax materials. Taken together, the observed performance of the analysis method developed demonstrates its potential applicability as a rapid, specific, sensitive, robust, and cost-effective laboratory-based analysis tool for resolving incidents involving suspicious powders in less than 30 min.

Rapid Identification of Bacillus anthracis Spores in Suspicious Powder Samples by Using Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS)

PubMed Central

van der Laaken, Anton L.; Blatny, Janet Martha; Paauw, Armand

2013-01-01

Rapid and reliable identification of Bacillus anthracis spores in suspicious powders is important to mitigate the safety risks and economic burdens associated with such incidents. The aim of this study was to develop and validate a rapid and reliable laboratory-based matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) analysis method for identifying B. anthracis spores in suspicious powder samples. A reference library containing 22 different Bacillus sp. strains or hoax materials was constructed and coupled with a novel classification algorithm and standardized processing protocol for various powder samples. The method's limit of B. anthracis detection was determined to be 2.5 × 106 spores, equivalent to a 55-μg sample size of the crudest B. anthracis-containing powder discovered during the 2001 Amerithrax incidents. The end-to-end analysis method was able to successfully discriminate among samples containing B. anthracis spores, closely related Bacillus sp. spores, and commonly encountered hoax materials. No false-positive or -negative classifications of B. anthracis spores were observed, even when the analysis method was challenged with a wide range of other bacterial agents. The robustness of the method was demonstrated by analyzing samples (i) at an external facility using a different MALDI-TOF MS instrument, (ii) using an untrained operator, and (iii) using mixtures of Bacillus sp. spores and hoax materials. Taken together, the observed performance of the analysis method developed demonstrates its potential applicability as a rapid, specific, sensitive, robust, and cost-effective laboratory-based analysis tool for resolving incidents involving suspicious powders in less than 30 min. PMID:23811517

XAP, a program for deconvolution and analysis of complex X-ray spectra

USGS Publications Warehouse

Quick, James E.; Haleby, Abdul Malik

1989-01-01

The X-ray analysis program (XAP) is a spectral-deconvolution program written in BASIC and specifically designed to analyze complex spectra produced by energy-dispersive X-ray analytical systems (EDS). XAP compensates for spectrometer drift, utilizes digital filtering to remove background from spectra, and solves for element abundances by least-squares, multiple-regression analysis. Rather than base analyses on only a few channels, broad spectral regions of a sample are reconstructed from standard reference spectra. The effects of this approach are (1) elimination of tedious spectrometer adjustments, (2) removal of background independent of sample composition, and (3) automatic correction for peak overlaps. Although the program was written specifically to operate a KEVEX 7000 X-ray fluorescence analytical system, it could be adapted (with minor modifications) to analyze spectra produced by scanning electron microscopes, electron microprobes, and probes, and X-ray defractometer patterns obtained from whole-rock powders.

Characterisation of Sol-Gel Synthesis of Phase Pure CaTiO3 Nano Powders after Drying

NASA Astrophysics Data System (ADS)

Mallik, P. K.; Biswal, G.; Patnaik, S. C.; Senapati, S. K.

2015-02-01

According to a few recent studies, calcium titanate (CT) is a material that is similar to hydroxyapatite in biological properties. However, calcium titanate is not currently being used in the biomedical applications as to hydroxyapatite. The objective is to prepare nano calcium titanate powders from the equimolar solution of calcium oxide, ethanol and Titanium (IV) isopropoxide via sol-gel synthesis. The phase analysis and morphology of powder particles were studied by X-ray diffraction (XRD), while the composition and size of powder particles were determined by Transmission electron microscope (TEM) attached with energy dispersive x-ray spectrometer (EDS). As results, XRD confirm the presence of phase pure crystalline CaTiO3 after drying at 100°C for 24 hours, while TEM analysis confirms about 13 nm sizes of CaTiO3 particles and some agglomerated particle of 20-30 nm. Moreover, EDS analysis indicates that the approximately stoichiometric Ca/Ti ratio 1:1 was obtained in the CaTiO3 powders. Finally, it can be concluded that described sol-gel synthesis could be novel method for the production of nano CaTiO3 particles at lower temperature compared to any other methods of production.

Molecular Design and Synthesis of New Noncrystalline Solids

DTIC Science & Technology

1981-06-01

1. Powder X-ray diffraction pattern obtained have concluded that the crystallinity of the films using CuKa radiation. Sharp lines in is a sensitive ...pattern ;is formned in tile detector plane for each position of thle incident beam onl thre specimen. Thte diameter of the region giving thie...analyzer or over an aperture placed immediately in front of a scintillator-photomultiplier detector . This recording method is so inefficient that

Nonaqueous slip casting of high temperature ceramic superconductors using an investment casting technique

NASA Technical Reports Server (NTRS)

Hooker, Matthew W. (Inventor); Taylor, Theodore D. (Inventor); Wise, Stephanie A. (Inventor); Buckley, John D. (Inventor); Vasquez, Peter (Inventor); Buck, Gregory M. (Inventor); Hicks, Lana P. (Inventor)

1993-01-01

A process for slip casting ceramic articles that does not employ parting agents and affords the casting of complete, detailed, precision articles that do not possess parting lines is presented. This process is especially useful for high temperature superconductors and water-sensitive ceramics. A wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell mold of the calcium sulfate-bonded investment material. The shell mold is cooled to room temperature, and a ceramic slip, created by dispersing a ceramic powder in an organic liquid, is poured therein. After a ceramic shell of desired thickness or a solid article has set up in the shell mold, excess ceramic slip is poured out. The shell mold is misted with water and peeled away from the ceramic article, after which the ceramic is fired to provide a complete, detailed, precision, high temperature superconductive ceramic article without parting lines. The casting technique may take place in the presence of a magnetic field to orient the ceramic powders during the casting process.

Device for preparing combinatorial libraries in powder metallurgy.

PubMed

Yang, Shoufeng; Evans, Julian R G

2004-01-01

This paper describes a powder-metering, -mixing, and -dispensing mechanism that can be used as a method for producing large numbers of samples for metallurgical evaluation or electrical or mechanical testing from multicomponent metal and cermet powder systems. It is designed to make use of the same commercial powders that are used in powder metallurgy and, therefore, to produce samples that are faithful to the microstructure of finished products. The particle assemblies produced by the device could be consolidated by die pressing, isostatic pressing, laser sintering, or direct melting. The powder metering valve provides both on/off and flow rate control of dry powders in open capillaries using acoustic vibration. The valve is simple and involves no relative movement, avoiding seizure with fine powders. An orchestra of such valves can be arranged on a building platform to prepare multicomponent combinatorial libraries. As with many combinatorial devices, identification and evaluation of sources of mixing error as a function of sample size is mandatory. Such an analysis is presented.

Comparison of the tribological properties of fluorinated cokes and graphites

NASA Technical Reports Server (NTRS)

Fusaro, Robert L.

1988-01-01

The friction, wear, endurance life, and surface morphology of rubbed (burnished) fluorinated graphite and fluorinated coke materials were studied. Two different coke powders, a graphitic carbon powder, and a graphite powder were fluorinated and then tribologically investigated. In addition, one of the coke powders was reduced in size before fluorinating to evaluate the effect of a finer particle size on the tribological properties. For comparison, graphite and coke powders which were not fluorinated were also tribologically evaluated. Elemental analysis by emission spectroscopy was performed on each sample to determine the impurity content and X-ray diffraction analysis was performed to determine the crystallinity. Coke was found to have very little lubricating ability, but fluorinated coke did possess good lubricating properties. However, the fluorinated graphite and fluorinated graphitic carbon (which gave equivalent results) gave superior results to those obtained with the fluorinated cokes. No tribological benefit was found for using small versus a larger particle size of coke, at least when evaluated as a rubbed film.

Comparison of the tribological properties of fluorinated cokes and graphites

NASA Technical Reports Server (NTRS)

Fusaro, Robert L.

1987-01-01

The friction, wear, endurance life, and surface morphology of rubbed (burnished) fluorinated graphite and fluorinated coke materials were studied. Two different coke powders, a graphitic carbon powder, and a graphite powder were fluorinated and then tribologically investigated. In addition, one of the coke powders was reduced in size before fluorinating to evaluate the effect of a finer particle size on the tribological properties. For comparison, graphite and coke powders which were not fluorinated were also tribologically evaluated. Elemental analysis by emission spectroscopy was performed on each sample to determine the impurity content and X-ray diffraction analysis was performed to determine the crystallinity. Coke was found to have very little lubricating ability, but fluorinated coke did possess good lubricating properties. However, the fluorinated graphite and fluorinated graphitic carbon (which gave equivalent results) gave superior results to those obtained with the fluorinated cokes. No tribological benefit was found for using small versus a larger particle size of coke, at least when evaluated as a rubbed film.

Environmental impacts of milk powder and butter manufactured in the Republic of Ireland.

PubMed

Finnegan, William; Goggins, Jamie; Clifford, Eoghan; Zhan, Xinmin

2017-02-01

The abolition of the milk quota system that was in place in Europe was abolished in 2015, which instigated an immediate increase in milk production in many European countries. This increase will aid in addressing the world's ever growing demand for food, but will incur increased stresses on the environmental impact and sustainability of the dairy industry. In this study, an environmental life cycle assessment was performed in order to estimate the environmental impacts associated with the manufacture of milk powder and butter in the Republic of Ireland. A farm gate to processing factory gate analysis, which includes raw milk transportation, processing into each product and packaging, is assessed in this study. Operational data was obtained from 5 dairy processing factories that produce milk powder (4 of which also produce butter). Results for each environmental impact category are presented per kilogram of product. Energy consumption (raw milk transportation and on-site electrical and thermal energy usage) contributes, on average, 89% and 78% of the total global warming potential, for milk powder and butter respectively, for the life cycle stages assessed. Similarly, energy consumption contributes, on average, 86% and 96% of the total terrestrial acidification potential for milk powder and butter respectively, for these life cycle stages. Emissions associated with wastewater treatment contribute approximately 10% and 40% to the total freshwater eutrophication potential and marine eutrophication potential, respectively, for both milk powder and butter production. In addition, packaging materials also has a significant contribution to these environmental impact categories for butter production. Results were also presented for three milk powder products being manufactured by the factories surveyed: skim milk powder, whole milk powder and full fat milk powder. The analysis presented in this paper helps to identify opportunities to reduce the environmental impacts associated with post-farm processing of milk powder and butter. Copyright © 2016 Elsevier B.V. All rights reserved.

Three-Arm Randomized Phase III Trial: Quality Aloe and Placebo Cream Versus Powder as Skin Treatment During Breast Cancer Radiation Therapy.

PubMed

Hoopfer, Donna; Holloway, Caroline; Gabos, Zsolt; Alidrisi, Maha; Chafe, Susan; Krause, Barbara; Lees, Alan; Mehta, Nirmal; Tankel, Keith; Strickland, Faith; Hanson, John; King, Charlotte; Ghosh, Sunita; Severin, Diane

2015-06-01

The efficacy of aloe extract in reducing radiation-induced skin injury is controversial. The purpose of the present 3-arm randomized trial was to test the efficacy of quality-tested aloe extract in reducing the severity of radiation-induced skin injury and, secondarily, to examine the effect of a moist cream versus a dry powder skin care regimen. A total of 248 patients with breast cancer were randomized to powder, aloe cream, or placebo cream. Acute skin toxicity was scored weekly and after treatment at weeks 1, 2, and 4 using a modified 10-point Catterall scale. The patients scored their symptom severity using a 6-point Likert scale and kept an acute phase diary. The aloe formulation did not reduce acute skin toxicity or symptom severity. Patients with a greater body mass index were more likely to develop acute skin toxicity. A similar pattern of increased skin reaction toxicity occurred with both study creams compared with the dry powder regimen. No evidence was found to support prophylactic application of quality aloe extract or cream to improve the symptoms or reduce the skin reaction severity. Our results support a dry skin care regimen of powder during radiation therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Thermal decomposition behavior of nano/micro bimodal feedstock with different solids loading

NASA Astrophysics Data System (ADS)

Oh, Joo Won; Lee, Won Sik; Park, Seong Jin

2018-01-01

Debinding is one of the most critical processes for powder injection molding. The parts in debinding process are vulnerable to defect formation, and long processing time of debinding decreases production rate of whole process. In order to determine the optimal condition for debinding process, decomposition behavior of feedstock should be understood. Since nano powder affects the decomposition behavior of feedstock, nano powder effect needs to be investigated for nano/micro bimodal feedstock. In this research, nano powder effect on decomposition behavior of nano/micro bimodal feedstock has been studied. Bimodal powders were fabricated with different ratios of nano powder, and the critical solids loading of each powder was measured by torque rheometer. Three different feedstocks were fabricated for each powder depending on solids loading condition. Thermogravimetric analysis (TGA) experiment was carried out to analyze the thermal decomposition behavior of the feedstocks, and decomposition activation energy was calculated. The result indicated nano powder showed limited effect on feedstocks in lower solids loading condition than optimal range. Whereas, it highly influenced the decomposition behavior in optimal solids loading condition by causing polymer chain scission with high viscosity.

The analysis of carbohydrates in milk powder by a new "heart-cutting" two-dimensional liquid chromatography method.

PubMed

Ma, Jing; Hou, Xiaofang; Zhang, Bing; Wang, Yunan; He, Langchong

2014-03-01

In this study, a new"heart-cutting" two-dimensional liquid chromatography method for the simultaneous determination of carbohydrate contents in milk powder was presented. In this two dimensional liquid chromatography system, a Venusil XBP-C4 analysis column was used in the first dimension ((1)D) as a pre-separation column, a ZORBAX carbohydrates analysis column was used in the second dimension ((2)D) as a final-analysis column. The whole process was completed in less than 35min without a particular sample preparation procedure. The capability of the new two dimensional HPLC method was demonstrated in the determination of carbohydrates in various brands of milk powder samples. A conventional one dimensional chromatography method was also proposed. The two proposed methods were both validated in terms of linearity, limits of detection, accuracy and precision. The comparison between the results obtained with the two methods showed that the new and completely automated two dimensional liquid chromatography method is more suitable for milk powder sample because of its online cleanup effect involved. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Polymer Infiltration Studies

NASA Technical Reports Server (NTRS)

Marchello, Joseph M.

1993-01-01

Significant progress has been made on the preparation of carbon fiber composites using advanced polymer resins during the past three months. Current and ongoing research activities reported herein include: (1) Prepregger Hot Sled Operation; (2) Ribbonizing Powder-Impregnated Towpreg; (3) Textile Composites from Powder-Coated Towpreg: Role of Bulk Factor; and (4) Powder Curtain Prepreg Process. During the coming months research will be directed toward further development of the new powder curtain prepregging method and on ways to customize dry powder towpreg for textile and robotic applications in aircraft part fabrication. Studies of multi-tow powder prepregging and ribbon preparation will be conducted in conjunction with continued development of prepegging technology and the various aspects of composite part fabrication using customized towpreg. Also, work will continue on the analysis of the new solution prepegger.

Damping behavior of polymer composites with high volume fraction of NiMnGa powders

NASA Astrophysics Data System (ADS)

Sun, Xiaogang; Song, Jie; Jiang, Hong; Zhang, Xiaoning; Xie, Chaoying

2011-03-01

Polymer composites inserted with high volume fraction (up to 70 Vol%) of NiMnGa powders were fabricated and their damping behavior was investigated by dynamic mechanical analysis. It is found that the polymer matrix has little influence on the transformation temperatures of NiMnGa powders. A damping peak appears for NiMnGa/epoxy resin (EP) composites accompanying with the martensitic transformation or reverse martensitic transformation of NiMnGa powders during cooling or heating. The damping capacity for NiMnGa/EP composites increases linearly with the increase of volume fraction of NiMnGa powders and, decreases dramatically as the test frequency increases. The fracture strain of NiMnGa/EP composites decrease with the increase of NiMnGa powders.

[Microscopic study of powders of hallucinogenic mushrooms--Psilocybe sp].

PubMed

Schäfer, A T

2000-01-01

The paper presents simple methods for microscopic examination and basic microchemical testing for the identification of suspect mushroom powders. The microscopic features of the most commonly cultivated and trafficked hallucinogenic genus Psilocybin are described and may serve for the decision whether any suspect material consists of such mushroom powder (and is therefore to be subjected to further analysis) or not.

Effects of Process Parameters and Cryotreated Electrode on the Radial Overcut of Aisi 304 IN SiC Powder Mixed Edm

NASA Astrophysics Data System (ADS)

Bhaumik, Munmun; Maity, Kalipada

Powder mixed electro discharge machining (PMEDM) is further advancement of conventional electro discharge machining (EDM) where the powder particles are suspended in the dielectric medium to enhance the machining rate as well as surface finish. Cryogenic treatment is introduced in this process for improving the tool life and cutting tool properties. In the present investigation, the characterization of the cryotreated tempered electrode was performed. An attempt has been made to study the effect of cryotreated double tempered electrode on the radial overcut (ROC) when SiC powder is mixed in the kerosene dielectric during electro discharge machining of AISI 304. The process performance has been evaluated by means of ROC when peak current, pulse on time, gap voltage, duty cycle and powder concentration are considered as process parameters and machining is performed by using tungsten carbide electrodes (untreated and double tempered electrodes). A regression analysis was performed to correlate the data between the response and the process parameters. Microstructural analysis was carried out on the machined surfaces. Least radial overcut was observed for conventional EDM as compared to powder mixed EDM. Cryotreated double tempered electrode significantly reduced the radial overcut than untreated electrode.

Understanding and management of female pattern alopecia.

PubMed

Leavitt, Matt

2008-11-01

Female pattern hair loss is devastating to many of the 21 million U.S. women who suffer from it. It is essential to differentiate female pattern hair loss from other types of hair loss to ensure appropriate treatment. Through use of follicular units, follicular families, and follicular pairing between existing hair follicles, natural-looking results can be achieved in women. Hair transplants create the benefit of increasing density and providing options for hair styling and can be combined with medications, devices, and styling aids such as minoxidil, low-level laser therapy, and topical powder makeup, respectively.

New Insights on the Recrystallization and New Growth of Extensively Radiation-damaged Zircon

NASA Astrophysics Data System (ADS)

Hanchar, J. M.; Schmitz, M. D.; Wirth, R.

2012-12-01

Approximately 10 grams of cm-sized nearly metamict zircon crystals from the Saranac Prospect in the Bancroft District of Ontario were combined by breaking into small pieces and then ground under ethanol to a fine powder with an agate mortar and pestle in order to make enough homogeneously mixed material for multiple powder X-Ray and diffraction scans, high-resolution transmission electron microscopy (HR-TEM) measurements, and chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-TIMS). While these large zircon crystals ground to a powder have a larger surface area and not in the same physical state (i.e., brown and metamict) as what is typically analyzed in single zircon CA-ID-TIMS U-Pb analysis (clear euhedral grains), the physical and chemical changes that occur during the heat treatment used in CA-TIMS are thought to be similar processes. Aliquots of the ground zircon powder were annealed in situ using a Pt furnace in a powder diffractometer during which time simultaneous powder diffraction patterns were acquired starting at 25°C, at elevated temperature (from 500°C to 1400°C) at selected time intervals, and then again at 25°C. The powder X-ray diffraction results indicate that below ~900°C the recrystallization of the zircon powder commences but is incomplete, even after 36 hours, with diffuse low intensity diffraction peaks. At 1150°C the zircon powder shows significant recrystallization. At 1150°C, the recrystallization is essentially complete in less than one hour. Before heating the zircon powder samples consisted of clear, transparent to brown, translucent, complexly zoned fragments. After heating at 900°C the zircon powder retained a smaller percentage of clear or brown complexly zoned fragments, while the majority of material had transformed to oscillatory or irregularly zoned, dominantly white opaque microcrystalline fragments. The clear fragments were hypothesized to be preexisting original crystalline zircon, the brown complexly zoned fragments preexisting metamict zircon, and the white opaque fragment new recrystallized zircon and other oxides. At 1150°C all that remained after heating were dominantly white opaque fragments and extremely rare clear fragments. A variety of fragment types from unannealed, 900°C and 1150°C anneals were chemically abraded in concentrated hydrofluoric acid at 190°C for 12 hours. Upon treatment with chemical abrasion, all unannealed material, nearly all material from the 900°C anneal, and all white opaque microcrystalline material from the 1150°C anneal dissolved; only the rare residual clear, transparent fragments from the 1150°C anneal were robust to chemical abrasion at these conditions. Residual clear fragments yielded concordant U-Pb ID-TIMS dates of 1064 Ma (considering updated U decay constant ratio), confirming the hypothesis that low-U closed system domains are preserved through annealing up to 1150°C and can be extracted via chemical abrasion from even dominantly metamict zircon crystals. By contrast, newly formed crystallites resulting from metamict zircon breakdown during annealing appear to be quite soluble during chemical abrasion. Further experiments are underway to refine minimum threshold chemical abrasion conditions necessary to eliminate open-system domains in the Saranac zircon.

Microencapsulation of Natural Anthocyanin from Purple Rosella Calyces by Freeze Drying

NASA Astrophysics Data System (ADS)

Nafiunisa, A.; Aryanti, N.; Wardhani, D. H.; Kumoro, A. C.

2017-11-01

Anthocyanin extract in powder form will improve its use since the powder is easier to store and more applicable. Microencapsulation method is introduced as an efficient way for protecting pigment such as anthocyanin. This research was aimed to characterise anthocyanin encapsulated products prepared from purple Roselle calyces by freeze drying. The liquid anthocyanin extracts from ultrasound-assisted extraction were freeze-dried with and without the addition of 10% w/w maltodextrins as a carrier and coating agents. The quality attributes of the powders were characterised by their colour intensity, water content, and solubility. Analysis of encapsulated material was performed for the powder added by maltodextrin. The stability of the microencapsulated pigment in solution form was determined for 11 days. Total anthocyanin content was observed through pH differential method. The results of the colour intensity analysis confirm that the product with maltodextrin addition has more intense colour with L* value of 29.69 a* value of 54.29 and b* value of 8.39. The result with the addition of maltodextrin has less moisture content and more soluble in water. It is verified that better results were obtained for powder with maltodextrin addition. Anthocyanin in the powder form with maltodextrin addition exhibits higher stability even after 11 days. In conclusion, the microencapsulation of anthocyanin with maltodextrin as a carrier and coating agent presented a potential method to produce anthocyanin powder from purple Roselle.

Morphology and structural development of reduced anatase-TiO{sub 2} by pure Ti powder upon annealing and nitridation: Synthesis of TiO{sub x} and TiO{sub x}N{sub y} powders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolokang, A.S., E-mail: Sylvester.Bolokang@transnet.net; DST/CSIR National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, Pretoria 0001; Transnet Engineering, Product Development, Private Bag X 528, Kilnerpark 0127

2015-02-15

It is well known that nitriding of titanium is suitable for surface coating of biomaterials and in other applications such as anti-reflective coating, while oxygen-rich titanium oxynitride has been applied in thin film resistors and photocatalysis. Thus in this work anatase was reduced with pure titanium powder during annealing in argon. This was done to avoid any metallic contamination and unwanted residual metal doping. As a result, interesting and different types of particle morphology were synthesized when the pre-milled elemental anatase and titanium powders were mixed. The formation of metastable face centred cubic and monoclinic titanium monoxide was detected bymore » the X-ray diffraction technique. The phases were confirmed by energy dispersive X-ray spectroscopy analysis. Raman analysis revealed weak intensity peaks for samples annealed in argon as compared to those annealed under nitrogen. - Graphical abstract: Display Omitted - Highlights: • Reaction of TiO{sub 2} and Ti induced metastable FCC and monoclinic TiO{sub x}. • Compositions of mixed powder were prepared from the unmilled and pre-milled powders. • Nitridation of TiO{sub x} yielded TiO{sub x}N{sub y} phase. • Mixed morphology was observed on all three powder samples.« less

Thermal behaviour and microanalysis of coal subbituminus

NASA Astrophysics Data System (ADS)

Heriyanti; Prendika, W.; Ashyar, R.; Sutrisno

2018-04-01

Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) is used to study the thermal behaviour of sub-bituminous coal. The DSC experiment was performed in air atmosphere up to 125 °C at a heating rate of 25 °C min1. The DSC curve showed that the distinct transitional stages in the coal samples studied. Thermal heating temperature intervals, peak and dissociation energy of the coal samples were also determined. The XRD analysis was used to evaluate the diffraction pattern and crystal structure of the compounds in the coal sample at various temperatures (25-350 °C). The XRD analysis of various temperatures obtained compounds from the coal sample, dominated by quartz (SiO2) and corundum (Al2O3). The increase in temperature of the thermal treatment showed a better crystal formation.

Geochemistry of inorganic nitrogen in waters released from coal-bed natural gas production wells in the Powder River Basin, Wyoming

USGS Publications Warehouse

Smith, Richard L.; Repert, Deborah A.; Hart, Charles P.

2009-01-01

Water originating from coal-bed natural gas (CBNG) production wells typically contains ammonium and is often disposed via discharge to ephemeral channels. A study conducted in the Powder River Basin, Wyoming, documented downstream changes in CBNG water composition, emphasizing nitrogen-cycling processes and the fate of ammonium. Dissolved ammonium concentrations from 19 CBNG discharge points ranged from 95 to 527 μM. Within specific channels, ammonium concentrations decreased with transport distance, with subsequent increases in nitrite and nitrate concentrations. Removal efficiency, or uptake, of total dissolved inorganic nitrogen (DIN) varied between channel types. DIN uptake was greater in the gentle-sloped, vegetated channel as compared to the incised, steep, and sparsely vegetated channel and was highly correlated with diel patterns of incident light and dissolved oxygen concentration. In a larger main channel with multiple discharge inputs (n = 13), DIN concentrations were >300 μM, with pH > 8.5, after 5 km of transport. Ammonium represented 25−30% of the large-channel DIN, and ammonium concentrations remained relatively constant with time, with only a weak diel pattern evident. In July 2003, the average daily large-channel DIN load was 23 kg N day−1entering the Powder River, an amount which substantially increased the total Powder River DIN load after the channel confluence. These results suggest that CBNG discharge may be an important source of DIN to western watersheds, at least at certain times of the year, and that net oxidation and/or removal is dependent upon the extent of contact with sediment and biomass, type of drainage channel, and time of day.

Spark plasma sintering of highly dense fine-grained mineral aggregates

NASA Astrophysics Data System (ADS)

Koizumi, S.; Suzuki, T. S.; Sakka, Y.; Hiraga, T.

2017-12-01

To obtain highly dense and fine-grained mineral aggregates, which are suitable for laboratory measurements of their physical and chemical properties, we applied spark plasma sintering (SPS) to synthetic mineral powders and powders originated from naturally derived crystals. SPS is an emerging consolidation technique which has been applied to various metals and ceramics and rarely to geomaterials (e.g., Guignard et al., 2011). The technique uses spark plasma created by a pulse direct current during heat treatment of powders in a graphite die. It has been found that the technique provides better densification with little grain growth during sintering compared to a conventional sintering technique in many materials. To obtain ideal highly dense fine-grained materials, it is essential to prepare starting powders suitable for the sintering and also to find appropriate sintering conditions of applied uniaxial pressures, pulsed current patterns and heating rates. We prepared synthetic mineral powers through solid state reaction of source powders at high temperature well developed by our group (Koizumi et al. 2010). We also used jet milling at wet condition and subsequent elutriation to prepare olivine powders with sub-micron particle size and equiaxed particle shape. At heating rate of ≦10°C/min and an achievement of highest temperature of 1150°C, Fe-free olivine aggregate with average grain size of 200 nm with porosity of 0.003% was obtained. We also could obtain olivine aggregate, which was sintered from powders of Horoman peridotite, with average grain size of 500 nm and porosity of 0.2%. We will show results of other minerals including major rock forming minerals of the Earth's crust.

Evaluation of dairy powder products implicates thermophilic sporeformers as the primary organisms of interest.

PubMed

Watterson, M J; Kent, D J; Boor, K J; Wiedmann, M; Martin, N H

2014-01-01

Dairy powder products (e.g., sweet whey, nonfat dry milk, acid whey, and whey protein concentrate-80) are of economic interest to the dairy industry. According to the US Dairy Export Council, customers have set strict tolerances (<500 to <1,000/g) for thermophilic and mesophilic spores in dairy powders; therefore, understanding proliferation and survival of sporeforming organisms within dairy powder processing plants is necessary to control and reduce sporeformer counts. Raw, work-in-process, and finished product samples were collected from 4 dairy powder processing facilities in the northeastern United States over a 1-yr period. Two separate spore treatments: (1) 80°C for 12min (to detect sporeformers) and (2) 100°C for 30min (to detect highly heat resistant sporeformers) were applied to samples before microbiological analyses. Raw material, work-in-process, and finished product samples were analyzed for thermophilic, mesophilic, and psychrotolerant sporeformers, with 77.5, 71.0, and 4.6% of samples being positive for those organisms, respectively. Work-in-process and finished product samples were also analyzed for highly heat resistant thermophilic and mesophilic sporeformers, with 63.7 and 42.6% of samples being positive, respectively. Sporeformer prevalence and counts varied considerably by product and plant; sweet whey and nonfat dry milk showed a higher prevalence of thermophilic and mesophilic sporeformers compared with acid whey and whey protein concentrate-80. Unlike previous reports, we found limited evidence for increased spore counts toward the end of processing runs. Our data provide important insight into spore contamination patterns associated with production of different types of dairy powders and support that thermophilic sporeformers are the primary organism of concern in dairy powders. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Development of Economical Improved Thick Film Solar Cell Contact

NASA Technical Reports Server (NTRS)

Ross, B.

1979-01-01

Materials were surveyed to provide candidates for an all metal electrode paste system. These consisted of a major constituent metal powder, a low melting metal powder suitable for a liquid phase sintering medium, and a powder material suitable as an etchant for silicon dioxide at sintering temperatures. By means of thermal gravimetric analysis a suitable binder was identified for low temperature fired inks.

An Inquiry-Based Project Focused on the X-Ray Powder Diffraction Analysis of Common Household Solids

ERIC Educational Resources Information Center

Hulien, Molly L.; Lekse, Jonathan W.; Rosmus, Kimberly A.; Devlin, Kasey P.; Glenn, Jennifer R.; Wisneski, Stephen D.; Wildfong, Peter; Lake, Charles H.; MacNeil, Joseph H.; Aitken, Jennifer A.

2015-01-01

While X-ray powder diffraction (XRPD) is a fundamental analytical technique used by solid-state laboratories across a breadth of disciplines, it is still underrepresented in most undergraduate curricula. In this work, we incorporate XRPD analysis into an inquiry-based project that requires students to identify the crystalline component(s) of…

Extract-filter-shoot liquid chromatography/mass spectrometry for analysis of vitamin D2 in a powdered supplement capsule and SRM 3280

USDA-ARS?s Scientific Manuscript database

An ‘extract-filter-shoot’ method for analysis of vitamin D2, ergocalciferol, in a dry powdered dietary supplement capsule containing rice flour excipient and in National Institute of Standards and Technology (NIST) standard reference material (SRM) 3280 is reported. Quantification of vitamin D2 was...

[Comparative analysis between origin of cooked traditional Chinese medicine powder and modern formula granules].

PubMed

Li, Rui; Zhai, Hua-Qiang; Tian, Wei-Lan; Hou, Ji-Ru; Jin, Shi-Yuan; Wang, Yong-Yan

2016-03-01

In this study, the origin and causes of cooked traditional Chinese medicine powder were reviewed, and a comprehensive analysis was made for the time background of modern traditional Chinese medicine formula granules and the future development trend, in order to provide reference for application and promotion of traditional Chinese medicine formula granules. By reference to ancient medical books of previous dynasties, a system review was conducted for infancy, formation, maturity and transition of cooked traditional Chinese medicine powder, and a comprehensive analysis was made for the six factors of cooked traditional Chinese medicine powder's maturity in the Song Dynasty. Efforts were made to collect domestic and foreign research literatures of modern formula granules, understand the detailed development, and conduct an objective analysis of the current clinical application of modern formula granules. According to the comparative analysis for the application characteristics of cooked traditional Chinese medicine powder and modern formula granules, ①the popularity of cooked traditional Chinese medicine powder in the Song Dynasty has six factors: soaring numbers of medical students and medical practitioners, high medical expenses due to huge army, rapid population growth, frequent epidemics and increasing diseases, and insufficient finances of central and local governments. ②On the basis of clinical application characteristics of traditional Chinese medicine formula granules, traditional Chinese medicine formula granules contain extracted and concentrated effective components, which guarantee the curative effect, meet modern people's demands for "quick, simple and convenience" traditional Chinese medicine decoctions, show a relatively high cost performance; however, formula granules are restricted by their varieties and lack unified quality control standards, and single-extract formula granules have not synergy and attenuation effects of combined traditional Chinese medicine decoctions, which also restricts its clinical application and promotion. ③Both have advantages in the process of clinical application, and shall be used based on syndromes. In conclusion, traditional Chinese medicine formula granules do not have disadvantages of "difficult, complicated, turbid and disorderly" cooked traditional Chinese medicine powder, and solve such problems as "inflexibility, expensiveness, restriction, disorder and inefficacy", which is the important basis for promoting traditional Chinese medicine formula granules. Copyright© by the Chinese Pharmaceutical Association.

Analysis of macromolecules, ligands and macromolecule-ligand complexes

DOEpatents

Von Dreele, Robert B [Los Alamos, NM

2008-12-23

A method for determining atomic level structures of macromolecule-ligand complexes through high-resolution powder diffraction analysis and a method for providing suitable microcrystalline powder for diffraction analysis are provided. In one embodiment, powder diffraction data is collected from samples of polycrystalline macromolecule and macromolecule-ligand complex and the refined structure of the macromolecule is used as an approximate model for a combined Rietveld and stereochemical restraint refinement of the macromolecule-ligand complex. A difference Fourier map is calculated and the ligand position and points of interaction between the atoms of the macromolecule and the atoms of the ligand can be deduced and visualized. A suitable polycrystalline sample of macromolecule-ligand complex can be produced by physically agitating a mixture of lyophilized macromolecule, ligand and a solvent.

A prospective clinical study in humans of an endosseous dental implant partially covered with a powder-sintered porous coating: 3- to 4-year results.

PubMed

Deporter, D A; Watson, P A; Pilliar, R M; Pharoah, M; Smith, D C; Chipman, M; Locker, D; Rydall, A

1996-01-01

A dental implant covered partially with a porous coating (EndoPore) developed at the University of Toronto was tested. This new implant is a tapered, truncated-cone endosseous root-form implant fabricated from Ti-6Al-4V. It utilizes a powder-sintered porous surface geometry over most of its length to promote three-dimensional bone ingrowth and implant stabilization. In this trial, three implants were placed in the anterior mandibles of 52 patients and were used subsequently as free-standing units to support an overdenture. Much shorter implants, shorter initial healing periods, and simpler surgical techniques than are customary with other implant designs were used. At the time of this report, all patients with implants had passed 3 years of function, and the cumulative implant success rate was 94.8%. Analysis of carefully standardized radiographs revealed a pattern of crestal bone loss similar to earlier published dog data. On a yearly basis, the mean bone loss was 0.43 mm in year 1, 0.17 mm in year 2, and 0.13 mm in year 3.

Moisture sorption by cellulose powders of varying crystallinity.

PubMed

Mihranyan, Albert; Llagostera, Assumpcio Piñas; Karmhag, Richard; Strømme, Maria; Ek, Ragnar

2004-01-28

Moisture in microcrystalline cellulose may cause stability problems for moisture sensitive drugs. The aim of this study was to investigate the influence of crystallinity and surface area on the uptake of moisture in cellulose powders. Powders of varying crystallinity were manufactured, and the uptake of moisture was investigated at different relative humidities. The structure of the cellulose powders was characterized by X-ray diffraction, BET surface area analysis, and scanning electron microscopy. Moisture uptake was directly related to the cellulose crystallinity and pore volume: Cellulose powders with higher crystallinity showed lower moisture uptake at relative humidities below 75%, while at higher humidities the moisture uptake could be associated with filling of the large pore volume of the cellulose powder of highest crystallinity. In conclusion, the structure of cellulose should be thoroughly considered when manufacturing low moisture grades of MCC.

