JCPDS-ICDD Research Associateship (Cooperative Program with NBS/NIST)

PubMed Central

Wong-Ng, W.; McMurdie, H. F.; Hubbard, C. R.; Mighell, A. D.

2001-01-01

The Research Associateship program of the Joint Committee on Powder Diffraction-International Centre for Diffraction Data (JCPDS-ICDD, now known as the ICDD) at NBS/NIST was a long standing (over 35 years) successful industry-government cooperation. The main mission of the Associateship was to publish high quality x-ray reference patterns to be included in the Powder Diffraction File (PDF). The PDF is a continuing compilation of patterns gathered from many sources, compiled and published by the ICDD. As a result of this collaboration, more than 1500 high quality powder diffraction patterns, which have had a significant impact on the scientific community, were reported. In addition, various research collaborations with NBS/NIST also led to the development of several standard reference materials (SRMs) for instrument calibration and quantitative analyses, and computer software for data collection, calibration, reduction, for the editorial process of powder pattern publication, analysis of powder data, and for quantitative analyses. This article summarizes information concerning the JCPDS-ICDD organization, the Powder Diffraction File (PDF), history and accomplishments of the JCPDS-ICDD Research Associateship. PMID:27500061

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.

Micro Dot Patterning on the Light Guide Panel Using Powder Blasting.

PubMed

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

2008-02-08

This study is to develop a micromachining technology for a light guidepanel(LGP) mold, whereby micro dot patterns are formed on a LGP surface by a singleinjection process instead of existing screen printing processes. The micro powder blastingtechnique is applied to form micro dot patterns on the LGP mold surface. The optimalconditions for masking, laminating, exposure, and developing processes to form the microdot patterns are first experimentally investigated. A LGP mold with masked micro patternsis then machined using the micro powder blasting method and the machinability of themicro dot patterns is verified. A prototype LGP is test- injected using the developed LGPmold and a shape analysis of the patterns and performance testing of the injected LGP arecarried out. As an additional approach, matte finishing, a special surface treatment method,is applied to the mold surface to improve the light diffusion characteristics, uniformity andbrightness of the LGP. The results of this study show that the applied powder blastingmethod can be successfully used to manufacture LGPs with micro patterns by just singleinjection using the developed mold and thereby replace existing screen printing methods.

Micro Dot Patterning on the Light Guide Panel Using Powder Blasting

PubMed Central

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

2008-01-01

This study is to develop a micromachining technology for a light guide panel(LGP) mold, whereby micro dot patterns are formed on a LGP surface by a single injection process instead of existing screen printing processes. The micro powder blasting technique is applied to form micro dot patterns on the LGP mold surface. The optimal conditions for masking, laminating, exposure, and developing processes to form the micro dot patterns are first experimentally investigated. A LGP mold with masked micro patterns is then machined using the micro powder blasting method and the machinability of the micro dot patterns is verified. A prototype LGP is test- injected using the developed LGP mold and a shape analysis of the patterns and performance testing of the injected LGP are carried out. As an additional approach, matte finishing, a special surface treatment method, is applied to the mold surface to improve the light diffusion characteristics, uniformity and brightness of the LGP. The results of this study show that the applied powder blasting method can be successfully used to manufacture LGPs with micro patterns by just single injection using the developed mold and thereby replace existing screen printing methods. PMID:27879740

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

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.

Characterization of powdered fish heads for bone graft biomaterial applications.

PubMed

Oteyaka, Mustafa Ozgür; Unal, Hasan Hüseyin; Bilici, Namık; Taşçı, Eda

2013-01-01

The aim of this study was to define the chemical composition, morphology and crystallography of powdered fish heads of the species Argyrosomus regius for bone graft biomaterial applications. Two sizes of powder were prepared by different grinding methods; Powder A (coarse, d50=68.5 µm) and Powder B (fine, d50=19.1 µm). Samples were analyzed using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), thermogravimetry (TG), and energy dispersive X-ray spectroscopy (EDS). The powder was mainly composed of aragonite (CaCO3) and calcite (CaCO3). The XRD pattern of Powder A and B matched standard aragonite and calcite patterns. In addition, the calcium oxide (CaO) phase was found after the calcination of Powder A. Thermogravimetry analysis confirmed total mass losses of 43.6% and 47.3% in Powders A and B, respectively. The microstructure of Powder A was mainly composed of different sizes and tubular shape, whereas Powder B showed agglomerated particles. The high quantity of CaO and other oxides resemble the chemical composition of bone. In general, the powder can be considered as bone graft after transformation to hydroxyapatite phase.

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.

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%.

Cs{sup +} ion exchange kinetics in complex electrolyte solutions using hydrous crystalline silicotitanates

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

Gu, D.; Nguyen, L.; Philip, C.V.

1997-12-01

TAM-5 is a hydrous crystalline sodium silicotitanate inorganic ion exchanger with a high selectivity for Cs{sup +}. The kinetics of Cs{sup +}-Na{sup +} ion exchange using TAM-5 in multicomponent electrolyte solutions were determined using batch experiments. For the powder, which is composed of crystals, a single-phase, homogeneous model fit the data best. For the granules, which were prepared from the powder, a two-phase, heterogeneous model resulted in an excellent fit of the data. Macropore and crystal diffusivities were determined by fitting the model to experimental data collected on the powder and the granules. Intracrystalline diffusivities were concentration dependent and weremore » on the order of 10{sup {minus}19} m{sup 2}/s. Macropore diffusivities were on the order of 10{sup {minus}10} m{sup 2}/s. Resistance to diffusion in the macropores was not significant for granules with diameters less than 15 {micro}m. A two-phase, homogeneous model, where liquid within the pores is in equilibrium with the solid, was also evaluated for the granules. Surprisingly, for the granules, an excellent fit of the data was obtained; however, the effective macropore diffusivity was 1.1 {times} 10{sup {minus}11} m{sup 2}/s, an order of magnitude smaller than the macropore diffusivity found using the two-phase, heterogeneous model.« less

SMALL-ANGLE NEUTRON SCATTERING CHARACTERIZATION OF THE STRUCTURE OF NANOPOROUS CARBONS FOR ENERGY-RELATED APPLICATIONS

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

He, Lilin; Mavila Chathoth, Suresh; Melnichenko, Yuri B

2011-01-01

We used small-angle neutron scattering (SANS) and neutron contrast variation to study the structure of four nanoporouscarbons prepared by thermo-chemical etching of titanium carbide TiC in chlorine at 300, 400, 600, and 800 C with pore diameters ranging between -4 and -11 {angstrom}. SANS patterns were obtained from dry samples and samples saturated with deuterium oxide (D{sub 2}O) in order to delineate origin of the power law scattering in the low Q domain as well as to evaluate pore accessibility for D{sub 2}O molecules. SANS cross section of all samples was fitted to Debye-Anderson-Brumberger (DAB), DAB-Kirste-Porod models as well asmore » to the Guinier and modified Guinier formulae for cylindrical objects, which allowed for evaluating the radii of gyration as well as the radii and lengths of the pores under cylindrical shape approximation. SANS data from D{sub 2}O-saturated samples indicate that strong upturn in the low Q limit usually observed in the scattering patterns from microporous carbon powders is due to the scattering from outer surface of the powder particles. Micropores are only partially filled with D{sub 2}O molecules due to geometrical constraints and or partial hydrophobicity of the carbon matrix. Structural parameters of the dry carbons obtained using SANS are compared with the results of the gas sorption measurements and the values agree for carbide-derived carbons (CDCs) obtained at high chlorination temperatures (>600 C). For lower chlorination temperatures, pore radii obtained from gas sorption overestimate the actual pore size as calculated from SANS for two reasons: inaccessible small pores are present and the model-dependent fitting based on density functional theory models assumes non-spherical pores, whereas SANS clearly indicates that the pore shape in microporous CDC obtained at low chlorination temperatures is nearly spherical.« less

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.

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

Comparative study of particle structure evolution during water sorption: skim and whole milk powders.

PubMed

Murrieta-Pazos, I; Gaiani, C; Galet, L; Cuq, B; Desobry, S; Scher, J

2011-10-01

Surface composition of dairy powders influences significantly a quantity of functional properties such as rehydration, caking, agglomeration. Nevertheless, the kinetic of water uptake by the powders was never directly related to the structure and the composition of the surface. In this work, the effect of relative humidity on the structural reorganization of two types of dairy powder was studied. The water-powder interaction for industrial whole milk powder, and skim milk powder was studied using dynamic vapor sorption. The water sorption isotherms were fitted with a Brunner-Emmet-Teller model and each stage of the sorption curve was analyzed with a Fickian diffusion. The water content in the monolayer predicted for each powder and the moisture diffusivity calculated were discussed and compared. Concurrently, powders microstructure and powders surface under variable relative humidity were assessed by X-ray photoelectron spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray and atomic force microscopy. A correlation between the data obtained from the sorption isotherms and the modifications of structure allowed us to conclude that powder microstructure and chemical state of the components could play an important role in determining the water diffusivity. Copyright © 2011 Elsevier B.V. All rights reserved.

Design and characterization of a mapping device optimized to collect XRD patterns from highly inhomogeneous and low density powder samples

NASA Astrophysics Data System (ADS)

D'Elia, A.; Cibin, G.; Robbins, P. E.; Maggi, V.; Marcelli, A.

2017-11-01

We report on the development of a device designed to improve X-ray Powder Diffraction data acquisition through mapping coupled to a rotational motion of the sample. The device and procedures developed aim at overcoming the experimental issues that accompany the analysis of inhomogeneous samples, such as powders, dust or aerosols deposited on a flat substrate. Introducing the mapping of the substrate on which powders are deposited and at the same time the rotation, we may overcome drawbacks associated to inhomogeneous distributions such as ring-like patterns due to the coffee stain effect generated by the evaporation of a solution. Experimental data have been collected from powders of a NIST standard soil sample (11 μg) and from an airborne dust extracted from deep ice cores in Antarctica (9.6 μg). Both particulate samples have been deposited on polycarbonate membranes from ultra-dilute solutions. Data show that this approach makes possible to collect XRD patterns useful to identify mineral fractions present in these low density samples.

Tap density equations of granular powders based on the rate process theory and the free volume concept.

PubMed

Hao, Tian

2015-02-28

The tap density of a granular powder is often linked to the flowability via the Carr index that measures how tight a powder can be packed, under an assumption that more easily packed powders usually flow poorly. Understanding how particles are packed is important for revealing why a powder flows better than others. There are two types of empirical equations that were proposed to fit the experimental data of packing fractions vs. numbers of taps in the literature: the inverse logarithmic and the stretched exponential. Using the rate process theory and the free volume concept under the assumption that particles will obey similar thermodynamic laws during the tapping process if the "granular temperature" is defined in a different way, we obtain the tap density equations, and they are reducible to the two empirical equations currently widely used in literature. Our equations could potentially fit experimental data better with an additional adjustable parameter. The tapping amplitude and frequency, the weight of the granular materials, and the environmental temperature are grouped into this parameter that weighs the pace of the packing process. The current results, in conjunction with our previous findings, may imply that both "dry" (granular) and "wet" (colloidal and polymeric) particle systems are governed by the same physical mechanisms in term of the role of the free volume and how particles behave (a rate controlled process).

New nano-sized Al2O3-BN coating 3Y-TZP ceramic composites for CAD/CAM-produced all-ceramic dental restorations. Part I. Fabrication of powders.

PubMed

Yang, Se Fei; Yang, Li Qiang; Jin, Zhi Hao; Guo, Tian Wen; Wang, Lei; Liu, Hong Chen

2009-06-01

Partially sintered 3 mol % yttria-stabilized tetragonal zirconium dioxide (ZrO(2), zirconia) polycrystal (3Y-TZP) ceramics are used in dental posterior restorations with computer-aided design-computer-aided manufacturing (CAD/CAM) techniques. High strength is acquired after sintering, but shape distortion of preshaped compacts during their sintering is inevitable. The aim of this study is to fabricate new machinable ceramic composites with strong mechanical properties that are fit for all-ceramic dental restorations. Aluminum oxide (Al(2)O(3))-coated 3Y-TZP powders were first prepared by the heterogeneous precipitation method starting with 3Y-TZP, Al(NO(3))(3) . 9H(2)O, and ammonia, then amorphous boron nitride (BN) was produced and the as-received composite powders were coated via in situ reaction with boric acid and urea. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to analyze the status of Al(2)O(3)-BN on the surface of the 3Y-TZP particles. TEM micrographs show an abundance of Al(2)O(3) particles and amorphous BN appearing uniformly on the surface of the 3Y-TZP particles after the coating process. The size of the Al(2)O(3) particles is about 20 nm. The XRD pattern shows clearly the peak of amorphous BN among the peaks of ZrO(2).

Free flowing and cohesive powders agitation in a cylindrical convective blender- kinetics experiments and Markov chain modelling

NASA Astrophysics Data System (ADS)

Legoix, Léonard; Milhé, Mathieu; Gatumel, Cendrine; Berthiaux, Henri

2017-06-01

An original methodology for studying powder flow in a cylindrical convective blender has been developed. A free-flowing and a cohesive powder were studied, at a fixed stirring speed, in rolling regime. For both powders, three apparent flow mechanisms were evidenced: convection in the volume swept by the blades, diffusion/shearing between the agitated zone and the stagnant one, as well as in the stagnant zone itself, and avalanches at the powder bed surface between agitated and stagnant zones. After defining six zones in the blender, tracing experiments were carried out by placing appropriate tracers in different starting zones and sampling the whole bed at different stirring times, which lead to mixing kinetics of the powders into themselves. A Markov chains model of the blender allowed the quantification of the three mechanisms respective magnitude by fitting the experimental data. This simple model has a good agreement with the free-flowing powder data, but is not able to represent well the observations for the cohesive powder. Bed consolidation should probably be taken into account for this kind of powders and thus a linear Markov model is not sufficient.

Prediction of the Effective Thermal Conductivity of Powder Insulation

NASA Astrophysics Data System (ADS)

Jin, Lingxue; Park, Jiho; Lee, Cheonkyu; Jeong, Sangkwon

The powder insulation method is widely used in structural and cryogenic systems such as transportation and storage tanks of cryogenic fluids. The powder insulation layer is constructed by small particle powder with light weight and some residual gas with high porosity. So far, many experiments have been carried out to test the thermal performance of various kinds of powder, including expanded perlite, glass microspheres, expanded polystyrene (EPS). However, it is still difficult to predict the thermal performance of powder insulation by calculation due to the complicated geometries, including various particle shapes, wide powder diameter distribution, and various pore sizes. In this paper, the effective thermal conductivity of powder insulation has been predicted based on an effective thermal conductivity calculationmodel of porous packed beds. The calculation methodology was applied to the insulation system with expanded perlite, glass microspheres and EPS beads at cryogenic temperature and various vacuum pressures. The calculation results were compared with previous experimental data. Moreover, additional tests were carried out at cryogenic temperature in this research. The fitting equations of the deformation factor of the area-contact model are presented for various powders. The calculation results show agood agreement with the experimental results.

Development and characterization of a new encapsulating agent from orange juice by-products.