Factors Influencing Ferrihydrite Crystallinity In Natural And Synthetic Systems

EPA Science Inventory

Recent investigations of the structure of the mineral ferrihydrite indicate that disparities in the number of peaks observed in powder x-ray diffraction patterns can be attributed to differences in crystallite size. This has lead to the conclusion that specimens previously refer...

Idealized powder diffraction patterns for cellulose polymorphs

USDA-ARS?s Scientific Manuscript database

Cellulose samples are routinely analyzed by X-ray diffraction to determine their crystal type (polymorph) and crystallinity. However, the connection is seldom made between those efforts and the crystal structures of cellulose that have been determined with synchrotron X-radiation and neutron diffrac...

Structural characterization, electrical conductivity and open circuit voltage studies of the nanocrystalline La10Si6O27 electrolyte material for SOFCs

NASA Astrophysics Data System (ADS)

Jena, Paramananda; Jayasubramaniyan, S.; Patro, P. K.; Lenka, R. K.; Sinha, Amit; Muralidharan, P.; Srinadhu, E. S.; Satyanarayana, N.

2018-02-01

Nanocrystalline La10Si6O27 apatite-type sample was synthesized by the co-precipitation method. Thermal behavior, phase, structure, morphology and elemental composition of La, O and Si of the synthesized La10Si6O27 sample were investigated through TG/DTA, XRD, FTIR, Raman spectroscopy and SEM-EDX measurements respectively. Formation of phase purity of the nanocrystalline La10Si6O27 sample was confirmed by analysing the measured X-ray powder diffraction (XRD) pattern using Rietveld refinement and the calculated average crystallite size of the La10Si6O27 sample was found to be 33 nm. The electrical conductivity of the sintered La10Si6O27 pellet was investigated as a function of temperature ranging from 200 to 800 °C under air and it was found to be 1.92 × 10-3 S cm-1 at 800 °C. The chemical stability of La10Si6O27 powder under oxidizing and reducing atmospheres was confirmed from the analysis of the measured XRD pattern and Raman spectral results. Open circuit potential of a button cell, made up of the La10Si6O27 sample, was tested up to 800 °C with both oxygen and hydrogen at opposite sides of the cell and was found to 1 V. Hence, the results demonstrate that La10Si6O27 could be a promising solid electrolyte material for the solid oxide fuel cell (SOFC) applications.

Allelopathic potential of Macaranga tanarius (L.) muell.-arg.

PubMed

Tseng, Mei-Huims; Kuo, Yueh-Hsiung; Chen, Yih-Ming; Chou, Chang-Hung

2003-05-01

Macaranga tanarius is widely distributed in the abandoned lowlands of Taiwan where substantial amounts of leaves accumulate on the ground. A unique pattern of weed exclusion underneath trees is often found and thought to result from allelopathic interactions. Density-dependent phytotoxicity analysis of Lactuca sativa L. (lettuce) growing in soil mixed with the powder of M. tanarius leaves showed a significant deviation from the expected yield-density relationship. Lettuce growth was most suppressed in the low seed density experiment suggesting that the phytotoxins produced during leaf decomposition inhibit the growth of lettuce seedlings. Bidens pilosa and Leucaena leucocephala, growing in soil mixed with the leaf powder of M. tanarius were also suppressed. Aqueous leaf extracts were bioassayed against lettuce and B. pilosa, and exhibited a significant suppression in radicle growth. Compounds identified from leaves included nymphaeol-A (1), nymphaeol-B (2), nymphaeol-C (3), quercetin (4), abscisic acid (ABA) (5), blumenol A (6), blumenol B (7), roseoside II (8), tanariflavanone A (9), and tanariflavanone B (10), ABA was the major growth inhibitor. At concentrations of 20 ppm, ABA suppressed lettuce germination, while at 120 ppm it inhibited the growth of Miscanthus floridulus, Chloris barbata, and Bidens pilosa. At 600 ppm, quercetin, blumenol A, and blumenol B, caused 20-25% inhibition of radicle and shoot growth of M. floridulus. The amount of ABA in M. tanarius leaves was approximately 3-5 microg g(-1) dry weight, significantly higher than previously reported. We conclude that the pattern of weed exclusion underneath stands of M. tanarius and its invasion into its adjacent grassland vegetation results from allelopathic interactions.

Synthesis, growth, structural, optical and thermal properties of an organic single crystal: 4-nitroaniline 4-aminobenzoic acid.

PubMed

Silambarasan, A; Rajesh, P; Ramasamy, P

2014-01-24

The organic single crystals of 4-nitroaniline 4-aminobenzoic acid (4NAABA) were grown from ethanol solvent. The lattice parameters of the grown crystal have been confirmed from single crystal XRD analysis. The powder XRD pattern shows the various planes of grown crystal. The FTIR and (1)H NMR spectral analysis confirm the presence of various functional groups and the placement of proton in 4NAABA compound respectively. The UV absorption was carried out which shows the cutoff wavelength around 459 nm. The optical band gap of the crystal has been evaluated from the transmission spectra and absorption coefficient by extrapolation technique. In addition, a fluorescence spectral analysis is carried out for 4NAABA crystals. The thermal properties of crystals were evaluated from thermogravimetrical analysis. It shows that the grown crystal is stable up to 160°C and the crystal has sharp melting point at 151°C. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis and characterization of nanocrystalline Al 2024-B4C composite powders by mechanical alloying

NASA Astrophysics Data System (ADS)

Varol, T.; Canakci, A.

2013-06-01

In the present work, the effect of milling parameters on the morphology and microstructure of nanostructure Al2024-B4C composite powders obtained by mechanical alloying (MA) was studied. The effects of milling time and B4C content on the morphology, microstructure and particle size of nanostructure Al2024-B4C composite powders have been investigated. Different amounts of B4C particles (0, 5, 10 and 20 wt.%) were mixed with Al2024 powders and milled in a planetary ball mill for 30, 60, 120, 300, 420 and 600 min. Al 2024-B4C composite powders were characterized using a scanning electron microscope (SEM), laser particle-size analyzer, X-ray diffraction analysis (XRD) and the Vickers microhardness test. The results showed that the nanostructure Al2024-B4C composite powders were produced when they were milled for 600 min. The size of composite powder in the milled powder mixture was affected by the milling time and content of B4C particles. Moreover, it was observed that when MA reached a steady state, the properties of composite powders were stabilized.

Effect of Fe-Mn addition on microstructure and magnetic properties of NdFeB magnetic powders

NASA Astrophysics Data System (ADS)

Kurniawan, C.; Purba, A. S.; Setiadi, E. A.; Simbolon, S.; Warman, A.; Sebayang, P.

2018-03-01

In this paper, the effect of Fe-Mn alloy addition on microstructures and magnetic properties of NdFeB magnetic powders was investigated. Varied Fe-Mn compositions of 1, 5, and 10 wt% were mixed with commercial NdFeB type MQA powders for 15 minutes using shaker mill. The characterizations were performed by powder density, PSA, XRD, SEM, and VSM. The Fe-Mn addition increased the powder density of NdFeB/Fe-Mn powders. On the other side, particle size distribution slightly decreased as the Fe-Mn composition increases. Magnetic properties of NdFeB/Fe-Mn powders changed with the increasing of Fe-Mn content. SEM analysis showed the particle size of NdFeB/Fe-Mn powder was smaller as the Fe-Mn composition increases. It showed that NdFeB/Fe-Mn particles have different size and shape for NdFeB and Fe-Mn particles separately. The optimum magnetic properties of NdFeB/Fe-Mn powder was achieved on the 5 wt% Fe-Mn composition with remanence M r = 49.45 emu/g, coercivity H c = 2.201 kOe, and energy product, BH max = 2.15 MGOe.

Electromagnetic and Microwave-Absorbing Properties of Plate-Like Nd-Ce-Fe Powder

NASA Astrophysics Data System (ADS)

Qiao, Ziqiang; Pan, Shunkang; Xiong, Jilei; Cheng, Lichun; Lin, Peihao; Luo, Jialiang

2017-01-01

Plate-like Ce x Nd2- x Fe17 ( x = 0.0, 0.1, 0.2, 0.3, 0.4) powders have been synthesized by an arc melting and high-energy ball milling method. The structure of the Nd-Ce-Fe powders was investigated by x-ray diffraction analysis. Their morphology and particle size distribution were evaluated by scanning electron microscopy and laser particle analysis. The saturation magnetization and electromagnetic parameters of the powders were characterized using vibrating-sample magnetometry and vector network analysis, respectively. The results reveal that the Ce x Nd2- x Fe17 ( x = 0.0, 0.1, 0.2, 0.3, 0.4) powders consisted of Nd2Fe17 single phase with different Ce contents. The particle size and saturation magnetization decreased with increasing Ce content. The resonant frequencies of ɛ″ and μ″ moved towards lower frequency with increasing Ce concentration. The minimum reflection loss value decreased as the Ce content was increased. The minimum reflection loss and absorption peak frequency of Ce0.2Nd1.8Fe17 with coating thickness of 1.8 mm were -22.5 dB and 7 GHz, respectively. Increasing the values of the complex permittivity and permeability could result in materials with good microwave absorption properties.

Roller compaction of different pseudopolymorphic forms of theophylline: Effect on compressibility and tablet properties.

PubMed

Hadzović, Ervina; Betz, Gabriele; Hadzidedić, Seherzada; El-Arini, Silvia Kocova; Leuenberger, Hans

2010-08-30

The effect of roller compaction on disintegration time, dissolution rate and compressibility of tablets prepared from theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate was studied. In addition, the influence of adding microcrystalline cellulose, a commonly used excipient, in mixtures with these materials was investigated. Theophylline anhydrate powder was used as a model drug to investigate the influence of different compaction pressures on the tablet properties. Tablets with same porosity were prepared by direct compaction and by roller compaction/re-compaction. Compressibility was characterized by Heckel and modified Heckel equations. Due to the property of polymorphic materials to change their form during milling and compression, X-ray diffraction analysis of theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate powders and granules was carried out. After roller compaction the disintegration time and the dissolution rate of the tablets were significantly improved. Compressibility of theophylline anhydrate powder and theophylline anhydrate fine powder was decreased, while theophylline monohydrate showed higher compressibility after roller compaction. Microcrystalline cellulose affected compressibility of theophylline anhydrate powder, theophylline anhydrate fine powder and theophylline monohydrate whereby the binary mixtures showed higher compressibility than the individual materials. X-ray diffraction analyses confirmed that there were no polymorphic/pseudopolymorphic changes after roller compaction. Copyright 2010 Elsevier B.V. All rights reserved.

Powder Bed Layer Characteristics: The Overseen First-Order Process Input

NASA Astrophysics Data System (ADS)

Mindt, H. W.; Megahed, M.; Lavery, N. P.; Holmes, M. A.; Brown, S. G. R.

2016-08-01

Powder Bed Additive Manufacturing offers unique advantages in terms of manufacturing cost, lot size, and product complexity compared to traditional processes such as casting, where a minimum lot size is mandatory to achieve economic competitiveness. Many studies—both experimental and numerical—are dedicated to the analysis of how process parameters such as heat source power, scan speed, and scan strategy affect the final material properties. Apart from the general urge to increase the build rate using thicker powder layers, the coating process and how the powder is distributed on the processing table has received very little attention to date. This paper focuses on the first step of every powder bed build process: Coating the process table. A numerical study is performed to investigate how powder is transferred from the source to the processing table. A solid coating blade is modeled to spread commercial Ti-6Al-4V powder. The resulting powder layer is analyzed statistically to determine the packing density and its variation across the processing table. The results are compared with literature reports using the so-called "rain" models. A parameter study is performed to identify the influence of process table displacement and wiper velocity on the powder distribution. The achieved packing density and how that affects subsequent heat source interaction with the powder bed is also investigated numerically.

Formulation and nutritional evaluation of a healthy vegetable soup powder supplemented with soy flour, mushroom, and moringa leaf.

PubMed

Farzana, Tasnim; Mohajan, Suman; Saha, Trissa; Hossain, Md Nur; Haque, Md Zahurul

2017-07-01

The research study was conducted to develop a healthy vegetables soup powder supplemented with soy flour, mushroom, moringa leaf and compare its nutritional facts with locally available soup powders. Proximate analysis and sensory evaluation were done by standard method. In this study, moisture, ash, protein, fat, fiber, carbohydrate, and energy content were ranged from 2.83% to 5.46%, 9.39% to 16.48%, 6.92% to 16.05%, 4.22% to 6.39%, 0.22% to 1.61%, 58.81% to 75.41%, and 337.42 to 386.72 kcal/100 g, respectively. Highest content of vitamin D, minerals, protein, and fiber and lowest content of moisture, fat, and carbohydrate were found in the presently developed soy-mushroom-moringa soup powder compare to locally available soup powders. Vitamin C was also found significantly higher than locally available soup powders S1, S2, and S3. Heavy metals were not found in any of the soup powders. On the sensory and microbiological point of view, the presently developed soup powder was found highly acceptable up to 6 months. So, the developed soy-mushroom-moringa soup powder is nutritionally superior to locally available soup powders and sufficient to meet day-to-day nutritional requirements as a supplement.

Quantitative analysis of packed and compacted granular systems by x-ray microtomography

NASA Astrophysics Data System (ADS)

Fu, Xiaowei; Milroy, Georgina E.; Dutt, Meenakshi; Bentham, A. Craig; Hancock, Bruno C.; Elliott, James A.

2005-04-01

The packing and compaction of powders are general processes in pharmaceutical, food, ceramic and powder metallurgy industries. Understanding how particles pack in a confined space and how powders behave during compaction is crucial for producing high quality products. This paper outlines a new technique, based on modern desktop X-ray tomography and image processing, to quantitatively investigate the packing of particles in the process of powder compaction and provide great insights on how powder densify during powder compaction, which relate in terms of materials properties and processing conditions to tablet manufacture by compaction. A variety of powder systems were considered, which include glass, sugar, NaCl, with a typical particle size of 200-300 mm and binary mixtures of NaCl-Glass Spheres. The results are new and have been validated by SEM observation and numerical simulations using discrete element methods (DEM). The research demonstrates that XMT technique has the potential in further investigating of pharmaceutical processing and even verifying other physical models on complex packing.

Analysis of Brazing Effect on Hot Corrosion Behavior of a Nickel-Based Aerospace Superalloy

NASA Astrophysics Data System (ADS)

Esmaeili, N.; Ojo, O. A.

2018-06-01

The effects of brazing and use of composite powder mixture as interlayer material on hot corrosion resistance of brazed IN738 superalloy were studied. Brazing was observed to result in significant reduction in the hot corrosion resistance of the superalloy. However, application of composite powder mixture, which consists of additive superalloy powder, enhanced the hot corrosion resistance of brazed samples. It is also found that although the use of composite powder mixture increased hot corrosion resistance of brazed alloy, if the additive powder completely melts, which is possible during brazing, it can significantly reduce the hot corrosion resistance of the brazed joint. Elemental micro-segregation during solidification of the joint with completely melted powder mixture produces chromium-depleted zones and consequently reduces hot corrosion resistance, since a uniform distribution and adequate chromium concentration are necessary to combat hot corrosion. This has not been previously reported in the literature and it is crucial to the use of composite powder mixture for enhancing the properties of brazed superalloys.

Polymer infiltration studies

NASA Technical Reports Server (NTRS)

Marchello, Joseph M.

1993-01-01

During the past three months, significant progress has been made on the preparation of carbon fiber composites using advanced polymer resins. The results are set forth in recent reports and publications, and will be presented at forthcoming national and international meetings. Current and ongoing research activities reported herein include: textile composites from powder-coated towpreg; role of surface coating in braiding; prepregger hot sled operation; ribbonizing powder-impregenated towpreg; textile composites from powder-coated towpreg; role of bulk factor powder curtain prepreg process advanced tow placement (ATP) open-section part warpage control. During the coming months research will be directed toward further development of the new powder curtain prepregging method and on ways to customize dry powder towpreg for textile and robotic applications in aircraft part fabrication. Studies of multi-tow powder prepregging and ribbon preparation will be conducted in conjunction with continued development of prepregging technology and the various aspects of composite part fabrication using customized towpreg. Also, during the period ahead work will continue on the analysis of the performance of the new solution prepregger.

[Theoretical modeling and experimental research on direct compaction characteristics of multi-component pharmaceutical powders based on the Kawakita equation].

PubMed

Si, Guo-Ning; Chen, Lan; Li, Bao-Guo

2014-04-01

Base on the Kawakita powder compression equation, a general theoretical model for predicting the compression characteristics of multi-components pharmaceutical powders with different mass ratios was developed. The uniaxial flat-face compression tests of powder lactose, starch and microcrystalline cellulose were carried out, separately. Therefore, the Kawakita equation parameters of the powder materials were obtained. The uniaxial flat-face compression tests of the powder mixtures of lactose, starch, microcrystalline cellulose and sodium stearyl fumarate with five mass ratios were conducted, through which, the correlation between mixture density and loading pressure and the Kawakita equation curves were obtained. Finally, the theoretical prediction values were compared with experimental results. The analysis showed that the errors in predicting mixture densities were less than 5.0% and the errors of Kawakita vertical coordinate were within 4.6%, which indicated that the theoretical model could be used to predict the direct compaction characteristics of multi-component pharmaceutical powders.

Electrochemical behaviors of wax-coated Li powder/Li 4Ti 5O 12 cells

NASA Astrophysics Data System (ADS)

Park, Han Eol; Seong, Il Won; Yoon, Woo Young

The wax-coated Li powder specimen was effectively synthesized using the drop emulsion technique (DET). The wax layer on the powder was verified by SEM, Focused Ion Beam (FIB), EDX and XPS. The porosity of a sintered wax-coated Li electrode was measured by linear sweep voltammetry (LSV) and compared with that of a bare, i.e., un-coated Li electrode. The electrochemical behavior of the wax-coated Li powder anode cell was examined by the impedance analysis and cyclic testing methods. The cyclic behavior of the wax-coated Li powder anode with the Li 4Ti 5O 12 (LTO) cathode cell was examined at a constant current density of 0.35 mA cm -2 with the cut-off voltages of 1.2-2.0 V at 25 °C. Over 90% of the initial capacity of the cell remained even after the 300th cycle. The wax-coated Li powder was confirmed to be a stable anode material.

Direct synthesis of zirconium powder by magnesium reduction

NASA Astrophysics Data System (ADS)

Lee, Dong-Won; Yun, Jung-Yeul; Yoon, Sung-Won; Wang, Jei-Pil

2013-05-01

The direct synthesis of zirconium powder has been conducted through an analysis of the chemical reaction between evaporated ZrCl4 and molten magnesium over a range of reduction temperatures, concentration of hydrochloric acid, and stirring time. The observed results indicated that the purity of zirconium powder increased with increased stirring time, and Mg and MgCl2 were removed by 10 wt% of hydrochloric acid solution. The pure zirconium powder was obtained by stirring again for 5 h using 5 wt% of hydrochloric acid solution. It was noted that the mean particle size increased when the reaction temperature was increased, and the size of the powder at 1,123 K and 1,173 K was found to be 10 μm and 15 μm, respectively. In addition, the purity of the powder was also improved with temperature, and its purity finally reached up to 99.5% at 1,250 K. Overall, pure zirconium powder was obtained after a stirring stage for 5 hours using 5 wt% of hydrochloric acid solution.

Extraction of Lithium from Brine Solution by Hydrolysis of Activated Aluminum Powder

NASA Astrophysics Data System (ADS)

Li, Yanhong; Chen, Xingyu; Liu, Xuheng; Zhao, Zhongwei; Liu, Chongwu

2018-05-01

Activated aluminum powder has been used to extract lithium from Mg-Li mixed solution via a hydrolysis-adsorption reaction. First, activated aluminum powder was prepared under the optimal conditions of NaCl addition of 70%, ball-milling time of 3 h, and ball-to-powder mass ratio of 20:1. Then, the activated aluminum powder was added into the Mg-Li mixed solution to extract lithium. X-ray diffraction analysis indicated that Li+ was adsorbed by freshly formed Al(OH)3 in the form of LADH-Cl [LiCl·2Al(OH)3·mH2O]. Under the optimal conditions of reaction time of 3 h, Al/Li molar ratio of 4:1 for activated aluminum powder addition, and reaction temperature of 70°C, lithium precipitation exceeded 90% while magnesium precipitation was controlled at 13%. These results indicate that activated aluminum powder can efficiently extract lithium from Mg-Li mixed solution via a hydrolysis-adsorption reaction.

Morphological and Crystalline Transitions in Monohydrous and Anhydrous Aripiprazole for a Long-Acting Injectable Suspension.

PubMed

Tan, Xinyi; Zhong, Yue; He, Luying; Zhang, Yuanyuan; Jing, Guanghui; Li, Song; Wang, Jing; He, Haibing; Tang, Xing

2017-05-01

Many formulation and manufacturing processes can lead to morphological and crystalline transitions in many polycrystalline drugs, changing the properties of active pharmaceutical ingredients (APIs) such as solubility and physical stability which influence their therapeutic effects and safety and so limit their usefulness. Here, we report significant changes in crystal forms and morphology, including the shape and size of particles during the manufacture of off-white aripiprazole (APZ) dry powders used for long-acting and injectable suspensions. With the optimal top-down approach, powders were prepared by recrystallizing uniform monohydrous APZ (MA) and polycrystalline anhydrous APZ (AA) form III, characterized by thermal analysis, PXRD, and FT-IR. However, powders involving MA (MAP) with a lower mean size (2.126 μm), narrower distribution (span = 1.90), and higher stability compared with AA dry powders (AAP) were found to exhibit dehydration behavior and morphological changes after completion of the preparation processes based on the results of thermal analysis. In the case of APZ powders, we wished to obtain more information to guide in the industrial production and experimental design of suspensions in the future.

FT-Raman and chemometric tools for rapid determination of quality parameters in milk powder: Classification of samples for the presence of lactose and fraud detection by addition of maltodextrin.

PubMed

Rodrigues Júnior, Paulo Henrique; de Sá Oliveira, Kamila; de Almeida, Carlos Eduardo Rocha; De Oliveira, Luiz Fernando Cappa; Stephani, Rodrigo; Pinto, Michele da Silva; de Carvalho, Antônio Fernandes; Perrone, Ítalo Tuler

2016-04-01

FT-Raman spectroscopy has been explored as a quick screening method to evaluate the presence of lactose and identify milk powder samples adulterated with maltodextrin (2.5-50% w/w). Raman measurements can easily differentiate samples of milk powder, without the need for sample preparation, while traditional quality control methods, including high performance liquid chromatography, are cumbersome and slow. FT-Raman spectra were obtained from samples of whole lactose and low-lactose milk powder, both without and with addition of maltodextrin. Differences were observed between the spectra involved in identifying samples with low lactose content, as well as adulterated samples. Exploratory data analysis using Raman spectroscopy and multivariate analysis was also developed to classify samples with PCA and PLS-DA. The PLS-DA models obtained allowed to correctly classify all samples. These results demonstrate the utility of FT-Raman spectroscopy in combination with chemometrics to infer about the quality of milk powder. Copyright © 2015 Elsevier Ltd. All rights reserved.

Combustion Synthesis of Sm0.5Sr0.5CoO3-x and La0.6Sr0.4CoO3-x Nanopowders for Solid Oxide Fuel Cell Cathodes

NASA Technical Reports Server (NTRS)

Bansal, Narottam P.; Zhong, zhimin

2005-01-01

Nanopowders of Sm0.5Sr0.5CoO(3-x) (SSC) and La0.6Sr0.4CoO(3-x) (LSC) compositions, which are being investigated as cathode materials for intermediate temperature solid oxide fuel cells, were synthesized by a solution-combustion method using metal nitrates and glycine as fuel. Development of crystalline phases in the as-synthesized powders after heat treatments at various temperatures was monitored by x-ray diffraction. Perovskite phase in LSC formed more readily than in SSC. Single phase perovskites were obtained after heat treatment of the combustion synthesized LSC and SSC powders at 1000 and 1200 C, respectively. The as-synthesized powders had an average particle size of 12 nm as determined from x-ray line broadening analysis using the Scherrer equation. Average grain size of the powders increased with increase in calcination temperature. Morphological analysis of the powders calcined at various temperatures was done by scanning electron microscopy.

Solid state characterization and crystal structure from X-ray powder diffraction of two polymorphic forms of ranitidine base.

PubMed

de Armas, Héctor Novoa; Peeters, Oswald M; Blaton, Norbert; Van Gyseghem, Elke; Martens, Johan; Van Haele, Gerrit; Van Den Mooter, Guy

2009-01-01

Ranitidine hydrochloride (RAN-HCl), a known anti-ulcer drug, is the product of reaction between HCl and ranitidine base (RAN-B). RAN-HCl has been extensively studied; however this is not the case of the RAN-B. The solid state characterization of RAN-B polymorphs has been carried out using different analytical techniques (microscopy, thermal analysis, Fourier transform infrared spectrometry in the attenuated total reflection mode, (13)C-CPMAS-NMR spectroscopy and X-ray powder diffraction). The crystal structures of RAN-B form I and form II have been determined using conventional X-ray powder diffraction in combination with simulated annealing and whole profile pattern matching, and refined using rigid-body Rietveld refinement. RAN-B form I is a monoclinic polymorph with cell parameters: a = 7.317(2), b = 9.021(2), c = 25.098(6) A, beta = 95.690(1) degrees and space group P2(1)/c. The form II is orthorhombic: a = 31.252(4), b = 13.052(2), c = 8.0892(11) A with space group Pbca. In RAN-B polymorphs, the nitro group is involved in a strong intramolecular hydrogen bond responsible for the existence of a Z configuration in the enamine portion of the molecules. A tail to tail packing motif can be denoted via intermolecular hydrogen bonds. The crystal structures of RAN-B forms are compared to those of RAN-HCl polymorphs. RAN-B polymorphs are monotropic polymorphic pairs. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

[Identification of antler powder components based on DNA barcoding technology].

PubMed

Jia, Jing; Shi, Lin-chun; Xu, Zhi-chao; Xin, Tian-yi; Song, Jing-yuan; Chen Shi, Lin

2015-10-01

In order to authenticate the components of antler powder in the market, DNA barcoding technology coupled with cloning method were used. Cytochrome c oxidase subunit I (COI) sequences were obtained according to the DNA barcoding standard operation procedure (SOP). For antler powder with possible mixed components, the cloning method was used to get each COI sequence. 65 COI sequences were successfully obtained from commercial antler powders via sequencing PCR products. The results indicates that only 38% of these samples were derived from Cervus nippon Temminck or Cervus elaphus Linnaeus which is recorded in the 2010 edition of "Chinese Pharmacopoeia", while 62% of them were derived from other species. Rangifer tarandus Linnaeus was the most frequent species among the adulterants. Further analysis showed that some samples collected from different regions, companies and prices, contained adulterants. Analysis of 36 COI sequences obtained by the cloning method showed that C. elaphus and C. nippon were main components. In addition, some samples were marked clearly as antler powder on the label, however, C. elaphus or R. tarandus were their main components. In summary, DNA barcoding can accurately and efficiently distinguish the exact content in the commercial antler powder, which provides a new technique to ensure clinical safety and improve quality control of Chinese traditional medicine

Understanding microstrain anisotropy in yttrium oxide synthesized by sol-gel route

NASA Astrophysics Data System (ADS)

Murugesan, S.; Thirumurugesan, R.; Parameswaran, P.

2018-04-01

Yttrium oxide was synthesized by wet chemical route and calcined at various temperatures. On x-ray diffraction analysis of the material using Williamson-Hall analysis followed by Rietveld analysis indicates that the powder exists in nano crystallite size with lattice strain. The spherical harmonics analysis model of microstrain indicates the presence of strain anisotropy. The change in crystal structure lattice parameter, atomic coordinates of Y, O in yttria and the bond length analysis of the calcined powder reveals the presence of oxygen vacancies in the system.

The crystal structure of calcite III

NASA Astrophysics Data System (ADS)

Smyth, Joseph R.; Ahrens, Thomas J.

The crystal structure of calcite III has been deduced from existing high pressure powder X-ray diffraction patterns, based on the assumption that it is a displacive modification of the calcite I structure. The structure is monoclinic with space group C2 and a Z of 6. There are two Ca and two C positions, and five O positions, and atom coordinates have been refined by distance-least-squares methods to give reasonable octahedral coordination for Ca and parallel, planar CO3 groups. Unit cell parameters refined from a published powder diffraction pattern at 4.1 GPa are: a = 8.746(8)Å b = 4.685(5)Å c = 8.275(8)Å and β= 94.4°. The structure has a calculated density of 2.949 Mg/m³ at 4.1 GPa which is less than that of aragonite at this pressure and consistent with early piston cylinder studies. This implies that calcite III is indeed a metastable intermediary between calcite I and aragonite.

Optical properties of hydroxyapatite obtained by mechanical alloying

NASA Astrophysics Data System (ADS)

Silva, C. C.; Thomazini, D.; Pinheiro, A. G.; Lanciotti, F.; Sasaki, J. M.; Góes, J. C.; Sombra, A. S. B.

2002-09-01

Calcium phosphate based bioceramics, mainly in the form of hydroxyapatite (HA), have been in use in medicine and dentistry for the last 20 years. Applications include coatings of orthopaedic and dental implants, alveolar ridge augmentation, maxillofacial surgery, otolaryngology, and scaffolds for bone growth and as powders in total hip and knee surgery. These materials exhibit several problems of handling and fabrication, which can be overcome by mixing with a suitable binder. In this paper, mechanical alloying has been used successfully to produce nanocrystalline powders of HA using five different experimental procedures. The milled HA were studied by X-ray powder diffraction, infrared and Raman scattering spectroscopy. For four different procedures, HA was obtained after a couple of hours of milling (on an average, 20 h of milling depending on the reaction procedure). The XRD patterns indicate that the grain size is within the range of 29-103 nm. This milling process, used to produce HA, presents the advantage that melting is not necessary and the powder obtained is nanocrystalline with extraordinary mechanical properties. The material can be compacted and transformed in solid ceramic samples. The high efficiency of the process opens a way to produce commercial amount of nanocrystalline HA. Due to the nanocrystalline character of this powder, their mechanical properties have changed and for this reason a pressure of 1 GPa is enough to shape the sample into any geometry.

Corrosion behavior of HVOF coated sheets

NASA Astrophysics Data System (ADS)

Yilbas, B. S.; Abdul-Aleem, B. J.; Khalid, M.

2003-12-01

High velocity oxygen-fuel (HVOF) thermal spray coating finds application in industry due to its superior resistance to corrosion and thermal loading. In the HVOF process, the metallic powders at elevated temperature are sprayed at supersonic speed onto a substrate material. The powder granules sprayed impact onto each other, forming a mechanical bonding across the coating layer. In most of the cases, the distances among the particles (powder granules sprayed) are not the same, which in turn results in inhomogeneous structure across the coating layer. Moreover, the rate of oxidation of the powder granules during the spraying process varies. Consequently, the electrochemical response of the coating layer surfaces next to the base material and free to atmosphere differs. In the current study, the electrochemical response of a coating sheet formed during HVOF thermal spraying was investigated. NiCrMoNb alloy (similar to Inconel 625) wass used for the powder granules. Thermal spraying was carried out onto a smooth surface of stainless steel workpiece (without grid blasting), and later the coating layer was removed from the surface to obtain the coating sheet for the electrochemical tests. It was found that the corrosion rate of the smooth surface (surface next to the stainless steel surface before its removal) is considerably larger than that corresponding to the rough surface (free surface) of the coating sheet, and no specific patterns were observed for the pit sites.

Transport Powder and Liquid Samples by Surface Acoustic Waves

NASA Technical Reports Server (NTRS)

Bao, Xiaoqi; Bar-Cohen, Yoseph; Sherrit, Stewart; Badescu, Mircea; Louyeh, Sahar

2009-01-01

Sample transport is an important requirement for In-situ analysis of samples in NASA planetary exploration missions. Tests have shown that powders or liquid drops on a surface can be transported by surface acoustic waves (SAW) that are generated on the surface using interdigital transducers. The phenomena were investigated experimentally and to generate SAWs interdigital electrodes were deposited on wafers of 128 deg rotated Y-cut LiNbO?. Transporting capability of the SAW device was tested using particles of various sizes and drops of various viscosities liquids. Because of different interaction mechanisms with the SAWs, the powders and the liquid drops were observed to move in opposite directions. In the preliminary tests, a speed of 180 mm/s was achieved for powder transportation. The detailed experimental setup and results are presented in this paper. The transporting mechanism can potentially be applied to miniaturize sample analysis system or " lab-on-chip" devices.

Thermal analysis, X-ray powder diffraction and electron microscopy data related with the production of 1:1 Caffeine:Glutaric Acid cocrystals.

PubMed

Duarte, Íris; Andrade, Rita; Pinto, João F; Temtem, Márcio

2016-09-01

The data presented in this article are related to the production of 1:1 Caffeine:Glutaric Acid cocrystals as part of the research article entitled "Green production of cocrystals using a new solvent-free approach by spray congealing" (Duarte et al., 2016) [1]. More specifically, here we present the thermal analysis and the X-ray powder diffraction data for pure Glutaric Acid, used as a raw material in [1]. We also include the X-ray powder diffraction and electron microscopy data obtained for the 1:1 Caffeine:Glutaric Acid cocrystal (form II) produced using the cooling crystallization method reported in "Operating Regions in Cooling Cocrystallization of Caffeine and Glutaric Acid in Acetonitrile" (Yu et al., 2010) [2]. Lastly, we show the X-ray powder diffraction data obtained for assessing the purity of the 1:1 Caffeine:Glutaric cocrystals produced in [1].

An improved soft-chemistry approach to the preparation of spinel powders

NASA Astrophysics Data System (ADS)

Cook, Ronald

2007-04-01

Spinel powders for the production of transparent polycrystalline ceramic windows have been produced using a number of traditional ceramic and sol-gel methods. We have demonstrated that magnesium aluminate spinel powders produced from the reaction of organo-magnesium compounds with surface modified boehmite precursors can be used to produce high quality transparent spinel parts. In previous work, the spinel powders were prepared by the reaction of surface-modified boehmite nanoparticles with magnesium acetylacetonate. While the magnesium acetylacetonate can produce small quantities of high quality spinel powders, it use for large scale production of spinel powders is problematic. Through a thermodynamic analysis we have identified a new high-purity, low-cost, low-toxicity organomagnesium compound that reacts the with surface modified boehmite nanoparticles to produce a spinel precursor. The magnesium doped precursor readily transforms into pure phase spinel at temperature between 900°C and 1200°C.

Comparative studies of industrial grade carbon black powders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chawla, Komal, E-mail: komalchawla.rs@gmail.com; Chauhan, Alok P. S., E-mail: chauhan.alok@gmail.com, E-mail: alok.chauhan@alumni.stonybrook.edu

Comparative studies of two dissimilar industrial grade Carbon Black (CB) powders (N375 and N405) were conducted. The structure, surface area and particle size are the three important characteristics of CB powder that determine their processability and application as filler in preparing rubber compounds. The powders were characterized for their structure using dibutyl phthalate absorption (DBPA), particle size via laser particle size analyzer and surface area by nitrogen adsorption method. The structural characterization showed that N405 had lower DBPA in comparison to N375, confirming low structure of N405 grade CB powder. It was observed from the particle size analysis that N375more » was coarser than N405 grade CB. The total surface area values were determined by the BET method based on the cross sectional area of the nitrogen molecule. N375, a coarse grade CB powder with high structure, depicted less surface area as compared to N405.« less

Modeling of magnetic particle orientation in magnetic powder injection molding

NASA Astrophysics Data System (ADS)

Doo Jung, Im; Kang, Tae Gon; Seul Shin, Da; Park, Seong Jin

2018-03-01

The magnetic micro powder orientation under viscous shear flow has been analytically understood and characterized into a new analytical orientation model for a powder injection molding process. The effects of hydrodynamic force from the viscous flow, external magnetic force and internal dipole-dipole interaction were considered to predict the orientation under given process conditions. Comparative studies with a finite element method proved the calculation validity with a partial differential form of the model. The angular motion, agglomeration and magnetic chain formation have been simulated, which shows that the effect of dipole-dipole interaction among powders on the orientation state becomes negligible at a high Mason number condition and at a low λ condition (the ratio of external magnetic field strength and internal magnetic moment of powder). Our developed model can be very usefully employed in the process analysis and design of magnetic powder injection molding.

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

PubMed

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

1999-09-01

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

Experiment Analysis and Modelling of Compaction Behaviour of Ag60Cu30Sn10 Mixed Metal Powders

NASA Astrophysics Data System (ADS)

Zhou, Mengcheng; Huang, Shangyu; Liu, Wei; Lei, Yu; Yan, Shiwei

2018-03-01

A novel process method combines powder compaction and sintering was employed to fabricate thin sheets of cadmium-free silver based filler metals, the compaction densification behaviour of Ag60Cu30Sn10 mixed metal powders was investigated experimentally. Based on the equivalent density method, the density-dependent Drucker-Prager Cap (DPC) model was introduced to model the powder compaction behaviour. Various experiment procedures were completed to determine the model parameters. The friction coefficients in lubricated and unlubricated die were experimentally determined. The determined material parameters were validated by experiments and numerical simulation of powder compaction process using a user subroutine (USDFLD) in ABAQUS/Standard. The good agreement between the simulated and experimental results indicates that the determined model parameters are able to describe the compaction behaviour of the multicomponent mixed metal powders, which can be further used for process optimization simulations.

Next Generation Thermal Barrier Coatings for the Gas Turbine Industry

NASA Astrophysics Data System (ADS)

Curry, Nicholas; Markocsan, Nicolaie; Li, Xin-Hai; Tricoire, Aurélien; Dorfman, Mitch

2011-01-01

The aim of this study is to develop the next generation of production ready air plasma sprayed thermal barrier coating with a low conductivity and long lifetime. A number of coating architectures were produced using commercially available plasma spray guns. Modifications were made to powder chemistry, including high purity powders, dysprosia stabilized zirconia powders, and powders containing porosity formers. Agglomerated & sintered and homogenized oven spheroidized powder morphologies were used to attain beneficial microstructures. Dual layer coatings were produced using the two powders. Laser flash technique was used to evaluate the thermal conductivity of the coating systems from room temperature to 1200 °C. Tests were performed on as-sprayed samples and samples were heat treated for 100 h at 1150 °C. Thermal conductivity results were correlated to the coating microstructure using image analysis of porosity and cracks. The results show the influence of beneficial porosity on reducing the thermal conductivity of the produced coatings.

Synthesis of the zeolitic imidazolate framework ZIF-4 from the ionic liquid 1-butyl-3-methylimidazolium imidazolate

NASA Astrophysics Data System (ADS)

Hovestadt, Maximilian; Schwegler, Johannes; Schulz, Peter S.; Hartmann, Martin

2018-05-01

A new synthesis route for the zeolitic imidazolate framework ZIF-4 using imidazolium imidazolate is reported. Additionally, the ionic liquid-derived material is compared to conventional ZIF-4 with respect to the powder X-ray diffraction pattern pattern, nitrogen uptake, particle size, and separation potential for olefin/paraffin gas mixtures. Higher synthesis yields were obtained, and the different particle size affected the performance in the separation of ethane and ethylene.

An improved approach to identify irradiated spices using electronic nose, FTIR, and EPR spectroscopy.

PubMed

Sanyal, Bhaskar; Ahn, Jae-Jun; Maeng, Jeong-Hwan; Kyung, Hyun-Kyu; Lim, Ha-Kyeong; Sharma, Arun; Kwon, Joong-Ho

2014-09-01

Changes in cumin and chili powder from India resulting from electron-beam irradiation were investigated using 3 analytical methods: electronic nose (E-nose), Fourier transform infrared (FTIR) spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy. The spices had been exposed to 6 to 14 kGy doses recommended for microbial decontamination. E-nose measured a clear difference in flavor patterns of the irradiated spices in comparison with the nonirradiated samples. Principal component analysis further showed a dose-dependent variation. FTIR spectra of the samples showed strong absorption bands at 3425, 3007 to 2854, and 1746 cm(-1). However, both nonirradiated and irradiated spice samples had comparable patterns without any noteworthy changes in functional groups. EPR spectroscopy of the irradiated samples showed a radiation-specific triplet signal at g = 2.006 with a hyper-fine coupling constant of 3 mT confirming the results obtained with the E-nose technique. Thus, E-nose was found to be a potential tool to identify irradiated spices. © 2014 Institute of Food Technologists®

Plasma Sprayed Hydroxyapatite Coatings: Influence of Spraying Power on Microstructure

NASA Astrophysics Data System (ADS)

Mohd, S. M.; Abd, M. Z.; Abd, A. N.

2010-03-01

The plasma sprayed hydroxyapatite (HA) coatings are used on metallic implants to enhance the bonding between the implant and bone in human body. The coating process was implemented at different spraying power for each spraying condition. The coatings formed from a rapid solidification of molten and partly molten particles that impact on the surface of substrate at high velocity and high temperature. The study was concentrated on different spraying power that is between 23 to 31 kW. The effect of different power on the coatings microstructure was investigated using scanning electron microscope (SEM) and phase composition was evaluated using X-ray diffraction (XRD) analysis. The coatings surface morphology showed distribution of molten, partially melted particles and some micro-cracks. The produced coatings were found to be porous as observed from the cross-sectional morphology. The coatings XRD results indicated the presence of crystalline phase of HA and each of the patterns was similar to the initial powder. Regardless of different spraying power, all the coatings were having similar XRD patterns.

Optimization of fruit punch using mixture design.

PubMed

Kumar, S Bharath; Ravi, R; Saraswathi, G

2010-01-01

A highly acceptable dehydrated fruit punch was developed with selected fruits, namely lemon, orange, and mango, using a mixture design and optimization technique. The fruit juices were freeze dried, powdered, and used in the reconstitution studies. Fruit punches were prepared according to the experimental design combinations (total 10) based on a mixture design and then subjected to sensory evaluation for acceptability. Response surfaces of sensory attributes were also generated as a function of fruit juices. Analysis of data revealed that the fruit punch prepared using 66% of mango, 33% of orange, and 1% of lemon had highly desirable sensory scores for color (6.00), body (5.92), sweetness (5.68), and pleasantness (5.94). The aroma pattern of individual as well as combinations of fruit juices were also analyzed by electronic nose. The electronic nose could discriminate the aroma patterns of individual as well as fruit juice combinations by mixture design. The results provide information on the sensory quality of best fruit punch formulations liked by the consumer panel based on lemon, orange, and mango.

Neutron diffraction study of the in situ oxidation of UO(2).

PubMed

Desgranges, Lionel; Baldinozzi, Gianguido; Rousseau, Gurvan; Nièpce, Jean-Claude; Calvarin, Gilbert

2009-08-17

This paper discusses uranium oxide crystal structure modifications that are observed during the low-temperature oxidation which transforms UO(2) into U(3)O(8). The symmetries and the structural parameters of UO(2), beta-U(4)O(9), beta-U(3)O(7), and U(3)O(8) were determined by refining neutron diffraction patterns on pure single-phase samples. Neutron diffraction patterns were also collected during the in situ oxidation of powder samples at 483 K. The lattice parameters and relative ratios of the four pure phases were measured during the progression of the isothermal oxidation. The transformation of UO(2) into U(3)O(8) involves a complex modification of the oxygen sublattice and the onset of complex superstructures for U(4)O(9) and U(3)O(7), associated with regular stacks of complex defects known as cuboctahedra, which consist of 13 oxygen atoms. The kinetics of the oxidation process are discussed on the basis of the results of the structural analysis.

Methodological aspects for metabolome visualization and characterization: a metabolomic evaluation of the 24 h evolution of human urine after cocoa powder consumption.

PubMed

Llorach-Asunción, R; Jauregui, O; Urpi-Sarda, M; Andres-Lacueva, C

2010-01-20

The LC-MS based metabolomics studies are characterized by the capacity to produce a large and complex dataset being mandatory to use the appropriate tools to recover and to interpret as maximum information as possible. In this context, a combined partial least square discriminat analysis (PLS-DA) and two-way hierarchical clustering (two-way HCA) using Bonferroni correction as filter is proposed to improve analysis in human urinary metabolome modifications in a nutritional intervention context. After overnight fasting, 10 subjects consumed cocoa powder with milk. Urine samples were collected before the ingestion product and at 0-6, 6-12, 12-24 h after test-meal consumption and analysed by LC-Q-ToF. The PLS-DA analysis showed a clear pattern related to the differences between before consumption period and the other three periods revealing relevant mass features in this separation, however, a weaker association between mass features and the three periods after cocoa consumption was observed. On the other hand, two-way HCA showed a separation of four urine time periods and point out the mass features associated with the corresponding urine times. The correlation matrix revealed complex relations between the mass features that could be used for metabolite identifications and to infer the possible metabolite origin. The reported results prove that combining visualization strategies would be an excellent way to produce new bioinformatic applications that help the scientific community to unravel the complex relations between the consumption of phytochemicals and their expected effects on health.

Development of modified release diltiazem HCl tablets using composite index to identify optimal formulation.

PubMed

Gohel, M C; Patel, M M; Amin, A F

2003-05-01

This article reports the preparation of tartaric acid treated ispaghula husk powder for the development of modified release tablets of diltiazem HCl by adopting direct compression technique and a 32 full factorial design. The modified ispaghula husk powder showed superior swelling and gelling as compared to untreated powder. Addition of compaction augmenting agent such as dicalcium phosphate was found to be essential for obtaining tablets with adequate crushing strength. In order to improve the crushing strength of diltiazem HCl tablets, to modulate drug release pattern, and to obtain similarity of dissolution profiles in distilled water and simulated gastric fluid (pH 1.2), modified guar gum was used along with modified ispaghula husk powder and tartaric acid. A novel composite index, which considers a positive or a negative deviation from an ideal value, was calculated considering percentage drug release in 60, 300, and 540 min as dependent variables for the selection of a most appropriate batch. Polynomial equation and contour plots are presented. The concept of similarity factor (f2) was used to prove similarity of dissolution in water and simulated gastric fluid (pH 1.2).

Occurrence and Characterization of Cronobacter spp. in Dehydrated Rice Powder from Chinese Supermarket

PubMed Central

Huang, Yan; Pang, Yiheng; Wang, Hong; Tang, Zhengzhu; Zhou, Yan; Zhang, Weiyu; Li, Xiugui; Tan, Dongmei; Li, Jian; Lin, Ying; Liu, Xiaoling; Huang, Weiyi; Shi, Yunliang

2015-01-01

Cronobacter spp. are emerging food-borne pathogens and have been identified as causative agents of meningitis and necrotizing enterocolitis in infants. Dehydrated rice is popular with a wide range of people and it is frequently used as a substitute for infant milk powder to baby older than four months. The occurrence of Cronobacter spp. was investigated in 1,012 samples of dehydrated rice powder collected from 14 manufacturers in China during 2010 to 2012. The isolates were identified using fusA allele sequencing and subtyped using pulsed-field gel electrophoresis. Seventy-six samples (7.5%) contained Cronobacter spp. The prevalence among manufacturers ranged from 0-28.8%. The 76 isolates included 4 species [Cronobacter sakazakii (52 isolates) Cronobacter malonaticus (14 isolates), Cronobacter dublinensis (7 isolates), and Cronobacter muytjensii (3 isolates)]. Twenty-three unique fusA alleles and sixty-six PFGE-patterns were detected. All isolated strains were observed to be sensitive or to show intermediate susceptibility to eight tested antimicrobial agents. The study revealed serious contamination of dehydrated rice powder by Cronobacter spp., with prevalence varying among manufacturers in China. Identified Cronobacter species, fusA alleles, and subtypes were diverse. PMID:26132635

A high-throughput platform for low-volume high-temperature/pressure sealed vessel solvent extractions.

PubMed

Damm, Markus; Kappe, C Oliver

2011-11-30

A high-throughput platform for performing parallel solvent extractions in sealed HPLC/GC vials inside a microwave reactor is described. The system consist of a strongly microwave-absorbing silicon carbide plate with 20 cylindrical wells of appropriate dimensions to be fitted with standard HPLC/GC autosampler vials serving as extraction vessels. Due to the possibility of heating up to four heating platforms simultaneously (80 vials), efficient parallel analytical-scale solvent extractions can be performed using volumes of 0.5-1.5 mL at a maximum temperature/pressure limit of 200°C/20 bar. Since the extraction and subsequent analysis by either gas chromatography or liquid chromatography coupled with mass detection (GC-MS or LC-MS) is performed directly from the autosampler vial, errors caused by sample transfer can be minimized. The platform was evaluated for the extraction and quantification of caffeine from commercial coffee powders assessing different solvent types, extraction temperatures and times. For example, 141±11 μg caffeine (5 mg coffee powder) were extracted during a single extraction cycle using methanol as extraction solvent, whereas only 90±11 were obtained performing the extraction in methylene chloride, applying the same reaction conditions (90°C, 10 min). In multiple extraction experiments a total of ~150 μg caffeine was extracted from 5 mg commercial coffee powder. In addition to the quantitative caffeine determination, a comparative qualitative analysis of the liquid phase coffee extracts and the headspace volatiles was performed, placing special emphasis on headspace analysis using solid-phase microextraction (SPME) techniques. The miniaturized parallel extraction technique introduced herein allows solvent extractions to be performed at significantly expanded temperature/pressure limits and shortened extraction times, using standard HPLC autosampler vials as reaction vessels. Remarkable differences regarding peak pattern and main peaks were observed when low-temperature extraction (60°C) and high-temperature extraction (160°C) are compared prior to headspace-SPME-GC-MS performed in the same HPLC/GC vials. Copyright © 2011 Elsevier B.V. All rights reserved.

Spray‐Dried Sodium Zirconate: A Rapid Absorption Powder for CO2 Capture with Enhanced Cyclic Stability

PubMed Central

Bamiduro, Faith; Ji, Guozhao; Brown, Andy P.; Dupont, Valerie A.

2017-01-01

Abstract Improved powders for capturing CO2 at high temperatures are required for H2 production using sorption‐enhanced steam reforming. Here, we examine the relationship between particle structure and carbonation rate for two types of Na2ZrO3 powders. Hollow spray‐dried microgranules with a wall thickness of 100–300 nm corresponding to the dimensions of the primary acetate‐derived particles gave about 75 wt % theoretical CO2 conversion after a process‐relevant 5 min exposure to 15 vol % CO2. A conventional powder prepared by solid‐state reaction carbonated more slowly, achieving only 50 % conversion owing to a greater proportion of the reaction requiring bulk diffusion through the densely agglomerated particles. The hollow granular structure of the spray‐dried powder was retained postcarbonation but chemical segregation resulted in islands of an amorphous Na‐rich phase (Na2CO3) within a crystalline ZrO2 particle matrix. Despite this phase separation, the reverse reaction to re‐form Na2ZrO3 could be achieved by heating each powder to 900 °C in N2 (no dwell time). This resulted in a very stable multicycle performance in 40 cycle tests using thermogravimetric analysis for both powders. Kinetic analysis of thermogravimetric data showed the carbonation process fits an Avrami–Erofeyev 2 D nucleation and nuclei growth model, consistent with microstructural evidence of a surface‐driven transformation. Thus, we demonstrate that spray drying is a viable processing route to enhance the carbon capture performance of Na2ZrO3 powder. PMID:28371521

Influence of thermal treatment on the formation of zirconia nanostructured powder by thermal decomposition of different precursors

NASA Astrophysics Data System (ADS)

Stoia, Marcela; Barvinschi, Paul; Barbu-Tudoran, Lucian; Negrea, Adina; Barvinschi, Floricica

2013-10-01

The paper presents some results concerning the preparation of zirconia powders starting from ZrOCl2·8H2O by using two synthesis methods: (a) precipitation with NH3, at 90 °C, and (b) thermal decomposition of carboxylate precursors, obtained in the reaction of zirconium nitrate and two different alcohols, 1,3-propanediol (PD) and poly(vinyl alcohol) (PVA), at 150 °C. The precursors obtained at different temperatures have been characterized by thermal analysis (TG, DTA) and FT-IR spectroscopy. DTA analysis evidenced very clearly the transition temperatures between zirconia crystalline phases. The precursors have been annealed at different temperatures in order to obtain zirconia powders and the as obtained powders have been characterized by means of X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). In case of precipitation method the presence of the tetragonal phase was observed at 400 °C, while the monoclinic phase appears at temperatures higher than 400 °C, becoming major crystalline phase starting with 700 °C. In case of the powders prepared by thermal decomposition of carboxylate precursors, the tetragonal phase was formed at temperatures below 700 °C, when the monoclinic phase begin to crystallize as secondary phase, in a higher proportion for the samples synthesized with 1,3-propanediol. All powders annealed at 1200 °C are pure monoclinic zirconia. SEM images have evidenced for the zirconia powders annealed at 1000 °C particles with diameters up to 150 nm, agglomerated in micrometer-sized aggregates, more individualized and homogenous than that obtained in the case of zirconia powder synthesized with poly(vinyl alcohol).

Synthesis and characterization of titanium dioxide (TiO2) nanopowder

NASA Astrophysics Data System (ADS)

Munirah, S.; Nadzirah, Sh.; Khusaimi, Z.; Fazlena, H.; Rusop, M.

2018-05-01

Titanium dioxide (TiO2) powder was synthesized via sol-gel technique using Titanium tetraisopropoxide (TTIP) and ethanol as precursors. Acetylacetone, distilled water, polyethylene glycol (PEG) and stabilizers (glacial acetic acid and nitric acid) were then added to the solution. The solution was left for ageing for 24 hours and then dried into powder. The synthesized powders were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA).

Antibacterial Property of Cold-Sprayed HA-Ag/PEEK Coating

NASA Astrophysics Data System (ADS)

Sanpo, Noppakun; Tan, Meng Lu; Cheang, Philip; Khor, K. A.

2009-03-01

The antibacterial behavior of HA-Ag (silver-doped hydroxyapatite) nanopowder and their composite coatings were investigated against Escherichia coli (DH5α). HA-Ag nanopowder and PEEK (poly-ether-ether-ketone)-based HA-Ag composite powders were synthesized using in-house powder processing techniques. Bacteria culture assay of HA-Ag nanopowder and their composite powders displayed excellent bacteriostatic activity against E. coli. The antibacterial activity increased with increasing concentration of HA-Ag nanoparticle in these composite powders. These nanocomposite powders were subsequently used as feedstock to generate antibacterial coatings via cold spray technology. The ratios of HA-Ag to PEEK in their composite powders were 80:20, 60:40, 40:60, and 20:80 (wt.%). Microstructural characterization and phase analysis of feedstock powders and as-deposited coatings were carried out using FESEM/EDX and XRD. Antibacterial nanocomposite HA-Ag/PEEK coatings were successfully deposited using cold spraying parameters of 11-12 bars at preheated air temperature between 150 and 160 °C. These as-sprayed coatings of HA-Ag/PEEK composite powders comprising varying HA-Ag and PEEK ratios retained their inherent antibacterial property as verified from bacterial assay. The results indicated that the antibacterial activity increased with increasing HA-Ag nanopowder concentration in the composite powder feedstock and cold-sprayed coating.

Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products

PubMed Central

2011-01-01

Background Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Results Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g)), total polyphenol content (TP (mg/g)), and total flavanol content (TF (mg/g)). Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Conclusions Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit". PMID:21299842

Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products.

PubMed

Crozier, Stephen J; Preston, Amy G; Hurst, Jeffrey W; Payne, Mark J; Mann, Julie; Hainly, Larry; Miller, Debra L

2011-02-07

Numerous popular media sources have developed lists of "Super Foods" and, more recently, "Super Fruits". Such distinctions often are based on the antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits. Cocoa powder and chocolate are made from an extract of the seeds of the fruit of the Theobroma cacao tree. In this study, we compared cocoa powder and cocoa products to powders and juices derived from fruits commonly considered "Super Fruits". Various fruit powders and retail fruit products were obtained and analyzed for antioxidant capacity (ORAC (μM TE/g)), total polyphenol content (TP (mg/g)), and total flavanol content (TF (mg/g)). Among the various powders that were tested, cocoa powder was the most concentrated source of ORAC and TF. Similarly, dark chocolate was a significantly more concentrated source of ORAC and TF than the fruit juices. Cocoa powder and dark chocolate had equivalent or significantly greater ORAC, TP, and TF values compared to the other fruit powders and juices tested, respectively. Cacao seeds thus provide nutritive value beyond that derived from their macronutrient composition and appear to meet the popular media's definition of a "Super Fruit".

Physical characterization of whole and skim dried milk powders.

PubMed

Pugliese, Alessandro; Cabassi, Giovanni; Chiavaro, Emma; Paciulli, Maria; Carini, Eleonora; Mucchetti, Germano

2017-10-01

The lack of updated knowledge about the physical properties of milk powders aimed us to evaluate selected physical properties (water activity, particle size, density, flowability, solubility and colour) of eleven skim and whole milk powders produced in Europe. These physical properties are crucial both for the management of milk powder during the final steps of the drying process, and for their use as food ingredients. In general, except for the values of water activity, the physical properties of skim and whole milk powders are very different. Particle sizes of the spray-dried skim milk powders, measured as volume and surface mean diameter were significantly lower than that of the whole milk powders, while the roller dried sample showed the largest particle size. For all the samples the size distribution was quite narrow, with a span value less than 2. The loose density of skim milk powders was significantly higher than whole milk powders (541.36 vs 449.75 kg/m 3 ). Flowability, measured by Hausner ratio and Carr's index indicators, ranged from passable to poor when evaluated according to pharmaceutical criteria. The insolubility index of the spray-dried skim and whole milk powders, measured as weight of the sediment (from 0.5 to 34.8 mg), allowed a good discrimination of the samples. Colour analysis underlined the relevant contribution of fat content and particle size, resulted in higher lightness ( L *) for skim milk powder than whole milk powder, which, on the other hand, showed higher yellowness ( b *) and lower greenness (- a *). In conclusion a detailed knowledge of functional properties of milk powders may allow the dairy to tailor the products to the user and help the food processor to perform a targeted choice according to the intended use.

The tungsten powder study of the dispenser cathode

NASA Astrophysics Data System (ADS)

Bao, Ji-xiu; Wan, Bao-fei

2006-06-01

The intercorrelation of tungsten powder properties, such as grain size, distribution and morphology, and porous matrix parameters with electron emission capability and longevity of Ba dispenser cathodes has been investigated for the different grain morphologies. It is shown that a fully cleaning step of the tungsten powder is so necessary that the tungsten powder will be reduction of oxide in hydrogen atmosphere above 700 °C. The porosity of the tungsten matrix distributes more even and the closed pore is fewer, the average granule size of the tungsten powder distributes more convergent. The porosity of the tungsten matrix and the evaporation of the activator are bigger and the pulse of the cathode is smaller when the granularity is bigger by the analysis of the electronic microscope and diode experiment.

Big Sky and Greenhorn Drill Holes and CheMin X-ray Diffraction

NASA Image and Video Library

2015-12-17

The graph at right presents information from the NASA Curiosity Mars rover's onboard analysis of rock powder drilled from the "Big Sky" and "Greenhorn" target locations, shown at left. X-ray diffraction analysis of the Greenhorn sample inside the rover's Chemistry and Mineralogy (CheMin) instrument revealed an abundance of silica in the form of noncrystalline opal. The broad hump in the background of the X-ray diffraction pattern for Greenhorn, compared to Big Sky, is diagnostic of opal. The image of Big Sky at upper left was taken by the rover's Mars Hand Lens Imager (MAHLI) camera the day the hole was drilled, Sept. 29, 2015, during the mission's 1,119th Martian day, or sol. The Greenhorn hole was drilled, and the MAHLI image at lower left was taken, on Oct. 18, 2015 (Sol 1137). http://photojournal.jpl.nasa.gov/catalog/PIA20272

Comparative study of glycine single crystals with additive of potassium nitrate in different concentration ratios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gujarati, Vivek P., E-mail: vivekgujarati@gmail.com; Deshpande, M. P., E-mail: vishwadeshpande@yahoo.co.in; Patel, Kamakshi R.

2016-05-06

Semi-organic crystals of Glycine Potassium Nitrate (GPN) with potential applications in Non linear optics (NLO) were grown using slow evaporation technique. Glycine and Potassium Nitrate were taken in three different concentration ratios of 3:1, 2:1 and 1:1 respectively. We checked the solubility of the material in distilled water at different temperatures and could observe the growth of crystals in 7 weeks time. Purity of the grown crystals was confirmed by Energy Dispersive X-ray Analysis (EDAX) and CHN analysis. GSN Powder X-ray diffraction pattern was recorded to confirm the crystalline nature. To confirm the applications of grown crystals in opto-electronics field,more » UV-Vis-NIR study was carried out. Dielectric properties of the samples were studied in between the frequency range 1Hz to 100 KHz.« less

Fungus mediated biosynthesis of WO3 nanoparticles using Fusarium solani extract

NASA Astrophysics Data System (ADS)

Kavitha, N. S.; Venkatesh, K. S.; Palani, N. S.; Ilangovan, R.

2017-05-01

Currently nanoparticles were synthesized by emphasis bioremediation process due to less hazardous, eco-friendly and imperative applications on biogenic process. Fungus mediated biosynthesis strategy has been developed to prepare tungsten oxide nanoflakes (WO3, NFs) using the plant pathogenic fungus F.solani. The powder XRD pattern revealed the monoclinic crystal structure with improved crystalline nature of the synthesized WO3 nanoparticles. FESEM images showed the flake-like morphology of WO3, with average thickness and length around 40 nm and 300 nm respectively. The Raman spectrum of WO3 NFs showed their characteristic vibration modes that revealed the defect free nature of the WO3 NFs. Further, the elemental analysis indicated the stoichiometric composition of WO3 phase.

Detection of N-(1-deoxy-D-fructos-1-yl) Fumonisins B₂ and B₃ in Corn by High-Resolution LC-Orbitrap MS.

PubMed

Matsuo, Yosuke; Takahara, Kentaro; Sago, Yuki; Kushiro, Masayo; Nagashima, Hitoshi; Nakagawa, Hiroyuki

2015-09-16

The existence of glucose conjugates of fumonisin B₂ (FB₂) and fumonisin B₃ (FB₃) in corn powder was confirmed for the first time. These "bound-fumonisins" (FB₂ and FB₃ bound to glucose) were identified as N-(1-deoxy-D-fructos-1-yl) fumonisin B₂ (NDfrc-FB₂) and N-(1-deoxy-D-fructos-1-yl) fumonisin B₃ (NDfrc-FB₃) respectively, based on the accurate mass measurements of characteristic ions and fragmentation patterns using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS) analysis. Treatment on NDfrc-FB₂ and NDfrc-FB₃ with the o-phthalaldehyde (OPA) reagent also supported that D-glucose binding to FB₂ and FB₃ molecules occurred to their primary amine residues.

Pt nanoparticle-reduced graphene oxide nanohybrid for proton exchange membrane fuel cells.

PubMed

Park, Dae-Hwan; Jeon, Yukwon; Ok, Jinhee; Park, Jooil; Yoon, Seong-Ho; Choy, Jin-Ho; Shul, Yong-Gun

2012-07-01

A platinum nanoparticle-reduced graphene oxide (Pt-RGO) nanohybrid for proton exchange membrane fuel cell (PEMFC) application was successfully prepared. The Pt nanoparticles (Pt NPs) were deposited onto chemically converted graphene nanosheets via ethylene glycol (EG) reduction. According to the powder X-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) analysis, the face-centered cubic Pt NPs (3-5 nm in diameter) were homogeneously dispersed on the RGO nanosheets. The electrochemically active surface area and PEMFC power density of the Pt-RGO nanohybrid were determined to be 33.26 m2/g and 480 mW/cm2 (maximum values), respectively, at 75 degrees C and at a relative humidity (RH) of 100% in a single-cell test experiment.

High-pressure polymorphism of the electrochemically active organic molecule tetrahydroxy-p-benzoquinone

DOE PAGES

Ciezak-Jenkins, Jennifer A.

2016-04-22

We have studied the structural and chemical response of tetrahydroxy-p-benzoquinone to isothermal compression to near 20 GPa using powder x-ray diffraction and vibrational spectroscopy. Compression beyond 11.5 GPa resulted in the appearance of several new peaks in the x-ray patterns, changes in the peak distribution and intensities, as well as the disappearance of features observed at lower pressures, which when coupled with concomitant changes in the infrared spectrum are indicative of a phase transition. Further analysis of the infrared spectra suggest this phase transition results in an increase in the anharmonicity of the system. Finally, Raman spectroscopic experiments indicate themore » high-pressure phase to be highly photosensitive and easily polymerized.« less

Selective Laser Melting of Metal Powder Of Steel 3161

NASA Astrophysics Data System (ADS)

Smelov, V. G.; Sotov, A. V.; Agapovichev, A. V.; Tomilina, T. M.

2016-08-01

In this article the results of experimental study of the structure and mechanical properties of materials obtained by selective laser melting (SLM), metal powder steel 316L was carried out. Before the process of cultivation of samples as the input control, the morphology of the surface of the powder particles was studied and particle size analysis was carried out. Also, 3D X-ray quality control of the grown samples was carried out in order to detect hidden defects, their qualitative and quantitative assessment. To determine the strength characteristics of the samples synthesized by the SLM method, static tensile tests were conducted. To determine the stress X-ray diffraction analysis was carried out in the material samples.

Detection of indoor biological hazards using the man-portable laser induced breakdown spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munson, Chase A.; Gottfried, Jennifer L.; Snyder, Emily Gibb

2008-11-01

The performance of a man-portable laser induced breakdown spectrometer was evaluated for the detection of biological powders on indoor office surfaces and wipe materials. Identification of pure unknown powders was performed by comparing against a library of spectra containing biological agent surrogates and confusant materials, such as dusts, diesel soot, natural and artificial sweeteners, and drink powders, using linear correlation analysis. Simple models constructed using a second technique, partial least squares discriminant analysis, successfully identified Bacillus subtilis (BG) spores on wipe materials and office surfaces. Furthermore, these models were able to identify BG on materials not used in the trainingmore » of the model.« less

Modification of semi-coke powder and its adsorption mechanisms for Cr(VI) and methylene blue

NASA Astrophysics Data System (ADS)

Zhang, Linjiang; Liu, Zhuannian; Fan, Yidan; Fan, Aping; Han, Xiaogang

2018-02-01

In this paper, the semi-coke powder was modified by three kinds of physical or chemical methods and then modified semi-coke was used as adsorbent for removal of Cr6+ and methylene blue (MB) from aqueous solution. The effects of time, dosage and pH on removal rate were investigated using batch experiments. The process of Cr6+ and MB adsorption onto the modified semi-coke powder follows pseudo second-order kinetics. The analysis of SEM and BET showed the Specific surface area of modified semi-coke are 84.92 m2/g, which is higher than that of raw semi-coke powder.

Synthesis of Cu-W nanocomposite by high-energy ball milling.

PubMed

Venugopal, T; Rao, K Prasad; Murty, B S

2007-07-01

The Cu-W bulk nanocomposites of different compositions were successfully synthesized by high-energy ball milling of elemental powders. The nanocrystalline nature of the Cu-W composite powder is confirmed by X-ray diffraction analysis, transmission electron microscopy, and atomic force microscopy. The Cu-W nanocomposite powder could be sintered at 300-400 degrees C below the sintering temperature of the un-milled Cu-W powders. The Cu-W nanocomposites showed superior densification and hardness than that of un-milled Cu-W composites. The nanocomposites also have three times higher hardness to resistivity ratio in comparison to Oxygen free high conductivity copper.

Heats of immersion of titania powders in primer solutions

NASA Technical Reports Server (NTRS)

Siriwardane, R.; Wightman, J. P.

1983-01-01

The oxide layer present on titanium alloys can play an important role in determining the strength and durability of adhesive bonds. Here, three titania powders in different crystalline phases, rutile-R1, anatase-A1, and anatase-A2, are characterized by several techniques. These include microelectrophoresis, X-ray diffractometry, surface area pore volume analysis, X-ray photoelectron spectroscopy, and measurements of the heats of immersion. Of the three powders, R1 has the highest heat of immersion in water, while the interaction between water and A1 powder is low. Experimental data also suggest a specific preferential interaction of polyphenylquinoxaline with anatase.

Trends in major-ion constituents and properties for selected sampling sites in the Tongue and Powder River watersheds, Montana and Wyoming, based on data collected during water years 1980-2010

USGS Publications Warehouse

Sando, Steven K.; Vecchia, Aldo V.; Barnhart, Elliott P.; Sando, Thomas R.; Clark, Melanie L.; Lorenz, David L.

2014-01-01

The primary purpose of this report is to present information relating to flow-adjusted temporal trends in major-ion constituents and properties for 16 sampling sites in the Tongue and Powder River watersheds based on data collected during 1980–2010. In association with this primary purpose, the report presents background information on major-ion characteristics (including specific conductance, calcium, magnesium, potassium, sodium adsorption ratio, sodium, alkalinity, chloride, fluoride, dissolved sulfate, and dissolved solids) of the sampling sites and coal-bed methane (CBM) produced water (groundwater pumped from coal seams) in the site watersheds, trend analysis methods, streamflow conditions, and factors that affect trend results. The Tongue and Powder River watersheds overlie the Powder River structural basin (PRB) in northeastern Wyoming and southeastern Montana. Limited extraction of coal-bed methane (CBM) from the PRB began in the early 1990’s, and increased dramatically during the late 1990’s and early 2000’s. CBM-extraction activities produce discharges of water with high concentrations of dissolved solids (particularly sodium and bicarbonate ions) relative to most stream water in the Tongue and Powder River watersheds. Water-quality of CBM produced water is of concern because of potential effects of sodium on agricultural soils and potential effects of bicarbonate on aquatic biota. Two parametric trend-analysis methods were used in this study: the time-series model (TSM) and ordinary least squares regression (OLS) on time, streamflow, and season. The TSM was used to analyze trends for 11 of the 16 study sites. For five sites, data requirements of the TSM were not met and OLS was used to analyze trends. Two primary 10-year trend-analysis periods were selected. Trend-analysis period 1 (water years 1986–95; hereinafter referred to as period 1) was selected to represent variability in major-ion concentrations in the Tongue and Powder River watersheds before potential effects of CBM-extraction activities. Trend analysis period 2 (water years 2001–10; hereinafter referred to as period 2) was selected because it encompassed substantial CBM-extraction activities and therefore might indicate potential effects of CBM-extraction activities on water quality of receiving streams in the Tongue and Powder River watersheds. For sites that did not satisfy data requirements for the TSM, OLS was used to analyze trends for period 2 (if complete data were available) or a 6-year period (2005–10). Flow-rate characteristics of CBM-produced water were estimated to allow general comparisons with streamflow characteristics of the sampling sites. The information on flow-rate characteristics of CBM-produced water in relation to streamflow does not account for effects of disposal, treatment, or other remediation activities on the potential quantitative effects of CBM-produced water on receiving streams. In many places, CBM-produced water is discharged into impoundments or channels in upper reaches of tributary watersheds where water infiltrates and does not directly contribute to streamflow. For Tongue River at State line (site 4) mean annual pumping rate of CBM-produced water during water years 2001–10 (hereinafter referred to as mean CBM pumping rate) was 6 percent of the mean of annual median streamflows during water years 2001–10 (hereinafter referred to as 2001–10 median streamflow). For main-stem Tongue River sites 5, 7, and 10, mean CBM pumping rate was 8–12 percent of 2001–10 median streamflow. For main-stem Powder River sites (sites 12, 13, and 16), mean CBM pumping rates were 26, 28, and 34 percent of 2001–10 median streamflows, respectively. For main-stem Tongue River sites analyzed by using the TSM and downstream from substantial CBM-extraction activities [Tongue River at State line (site 4), Tongue River at Tongue River Dam (site 5), Tongue River at Birney Day School (site 7), and Tongue River at Miles City (site 10)], generally small significant or nonsignificant decreases in most constituents are indicated for period 1. For period 2 for these sites, the TSM trend results do not allow confident conclusions concerning detection of effects of CBM-extraction activities on stream water quality. Detection of significant trends in major-ion constituents and properties for period 2 generally was infrequent, and direction, magnitudes, and significance of fitted trends were not strongly consistent with relative differences in water quality between stream water and CBM-produced water. The TSM indicated significant or generally large magnitude increases in median values of sodium adsorption ratio (SAR), sodium, and alkalinity for period 2 for sites 5 and 7, which might indicate potential effects of CBM-extraction activities on stream water. However, other factors, including operations of Tongue River Reservoir, irrigation activities, contributions of saline groundwater, and operations of the Decker coal mine, confound confident determination of causes of detected significant trends for sites 5 and 7. For all mainstem Tongue River sites, trends for period 2 generally are within ranges of those for period 1 before substantial CBM-extraction activities. For main-stem Powder River sites analyzed by using the TSM [Powder River at Sussex (site 11), Powder River at Arvada (site 12), Powder River at Moorhead (site 13), and Powder River near Locate (site 16)], significant or generally large magnitude decreases in median values of SAR, sodium, estimated alkalinity, chloride, fluoride, specific conductance, and dissolved solids are indicated for period 1. Patterns in trend results for period 1 for main-stem Powder River sites are consistent with effects of Salt Creek oil-brine reinjection that started in 1990. Trend results for all main-stem Powder River sites downstream from substantial CBM-extraction activities (sites 12, 13, and 16) indicate evidence of potential effects of CBM-extraction activities on stream water quality, although evidence is stronger for sites 12 and 13 than for site 16. Evidence in support of potential CBM effects includes significant increases in median values of SAR, sodium, and estimated alkalinity for period 2 for sites 12, 13, and 16 that are consistent with relative differences between stream water and CBM-produced water. Significant increases in median values of these constituents for period 2 are not indicated for Powder River at Sussex (site 11) upstream from substantial CBM-extraction activities. In interpreting the trend results, it is notable that the fitted trends evaluate changes in median concentrations and also notable that changes in median concentrations that might be attributed to CBM-extraction activities probably are more strongly evident during low to median streamflow conditions than during mean to high streamflow conditions. This observation is relevant in assessing trend results in relation to specific water-quality concerns, including effects of water-quality changes on irrigators and effects on stream biota and ecology.