PubMed

Kaderides, Kyriakos; Goula, Athanasia M

2017-10-01

The replacement of maltodextrins as carriers for the spray drying of sticky and sugar based bioactives is an important development for the food industry. In this work, orange juice industry by-product was used to obtain a high dietary fiber powder to be used as carrier material. This powder was characterized with respect to its physical and chemical properties related to the process of encapsulation by spray drying. Adsorption isotherms of orange waste powder were determined at 30, 45, and 60°C. The data were fitted to several models including two-parameter (BET, Halsey, Smith, and Oswin), three-parameter (GAB), and four-parameter (Peleg) relationships. The GAB model best fitted the experimental data. The isosteric heat of sorption was determined from the equilibrium sorption data using the Clausius-Clapeyron equation. Isosteric heats of sorption were found to decrease exponentially with increasing moisture content. The enthalpy-entropy compensation theory was applied to the sorption isotherms and indicated an enthalpy controlled sorption process. Glass transition temperatures (T g ) of orange waste powder conditioned at various water activities were determined and a strong plasticizing effect of water on T g was found. These data were satisfactory correlated by the Gordon and Taylor model. The critical water activity and moisture content for the orange waste powder were 0.82 and 0.18g water/g solids, respectively, at a storage temperature of 25°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cold Spray for Repair of Magnesium Components

DTIC Science & Technology

2011-11-01

powder material. Other advantages of the Cold Spray process include:  It provides extremely dense coatings with virtually no inclusions or cracks ... crack on insertion of Rosan fitting and does not reclaim the mechanical properties of the Mg alloy. It is expected that the use of Cold Spray coating...Spray process include:  Extremely dense coatings with virtually no inclusions or cracks .  Retains properties and microstructure of initial powder

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

The Application of Globular Water-Atomized Iron Powders for Additive Manufacturing by a LENS Technique.

PubMed

Durejko, Tomasz; Aniszewska, Justyna; Ziętala, Michał; Antolak-Dudka, Anna; Czujko, Tomasz; Varin, Robert A; Paserin, Vlad

2018-05-18

The water-atomized ATOMET 28, 1001, 4701, and 4801 powders, manufactured by Rio Tinto Metal Powders, were used for additive manufacturing by a laser engineered net shaping (LENS) technique. Their overall morphology was globular and rounded with a size distribution from about 20 to 200 µm. Only the ATOMET 28 powder was characterized by a strong inhomogeneity of particle size and irregular polyhedral shape of powder particles with sharp edges. The powders were pre-sieved to a size distribution from 40 to 150 µm before LENS processing. One particular sample-LENS-fabricated from the ATOMET 28 powder-was characterized by the largest cross-sectional (2D) porosity of 4.2% and bulk porosity of 3.9%, the latter determined by microtomography measurements. In contrast, the cross-sectional porosities of bulk, solid, nearly cubic LENS-fabricated samples from the other ATOMET powders exhibited very low porosities within the range 0.03⁻0.1%. Unexpectedly, the solid sample-LENS-fabricated from the reference, a purely spherical Fe 99.8 powder-exhibited a porosity of 1.1%, the second largest after that of the pre-sieved, nonspherical ATOMET 28 powder. Vibrations incorporated mechanically into the LENS powder feeding system substantially improved the flow rate vs. feeding rate dependence, making it completely linear with an excellent coefficient of fit, R² = 0.99. In comparison, the reference powder Fe 99.8 always exhibited a linear dependence of the powder flow rate vs. feeding rate, regardless of vibrations.

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

Formation of polycrystalline MgB2 synthesized by powder in sealed tube method with different initial boron phase

NASA Astrophysics Data System (ADS)

Yudanto, Sigit Dwi; Imaduddin, Agung; Kurniawan, Budhy; Manaf, Azwar

2018-04-01

Magnesium diboride, MgB2 is a new high critical temperature superconductor that discovered in the beginning of the 21st century. The MgB2 has a simple crystal structure and a high critical temperature, which can be manufactured in several forms like thin films, tapes, wires including bulk in the large scale. For that reason, the MgB2 has good prospects for various applications in the field of electronic devices. In the current work, we have explored the synthesis of MgB2 polycrystalline using powder in a sealed tube method. Different initial boron phase for the synthesized of MgB2 polycrystalline were used. These were, in addition to magnesium powders, crystalline boron, amorphous boron and combination both of them were respectively fitted in the synthesis. The raw materials were mixed in a stoichiometric ratio of Mg: B=1:2, ground using agate mortar, packed into stainless steel SS304. The pack was then sintered at temperature of 800°C for 2 hours in air atmosphere. Phase formation of MgB2 polycrystalline in difference of initial boron phase was characterized using XRD and SEM. Referring to the diffraction pattern and microstructure observation, MgB2 polycrystalline was formed, and the formation was effective when using the crystalline Mg and fully amorphous B as the raw materials. The critical temperature of the specimen was evaluated by the cryogenic magnet. The transition temperature of the MgB2 specimen synthesized using crystalline magnesium and full amorphous boron is 42.678 K (ΔTc = 0.877 K).

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.

The Application of Globular Water-Atomized Iron Powders for Additive Manufacturing by a LENS Technique

PubMed Central

Ziętala, Michał; Antolak-Dudka, Anna; Paserin, Vlad

2018-01-01

The water-atomized ATOMET 28, 1001, 4701, and 4801 powders, manufactured by Rio Tinto Metal Powders, were used for additive manufacturing by a laser engineered net shaping (LENS) technique. Their overall morphology was globular and rounded with a size distribution from about 20 to 200 µm. Only the ATOMET 28 powder was characterized by a strong inhomogeneity of particle size and irregular polyhedral shape of powder particles with sharp edges. The powders were pre-sieved to a size distribution from 40 to 150 µm before LENS processing. One particular sample—LENS-fabricated from the ATOMET 28 powder—was characterized by the largest cross-sectional (2D) porosity of 4.2% and bulk porosity of 3.9%, the latter determined by microtomography measurements. In contrast, the cross-sectional porosities of bulk, solid, nearly cubic LENS-fabricated samples from the other ATOMET powders exhibited very low porosities within the range 0.03–0.1%. Unexpectedly, the solid sample—LENS-fabricated from the reference, a purely spherical Fe 99.8 powder—exhibited a porosity of 1.1%, the second largest after that of the pre-sieved, nonspherical ATOMET 28 powder. Vibrations incorporated mechanically into the LENS powder feeding system substantially improved the flow rate vs. feeding rate dependence, making it completely linear with an excellent coefficient of fit, R2 = 0.99. In comparison, the reference powder Fe 99.8 always exhibited a linear dependence of the powder flow rate vs. feeding rate, regardless of vibrations. PMID:29783704

Structural and magnetic properties of FeCoC system obtained by mechanical alloying

NASA Astrophysics Data System (ADS)

Rincón Soler, A. I.; Rodríguez Jacobo, R. R.; Medina Barreto, M. H.; Cruz-Muñoz, B.

2017-11-01

Fe96-XCoXC4 (x = 0, 10, 20, 30, 40 at. %) alloys were obtained by mechanical alloying of Fe, C and Co powders using high-energy milling. The structural and magnetic properties of the alloy system were analyzed by X-ray diffraction, Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM) and Mössbauer Spectrometry at room temperature. The X-ray diffraction patterns showed a BCC-FeCoC structure phase for all samples, as well as a lattice parameter that slightly decreases with Co content. The saturation magnetization and coercive field were analyzed as a function of Co content. The Mössbauer spectra were fitted with a hyperfine magnetic field distribution showing the ferromagnetic behavior and the disordered character of the samples. The mean hyperfine magnetic field remained nearly constant (358 T) with Co content.

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.

Mineral and Geochemical Classification From Spectroscopy/Diffraction Through Neural Networks

NASA Astrophysics Data System (ADS)

Ferralis, N.; Grossman, J.; Summons, R. E.

2017-12-01

Spectroscopy and diffraction techniques are essential for understanding structural, chemical and functional properties of geological materials for Earth and Planetary Sciences. Beyond data collection, quantitative insight relies on experimentally assembled, or computationally derived spectra. Inference on the geochemical or geophysical properties (such as crystallographic order, chemical functionality, elemental composition, etc.) of a particular geological material (mineral, organic matter, etc.) is based on fitting unknown spectra and comparing the fit with consolidated databases. The complexity of fitting highly convoluted spectra, often limits the ability to infer geochemical characteristics, and limits the throughput for extensive datasets. With the emergence of heuristic approaches to pattern recognitions though machine learning, in this work we investigate the possibility and potential of using supervised neural networks trained on available public spectroscopic database to directly infer geochemical parameters from unknown spectra. Using Raman, infrared spectroscopy and powder x-ray diffraction from the publicly available RRUFF database, we train neural network models to classify mineral and organic compounds (pure or mixtures) based on crystallographic structure from diffraction, chemical functionality, elemental composition and bonding from spectroscopy. As expected, the accuracy of the inference is strongly dependent on the quality and extent of the training data. We will identify a series of requirements and guidelines for the training dataset needed to achieve consistent high accuracy inference, along with methods to compensate for limited of data.

The thermal expansion of anhydrite to 1000° C

USGS Publications Warehouse

Evans, Howard T.

1979-01-01

The thermal expansion of anhydrite, CaSO4, has been measured from 22° to 1,000° C by X-ray diffraction, using the Guinier-Lenné heating powder camera. The heating patterns were calibrated with Guinier-Hägg patterns at 25° C, using quartz as internal standard. Heating experiments were run on natural anhydrite (Bancroft, Ontario), which at room temperature has lattice constants in close agreement with those of synthetic material. The orthorhombic unit cell at 22° C (space groupAmma) has a=7.003 (1) Å, b=6.996 (2) Å and c=6.242 (1) Å, V=305.9 (2) Å3. At room temperature, the thermal expansion coefficients α and β (α in °C−1×104, β in °C−2×108) are for a, 0.10, −0.69; forb, 0.08, 0.19; for c, 0.18, 1.60; for V, 0.37, 1.14. Second-order coefficients provide an excellent fit over the whole range to 1,000° C.

Influence of scanner, powder application, and adjustments on CAD-CAM crown misfit.

PubMed

Prudente, Marcel S; Davi, Letícia R; Nabbout, Kemilly O; Prado, Célio J; Pereira, Leandro M; Zancopé, Karla; Neves, Flávio D

2018-03-01

The manufacturers of computer-aided design and computer-aided manufacturing (CAD-CAM) systems emphasize that new technologies can improve the marginal fit of dental crowns. However, data supporting this claim are limited. The purpose of this in vitro study was to investigate the differences among the following fabrication methods on the marginal discrepancy of dental crowns: intraoral optical scanners, powder application, and adjustments of intaglio surface. A single human premolar was fixed on a typodont and prepared to receive crowns prepared by the CEREC CAD-CAM system. Three fabrication techniques were used: digital scans using the CEREC Bluecam scanner with titanium dioxide powder (TDP), digital scans using the CEREC Omnicam scanner without TDP, and digital scans using the Omnicam scanner with TDP. Five experimental groups (n=10) were designated: Bluecam (group B), Bluecam with adjustments (group BA), Omnicam (group O), Omnicam with adjustments (group OA), and Omnicam with TDP (group OP). The specimens were scanned using microcomputed tomography to measure the vertical, horizontal, and internal fit and volumetric 3-dimensional (3D) internal fit values of each luting space. The paired t test was used to evaluate mean marginal fit change after adjustments within the same group. One-way analysis of variance and post hoc tests were used to compare groups B, O, and OP (α=.05). Mean vertical fit values ±standard deviations of group B=29.5 ±13.2 μm; BA=26.9 ±7.7 μm; O=149.4 ±64.4 μm; OA=49.4 ±12.7 μm; and OP=33.0 ±8.3 μm. Adjustments in the intaglio surface and TDP application statistically influenced the vertical fit of group O (P<.001). The percentage of vertical fit values <75 μm in group B=89.3%, BA=92.7%, O=31.0%, OA=73.5%, and OP=92.0%. Mean horizontal fit values for group B=56.2 ±21.5 μm; 85.8 ±44.4 μm for group BA; 77.5 ±11.8 μm for group O; 102.5 ±16.2 μm for group OA; and 91.4 ±19.4 μm for group OP. Results from group B were significantly different from those of the other test groups (P<.05). The percentages of horizontal misfit were 61.2% in group B; 73.5% in group BA; 88.1% in group O; 92.4% in group OA; and 85.0% in group OP. Volumetric 3D internal fit values in group B were 9.4 ±1.3 mm 3 ; 10.7 ±1.0 mm 3 in group BA; 11.8 ±2.1 mm 3 in group O; 11.0 ±1.3 mm 3 in group OA; and 9.6 ±0.9 mm 3 in group OP. The overall results from groups B and OP were better than those of group O, with regard to vertical misfit and volumetric 3D internal fit. Different intraoral optical scanners, powder application, and internal adjustments influenced the marginal discrepancy of crowns. Crowns fabricated using the Omnicam system had significantly higher vertical discrepancy and volumetric 3D internal fit than those fabricated using the Bluecam scanner with TDP. Adjustments of the intaglio surface improved the vertical fit of crowns made using the Omnicam scanner; however, TDP application before Omnicam scanning improved the vertical fit as well as the volumetric 3D internal fit value of the luting space of crowns. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

NanoClusters Enhance Drug Delivery in Mechanical Ventilation

NASA Astrophysics Data System (ADS)

Pornputtapitak, Warangkana

The overall goal of this thesis was to develop a dry powder delivery system for patients on mechanical ventilation. The studies were divided into two parts: the formulation development and the device design. The pulmonary system is an attractive route for drug delivery since the lungs have a large accessible surface area for treatment or drug absorption. For ventilated patients, inhaled drugs have to successfully navigate ventilator tubing and an endotracheal tube. Agglomerates of drug nanoparticles (also known as 'NanoClusters') are fine dry powder aerosols that were hypothesized to enable drug delivery through ventilator circuits. This Thesis systematically investigated formulations of NanoClusters and their aerosol performance in a conventional inhaler and a device designed for use during mechanical ventilation. These engineered powders of budesonide (NC-Bud) were delivered via a MonodoseRTM inhaler or a novel device through commercial endotracheal tubes, and analyzed by cascade impaction. NC-Bud had a higher efficiency of aerosol delivery compared to micronized stock budesonide. The delivery efficiency was independent of ventilator parameters such as inspiration patterns, inspiration volumes, and inspiration flow rates. A novel device designed to fit directly to the ventilator and endotracheal tubing connections and the MonodoseRTM inhaler showed the same efficiency of drug delivery. The new device combined with NanoCluster formulation technology, therefore, allowed convenient and efficient drug delivery through endotracheal tubes. Furthermore, itraconazole (ITZ), a triazole antifungal agent, was formulated as a NanoCluster powder via milling (top-down process) or precipitation (bottom-up process) without using any excipients. ITZ NanoClusters prepared by wet milling showed better aerosol performance compared to micronized stock ITZ and ITZ NanoClusters prepared by precipitation. ITZ NanoClusters prepared by precipitation methods also showed an amorphous state while milled ITZ NanoClusters maintained the crystalline character. Overall, NanoClusters prepared by various processes represent a potential engineered drug particle approach for inhalation therapy since they provide effective aerosol properties and stability due to the crystalline state of the drug powders. Future work will continue to explore formulation and delivery performance in vitro and in vivo..

Dietary Patterns and Fitness Level in Mexican Teenagers.

PubMed

Estrada-Reyes, César; Tlatempa-Sotelo, Patricia; Valdés-Ramos, Roxana; Cabañas-Armesilla, María; Manjarrez-Montes-de-Oca, Rafael

2018-01-01

Nowadays, the term "physical fitness" has evolved from sports performance to health status, and it has been considered a strong predictor of cardiovascular disease. In this sense, test batteries have been developed to evaluate physical fitness such as the ALPHA-FIT battery. On the other hand, the analysis of dietary patterns has emerged as an alternative method to study the relationship between diet and chronic noncommunicable diseases. However, the association between dietary patterns and the physical fitness level has not been evaluated in both adults and adolescents. This association is most important in adolescents due to the fact that establishing healthy dietary behaviors and a favorable nutritional profile in early stages of life prevents various chronic-degenerative diseases. To analyze the association between dietary patterns and the level of fitness in Mexican teenagers. We analyzed the relationship between dietary patterns and the fitness level of 42 teenage students in Toluca, Mexico. Students were weighed and measured, and their food intake was recorded for 2 weekdays and one weekend day. Dietary patterns were obtained by factorial analysis. The ALPHA-FIT battery was used to measure the fitness level. Fifty percent of the students were found to have a low fitness level (62.1% men; 37.9% women). There was no association ( X 2 = 0.83) between the dietary patterns "high in fat and sugar," "high in protein", and "low in fat and protein" and the level of physical condition in teens. In this study, all of teenagers with a very low level of fitness obtained a high dietary pattern in protein; however, 40% with a high level of physical condition resulted in the same pattern; that is why we did not find a relationship between the fitness level and the patterns investigated in this study.

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

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.

Determination of the Sensibility Factors for TLD-100 Powder on the Energy of X-Ray of 50, 250 kVp; 192Ir, 137Cs and 60Co

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

Loaiza, Sandra P.; Alvarez, Jose T.

2006-09-08

TLD-100 powder is calibrated in terms of absorbed dose to water Dw, using the protocols AAPM TG61, AAPM TG43 and IAEA-TRS 398, for the energy of RX 50, 250 kVp, 137Cs and 60Co respectively. The calibration curves, TLD Response R versus Dw, are fitted by weighted least square by a quadratic polynomials; which are validated with the lack of fit and the Anderson-Darling normality test. The slope of these curves corresponds to the sensibility factor: Fs R/DW, [Fs] = nC Gy-1. The expanded uncertainties U's for these factors are obtained from the ANOVA tables. Later, the Fs' values are interpolatedmore » using the effective energy hvefec for the 192Ir. The SSDL sent a set of capsules with powder TLD-100 for two Hospitals. These irradiated them a nominal dose of Dw = 2 Gy. The results determined at SSDL are: for the Hospital A the Dw is overestimated in order to 4.8% and the Hospital B underestimates it in the range from -1.4% to -17.5%.« less

High-resolution neutron diffraction study of microstructural changes in nanocrystalline ball-milled niobium carbide NbC{sub 0.93}

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

Balagurov, Anatoly M.; Bobrikov, Ivan A.; Bokuchava, Gizo D.

2015-11-15

High resolution neutron diffraction was applied for elucidating of the microstructural evolution of nanocrystalline niobium carbide NbC{sub 0.93} powders subjected to high-energy ball milling. The diffraction patterns were collected with the high resolution Fourier diffractometer HRFD by using the reverse time-of-flight (RTOF) mode of data acquisition. The traditional single diffraction line analysis, the Rietveld method and more advanced Whole Powder Pattern Modeling technique were applied for the data analysis. The comparison of these techniques was performed. It is established that short-time milling produces a non-uniform powder, in which two distinct fractions with differing microstructure can be identified. Part of themore » material is in fact milled efficiently, with a reduction in grain size, an increase in the quantity of defects, and a corresponding tendency to decarburize reaching a composition NbC{sub 0.80} after 15 h of milling. The rest of the powder is less efficiently processed and preserves its composition and lower defect content. Larger milling times should have homogenized the system by increasing the efficiently milled fraction, but the material is unable to reach a uniform and homogeneous state. It is definitely shown that RTOF neutron diffraction patterns can provide the very accurate data for microstructure analysis of nanocrystalline powders. - Highlights: • The NbC{sub 0.93} powder was processed by high-energy ball milling. • The microstrain and dislocation density increase with milling time increase. • The corresponding decrease in crystallite size with milling time was observed. • The material exhibits the presence of two fractions after ball milling. • The RTOF neutron diffraction data are suitable for accurate microstructure analysis.« less

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)

Biosorption of praseodymium (III) using Terminalia arjuna bark powder in batch systems: isotherm and kinetic studies.

PubMed

Swain, Krishna Kumari; Mishra, Pravat Manjari; Devi, Aparna Prabha

2018-02-01

The high demand for rare earth elements (REEs) used in various advanced materials implies demand for increased production of REEs or the recycling of solutions to recover the REEs they contain. In this study, the biosorption of Pr(III) from aqueous solution by bark powder of Terminalia arjuna was examined in a batch system as a function of metal concentration, biosorbent dosage, pH and contact time. Results showed that T. arjuna bark powder has a high affinity for adsorbing Pr(III): more than 90% at pH 6.63. The adsorption of Pr(III) by T. arjuna bark powder was investigated by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The kinetics of the biosorption process was tested with pseudo-first-order and pseudo-second-order models, and the results showed that the biosorption process was better fitted to the pseudo-second-order model. From Fourier transform infrared spectroscopy (FT-IR) analysis, it is confirmed that the biomolecules of T. arjuna bark powder are involved in the biosorption process of Pr(III) metal ions.

Electron density distribution and disordered crystal structure of 15R-SiAlON, SiAl{sub 4}O{sub 2}N{sub 4}

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

Banno, Hiroki; Hanai, Takaaki; Asaka, Toru

2014-03-15

The crystal structure of SiAl{sub 4}O{sub 2}N{sub 4} was characterized by laboratory X-ray powder diffraction (CuKα{sub 1}). The title compound is trigonal with space group R3-bar m. The hexagonal unit-cell dimensions (Z=3) are a=0.301332(3) nm, c=4.18616(4) nm and V=0.3291825(5) nm{sup 3}. The initial structural model was successfully derived by the charge-flipping method and further refined by the Rietveld method. The final structural model showed the positional disordering of one of the three (Si,Al) sites. The maximum-entropy method-based pattern fitting (MPF) method was used to confirm the validity of the split-atom model, in which conventional structure bias caused by assuming intensitymore » partitioning was minimized. The reliability indices calculated from the MPF were R{sub wp}=5.05%, S (=R{sub wp}/R{sub e})=1.21, R{sub p}=3.77%, R{sub B}=1.29% and R{sub F}=1.01%. The disordered crystal structure was successfully described by overlapping three types of domains with ordered atom arrangements. The distribution of atomic positions in one of the three types of domains can be achieved in the space group R3-bar m. The atom arrangements in the other two types of domains are noncentrosymmetrical with the space group R3m. These two structural configurations are related by the pseudo-symmetry inversion. -- Graphical abstract: A bird's eye view of electron densities up to 75.3% (0.133 nm{sup −3}) of the maximum on the plane parallel to (110) with the corresponding atomic arrangements of SiAl{sub 4}O{sub 2}N{sub 4}. Highlights: • Crystal structure of SiAl{sub 4}O{sub 2}N{sub 4} is determined by laboratory X-ray powder diffraction. • The atom arrangements are represented by the split-atom model. • The maximum-entropy method-based pattern fitting method is used to confirm the validity of the model. • The disordered structure is described by overlapping three types of domains with ordered atom arrangements.« less

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

Water hyacinth: a possible alternative rate retarding natural polymer used in sustained release tablet design

PubMed Central

Khatun, Sabera; Sutradhar, Kumar B.

2014-01-01

In recent years natural polymers have been widely used because of their effectiveness and availability over synthetic polymers. In this present investigation matrix tablets of Metformin hydrochloride were formulated using Water hyacinth powder and its rate retardant activity was studied. Tablets were prepared using wet granulation method with 8% starch as granulating agent and 5, 10, 15, 20, 25 and 30% of Water hyacinth powder to the drug. In preformulation study, angle of repose, Carr's Index and Hausner ratio were calculated. Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM) studies were performed and no interactions were found between drug and excipients. Weight variation, friability, hardness, thickness, diameter, and in vitro release study were performed with the prepared matrix tablets. Dissolution studies were conducted using USP type II apparatus at a speed of 100 rpm at 37°C ± 0.5 temperature for 8 h. Though all the formulations comply with both BP and USP requirements, formulation F-1 (5% of Water hyacinth) was the best fitted formula. The drug release patterns were explained in different kinetic models such as Zero order, First order, Higuchi, Hixson Crowell, and Korsmeyer-Peppas equations. The current investigation implies that Water hyacinth has the potential to be used as a rate-retarding agent in sustained release drug formulations. PMID:24966835

Removal of Malachite Green Dye by Mangifera indica Seed Kernel Powder

NASA Astrophysics Data System (ADS)

Singh, Dilbagh; Sowmya, V.; Abinandan, S.; Shanthakumar, S.

2017-11-01

In this study, batch experiments were carried out to study the adsorption of Malachite green dye from aqueous solution by Mangifera indica (mango) seed kernel powder. The mango seed kernel powder was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Effect of various parameters including pH, contact time, adsorbent dosage, initial dye concentration and temperature on adsorption capacity of the adsorbent was observed and the optimized condition for maximum dye removal was identified. Maximum percentage removal of 96% was achieved with an adsorption capacity of 22.8 mg/g at pH 6 with an initial concentration of 100 mg/l. The equilibrium data were examined to fit the Langmuir and Freundlich isotherm models. Thermodynamic parameters for the adsorption process were also calculated.

Improved L-C resonant decay technique for Q measurement of quasilinear power inductors: New results for MPP and ferrite powdered cores

NASA Technical Reports Server (NTRS)

Niedra, Janis M.; Gerber, Scott S.

1995-01-01

The L-C resonant decay technique for measuring circuit Q or losses is improved by eliminating the switch from the inductor-capacitor loop. A MOSFET switch is used instead to momentarily connect the resonant circuit to an existing voltage source, which itself is gated off during the decay transient. Very reproducible, low duty cycle data could be taken this way over a dynamic voltage range of at least 10:1. Circuit Q is computed from a polynomial fit to the sequence of the decaying voltage maxima. This method was applied to measure the losses at 60 kHz in inductors having loose powder cores of moly permalloy and an Mn-Zn power ferrite. After the copper and capacitor losses are separated out, the resulting specific core loss is shown to be roughly as expected for the MPP powder, but anomalously high for the ferrite powder. Possible causes are mentioned.

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.

Analysis of Short and Long Range Atomic Order in Nanocrystalline Diamonds with Application of Powder Diffractometry

NASA Technical Reports Server (NTRS)

Palosz, B.; Grzanka, E.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Neuefiend, J.; Weber, H.-P.; Proffen, T.; VonDreele, R.; Palosz, W.;

Effect of acidity on the citrate-nitrate combustion synthesis of alumina-zirconia composite powder

NASA Astrophysics Data System (ADS)

Chandradass, J.; Kim, Ki Hyeon

2009-12-01

Alumina-zirconia composite powders were produced by sol-gel autocombustion. 20 wt.% ZrO2-Al2O3 mixture precursor solutions were chelated by citric acid ions at different pH. DTA analysis shows sluggish decomposition at low pH, whereas there was rapid decomposition at high pH = 9. XRD patterns of the calcined powders showed that well crystallized powder with 100 % tetragonal phase and α-alumina phase is produced when pH = 0.58 (without ammonia addition). TEM characterization of composite powders revealed homogenous distribution of nanosized zirconia particles in the alumina matrix. FTIR analysis shows peaks at 590 cm-1 and 454 cm-1, which are identified as the characteristic absorption bands of Zr-O and Al-O.

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.

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.

Particle characteristics and lung deposition patterns in a human airway replica of a dry powder formulation of polylactic acid produced using supercritical fluid technology.

PubMed

Cheng, Y S; Yazzie, D; Gao, J; Muggli, D; Etter, J; Rosenthal, G J

2003-01-01

Polylactic acid (PLA) powders have been used as vector particles to carry pharmaceutical material. Drugs incorporated in the PLA powder can be retained in the lung for a longer period and may be more effective than free-form drugs. A new formulation of L-PLA dry powder, which was easy to disperse in the air, was produced by using a supercritical technology. The L-PLA powder was characterized in terms of physical particle size and aerodynamic size as generated with a Turbuhaler dry powder inhaler (DPI). Electron microscopy analysis of the particles indicated that they were individual particles in bulk form and became aggregate particles after generation by the Turbuhaler. Aerodynamic particle size analysis using both an Aerodynamic Particle Sizer (APS) aerosol spectrometer and Andersen impactor showed that the aerodynamic size decreased as the flow rate in the Turbuhaler increased from 28.3 to 90 L min(-1). Deposition patterns in the human respiratory tract were estimated using a realistic physical replica of human airways. Deposition of the L-PLA was high (80.8%) in the oral airway at 28.3 L min(-1) and an average of 73.4% at flow rates of 60 and 90 L min(-1). In the lung region, the deposition totaled 7.2% at 28.3 L min(-1), 18.3% at 60 L min(-1), and 17.6% at 90 L min(-1). These deposition patterns were consistent with aerodynamic size measurement, which showed 76 to 86% deposition in the USP/EP (US Pharmacopoeia/European Pharmacopoeia) induction port. As the flow rate increased, fewer aggregates were formed resulting in the smaller aerodynamic particles. As a result, more particles penetrated the oral airways and were available for deposition in the lung. Our results showed that L-PLA particles as manufactured by the supercritical technology could be used in a DPI that does not require the use of carrier particles to facilitate aerosol delivery.

Turmeric powder and starch: selected physical, physicochemical, and microstructural properties.

PubMed

Kuttigounder, Dhanalakshmi; Lingamallu, Jaganmohan Rao; Bhattacharya, Suvendu

2011-01-01

Turmeric powder and its starch were characterized for physical, physicochemical, and microstructural characteristics. X-ray diffractogram indicated that turmeric starch to be of B type. Dried and cured-dried turmeric powder samples showed higher water-holding capacity (3.62 and 4.78 g/g, respectively) compared to isolated starch (1.07 g/g) at 30 °C. Non-Newtonian shear-thinning characteristics were observed with turmeric powder dispersion containing 10% (w/w) solids. A power law model fitted well to correlate the shear-rate and shear-stress data (r= 0.993 to 0.999, P≤ 0.01) for both samples. Apparent viscosities of isolated turmeric starch and cured-dried turmeric powder dispersion containing 10% (w/w) solids were 1.29 ± 0.03 and 7.57 ± 0.39 mPa s, respectively. Microstructure of starch particles showed a smooth flat outer surface. The approximate length and breadth of isolated elliptical starches were 25 and 10 μm while the thickness was about 5 μm. Isolation and characterization of starch from an unconventional source like turmeric rhizome indicate a potential application as a functional ingredient in foods and pharmaceutical industries including agglomerated products. © 2011 Institute of Food Technologists®

Valorizing waste iron powder in biogas production: Hydrogen sulfide control and process performances.