Insertion of Guest Molecules into a Mixed Ligand Metal-Organic Framework via Single-Crystal-to-Single Crystal Guest Exchange

DTIC Science & Technology

2014-07-01

powder x-ray diffraction (PXRD), thermogravimentric analysis (TGA), and Fourier transform infrared (FTIR). 15. SUBJECT TERMS Metal organic frame work...the inclusion by using a variety of analytical techniques, such as powder x-ray diffraction (PXRD), thermo-gravimetric analysis (TGA), Fourier...Characterizations Analysis of the MOF and the complexes with the MOF and the guest molecules was performed using an Agilent GC-MS (Model 6890N GC and Model 5973N

"XANSONS for COD": a new small BOINC project in crystallography

NASA Astrophysics Data System (ADS)

Neverov, Vladislav S.; Khrapov, Nikolay P.

2018-04-01

"XANSONS for COD" (http://xansons4cod.com) is a new BOINC project aimed at creating the open-access database of simulated x-ray and neutron powder diffraction patterns for nanocrystalline phase of materials from the collection of the Crystallography Open Database (COD). The project uses original open-source software XaNSoNS to simulate diffraction patterns on CPU and GPU. This paper describes the scientific problem this project solves, the project's internal structure, its operation principles and organization of the final database.

Structural refinement, band-gap analysis and optical properties of GdAlO3 nanophosphors influenced by Dy3+ ion concentrations for white light emitting device applications

NASA Astrophysics Data System (ADS)

Jisha, P. K.; Naik, Ramachandra; Prashantha, S. C.; Nagaswarupa, H. P.; Nagabhushana, H.; Basavaraj, R. B.; Sharma, S. C.; Prasad, Daruka

2016-04-01

Nanosized GdAlO3 phosphors activated with Dy3+ were prepared by a combustion method. Synthesized phosphors were calcined at 1000 °C for 3 h in order to achieve crystallinity. Powder x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis was used to characterize the prepared product. The orthorhombic phase was observed in the XRD pattern. The particle size of the samples was calculated as around 25 nm. The SEM images show an irregular shape of the prepared nanophosphor. Functional groups of the phosphors were examined by Fourier transform infrared (FTIR) spectroscopy. Photoluminescence (PL) properties of Dy3+ doped GdAlO3 for near-ultraviolet excitation (352 nm) were studied in order to investigate the possibility of its use in white light emitting device applications. Judd-Ofelt intensity parameters, radiative transition rate (A T) and radiative lifetimes (τ rad) were evaluated from the emission spectrum by adopting a standard procedure. The Commission International de l’Eclairage (CIE) color coordinates and correlated color temperature (CCT) are studied for the optimized phosphor. It is found that the color coordinates of Dy3+ doped GdAlO3 powders fall in the white region of the CIE diagram, and the average CCT value was found to be about 6276 K. Therefore, the present phosphor is highly useful for display applications.

Additional studies on mixed uranyl oxide-hydroxide hydrate alteration products of uraninite from the palermo and ruggles granitic pegmatites, grafton county, New Hampshire

USGS Publications Warehouse

Foord, E.E.; Korzeb, S.L.; Lichte, F.E.; Fitzpatrick, J.J.

1997-01-01

Additional studies on an incompletely characterized secondary uranium "mineral" from the Ruggles and Palermo granitic pegmatites, New Hampshire, referred to as mineral "A" by Frondel (1956), reveal a mixture of schoepite-group minerals and related uranyl oxide-hydroxide hydrated compounds. A composite chemical analysis yielded (in wt.%): PbO 4.85 (EMP), UO3 83.5 (EMP), BaO 0.675 (av. of EMP and ICP), CaO 0.167 (av. of EMP and ICP), K2O 2.455 (av. of EMP and ICP), SrO 0.21 (ICP), ThO2 0.85 (ICP), H2O 6.9, ??99.61. Powder-diffraction X-ray studies indicate a close resemblance in patterns between mineral "A" and several uranyl oxide-hydroxide hydrated minerals, including the schoepite family of minerals and UO2(OH)2. The powder-diffraction data for mineral "A" are most similar to those for synthetic UO2.86??1.5H2O and UO2(OH)2, but other phases are likely present as well. TGA analysis of both mineral "A" and metaschoepite show similar weight-loss and first derivative curves. The dominant losses are at 100??C, with secondary events at 400?? and 600??C. IR spectra show the presence of (OH) and H2O. Uraninite from both pegmatites, analyzed by LAM-ICP-MS, shows the presence of Th, Pb, K and Ca.

First evidence of occupational asthma to argan powder in a cosmetic factory.

PubMed

Paris, C; Herin, F; Penven, E; Thaon, I; Richard, C; Jacquenet, S; Barbaud, A; Poussel, M

2016-04-01

Argan is used worldwide in numerous cosmetic products, as this fruit is supposed to have many beneficial properties on health. New cases of allergy can be expected with the growing use of argan. We investigated all workers (9) employed by a cosmetic factory and exposed to argan powder to identify possible allergies related to exposure to argan powder. Patients were investigated in the occupational disease department and, according to their symptoms, underwent pulmonary function testing, methacholine challenge, specific inhalation challenge to argan powder, skin prick tests, and immunoblotting analysis. We report three cases of occupational asthma to argan powder and a probable case of rhinitis. Fifteen argan proteins were recognized by the patients' IgE. Identification of proteins, cross-reactions to nuts, and ELISA inhibition tests suggested that some argan allergens can cross-react in vitro with hazelnut allergens, including 11S globulin and vicilin. High-level exposure to argan powder should be considered to be a potential cause of IgE-mediated allergy, and workers handling argan powder should be carefully investigated. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nano-scale composition of commercial white powders for development of latent fingerprints on adhesives.

PubMed

Jones, B J; Reynolds, A J; Richardson, M; Sears, V G

2010-09-01

Titanium dioxide based powders are regularly used in the development of latent fingerprints on dark surfaces. For analysis of prints on adhesive tapes, the titanium dioxide can be suspended in a surfactant and used in the form of a powder suspension. Commercially available products, whilst having nominally similar composition, show varying levels of effectiveness of print development, with some powders adhering to the background as well as the print. X-ray fluorescence (XRF), analytical transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and laser particle sizing of the fingerprint powders show TiO(2) particles with a surrounding coating, tens of nanometres thick, consisting of Al and Si rich material, with traces of sodium and sulphur. Such aluminosilicates are commonly used as anti-caking agents and to aid adhesion or functionality of some fingerprint powders; however, the morphology, thickness, coverage and composition of the aluminosilicates are the primary differences between the white powder formulations and could be related to variation in the efficacy of print development. Copyright © 2009 Forensic Science Society. All rights reserved.

Pods: a Powder Delivery System for Mars In-situ Organic, Mineralogic and Isotopic Analysis Instruments

NASA Technical Reports Server (NTRS)

Saha, C. P.; Bryson, C. E.; Sarrazin, P.; Blake, D. F.

2005-01-01

Many Mars in situ instruments require fine-grained high-fidelity samples of rocks or soil. Included are instruments for the determination of mineralogy as well as organic and isotopic chemistry. Powder can be obtained as a primary objective of a sample collection system (e.g., by collecting powder as a surface is abraded by a rotary abrasion tool (RAT)), or as a secondary objective (e.g, by collecting drill powder as a core is drilled). In the latter case, a properly designed system could be used to monitor drilling in real time as well as to deliver powder to analytical instruments which would perform complementary analyses to those later performed on the intact core. In addition, once a core or other sample is collected, a system that could transfer intelligently collected subsamples of power from the intact core to a suite of analytical instruments would be highly desirable. We have conceptualized, developed and tested a breadboard Powder Delivery System (PoDS) intended to satisfy the collection, processing and distribution requirements of powder samples for Mars in-situ mineralogic, organic and isotopic measurement instruments.

The study of the effect of aluminum powders dispersion on the oxidation and kinetic characteristics

NASA Astrophysics Data System (ADS)

Gorbenko, T. I.; Gorbenko, M. V.; Orlova, M. P.; Volkov, S. A.

2017-11-01

Differential-scanning calorimetry (DSC) and thermogravimetric analysis (TG) were used to study micro-sized aluminum powder ASD-4 and nano-sized powder Alex. The dependence of the oxidation process on the dispersion of the sample particles is shown. The influence of thermogravimetric conditions on the thermal regime of the process was considered, and its kinetic parameters were determined. Calculations of the activation energy and the pre-exponential factor were carried out.

Statistical Analysis of 3-Point Bending Properties of Polymer Concretes Made From Marble Powder Waste, Sand Grains, and Polyester Resin

NASA Astrophysics Data System (ADS)

Benzannache, N.; Bezazi, A.; Bouchelaghem, H.; Boumaaza, M.; Amziane, S.; Scarpa, F.

2018-01-01

The mechanical performance of concrete polymer beams subjected to 3-point bending was investigated. The polymer concrete incorporates marble powder waste and quarry sand. The results obtained showed that the type of sand, and amount of marble powder and sand aggregate affected the resistance of the polymer concrete beams significantly. The marble waste increased their bending strength by reducing the porosity of polymer concrete.

Effect of microfibril twisting in theoretical powder diffraction studies of cellulose Iß

USDA-ARS?s Scientific Manuscript database

Previous studies of calculated diffraction patterns for cellulose crystallites have suggested that the distortions arising once models have been subjected to MD simulation are likely the result of dimensional changes induced by the empirical force field, but have been unable to determine to what ext...

Powder-Collection System for Ultrasonic/Sonic Drill/Corer

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Chang, Zensheu; Blake, David; Bryson, Charles

2005-01-01

A system for collecting samples of powdered rock has been devised for use in conjunction with an ultrasonic/sonic drill/corer (USDC) -- a lightweight, lowpower apparatus designed to cut into, and acquire samples of, rock or other hard material for scientific analysis. The USDC includes a drill bit, corer, or other tool bit, in which ultrasonic and sonic vibrations are excited by an electronically driven piezoelectric actuator. The USDC advances into the rock or other material of interest by means of a hammering action and a resulting chiseling action at the tip of the tool bit. The hammering and chiseling actions are so effective that unlike in conventional twist drilling, a negligible amount of axial force is needed to make the USDC advance into the material. Also unlike a conventional twist drill, the USDC operates without need for torsional restraint, lubricant, or a sharp bit. The USDC generates powder as a byproduct of the drilling or coring process. The purpose served by the present samplecollection system is to remove the powder from the tool-bit/rock interface and deliver the powder to one or more designated location(s) for analysis or storage

Environmental, Human Health and Socio-Economic Effects of Cement Powders: The Multicriteria Analysis as Decisional Methodology.

PubMed

Moretti, Laura; Di Mascio, Paola; Bellagamba, Simona

2017-06-16

The attention to sustainability-related issues has grown fast in recent decades. The experience gained with these themes reveals the importance of considering this topic in the construction industry, which represents an important sector throughout the world. This work consists on conducting a multicriteria analysis of four cement powders, with the objective of calculating and analysing the environmental, human health and socio-economic effects of their production processes. The economic, technical, environmental and safety performances of the examined powders result from official, both internal and public, documents prepared by the producers. The Analytic Hierarchy Process permitted to consider several indicators (i.e., environmental, human health related and socio-economic parameters) and to conduct comprehensive and unbiased analyses which gave the best, most sustainable cement powder. As assumed in this study, the contribution of each considered parameter to the overall sustainability has a different incidence, therefore the procedure could be used to support on-going sustainability efforts under different conditions. The results also prove that it is not appropriate to regard only one parameter to identify the 'best' cement powder, but several impact categories should be considered and analysed if there is an interest for pursuing different, often conflicting interests.

Structure and luminescence of nanocrystalline gallium nitride synthesized by a novel polymer pyrolysis route

NASA Astrophysics Data System (ADS)

Garcia, Rafael; Hirata, Gustavo A.; Thomas, Alan C.; Ponce, Fernando A.

2006-10-01

Thermal decomposition in a horizontal quartz tube reactor of a polymer [-(CH 6N 4O) 3Ga(NO 3) 3-] in a nitrogen atmosphere, yield directly nano-structured gallium nitride (GaN) powder. The polymer was obtained by the reaction between high purity gallium nitrate (Ga(NO 3) 3) dissolved in toluene and carbohydrazide as an azotic ligand. The powder synthesized by this method showed a yellow color and elemental analysis suggested that the color is due to some carbon and oxygen impurities in the as-synthesized powder. Electron microscopy showed that the as-synthesized powders consist of a mixture of various porous particles containing nanowires and nano-sized platelets. The size of the crystallites can be controlled by annealing processes under ammonia. Photoluminescence analysis at 10 K on as-synthesized powders showed a broad red luminescence around 668 nm under UV laser excitation (He-Cd laser, 325 nm). However after annealing process the red luminescence disappears and the typical band edge emission of GaN around 357 nm (3.47 eV) and the UV band were the dominant emissions in the PL spectra.

Use of first derivative of displacement vs. force profiles to determine deformation behavior of compressed powders.

PubMed

Gharaibeh, Shadi F; Aburub, Aktham

2013-03-01

Displacement (D) vs. force (F) profiles obtained during compaction of powders have been reported by several researchers. These profiles are usually used to obtain mechanical energies associated with the compaction of powders. In this work, we obtained displacement-force data associated with the compression of six powders; Avicel PH101, Avicel PH301, pregelatinized corn starch, anhydrous lactose, dicalcium phosphate, and mannitol. The first three powders are known to deform predominantly by plastic behavior while the later ones are known to deform predominantly by brittle fracture. Displacement-force data was utilized to perform in-die Heckel analysis and to calculate the first derivative (dD/dF) of displacement-force plots. First derivative results were then plotted against mean force (F') at each point and against 1/F' at compression forces between 1 and 20 kN. Results of the in-die Heckle analysis are in very good agreement with the known deformation behavior of the compressed materials. First derivative plots show that materials that deform predominantly by plastic behavior have first derivative values (0.0006-0.0016 mm/ N) larger than those of brittle materials (0.0004 mm/N). Moreover, when dD/dF is plotted against 1/F' for each powder, a linear correlation can be obtained (R2=>0.98). The slopes of the dD/dF vs. 1/F' plots for plastically deforming materials are relatively larger than those for materials that deform by brittle behavior. It is concluded that first derivative plots of displacement-force profiles can be used to determine deformation behavior of powders.

Magnetic properties and microstructure of gas atomized MRE2(Fe, Co)14B powder with ZrC addition (MRE=Nd + Y + Dy)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, W.; Wu, Y. Q.; Dennis, K.

2009-05-12

Gas atomization powder with Zr substitutions for the MRE and ZrC additions were systematically studied. The results show that the partial substitutions of Zr and the ZrC additions effectively improved glass formability in the alloys. Scanning electron microscopy (SEM) revealed that the as-atomized powder with a particle size of less than 32 {micro}m is predominately uniform equiaxed grains with an average grain size of 1.5 {micro}m. X-ray diffraction and differential thermal analysis measurements detected very tiny amounts of amorphous phase. After annealing at 700 C for 15 min, the SEM grain microstructure exhibits a minor change, but magnetic properties aremore » substantially improved. M versus T measurements reveal that the phase composition evolved from 2:14:1 plus a small amount of 2:17 phases to a single 2:14:1 phase during the annealing process. The sieve analysis of the powders showed a particle size distribution with 90 wt % of the powder less than 45 {micro}m. The magnetic properties of the annealed powder varied with particle size. (BH){sub max} first increases with increasing particle size from 5 {micro}m, reaches the peak value in the size range of 20-25 {micro}m, and then decreases with increasing particle size. For the 20-25 {micro}m powder sample annealed at 700 C for 15 min, the (BH){sub max} of 9.6 MG Oe at room temperature and 5.6 MG Oe at 200 C were obtained, respectively.« less

Balanced mechanical resonator for powder handling device

NASA Technical Reports Server (NTRS)

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

2012-01-01

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.

Magnetic, hyperthermic and structural properties of zn substituted CaFe2O4 powders

NASA Astrophysics Data System (ADS)

Kheradmand, Abbas; Vahidi, Omid; Masoudpanah, S. M.

2018-03-01

In the present study, we have synthesized single phase Ca1 - x Zn x Fe2O4 powders by hydrothermal method. The cation distribution between the tetrahedral and octahedral sites in the spinel structure and the magnetic properties as a function of the zinc substitution have been investigated by X-ray diffraction (XRD), infrared spectroscopy and vibrating sample magnetometer methods. The obtained XRD pattern indicated that the synthesized particles had single phase cubic spinel structure with no impurity. The magnetic measurements showed that the saturation magnetization increased from 83 to 98 emu/g with the addition of zinc due to the decrease of inversity. The particle size observed by electron microscopy decreased from 1.38 to 0.97 µm with the increase of zinc addition. The Ca0.7Zn0.3Fe2O4 powders exhibited appropriate heating capability for hyperthermia applications with the maximum AC heating temperature of 20 °C and specific loss power of 9.29 W/g.

Dissolution of Uranium Oxides Under Alkaline Oxidizing Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Steven C.; Peper, Shane M.; Douglas, Matthew

2009-11-01

Bench scale experiments were conducted to determine the dissolution characteristics of uranium oxide powders (UO2, U3O8, and UO3) in aqueous peroxide-carbonate solutions. Experimental parameters included H2O2 concentration, carbonate counter cation (NH4+, Na+, K+, and Rb+), and pH. Results indicate the dissolution rate of UO2 in 1 M (NH4)2CO3 increases linearly with peroxide concentration ranging from 0.05 – 2 M. The three uranium oxide powders exhibited different dissolution patterns however, UO3 exhibited prompt complete dissolution. Carbonate counter cation affected the dissolution kinetics. There is minimal impact of solution pH, over the range 8.8 to 10.6, on initial dissolution rate.

A High-Resolution 3D Separated-Local-Field Experiment by Means of Magic-Angle Turning

PubMed

Hu; Alderman; Pugmire; Grant

1997-05-01

A 3D separated-local-field (SLF) experiment based on the 2D PHORMAT technique is described. In the 3D experiment, the conventional 2D SLF powder pattern for each chemically inequivalent carbon is separated according to their different isotropic chemical shifts. The dipolar coupling constant of a C-H pair, hence the bond distance, and the relative orientation of the chemical-shift tensor to the C-H vector can all be determined for the protonated carbons with a single measurement. As the sample turns at only about 30 Hz in a MAT experiment, the SLF patterns obtained approach those of a stationary sample, and an accuracy in the measurement similar to that obtained on a stationary sample is expected. The technique is demonstrated on 2,6-dimethoxynaphthalene, where the 13 C-1 H separated-local-field powder patterns for the six chemically inequivalent carbons are clearly identified and measured. The observed dipolar coupling for the methoxy carbon is effectively reduced by the fast rotation of the group about its C3 symmetry axis. The average angle between the C-H bond direction and the C3 rotation axis in the OCH3 group is found to be about 66°.

Microstructure Evolution of TiC Particles In Situ, Synthesized by Laser Cladding

PubMed Central

Liu, Yanhui; Ding, Jieqiong; Qu, Weicheng; Su, Yu; Yu, Zhishui

2017-01-01

In this paper, a TiC reinforcement metal matrix composite coating is produced using nickel and graphite mixing powder on the surface ofTi-6Al-4V alloy by laser radiation. The microstructure of the coatings is investigated by XRD, SEM and EDS. Results show that most of the TiC phase is granular, with a size of several micrometers, and a few of the TiC phases are petals or flakes. At the cross-section of the coatings, a few special TiC patterns are found and these TiC patterns do not always occur at the observed cross-section. The even distribution of the TiC phase in the coatings confirms that the convection of the laser-melted pool leads to the homogenization of titanium atoms from the molten substrate, and carbon atoms from the preplace powder layer, by the mass transfer. The characteristics of the TiC pattern confirm that the morphology and distribution of the primary TiC phase could be influenced by convection. Two main reasons for this are that the density of the TiC phase is lower than the liquid melt, and that the primary TiC phase precipitates from the pool with a high convection speed at high temperature. PMID:28772641

Microstructure Evolution of TiC Particles In Situ, Synthesized by Laser Cladding.

PubMed

Liu, Yanhui; Ding, Jieqiong; Qu, Weicheng; Su, Yu; Yu, Zhishui

2017-03-11

In this paper, a TiC reinforcement metal matrix composite coating is produced using nickel and graphite mixing powder on the surface ofTi-6Al-4V alloy by laser radiation. The microstructure of the coatings is investigated by XRD, SEM and EDS. Results show that most of the TiC phase is granular, with a size of several micrometers, and a few of the TiC phases are petals or flakes. At the cross-section of the coatings, a few special TiC patterns are found and these TiC patterns do not always occur at the observed cross-section. The even distribution of the TiC phase in the coatings confirms that the convection of the laser-melted pool leads to the homogenization of titanium atoms from the molten substrate, and carbon atoms from the preplace powder layer, by the mass transfer. The characteristics of the TiC pattern confirm that the morphology and distribution of the primary TiC phase could be influenced by convection. Two main reasons for this are that the density of the TiC phase is lower than the liquid melt, and that the primary TiC phase precipitates from the pool with a high convection speed at high temperature.

Modelling of growth of aflatoxigenic A. flavus isolates from red chilli powder as a function of water availability.

PubMed

Marín, Sonia; Colom, Carmen; Sanchis, Vicente; Ramos, Antonio J

2009-01-15

The aim of the present work was to apply mathematical models for the prediction of growth of aflatoxigenic moulds in powdered Capsicum fruits as a function of its water availability. As prevention of fungal growth effectively conduces to prevention of mycotoxin accumulation, the development of models for prediction of growth of mycotoxigenic fungi becomes a key step in risk management. Two aflatoxigenic A. flavus from chilli powder were grown on 3% chilli powder extract agar at different water activity levels and their growth was evaluated over time in terms of colony sizes and ergosterol accumulation. Both variables were modelled over time, and the resulting parameters (growth rates and lag phases) were modelled as a function of water availability using the Rosso cardinal model. Linear logistic regression was also applied to predict the probability of growth over storage time. Both isolates showed a similar pattern of behaviour, with decreasing growth rates and increasing lag phases with decreasing water activity level. While estimation of optimum a(w) for growth was consistently around 0.97-0.99, the minimum estimated a(w) varied from 0.82 to 0.88 depending on the isolate and on the parameters used for predictions. Comparing growth rates obtained for colony size and ergosterol accumulation, a linear relationship between them could be observed. The rate of root square ergosterol/colony diameter/unit of time was 0.25-0.27. Probabilities of growth before 10 days over 90% were estimated at a(w) 0.91, while the safe period could be extended to more than 20 days (22-29 days) if water activity was decreased to an a(w)=0.87. Finally, the probability of growth is always under 50% when water availability is under a(w) 0.85, and almost null for A. flavus UdLTA 3.147. It was concluded that for safe production, storage and transport, chillies and chilli powder must be kept under 31% mc (db) (probability of growth <50%). However, growth is unlikely to occur if chilli is kept at approx. 34% for less than 10 days, or at approx. 33% for less than 20 days. Careful hazard analysis and critical control point (HACCP) techniques during raw material production and the subsequent stages of drying, transportation, elaboration and storage are indispensable.

Analysis of the Influence of Starting Materials and Processing Conditions on the Properties of W/Cu Alloys.

PubMed

Montealegre-Meléndez, Isabel; Arévalo, Cristina; Perez-Soriano, Eva M; Neubauer, Erich; Rubio-Escudero, Cristina; Kitzmantel, Michael

2017-02-08

In this work, a study of the influence of the starting materials and the processing time used to develop W/Cu alloys is carried out. Regarding powder metallurgy as a promising fabrication route, the difficulties in producing W/Cu alloys motivated us to investigate the influential factors on the final properties of the most industrially demanding alloys: 85-W/15-Cu, 80-W/20-Cu, and 75-W/25-Cu alloys. Two different tungsten powders with large variation among their particle size-fine (W f ) and coarse (W c ) powders-were used for the preparation of W/Cu alloys. Three weight ratios of fine and coarse (W f :W c ) tungsten particles were analyzed. These powders were labelled as "tungsten bimodal powders". The powder blends were consolidated by rapid sinter pressing (RSP) at 900 °C and 150 MPa, and were thus sintered and compacted simultaneously. The elemental powders and W/Cu alloys were studied by optical microscopy (OM) and scanning electron microscopy (SEM). Thermal conductivity, hardness, and densification were measured. Results showed that the synthesis of W/Cu using bimodal tungsten powders significantly affects the final alloy properties. The higher the tungsten content, the more noticeable the effect of the bimodal powder. The best bimodal W powder was the blend with 10 wt % of fine tungsten particles (10-W f :90-W c ). These specimens present good values of densification and hardness, and higher values of thermal conductivity than other bimodal mixtures.

Identification of a Herbal Powder by Deoxyribonucleic Acid Barcoding and Structural Analyses.

PubMed

Sheth, Bhavisha P; Thaker, Vrinda S

2015-10-01

Authentic identification of plants is essential for exploiting their medicinal properties as well as to stop the adulteration and malpractices with the trade of the same. To identify a herbal powder obtained from a herbalist in the local vicinity of Rajkot, Gujarat, using deoxyribonucleic acid (DNA) barcoding and molecular tools. The DNA was extracted from a herbal powder and selected Cassia species, followed by the polymerase chain reaction (PCR) and sequencing of the rbcL barcode locus. Thereafter the sequences were subjected to National Center for Biotechnology Information (NCBI) basic local alignment search tool (BLAST) analysis, followed by the protein three-dimension structure determination of the rbcL protein from the herbal powder and Cassia species namely Cassia fistula, Cassia tora and Cassia javanica (sequences obtained in the present study), Cassia Roxburghii, and Cassia abbreviata (sequences retrieved from Genbank). Further, the multiple and pairwise structural alignment were carried out in order to identify the herbal powder. The nucleotide sequences obtained from the selected species of Cassia were submitted to Genbank (Accession No. JX141397, JX141405, JX141420). The NCBI BLAST analysis of the rbcL protein from the herbal powder showed an equal sequence similarity (with reference to different parameters like E value, maximum identity, total score, query coverage) to C. javanica and C. roxburghii. In order to solve the ambiguities of the BLAST result, a protein structural approach was implemented. The protein homology models obtained in the present study were submitted to the protein model database (PM0079748-PM0079753). The pairwise structural alignment of the herbal powder (as template) and C. javanica and C. roxburghii (as targets individually) revealed a close similarity of the herbal powder with C. javanica. A strategy as used here, incorporating the integrated use of DNA barcoding and protein structural analyses could be adopted, as a novel rapid and economic procedure, especially in cases when protein coding loci are considered. Authentic identification of plants is essential for exploiting their medicinal properties as well as to stop the adulteration and malpractices with the trade of the same. A herbal powder was obtained from a herbalist in the local vicinity of Rajkot, Gujarat. An integrated approach using DNA barcoding and structural analyses was carried out to identify the herbal powder. The herbal powder was identified as Cassia javanica L.

The influence of pore formers on the microstructure of plasma-sprayed NiO-YSZ anodes

NASA Astrophysics Data System (ADS)

Poon, Michael; Kesler, Olivera

2012-07-01

Four types of pore formers: high-density polyethylene (HDPE), polyether-ether-ketone (PEEK), mesocarbon-microbead (MCMB) carbon powder, and baking flour, are processed and characterized, then incorporated with NiO-YSZ nano-agglomerate powder to produce plasma sprayed SOFC anode coatings. Scanning electron microscopy (SEM) of the coating microstructure, gas permeability measurements, and porosity determinations by image analysis are used to evaluate the effectiveness of each potential pore former powder. Under the spray conditions studied, the flour and MCMB pore former powders are effective as plasma sprayed pore formers, increasing the permeability of the coatings by factors of four and two, respectively, compared to a similarly sprayed NiO-YSZ coating without pore formers. The HDPE powder is unable to survive the plasma spray process and does not contribute to the final coating porosity. The PEEK pore former, though ineffective with the current powder characteristics and spray parameters, exhibits the highest relative deposition efficiency and the most favorable thermal characteristics.

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

PubMed

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

2012-10-01

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

Effect of microencapsulated fat powders on rheological characteristics of biscuit dough and quality of biscuits.

PubMed

Sudha, M L; Chetana, R; Reddy, S Yella

2014-12-01

The effect of microencapsulated fat powders on the rheological characteristics and quality of biscuits were studied and compared with the control native fat normally used in the biscuit industry. Commercial bakery fat was encapsulated using sodium caseinate or skimmed milk powder (SMP) and the fat content in the powders was in the range of 73 - 78 % for sodium caseinate, whereas it ranged between 57.5 and 61 % with SMP and the sugar content was in the range of 9.8 - 17.5 %. The rheological characteristics indicated that with high sodium caseinate and SMP, the doughs were more elastic. The TPA analysis showed that with increasing the casein content in the fat powder, the dough hardness increased, and the doughs were less cohesive. The quality of biscuits was comparable with lower amount of encapsulating agents. Powders with lower amount of agents had comparable benefits on the rheological characteristics of the dough and biscuit quality.

Optimization of Bread Enriched with Garcinia mangostana Pericarp Powder

NASA Astrophysics Data System (ADS)

Ibrahim, U. K.; Salleh, R. Mohd; Maqsood-ul-Hague, S. N. S.; Hashib, S. Abd; Karim, S. F. Abd

2018-05-01

The aim of present work is to optimize the formulation of bread enhanced with Garcinia mangostana pericarp powder with the combination of baking process conditions. The independent variables used were baking time (15 - 30 minutes), baking temperature (180 - 220°C) and pericarp powder concentration (0.5 - 2.0%). The physical and chemical properties of bread sample such as antioxidant activity, phenolic content, moisture analysis and colour parameters were studied. Bread dough without fortification of pericarp powder was used as control. Data obtained were analyzed by multiple regressions and the significant model such as linear and quadratic with variables interactions were used. As a conclusion, the optimum baking conditions were found at 213°C baking temperature with 23 minutes baking time and addition of 0.87% for Garcinia mangostana pericarp powder to the bread formulation.

Mechanical alloying, characterization and consolidation of Ti-Al-Ni alloys

NASA Technical Reports Server (NTRS)

Nash, P.; Higgins, G. T.; Dillinger, N.; Hwang, S. J.; Kim, H.

1989-01-01

Mechanical alloying is being investigated as a processing route for the production of aluminide intermetallics. This program involves powder production and characterization, consolidation and thermal treatments and determination of microstructure-property relationships. An attritor mill is being used to produce powder in lots up to 1000 grams and the processing parameters are being systematically varied to establish the optimum milling conditions. The mill is being instrumented to generate data related to the processing to provide a basis for theoretical modeling. Powder is being characterized using thermal analysis, optical and electron microscopy and X-ray diffraction. Particle size distributions and powder density are being determined. Consolidation of the powder is being approached in several different ways including, cold isostatic pressing, sintering, extrusion and hot pressing. The results of the program so far will be presented and future directions discussed.

Enhancement of broccoli indole glucosinolates by methyl jasmonate treatment and effects on prostate carcinogenesis.

PubMed

Liu, Ann G; Juvik, John A; Jeffery, Elizabeth H; Berman-Booty, Lisa D; Clinton, Steven K; Erdman, John W

2014-11-01

Broccoli is rich in bioactive components, such as sulforaphane and indole-3-carbinol, which may impact cancer risk. The glucosinolate profile of broccoli can be manipulated through treatment with the plant stress hormone methyl jasmonate (MeJA). Our objective was to produce broccoli with enhanced levels of indole glucosinolates and determine its impact on prostate carcinogenesis. Brassica oleracea var. Green Magic was treated with a 250 μM MeJA solution 4 days prior to harvest. MeJA-treated broccoli had significantly increased levels of glucobrassicin, neoglucobrassicin, and gluconasturtiin (P < .05). Male transgenic adenocarcinoma of mouse prostate (TRAMP) mice (n = 99) were randomized into three diet groups at 5-7 weeks of age: AIN-93G control, 10% standard broccoli powder, or 10% MeJA broccoli powder. Diets were fed throughout the study until termination at 20 weeks of age. Hepatic CYP1A was induced with MeJA broccoli powder feeding, indicating biological activity of the indole glucosinolates. Following ∼ 15 weeks on diets, neither of the broccoli treatments significantly altered genitourinary tract weight, pathologic score, or metastasis incidence, indicating that broccoli powder at 10% of the diet was ineffective at reducing prostate carcinogenesis in the TRAMP model. Whereas broccoli powder feeding had no effect in this model of prostate cancer, our work demonstrates the feasibility of employing plant stress hormones exogenously to stimulate changes in phytochemical profiles, an approach that may be useful for optimizing bioactive component patterns in foods for chronic-disease-prevention studies.

Investigation of the Deposition and Densification Parameters on the Mechanical Properties of Pressurized Spray Deposited (PSD) 3-D Printed Ceramic Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menchhofer, Paul A.; Becker, Benjamin

Oak Ridge National Laboratory (ORNL) and HotEnd Works teamed to investigate the use of pressurized spray deposition (PSD) technology for the production of ceramic parts via additive manufacturing. Scanning electron microscopy of sintered parts provided by HotEnd Works revealed voids large enough to compromise the mechanical properties of PSD manufactured parts. Scanning electron microscopy and particle size analysis of the alumina oxide powder feedstocks indicated that the powders contained some large particles and some agglomerations in the powder. Further classification of the powder feedstocks and removal of the agglomerates by sonication in the liquid used for the PSD process aremore » recommended. Analysis of sintered parts indicated that the sonic modulus for the alumina part is consistent with other known values for alumina. The density for this part was determined by standard Archimedes immersion density methods and was found to be > 99.7 % of the theoretical density for pure alumina.« less

Bibliography of US geological survey reports on coal drilling and geophysical logging projects, and related reports on geologic uses, Powder River Basin, Montana and Wyoming, 1973-1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cathcart, J.D.