PubMed

Andriamanohiarisoamanana, Fetra J; Shirai, Tomoya; Yamashiro, Takaki; Yasui, Seiichi; Iwasaki, Masahiro; Ihara, Ikko; Nishida, Takehiro; Tangtaweewipat, Suchon; Umetsu, Kazutaka

2018-02-15

Biogas is composed of different gases including hydrogen sulfide (H 2 S), which is a hazardous gas that damages pipes and generators in anaerobic digestion system. The objective of this study was to control H 2 S by waste iron powder produced by laser cutting machine in a steel and iron industry. Waste iron powder was mixed with dairy manure at a concentration between 2.0 and 20.0 g/L in batch experiments, while the concentration was varied between 1.0 and 4.0 g/L in bench experiment. In batch experiment, a reduction of up to 93% of H 2 S was observed at waste iron powder of 2.0 g/L (T1), while the reduction was of more than 99% at waste iron powder beyond 8.0 g/L (T4 ∼ T6). The total sulfide concentration (S T ) increased together with waste iron powder concentration and was fitted with a quadratic equation with a maximum S T of 208.0 mg/L at waste iron powder of 20.2 g/L. Waste iron powder did not have significant effect on methane yield in batch and bench experiments. However, hydrolysis rate constant was increased by almost 100%, while the lag-phase period was reduced to half in test digesters compared to that in control digester. In bench experiment, H 2 S concentration was reduced by 89% at 2.0 g/L, while 50% at 1.0 g/L. Therefore, waste iron powder was effectively removed H 2 S and did not affect negatively anaerobic digestion process. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

49 CFR 171.8 - Definitions and abbreviations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... definitions relating to radioactive materials. Rail car means a car designed to carry freight or non-passenger... Materials Safety Administration. Aerosol means any non-refillable receptacle containing a gas compressed... Division 6.1 Packing Group III material) liquid, paste, or powder and fitted with a self-closing release...

49 CFR 171.8 - Definitions and abbreviations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... definitions relating to radioactive materials. Rail car means a car designed to carry freight or non-passenger... Materials Safety Administration. Aerosol means any non-refillable receptacle containing a gas compressed... Division 6.1 Packing Group III material) liquid, paste, or powder and fitted with a self-closing release...

49 CFR 171.8 - Definitions and abbreviations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... definitions relating to radioactive materials. Rail car means a car designed to carry freight or non-passenger... Materials Safety Administration. Aerosol means any non-refillable receptacle containing a gas compressed... Division 6.1 Packing Group III material) liquid, paste, or powder and fitted with a self-closing release...

49 CFR 171.8 - Definitions and abbreviations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... definitions relating to radioactive materials. Rail car means a car designed to carry freight or non-passenger... Materials Safety Administration. Aerosol means any non-refillable receptacle containing a gas compressed... Division 6.1 Packing Group III material) liquid, paste, or powder and fitted with a self-closing release...

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...

Hermetically sealed electrical feedthrough for high temperature secondary cells

DOEpatents

Knoedler, R.; Nelson, P.A.; Shimotake, H.; Battles, J.E.

1983-07-26

A passthrough seal is disclosed for electrically isolating the terminal in a lithium/metal sulfide cell from the structural cell housing. The seal has spaced upper and lower insulator rings fitted snuggly between the terminal and an annularly disposed upstanding wall, and outwardly of a powdered insulator also confined between the upstanding wall and terminal. The adjacent surfaces of the upper insulator ring and the respective upstanding wall and terminal are conically tapered, diverging in the axial direction away from the cell interior, and a sealing ring is located between each pair of the adjacent surfaces. The components are sized so that upon appropriate movement of the upper insulator ring toward the lower insulator ring the powdered insulator and sealing rings are each compressed to a high degree. This compacts the powdered insulator thereby rendering the same highly impervious and moreover fuses the sealing rings to and between the adjacent surfaces. The upper and lower insulator rings might be formed of beryllium oxide and/or alumina, the powdered insulator might be formed of boron nitride, and the sealing rings might be formed of aluminum.

Hermetically sealed electrical feedthrough for high temperature secondary cells

DOEpatents

Knoedler, Reinhard; Nelson, Paul A.; Shimotake, Hiroshi; Battles, James E.

1985-01-01

A passthrough seal is disclosed for electrically isolating the terminal in a lithium/metal sulfide cell from the structural cell housing. The seal has spaced upper and lower insulator rings fitted snuggly between the terminal and an annularly disposed upstanding wall, and outwardly of a powdered insulator also confined between the upstanding wall and terminal. The adjacent surfaces of the upper insulator ring and the respective upstanding wall and terminal are conically tapered, diverging in the axial direction away from the cell interior, and a sealing ring is located between each pair of the adjacent surfaces. The components are sized so that upon appropriate movement of the upper insulator ring toward the lower insulator ring the powdered insulator and sealing rings are each compressed to a high degree. This compacts the powdered insulator thereby rendering the same highly impervious and moreover fuses the sealing rings to and between the adjacent surfaces. The upper and lower insulator rings might be formed of beryllium oxide and/or alumina, the powdered insulator might be formed of boron nitride, and the sealing rings might be formed of aluminum.

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

PubMed

Zunino, Susan J; Keim, Nancy L; Kelley, Darshan S; Bonnel, Ellen L; Souza, Elaine C; Peerson, Janet M

2017-04-01

Recently, in a randomized, double-blind crossover study, we reported that consumption of grape powder by obese human subjects increased the production of the proinflammatory cytokines interleukin (IL)-1β and IL-6 by peripheral blood monocytes after ex vivo stimulation with bacterial lipopolysaccharide compared with the placebo treatment. We hypothesized that dietary grape powder increased the production of these cytokines by stimulated monocytes. To test this hypothesis, we used 24-hour dietary recall data to determine if differences in dietary patterns played a role in increased cytokine production. No differences in total energy, protein, carbohydrates, or fat intake in the diets were observed between the grape powder and placebo intervention periods. There were no differences observed in consumption of meats and poultry, eggs, fish, vegetables, grains, total dairy, or nuts and seeds by the participants between the 2 intervention periods. When participants received the grape powder, the recall data showed decreased intakes of butyric and capric acids (P<.05), and a possible trend toward decreased intake of cheese and total fruit (P<.1). Positive associations between the intakes of margaric acid, butter, total dairy, or whole grain and IL-6 production were observed (P<.05). However, path analysis showed that total energy, protein, carbohydrates, and fats, and individual fatty acids did not influence the production of cytokines by monocytes. The path analysis indicated that the increased cytokine production by lipopolysaccharide-stimulated monocytes from obese human subjects was caused by the grape powder and not mediated by differences in dietary intake. Published by Elsevier Inc.

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...

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 Science and Risk-Based Pragmatic Methodology for Blend and Content Uniformity Assessment.

PubMed

Sayeed-Desta, Naheed; Pazhayattil, Ajay Babu; Collins, Jordan; Doshi, Chetan

2018-04-01

This paper describes a pragmatic approach that can be applied in assessing powder blend and unit dosage uniformity of solid dose products at Process Design, Process Performance Qualification, and Continued/Ongoing Process Verification stages of the Process Validation lifecycle. The statistically based sampling, testing, and assessment plan was developed due to the withdrawal of the FDA draft guidance for industry "Powder Blends and Finished Dosage Units-Stratified In-Process Dosage Unit Sampling and Assessment." This paper compares the proposed Grouped Area Variance Estimate (GAVE) method with an alternate approach outlining the practicality and statistical rationalization using traditional sampling and analytical methods. The approach is designed to fit solid dose processes assuring high statistical confidence in both powder blend uniformity and dosage unit uniformity during all three stages of the lifecycle complying with ASTM standards as recommended by the US FDA.

Deflagration to Detonation Transition (DDT) Simulations of HMX Powder Using the HERMES Model

NASA Astrophysics Data System (ADS)

White, Bradley; Reaugh, John; Tringe, Joseph

2017-06-01

We performed computer simulations of DDT experiments with Class I HMX powder using the HERMES model (High Explosive Response to MEchanical Stimulus) in ALE3D. Parameters for the model were fitted to the limited available mechanical property data of the low-density powder, and to the Shock to Detonation Transition (SDT) test results. The DDT tests were carried out in steel-capped polycarbonate tubes. This arrangement permits direct observation of the event using both flash X-ray radiography and high speed camera imaging, and provides a stringent test of the model. We found the calculated detonation transition to be qualitatively similar to experiment. Through simulation we also explored the effects of confinement strength, the HMX particle size distribution and porosity on the computed detonation transition location. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344.

Study of micropart fabrication via 17-4 PH stainless nanopowder injection molding.

PubMed

Tirta, Andy; Prasetyo, Yus; Baek, Eung-Ryul; Choi, Chul-Jin

2011-01-01

Micropart fabrication via 17-4 PH stainless nanopowder injection molding was investigated. The nanopowder was mixed with a binder that was based on wax to produce a feedstock composed of 45% powder and binder (the powder load). Initially, the fit and proper test was done before the micropart was made by making some bars of green samples, which the properties were examined after the sintering process. The examination involved the mechanical properties such as the porosity, hardness, and some of metallurgical aspects, such as the second-phase formation and the final compound after the sintering. The results showed that utilizing 17-4 PH stainless nanopowder is promising for micropart fabrication since it can form a nearly full-density sintered sample with a low porosity and good toughness, and can provide a smooth surface finish. After this, the investigations followed with the injection of the feedstock into the PDMS micromold that was formed by the nickel pattern from the X-Ray LIGA process. The green samples successfully produced a high-aspect-ratio sample with a thickness of up to 1 mm and an aspect ratio of 15 in the microchannel part. Then the green samples were sintered at 1,300 degrees C for 2 h, since from the initial test, they showed optimum parameters with nearly full density, low porosity, and a high degree of hardness. The research shows the excellent results of the application of the 17-4 PH stainless nanopowder to micropart fabrication.

Revisiting the magnetic structure and charge ordering in La1 /3Sr2 /3FeO3 by neutron powder diffraction and Mössbauer spectroscopy

NASA Astrophysics Data System (ADS)

Li, F.; Pomjakushin, V.; Mazet, T.; Sibille, R.; Malaman, B.; Yadav, R.; Keller, L.; Medarde, M.; Conder, K.; Pomjakushina, E.

2018-05-01

The magnetic ordering of La1 /3Sr2 /3FeO3 perovskite has been studied by neutron powder diffraction and 57Fe Mössbauer spectroscopy down to 2 K. From symmetry analysis, a chiral helical model and a collinear model are proposed to describe the magnetic structure. Both are commensurate, with propagation vector k =(0 ,0 ,1 ) in R 3 ¯c space group. In the former model, the magnetic moments of Fe adopt the magnetic space group P 3221 and have helical and antiferromagnetic ordering propagating along the c axis. The model allows only a single Fe site, with a magnetic moment of 3.46(2)μB at 2 K. In the latter model, the magnetic moments of iron ions adopt the magnetic space group C 2 /c or C 2'/c' and are aligned collinearly. The model allows the presence of two inequivalent Fe sites with magnetic moments of amplitude 3.26(3)μB and 3.67(2)μB, respectively. The neutron-diffraction pattern is equally well fitted by either model. The Mössbauer spectroscopy study suggests a single charge state Fe3.66 + above the magnetic transition and a charge disproportionation into Fe(3.66 -ζ )+ and Fe(3.66 +2 ζ )+ below the magnetic transition. The compatibility of the magnetic structure models with the Mössbauer spectroscopy results is discussed.

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.

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

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.

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.

Compressibility of binary powder formulations: investigation and evaluation with compaction equations.

PubMed

Gentis, Nicolaos D; Betz, Gabriele

2012-02-01

The purpose of this work was to investigate and evaluate the powder compressibility of binary mixtures containing a well-compressible compound (microcrystalline cellulose) and a brittle active drug (paracetamol and mefenamic acid) and its progression after a drug load increase. Drug concentration range was 0%-100% (m/m) with 10% intervals. The powder formulations were compacted to several relative densities with the Zwick material tester. The compaction force and tensile strength were fitted to several mathematical models that give representative factors for the powder compressibility. The factors k and C (Heckel and modified Heckel equation) showed mostly a nonlinear correlation with increasing drug load. The biggest drop in both factors occurred at far regions and drug load ranges. This outcome is crucial because in binary mixtures the drug load regions with higher changeover of plotted factors could be a hint for an existing percolation threshold. The susceptibility value (Leuenberger equation) showed varying values for each formulation without the expected trend of decrease for higher drug loads. The outcomes of this study showed the main challenges for good formulation design. Thus, we conclude that such mathematical plots are mandatory for a scientific evaluation and prediction of the powder compaction process. Copyright © 2011 Wiley Periodicals, Inc.

Soft computing modelling of moisture sorption isotherms of milk-foxtail millet powder and determination of thermodynamic properties.

PubMed

Simha, H V Vikram; Pushpadass, Heartwin A; Franklin, Magdaline Eljeeva Emerald; Kumar, P Arun; Manimala, K

2016-06-01

Moisture sorption isotherms of spray-dried milk-foxtail millet powder were determined at 10, 25 and 40 °C. Sorption data was fitted using classical and soft-computing approaches. The isotherms were of type II, and equilibrium moisture content (EMC) was temperature dependent. The BET monolayer moisture content decreased from 3.30 to 2.67 % as temperature increased from 10 to 40 °C. Amongst the classical models, Ferro-Fontan gave the best fit of EMC-aw data. However, the Sugeno-type adaptive neuro-fuzzy inference system (ANFIS) with generalized bell-shaped membership function performed better than artificial neural network and classical models with RMSE as low as 0.0099. The isosteric heat of sorption decreased from 150.32 kJ mol(-1) at 1 % moisture content to 44.11 kJ mol(-1) at 15 % moisture. The enthalpy-entropy compensation theory was validated, and the isokinetic and harmonic mean temperatures were determined as 333.1 and 297.5 K, respectively.

Biosorption of Cu(II) by powdered anaerobic granular sludge from aqueous medium.

PubMed

Zhou, Xu; Chen, Chuan; Wang, Aijie; Jiang, Guangming; Liu, Lihong; Xu, Xijun; Yuan, Ye; Lee, Duu-Jung; Ren, Nanqi

2013-01-01

Copper(II) biosorption processes by two pre-treated powdered anaerobic granular sludges (PAGS) (original sludges were methanogenic anaerobic granules and denitrifying sulfide removal (DSR) anaerobic granules) were investigated through batch tests. Factors affecting the biosorption process, such as pH, temperature and initial copper concentrations, were examined. Also, the physico-chemical characteristics of the anaerobic sludge were analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy image, surface area and elemental analysis. A second-order kinetic model was applied to describe the biosorption process, and the model could fit the biosorption process. The Freundlich model was used for describing the adsorption equilibrium data and could fit the equilibrium data well. It was found that the methanogenic PAGS was more effective in Copper(II) biosorption process than the DSR PAGS, whose maximum biosorption capacity was 39.6% lower. The mechanisms of the biosorption capacities for different PAGS were discussed, and the conclusion suggested that the environment and biochemical reactions during the growth of biomass may have affected the structure of the PAGS. The methanogenic PAGS had larger specific surface area and more biosorption capacity than the DSR PAGS.

Determination of sendust intrinsic permeability from microwave constitutive parameters of composites with sendust spheres and flakes

NASA Astrophysics Data System (ADS)

Starostenko, Sergey N.; Rozanov, Konstantin N.; Shiryaev, Artem O.; Shalygin, Alexander N.; Lagarkov, Andrey N.