1984-01-01

This bibliography includes reports on coal drilling, geophysical logging projects, and related geologic uses, in the Powder River Basin of Montana and Wyoming. Reports on chemical analyses of Powder River Basin coals, coal quality, methane studies, and geotechnical studies are also included, as are EMRIA (Energy Mineral Rehabilitation Inventory and Analysis) reports on resource and potential reclamation of selected study areas in Montana and Wyoming.

Compact, Non-Pneumatic Rock-Powder Samplers

NASA Technical Reports Server (NTRS)

Sherrit, Stewart; Bar-Cohen, Yoseph; Badescu, Mircea; Bao, Xiaoqi; Chang, Zensheu; Jones, Christopher; Aldrich, Jack

2008-01-01

Tool bits that automatically collect powdered rock, permafrost, or other hard material generated in repeated hammering action have been invented. The present invention pertains to the special case in which it is desired to collect samples in powder form for analysis by x-ray diffraction and possibly other techniques. The present invention eliminates the need for both the mechanical collection equipment and the crushing chamber and the pneumatic collection equipment of prior approaches, so that it becomes possible to make the overall sample-acquisition apparatus more compact.

Acetone Powder From Dormant Seeds of Ricinus communis L

NASA Astrophysics Data System (ADS)

Cavalcanti, Elisa D. C.; Maciel, Fábio M.; Villeneuve, Pierre; Lago, Regina C. A.; Machado, Olga L. T.; Freire, Denise M. G.

The influence of several factors on the hydrolytic activity of lipase, present in the acetone powder from dormant castor seeds (Ricinus communis) was evaluated. The enzyme showed a marked specificity for short-chain substrates. The best reaction conditions were an acid medium, Triton X-100 as the emulsifying agent and a temperature of 30°C. The lipase activity of the acetone powder of different castor oil genotypes showed great variability and storage stability of up to 90%. The toxicology analysis of the acetone powder from genotype Nordestina BRS 149 showed a higher ricin (toxic component) content, a lower 2S albumin (allergenic compound) content, and similar allergenic potential compared with untreated seeds.

Effect of calcination temperature on microstructure, dielectric, magnetic and optical properties of Ba0.7La0.3Fe11.7Co0.3O19 hexaferrites

NASA Astrophysics Data System (ADS)

Kaur, Talwinder; Kaur, Barjinder; Bhat, Bilal H.; Kumar, Sachin; Srivastava, A. K.

2015-01-01

M-type barium hexaferrite Ba0.7La0.3Fe11.7Co0.3O19 (BaLCM) powder, synthesized using sol gel auto combustion method, heat treated at 700, 900, 1100 and 1200 °C. X ray diffraction (XRD) powder patterns of heat treated samples show the formation of pure phase of M-type hexaferrite after 700 °C. Thermo gravimetric analysis (TGA) reveals that the weight loss of BaLCM becomes constant after 680 °C. The presence of two prominent peaks, at 432 cm-1 and 586 cm-1 in Fourier Transform Infrared Spectroscopy (FT-IR) spectra, gives the idea of formation of M-type hexaferrites. The M-H curve obtained from Vibrating Sample Magnetometer (VSM) were used to calculate saturation magnetization (MS), retentivity (Mr), squareness ration (SR) and coercivity (Hc). The maximum value of coercivity (5602 Oe) is found at 900 °C. The band gap dependency on temperature was studied using UV-vis NIR spectroscopy. The dielectric constant has been found to be high at low frequency but it decreases with increase in frequency. Such kind of dielectric behavior is explained on the basis of Koop's phenomenological theory and Maxwell Wagner theory.

K3Na(SO4)2 : Eu nanoparticles for high dose of ionizing radiation

NASA Astrophysics Data System (ADS)

Sahare, P. D.; Ranjan, Ranju; Salah, Numan; Lochab, S. P.

2007-02-01

K3Na(SO4)2 : Eu nanocrystalline powder was synthesized by the chemical co-precipitation method. The x-ray diffraction pattern of the nanomaterials shows a hexagonal structure for its crystals having grain size of ~28 nm. Transmission electron microscopy revealed that the K3Na(SO4)2 : Eu nanoparticles are single crystals with almost a uniform shape and size. Thermoluminescence (TL) was taken after irradiating the samples at various exposures of γ-rays from a 60Co source. A prominent TL glow peak is observed at 423 K along with three small peaks/shoulders at around 382, 460 and 509 K. The observed TL sensitivity of the prepared nanocrystalline powder is around 4 times more than that of LiF : Mg,Ti (TLD-100) phosphor. The 423 K peak of the nanomaterial phosphor eventually shows a near linear response with exposures increasing up to very high values (as high as 70 kGy), where all the other TLD phosphors saturate. This property along with its other desired properties such as high sensitivity, relatively simple glow curve structure and low fading makes the nanocrystalline phosphor a suitable dosimeter to estimate low as well as high exposures of γ-rays. TL analysis using the glow curve deconvolution technique was also done for determining different trapping parameters.

Preparation and characterization of adefovir dipivoxil-stearic acid cocrystal with enhanced physicochemical properties.

PubMed

Seo, Jeong-Woong; Hwang, Kyu-Min; Lee, Sung-Hoon; Kim, Dong-Wook; Park, Eun-Seok

2017-06-11

The objectives of this study were to prepare cocrystal composed of adefovir dipivoxil (AD) and stearic acid (SA) and to investigate the enhanced properties of the cocrystal. The cocrystal was prepared by antisolvent precipitation and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). The enhanced properties were evaluated by dissolution testing, permeability studies, and powder rheology analysis. The AD raw material has a cuboid-like crystal and the cocrystal has a needle shape. In the FT-IR study, there were bathochromic shifts caused by the hydrogen bonding. The melting point of the cocrystal was 52.9 °C, which was lower than that of AD. The XRPD pattern also had distinct differences, supporting the formation of a new crystalline form. The cocrystal showed changes in the lattice energy and the solvation strength, which caused an enhanced dissolution. The permeability was increased due to the SA, which acts as a P-gp inhibitor. The tabletability was enhanced due to the altered crystal habit. In conclusion, cocrystal containing AD and SA was successfully prepared, presenting advantages such as enhanced solubility, tabletability, and permeability. The use of the cocrystal is a desirable approach for the improved physicochemical properties.

Trithallium hydrogen bis(sulfate), Tl(3)H(SO(4))(2), in the super-ionic phase by X-ray powder diffraction.

PubMed

Matsuo, Yasumitsu; Kawachi, Shinya; Shimizu, Yuya; Ikehata, Seiichiro

2002-07-01

The structure of trithallium hydrogen bis(sulfate), Tl(3)H(SO(4))(2), in the super-ionic phase has been analyzed by Rietveld analysis of the X-ray powder diffraction pattern. Atomic parameters based on the isotypic Rb(3)H(SeO(4))(2) crystal in space group R3m in the super-ionic phase were used as the starting model, because it has been shown from the comparison of thermal and electric properties in Tl(3)H(SO(4))(2) and M(3)H(SO(4))(2) type crystals (M = Rb, Cs or NH(4)) that the room-temperature Tl(3)H(SO(4))(2) phase is isostructural with the high-temperature R3m-symmetry M(3)H(SO(4))(2) crystals. The structure was determined in the trigonal space group R3m and the Rietveld refinement shows that an hydrogen-bond O-H...O separation is slightly shortened compared with O-H...O separations in isotypic M(3)H(SeO(4))(2) crystals. In addition, it was found that the distortion of the SO(4) tetrahedra in Tl(3)H(SO(4))(2) is less than that in isotypic crystals.

Fullerene-like (IF) Nb(x)Mo(1-x)S2 nanoparticles.

PubMed

Deepak, Francis Leonard; Cohen, Hagai; Cohen, Sidney; Feldman, Yishay; Popovitz-Biro, Ronit; Azulay, Doron; Millo, Oded; Tenne, Reshef

2007-10-17

IF-Mo1-xNbxS2 nanoparticles have been synthesized by a vapor-phase reaction involving the respective metal halides with H2S. The IF-Mo1-xNbxS2 nanoparticles, containing up to 25% Nb, were characterized by a variety of experimental techniques. Analysis of the powder X-ray powder diffraction, X-ray photoelectron spectroscopy, and different electron microscopy techniques shows that the majority of the Nb atoms are organized as nanosheets of NbS2 within the MoS2 host lattice. Most of the remaining Nb atoms (3%) are interspersed individually and randomly in the MoS2 host lattice. Very few Nb atoms, if any, are intercalated between the MoS2 layers. A sub-nanometer film of niobium oxide seems to encoat the majority of the nanoparticles. X-ray photoelectron spectroscopy in the chemically resolved electrical measurement mode (CREM) and scanning probe microscopy measurements of individual nanoparticles show that the mixed IF nanoparticles are metallic independent of the substitution pattern of the Nb atoms in the lattice of MoS2 (whereas unsubstituted IF-MoS2 nanoparticles are semiconducting). Furthermore the IF-Mo1-xNbxS2 nanoparticles are found to exhibit interesting single electron tunneling effects at low temperatures.

Multivariate Analysis of Effects of Asthmatic Patient Respiratory Profiles on the In Vitro Performance of a Reservoir Multidose and a Capsule-Based Dry Powder Inhaler.

PubMed

Buttini, Francesca; Pasquali, Irene; Brambilla, Gaetano; Copelli, Diego; Alberi, Massimiliano Dagli; Balducci, Anna Giulia; Bettini, Ruggero; Sisti, Viviana

2016-03-01

The aim of this work was to evaluate the effect of two different dry powder inhalers, of the NGI induction port and Alberta throat and of the actual inspiratory profiles of asthmatic patients on in-vitro drug inhalation performances. The two devices considered were a reservoir multidose and a capsule-based inhaler. The formulation used to test the inhalers was a combination of formoterol fumarate and beclomethasone dipropionate. A breath simulator was used to mimic inhalatory patterns previously determined in vivo. A multivariate approach was adopted to estimate the significance of the effect of the investigated variables in the explored domain. Breath simulator was a useful tool to mimic in vitro the in vivo inspiratory profiles of asthmatic patients. The type of throat coupled with the impactor did not affect the aerodynamic distribution of the investigated formulation. However, the type of inhaler and inspiratory profiles affected the respirable dose of drugs. The multivariate statistical approach demonstrated that the multidose inhaler, released efficiently a high fine particle mass independently from the inspiratory profiles adopted. Differently, the single dose capsule inhaler, showed a significant decrease of fine particle mass of both drugs when the device was activated using the minimum inspiratory volume (592 mL).

Enhanced luminescence in Mg{sup 2+} codoped CaTiO{sub 3}:Eu{sup 3+} phosphor prepared by solid state reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vandana, C. Sai; Rudramadevi, B. Hemalatha

2016-05-23

CaTiO{sub 3} phosphors doped with Eu{sup 3+} and codoped with Mg{sup 2+} were prepared by Solid State Reaction method. The powders were characterized by X-ray diffraction, SEM with EDS, Raman scattering, and photoluminescence spectroscopy. The Crystalline phase and vibrational modes of the phosphors were studied using XRD pattern and Raman Spectrum respectively. The morphological studies of the phosphor samples were carried out using SEM analysis. From PL spectra we have observed two prominent red emission peaks around at 595 nm ({sup 5}D{sub 0}→{sup 7}F{sub 1}), 619 nm ({sup 5}D{sub 0}→{sup 7}F{sub 2}) with the excitation of 399 nm for Eu{supmore » 3+} doped CaTiO{sub 3} powders. The PL intensity of CaTiO{sub 3}:Eu{sup 3+} phosphor is enhanced significantly on codoping with Mg{sup 2+}. The observed enhanced emissions are due to energy transfer from Mg{sup 2+} to Eu{sup 3+}, which is due to radiative recombination. Eu{sup 3+} doped phosphors are well known to be promising materials for electroluminescent devices, optical amplifiers, and lasers.« less

Low-temperature x-ray crystal structure analysis of the cage-structured compounds M Be13 (M =La,Sm, and U)

NASA Astrophysics Data System (ADS)

Hidaka, Hiroyuki; Nagata, Ryoma; Tabata, Chihiro; Shimizu, Yusei; Miura, Naoyuki; Yanagisawa, Tatsuya; Amitsuka, Hiroshi

2018-05-01

The beryllides M Be13 (M = rare earths and actinides) crystallize in a NaZn13-type cubic structure, which can be categorized as a cage-structured compound. In this study, powder x-ray diffraction measurements have been performed on LaBe13,SmBe13, and UBe13 in the temperature range between 7 and 300 K in order to investigate their crystallographic characteristics systematically. They keep the NaZn13-type cubic structure down to the lowest temperature. We estimated their Debye temperature to be 600-750 K from analyses of the temperature dependence of a lattice parameter, being in good agreement with the values reported previously. Rietveld refinements on the obtained powder patterns revealed that the M atom in the 8 a site is located in an almost ideal snub cube formed by 24 BeII atoms in the 96 i site, whose caged structure is unchanged even at the low temperatures. In addition, it is argued from the temperature variation of an isotropic mean-square displacement parameter that the M Be13 compounds commonly have a low-energy phonon mode, which can be described by a model assuming an Einstein oscillation of the M atom with a characteristic temperature of ˜160 K.

Thermal analysis and evolution of shape loss phenomena during polymer burnout in powder metal processing

NASA Astrophysics Data System (ADS)

Enneti, Ravi Kumar

2005-07-01

Powder metallurgy technology involves manufacturing of net shape or near net shape components starting from metal powders. Polymers are used to provide lubrication during shaping and handling strength to the shaped component. After shaping, the polymers are removed from the shaped components by providing thermal energy to burnout the polymers. Polymer burnout is one of the most critical step in powder metal processing. Improper design of the polymer burnout cycle will result in formation of defects, shape loss, or carbon contamination of the components. The effect of metal particles on polymer burnout and shape loss were addressed in the present research. The study addressing the effect of metal powders on polymer burnout was based on the hypothesis that metal powders act to catalyze polymer burnout. Thermogravimetric analysis (TGA) on pure polymer, ethylene vinyl acetate (EVA), and on admixed powders of 316L stainless steel and 1 wt. % EVA were carried out to verify the hypothesis. The effect of metal powders additions was studied by monitoring the onset temperature for polymer degradation and the temperature at which maximum rate of weight loss occurred from the TGA data. The catalytic behavior of the powders was verified by varying the particle size and shape of the 316L stainless powder. The addition of metal particles lowered the polymer burnout temperatures. The onset temperature for burnout was found to be sensitive to the surface area of the metal particle as well as the polymer distribution. Powders with low surface area and uniform distribution of polymer showed a lower burnout temperature. The evolution of shape loss during polymer burnout was based on the hypothesis that shape loss occurs during the softening of the polymer and depends on the sequence of chemical bonding in the polymer during burnout. In situ observation of shape loss was carried out on thin beams compacted from admixed powders of 316L stainless steel and 1 wt. % ethylene vinyl acetate (EVA). The results showed that shape loss primarily occurs by viscous creep during the softening of the polymer. At the onset of burnout of EVA, a recovery in shape loss was observed. The recovery occurred primarily during the first stage burnout of EVA and was attributed to the formation of polyethylene co-polyacetylene which forms with a carbon double bond. The in situ strength was also found to increase during the formation of polyethylene co-polyacetylene. No recovery of shape loss was observed during burnout of polymers (polyethylene and polypropylene) which convert to yield hydrocarbons without forming carbon double bonds. (Abstract shortened by UMI.)

Effects of particle size of fiberglass-resin powder from PCBs on the properties and volatile behavior of phenolic molding compound.

PubMed

Guo, Jie; Rao, Qunli; Xu, Zhenming

2010-03-15

Fiberglass-resin powder (FR powder), a mixture of resin powder and glass fibers reclaimed from pulverized waste printed circuit boards (PCBs), is used as a partial substitute of wood flour in the production of modified phenolic molding compound (MPMC). The results show that incorporation of FR powder into MPMC as a filler enhances the thermal stability represented by heat deflection temperature (HDT). MPMC with FR powder smaller than 0.07 mm shows better properties, with a flexural strength of 73 MPa, a charpy notched impact strength of 3.0 kJ/m(2), a HDT of 167 degrees C, and a dielectric strength of 3.7 MV/m, all of which meet the standard data. Thermogravimetric analysis shows that thermal degradation of MPMC mainly includes three steps, and over 55% weight loss of MPMC occurs between temperatures of 370 degrees C and 575 degrees C. Phenol is the main volatile compound released from molding powder during the production of molding product. After molding powder cures to molding product, low level of residual phenol is detected. All the results indicate that the MPMC can be used as a new type of molding compound. (c) 2009 Elsevier B.V. All rights reserved.

Invasive species and coal bed methane development in the Powder River Basin, Wyoming

USGS Publications Warehouse

Bergquist, E.; Evangelista, P.; Stohlgren, T.J.; Alley, N.

2007-01-01

One of the fastest growing areas of natural gas production is coal bed methane (CBM) due to the large monetary returns and increased demand for energy from consumers. The Powder River Basin, Wyoming is one of the most rapidly expanding areas of CBM development with projections of the establishment of up to 50,000 wells. CBM disturbances may make the native ecosystem more susceptible to invasion by non-native species, but there are few studies that have been conducted on the environmental impacts of this type of resource extraction. To evaluate the potential effects of CBM development on native plant species distribution and patterns of non-native plant invasion, 36 modified Forest Inventory and Analysis plots (each comprised of four 168-m2 subplots) were established in the Powder River Basin, Wyoming. There were 73 168-m2 subplots on control sites; 42 subplots on secondary disturbances; 14 on major surface disturbances; eight on well pads; and seven on sites downslope of CBM wells water discharge points. Native plant species cover ranged from 39.5 ?? 2.7% (mean ?? 1 SE) in the secondary disturbance subplots to 17.7 ?? 7.5% in the pad subplots. Non-native plant species cover ranged from 31.0 ?? 8.4% in the discharge areas to 14.7 ?? 8.9% in the pad subplots. The control subplots had significantly less non-native species richness than the combined disturbance types. The combined disturbance subplots had significantly greater soil salinity than the control sites. These results suggest that CBM development and associated disturbances may facilitate the establishment of non-native plants. Future research and management decisions should consider the accumulative landscape-scale effects of CBM development on preserving native plant diversity. ?? Springer Science+Business Media B.V. 2006.

Direct Compositional Characterization of (U,Th)O2 Powders, Microspheres, and Pellets Using TXRF.

PubMed

Dhara, Sangita; Prabhat, Parimal; Misra, N L

2015-10-20

A total reflection X-ray fluorescence (TXRF) analysis method for direct compositional characterization of sintered and green (U,Th)O2 samples in different forms (e.g., pellets, powders, and microspheres) without sample dissolution has been developed for the first time. The methodology involves transfer of only a few nanograms of the sample on the TXRF sample support by gently rubbing the samples on supports or taking their tiny uniform slurry in collodion on the sample support, drying them to make thin film, and measuring the TXRF spectra of the specimens thus prepared. This approach minimizes the matrix effects. Uranium determinations from the TXRF spectra of such specimens were made with respect to thorium, considering it as an internal standard. Samples having uranium atom percent (at%) from 0 to 100 in (U,Th)O2 were analyzed for uranium in comparison to thorium. The results showed an average precision of 2.6% (RSD, 2σ, n = 8). The TXRF-determined results deviated from expected values within 5%. The TXRF results were compared with those of biamperometry with good agreement. The lattice parameters of the solid solutions were calculated using their XRD patterns. A good correlation between lattice parameters and TXRF-determined U at% and between TXRF-determined U at% and expected U at%, calculated on the basis of preparation of (U,Th)O2 solid solutions, was obtained. The developed method is capable of analyzing (U,Th)O2 samples directly with almost negligible sample preparation and is well suited for radioactive samples. The present study suggests that this method can be extended for the determination of U,Th and Pu in other nuclear fuel materials (e.g., nitrides, carbides, etc.) in the form of pellets, powders, and microspheres after suitable modifications in sample handling procedure.

Development of high performance liquid chromatography method for miconazole analysis in powder sample

NASA Astrophysics Data System (ADS)

Hermawan, D.; Suwandri; Sulaeman, U.; Istiqomah, A.; Aboul-Enein, H. Y.

2017-02-01

A simple high performance liquid chromatography (HPLC) method has been developed in this study for the analysis of miconazole, an antifungal drug, in powder sample. The optimized HPLC system using C8 column was achieved using mobile phase composition containing methanol:water (85:15, v/v), a flow rate of 0.8 mL/min, and UV detection at 220 nm. The calibration graph was linear in the range from 10 to 50 mg/L with r 2 of 0.9983. The limit of detection (LOD) and limit of quantitation (LOQ) obtained were 2.24 mg/L and 7.47 mg/L, respectively. The present HPLC method is applicable for the determination of miconazole in the powder sample with a recovery of 101.28 % (RSD = 0.96%, n = 3). The developed HPLC method provides short analysis time, high reproducibility and high sensitivity.

Phase quantification by X-ray photoemission valence band analysis applied to mixed phase TiO2 powders

NASA Astrophysics Data System (ADS)

Breeson, Andrew C.; Sankar, Gopinathan; Goh, Gregory K. L.; Palgrave, Robert G.

2017-11-01

A method of quantitative phase analysis using valence band X-ray photoelectron spectra is presented and applied to the analysis of TiO2 anatase-rutile mixtures. The valence band spectra of pure TiO2 polymorphs were measured, and these spectral shapes used to fit valence band spectra from mixed phase samples. Given the surface sensitive nature of the technique, this yields a surface phase fraction. Mixed phase samples were prepared from high and low surface area anatase and rutile powders. In the samples studied here, the surface phase fraction of anatase was found to be linearly correlated with photocatalytic activity of the mixed phase samples, even for samples with very different anatase and rutile surface areas. We apply this method to determine the surface phase fraction of P25 powder. This method may be applied to other systems where a surface phase fraction is an important characteristic.

A comparative study of the use of powder X-ray diffraction, Raman and near infrared spectroscopy for quantification of binary polymorphic mixtures of piracetam.

PubMed

Croker, Denise M; Hennigan, Michelle C; Maher, Anthony; Hu, Yun; Ryder, Alan G; Hodnett, Benjamin K

2012-04-07

Diffraction and spectroscopic methods were evaluated for quantitative analysis of binary powder mixtures of FII(6.403) and FIII(6.525) piracetam. The two polymorphs of piracetam could be distinguished using powder X-ray diffraction (PXRD), Raman and near-infrared (NIR) spectroscopy. The results demonstrated that Raman and NIR spectroscopy are most suitable for quantitative analysis of this polymorphic mixture. When the spectra are treated with the combination of multiplicative scatter correction (MSC) and second derivative data pretreatments, the partial least squared (PLS) regression model gave a root mean square error of calibration (RMSEC) of 0.94 and 0.99%, respectively. FIII(6.525) demonstrated some preferred orientation in PXRD analysis, making PXRD the least preferred method of quantification. Copyright © 2012 Elsevier B.V. All rights reserved.

Reverse engineering the physical chemistry of making Egyptian faience through compositional analysis of the cementation process

NASA Astrophysics Data System (ADS)

Pourattar, Parisa

The cementation process of making Egyptian faience, reported by Hans Wulff from a workshop in Qom, Iran, has not been easy to replicate and various views have been set forth to understand the transport of materials from the glazing powder to the surfaces of the crushed quartz beads. Replications of the process fired to 950° C and under-fired to 850° C were characterized by electron beam microprobe analysis (EPMA), petrographic thin section analysis, and scanning electron microscopy with energy dispersive x-ray analysis (SEM-EDS). Chemical variations were modeled using thermal data, phase diagrams, and copper vaporization experiments. These replications were compared to 52 examples from various collections, including 20th century ethnographic collections of beads, glazing powder and plant ash, 12th century CE beads and glazing powder from Fustat (Old Cairo), Egypt, and to an earlier example from Abydos, Egypt in the New Kingdom and to an ash example from the Smithsonian Institution National Museum of Natural History.

Magnetic and magneto elastic properties of cobalt ferrite ceramic compacted through cold isostatic pressing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Indla, Srinivas; Das, Dibakar, E-mail: ddse@uohyd.ernet.in; Chelvane, Arout

2016-05-06

Nano crystalline CoFe{sub 2}O{sub 4} powder was prepared by combustion synthesis method. As synthesized powder was calcined at an appropriate condition to remove the impurities and to promote phase formation. Phase pure CoFe{sub 2}O{sub 4} powder was pressed into cylindrical rod at an applied pressure of 200 MPa using a cold isostatic pressing. Sintering of the green compact at 1350°c for 12 hrs resulted in sintered cylindrical rod with ~85% of the theoretical density. Single phase cubic spinel structure was observed in the powder x-ray diffraction pattern of the sintered pellet. Scanning electron micrographs (SEM) of the as sintered pelletmore » revealed the microstructure to be composed of ferrite grains of average size ~4 µm. Saturation magnetization of 72 emu/g and coercivity of 355 Oe were observed for cobalt ferrite sample. The magnetostriction was measured on a circular disc (12 mm diameter and 12 mm length) with the strain gauge (350 Ω) mounted on the flat surface of the circular disc. Magnetostriciton of 180 ppm and strain derivative of 1 × 10{sup −9} m/A were observed for the sintered CoFe{sub 2}O{sub 4} sample.« less

Field evaluation of some bait additives against Indian crested porcupine (Hystrix indica) (Rodentia: Hystricidae).

PubMed

Mushtaq, Muhammad; Hussain, Iftikhar; Mian, Afsar; Munir, Shahid; Ahmed, Irfan; Khan, Abdul Aziz

2013-09-01

This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut-maize (1:1) as basic bait. All the additives were tested under a no-choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non-significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut-maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

Association between healthy maternal dietary pattern and risk for gestational diabetes mellitus.

PubMed

Tryggvadottir, E A; Medek, H; Birgisdottir, B E; Geirsson, R T; Gunnarsdottir, I

2016-02-01

Gestational diabetes mellitus (GDM) is associated with negative health effects for mother and child. The aim was to investigate the association between maternal dietary patterns and GDM. Prospective observational study including 168 pregnant women aged 18-40 years, recruited at routine 20-week ultrasound. All participants kept a 4-day weighed food record following recruitment (commencement: gestational weeks 19-24). Principal component analysis was used to extract dietary patterns from 29 food groups. A Healthy Eating Index (HEI) was constructed. All women underwent an oral glucose tolerance test in weeks 23-28. One clear dietary pattern (Eigenvalue 2.4) was extracted with positive factor loadings for seafood; eggs; vegetables; fruits and berries; vegetable oils; nuts and seeds; pasta; breakfast cereals; and coffee, tea and cocoa powder, and negative factor loadings for soft drinks and French fries. This pattern was labeled a prudent dietary pattern. Explained variance was 8.2%. The prevalence of GDM was 2.3% among women of normal weight before pregnancy (n=86) and 18.3% among overweight/obese women (n=82). The prudent dietary pattern was associated with lower risk of GDM (OR: 0.54; 95% CI: 0.30, 0.98). When adjusting for age, parity, prepregnancy weight, energy intake, weekly weight gain and total metabolic equivalent of task the association remained (OR: 0.36; 95% CI: 0.14, 0.94). Similar results were found when only including overweight or obese women (OR: 0.31; 95% CI: 0.13, 0.75). Adhering to a prudent dietary pattern in pregnancy was clearly associated with lower risk of GDM, especially among women already at higher risk because of overweight/obesity before pregnancy.

The effect of thermal pre-treatment of titanium hydride (TiH2) powder in argon condition

NASA Astrophysics Data System (ADS)

Franciska P., L.; Erryani, Aprilia; Annur, Dhyah; Kartika, Ika

2018-04-01

Titanium hydride (TiH2) powders are used to enhance the foaming process in the formation of a highly porous metallic material with a cellular structure. But, the low temperature of hydrogen release is one of its problems. The present study, different thermal pre-treatment temperatures were employed to investigate the decomposition behavior of TiH2 to retard or delay a hydrogen gas release process during foaming. As a foaming agent, TiH2 was subjected to various heat treatments prior at 450 and 500°C during 2 hours in argon condition. To study the formation mechanism, the thermal behavior of titanium hydride and hydrogen release are investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The morphology of pre-treated titanium hydride powders were examined using Scanning Electron Microscope (SEM) while unsure mapping and elemental composition of the pre-treated powders processed by Energy Dispersive Spectroscopy (EDS). To study the phase formation was characterized by X-ray diffraction analysis (XRD). In accordance with the results, an increase in pre-treatment temperature of TiH2 to higher degrees are changing the process of releasing hydrogen from titanium hydride powder. DTA/TGA results showed that thermal pre-treatment TiH2 at 450°C, released the hydrogen gas at 560°C in heat treatment when foaming process. Meanwhile, thermal pre-treatment in TiH2 at 500°C, released the hydrogen gas at 670°C when foaming process. There is plenty of direct evidence for the existence of oxide layers that showed by EDS analysis obtained in SEM. As oxygen is a light element and qualitative proof shows that the higher pre-treatment temperature produces more and thicker oxygen layers on the surface of the TiH2 powder particles. It might the thickness of oxide layer are different from different pre-treatment temperatures, which leading to the differences in the decomposition temperature. But from SEM result that oxidation of the powder does not change the powder morphology. The oxidation process also confirmed by XRD result, which showed higher thermal pre-treatment TiH2, more oxide higher peak is formed. The oxide layer of TiH2 particles is responsible for the observed shift in decomposition temperature and can prepare the stable foam that stabilizes forming of cell walls and avoid their collapse at higher temperatures.

Ground-water resources and potential hydrologic effects of surface coal mining in the northern Powder River basin, southeastern Montana

USGS Publications Warehouse

Slagle, Steven E.; Lewis, Barney D.; Lee, Roger W.

1985-01-01

The shallow ground-water system in the northern Powder River Basin consists of Upper Cretaceous to Holocene aquifers overlying the Bearpaw Shale--namely, the Fox Hills Sandstone; Hell Creek, Fort Union, and Wasatch Formations; terrace deposits; and alluvium. Ground-water flow above the Bearpaw Shale can be divided into two general flow patterns. An upper flow pattern occurs in aquifers at depths of less than about 200 feet and occurs primarily as localized flow controlled by the surface topography. A lower flow pattern occurs in aquifers at depths from about 200 to 1,200 feet and exhibits a more regional flow, which is generally northward toward the Yellowstone River with significant flow toward the Powder and Tongue Rivers. The chemical quality of water in the shallow ground-water system in the study area varies widely, and most of the ground water does not meet standards for dissolved constituents in public drinking water established by the U.S. Environmental Protection Agency. Water from depths less than 200 feet generally is a sodium sulfate type having an average dissolved-solids concentration of 2,100 milligrams per liter. Sodium bicarbonate water having an average dissolved-solids concentration of 1,400 milligrams per liter is typical from aquifers in the shallow ground-water system at depths between 200 and 1,200 feet. Effects of surface coal mining on the water resources in the northern Powder River Basin are dependent on the stratigraphic location of the mine cut. Where the cut lies above the water-yielding zone, the effects will be minimal. Where the mine cut intersects a water-ielding zone, effects on water levels and flow patterns can be significant locally, but water levels and flow patterns will return to approximate premining conditions after mining ceases. Ground water in and near active and former mines may become more mineralized, owing to the placement of spoil material from the reducing zone in the unsaturated zone where the minerals are subject to oxidation. Regional effects probably will be small because of the limited areal extent of ground-water flow systems where mining is feasible. Results of digital models are presented to illustrate the effects of varying hydraulic properties on water-level changes resulting from mine dewatering. The model simulations were designed to depict maximum-drawdown situations. One simulation indicates that after 20 years of continuous dewatering of an infinite, homogeneous, isotropic aquifer that is 10 feet thick and has an initial potentiometric surface 10 feet above the top of the aquifer, water-level declines greater than 1 foot would generally be limited to within 7.5 miles of the center of the mine excavation; declines greater than 2 feet to within about 6 miles; declines greater than 5 feet to within about 3.7 miles; declines greater than 10 feet to within about 1.7 miles; and declines greater than 15 feet to within 1.2 miles.

Automated system for the on-line monitoring of powder blending processes using near-infrared spectroscopy. Part I. System development and control.

PubMed

Hailey, P A; Doherty, P; Tapsell, P; Oliver, T; Aldridge, P K

1996-03-01

An automated system for the on-line monitoring of powder blending processes is described. The system employs near-infrared (NIR) spectroscopy using fibre-optics and a graphical user interface (GUI) developed in the LabVIEW environment. The complete supervisory control and data analysis (SCADA) software controls blender and spectrophotometer operation and performs statistical spectral data analysis in real time. A data analysis routine using standard deviation is described to demonstrate an approach to the real-time determination of blend homogeneity.

Mesozoic clay diagenesis in the Appalachian Plateau

NASA Astrophysics Data System (ADS)

Boles, A.; Mulch, A.; van der Pluijm, B.

2017-12-01

Integrated investigation of authigenic clays in the Appalachian Plateau of the northeastern US Midcontinent using X-ray goniometry, Rietveld-method based illite polytype analysis, and 40Ar/39Ar geochronology yields novel insights about the structural diagenetic history of the North American sedimentary cover sequence. Texture analysis by High Resolution X-ray Texture Goniometry records the presence of a bedding-parallel diagenetic fabric, corresponding to a burial depth of 2-5 km. New development of polytype modeling using BGMN®, a quantitative X-ray powder diffraction forward modeling and whole-pattern matching program matches mineralic characteristic of illite at those depths and reduces uncertainty estimates in age analysis. Based on dating size fractions, the diagenetic age is constrained to 225-250 Ma (Triassic) by four authigenic illite samples, reflecting protracted, regional diagenesis in the area. Preliminary H isotopic analysis points to a surface-derived diagenetic fluid with δD values ranging from -48 to -72‰ (in the range of predicted Pangea meteoric fluid), with a dependence on proximity to the Appalachian Mountains that may reflect a rain shadow effect.

The precursors effects on biomimetic hydroxyapatite ceramic powders.

PubMed

Yoruç, Afife Binnaz Hazar; Aydınoğlu, Aysu

2017-06-01

In this study, effects of the starting material on chemical, physical, and biological properties of biomimetic hydroxyapatite ceramic powders (BHA) were investigated. Characterization and chemical analysis of BHA powders were performed by using XRD, FT-IR, and ICP-AES. Microstructural features such as size and morphology of the resulting BHA powders were characterized by using BET, nano particle sizer, pycnometer, and SEM. Additionally, biological properties of the BHA ceramic powders were also investigated by using water-soluble tetrazolium salts test (WST-1). According to the chemical analysis of BHA ceramic powders, chemical structures of ceramics which are prepared under different conditions and by using different starting materials show differences. Ceramic powders which are produced at 80°C are mainly composed of hydroxyapatite, dental hydroxyapatite (contain Na and Mg elements in addition to Ca), and calcium phosphate sulfide. However, these structures are altered at high temperatures such as 900°C depending on the features of starting materials and form various calcium phosphate ceramics and/or their mixtures such as Na-Mg-hydroxyapatite, hydroxyapatite, Mg-Whitlockit, and chloroapatite. In vitro cytotoxicity studies showed that amorphous ceramics produced at 80°C and ceramics containing chloroapatite structure as main or secondary phases were found to be extremely cytotoxic. Furthermore, cell culture studies showed that highly crystalline pure hydroxyapatite structures were extremely cytotoxic due to their high crystallinity values. Consequently, the current study indicates that the selection of starting materials which can be used in the production of calcium phosphate ceramics is very important. It is possible to produce calcium phosphate ceramics which have sufficient biocompatibility at physiological pH values and by using appropriate starting materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Ferromagnetic resonance studies of granular materials (abstract)

NASA Astrophysics Data System (ADS)

Rubinstein, Mark; Das, Badri; Chrisey, D. B.; Horwitz, J.; Koon, N. C.