2017-06-01

Intrinsic permeability of sendust alloys is determined from the measured microwave permittivity and permeability of composites filled with either spherical or flaky sendust powders. The permittivity and permeability measurements are performed applying the coaxial reflection-transmission technique in the 0.05 to 18 GHz frequency range. The effects of the filling factor, inclusion shape, and size on composite constitutive parameters are discussed. The permeability of metal inclusion is retrieved from the measured permeability of composites using a generalized Maxwell Garnett equation that accounts for the percolation threshold. The equation parameters are found by fitting the measured dependence of composite permittivity and permeability on frequency and filling. The inclusion dimensions calculated from the found parameters agree with the results of grain-size analyses. The alloy intrinsic permeability is retrieved from inclusion permeability with the account for skinning. The fitted frequency and damping factor of ferromagnetic resonance depend on the inclusion shape. The calculated reflectivity map of the flake-filled composite shows that sendust powders are promising fillers for interference suppressors and microwave absorbers at frequencies close to 1 GHz.

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.

Fitness Profiles and Activity Patterns of Entering College Students.

ERIC Educational Resources Information Center

Pierce, Edgar F.; And Others

1992-01-01

Entering college students were evaluated for performance on maximal oxygen consumption, body composition, muscle endurance, muscle strength, and joint flexibility tests to determine the relationship of physical activity patterns to fitness levels. Results supported previous research indicating reduced fitness levels in young adults. (SM)

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.

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.

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.

[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.

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.

A Practical Guide to Check the Consistency of Item Response Patterns in Clinical Research Through Person-Fit Statistics: Examples and a Computer Program.

PubMed

Meijer, Rob R; Niessen, A Susan M; Tendeiro, Jorge N

2016-02-01

Although there are many studies devoted to person-fit statistics to detect inconsistent item score patterns, most studies are difficult to understand for nonspecialists. The aim of this tutorial is to explain the principles of these statistics for researchers and clinicians who are interested in applying these statistics. In particular, we first explain how invalid test scores can be detected using person-fit statistics; second, we provide the reader practical examples of existing studies that used person-fit statistics to detect and to interpret inconsistent item score patterns; and third, we discuss a new R-package that can be used to identify and interpret inconsistent score patterns. © The Author(s) 2015.

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™.

Predicting the shock compression response of heterogeneous powder mixtures

NASA Astrophysics Data System (ADS)

Fredenburg, D. A.; Thadhani, N. N.

2013-06-01

A model framework for predicting the dynamic shock-compression response of heterogeneous powder mixtures using readily obtained measurements from quasi-static tests is presented. Low-strain-rate compression data are first analyzed to determine the region of the bulk response over which particle rearrangement does not contribute to compaction. This region is then fit to determine the densification modulus of the mixture, σD, an newly defined parameter describing the resistance of the mixture to yielding. The measured densification modulus, reflective of the diverse yielding phenomena that occur at the meso-scale, is implemented into a rate-independent formulation of the P-α model, which is combined with an isobaric equation of state to predict the low and high stress dynamic compression response of heterogeneous powder mixtures. The framework is applied to two metal + metal-oxide (thermite) powder mixtures, and good agreement between the model and experiment is obtained for all mixtures at stresses near and above those required to reach full density. At lower stresses, rate-dependencies of the constituents, and specifically those of the matrix constituent, determine the ability of the model to predict the measured response in the incomplete compaction regime.

Antioxidative effect of Assam Tea (Camellia sinesis Var. Assamica) extract on rice bran oil and its application in breakfast cereal.

PubMed

Utama-Ang, Niramon; Phawatwiangnak, Kamonyanun; Naruenartwongsakul, Srisuwan; Samakradhamrongthai, Rajnibhas

2017-04-15

The objectives of this research were to investigate the antioxidant effect of Assam tea extract (ATE) and whether it is fit to utilise ATE by fortification in rice bran breakfast cereal (RBC). The increasing ATE powder from 0.1 to 0.3mg/g affected to be decreased. The ATE powder at 0.3mg/g was proved to have decreased the hexanal content (0.21μg/ml) and thiobarbituric acid reactive substances (TBARS) (2.56μg/g) within 28days, and provided the highest antioxidant ability (EC50) (2481.44mg/kg). The fortified 0.3mg/g of ATE powder showed that increasing ATE significantly increased the total phenolic content and decreased TBARS and EC50 of breakfast cereal (p<0.05). The suitable amount ATE powder added in RBC was 0.5%. The consumer acceptance (n=200) of final product showed the sensory scores in the range of 6.3-6.8, with the percentages of acceptance and purchase intention at 98.0% and 89.0%, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

SPS Fabrication of Tungsten-Rhenium Alloys in Support of NTR Fuels Development

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

Jonathan A. Webb; Indrajit Charit; Cory Sparks

Abstract. Tungsten metal slugs were fabricated via Spark Plasma Sintering (SPS) of powdered metals at temperatures ranging from 1575 K to 1975 K and hold times of 5 minutes to 30 minutes, using powders with an average diameter of 7.8 ?m. Sintered tungsten specimens were found to have relative densities ranging from 83 % to 94 % of the theoretical density for tungsten. Consolidated specimens were also tested for their Vickers Hardness Number (VHN), which was fitted as a function of relative density; the fully consolidated VHN was extrapolated to be 381.45 kg/mm2. Concurrently, tungsten and rhenium powders with averagemore » respective diameters of 0.5 ?m and 13.3 ?m were pre-processed either by High-Energy-Ball-Milling (HEBM) or by homogeneous mixing to yield W-25at.%Re mixtures. The powder batches were sintered at temperatures of 1975 K and 2175 K for hold times ranging from 0 minutes to 60 minutes yielding relative densities ranging from 94% to 97%. The combination of HEBM and sintering showed a significant decrease in the inter-metallic phases compared to that of the homogenous mixing and sintering.« less

Reduction experiment of iron scale by adding waste plastics.

PubMed

Zhang, Chongmin; Chen, Shuwen; Miao, Xincheng; Yuan, Hao

2009-01-01

The special features of waste plastics in China are huge in total amount, various in type and dispersive in deposition. Therefore, it is necessary to try some new ways that are fit to Chinese situation for disposing waste plastics as metallurgical raw materials more effectively and flexibly. Owing to its high ferrous content and less impurity, the iron scale became ideal raw material to produce pure iron powder. One of the methods to produce pure iron powder is Hoganas Method, by which, after one or multistage of reduction steps, the iron scale can be reduced pure iron powder. However, combining utilization of waste plastics and iron powder production, a series of reduction experiments were arranged and investigated, which is hoped to take use of both thermal and chemical energy contained in waste plastics as well as to improve the reducing condition of iron scale, and hence to develop a new metallurgical way of disposing waste plastics. The results show that under these experimental conditions, the thermal-decomposition of water plastics can conduce to an increase of porosity in the reduction systems. Moreover, better thermodynamics and kinetics conditions for the reduction of scale can be reached. As a result, the reduction rate is increased.

LONGITUDINAL PATTERNS OF CARDIORESPIRATORY FITNESS PREDICT THE DEVELOPMENT OF HYPERTENSION AMONG MEN AND WOMEN

PubMed Central

Sui, Xuemei; Sarzynski, Mark A.; Lee, Duck-chul; Lavie, Carl J.; Zhang, Jiajia; Kokkinos, Peter F.; Payne, Jonathan; Blair, Steven N.

2016-01-01

Background Most of the existing literature has linked either a baseline cardiorespiratory fitness, or change between baseline and one follow-up measurement of cardiorespiratory fitness, to hypertension. The purpose of the study is to assess the association between longitudinal patterns of cardiorespiratory fitness changes with time and incident hypertension in adult men and women. Patients and Methods Participants were aged from 20 to 82 years, free of hypertension during the first three examinations, and received at least four preventive medical examinations at the Cooper Clinic in Dallas, TX, during 1971 – 2006. They were classified into one of five groups based on all of the measured cardiorespiratory fitness values (in metabolic equivalents) during maximal treadmill tests. Logistic regression was used to compute odds ratios and 95% confidence intervals. Results Among a total of 4,932 participants (13% women), 1,954 developed hypertension. After controlling for baseline potential confounders, follow-up duration, and number of follow-up visits, odds ratios (95% confidence intervals) for hypertension were: 1.00 for decreasing group (referent), 0.64 (0.52–0.80) for increasing, 0.89 (0.70–1.12) for Bell-shape, 0.78 (0.62–0.98) for U-shape, and 0.83 (0.69–1.00) for inconsistent group. The general pattern of the association was consistent regardless of participants’ baseline cardiorespiratory fitness or body mass index levels. Conclusion An increasing pattern of cardiorespiratory fitness provides the lowest risk of hypertension in this middle-aged relatively healthy population. Identifying specific pattern(s) of cardiorespiratory fitness change may be important for determining associations with comorbidity such as hypertension. PMID:27986522

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.

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.

[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.

Visualisation of Lines of Best Fit

ERIC Educational Resources Information Center

Rudziewicz, Michael; Bossé, Michael J.; Marland, Eric S.; Rhoads, Gregory S.

2017-01-01

Humans possess a remarkable ability to recognise both simple patterns such as shapes and handwriting and very complex patterns such as faces and landscapes. To investigate one small aspect of human pattern recognition, in this study participants position lines of "best fit" to two-dimensional scatter plots of data. The study investigates…

Sedentary patterns, physical activity and health-related physical fitness in youth: a cross-sectional study.

PubMed

Júdice, Pedro B; Silva, Analiza M; Berria, Juliane; Petroski, Edio L; Ekelund, Ulf; Sardinha, Luís B

2017-03-04

Strong evidence indicates that moderate-vigorous physical activity (MVPA) is positively associated with fitness in youth, independent of total sedentary-time. Sedentary-time appears negatively associated with fitness only when it replaces MVPA. However, whether different sedentary-patterns affect health-related fitness is unknown. The associations between MVPA and sedentary-patterns with physical fitness were examined in 2698 youths (1262 boys) aged 13.4 ± 2.28 years. Sedentary-time (counts · minute -1  < 100) and PA were objectively measured by accelerometry. Each break (≥100 counts · min -1  < 2295) in sedentary-time and the frequency of daily bouts in non-prolonged (<30 min) and prolonged (≥30 min) sedentary-time were determined. The FITNESSGRAM® test battery was used to assess fitness. A standardized fitness composite-score (z-score) was calculated by summing the individual z-scores of the five tests adjusted to age and sex. Positive associations between MVPA and fitness were observed in both boys (β = 0.013, 95% CI: 0.005; 0.021) and girls (β = 0.014, 95% CI: 0.006; 0.022), independent of sedentary-patterns. Modest associations were found for the breaks in sedentary-time with fitness (β = 0.026, 95% CI: 0.009; 0.042), independent of total sedentary-time and MVPA in boys. In girls, non-prolonged sedentary bouts were positively associated with fitness (β = 0.014, 95% CI: 0.003; 0.024), independent of total sedentary-time and MVPA. These results reinforce that, independent of the time and patterns of sedentary behavior, MVPA is consistently associated with fitness in youth. Modest and inconsistent associations were found for sedentary behaviors. Breaking-up sedentary-time in boys and non-prolonged sedentary bouts in girls were positively associated with fitness, independent of total sedentary-time and MVPA. In order to enhance youth's fitness, public health recommendations should primarily target MVPA, still, suggestion to reduce and break-up sedentary-time may also be considered.

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

Authentication of Whey Protein Powders by Portable Mid-Infrared Spectrometers Combined with Pattern Recognition Analysis.

PubMed

Wang, Ting; Tan, Siow Ying; Mutilangi, William; Aykas, Didem P; Rodriguez-Saona, Luis E

2015-10-01

The objective of this study was to develop a simple and rapid method to differentiate whey protein types (WPC, WPI, and WPH) used for beverage manufacturing by combining the spectral signature collected from portable mid-infrared spectrometers and pattern recognition analysis. Whey protein powders from different suppliers are produced using a large number of processing and compositional variables, resulting in variation in composition, concentration, protein structure, and thus functionality. Whey protein powders including whey protein isolates, whey protein concentrates and whey protein hydrolysates were obtained from different suppliers and their spectra collected using portable mid-infrared spectrometers (single and triple reflection) by pressing the powder onto an Attenuated Total Reflectance (ATR) diamond crystal with a pressure clamp. Spectra were analyzed by soft independent modeling of class analogy (SIMCA) generating a classification model showing the ability to differentiate whey protein types by forming tight clusters with interclass distance values of >3, considered to be significantly different from each other. The major bands centered at 1640 and 1580 cm(-1) were responsible for separation and were associated with differences in amide I and amide II vibrations of proteins, respectively. Another important band in whey protein clustering was associated with carboxylate vibrations of acidic amino acids (∼1570 cm(-1)). The use of a portable mid-IR spectrometer combined with pattern recognition analysis showed potential for discriminating whey protein ingredients that can help to streamline the analytical procedure so that it is more applicable for field-based screening of ingredients. A rapid, simple and accurate method was developed to authenticate commercial whey protein products by using portable mid-infrared spectrometers combined with chemometrics, which could help ensure the functionality of whey protein ingredients in food applications. © 2015 Institute of Food Technologists®

Resistance of virus to extinction on bottleneck passages: study of a decaying and fluctuating pattern of fitness loss

NASA Technical Reports Server (NTRS)

Lazaro, Ester; Escarmis, Cristina; Perez-Mercader, Juan; Manrubia, Susanna C.; Domingo, Esteban

2003-01-01

RNA viruses display high mutation rates and their populations replicate as dynamic and complex mutant distributions, termed viral quasispecies. Repeated genetic bottlenecks, which experimentally are carried out through serial plaque-to-plaque transfers of the virus, lead to fitness decrease (measured here as diminished capacity to produce infectious progeny). Here we report an analysis of fitness evolution of several low fitness foot-and-mouth disease virus clones subjected to 50 plaque-to-plaque transfers. Unexpectedly, fitness decrease, rather than being continuous and monotonic, displayed a fluctuating pattern, which was influenced by both the virus and the state of the host cell as shown by effects of recent cell passage history. The amplitude of the fluctuations increased as fitness decreased, resulting in a remarkable resistance of virus to extinction. Whereas the frequency distribution of fitness in control (independent) experiments follows a log-normal distribution, the probability of fitness values in the evolving bottlenecked populations fitted a Weibull distribution. We suggest that multiple functions of viral genomic RNA and its encoded proteins, subjected to high mutational pressure, interact with cellular components to produce this nontrivial, fluctuating pattern.

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

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

Ultrasonic sensing of powder densification

NASA Technical Reports Server (NTRS)

Lu, Yichi; Wadley, Haydn N. G.; Parthasarathi, Sanjai

1992-01-01

An independent scattering theory has been applied to the interpretation of ultrasonic velocity measurements made on porous metal samples produced either by a cold or a high-temperature compaction process. The results suggest that the pores in both processes are not spherical, an aspect ration of 1:3 fitting best with the data for low (less than 4 percent) pore volume fractions. For the hot compacted powders, the pores are smooth due to active diffusional processes during processing. For these types of voids, the results can be extended to a pore fraction of 10 percent, at which point voids form an interconnected network that violates the model assumptions. The cold pressed samples are not as well predicted by the theory because of poor particle bonding.

Method for Detecting Perlite Compaction in Large Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Youngquist, Robert

2010-01-01

Perlite is the most typical insulating powder used to separate the inner and outer shells of cryogenic tanks. The inner tank holds the low-temperature commodity, while the outer shell is exposed to the ambient temperature. Perlite minimizes radiative energy transfer between the two tanks. Being a powder, perlite will settle over time, leading to the danger of transferring any loads from the inner shell to the outer shell. This can cause deformation of the outer shell, leading to damaged internal fittings. The method proposed is to place strain or displacement sensors on several locations of the outer shell. Loads induced on the shell by the expanding inner shell and perlite would be monitored, providing an indication of the location and degree of compaction.