1994-05-01

We have investigated the ferromagnetic resonance (FMR) spectra of several granular alloys displaying giant magnetoresistance (GMR). For this task, we have produced melt-spun ribbons of Fe5Co15Cu80 and Co20Cu80 by rapid quenching and thin films of Co80Cu20 by pulsed laser deposition. The salient feature of the FMR spectra is the increase of the resonance linewidth as a function of increasing annealing temperature. We have deconvoluted the FMR spectra to a single-domain powder pattern and a multidomain powder pattern. As a function of annealing temperature, the GMR of these samples attains a maximum value. Near the peak of the GMR curve, the FMR spectrum reveals that the ferromagnetic particles are half mono- and half multidomain. Since the maximum size of a single-domain particle is known, this enables us to estimate the spin diffusion length of the Cu conduction electrons. We have also demonstrated, theoretically and experimentally, that the appropriate demagnetizing field to apply to the ensemble of spherical magnetic particles that comprise our granular thin film is simply the field corresponding to the average magnetization.

Welding of Al6061and Al6082-Cu composite by friction stir processing

NASA Astrophysics Data System (ADS)

Iyer, R. B.; Dhabale, R. B.; Jatti, V. S.

2016-09-01

Present study aims at investigating the influence of process parameters on the microstructure and mechanical properties such as tensile strength and hardness of the dissimilar metal without and with copper powder. Before conducting the copper powder experiments, optimum process parameters were obtained by conducting experiments without copper powder. Taguchi's experimental L9 orthogonal design layout was used to carry out the experiments without copper powder. Threaded pin tool geometry was used for conducting the experiments. Based on the experimental results and Taguchi's analysis it was found that maximum tensile strength of 66.06 MPa was obtained at 1400 rpm spindle speed and weld speed of 20 mm/min. Maximum micro hardness (92 HV) was obtained at 1400 rpm spindle speed and weld speed of 16 mm/min. At these optimal setting of process parameters aluminium alloys were welded with the copper powder. Experimental results demonstrated that the tensile strength (96.54 MPa) and micro hardness (105 HV) of FSW was notably affected by the addition of copper powder when compared with FSW joint without copper powder. Tensile failure specimen was analysed using Scanning Electron Microscopy in order to study the failure mechanism.

Aerosolization properties, surface composition and physical state of spray-dried protein powders.

PubMed

Bosquillon, Cynthia; Rouxhet, Paul G; Ahimou, François; Simon, Denis; Culot, Christine; Préat, Véronique; Vanbever, Rita

2004-10-19

Powder aerosols made of albumin, dipalmitoylphosphatidylcholine (DPPC) and a protein stabilizer (lactose, trehalose or mannitol) were prepared by spray-drying and analyzed for aerodynamic behavior, surface composition and physical state. The powders exited a Spinhaler inhaler as particle aggregates, the size of which depending on composition, spray-drying parameters and airflow rate. However, due to low bulk powder tap density (<0.15 g/cm3), the aerodynamic size of a large fraction of aggregates remained respirable (<5 microm). Fine particle fractions ranged between 21% and 41% in an Andersen cascade impactor operated at 28.3 l/min, with mannitol and lactose providing the most cohesive and free-flowing powders, respectively. Particle surface analysis by X-ray photoelectron spectroscopy (XPS) revealed a surface enrichment with DPPC relative to albumin for powders prepared under certain spray-drying conditions. DPPC self-organized in a gel phase in the particle and no sugar or mannitol crystals were detected by X-ray diffraction. Water sorption isotherms showed that albumin protected lactose from moisture-induced crystallization. In conclusion, a proper combination of composition and spray-drying parameters allowed to obtain dry powders with elevated fine particle fractions (FPFs) and a physical environment favorable to protein stability.

The effect of native silk fibroin powder on the physical properties and biocompatibility of biomedical polyurethane membrane.

PubMed

Zhuang, Yan; Zhang, Qian; Feng, Jinqi; Wang, Na; Xu, Weilin; Yang, Hongjun

2017-04-01

Naturally derived fibers such as silk fibroin can potentially enhance the biocompatibility of currently used biomaterials. This study investigated the physical properties of native silk fibroin powder and its effect on the biocompatibility of biomedical polyurethane. Native silk fibroin powder with an average diameter of 3 µm was prepared on a purpose-built machine. A simple method of phase inversion was used to produce biomedical polyurethane/native silk fibroin powder hybrid membranes at different blend ratios by immersing a biomedical polyurethane/native silk fibroin powder solution in deionized water at room temperature. The physical properties of the membranes including morphology, hydrophilicity, roughness, porosity, and compressive modulus were characterized, and in vitro biocompatibility was evaluated by seeding the human umbilical vein endothelial cells on the top surface. Native silk fibroin powder had a concentration-dependent effect on the number and morphology of human umbilical vein endothelial cells growing on the membranes; cell number increased as native silk fibroin powder content in the biomedical polyurethane/native silk fibroin powder hybrid membrane was increased from 0% to 50%, and cell morphology changed from spindle-shaped to cobblestone-like as the native silk fibroin powder content was increased from 0% to 70%. The latter change was related to the physical characteristics of the membrane, including hydrophilicity, roughness, and mechanical properties. The in vivo biocompatibility of the native silk fibroin powder-modified biomedical polyurethane membrane was evaluated in a rat model; the histological analysis revealed no systemic toxicity. These results indicate that the biomedical polyurethane/native silk fibroin powder hybrid membrane has superior in vitro and in vivo biocompatibility relative to 100% biomedical polyurethane membranes and thus has potential applications in the fabrication of small-diameter vascular grafts and in tissue engineering.

Moisture-induced caking of beverage powders.

PubMed

Chávez Montes, Edgar; Santamaría, Nadia Ardila; Gumy, Jean-Claude; Marchal, Philippe

2011-11-01

Beverage powders can exhibit caking during storage due to high temperature and moisture conditions, leading to consumer dissatisfaction. Caking problems can be aggravated by the presence of sensitive ingredients. The caking behaviour of cocoa beverage powders, with varying amounts of a carbohydrate sensitive ingredient, as affected by climate conditions was studied in this work. Sorption isotherms of beverage powders were determined at water activities (a(w) ) ranging from 0.1 to 0.6 in a moisture sorption analyser by gravimetry and fitted to the Brunauer-Emmett-Teller (BET) or the Guggenheim-Anderson-de Boer (GAB) equation. Glass transition temperatures (T(g) ) at several a(w) were analysed by differential scanning calorimetry and fitted to the Gordon-Taylor equation. Deduced T(g) = f(a(w) ) functions helped to identify stability or caking zones. Specific experimental methods, based on the analysis of mechanical properties of powder cakes formed under compression, were used to quantify the degree of caking. Pantry tests complemented this study to put in evidence the visual perception of powder caking with increasing a(w) . The glass transition approach was useful to predict the risks of caking but was limited to products where T(g) can be measured. On the other hand, quantification of the caking degree by analysis of mechanical properties allowed estimation of the extent of degradation for each product. This work demonstrated that increasing amounts of a carbohydrate sensitive ingredient in cocoa beverages negatively affected their storage stability. Copyright © 2011 Society of Chemical Industry.

Polymer infiltration studies

NASA Technical Reports Server (NTRS)

Marchello, Joseph M.

1992-01-01

Significant progress has been made during the past three months on the preparation of carbon fiber composites using advanced polymer resins. The results are set forth in recent reports and publications, and will be presented at forthcoming national and international meetings. Current and ongoing research activities reported herein include: powdered tow ribbonizing; unitape from powdered tow; customized towpreg for textiles and ATP; and textile composite research. During the period ahead research will be directed toward further development of the new powder curtain prepregging method and on ways to customize dry powder towpreg for textile and robotic applications in aircraft part fabrication. Studies of multi-tow powder prepregging and ribbon preparation will be initiated in conjunction with continued development of prepregging technology and the various aspects of composite part fabrication using customized towpreg. Also, a major effort during the coming months will be participating in the analysis of the performance of the new solution prepregger.

Rietveld analysis of the effect of annealing atmosphere on phase evolution of nanocrystalline TiO2 powders.

PubMed

Salari, M; Rezaee, M; Chidembo, A T; Konstantinov, K; Liu, H K

2012-06-01

The structural evolution of nanocrystalline TiO2 was studied by X-ray diffraction (XRD) and the Rietveld refinement method (RRM). TiO2 powders were prepared by the sol-gel technique. Post annealing of as-synthesized powders in the temperature range from 500 degrees C to 800 degrees C under air and argon atmospheres led to the formation of TiO2 nanoparticles with mean crystallite size in the range of 37-165 nm, based on the Rietveld refinement results. It was found that the phase structure, composition, and crystallite size of the resulting particles were dependent on not only the annealing temperature, but also the annealing atmosphere. Rietveld refinement of the XRD data showed that annealing the powders under argon atmosphere promoted the polymorphic phase transformation from anatase to rutile. Field emission scanning electron microscopy (FESEM) was employed to investigate the morphology and size of the annealed powders.

Plasma-Chemical Synthesis of Oxide Powders Using Transformer-Coupled Discharge

NASA Astrophysics Data System (ADS)

M. Ulanov, I.; V. Isupov, M.; Yu Litvinsev, A.; A. Mischenko, P.

2013-04-01

An experimental investigation of transformer-coupled discharge in an Ar-O2 mixture with the addition of SiCl4, TiCl4 and ZrCl4 has been carried out under the atmospheric pressure of plasma-forming gases. Discharge power and discharge heat losses have been determined, and the dispersion and phase composition of reaction products (oxide powders) has been analyzed with SEM and X-ray diffraction analysis. Investigations reveal the formation of ultrafine oxide powders in the case of vaporized chloride (SiCl4 and TiCl4) injecting into the transformer coupled discharge. In the case of fine powder (ZrCl4) injection, full oxidation was not observed and reaction products consisted of a mixture of ZrO2 and ZrOCl2. A conclusion has been made regarding the perspectives of using transformer-coupled discharge to produce ultrafine oxide powders.

Rapid non-invasive quality control of semi-finished products for the food industry by direct injection mass spectrometry headspace analysis: the case of milk powder, whey powder and anhydrous milk fat.

PubMed

Makhoul, Salim; Yener, Sine; Khomenko, Iuliia; Capozzi, Vittorio; Cappellin, Luca; Aprea, Eugenio; Scampicchio, Matteo; Gasperi, Flavia; Biasioli, Franco

2016-09-01

In this study, we demonstrated the suitability of direct injection mass spectrometry headspace analysis for rapid non-invasive quality control of semi-finished dairy ingredients, such as skim milk powder (SMP), whole milk powder (WMP), whey powder (WP) and anhydrous milk fat (AMF), which are widely used as ingredients in the food industry. In this work, for the first time, we applied proton transfer reaction-mass spectrometry (PTR-MS) with a time-of-flight (ToF) analyzer for the rapid and non-invasive analysis of volatile compounds in different samples of SMP, WMP, WP and AMF. We selected different dairy ingredients in various concrete situations (e.g. same producer and different expiration times, different producers and same days of storage, different producers) based on their sensory evaluation. PTR-ToF-MS allowed the separation and characterization of different samples based on the volatile organic compound (VOC) profiles. Statistically significant differences in VOC content were generally coherent with differences in sensory evaluation, particularly for SMP, WMP and WP. The good separation of SMP samples from WMP samples suggested the possible application of PTR-ToF-MS to detect possible cases of adulteration of dairy ingredients for the food industry. Our findings demonstrate the efficient and rapid differentiation of dairy ingredients on the basis of the released VOCs via PTR-ToF-MS analysis and suggest this method as a versatile tool (1) for the facilitation/optimization of the selection of dairy ingredients in the food industry and (2) and for the prompt innovation in the production of dairy ingredients. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of superfine grinding on the physico-chemical, morphological and thermogravimetric properties of Lentinus edodes mushroom powders.

PubMed

Ming, Jian; Chen, Long; Hong, Hui; Li, Jinlong

2015-09-01

Lentinus edodes is an edible mushroom commonly known as shiitake, which is the second most produced and consumed edible mushroom in the world and is an important nutrient source in the human diet. To fully use L. edodes, the mushrooms are occasionally ground into powder as a flavourful and functional food additive. This study produces powders from the cap and stipe of Lentinus edodes mushrooms through superfine grinding. These powders are composed of sub-micron range particles with various size distributions. The superfine grinding process is then compared with shear pulverisation to determine the different effects on both the cap and stipe powders in terms of particle size and physico-chemical, morphological and thermogravimetric properties. When average particle size was reduced to 0.54 and 0.46 µm, respectively, the moisture and protein content, angles of repose and slide, and water holding capacity of the powders decreased to varied extents. However, soluble dietary fibre, water solubility index, and swelling capacity increased. Scanning electron microscope images suggested that the superfine grinding process effectively changed the original surface structure of the L. edodes powders. The curves of thermogravimetric analysis and those of the derivatives of thermogravimetry indicated that superfine grinding can improve the thermostability of L. edodes powders. Furthermore, superfinely ground L. edodes powders may be used as pharmaceutical or food additives in various fields. The present study suggests that superfinely ground L. edodes powders may be applied in various fields as pharmaceutical or food additives. © 2014 Society of Chemical Industry.

Sensory analysis of cosmetic powders: personal care ingredients and emulsions.

PubMed

Moussour, M; Lavarde, M; Pensé-Lhéritier, A-M; Bouton, F

2017-02-01

The powders are ingredients increasingly used in the formulation of cosmetic products for the sensory qualities they give. The objective of this study was the development of a lexicon and a referential for sensory characterization of these pure raw materials as well as formulations which contain them. Eleven expert panellists from Ecole de biologie industrielle de Cergy (France) developed a lexicon and a referential based on 12 powders of different chemical natures. The selected attributes were then used for performing a quantitative descriptive profile of two powders and an emulsion containing or not one of these two powders. A lexicon has been established through a consensus approach of the panel. It contains seven attributes that allow the evaluation of the powders in four phases: the appearance, the pickup, the application and the after-feel. This lexicon contains definitions and assessment protocols and provides references products. The quantitative descriptive profile of two powders of the same chemical nature, but different in physical quality showed significant differences in sensory level between products. These same attributes used to evaluate an emulsion containing the powder or not allowed to prove the contribution of these raw materials on the sensory specificities of the emulsion. The lexicon developed in this study can be used for assessment of other powders but also to define the quantities necessary to put in the formulation to meet the sensory characteristics of these raw materials powder. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Penetration depth measurement of near-infrared hyperspectral imaging light for milk powder

USDA-ARS?s Scientific Manuscript database

The increasingly common application of near-infrared (NIR) hyperspectral imaging technique to the analysis of food powders has led to the need for optical characterization of samples. This study was aimed at exploring the feasibility of quantifying penetration depth of NIR hyperspectral imaging ligh...

Features of the incorporation of single and double based powders within emulsion explosives

NASA Astrophysics Data System (ADS)

Ribeiro, J. B.; Mendes, R.; Tavares, B.; Louro, C.

2014-05-01

In this work, features of the thermal and detonation behaviour of compositions resulting from the mixture of single and double based powders within ammonium nitrate based emulsion explosives are shown. Those features are portrayed through results of thermodynamic-equilibrium calculations of the detonation velocity, the chemical compatibility assessment through differential thermal analysis [DTA] and thermo gravimetric analysis [TGA], the experimental determination of the detonation velocity and a comparative evaluation of the shock sensitivity using a modified version of the "gap-test". DTA/TGA results for the compositions and for the individual components overlap until the beginning of the thermal decomposition which is an indication of the absence of formation of any new chemical species and so of the compatibility of the components of the compositions. After the beginning of the thermal decomposition it can be seen that the rate of mass loss is much higher for the compositions with powder than for the one with sole emulsion explosive. Both, theoretical and experimental, values of the detonation velocity have been shown to be higher for the powdered compositions than for the sole emulsion explosive. Shock sensitivity assessments have ended-up with a slightly bigger sensitivity for the compositions with double based powder when compared to the single based compositions or to the sole emulsion.

Environmental, Human Health and Socio-Economic Effects of Cement Powders: The Multicriteria Analysis as Decisional Methodology

PubMed Central

Moretti, Laura; Di Mascio, Paola; Bellagamba, Simona

2017-01-01

The attention to sustainability-related issues has grown fast in recent decades. The experience gained with these themes reveals the importance of considering this topic in the construction industry, which represents an important sector throughout the world. This work consists on conducting a multicriteria analysis of four cement powders, with the objective of calculating and analysing the environmental, human health and socio-economic effects of their production processes. The economic, technical, environmental and safety performances of the examined powders result from official, both internal and public, documents prepared by the producers. The Analytic Hierarchy Process permitted to consider several indicators (i.e., environmental, human health related and socio-economic parameters) and to conduct comprehensive and unbiased analyses which gave the best, most sustainable cement powder. As assumed in this study, the contribution of each considered parameter to the overall sustainability has a different incidence, therefore the procedure could be used to support on-going sustainability efforts under different conditions. The results also prove that it is not appropriate to regard only one parameter to identify the ‘best’ cement powder, but several impact categories should be considered and analysed if there is an interest for pursuing different, often conflicting interests. PMID:28621754

Development of a Novel Ni-Fe-Cr-B-Si Interlayer Material for Transient Liquid Phase Bonding of Inconel 718

NASA Astrophysics Data System (ADS)

Tarai, U. K.; Robi, P. S.; Pal, Sukhomay

2018-04-01

A Ni-Cr-Fe-Si-B based interlayer material was developed by mechanical alloying (MA) process in a high-energy planetary ball mill. Equiaxed alloy powders of size 12 µm was obtained after milling for 50 hours. X-ray diffraction analysis of the milled powder revealed that milling of elemental powders initially resulted in microcrystalline alloy powder having face centered cubic structure, which on subsequent milling resulted in nano-crystallice alloy powder with a crystallite size of 3.2 nm. XRD analysis also reveals formation of metastable eutectic alloys resulting in lowering of the melting point of the interlayer material to 1025 °C. IN 718 superalloy samples were joined at 1050°C using the developed interlayer. A homogeneous joint was formed by the newly developed interlayer material. Three different zones were observed at the bond (i) isothermally solidified zone, (ii) diffusion affected zone and (iii) unaffected base metal. In the diffusion-affected zone, boron was present at the grain boundaries of Ni γ matrix in bulky metal borides form. The diffusion of boron from interlayer material into the base material was mechanism of isothermal solidification and bond formation in transient liquid phase bonding of IN 718.

Reproducing Kernel Particle Method in Plasticity of Pressure-Sensitive Material with Reference to Powder Forming Process

NASA Astrophysics Data System (ADS)

Khoei, A. R.; Samimi, M.; Azami, A. R.

2007-02-01

In this paper, an application of the reproducing kernel particle method (RKPM) is presented in plasticity behavior of pressure-sensitive material. The RKPM technique is implemented in large deformation analysis of powder compaction process. The RKPM shape function and its derivatives are constructed by imposing the consistency conditions. The essential boundary conditions are enforced by the use of the penalty approach. The support of the RKPM shape function covers the same set of particles during powder compaction, hence no instability is encountered in the large deformation computation. A double-surface plasticity model is developed in numerical simulation of pressure-sensitive material. The plasticity model includes a failure surface and an elliptical cap, which closes the open space between the failure surface and hydrostatic axis. The moving cap expands in the stress space according to a specified hardening rule. The cap model is presented within the framework of large deformation RKPM analysis in order to predict the non-uniform relative density distribution during powder die pressing. Numerical computations are performed to demonstrate the applicability of the algorithm in modeling of powder forming processes and the results are compared to those obtained from finite element simulation to demonstrate the accuracy of the proposed model.

Process for Making Ceramic Mold

NASA Technical Reports Server (NTRS)

Buck, Gregory M. (Inventor); Vasquez, Peter (Inventor)

2001-01-01

An improved process for slip casting molds that can be more economically automated and that also exhibits greater dimensional stability is disclosed. The process involves subjecting an investment pattern, preferably made from wax, to successive cycles of wet-dipping in a slurry of colloidal, silica-based binder and dry powder-coating, or stuccoing with plaster of Paris or calcium sulfate mixtures to produce a multi-layer shell over the pattern. The invention as claimed entails applying a primary and a secondary coating to the investment pattern. At least two wet-dipping on in a primary slurry and dry-stuccoing cycles provide the primary coating, and an additional two wet-dippings and dry-stuccoing cycles provide the secondary, or back-up, coating. The primary and secondary coatings produce a multi-layered shell pattern. The multi-layered shell pattern is placed in a furnace first to cure and harden, and then to vaporize the investment pattern, leaving a detailed, high precision shell mold.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pratapa, S.; Susanti, L.; Insany, Y. A. S.

Simple coprecipitation method has been used to produce nanoparticles of MgO (magnesia), MgO{center_dot}Al{sub 2}O{sub 3}(spinel), Y{sub 2}O{sub 3}(yttria) and Fe{sub 3}O{sub 4}(ferrite). The raw materials were, in respective, magnesium powder, magnesium and aluminium powders, ytrria powder, and natural sand. The coprecipitation included the use of suitable acid and base to dissolve the powders or sand and to produce precipitates, as well as the use of water to wash and purify the precipitates, and drying at relatively low temperatures, namely lower than 100 deg. C, followed by heating at 450 deg. C, 750 deg. C, 600 deg. C and 200 deg.more » C to produce magnesia, spinel, yttria and ferrite nanopowders, respectively. X-ray diffractometry was used to characterise the purity and nanocrystallinity of the final powders. It was found qualitatively that the powders were of high purity. Further line-broadening analysis using single-line and Rietveld-based softwares was performed to reveal the nanocrystallinity of the powders. Different line breadth values were found for the powders, indicating different crystallite sizes. It was also found that, particularly for spinel and yttria, the diffraction peaks exhibited 'longer' tails, indicating broader crystallite size distribution. The average crystallite size for the powders ranged from 3 to 70 nm. The results could then be used as 'fingerprints' for nanocrystallinity using x-ray diffractometry. The XRD crystallite sizes for yttria and ferrite nanocrystals are in fair agreement with their counterparts from electron microscopy observation.« less

Uniform-droplet spray forming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blue, C.A.; Sikka, V.K.; Chun, Jung-Hoon

1997-04-01

The uniform-droplet process is a new method of liquid-metal atomization that results in single droplets that can be used to produce mono-size powders or sprayed-on to substrates to produce near-net shapes with tailored microstructure. The mono-sized powder-production capability of the uniform-droplet process also has the potential of permitting engineered powder blends to produce components of controlled porosity. Metal and alloy powders are commercially produced by at least three different methods: gas atomization, water atomization, and rotating disk. All three methods produce powders of a broad range in size with a very small yield of fine powders with single-sized droplets thatmore » can be used to produce mono-size powders or sprayed-on substrates to produce near-net shapes with tailored microstructures. The economical analysis has shown the process to have the potential of reducing capital cost by 50% and operating cost by 37.5% when applied to powder making. For the spray-forming process, a 25% savings is expected in both the capital and operating costs. The project is jointly carried out at Massachusetts Institute of Technology (MIT), Tuffs University, and Oak Ridge National Laboratory (ORNL). Preliminary interactions with both finished parts and powder producers have shown a strong interest in the uniform-droplet process. Systematic studies are being conducted to optimize the process parameters, understand the solidification of droplets and spray deposits, and develop a uniform-droplet-system (UDS) apparatus appropriate for processing engineering alloys.« less

Use of an Ultrasonic/Sonic Driller/Corer to Obtain Sample Powder for CHEMIN, a Combined XRD/XRF Instrument

NASA Technical Reports Server (NTRS)

Chipera, S. J.; Bish, D. L.; Vaniman, D. T.; Sherrit, S.; Bar-Cohen, Y.; Sarrazin, P.; Blake, D. F.

2003-01-01

A miniature CHEMIN XRD/XRF (X-Ray Diffraction/X-Ray Fluourescence) instrument is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed in order to enable XRD analysis on an extraterrestrial body is how best to obtain a representative sample powder for analysis. For XRD powder diffraction analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a 2-dimensional detector as used in the CHEMIN instrument will produce good results with poorly prepared powders, the quality of the data will improve if the sample is fine-grained and randomly oriented. An Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL is an effective mechanism of sampling rock to produce cores and powdered cuttings. It requires low axial load (< 5N) and thus offers significant advantages for operation from lightweight platforms and in low gravity environments. The USDC is lightweight (<0.5kg), and can be driven at low power (<5W) using duty cycling. It consists of an actuator with a piezoelectric stack, ultrasonic horn, free-mass, and drill bit. The stack is driven with a 20 kHz AC voltage at resonance. The strain generated by the piezoelectric is amplified by the horn by a factor of up to 10 times the displacement amplitude. The tip impacts the free-mass and drives it into the drill bit in a hammering action. The free-mass rebounds to interact with the horn tip leading to a cyclic rebound at frequencies in the range of 60-1000 Hz. It does not require lubricants, drilling fluid or bit sharpening and it has the potential to operate at high and low temperatures using a suitable choice of piezoelectric material. To assess whether the powder from an ultrasonic drill would be adequate for analyses by an XRD/XRF spectrometer such as CHEMIN, powders obtained from the JPL ultrasonic drill were analyzed and the results were compared to carefully prepared powders obtained using a laboratory bench scale Retsch mill.

Identification of a gamma-irradiated ingredient (garlic powder) in Korean barbeque sauce by thermoluminescence analysis.

PubMed

Ahn, Jae-Jun; Akram, Kashif; Lee, Jeongeun; Kim, Kyong-Su; Kwon, Joong-Ho

2012-04-01

Thermoluminescence (TL) analysis was applied to identify gamma-irradiated garlic powder in Korean barbeque sauce before and after pasteurization (85 °C, 30 min), when blended in different ratios (1%, 3%, and 5%). The sauce sample with nonirradiated garlic powder gave a background glow curve. However, the sample blended with irradiated ingredient (1 and 10 kGy) showed typical TL glow curves at temperatures of 150 to 200 °C. The identification properties of sauce samples were more influenced by blending ratios than by irradiation doses, showing that 3% and 5% added samples produced glow curves at 150 to 250 °C. After pasteurization of the samples containing the irradiated ingredient, TL glow intensity decreased but did not change its shape or temperature range. As a result, the pasteurization of Barbeque sauces containing irradiated ingredients had reduced TL glow intensity, but the shape and temperature range of glow curve were still able to provide information required for confirming irradiation treatment. To monitor the irradiated food in international market, thermoluminescence (TL) analysis is considered most promising identification technique because of its sensitivity and long-term stability. In this study the applicability of TL analysis to detect an irradiated ingredient (garlic powder) added in low quantity to a food matrix (sauce) was investigated. The effect of processing (pasteurization) on TL results was also evaluated. © 2012 Institute of Food Technologists®

Flake like V{sub 2}O{sub 5} nanoparticles for ethanol sensing at room temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chitra, M.; Uthayarani, K.; Rajasekaran, N.

2016-05-23

The versatile redox property of vanadium oxide explores it in various applications like catalysis, electrochromism, electrochemistry, energy storage, sensors, microelectronics, batteries etc., In this present work, vanadium oxide was prepared via hydrothermal route followed by calcination. The structural and lattice parameters were analysed from the powder X-ray diffraction (XRD) pattern. The morphology and the composition of the sample were obtained from Field emission Scanning electron microscopic (FeSEM) and Energy Dispersive X-ray (EDAX) Spectrometric analysis respectively. The sensitivity, response – recovery time of the sample towards ethanol (0 ppm – 300 ppm) sensing at room temperature was measured and the present investigation onmore » vanadium oxide nanoparticles over the flakes shows better sensitivity (30%) at room temperature.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frølich, S.; Leemreize, H.; Jakus, A.

A model sample consisting of two different hydroxyapatite (hAp) powders was used as a bone phantom to investigate the extent to which X-ray diffraction tomography could map differences in hAp lattice constants and crystallite size. The diffraction data were collected at beamline 1-ID, the Advanced Photon Source, using monochromatic 65 keV X-radiation, a 25 × 25 µm pinhole beam and translation/rotation data collection. The diffraction pattern was reconstructed for each volume element (voxel) in the sample, and Rietveld refinement was used to determine the hAp lattice constants. The crystallite size for each voxel was also determined from the 00.2 hApmore » diffraction peak width. The results clearly show that differences between hAp powders could be measured with diffraction tomography.« less

The structural properties of barium cobalt hexaferrite powder prepared by a simple heat treatment method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chauhan, Chetna, E-mail: chetna.chauhan@nirmauni.ac.in; Jotania, Rajshree, E-mail: rbjotania@gmail.com

2016-05-06

The W-type barium hexaferrite was prepared using a simple heat treatment method. The precursor was calcinated at 650°C for 3 hours and then slowly cooled to room temperature in order to obtain barium cobalt hexaferrite powder. The prepared powder was characterised by different experimental techniques like XRD, FTIR and SEM. The X-ray diffractogram of the sample shows W-and M phases. The particle size calculated by Debye Scherrer formula. The FTIR spectra of the sample was taken at room temperature by using KBr pallet method which confirms the formation of hexaferrite phase. The morphological study on the hexaferrite powder was carriedmore » out by SEM analysis.« less

The Effect of Time, Temperature and Composition on Boron Carbide Synthesis by Sol-gel Method

NASA Astrophysics Data System (ADS)

Hadian, A. M.; Bigdeloo, J. A.

2008-02-01

To minimize free carbon residue in the boron carbide (B4C) powder, a modified sol-gel process is performed where the starting materials as boric acid and citric acid compositions are adjusted. Because of boron loss in the form of B2O2(g) during the reduction reaction of the stoichiometric starting composition, the final B4C powders contain carbon residues. Thus, an excess H3BO3 is used in the reaction to compensate the loss and to obtain stoichiometric powders. Parameters of production have been determined using x-ray diffraction analysis and particle size analyses. The synthesized B4C powder using an excess boric acid composition shows no trace of carbon.

Real-time powder diffraction studies of energy materials under non-equilibrium conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Vanessa K.; Auckett, Josie E.; Pang, Wei-Kong

Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage ofmore » energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function.« less

Preparation of SS316L MIM feedstock with biopolymer as a binder

NASA Astrophysics Data System (ADS)

Abdullah, A. A.; Norita, H.; Azlina, H. N.; Sulong, A. B.; Mas'ood, N. N.

2018-01-01

This paper focus on feedstock preparation for SS316L metal injection molding (MIM) part. The primary step of feedstock preparation, critical powder loading determined by two method; maximum filled volume calculation model and torque analysis. The critical powder loading determined by calculation was 70 vol% to 77 vol% while for experimental approaches shows the value of 75 vol%. The feedstock was prepared by mixing SS316L powder and polymer binder with ratio 70:30 at 175 °C with speed of 50 rpm. The feedstock was analyzed by thermogravimetric analysis (TGA) and Scanning electron microscope (SEM). The composition for the feedstock after preparation step was confirmed by TGA. It was found that the prepared feedstock component was compatible to each other and composition is maintain along the mixing step.

Real-time powder diffraction studies of energy materials under non-equilibrium conditions

PubMed Central

Peterson, Vanessa K.; Auckett, Josie E.; Pang, Wei-Kong

2017-01-01

Energy materials form the central part of energy devices. An essential part of their function is the ability to reversibly host charge or energy carriers, and analysis of their phase composition and structure in real time under non-equilibrium conditions is mandatory for a full understanding of their atomic-scale functional mechanism. Real-time powder diffraction is increasingly being applied for this purpose, forming a critical step in the strategic chemical engineering of materials with improved behaviour. This topical review gives examples of real-time analysis using powder diffraction of rechargeable battery electrodes and porous sorbent materials used for the separation and storage of energy-relevant gases to demonstrate advances in the insights which can be gained into their atomic-scale function. PMID:28989711

L-Leucine as an excipient against moisture on in vitro aerosolization performances of highly hygroscopic spray-dried powders.

PubMed

Li, Liang; Sun, Siping; Parumasivam, Thaigarajan; Denman, John A; Gengenbach, Thomas; Tang, Patricia; Mao, Shirui; Chan, Hak-Kim

2016-05-01

L-Leucine (LL) has been widely used to enhance the dispersion performance of powders for inhalation. LL can also protect powders against moisture, but this effect is much less studied. The aim of this study was to investigate whether LL could prevent moisture-induced deterioration in in vitro aerosolization performances of highly hygroscopic spray-dried powders. Disodium cromoglycate (DSCG) was chosen as a model drug and different amounts of LL (2-40% w/w) were added to the formulation, with the aim to explore the relationship between powder dispersion, moisture protection and physicochemical properties of the powders. The powder formulations were prepared by spray drying of aqueous solutions containing known concentrations of DSCG and LL. The particle sizes were measured by laser diffraction. The physicochemical properties of fine particles were characterized by X-ray powder diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic vapor sorption (DVS). The surface morphology and chemistry of fine particles were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). In vitro aerosolization performances were evaluated by a next generation impactor (NGI) after the powders were stored at 60% or 75% relative humidity (RH), and 25°C for 24h. Spray-dried (SD) DSCG powders were amorphous and absorbed 30-45% (w/w) water at 70-80% RH, resulting in deterioration in the aerosolization performance of the powders. LL did not decrease the water uptake of DSCG powders, but it could significantly reduce the effect of moisture on aerosolization performances. This is due to enrichment of crystalline LL on the surface of the composite particles. The effect was directly related to the percentage of LL coverage on the surface of particles. Formulations having 61-73% (molar percent) of LL on the particle surface (which correspond to 10-20% (w/w) of LL in the bulk powders) could minimize moisture-induced deterioration in the aerosol performance. In conclusion, particle surface coverage of LL can offer short-term protection against moisture on dispersion of hygroscopic powders. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of nano-forsterite powder by making use of natural silica sand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nurbaiti, Upik, E-mail: upik-nurbaiti@mail.unnes.ac.id; Department of Physics, Faculty of Mathematics and Natural Sciences Semarang State University Jl. Raya Sekaran GunungPati, Semarang 50221; Suud, Fikriyatul Azizah

2016-02-08

Nano-forsterite powder with natural silica sand and magnesium powder as the raw materials have been succesfully synthesized. The silica sand was purified followed by a coprecipitation process to obtain colloidal silica. The magnesium powder was dissolved in a chloric acid solution to obtain MgCl{sub 2} solution. The nanoforsterite powder was synthesised using a sol-gel method which included the mixing the colloidal silica and the MgCl{sub 2} solution with various aging and filtering processes. The samples were dried at 100 °C using a hot plate and then the dried powders were calcinated at 900 °C for 2 hours. The samples weremore » characetised for their elements and phase compositions using X-ray Flourescence (XRF) and X-ray Diffraction (XRD) methods, respectively. The diffraction data were qualitatively analyzed using Match!2 software and quantitatively using Rietica software. The crystallite size was verified using Transmission Electron Microscopy (TEM). Results of XRD data analysis showed that the forsterite content reached up to 90.5% wt. The TEM average crystallite size was approximately 53(6) nm.« less

A material-sparing method for simultaneous determination of true density and powder compaction properties--aspartame as an example.

PubMed

Sun, Changquan Calvin

2006-12-01

True density results for a batch of commercial aspartame are highly variable when helium pycnometry is used. Alternatively, the true density of the problematic aspartame lot was obtained by fitting tablet density versus pressure data. The fitted true density was in excellent agreement with that predicted from single crystal structure. Tablet porosity was calculated from the true density and tablet apparent density. After making the necessary measurements for calculating tablet apparent density, the breaking force of each intact tablet was measured and tensile strength was calculated. With the knowledge of compaction pressure, tablet porosity and tensile strength, powder compaction properties were characterized using tabletability (tensile strength versus pressure), compactibility (tensile strength versus porosity), compressibility (porosity versus pressure) and Heckel analysis. Thus, a wealth of additional information on the compaction properties of the powder was obtained through little added work. A total of approximately 4 g of powder was used in this study. Depending on the size of tablet tooling, tablet thickness and true density, 2-10 g of powder would be sufficient for characterizing most pharmaceutical powders.

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

PubMed

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

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.

Porous Nb-Ti based alloy produced from plasma spheroidized powder

NASA Astrophysics Data System (ADS)

Li, Qijun; Zhang, Lin; Wei, Dongbin; Ren, Shubin; Qu, Xuanhui

Spherical Nb-Ti based alloy powder was prepared by the combination of plasma spheroidization and mechanical alloying. Phase constituents, microstructure and surface state of the powder, and pore characteristics of the resulting porous alloy were investigated. The results show that the undissolved W and V in the mechanically alloyed powder is fully alloyed after spheroidization, and single β phase is achieved. Particle size of the spheroidized powder is in the range of 20-110 μm. With the decrease of particle size, a transformation from typical dendrite solidification structure to fine cell microstructure occurs. The surface of the spheroidized powder is coated by a layer of oxides consisting mainly of TiO2 and Nb2O5. Probabilities of sinter-neck formation and particle coalescence increases with increasing sintering temperature. Porous skeleton with relatively homogeneous pore distribution and open pore channel is formed after vacuum sintering at 1700 °C, and the porosity is 32%. The sintering kinetic analysis indicates that grain boundary diffusion is the primary mass transport mechanism during sintering process.

Ab initio random structure searching of organic molecular solids: assessment and validation against experimental data† †Electronic supplementary information (ESI) available: Results of similarity analysis between the 11 structures of lowest energy obtained in the AIRSS calculations and the reported structures of form III and form IV of m-ABA; unit cell parameters and volumes for all structures considered; comparison of 2θ values derived from the unit cell parameters of different structural models representing form III of m-ABA; Le Bail fitting of the experimental powder XRD pattern of form IV of m-ABA recorded at 70 K using, as the initial structural model, the reported crystal structure following geometry optimization; table of calculated (GIPAW) absolute isotropic NMR shieldings; simulated powder XRD data for the considered structures after precise geometry optimization; experimental 1H MAS NMR spectra of forms III and IV. (pdf) The calculated and experimental data for this study are provided as a supporting dataset from WRAP, the Warwick Research Archive Portal at http://wrap.warwick.ac.uk/91884. See DOI: 10.1039/c7cp04186a

PubMed Central

Zilka, Miri; Dudenko, Dmytro V.; Hughes, Colan E.; Williams, P. Andrew; Sturniolo, Simone; Franks, W. Trent; Pickard, Chris J.

2017-01-01

This paper explores the capability of using the DFT-D ab initio random structure searching (AIRSS) method to generate crystal structures of organic molecular materials, focusing on a system (m-aminobenzoic acid; m-ABA) that is known from experimental studies to exhibit abundant polymorphism. Within the structural constraints selected for the AIRSS calculations (specifically, centrosymmetric structures with Z = 4 for zwitterionic m-ABA molecules), the method is shown to successfully generate the two known polymorphs of m-ABA (form III and form IV) that have these structural features. We highlight various issues that are encountered in comparing crystal structures generated by AIRSS to experimental powder X-ray diffraction (XRD) data and solid-state magic-angle spinning (MAS) NMR data, demonstrating successful fitting for some of the lowest energy structures from the AIRSS calculations against experimental low-temperature powder XRD data for known polymorphs of m-ABA, and showing that comparison of computed and experimental solid-state NMR parameters allows different hydrogen-bonding motifs to be discriminated. PMID:28944393

The spectroscopic detection of drugs of abuse in fingerprints after development with powders and recovery with adhesive lifters

NASA Astrophysics Data System (ADS)

West, Matthew J.; Went, Michael J.

2009-01-01

The application of powders to fingerprints has long been established as an effective and reliable method for developing latent fingerprints. Fingerprints developed in situ at a crime scene routinely undergo lifting with specialist tapes and are then stored in evidence bags to allow secure transit and also to preserve the chain of evidence. In a previous study we have shown that exogenous material within a fingerprint can be detected using Raman spectroscopy following development with powders and lifting with adhesive tapes. Other reports have detailed the use of Raman spectroscopy to the detection of drugs of abuse in latent fingerprints including cyanoacrylate-fumed fingerprints. This study involves the application of Raman spectroscopy for the analysis of drugs of abuse in latent fingerprints for fingerprints that had been treated with powders and also subsequently lifted with adhesive tapes. Samples of seized ecstasy, cocaine, ketamine and amphetamine were supplied by East Sussex Police and by the TICTAC unit at St. Georges Hospital Tooting. Contaminated fingerprints were deposited on clean glass slides. The application of aluminium or iron based powders to contaminated fingerprints did not interfere with the Raman spectra obtained for the contaminants. Contaminated fingerprints developed with powders and then lifted with lifting tapes were also examined. The combination of these two techniques did not interfere with the successful analysis. The lifting process was repeated using hinge lifters. As the hinge lifters exhibited strong Raman bands the spectroscopic analysis was more complex and an increase in the number of exposures to the detector allowed for improved clarification. Spectral subtraction was performed to remove peaks due to the hinge lifters using OMNIC software. Raman spectra of developed and lifted fingerprints recorded through evidence bags were obtained and it was found that the detection process was not compromised. Although the application of powders did not interfere with the detection process the time taken to locate the contaminant was increased due to the physical presence of more material within the fingerprint.

The spectroscopic detection of drugs of abuse in fingerprints after development with powders and recovery with adhesive lifters.

PubMed

West, Matthew J; Went, Michael J

2009-01-01

The application of powders to fingerprints has long been established as an effective and reliable method for developing latent fingerprints. Fingerprints developed in situ at a crime scene routinely undergo lifting with specialist tapes and are then stored in evidence bags to allow secure transit and also to preserve the chain of evidence. In a previous study we have shown that exogenous material within a fingerprint can be detected using Raman spectroscopy following development with powders and lifting with adhesive tapes. Other reports have detailed the use of Raman spectroscopy to the detection of drugs of abuse in latent fingerprints including cyanoacrylate-fumed fingerprints. This study involves the application of Raman spectroscopy for the analysis of drugs of abuse in latent fingerprints for fingerprints that had been treated with powders and also subsequently lifted with adhesive tapes. Samples of seized ecstasy, cocaine, ketamine and amphetamine were supplied by East Sussex Police and by the TICTAC unit at St. Georges Hospital Tooting. Contaminated fingerprints were deposited on clean glass slides. The application of aluminium or iron based powders to contaminated fingerprints did not interfere with the Raman spectra obtained for the contaminants. Contaminated fingerprints developed with powders and then lifted with lifting tapes were also examined. The combination of these two techniques did not interfere with the successful analysis. The lifting process was repeated using hinge lifters. As the hinge lifters exhibited strong Raman bands the spectroscopic analysis was more complex and an increase in the number of exposures to the detector allowed for improved clarification. Spectral subtraction was performed to remove peaks due to the hinge lifters using OMNIC software. Raman spectra of developed and lifted fingerprints recorded through evidence bags were obtained and it was found that the detection process was not compromised. Although the application of powders did not interfere with the detection process the time taken to locate the contaminant was increased due to the physical presence of more material within the fingerprint.

Heat-Stable Dry Powder Oxytocin Formulations for Delivery by Oral Inhalation.

PubMed

Fabio, Karine; Curley, Kieran; Guarneri, Joseph; Adamo, Benoit; Laurenzi, Brendan; Grant, Marshall; Offord, Robin; Kraft, Kelly; Leone-Bay, Andrea

2015-12-01

In this work, heat stable dry powders of oxytocin (OT) suitable for delivery by oral inhalation were prepared. The OT dry powders were prepared by spray drying using excipients chosen to promote OT stability including trehalose, isoleucine, polyvinylpyrrolidone, citrate (sodium citrate and citric acid), and zinc salts (zinc chloride and zinc citrate). Characterization by laser diffraction indicated that the OT dry powders had a median particle size of 2 μm, making them suitable for delivery by inhalation. Aerodynamic performance upon discharge from proprietary dry powder inhalers was evaluated by Andersen cascade impaction (ACI) and in an anatomically correct airway (ACA) model, and confirmed that the powders had excellent aerodynamic performance, with respirable fractions up to 77% (ACI, 30 L/min). Physicochemical characterization demonstrated that the powders were amorphous (X-ray diffraction) with high glass transition temperature (modulated differential scanning calorimetry, MDSC), suggesting the potential for stabilization of the OT in a glassy amorphous matrix. OT assay and impurity profile were conducted by reverse phase HPLC and liquid chromatography-mass spectrometry (LC-MS) after storage up to 32 weeks at 40°C/75%RH. Analysis demonstrated that OT dry powders containing a mixture of citrate and zinc salts retained more than 90% of initial assay after 32 weeks storage and showed significant reduction in dimers and trisulfide formation (up to threefold reduction compared to control).

The filling of powdered herbs into two-piece hard capsules using hydrogenated cotton seed oil as lubricant.

PubMed

Aling, Joanna; Podczeck, Fridrun

2012-11-20

The aim of this work was to investigate the plug formation and filling properties of powdered herbal leaves using hydrogenated cotton seed oil as an alternative lubricant. In a first step, unlubricated and lubricated herbal powders were studied on a small scale using a plug simulator, and low-force compression physics and parameterization techniques were used to narrow down the range in which the optimum amount of lubricant required would be found. In a second step these results were complemented with investigations into the flow properties of the powders based on packing (tapping) experiments to establish the final optimum lubricant concentration. Finally, capsule filling of the optimum formulations was undertaken using an instrumented tamp filling machine. This work has shown that hydrogenated cotton seed oil can be used advantageously for the lubrication of herbal leaf powders. Stickiness as observed with magnesium stearate did not occur, and the optimum lubricant concentration was found to be less than that required for magnesium stearate. In this work, lubricant concentrations of 1% or less hydrogenated cotton seed oil were required to fill herbal powders into capsules on the instrumented tamp-filling machine. It was found that in principle all powders could be filled successfully, but that for some powders the use of higher compression settings was disadvantageous. Relationships between the particle size distributions of the powders, their flow and consolidation as well as their filling properties could be identified by multivariate statistical analysis. The work has demonstrated that a combination of the identification of plug formation and powder flow properties is helpful in establishing the optimum lubricant concentration required using a small quantity of powder and a powder plug simulator. On an automated tamp-filling machine, these optimum formulations produced satisfactory capsules in terms of coefficient of fill weight variability and capsule weight. Copyright © 2012 Elsevier B.V. All rights reserved.

Protective effect of Acticoa powder, a cocoa polyphenolic extract, on prostate carcinogenesis in Wistar-Unilever rats.

PubMed

Bisson, Jean-François; Guardia-Llorens, Maria-Alba; Hidalgo, Sophie; Rozan, Pascale; Messaoudi, Michaël

2008-02-01

The effects of Acticoa powder on prostate carcinogenesis were investigated using the N-methylnitrosourea and testosterone propionate prostate tumor model. Sixty male Wistar-Unilever rats were randomly divided in four groups of 15 rats: one control group not induced but treated with vehicle (not induced+vehicle) and three chemo-induced groups. Two weeks before prostate tumor induction and then throughout the experiment, chemo-induced rats were orally treated with Acticoa powder at 24 (chemo-induced+Acticoa powder24) or 48 (chemo-induced+Acticoa powder48) mg/kg or with vehicle (chemo-induced+vehicle), daily from Monday to Friday. Survival, body weight, food and water consumption were recorded throughout the experiment. Six rats per group were randomly killed 9 months after the prostate tumor induction for histopathological analysis of prostates. A reduction in the incidence of prostate tumors was observed for the chemo-induced+Acticoa powder48-treated group in comparison with the chemo-induced+vehicle-treated group and no tumors were observed in the chemo-induced+Acticoa powder24-treated group as in the not induced+vehicle-treated group after 9 months. The nine remaining rats per group were maintained in a long-term survival study. The life span of the chemo-induced+Acticoa powder24-treated group was significantly increased in comparison with the chemo-induced+Acticoa powder48 and the chemo-induced+vehicle-treated groups, close to the one of the not induced+vehicle-treated group. A significant reduction in the incidence of prostate tumors was also observed for the chemo-induced+Acticoa powder24 and chemo-induced+Acticoa powder48-treated groups in comparison with the chemo-induced+vehicle-treated group. In conclusion, Acticoa powder at 24 mg/kg protected rats from prostate carcinogenesis when chronically given before the initiation and promotion phases of induction.

The interactions of dietary tomato powder and soy germ on prostate carcinogenesis in the TRAMP model

PubMed Central

Zuniga, Krystle E.; Clinton, Steven K; Erdman, John W.

2013-01-01

The interactions between bioactive rich food components within a complex human diet for the inhibition of prostate carcinogenesis (PCa) are largely unknown and difficult to quantify in humans. Tomato and soy products have each shown anti-PCa activity in laboratory studies. The objective of this study was to determine the efficacy of dietary tomato and soy germ, alone and in combination, for the inhibition of prostate carcinogenesis in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. At 4 weeks of age, male C57BL/6 × FVB TRAMP mice (n=119) were randomized to consume: AIN-93G control, 10% whole tomato powder (TP), 2% soy germ powder (SG) or 10% tomato powder with 2% soy germ powder (TP+SG) for 14 weeks. 100% of mice fed the control diet had PCa, while PCa incidence was significantly lower in mice consuming TP (61%, p<0.001), SG (66%, p<0.001) and TP+SG (45%, p<0.001). Although the protection offered by the combination of TP and SG was not synergistic, it was the most effective intervention. TP, SG and TP+SG increased apoptotic index (AI) and modestly reduced the proliferative index (PI) in the prostate epithelium of TRAMP mice exhibiting primarily prostatic intraepithelial neoplasia. The dramatic reduction in the PI/AI ratio by the dietary interventions suggests that the control mice experience a stronger stimulus for malignant progression in the prostate microenvironment. Maximally effective and safe strategies for PCa prevention may result from optimizing combinations of nutrients and bioactives through an orchestration of dietary patterns. PMID:23592738

The simultaneous isolation of human pituitary hormones. I. Human growth hormone.

PubMed

Simionescu, L; Dimitriu, V; Zamfir-Grigorescu, D; Aman, E; Terbancea, M

1982-01-01

The main purposes of the present work are: a. the preparation of "clinical grade" human growth hormone (hGH), its physico-chemical analysis and the improvement of its solubility for clinical purposes; b. the development of a method for the isolation of high-purity hGH using frozen pituitaries. Nine batches of 20 g acetone powder were processed resulting in 4940 mg of "clinical grade" hGH. Samples of these batches randomly selected were analysed by Sephadex G-100 chromatography and by disc and preparative polyacrylamide gel electrophoresis (PAGE). Lyophilised hGH, soluble in NaCl 0.15 M was prepared and called "Hormcresc" and directions for use were elaborated. One hundred frozen glands were processed and the "crude" hGH was purified by gel filtration on Sephadex G-100 and tested using double diffusion in agar gel, radioimmunoassay (RIA), rechromatography on Sephadex G-100 and disc PAGE. The experiments led to an extraction yield of 550 +/- 165 (means +/- SD) mg "clinical grade" hGH per 20 g of acetone powder. The elution pattern of Sephadex G-100 chromatography and of preparative PAGE as well as the pattern of disc PAGE showed that the "clinical grade" hGH is similar to the already known GH hormones: Raben Somatrotropin, Crescormon (Sweden) and hGH (FRG) but different from Sotropin-H (DDR). The "clinical grade" hGH in lyophilised form is similar to the GH preparations accepted by the European pharmacopoea; it is soluble in NaCl 0.15 M and painless on injection by comparison to hGH in powder form. A method was worked out for the extraction, isolation and purification of "highly pure" hGH using frozen pituitaries, which made it possible to isolate from the same batch of glands not only hGH but also luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin and thyroid stimulating hormone (TSH). During the purification of "crude" hGH on Sephadex G-100 a rather abundant fraction of MW of about 5000-15000 daltons was observed; this fraction, codified provisionally the "X" fraction does not contain hGH, as results from the RIA measurements. On disc electrophoresis, the purified hGH is not homogeneous: behind the main fast band three slower bands are observed. Studies concerning the comparison of our "highly pure" hGH with the hGH preparations recommended by WHO, are in progress in our laboratory.

Composition and microstructure of MTA and Aureoseal Plus: XRF, EDS, XRD and FESEM evaluation.

PubMed

Cianconi, L; Palopoli, P; Campanella, V; Mancini, M

2016-12-01

The aim of this study was to determine the chemical composition and the phases' microstructure of Aureoseal Plus (OGNA, Italy) and ProRoot MTA (Dentsply Tulsa Dental, USA) and to compare their characteristics. Study Design: Comparing Aureoseal Plus and ProRoot MTA microstructure by means of several analyses type. The chemical analysis of the two cements was assessed following the UNI EN ISO 196-2 norm. X-Ray fluorescence (XRF) was used to determine the element composition. The crystalline structure was analysed quantitatively using x-ray diffraction (XRD). Powders morphology was evaluated using a scanning electron microscope (SEM) with backscattering detectors, and a field emission scanning electron microscope (FESEM). Elemental analysis was performed by energy dispersive x-ray analysis (EDS). The semi-quantitative XRF analysis showed the presence of heavy metal oxides in both cements. The XRD spectra of the two cements reported the presence of dicalcium silicate, tricalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite, bismuth oxide and gypsum. SEM analysis showed that ProRoot MTA powder is less coarse and more homogeneous than Aureoseal. Both powders are formed by particles of different shapes: round, prismatic and oblong. The EDS analysis showed that some ProRoot MTA particles, differently from Aureoseal, contain Ca, Si, Al and Fe. Oblong particles in ProRoot and Aureoseal are rich of bismuth. The strong interest in developing new Portland cement-based endodontic sealers will create materials with increased handling characteristics and physicochemical properties. A thorough investigation on two cement powders was carried out by using XRF, XRD, SEM and EDS analysis. To date there was a lack of studies on Aureoseal Plus. This cement is similar in composition to ProRoot MTA. Despite that it has distinctive elements that could improve its characteristics, resulting in a good alternative to MTA.

Spectrochemical analysis of powdered biological samples using transversely excited atmospheric carbon dioxide laser plasma excitation

NASA Astrophysics Data System (ADS)

Zivkovic, Sanja; Momcilovic, Milos; Staicu, Angela; Mutic, Jelena; Trtica, Milan; Savovic, Jelena

2017-02-01

The aim of this study was to develop a simple laser induced breakdown spectroscopy (LIBS) method for quantitative elemental analysis of powdered biological materials based on laboratory prepared calibration samples. The analysis was done using ungated single pulse LIBS in ambient air at atmospheric pressure. Transversely-Excited Atmospheric pressure (TEA) CO2 laser was used as an energy source for plasma generation on samples. The material used for the analysis was a blue-green alga Spirulina, widely used in food and pharmaceutical industries and also in a few biotechnological applications. To demonstrate the analytical potential of this particular LIBS system the obtained spectra were compared to the spectra obtained using a commercial LIBS system based on pulsed Nd:YAG laser. A single sample of known concentration was used to estimate detection limits for Ba, Ca, Fe, Mg, Mn, Si and Sr and compare detection power of these two LIBS systems. TEA CO2 laser based LIBS was also applied for quantitative analysis of the elements in powder Spirulina samples. Analytical curves for Ba, Fe, Mg, Mn and Sr were constructed using laboratory produced matrix-matched calibration samples. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used as the reference technique for elemental quantification, and reasonably well agreement between ICP and LIBS data was obtained. Results confirm that, in respect to its sensitivity and precision, TEA CO2 laser based LIBS can be successfully applied for quantitative analysis of macro and micro-elements in algal samples. The fact that nearly all classes of materials can be prepared as powders implies that the proposed method could be easily extended to a quantitative analysis of different kinds of materials, organic, biological or inorganic.

Quantitative analysis of perfumes in talcum powder by using headspace sorptive extraction.

PubMed

Ng, Khim Hui; Heng, Audrey; Osborne, Murray

2012-03-01

Quantitative analysis of perfume dosage in talcum powder has been a challenge due to interference of the matrix and has so far not been widely reported. In this study, headspace sorptive extraction (HSSE) was validated as a solventless sample preparation method for the extraction and enrichment of perfume raw materials from talcum powder. Sample enrichment is performed on a thick film of poly(dimethylsiloxane) (PDMS) coated onto a magnetic stir bar incorporated in a glass jacket. Sampling is done by placing the PDMS stir bar in the headspace vial by using a holder. The stir bar is then thermally desorbed online with capillary gas chromatography-mass spectrometry. The HSSE method is based on the same principles as headspace solid-phase microextraction (HS-SPME). Nevertheless, a relatively larger amount of extracting phase is coated on the stir bar as compared to SPME. Sample amount and extraction time were optimized in this study. The method has shown good repeatability (with relative standard deviation no higher than 12.5%) and excellent linearity with correlation coefficients above 0.99 for all analytes. The method was also successfully applied in the quantitative analysis of talcum powder spiked with perfume at different dosages. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of Optimum Magnetic Behavior of NanoCrystalline CmFeAl Type Heusler Alloy Powders Using Response Surface Methodology

NASA Astrophysics Data System (ADS)

Srivastava, Y.; Srivastava, S.; Boriwal, L.

2016-09-01

Mechanical alloying is a novelistic solid state process that has received considerable attention due to many advantages over other conventional processes. In the present work, Co2FeAl healer alloy powder, prepared successfully from premix basic powders of Cobalt (Co), Iron (Fe) and Aluminum (Al) in stoichiometric of 60Co-26Fe-14Al (weight %) by novelistic mechano-chemical route. Magnetic properties of mechanically alloyed powders were characterized by vibrating sample magnetometer (VSM). 2 factor 5 level design matrix was applied to experiment process. Experimental results were used for response surface methodology. Interaction between the input process parameters and the response has been established with the help of regression analysis. Further analysis of variance technique was applied to check the adequacy of developed model and significance of process parameters. Test case study was performed with those parameters, which was not selected for main experimentation but range was same. Response surface methodology, the process parameters must be optimized to obtain improved magnetic properties. Further optimum process parameters were identified using numerical and graphical optimization techniques.

Biocompatible nanocrystalline natural bonelike carbonated hydroxyapatite synthesized by mechanical alloying in a record minimum time.

PubMed

Lala, S; Brahmachari, S; Das, P K; Das, D; Kar, T; Pradhan, S K

2014-09-01

Single phase nanocrystalline biocompatible A-type carbonated hydroxyapatite (A-cHAp) powder has been synthesized by mechanical alloying the stoichiometric mixture of CaCO3 and CaHPO4.2H2O powders in open air at room temperature within 2h of milling. The A-type carbonation in HAp is confirmed by FTIR analysis. Structural and microstructure parameters of as-milled powders are obtained from both Rietveld's powder structure refinement analysis and transmission electron microscopy. Size and lattice strain of nanocrystalline HAp particles are found to be anisotropic in nature. Mechanical alloying causes amorphization of a part of crystalline A-cHAp which is analogous to native bone mineral. Some primary bond lengths of as-milled samples are critically measured. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay test reveals high percentage of cell viability and hence confirms the biocompatibility of the sample. The overall results indicate that the processed A-cHAp has a chemical composition very close to that of biological apatite. Copyright © 2014 Elsevier B.V. All rights reserved.

Biofilm removal and antimicrobial activity of two different air-polishing powders: an in vitro study.

PubMed

Drago, Lorenzo; Del Fabbro, Massimo; Bortolin, Monica; Vassena, Christian; De Vecchi, Elena; Taschieri, Silvio

2014-11-01

Biofilm removal plays a central role in the prevention of periodontal and peri-implant diseases associated with microbial infections. Plaque debridement may be accomplished by air polishing using abrasive powders. In this study, a new formulation consisting of erythritol and chlorhexidine is compared with the standard glycine powder used in air-polishing devices. Their in vitro antimicrobial and antibiofilm effects on Staphylococcus aureus, Bacteroides fragilis, and Candida albicans are investigated. Biofilm was allowed to grow on sandblasted titanium disks and air polished with glycine or erythritol-chlorhexidine powders. A semiquantitative analysis of biofilm by spectrophotometric assay was performed. A qualitative analysis was also carried out by confocal laser scanning microscopy. Minimum inhibitory concentrations and minimum microbicidal concentrations were evaluated, together with the microbial recovery from the residual biofilm after air-polishing treatment. The combination of erythritol and chlorhexidine displayed stronger antimicrobial and antibiofilm activity than glycine against all microbial strains tested. Air polishing with erythritol-chlorhexidine seems to be a viable alternative to the traditional glycine treatment for biofilm removal.

Heat treatment's effects on hydroxyapatite powders in water vapor and air atmosphere

NASA Astrophysics Data System (ADS)

Karabulut, A.; Baştan, F. E.; Erdoǧan, G.; Üstel, F.

2015-03-01

Hydroxyapatite (HA; Ca10(PO4)6(OH)2) is the main chemical constituent of bone tissue (~70%) as well as HA which is a calcium phosphate based ceramic material forms inorganic tissue of bone and tooth as hard tissues is used in production of prosthesis for synthetic bone, fractured and broken bone restoration, coating of metallic biomaterials and dental applications because of its bio compatibility. It is known that Hydroxyapatite decomposes with high heat energy after heat treatment. Therefore hydroxyapatite powders that heated in water vapor will less decomposed phases and lower amorphous phase content than in air atmosphere. In this study high purity hydroxyapatite powders were heat treated with open atmosphere furnace and water vapor atmosphere with 900, 1000, 1200 °C. Morphology of same powder size used in this process by SEM analyzed. Chemical structures of synthesized coatings have been examined by XRD. The determination of particle size and morphological structure of has been characterized by Particle Sizer, and SEM analysis, respectively. Weight change of sample was recorded by thermogravimetric analysis (TGA) during heating and cooling.

Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): a potential NLO material.

PubMed

Dinakaran, Paul M; Kalainathan, S

2013-07-01

4-Chloro 4-nitrostilbene (CONS) a new organic nonlinear optical material has been synthesized. Employing slow evaporation method, good optical quality single crystals (dimensions up to 6×2×3 mm(3)) have been grown using ethyl methyl ketone (EMK) as a solvent. The grown crystals have been subjected to various characterizations such as single crystal X-ray diffraction, powder XRD, Fourier Transform Infrared spectroscopy (FTIR), proton NMR, solid UV absorption, SHG studies. Single crystal X-ray diffraction reveals that the crystal system belongs to monoclinic with noncentrosymmetric space group P21. The UV-Vis absorption spectrum has been recorded and found that the cut off wavelength is 380 nm. Functional groups and the structure of the title compound have been confirmed by FTIR and (1)H NMR spectroscopic analyses respectively. Molecular mass of the CONS confirmed by the high resolution mass spectral analysis .The thermal behavior of the grown crystal has been studied by TG/DTA analysis and it shows the melting point is at 188.66 °C. Dislocations and growth pattern present in the grown crystal revealed by the etching study. The mechanical strength of the CONS crystal has been studied by Vicker's hardness measurement. The SHG efficiency of the grown crystal has been determined by Kurtz and Perry powder test which revealed that the CONS crystal (327 mV) has 15 times greater efficiency than that of KDP (21.7 mV). Copyright © 2013 Elsevier B.V. All rights reserved.

Investigation of nanocrystalline zinc chromite obtained by two soft chemical routes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gingasu, Dana; Mindru, Ioana, E-mail: imandru@yahoo.com; Culita, Daniela C.

2014-01-01

Graphical abstract: - Highlights: • Two soft chemical routes to synthesize zinc chromites are described. • Glycine is used as chelating agent (precursor method) and fuel (solution combustion method). • The synthesized chromites have crystallite size in the range of 18–27 nm. • An antiferromagnetic (AFM) transition is observed at about T{sub N} ∼ 18 K. - Abstract: Zinc chromite (ZnCr{sub 2}O{sub 4}) nanocrystalline powders were obtained by two different chemical routes: the precursor method and the solution combustion method involving glycine-nitrates. The complex compound precursors, [ZnCr{sub 2}(NH{sub 2}CH{sub 2}COO){sub 8}]·9H{sub 2}O and [ZnCr{sub 2}(NH{sub 2}CH{sub 2}COOH){sub 4.5}]·(NO{sub 3}){sub 8}·6H{submore » 2}O, were characterized by chemical analysis, infrared spectroscopy (IR), ultraviolet–visible spectroscopy (UV–vis) and thermal analysis. The structure, morphology, surface chemistry and magnetic properties of ZnCr{sub 2}O{sub 4} powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), infrared and Raman spectroscopy (RS), ultraviolet–visible spectroscopy (UV–vis) and magnetic measurements. X-ray diffraction patterns indicated the chromite spinel phase with good crystallinity and an average crystallite size of approximately 18–27 nm. The band gap values ranged between 3.31 and 3.33 eV. The magnetic measurements indicated an antiferromagnetic transition at T{sub N} ∼ 17.5/18 K.« less

Latex-induced occupational asthma: time trend in incidence and relationship with hospital glove policies.

PubMed

Vandenplas, O; Larbanois, A; Vanassche, F; François, S; Jamart, J; Vandeweerdt, M; Thimpont, J

2009-03-01

Natural rubber latex (NRL) has become as a major cause of occupational asthma (OA) in workers using NRL gloves. Few population-based studies have assessed the impact of changes in the patterns of glove usage on the incidence of NRL-induced OA. To characterize the time trends in incident cases of NRL-induced OA in Belgium and examine whether incidence rates were related to the types of gloves used in hospitals. Incident cases of NRL-induced OA were identified through a retrospective review of all claims submitted to the Workers' Compensation Board up to December 2004. Based on the results of diagnostic procedures, the diagnosis of NRL-induced OA was categorized as definite, probable, unlikely, or indeterminate. The patterns of glove usage were characterized through a questionnaire survey of Belgian hospitals. A total of 298 claims for NRL-induced OA were identified, including 127 subjects with definite OA and 68 with probable OA. Categorized by the year of asthma onset, the incident cases of definite and probable NRL-induced OA markedly decreased from 1999 onwards. The use of powdered NRL gloves fell from 80.9% in 1989 to 17.9% in 2004. Powdered NRL gloves were predominantly substituted with NRL-free gloves, especially in the case of non-sterile procedures. These national compensation-based data confirm that a persistent decline in the incidence of NRL-induced OA has occurred since late 1990s. This downward trend has temporally been associated with a decreasing usage of powdered NRL, further supporting a beneficial role of changes in glove policies.

Rietveld analysis of the cubic crystal structure of Na-stabilized zirconia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fagherazzi, G.; Canton, P.; Benedetti, A.

Using x-ray Rietveld analysis the fcc (fluorite-type) structure of a Na-containing nanocrystalline zirconia powder (9.5 nm estimated of crystallite size) obtained by precipitation and subsequent calcination has been confirmed. The result shows that using conventional x-ray diffraction techniques the cubic crystallographic form of ZrO{sub 2} from the tetragonal one in nanosized powders. These conclusions are supported by the findings of independent Raman scattering experiments. {copyright} {ital 1997 Materials Research Society.}

A novel approach to determine the thermal transition of gum powder/hydro-gels using dynamic mechanical analysis

NASA Astrophysics Data System (ADS)

Nagamadhu, M.; Jeyaraj, P.; Kumar, G. C. Mohan

2018-04-01

The dynamic characterization of materials plays a major role in the present area. The many researchers are worked on solid materials and its characterization, it can be tested using dynamic mechanical analyzer (DMA), however, no such work on powder a semiliquid samples. The powder and liquid samples can also easily characterization as like solid samples using DMA. These powder samples are analyzed with a material pocket method which can be used to accurately determine very low levels of variation in powder properties, due to the high sensitivity of DMA to glass transitions. No such DMA studies on hydrogel and Gum powders. The gum powders are used in various applications start from food industries, pharmacy, natural gums paste, biomedical applications etc. among all this applications gum Ghatti is one of the powders using for varies applications. Around 50 milligrams of Ghatti powders are placed inside material pocket and analyzed storage modulus (G'), loss modulus (G″) and tan delta (δ). Also, understand the curing and glass transition effect using water, glycerin and superplastic from room temperature to 200°C. The result shows that storage modulus decreases with increase in temperature in pure Ghatti powder. The surprising improvement in storage modulus was found with an increase in temperature with addition of water, glycerin, and superplastic. However, loss modulus and tan delta are also having very significant influence and also shows a clear peak of the tan delta. The loss modulus results were found to be improved by adding solidifying agents, along with this water and superplastic better influence. But glycerine found to be hydrogel in nature and thermodynamic properties are much influenced by frequency.

Effect of Annealing Temperature on Bi3.25La0.75Ti3O12 Powders for Humidity Sensing Properties

NASA Astrophysics Data System (ADS)

Zhang, Yong; He, Jinping; Yuan, Mengjiao; Jiang, Bin; Li, Peiwen; Tong, Yexing; Zheng, Xuejun

2017-01-01

Bi3.25La0.75Ti3O12 (BLT) powders have been synthesized via the metal-organic decomposition method with annealing of the BLT precursor solution at 350°C, 450°C, 550°C, 650°C or 750°C. The crystalline structure and morphology of the BLT powders were characterized by x-ray diffraction analysis, field-emission scanning electron microscopy, energy-dispersive x-ray spectroscopy, and specific surface and pore size analyses. The humidity sensing properties of the BLT powders annealed at the five temperatures were investigated to determine the effect of annealing temperature. The annealing temperature strongly influenced the grain size, pore size distribution, and specific surface area of the BLT powders, being largely correlated to their humidity sensing properties. The specific surface area of the BLT powder annealed at 550°C was 68.2 m2/g, much larger than for the other annealing temperatures, and the majority of the pores in the BLT powder annealed at 550°C were mesoporous, significantly increasing the adsorption efficiency of water vapor onto the surface of the material. The impedance of the BLT powder annealed at 550°C varied by more than five orders of magnitude over the whole humidity range at working frequency of 100 Hz, being approximately five times greater than for BLT powders annealed at other temperatures. The response time was about 8 s, with maximum hysteresis of around 3% relative humidity. The BLT powder annealed at 550°C exhibited the best humidity sensing properties compared with the other annealing temperatures. We expect that these results will offer useful guidelines for preparation of humidity sensing materials.

Morphological, chemical and structural characterisation of deciduous enamel: SEM, EDS, XRD, FTIR and XPS analysis.

PubMed

Zamudio-Ortega, C M; Contreras-Bulnes, R; Scougall-Vilchis, R J; Morales-Luckie, R A; Olea-Mejía, O F; Rodríguez-Vilchis, L E

2014-09-01

The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.

Analysis of Thermo-Diffusive Cellular Instabilities in Continuum Combustion Fronts

NASA Astrophysics Data System (ADS)

Azizi, Hossein; Gurevich, Sebastian; Provatas, Nikolas; Department of Physics, Centre Physics of Materials Team

We explore numerically the morphological patterns of thermo-diffusive instabilities in combustion fronts with a continuum solid fuel source, within a range of Lewis numbers, focusing on the cellular regime. Cellular and dendritic instabilities are found at low Lewis numbers. These are studied using a dynamic adaptive mesh refinement technique that allows very large computational domains, thus allowing us to reduce finite size effects that can affect or even preclude the emergence of these patterns. The distinct types of dynamics found in the vicinity of the critical Lewis number. These types of dynamics are classified as ``quasi-linear'' and characterized by low amplitude cells that may be strongly affected by the mode selection mechanism and growth prescribed by the linear theory. Below this range of Lewis number, highly non-linear effects become prominent and large amplitude, complex cellular and seaweed dendritic morphologies emerge. The cellular patterns simulated in this work are similar to those observed in experiments of flame propagation over a bed of nano-aluminum powder burning with a counter-flowing oxidizer conducted by Malchi et al. It is noteworthy that the physical dimension of our computational domain is roughly close to their experimental setup. This work was supported by a Canadian Space Agency Class Grant ''Percolating Reactive Waves in Particulate Suspensions''. We thank Compute Canada for computing resources.

Illicit Drug Use in a Community-Based Sample of Heterosexually Identified Emerging Adults

ERIC Educational Resources Information Center

Halkitis, Perry N.; Manasse, Ashley N.; McCready, Karen C.