New approach to the calculation of pistachio powder hysteresis

NASA Astrophysics Data System (ADS)

Tavakolipour, Hamid; Mokhtarian, Mohsen

2016-04-01

Moisture sorption isotherms for pistachio powder were determined by gravimetric method at temperatures of 15, 25, 35 and 40°C. A selected mathematical models were tested to determine the best suitable model to predict isotherm curve. The results show that Caurie model had the most satisfactory goodness of fit. Also, another purpose of this research was to introduce a new methodology to determine the amount of hysteresis at different temperatures by using best predictive model of isotherm curve based on definite integration method. The results demonstrated that maximum hysteresis is related to the multi-layer water (in the range of water activity 0.2-0.6) which corresponds to the capillary condensation region and this phenomenon decreases with increasing temperature.

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.

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.

76 FR 68219 - Notice of Determinations Regarding Eligibility To Apply for Worker Adjustment Assistance and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-03

... received a certification of eligibility to apply for trade adjustment assistance benefits and such supply... Fit Industries, LLC, Monroe, NC: August 9, 2010, TA-W-80,472; Tiger Drylac USA, Inc., Reading, PA: September 26, 2010, TA-W-80,473; Reading Powder Coatings, Inc., Reading, PA: September 26, 2010, TA-W-80,484...

Geometry modeling of single track cladding deposited by high power diode laser with rectangular beam spot

NASA Astrophysics Data System (ADS)

Liu, Huaming; Qin, Xunpeng; Huang, Song; Hu, Zeqi; Ni, Mao

2018-01-01

This paper presents an investigation on the relationship between the process parameters and geometrical characteristics of the sectional profile for the single track cladding (STC) deposited by High Power Diode Laser (HPDL) with rectangle beam spot (RBS). To obtain the geometry parameters, namely cladding width Wc and height Hc of the sectional profile, a full factorial design (FFD) of experiment was used to conduct the experiments with a total of 27. The pre-placed powder technique has been employed during laser cladding. The influence of the process parameters including laser power, powder thickness and scanning speed on the Wc and Hc was analyzed in detail. A nonlinear fitting model was used to fit the relationship between the process parameters and geometry parameters. And a circular arc was adopted to describe the geometry profile of the cross-section of STC. The above models were confirmed by all the experiments. The results indicated that the geometrical characteristics of the sectional profile of STC can be described as the circular arc, and the other geometry parameters of the sectional profile can be calculated only using Wc and Hc. Meanwhile, the Wc and Hc can be predicted through the process parameters.

Evolution of structure and magnetic properties for BaFe11.9Al0.1O19 hexaferrite in a wide temperature range

NASA Astrophysics Data System (ADS)

Trukhanov, A. V.; Trukhanov, S. V.; Panina, L. V.; Kostishyn, V. G.; Kazakevich, I. S.; Trukhanov, An. V.; Trukhanova, E. L.; Natarov, V. O.; Turchenko, V. A.; Salem, M. M.; Balagurov, A. M.

2017-03-01

M-type BaFe11.9Al0.1O19 hexaferrite was successfully synthesized by solid state reactions. Precision investigations of crystal and magnetic structures of BaFe11.9Al0.1O19 powder by neutron diffraction in the temperature range 4.2-730 K have been performed. Magnetic and electrical properties investigations were carried out in the wide temperature range. Neutron powder diffraction data were successfully refined in approximation for both space groups (SG): centrosymmetric #194 (standard non-polar phase) and non-centrosymmetric #186 (polar phase). It has been shown that at low temperatures (below room temperature) better fitting results (value χ2) were for the polar phase (SG: #186) or for the two phases coexistence (SG: #186 and SG: #194). At high temperatures (400-730 K) better fitting results were for SG: #194. It was established coexistence of the dual ferroic properties (specific magnetization and spontaneous polarization) at room temperature. Strong correlation between magnetic and electrical subsystems was demonstrated (magnetoelectrical effect). Temperature dependences of the spontaneous polarization, specific magnetization and magnetoelectrical effect were investigated.

Scanning Electron Microscopy (SEM) Procedure for HE Powders on a Zeiss Sigma HD VP SEM

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

Zaka, F.

This method describes the characterization of inert and HE materials by the Zeiss Sigma HD VP field emission Scanning Electron Microscope (SEM). The SEM uses an accelerated electron beam to generate high-magnification images of explosives and other materials. It is fitted with five detectors (SE, Inlens, STEM, VPSE, HDBSD) to enable imaging of the sample via different secondary electron signatures, angles, and energies. In addition to imaging through electron detection, the microscope is also fitted with two Oxford Instrument Energy Dispersive Spectrometer (EDS) 80 mm detectors to generate elemental constituent spectra and two-dimensional maps of the material being scanned.

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.

Additional evidence from x-ray powder diffraction patterns that icosahedral quasi-crystals of intermetallic compounds are twinned cubic crystals

PubMed Central

Pauling, Linus

1988-01-01

Analysis of the measured values of Q for the weak peaks (small maxima, usually considered to be background fluctuations, “noise”) on the x-ray powder diffraction curves for 17 rapidly quenched alloys leads directly to the conclusion that they are formed by an 820-atom or 1012-atom primitive cubic structure that by icosahedral twinning produces the so-called icosahedral quasi-crystals. PMID:16593948

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.

Fabrication and evaluation of nanoparticle-assembled BSA microparticles for enhanced liver delivery of glycyrrhetinic acid.

PubMed

Wang, Wenping; Lei, Yaya; Sui, Hong; Zhang, Wenping; Zhu, Rongyue; Feng, Jun; Wang, Hong

2017-06-01

The aim of the present study was to prepare and evaluate microparticle formulation encapsulated with glycyrrhetinic acid (GA) based on bovine serum albumin (BSA). The drug-loaded nanoparticles were firstly formed by a simple desolvation method, and were further assembled into microparticles using zinc chloride and glutaraldehyde as crosslinkers. The obtained microparticles contained approximately 30% (w/w) drug and showed as spherical particles with a size of about 2 μm. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) analysis indicated that GA lost its crystallinity during the nano/microencapsulation process. In vitro dissolution study demonstrated a typical sustained-release pattern for 24 h with a burst of 28.1% at the first 30 min, which fitted well by Higuchi model. After intravenous administration into mice, the microparticle formulation remained a higher drug level than the solution formulation in blood and liver for more than 18 h. These results suggested the potential benefit of using the prepared albumin microparticles as a promising vector for enhanced liver delivery of poorly water-soluble drug.

Influence of Ce Doping on Structural and Transport Properties of Ca1- x Ce x MnO3 ( x=0.2) Manganite

NASA Astrophysics Data System (ADS)

Varshney, Dinesh; Mansuri, Irfan

2011-01-01

We have investigated structural, electric, magnetic and thermal transport properties of electron doped Ca1- x Ce x MnO3 ( x=0.2) manganites. The Cerium substitution for Ca2+causes electron doping into insulating CaMnO3 without e g electron. At room temperature the polycrystalline Ca0.8Ce0.2MnO3 is in the crystallographic orthorhombic structure, with Pnma space group symmetry from the refinement of x-ray powder diffraction patterns. The electrical resistivity data infers that Ca0.8Ce0.2MnO3 manganite is in the semiconducting phase. A smooth linear behavior of log plot values is obtained and is well fitted with adiabatic small polaron conduction model. Nearest-neighbor hopping of a small polaron leads to a mobility with a thermally activated form. The negative values of thermopower infer electron as carriers in Ca0.8Ce0.2MnO3. From susceptibility measurements the Ce doped CaMnO3 shows a transition from antiferromagnetic (AFM) to paramagnetic (PM) phase.

The l z ( p ) * Person-Fit Statistic in an Unfolding Model Context.

PubMed

Tendeiro, Jorge N

2017-01-01

Although person-fit analysis has a long-standing tradition within item response theory, it has been applied in combination with dominance response models almost exclusively. In this article, a popular log likelihood-based parametric person-fit statistic under the framework of the generalized graded unfolding model is used. Results from a simulation study indicate that the person-fit statistic performed relatively well in detecting midpoint response style patterns and not so well in detecting extreme response style patterns.

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.

Spectral optical coherence tomography vs. fluorescein pattern for rigid gas-permeable lens fit.

PubMed

Piotrowiak, Ilona; Kaluzny, Bartłomiej Jan; Danek, Beata; Chwiędacz, Adam; Sikorski, Bartosz Lukasz; Malukiewicz, Grażyna

2014-07-04

This study aimed to evaluate anterior segment spectral optical coherence tomography (AS SOCT) for assessing the lens-to-cornea fit of rigid gas-permeable (RGP) lenses. The results were verified with the fluorescein pattern method, considered the criterion standard for RGP lens alignment evaluations. Twenty-six eyes of 14 patients were enrolled in the study. Initial base curve radius (BCR) of each RGP lens was determined on the basis of keratometry readings. The fluorescein pattern and AS SOCT tomograms were evaluated, starting with an alignment fit, and subsequently, with BCR reductions in increments of 0.1 mm, up to 3 consecutive changes. AS SOCT examination was performed with the use of RTVue (Optovue, California, USA). The average BCR for alignment fits, defined according to the fluorescein pattern, was 7.8 mm (SD=0.26). Repeatability of the measurements was 18.2%. BCR reductions of 0.1, 0.2, and 0.3 mm resulted in average apical clearances detected with AS SOCT of 12.38 (SD=9.91, p<0.05), 28.79 (SD=15.39, p<0.05), and 33.25 (SD=10.60, p>0.05), respectively. BCR steepening of 0.1 mm or more led to measurable changes in lens-to-cornea fits. Although AS SOCT represents a new method of assessing lens-to-cornea fit, apical clearance detection with current commercial technology showed lower sensitivity than the fluorescein pattern assessment.

Cardiorespiratory fitness is positively associated with a healthy dietary pattern in New Zealand adolescents.

PubMed

Howe, Anna S; Skidmore, Paula M L; Parnell, Winsome R; Wong, Jyh Eiin; Lubransky, Alexandra C; Black, Katherine E

2016-05-01

To examine the association between cardiorespiratory fitness and dietary patterns in adolescents. Food choice was assessed using the validated New Zealand Adolescent FFQ. Principal components analysis was used to determine dietary patterns. Trained research assistants measured participants' height and body mass. Cardiorespiratory fitness was assessed in a subset of participants using the multistage 20 m shuttle run. The level and stage were recorded, and the corresponding VO2max was calculated. Differences in mean VO2max according to sex and BMI were assessed using t tests, while associations between cardiorespiratory fitness and dietary patterns were examined using linear regression analyses adjusted for age, sex, school attended, socio-economic deprivation and BMI. Secondary schools in Otago, New Zealand. Students (n 279) aged 14-18 years who completed an online lifestyle survey during a class period. Principal components analysis produced three dietary patterns: 'Treat Foods', 'Fruits and Vegetables' and 'Basic Foods'. The 279 participants who provided questionnaire data and completed cardiorespiratory fitness testing had a mean age of 15·7 (sd 0·9) years. Mean VO2max was 45·8 (sd 6·9) ml/kg per min. The 'Fruits and Vegetables' pattern was positively associated with VO2max in the total sample (β=0·04; 95%CI 0·02, 0·07), girls (β=0·06; 95% CI 0·03, 0·10) and boys (β=0·03; 95% CI 0·01, 0·05). These results indicate that increase in cardiorespiratory fitness was associated with a healthier dietary pattern, suggesting both should be targeted as part of a global lifestyle approach. Longitudinal studies are needed to confirm this association in relation to health outcomes in New Zealand adolescents.

Discerning Viable from Nonviable Yersinia pestis pgm- and Bacillus anthracis Sterne using Propidium Monoazide in the Presence of White Powders

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

Hess, Becky M.; Kaiser, Brooke LD; Sydor, Michael A.

ABSTRACT Aims To develop and optimize an assay to determine viability status of Bacillus anthracis Sterne and Yersinia pestis pgm- strains in the presence of white powders by coupling propidium monoazide (PMA) treatment with real-time PCR (qPCR) analysis. Methods and Results PMA selectively enters nonviable cells and binds DNA, thereby increasing qPCR assay cycle threshold (CT) values compared to untreated samples. Dye concentration, cell number and fitness, incubation time, inactivation methods, and assay buffer were optimized for B. anthracis Sterne and Y. pestis pgm-. Differences in CT values in nonviable cells compared to untreated samples were consistently > 9 formore » both B. anthracis Sterne vegetative cells and Y. pestis pgm- in the presence and absence of three different white powders. Our method eliminates the need for a DNA extraction step prior to detection by qPCR. Conclusions The developed assay enables simultaneous identification and viability assessment for B. anthracis Sterne and Y. pestis pgm- under laboratory conditions, even in the presence of white powders. Eliminating the DNA extraction step that is typically used reduces total assay time and labor requirements for sample analysis. Significance and Impact of the Study The method developed for simultaneous detection and viability assessment for B. anthracis and Y. pestis can be employed in forming decisions about the severity of a biothreat event or the safety of food. Keywords Bacillus anthracis, Yersinia pestis, Propidium Monoazide, qPCR, White Powders, Rapid Viability Detection« less

Optimisation of spray drying process conditions for sugar nanoporous microparticles (NPMPs) intended for inhalation.

PubMed

Amaro, Maria Inês; Tajber, Lidia; Corrigan, Owen I; Healy, Anne Marie

2011-12-12

The present study investigated the effect of operating parameters of a laboratory spray dryer on powder characteristics, in order to optimise the production of trehalose and raffinose powders, intended to be used as carriers of biomolecules for inhalation. The sugars were spray dried from 80:20 methanol:n-butyl acetate (v/v) solutions using a Büchi Mini Spray dryer B-290. A 2(4) factorial design of experiment (DOE) was undertaken. Process parameters studied were inlet temperature, gas flow rate, feed solution flow rate (pump setting) and feed concentration. Resulting powders where characterised in terms of yield, particle size (PS), residual solvent content (RSC) and outlet temperature. An additional outcome evaluated was the specific surface area (SSA) (by BET gas adsorption), and a relation between SSA and the in vitro deposition of the sugar NPMPs powders was also investigated. The DOE resulted in well fitted models. The most significant factors affecting the characteristics of the NPMPs prepared, at a 95% confidence interval, were gas flow: yield, PS and SSA; pump setting: yield; inlet temperature: RSC. Raffinose NPMPs presented better characteristics than trehalose NPMPs in terms of their use for inhalation, since particles with larger surface area resulting in higher fine particle fraction can be produced. Copyright © 2011 Elsevier B.V. All rights reserved.

Anomalous Oxidative Diffusion in Titanium Pyrotechnic Powders

DOE PAGES

Erikson, William W.; Coker, Eric N.

2016-11-10

It has long been observed that oxidation processes in metals tend to follow a parabolic rate law associated with the growth of a surface oxide layer. Here we observe that for certain titanium powders, the expected parabolic law (∝t 1/2) is recovered, yet for others, the exponent differs significantly. One explanation for this non-parabolic, anomalous diffusion arises from fractal geometry. Theoretical considerations indicate that the time response of diffusion-limited processes in an object closely follow a power-law in time (t n) with n=(E–D)/2, where E is the object's Euclidean dimension and D is its boundary's Hausdorff dimension. Non-integer, (fractal) valuesmore » of D will result in n≠1/2. Finite element simulations of several canonical fractal objects were performed to verify the application of this theory; the results matched the theory well. Two different types of titanium powder were tested in isothermal thermogravimetric tests under dilute oxygen. Time-dependent mass uptake data were fit with power-law forms and the associated exponents were used to determine an equivalent fractal dimension. One Ti powder type has an implied surface dimension of ca. 2.3 to 2.5, suggesting fractal geometry may be operative. Finally, the other has a dimension near 2.0, indicating it behaves like traditional material.« less

Driving Ability of HMX based Aluminized Explosive Affected by the Reaction Degree of Aluminum Powder

NASA Astrophysics Data System (ADS)

Duan, Yingliang

2017-06-01

Due to the time scale of aluminum reaction, the detonation process of the aluminized explosive becomes very complex, and there is less agreement on the reaction mechanism of aluminum powder. If the reaction of aluminum occurs in the reaction zone, the energy released will further strengthen the work ability of detonation wave. So it is very important for characterizing the detonation parameters and detonation driving ability to accurately understand the role of aluminum powder in the reaction zone. In this paper, detonation driving process of HMX based aluminized explosive was studied by cylinder test, obtaining the expansion track of cylinder wall. In order to further research the reaction degree (λ) of aluminum in the reaction zone, the thermodynamic program VHL was used to calculate the detonation process at different reaction degrees, obtaining the parameters of detonation products thermodynamic state. Using the dynamic software LS-DYNA and the JWL equation of state by fitting the pressure and relative volume relationship, the cylinder test was simulated. Compared with the experimental results, when the reaction degree is 20%, the driving ability is found to be in agreement with measured ones. It is concluded that the driving ability of HMX based aluminized explosive can be more accurately characterized by considering the reaction degree of aluminum powder in the reaction zone.

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.

A three-dimensional finite element analysis of a passive and friction fit implant abutment interface and the influence of occlusal table dimension on the stress distribution pattern on the implant and surrounding bone

PubMed Central

Sarfaraz, Hasan; Paulose, Anoopa; Shenoy, K. Kamalakanth; Hussain, Akhter

2015-01-01

Aims: The aim of the study was to evaluate the stress distribution pattern in the implant and the surrounding bone for a passive and a friction fit implant abutment interface and to analyze the influence of occlusal table dimension on the stress generated. Materials and Methods: CAD models of two different types of implant abutment connections, the passive fit or the slip-fit represented by the Nobel Replace Tri-lobe connection and the friction fit or active fit represented by the Nobel active conical connection were made. The stress distribution pattern was studied at different occlusal dimension. Six models were constructed in PRO-ENGINEER 05 of the two implant abutment connection for three different occlusal dimensions each. The implant and abutment complex was placed in cortical and cancellous bone modeled using a computed tomography scan. This complex was subjected to a force of 100 N in the axial and oblique direction. The amount of stress and the pattern of stress generated were recorded on a color scale using ANSYS 13 software. Results: The results showed that overall maximum Von Misses stress on the bone is significantly less for friction fit than the passive fit in any loading conditions stresses on the implant were significantly higher for the friction fit than the passive fit. The narrow occlusal table models generated the least amount of stress on the implant abutment interface. Conclusion: It can thus be concluded that the conical connection distributes more stress to the implant body and dissipates less stress to the surrounding bone. A narrow occlusal table considerably reduces the occlusal overload. PMID:26929518

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.

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

Effect of milling time and annealing temperature on nanoparticles evolution for 13.5% Cr ODS ferritic steel powders by joint application of XAFS and TEM

NASA Astrophysics Data System (ADS)

He, P.; Hoffmann, J.; Möslang, A.

2018-04-01

The characteristics of strengthening nanoparticles have a major influence on the mechanical property and irradiation resistance of oxide dispersion strengthened (ODS) steels. To determine how to control nanoparticles evolution, 0.3% Ti with 0.3% Y2O3 were added in 13.5%Cr pre-alloyed steel powders via different milling and consolidation conditions, then characterized by transmission electron microscopy (TEM) and X-ray absorption fine structure (XAFS) at synchrotron irradiation facility. The dissolution of Y2O3 is greatly dependent on the milling time at fixed milling speeds. After 24 h of milling, only minor amounts of the initially added Y2O3 dissolve into the steel matrix whereas TEM results reveal nearly complete dissolution of Y2O3 in 80-h-milled powder. The annealed powder FT-A800 (at 800 °C for 1 h) exhibits a structure near to the initially added Y2O3. The slightly deviation may be accounted for considerable lattice distortion related to the presence of atomic vacancies or formation of Y-Ti-O nucleus. The annealed powders FT-A1000 and FT-A1100 contain complex mixtures of Y-O/Y-Ti-O oxides, which cannot be fitted by any single thermally stable compounds. The coordination numbers of these first two shells in the annealed powders significantly raise as a function of the annealing temperature, indicating the formation of more ordered Y-O or Y-Ti-O particles. The extended X-ray absorption fine structure (EXAFS) spectrum could not necessarily distinguish the dominant oxide species.

Fitting direct covariance structures by the MSTRUCT modeling language of the CALIS procedure.

PubMed

Yung, Yiu-Fai; Browne, Michael W; Zhang, Wei

2015-02-01

This paper demonstrates the usefulness and flexibility of the general structural equation modelling (SEM) approach to fitting direct covariance patterns or structures (as opposed to fitting implied covariance structures from functional relationships among variables). In particular, the MSTRUCT modelling language (or syntax) of the CALIS procedure (SAS/STAT version 9.22 or later: SAS Institute, 2010) is used to illustrate the SEM approach. The MSTRUCT modelling language supports a direct covariance pattern specification of each covariance element. It also supports the input of additional independent and dependent parameters. Model tests, fit statistics, estimates, and their standard errors are then produced under the general SEM framework. By using numerical and computational examples, the following tests of basic covariance patterns are illustrated: sphericity, compound symmetry, and multiple-group covariance patterns. Specification and testing of two complex correlation structures, the circumplex pattern and the composite direct product models with or without composite errors and scales, are also illustrated by the MSTRUCT syntax. It is concluded that the SEM approach offers a general and flexible modelling of direct covariance and correlation patterns. In conjunction with the use of SAS macros, the MSTRUCT syntax provides an easy-to-use interface for specifying and fitting complex covariance and correlation structures, even when the number of variables or parameters becomes large. © 2014 The British Psychological Society.

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.

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.

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.

Benzene carboxylic acid derivatized graphene oxide nanosheets on natural zeolites as effective adsorbents for cationic dye removal.

PubMed

Yu, Yang; Murthy, Bandaru N; Shapter, Joseph G; Constantopoulos, Kristina T; Voelcker, Nicolas H; Ellis, Amanda V

2013-09-15

Graphene oxide (GO) nanosheets were grafted to acid-treated natural clinoptilolite-rich zeolite powders followed by a coupling reaction with a diazonium salt (4-carboxybenzenediazoniumtetrafluoroborate) to the GO surface. Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) revealed successful grafting of GO nanosheets onto the zeolite surface. The application of the adsorbents for the adsorption of rhodamine B from aqueous solutions was then demonstrated. After reaching adsorption equilibrium the maximum adsorption capacities were shown to be 50.25, 55.56 and 67.56 mg g(-1) for pristine natural zeolite, GO grafted zeolite (GO-zeolite) and benzene carboxylic acid derivatized GO-zeolite powders, respectively. The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. Further, a relationship between surface functional groups, pH and adsorption efficiency was established. Results indicate that benzene carboxylic acid derivatized GO-zeolite powders are environmentally favorable adsorbents for the removal of cationic dyes from aqueous solutions. Copyright © 2013 Elsevier B.V. All rights reserved.

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.

Ceria modified activated carbon: an efficient arsenic removal adsorbent for drinking water purification

NASA Astrophysics Data System (ADS)

Sawana, Radha; Somasundar, Yogesh; Iyer, Venkatesh Shankar; Baruwati, Babita

2017-06-01

Ceria (CeO2) coated powdered activated carbon was synthesized by a single step chemical process and demonstrated to be a highly efficient adsorbent for the removal of both As(III) and As(V) from water without any pre-oxidation process. The formation of CeO2 on the surface of powdered activated carbon was confirmed by X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. The percentage of Ce in the adsorbent was confirmed to be 3.5 % by ICP-OES. The maximum removal capacity for As(III) and As(V) was found to be 10.3 and 12.2 mg/g, respectively. These values are comparable to most of the commercially available adsorbents. 80 % of the removal process was completed within 15 min of contact time in a batch process. More than 95 % removal of both As(III) and As(V) was achieved within an hour. The efficiency of removal was not affected by change in pH (5-9), salinity, hardness, organic (1-4 ppm of humic acid) and inorganic anions (sulphate, nitrate, chloride, bicarbonate and fluoride) excluding phosphate. Presence of 100 ppm phosphate reduced the removal significantly from 90 to 18 %. The equilibrium adsorption pattern of both As(III) and As(V) fitted well with the Freundlich model with R 2 values 0.99 and 0.97, respectively. The material shows reusability greater than three times in a batch process (arsenic concentration reduced below 10 ppb from 330 ppb) and a life of at least 100 L in a column study with 80 g material when tested under natural hard water (TDS 1000 ppm, pH 7.8, hardness 600 ppm as CaCO3) spiked with 330 ppb of arsenic.

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.

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)

Extracting Fitness Relationships and Oncogenic Patterns among Driver Genes in Cancer.

PubMed

Zhang, Xindong; Gao, Lin; Jia, Songwei

2017-12-25

Driver mutation provides fitness advantage to cancer cells, the accumulation of which increases the fitness of cancer cells and accelerates cancer progression. This work seeks to extract patterns accumulated by driver genes ("fitness relationships") in tumorigenesis. We introduce a network-based method for extracting the fitness relationships of driver genes by modeling the network properties of the "fitness" of cancer cells. Colon adenocarcinoma (COAD) and skin cutaneous malignant melanoma (SKCM) are employed as case studies. Consistent results derived from different background networks suggest the reliability of the identified fitness relationships. Additionally co-occurrence analysis and pathway analysis reveal the functional significance of the fitness relationships with signaling transduction. In addition, a subset of driver genes called the "fitness core" is recognized for each case. Further analyses indicate the functional importance of the fitness core in carcinogenesis, and provide potential therapeutic opportunities in medicinal intervention. Fitness relationships characterize the functional continuity among driver genes in carcinogenesis, and suggest new insights in understanding the oncogenic mechanisms of cancers, as well as providing guiding information for medicinal intervention.

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.

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,…

Electrochemical to Mechanical Energy Conversion

DTIC Science & Technology

2010-02-01

advantage of these properties . Metal alloys fit these requirements as many of them dilate in excess of 100% when alloyed with lithium. Aluminum, in...3. Woo KC, Kamitakahara WA, DiVincenzo DP, et al . Effect of In-Plane Density on the Structural and Elastic Properties of Graphite Intercalation...Further, free volume associated with the powder packing of the electrodes or the sealing process will aid in stress relaxation and creep strain. (a) (b) 35

Biosorption of hexavalent chromium from aqueous solutions by Macadamia nutshell powder

NASA Astrophysics Data System (ADS)

Pakade, Vusumzi Emmanuel; Ntuli, Themba Dominic; Ofomaja, Augustine Enakpodia

2017-10-01

Macadamia nutshell biosorbents treated in three different activating agents [raw Macadamia nutshell powder (RMN), acid-treated Macadamia nutshell (ATMN) and base-treated Macadamia nutshell (BTMN)] were investigated for the adsorption of hexavalent chromium [Cr(VI)] from aqueous solutions. Fourier transform infrared spectroscopy spectra of free and Cr(VI)-loaded sorbents as well as thermogravimetric analysis revealed that the acid and base treatments modified the surface properties of the sorbent. Surface characteristics were also evaluated by the scanning electron microscopy and surface area analyzer. The optimum conditions for the adsorption of Cr(VI) by sorbents were pH 2, contact time 10 h, adsorbent mass 0.2 g and concentration 100 mg L-1. The equilibrium data were fitted into the Langmuir, Freundlich, Redlich-Peterson and Sips isotherms, and no single model could clearly explain the sorption mechanism. Maximum binding capacities of 45.23, 44.83 and 42.44 mg g-1 for RMN, ATMN and BTMN, respectively, were obtained. The kinetic data were analyzed using the pseudo-first, pseudo-second and Elovich kinetic models, and it was observed that the pseudo-second-order model produced the best fit for the experimental data. Macadamia nutshell sorbents showed potential as low-cost adsorbent for the removal of Cr(VI) from aqueous solution.

Advanced Spectral Analysis Program (ASAP) for High-Pressure X-ray Diffraction

NASA Astrophysics Data System (ADS)

Montgomery, Jeffrey

A program for analyzing large powder diffraction data sets has been developed. This tool enables the user to fit any type of crystal structure by indexing peaks in multiple files simultaneously by manually selecting them from a 2D plot of peak positions. The program has tools for automatic peak fitting and pressure determination using various equations of state. The interface is useful for correlating information from various types of spectral data, and so tools have been added for analyzing common fluorescence markers such as ruby, strontium tetraborate, and diamond. The program operation is demonstrated by the analysis of high-pressure powder x-ray diffraction data taken on a sample of vanadium metal at the Advanced Photon Source 16-BMD beamline. Samples were compressed in three runs to a pressure of 70 GPa in an attempt to measure the phase transition from bcc to orthorhombic in hydrostatic and non-hydrostatic conditions. Using ASAP to analyze this data provides a fast and accurate tool for observation of such a subtle transition, which is characterized primarily by a narrow splitting of the bcc 110 and 112 peaks. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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.

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 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.

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.

Shifts in reproductive assurance strategies and inbreeding costs associated with habitat fragmentation in Central American mahogany

PubMed Central

Breed, Martin F; Gardner, Michael G; Ottewell, Kym M; Navarro, Carlos M; Lowe, Andrew J

2012-01-01

The influence of habitat fragmentation on mating patterns and progeny fitness in trees is critical for understanding the long-term impact of contemporary landscape change on the sustainability of biodiversity. We examined the relationship between mating patterns, using microsatellites, and fitness of progeny, in a common garden trial, for the insect-pollinated big-leaf mahogany, Swietenia macrophylla King, sourced from forests and isolated trees in 16 populations across Central America. As expected, isolated trees had disrupted mating patterns and reduced fitness. However, for dry provenances, fitness was negatively related to correlated paternity, while for mesic provenances, fitness was correlated positively with outcrossing rate and negatively with correlated paternity. Poorer performance of mesic provenances is likely because of reduced effective pollen donor density due to poorer environmental suitability and greater disturbance history. Our results demonstrate a differential shift in reproductive assurance and inbreeding costs in mahogany, driven by exploitation history and contemporary landscape context. PMID:22381041

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.

NMR spectrum analysis for CrAs at ambient pressure

NASA Astrophysics Data System (ADS)

Kotegawa, H.; Nakahara, S.; Matsushima, K.; Tou, H.; Matsuoka, E.; Sugawara, H.; Harima, H.

2018-05-01

We report NMR spectrum analysis for CrAs, which was recently reported to be superconducting under pressure. The NMR spectrum obtained by the powdered single crystals shows a typical powder pattern reproduced by the electric field gradient (EFG) parameters and isotropic Knight shift, indicating anisotropy of Knight shift is not remarkable in CrAs. For the oriented sample, the spectrum can be understood by considering that the crystals are aligned for H ∥ b . The temperature dependence of Knight shift was successfully obtained from NMR spectrum with large nuclear quadrupole interaction.