2010-01-01

In this study we assess lifetime and recent drug use patterns among 261 heterosexually identified 18- to 25-year-olds through brief street intercept surveys conducted in New York City. Marijuana, hallucinogens, powder cocaine, and ecstasy were the most frequently reported drugs for both lifetime and recent use. Findings further suggest significant…

Frequency analysis for modulation-enhanced powder diffraction.

PubMed

Chernyshov, Dmitry; Dyadkin, Vadim; van Beek, Wouter; Urakawa, Atsushi

2016-07-01

Periodic modulation of external conditions on a crystalline sample with a consequent analysis of periodic diffraction response has been recently proposed as a tool to enhance experimental sensitivity for minor structural changes. Here the intensity distributions for both a linear and nonlinear structural response induced by a symmetric and periodic stimulus are analysed. The analysis is further extended for powder diffraction when an external perturbation changes not only the intensity of Bragg lines but also their positions. The derived results should serve as a basis for a quantitative modelling of modulation-enhanced diffraction data measured in real conditions.

X-ray diffraction, spectroscopic and mechanical studies on potential organic NLO materials of metaNitroaniline and N-3-Nitrophenyl Acetamide single crystals

NASA Astrophysics Data System (ADS)

Senthil, S.; Madhavan, J.

2015-02-01

In the present paper, attempts were made to grow good quality metaNitroaniline (mNA) and N-3-Nitrophenyl (3-NAA) single crystals. The lattice parameter values from the Powder X-ray diffraction pattern confirms that mNA belongs to orthorhombic crystal system with the unit cell parameter values of a = 6.501 Å, b = 19.330 Å and c = 5.082 Å with space group Pbc21. Similarly the powder XRD data indicates that 3-NAA crystal retained its monoclinic structure with lattice parameter values a = 9.762 Å, b =13.287 Å, c =13.226 Å, and β = 102.99°. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by Fourier Transform infrared spectroscopy technique. The SHG efficiency of mNA and 3NAA was determined by Kurtz and Perry powder technique. The Optical absorption study confirms the suitability of the crystals for device applications. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester.

Synthesis and characterization of graphene oxide using modified Hummer's method

NASA Astrophysics Data System (ADS)

Kaur, Manpreet; Kaur, Harsimran; Kukkar, Deepak

2018-05-01

In the present study, a simple approach has been followed for the synthesis of graphene oxide (GO) using modified Hummers method in which graphite powder was oxidized in the presence of concentrated H2SO4 and KMnO4. The amount of NaNO3 and KMnO4 was varied to produce sheet like structure. The varied concentrations of NaNO3 and KMnO4 resulted in yielding large amount of the product. Structural, morphological and physicochemical features of the product were studied using UV-Visible spectrophotometer, Fourier Transform infrared spectroscopy (FTIR), and crystal structure was determined using X-ray powder diffraction (XRD). UV-Vis spectra of GO was observed at a maximum absorption of 230 nm due to (π-π*) transition of atomic carbon-carbon bonds. FTIR spectra revealed the presence of oxygen containing functional groups which ensures the complete exfoliation of graphite into graphene oxide X-ray powder diffraction pattern of the product showed the diffraction peak at (2θ = 26.7°) with an interlayer spacing of 0.334 nm. All the above characterizations successfully confirmed the formation of GO.

Powder Metallurgy Processing of a WxTaTiVCr High-Entropy Alloy and Its Derivative Alloys for Fusion Material Applications.

PubMed

Waseem, Owais Ahmed; Ryu, Ho Jin

2017-05-16

The W x TaTiVCr high-entropy alloy with 32at.% of tungsten (W) and its derivative alloys with 42 to 90at.% of W with in-situ TiC were prepared via the mixing of elemental W, Ta, Ti, V and Cr powders followed by spark plasma sintering for the development of reduced-activation alloys for fusion plasma-facing materials. Characterization of the sintered samples revealed a BCC lattice and a multi-phase structure. The selected-area diffraction patterns confirmed the formation of TiC in the high-entropy alloy and its derivative alloys. It revealed the development of C15 (cubic) Laves phases as well in alloys with 71 to 90at.% W. A mechanical examination of the samples revealed a more than twofold improvement in the hardness and strength due to solid-solution strengthening and dispersion strengthening. This study explored the potential of powder metallurgy processing for the fabrication of a high-entropy alloy and other derived compositions with enhanced hardness and strength.

Permeability model of sintered porous media: analysis and experiments

NASA Astrophysics Data System (ADS)

Flórez Mera, Juan Pablo; Chiamulera, Maria E.; Mantelli, Marcia B. H.

2017-11-01

In this paper, the permeability of porous media fabricated from copper powder sintering process was modeled and measured, aiming the use of the porosity as input parameter for the prediction of the permeability of sintering porous media. An expression relating the powder particle mean diameter with the permeability was obtained, based on an elementary porous media cell, which is physically represented by a duct formed by the arrangement of spherical particles forming a simple or orthorhombic packing. A circular duct with variable section was used to model the fluid flow within the porous media, where the concept of the hydraulic diameter was applied. Thus, the porous is modeled as a converging-diverging duct. The electrical circuit analogy was employed to determine two hydraulic resistances of the cell: based on the Navier-Stokes equation and on the Darcýs law. The hydraulic resistances are compared between themselves and an expression to determine the permeability as function of average particle diameter is obtained. The atomized copper powder was sifted to reduce the size dispersion of the particles. The porosities and permeabilities of sintered media fabricated from powders with particle mean diameters ranging from 20 to 200 microns were measured, by means of the image analysis method and using an experimental apparatus. The permeability data of a porous media, made of copper powder and saturated with distilled water, was used to compare with the permeability model. Permeability literature models, which considers that powder particles have the same diameter and include porosity data as input parameter, were compared with the present model and experimental data. This comparison showed to be quite good.

Self-organizing map analysis using multivariate data from theophylline powders predicted by a thin-plate spline interpolation.

PubMed

Yasuda, Akihito; Onuki, Yoshinori; Kikuchi, Shingo; Takayama, Kozo

2010-11-01

The quality by design concept in pharmaceutical formulation development requires establishment of a science-based rationale and a design space. We integrated thin-plate spline (TPS) interpolation and Kohonen's self-organizing map (SOM) to visualize the latent structure underlying causal factors and pharmaceutical responses. As a model pharmaceutical product, theophylline powders were prepared based on the standard formulation. The angle of repose, compressibility, cohesion, and dispersibility were measured as the response variables. These responses were predicted quantitatively on the basis of a nonlinear TPS. A large amount of data on these powders was generated and classified into several clusters using an SOM. The experimental values of the responses were predicted with high accuracy, and the data generated for the powders could be classified into several distinctive clusters. The SOM feature map allowed us to analyze the global and local correlations between causal factors and powder characteristics. For instance, the quantities of microcrystalline cellulose (MCC) and magnesium stearate (Mg-St) were classified distinctly into each cluster, indicating that the quantities of MCC and Mg-St were crucial for determining the powder characteristics. This technique provides a better understanding of the relationships between causal factors and pharmaceutical responses in theophylline powder formulations. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association

The adhesive strength and initial viscosity of denture adhesives.

PubMed

Han, Jian-Min; Hong, Guang; Dilinuer, Maimaitishawuti; Lin, Hong; Zheng, Gang; Wang, Xin-Zhi; Sasaki, Keiichi

2014-11-01

To examine the initial viscosity and adhesive strength of modern denture adhesives in vitro. Three cream-type denture adhesives (Poligrip S, Corect Cream, Liodent Cream; PGS, CRC, LDC) and three powder-type denture adhesives (Poligrip Powder, New Faston, Zanfton; PGP, FSN, ZFN) were used in this study. The initial viscosity was measured using a controlled-stress rheometer. The adhesive strength was measured according to ISO-10873 recommended procedures. All data were analyzed independently by one-way analysis of variance combined with a Student-Newman-Keuls multiple comparison test at a 5% level of significance. The initial viscosity of all the cream-type denture adhesives was lower than the powder-type adhesives. Before immersion in water, all the powder-type adhesives exhibited higher adhesive strength than the cream-type adhesives. However, the adhesive strength of cream-type denture adhesives increased significantly and exceeded the powder-type denture adhesives after immersion in water. For powder-type adhesives, the adhesive strength significantly decreased after immersion in water for 60 min, while the adhesive strength of the cream-type adhesives significantly decreased after immersion in water for 180 min. Cream-type denture adhesives have lower initial viscosity and higher adhesive strength than powder type adhesives, which may offer better manipulation properties and greater efficacy during application.

Temozolomide-based dry powder formulations for lung tumor-related inhalation treatment.

PubMed

Wauthoz, Nathalie; Deleuze, Philippe; Saumet, Amandine; Duret, Christophe; Kiss, Robert; Amighi, Karim

2011-04-01

Temozolomide dry powder formulations for inhalation, performed with no excipient or with a lipid or lactose coating, have been evaluated. The particle size of raw temozolomide in suspension was reduced by a high-pressure homogenizing technique, and the solvent was evaporated by spray-drying to obtain a dry powder. The physicochemical properties of this powder were evaluated and included its crystalline state, thermal properties, morphology, particle size and moisture and drug content, and these properties were determined by X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, laser light scattering, thermogravimetric analysis and high-performance liquid chromatography, respectively. The aerodynamic properties and release profiles were also evaluated using a multistage liquid impinger and a modified USP type 2 dissolution apparatus adapted for inhaler products, respectively. The dry powder inhalation formulations had a high temozolomide content that ranged from 70% to 100% in the crystalline state and low moisture content. Aerodynamic evaluations showed high fine-particle fractions of up to 51% related to the metered dose. The dissolution profile revealed a similarly fast temozolomide release from the formulations. Dry temozolomide powder formulations, based on the use of acceptable excipients for inhalation and showing good dispersion properties, represent an attractive alternative for use in local lung cancer therapy.

Evaluation of Turmeric Powder Adulterated with Metanil Yellow Using FT-Raman and FT-IR Spectroscopy

PubMed Central

Dhakal, Sagar; Chao, Kuanglin; Schmidt, Walter; Qin, Jianwei; Kim, Moon; Chan, Diane

2016-01-01

Turmeric powder (Curcuma longa L.) is valued both for its medicinal properties and for its popular culinary use, such as being a component in curry powder. Due to its high demand in international trade, turmeric powder has been subject to economically driven, hazardous chemical adulteration. This study utilized Fourier Transform-Raman (FT-Raman) and Fourier Transform-Infra Red (FT-IR) spectroscopy as separate but complementary methods for detecting metanil yellow adulteration of turmeric powder. Sample mixtures of turmeric powder and metanil yellow were prepared at concentrations of 30%, 25%, 20%, 15%, 10%, 5%, 1%, and 0.01% (w/w). FT-Raman and FT-IR spectra were acquired for these mixture samples as well as for pure samples of turmeric powder and metanil yellow. Spectral analysis showed that the FT-IR method in this study could detect the metanil yellow at the 5% concentration, while the FT-Raman method appeared to be more sensitive and could detect the metanil yellow at the 1% concentration. Relationships between metanil yellow spectral peak intensities and metanil yellow concentration were established using representative peaks at FT-Raman 1406 cm−1 and FT-IR 1140 cm−1 with correlation coefficients of 0.93 and 0.95, respectively. PMID:28231130

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thimmaiah, Srinivasa; Tener, Zachary; Lamichhane, Tej N.

Here, the γ-region of the Mn–Al phase diagram between 45 and 70 at.% Al was re-investigated by a combination of powder and single crystal X-ray diffraction as well as EDS analysis to establish the distribution of Mn and Al atoms. Single crystals of γ-Mn 5–x Al 8+x were grown using Sn-flux at 650 °C. The crystal structure, atomic coordinates and site occupancy parameters of γ-Mn 5–x Al 8+x phases were refined from single crystal X-ray data. The γ-Mn 5-x Al 8+x phase adopts the rhombohedral Cr 5Al 8-type structure rather than a cubic γ-brass structure. The refined compositions from twomore » crystals extracted from the Al-rich and Mn-rich sides are, respectively, Mn 4.76Al 8.24(2) (I) and Mn 6.32Al 6.68(2) (II). The structure was refined in the acentric R3m space group (No.160, Z=6), in order to compare with other reported rhombohedral γ-brasses. In addition, according to X-ray powder diffraction analysis, at the Al-rich side the γ-phase coexists with LT–Mn 4Al 11 and, at the Mn-rich side, with a hitherto unknown phase. The refined lattice parameters from powder patterns fall in the range a=12.6814(7)–12.6012(5) Å and c=7.9444(2)–7.9311(2) Å from Al-rich to Mn-rich loadings, and the corresponding rhombohedral angles distorted from a pseudo-cubic cell were found to be 89.1(1)°–88.9(1)°. Magnetic susceptibility and magnetization studies of Mn 4.92Al 8.08(2) are consistent with moment bearing Mn and suggest a spin glass state below 27 K. Tight-binding electronic structure calculations (LMTO-ASA with LSDA) showed that the calculated Fermi level for γ-“Mn 5Al 8” falls within a pseudogap of the density of states, a result which is in accordance with a Hume-Rothery stabilization mechanism γ-brass type phases.« less

Entrainment of lactose inhalation powders: a study using laser diffraction.

PubMed

Watling, C P; Elliott, J A; Cameron, R E

2010-07-11

We have investigated the mechanism of entrainment of lactose inhalation blends released from a dry powder inhaler using a diffraction particle size analyser (Malvern Spraytec). Whether a powder blend entrains as a constant stream of powder (the "erosion" mechanism) or as a few coarse plugs (the "fracture" mechanism) was found by comparing transmission data with particle size information. This technique was then applied to a lactose grade with 0, 5 and 10wt% added fine particles. As the wt% fines increased, the entrainment mechanism was found to change from a mild fracture, consisting of multiple small plugs, to more severe fracture with fewer plugs. The most severe fracture mechanism consisted of either the powder reservoir emptying as a single plug, or of the reservoir emptying after a delay of the order of 0.1s due to the powder sticking to its surroundings. Further to this, three different inhalation grades were compared, and the severity of the fracture was found to be inversely proportional to the flowability of the powder (measured using an annular ring shear tester). By considering the volume of aerosolised fine particles in different blends it was determined that the greater the volume of fines added to a powder, the smaller the fraction of fines that were aerosolised. This was attributed to different behaviour when fines disperse from carrier particles compared with when they disperse from agglomerates of fines. In summary, this paper demonstrates how laser diffraction can provide a more detailed analysis of an inhalation powder than just its size distribution. 2010. Published by Elsevier B.V. All rights reserved.

Laser-induced breakdown spectroscopy for quantitative spectrochemical analysis of geological materials: effects of the matrix and simultaneous determination.

PubMed

Anzano, Jesús M; Villoria, Mark A; Ruíz-Medina, Antonio; Lasheras, Roberto J

2006-08-11

A microscopic laser-induced breakdown spectrometer was used to evaluate the analytical matrix effect commonly observed in the analysis of geological materials. Samples were analyzed in either the powder or pressed pellet forms. Calibration curves of a number of iron and aluminum compounds showed a linear relationship between the elemental concentration and peak intensity. A direct determination of elemental content can thus be made from extrapolation on these calibration curves. To investigate matrix effects, synthetic model samples were prepared from various iron and aluminum compounds spiked with SiO2 and CaCO3. The addition of these matrices had a pronounced analytical effect on those compounds prepared as pressed pellets. However, results indicated the absence of matrix effects when the samples were presented to the laser as loose powders on tape and results were compared to certified values, indicating the reliability of this approach for accurate analysis, provided the sample particle diameters are greater than approximately 100 microm. Finally, the simultaneous analysis of two different elements was demonstrated using powders on tape.

Microstructural Examination of Oxidized Fe_(14-x) Nb5_x Alloy Produced from Powders Prepared by Mechanical Alloying

NASA Astrophysics Data System (ADS)

Demirkıran, A. Şükran; Sen, Saduman; Ozdemir, Ozkan; Sen, Ugur

In the present study, ferrous niobium, ferrous boron and iron were used as starting powders. The mixture of the powders which were calculated to give the designed compositions was prepared by using planetary high energy ball mill. Mechanically alloyed powders were pressed and sintered at 1350°C for 120 min in Ar atmosphere. The cyclic oxidation experiments were carried out in an electrical furnace at 650, 750 and 850 °C in open atmosphere for 96 h. The specimens were periodically weighed for the determination of weight change. Before and after oxidation, the present phases of the samples were determined by X-ray diffraction analysis (XRD). The microstructural characterizations were realized using scanning electron microscopy (SEM) with EDS attachment.

Numerical and Experimental Study of Ti6Al4V Components Manufactured Using Powder Bed Fusion Additive Manufacturing

NASA Astrophysics Data System (ADS)

Zielinski, Jonas; Mindt, Hans-Wilfried; Düchting, Jan; Schleifenbaum, Johannes Henrich; Megahed, Mustafa

2017-12-01

Powder bed fusion additive manufacturing of titanium alloys is an interesting manufacturing route for many applications requiring high material strength combined with geometric complexity. Managing powder bed fusion challenges, including porosity, surface finish, distortions and residual stresses of as-built material, is the key to bringing the advantages of this process to production main stream. This paper discusses the application of experimental and numerical analysis towards optimizing the manufacturing process of a demonstration component. Powder characterization including assessment of the reusability, assessment of material consolidation and process window optimization is pursued prior to applying the identified optima to study the distortion and residual stresses of the demonstrator. Comparisons of numerical predictions with measurements show good correlations along the complete numerical chain.

The Influence of Duration of Mechanical Activation of Titanium Powder on its Morphology, Microstructure, and Microhardness

NASA Astrophysics Data System (ADS)

Ditenberg, I. A.; Korchagin, M. A.; Pinzhin, Yu. P.; Melnikov, V. V.; Tyumentsev, A. N.; Grinyaev, K. V.; Smirnov, I. V.; Radishevskii, V. L.; Tsverova, A. S.; Sukhanov, I. I.

2017-10-01

Using the methods of X-ray diffraction analysis and scanning and transmission electron microscopy, an investigation of the influence of duration of mechanical activation on morphology and structure of titanium powder is performed. In the course of processing the following stages of material transformation are revealed: fragmentation of the initial powder, conglomeration, and ovalization of the conglomerates. It is found that when the duration of mechanical activation increases, the characteristic size of coherent scattering regions is significantly decreased, which is accompanied by an increase in the value of microdistortions and intensive fragmentation of the crystal lattice inside powder particles followed by the formation of highly defective nanostructured states. The transformation of microstructure is accompanied by a considerable increase in microhardness.

Optimal methodologies for terahertz time-domain spectroscopic analysis of traditional pigments in powder form

NASA Astrophysics Data System (ADS)

Ha, Taewoo; Lee, Howon; Sim, Kyung Ik; Kim, Jonghyeon; Jo, Young Chan; Kim, Jae Hoon; Baek, Na Yeon; Kang, Dai-ill; Lee, Han Hyoung

2017-05-01

We have established optimal methods for terahertz time-domain spectroscopic analysis of highly absorbing pigments in powder form based on our investigation of representative traditional Chinese pigments, such as azurite [blue-based color pigment], Chinese vermilion [red-based color pigment], and arsenic yellow [yellow-based color pigment]. To accurately extract the optical constants in the terahertz region of 0.1 - 3 THz, we carried out transmission measurements in such a way that intense absorption peaks did not completely suppress the transmission level. This required preparation of pellet samples with optimized thicknesses and material densities. In some cases, mixing the pigments with polyethylene powder was required to minimize absorption due to certain peak features. The resulting distortion-free terahertz spectra of the investigated set of pigment species exhibited well-defined unique spectral fingerprints. Our study will be useful to future efforts to establish non-destructive analysis methods of traditional pigments, to construct their spectral databases, and to apply these tools to restoration of cultural heritage materials.

Synthesis and characterization of CdO nano particles by the sol-gel method

NASA Astrophysics Data System (ADS)

Vadgama, V. S.; Vyas, R. P.; Jogiya, B. V.; Joshi, M. J.

2017-05-01

Cadmium Oxide (CdO) is an inorganic compound and one of the main precursors to other cadmium compounds. It finds applications in cadmium plating, storage batteries, in transparent conducting film, etc. Here, an attempt is made to synthesize CdO nano particles by sol-gel technique. The gel was prepared using cadmium nitrate tetra hydrate (Cd(NO3)2.4H2O) and aqueous ammonium hydroxide (NH4OH) as a precursor. The synthesized powder is further characterized by techniques like Powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Thermal gravimetric analysis (TGA). Powder XRD analysis suggested the nano-crystalline nature of the sample with the cubic crystal system. Nano scaled particles of spherical morphology with the size ranging from 50-100 nm are observed from TEM images. While, FT-IR study is used to confirm the presence of different functional groups. Thermo-gravimetric analysis suggests the highly thermally stable nature of the samples. The results are discussed.

Identification of low amount of irradiated spices (red pepper, garlic, ginger powder) with luminescence analysis

NASA Astrophysics Data System (ADS)

Kim, Byeong-Keun; Akram, Kashif; Kim, Cheong-Tae; Kang, Na-Roo; Lee, Jin-Won; Ryang, Jun-Hwan; Kwon, Joong-Ho

2012-08-01

For the identification of irradiated food, current analysis methods have limitations regarding presence and stability of radiation-induced markers. In this study, different spice blends with small quantity of different irradiated (0, 1 and 10 kGy) spice powders, such as red pepper, garlic or ginger, were investigated using PSL and TL techniques. In PSL-based screening analysis, the spice blends containing 10% of irradiated materials (1 or 10 kGy) were determined as intermediate or positive. In TL results, the blends containing 1% of 1 or 10 kGy-irradiated spices showed the typical TL glow curves that could be interpreted as positive. The blends with irradiated garlic powder provided more good results where identification was possible at 0.5% mixing of irradiated sample. However, the TL ratios of all spice blends were <0.1 and only TL glow curve shape and intensity may be used to discriminate the samples having irradiated component.

Effect of organic fuels on surface area and photocatalytic activity of scheelite CaWO4 nanoparticles

NASA Astrophysics Data System (ADS)

Manjunath, Kusuma; Gujjarahalli Thimmanna, Chandrappa

2018-03-01

Discrete nanoscale calcium tungstate (CaWO4) nanoparticles with exquisite photocatalytic activities were synthesized through ultra-rapid solution combustion route. Here, we aim to study the effect of different fuels on the synthesis of CaWO4 nanoparticles which lead to improve the characteristic properties and morphological evolution of the powders. From BET surface area measurement, it is observed that CaWO4 nanoparticles synthesized by using citric acid as fuel exhibits relatively large surface area (31.78 m2 g‑1) as compared to other fuels. The powder x-ray diffraction (PXRD) studies reveal that CaWO4 nanoparticles belong to scheelite type tetragonal system. The morphology of CaWO4 nanoparticles investigated using scanning electron microscopy (SEM) reveals that the powders are highly porous and agglomerated. Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) images of the CaWO4 nanoparticles show that a well-dispersed nearly oval-shaped nanoparticles with variable dimensions and lattice spacing that depends on the type of fuels used in the synthesis. The selected area electron diffraction (SAED) patterns of CaWO4 nanoparticles exhibit several concentric rings with bright spots indicating the polycrystalline nature of the powders. Investigation on photocatalytic activity of CaWO4 nanoparticles synthesized using citric acid shows highest (∼93%) degradation of methylene blue (MB).

Detection and identification of immobilized low-volatility organophosphates by desorption ionization mass spectrometry

NASA Astrophysics Data System (ADS)

Hagan, Nathan A.; Cornish, Timothy J.; Pilato, Robert S.; van Houten, Kelly A.; Antoine, Miquel D.; Lippa, Timothy P.; Becknell, Alan F.; Demirev, Plamen A.

2008-12-01

Two desorption ionization mass spectrometry (MS) techniques - ultraviolet laser desorption/ionization (LDI) and desorption electrospray ionization (DESI) - have been used to detect and identify low-volatility organophosphates when deposited on surfaces or loaded into the pore volume of porous inorganic or polymeric organic powders. The insecticides malathion and dicrotophos were chosen for this study as simulants of low vapor pressure chemical warfare agents which are inherently difficult to detect directly by traditional methods. Both liquid and powdered forms of either insecticide were readily detected by LDI or DESI MS. LDI MS was performed on a miniaturized home-built time-of-flight (TOF) mass spectrometer and a commercial TOF/TOF instrument. For DESI MS, a home-built ion source was interfaced to a commercial quadrupole ion trap. In LDI, intact molecular ion signatures could be acquired by using an appropriate cationizing agent and powder additive in positive ion mode. Tandem MS was used to confirm the identity of each analyte based on the observed characteristic fragmentation pattern. In DESI, less than 100 pg of the liquid insecticides spotted on clean surfaces were detected, while detection limits for the powder-loaded preparations were lower than 1 [mu]g. The effects of sample surface, salt additives, nanoparticle admixtures, and analyte solubility on the LDI and DESI MS sensitivity have been investigated as well.

The use of nano-sized eggshell powder for calcium fortification of cow?s and buffalo?s milk yogurts.

PubMed

El-Shibiny, Safinaze; El-Gawad, Mona Abd El-Kader Mohamed Abd; Assem, Fayza Mohamed; El-Sayed, Samah Mosbah

2018-01-01

Calcium is an essential element for the growth, activity, and maintenance of the human body. Eggshells are a waste product which has received growing interest as a cheap and effective source of dietary calcium. Yogurt is a food which can be fortified with functional additives, including calcium. The aim of this study was to produce yogurt with a high calcium content by fortification with nano-sized eggshell powder (nano-ESP). Nano-sized ESP was prepared from pre-boiled and dried eggshell, using a ball mill. Yogurt was prepared from cow’s milk supplemented with 3% skimmed milk powder, and from buffalo’s milk fortified with 0.1, 0.2 and 0.3% and 0.1, 0.3 and 0.5% nano-ESP respectively. Electron microscopic transmission showed that the powder consisted of nano-sized crystalline struc- tures (~10 nm). Laser scattering showed that particles followed a normal distribution pattern with z-average of 590.5 nm, and had negative zeta-potential of –9.33 ±4.2 mV. Results regarding changes in yogurt composi- tion, acid development, calcium distribution, biochemical changes, textural parameters and sensory attributes have been presented and discussed. The addition of up to 0.3% nano-ESP made cow and buffalo high-calcium yogurts with an acceptable composition and quality. High-calcium yogurt may offer better health benefits, such as combating osteoporosis.

Deposition of conductive TiN shells on SiO2 nanoparticles with a fluidized bed ALD reactor

NASA Astrophysics Data System (ADS)

Didden, Arjen; Hillebrand, Philipp; Wollgarten, Markus; Dam, Bernard; van de Krol, Roel

2016-02-01

Conductive TiN shells have been deposited on SiO2 nanoparticles (10-20 nm primary particle size) with fluidized bed atomic layer deposition using TDMAT and NH3 as precursors. Analysis of the powders confirms that shell growth saturates at approximately 0.4 nm/cycle at TDMAT doses of >1.2 mmol/g of powder. TEM and XPS analysis showed that all particles were coated with homogeneous shells containing titanium. Due to the large specific surface area of the nanoparticles, the TiN shells rapidly oxidize upon exposure to air. Electrical measurements show that the partially oxidized shells are conducting, with apparent resistivity of approximately 11 kΩ cm. The resistivity of the powders is strongly influenced by the NH3 dose, with a smaller dose giving an order-of-magnitude higher resistivity.

Pulsed Neutron Powder Diffraction for Materials Science

NASA Astrophysics Data System (ADS)

Kamiyama, T.

2008-03-01

The accelerator-based neutron diffraction began in the end of 60's at Tohoku University which was succeeded by the four spallation neutron facilities with proton accelerators at the High Energy Accelerator Research Organization (Japan), Argonne National Laboratory and Los Alamos Laboratory (USA), and Rutherford Appleton Laboratory (UK). Since then, the next generation source has been pursued for 20 years, and 1MW-class spallation neutron sources will be appeared in about three years at the three parts of the world: Japan, UK and USA. The joint proton accelerator project (J-PARC), a collaborative project between KEK and JAEA, is one of them. The aim of the talk is to describe about J-PARC and the neutron diffractometers being installed at the materials and life science facility of J-PARC. The materials and life science facility of J-PARC has 23 neutron beam ports and will start delivering the first neutron beam of 25 Hz from 2008 May. Until now, more than 20 proposals have been reviewed by the review committee, and accepted proposal groups have started to get fund. Those proposals include five polycrystalline diffractometers: a super high resolution powder diffractometer (SHRPD), a 0.2%-resolution powder diffractometer of Ibaraki prefecture (IPD), an engineering diffractometers (Takumi), a high intensity S(Q) diffractometer (VSD), and a high-pressure dedicated diffractometer. SHRPD, Takumi and IPD are being designed and constructed by the joint team of KEK, JAEA and Ibaraki University, whose member are originally from the KEK powder group. These three instruments are expected to start in 2008. VSD is a super high intensity diffractometer with the highest resolution of Δd/d = 0.3%. VSD can measure rapid time-dependent phenomena of crystalline materials as well as glass, liquid and amorphous materials. The pair distribution function will be routinely obtained by the Fourier transiformation of S(Q) data. Q range of VSD will be as wide as 0.01 Å-1

The determination of the energy values and the composition analysis of M-16 rifle black powders

NASA Astrophysics Data System (ADS)

Satee, R.; Dararutana, P.; Phutdhawong, W.

2017-09-01

The determination of the energy values, specifically the heat of combustion of various M-16 black powders was the important part of the bullet efficiency investigations. The calorimetric bomb is commonly used for these determinations. Four M-16 black powders from the different sources were used as samples for this research. It was found that, after using calorimetric bomb technique, the gross heating value in Joules/g of sample S1-S4 were 10,647, 10,416, 5,281 and 3,878 respectively. The chemical compositions of carbon (C), hydrogen (H), nitrogen (N) and sulfer (S) have also been determined. The results indicated that carbon and nitrogen compositions of sample S1 shown the highest values and provided little differences with sample S2 while sample S3 and S4 shown the lowest carbon and nitrogen percentage composition. The hydrogen composition of all samples was equally valued, however, only sample 3 and 4 displayed sulfur values while no sulfur values were detected from sample 1 and 2. From these results, the heat values and chemical composition of M-16 black powders were characterized their sources and the energy values might be estimated from the amount of carbon and nitrogen in the black powders. Thus, it would be possible to use this determination analysis in the forensic investigation.

Flow Function of Pharmaceutical Powders Is Predominantly Governed by Cohesion, Not by Friction Coefficients.

PubMed

Leung, Lap Yin; Mao, Chen; Srivastava, Ishan; Du, Ping; Yang, Chia-Yi

2017-07-01

The purpose of this study was to demonstrate that the flow function (FFc) of pharmaceutical powders, as measured by rotational shear cell, is predominantly governed by cohesion but not friction coefficients. Driven by an earlier report showing an inverse correlation between FFc and the cohesion divided by the corresponding pre-consolidation stress (Wang et al. 2016. Powder Tech. 294:105-112), we performed analysis on a large data set containing 1130 measurements from a ring shear tester and identified a near-perfect inverse correlation between the FFc and cohesion. Conversely, no correlation was found between FFc and friction angles. We also conducted theoretical analysis and estimated such correlations based on Mohr-Coulomb failure model. We discovered that the correlation between FFc and cohesion can sustain as long as the angle of internal friction at incipient flow is not significantly larger than the angle of internal friction at steady-state flow, a condition covering almost all pharmaceutical powders. The outcome of this study bears significance in pharmaceutical development. Because the cohesion value is strongly influenced by the interparticle cohesive forces, this study effectively shows that it is more efficient to improve the pharmaceutical powder flow by lowering the interparticle cohesive forces than by lowering the interparticle frictions. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Characterization of Impact Initiation of Aluminum-Based Powder Compacts

NASA Astrophysics Data System (ADS)

Tucker, Michael; Dixon, Sean; Thadhani, Naresh

2011-06-01

Impact initiation of reactions in quasi-statically pressed powder compacts of Al-Ni, Al-Ta, and Al-W powder compacts is investigated in an effort to characterize the differences in the energy threshold as a function of materials system, volumetric distribution, and environment. The powder compacts were mounted in front of a copper projectile and impacted onto a steel anvil using a 7.62 mm gas gun at velocities up to 500 m/s. The experiments were conducted in ambient environment, as well as under a 50 millitorr vacuum. The IMACON 200 framing camera was used to observe the transient powder compact densification and deformation states, as well as a signature of reaction based on light emission. Evidence of reaction was also confirmed based on post-mortem XRD analysis of the recovered residue. The effective kinetic energy, dissipated in processes leading to reaction initiation was estimated and correlated with reactivity of the various compacts as a function of composition and environment.

Hot-melt extrusion microencapsulation of quercetin for taste-masking.

PubMed

Khor, Chia Miang; Ng, Wai Kiong; Kanaujia, Parijat; Chan, Kok Ping; Dong, Yuancai

2017-02-01

Besides its poor dissolution rate, the bitterness of quercetin also poses a challenge for further development. Using carnauba wax, shellac or zein as the shell-forming excipient, this work aimed to microencapsulate quercetin by hot-melt extrusion for taste-masking. In comparison with non-encapsulated quercetin, the microencapsulated powders exhibited significantly reduced dissolution in the simulated salivary pH 6.8 medium indicative of their potentially good taste-masking efficiency in the order of zein > carnauba wax > shellac. In vitro bitterness analysis by electronic tongue confirmed the good taste-masking efficiency of the microencapsulated powders. In vitro digestion results showed that carnauba wax and shellac-microencapsulated powders presented comparable dissolution rate with the pure quercetin in pH 1.0 (gastric) and 6.8 (intestine) medium; while zein-microencapsulated powders exhibited a remarkably slower dissolution rate. Crystallinity of quercetin was slightly reduced after microencapsulation while its chemical structure remained unchanged. Hot-melt extrusion microencapsulation could thus be an attractive technique to produce taste-masked bioactive powders.

Rietveld analysis using powder diffraction data with anomalous scattering effect obtained by focused beam flat sample method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, Masahiko, E-mail: masahiko@spring8.or.jp; Katsuya, Yoshio, E-mail: katsuya@spring8.or.jp; Sakata, Osami, E-mail: SAKATA.Osami@nims.go.jp

2016-07-27

Focused-beam flat-sample method (FFM) is a new trial for synchrotron powder diffraction method, which is a combination of beam focusing optics, flat shape powder sample and area detectors. The method has advantages for X-ray diffraction experiments applying anomalous scattering effect (anomalous diffraction), because of 1. Absorption correction without approximation, 2. High intensity X-rays of focused incident beams and high signal noise ratio of diffracted X-rays 3. Rapid data collection with area detectors. We applied the FFM to anomalous diffraction experiments and collected synchrotron X-ray powder diffraction data of CoFe{sub 2}O{sub 4} (inverse spinel structure) using X-rays near Fe K absorptionmore » edge, which can distinguish Co and Fe by anomalous scattering effect. We conducted Rietveld analyses with the obtained powder diffraction data and successfully determined the distribution of Co and Fe ions in CoFe{sub 2}O{sub 4} crystal structure.« less

Influence of Different Aluminum Sources on the NH3 Gas-Sensing Properties of ZnO Thin Films

NASA Astrophysics Data System (ADS)

Ozutok, Fatma; Karaduman, Irmak; Demiri, Sani; Acar, Selim

2018-02-01

Herein we report Al-doped ZnO films (AZO) deposited on the ZnO seed layer by chemical bath deposition method. Al powder, Al oxide and Al chloride were used as sources for the deposition process and investigated for their different effects on the NH3 gas-sensing performance. The morphological and microstructural properties were investigated by employing x-ray powder diffraction, scanning electron microscopy analysis and energy-dispersive x-ray spectroscopy. The characterization studies showed that the AZO thin films are crystalline and exhibit a hexagonal wurtzite structure. Ammonia (NH3) gas-sensing measurements of AZO films were performed at different concentration levels and different operation temperatures from 50°C to 210°C. The sample based on powder-Al source showed a higher response, selectivity and short response/recovery time than the remaining samples. The powder Al sample exhibited 33% response to 10-ppm ammonia gas at 190°C, confirming a strong dependence on the dopant source type.