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.

Probing Sub-atomistic Free-Volume Imperfections in Dry-Milled Nanoarsenicals with PAL Spectroscopy.

PubMed

Shpotyuk, Oleh; Ingram, Adam; Bujňáková, Zdenka; Baláž, Peter; Shpotyuk, Yaroslav

2016-12-01

Structural transformations caused by coarse-grained powdering and fine-grained mechanochemical milling in a dry mode were probed in high-temperature modification of tetra-arsenic tetra-sulfide known as β-As4S4. In respect to X-ray diffraction analysis, the characteristic sizes of β-As4S4 crystallites in these coarse- and fine-grained powdered pellets were 90 and 40 nm, respectively. Positron annihilation lifetime spectroscopy was employed to characterize transformations occurred in free-volume structure of these nanoarsenicals. Experimentally measured positron lifetime spectra were parameterized in respect to three- or two-term fitting procedures and respectively compared with those accumulated for single crystalline realgar α-As4S4 polymorph. The effect of coarse-grained powdering was found to result in generation of large amount of positron and positronium Ps trapping sites inside arsenicals in addition to existing ones. In fine-grained powdered β-As4S4 pellets, the positron trapping sites with characteristic free volumes close to bi- and tri-atomic vacancies were evidently dominated. These defects were supposed to originate from grain boundary regions and interfacial free volumes near aggregated β-As4S4 crystallites. Thus, the cumulative production of different positron traps with lifetimes close to defect-related lifetimes in realgar α-As4S4 polymorph was detected in fine-grained milled samples.

Industrial yogurt manufacture: monitoring of fermentation process and improvement of final product quality.

PubMed

Soukoulis, C; Panagiotidis, P; Koureli, R; Tzia, C

2007-06-01

Lactic acid fermentation during the production of skim milk and whole fat set-style yogurt was continuously monitored by measuring pH. The modified Gompertz model was successfully applied to describe the pH decline and viscosity development during the fermentation process. The viscosity and incubation time data were also fitted to linear models against ln(pH). The investigation of the yogurt quality improvement practices included 2 different heat treatments (80 degrees C for 30 min and 95 degrees C for 10 min), 3 milk protein fortifying agents (skim milk powder, whey powder, and milk protein concentrate) added at 2.0%, and 4 hydrocolloids (kappa-carrageenan, xanthan, guar gum, and pectin) added at 0.01% to whole fat and skim yogurts. Heat treatment significantly affected viscosity and acetaldehyde development without influencing incubation time and acidity. The addition of whey powder shortened the incubation time but had a detrimental effect on consistency, firmness, and overall acceptance of yogurts. On the other hand, addition of skim milk powder improved the textural quality and decreased the vulnerability of yogurts to syneresis. Anionic stabilizers (kappa-carrageenan and pectin) had a poor effect on the texture and palatability of yogurts. However, neutral gums (xanthan and guar gum) improved texture and prevented the wheying-off defect. Skim milk yogurts exhibited longer incubation times and higher viscosities, whereas they were rated higher during sensory evaluation than whole fat yogurts.

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.

Dielectric relaxation in AC powder electroluminescent devices

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Su, Haibin; Tan, Chuan Seng; Wong, Terence Kin Shun; Teo, Ronnie Jin Wah

2017-01-01

The dielectric properties of AC powder electroluminescent devices were measured and analyzed using complex impedance spectroscopy to determine the relaxation processes occurring within the devices. The relaxation processes identified were ascribed to the electrode polarization caused by ion accumulation at the electrode/resin interfaces, the Maxwell-Wagner-Sillars effects at the (ZnS or BaTiO3) particle/resin interfaces, and the dipolar reorientation of polymer chains in the resin matrix. Each relaxation process was represented by its corresponding equivalent circuit component. Space charge polarization at the electrodes were represented by a Warburg element, a resistor, and a constant phase element. The resin matrix, ZnS/resin and BaTiO3/resin interfaces could each be modeled by a resistor and a capacitor in parallel. The simulated equivalent circuits for three different printed structures showed good fitting with their experimental impedance results.

Studies of ferroelectric and dielectric properties of pure and doped barium titanate prepared by sol-gel method

NASA Astrophysics Data System (ADS)

Bisen, Supriya; Mishra, Ashutosh; Jarabana, Kanaka M.

2016-05-01

In this work, Barium Titanate (BaTiO3) powders were synthesized via Sol-Gel auto combustion method using citric acid as a chelating agent. We study the behavior of ferroelectric and dielectric properties of pure and doped BaTiO3 on different concentration. To understand the phase and structure of the powder calcined at 900°C were characterized by X-ray Diffraction shows that tetragonal phase is dominant for pure and doped BTO and data fitted by Rietveld Refinement. Electric and Dielectric properties were characterized by P-E Hysteresis and Dielectric measurement. In P-E measurement ferroelectric loop tracer applied for different voltage. The temperature dependant dielectric constant behavior was observed as a function of frequency recorded on hp-Hewlett Packard 4192A, LF impedance, 5Hz-13Hz analyzer.

Compact low power infrared tube furnace for in situ X-ray powder diffraction

NASA Astrophysics Data System (ADS)

Doran, A.; Schlicker, L.; Beavers, C. M.; Bhat, S.; Bekheet, M. F.; Gurlo, A.

2017-01-01

We describe the development and implementation of a compact, low power, infrared heated tube furnace for in situ powder X-ray diffraction experiments. Our silicon carbide (SiC) based furnace design exhibits outstanding thermal performance in terms of accuracy control and temperature ramping rates while simultaneously being easy to use, robust to abuse and, due to its small size and low power, producing minimal impact on surrounding equipment. Temperatures in air in excess of 1100 °C can be controlled at an accuracy of better than 1%, with temperature ramping rates up to 100 °C/s. The complete "add-in" device, minus power supply, fits in a cylindrical volume approximately 15 cm long and 6 cm in diameter and resides as close as 1 cm from other sensitive components of our experimental synchrotron endstation without adverse effects.

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.

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.

[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%.

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.

Selective sweeps in growing microbial colonies

NASA Astrophysics Data System (ADS)

Korolev, Kirill S.; Müller, Melanie J. I.; Karahan, Nilay; Murray, Andrew W.; Hallatschek, Oskar; Nelson, David R.

2012-04-01

Evolutionary experiments with microbes are a powerful tool to study mutations and natural selection. These experiments, however, are often limited to the well-mixed environments of a test tube or a chemostat. Since spatial organization can significantly affect evolutionary dynamics, the need is growing for evolutionary experiments in spatially structured environments. The surface of a Petri dish provides such an environment, but a more detailed understanding of microbial growth on Petri dishes is necessary to interpret such experiments. We formulate a simple deterministic reaction-diffusion model, which successfully predicts the spatial patterns created by two competing species during colony expansion. We also derive the shape of these patterns analytically without relying on microscopic details of the model. In particular, we find that the relative fitness of two microbial strains can be estimated from the logarithmic spirals created by selective sweeps. The theory is tested with strains of the budding yeast Saccharomyces cerevisiae for spatial competitions with different initial conditions and for a range of relative fitnesses. The reaction-diffusion model also connects the microscopic parameters like growth rates and diffusion constants with macroscopic spatial patterns and predicts the relationship between fitness in liquid cultures and on Petri dishes, which we confirmed experimentally. Spatial sector patterns therefore provide an alternative fitness assay to the commonly used liquid culture fitness assays.

Synthesis and structural characterization of bulk Sb2Te3 single crystal

NASA Astrophysics Data System (ADS)

Sultana, Rabia; Gahtori, Bhasker; Meena, R. S.; Awana, V. P. S.

2018-05-01

We report the growth and characterization of bulk Sb2Te3 single crystal synthesized by the self flux method via solid state reaction route from high temperature melt (850˚C) and slow cooling (2˚C/hour) of constituent elements. The single crystal X-ray diffraction pattern showed the 00l alignment and the high crystalline nature of the resultant sample. The rietveld fitted room temperature powder XRD revealed the phase purity and rhombohedral structure of the synthesized crystal. The formation and analysis of unit cell structure further verified the rhombohedral structure composed of three quintuple layers stacked one over the other. The SEM image showed the layered directional growth of the synthesized crystal carried out using the ZEISS-EVOMA-10 scanning electron microscope The electrical resistivity measurement was carried out using the conventional four-probe method on a quantum design Physical Property Measurement System (PPMS). The temperature dependent electrical resistivity plot for studied Sb2Te3 single crystal depicts metallic behaviour in the absence of any applied magnetic field. The synthesis as well as the structural characterization of as grown Sb2Te3 single crystal is reported and discussed in the present letter.

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

Osiry, H.; Cano, A.; Lemus-Santana, A.A.

This contribution discusses the intercalation of imidazole and its 2-ethyl derivative, and pyridine in 2D copper nitroprusside. In the interlayer region, neighboring molecules remain interacting throu gh their dipole and quadrupole moments, which supports the solid 3D crystal structure. The crystal structure of this series of intercalation compounds was solved and refined from powder X-ray diffraction patterns complemented with spectroscopic information. The intermolecular interactions were studied from the refined crystal structures and low temperature magnetic measurements. Due to strong attractive forces between neighboring molecules, the resulting π–π cloud overlapping enables the ferromagnetic coupling between metal centers on neighboring layers, which wasmore » actually observed for the solids containing imidazole and pyridine as intercalated molecules. For these two solids, the magnetic data were properly described with a model of six neighbors. For the solid containing 2-ethylimidazole and for 2D copper nitroprusside, a model of four neighbors in a plane is sufficient to obtain a reliable data fitting. - Highlights: • Intercalation of organic molecules in 2D copper (II) nitroprusside. • Molecular properties of intercalation compounds of 2D copper (II) nitroprusside. • Magnetic properties of hybrid inorganic–organic solids. • Hybrid inorganic–organic 3D framework.« less

Statistical Optimization of Reactive Plasma Cladding to Synthesize a WC-Reinforced Fe-Based Alloy Coating

NASA Astrophysics Data System (ADS)

Wang, Miqi; Zhou, Zehua; Wu, Lintao; Ding, Ying; Xu, Feilong; Wang, Zehua

2018-04-01

A new compound Fe-W-C powder for reactive plasma cladding was fabricated by precursor carbonization process using sucrose as a precursor. The application of quadratic general rotary unitized design was highlighted to develop a mathematical model to predict and accomplish the desired surface hardness of plasma-cladded coating. The microstructure and microhardness of the coating with optimal parameters were also investigated. According to the developed empirical model, the optimal process parameters were determined as follows: 1.4 for C/W atomic ratio, 20 wt.% for W content, 130 A for scanning current and 100 mm/min (1.67 mm/s) for scanning rate. The confidence level of the model was 99% according to the results of the F-test and lack-of-fit test. Microstructural study showed that the dendritic structure was comprised of a mechanical mixture of α-Fe and carbides, while the interdendritic structure was a eutectic of α-Fe and carbides in the composite coating with optimal parameters. WC phase generation can be confirmed from the XRD pattern. Due to good preparation parameters, the average microhardness of cladded coating can reach 1120 HV0.1, which was four times the substrate microhardness.

Occupational stress, Type A behavior, and physical well being.

PubMed

Ivancevich, J M; Matteson, M T; Preston, C

1982-06-01

In the context of a person-environment fit framework, organizational level and the Type A behavior pattern of managers were found to moderate the stressor, satisfaction, and physiology associations. For nurses, Type A behavior pattern was a much more significant moderator of the person-environment fit than were the nurses' specialty work activities.

EVALUATING EFFECTS OF LOW QUALITY HABITATS ON REGIONAL GROWTH IN PEOMYCUS LEUCOPUS: INSIGHTS FROM FIELD-PARAMETERIZED SPATIAL MATRIX MODELS.

EPA Science Inventory

Due to complex population dynamics and source-sink metapopulation processes, animal fitness sometimes varies across landscapes in ways that cannot be deduced from simple density patterns. In this study, we examine spatial patterns in fitness using a combination of intensive fiel...

Fit of pressed crowns fabricated from two CAD-CAM wax pattern process plans: A comparative in vitro study.

PubMed

Shamseddine, Loubna; Mortada, Rola; Rifai, Khaldoun; Chidiac, Jose Johann

2017-07-01

Subtractive and additive computer-aided design and computer-aided manufacturing (CAD-CAM) wax pattern processing are 2 methods of fabricating a pressed ceramic crown. Whether a subtractive milled wax pattern or a pattern from the micro-stereolithography additive process produces lithium disilicate crowns with better marginal and internal fit is unclear. Ten silicone impressions were made for a prepared canine tooth. Each die received 2 lithium disilicate (IPS e.max) copings, 1 from milled wax blocks and 1 from additive wax. The replica technique was used to measure the fit by scanning electron microscopy at ×80 magnification. Collected data were analyzed using the paired Student t test for the marginal and internal fit. For the occlusal fit, the difference in scores did not follow a normal distribution, and the Wilcoxon signed rank test was used (α=.05). The mean marginal, axial, and occlusal fit showed no significant differences when the 2 CAD-CAM manufacturing processes were compared (P>.05). For the marginal fit, the mean (±SD) values were 105.1 μm ±39.6 with the milled process and 126.2 μm ±25.2 for the additive process. The mean values were 98.1 μm ±26.1 for the axial fit in the milled process and 106.8 μm ±21.2 in the additive process. For the occlusal fit, median values (interquartile interval) were 199.0 μm (141.5 to 269.9) for subtractive manufacturing and 257.2 μm (171.6 to 266.0) for micro-SLA manufacturing. No significant difference was found between the fit of the 2 techniques. The mean values of axial and occlusal median values were 10 and 5 to 6 times greater than machine's nominal values. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

The Many Null Distributions of Person Fit Indices.

ERIC Educational Resources Information Center

Molenaar, Ivo W.; Hoijtink, Herbert

1990-01-01

Statistical properties of person fit indices are reviewed as indicators of the extent to which a person's score pattern is in agreement with a measurement model. Distribution of a fit index and ability-free fit evaluation are discussed. The null distribution was simulated for a test of 20 items. (SLD)

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.

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

Lepton mixing patterns from the group Σ (36 ×3 ) with a generalized C P transformation

NASA Astrophysics Data System (ADS)

Rong, Shu-jun

2017-04-01

The group Σ (36 ×3 ) with the generalized C P transformation is introduced to predict the mixing pattern of leptons. Various combinations of Abelian residual flavor symmetries with C P transformations are surveyed. Six mixing patterns could accommodate the fit data of neutrinos oscillation at the 3 σ level. Among them, two patterns predict the nontrivial Dirac C P phase, around ±5 7 ° or ±12 3 ° , which is in accordance with the result of the literature and the recent fit data. Furthermore, one pattern could satisfy the experimental constraints at the 1 σ level.

EXAFS Study on LiFePO4 Powders Produced From Two Sol-Gel Routes

NASA Astrophysics Data System (ADS)

Negara, V. S. I.; Latif, C.; Wongtepa, W.; Pratapa, S.

2018-04-01

The local structure of LiFePO4 powders has been investigated using Fe K-edge Extended X-Ray Absorption Fine Structure (EXAFS) Spectroscopy data. The synthesis of LFP powders was carried out using two different sol-gel methods. The raw materials for Fe source were ironstone and commercial precursor of FeCl2·4H2O. Synthesis using natural materials produced two phases, namely LiFePO4 olivine and Li3Fe2(PO4)3 nasicon, whereas that using a commercial product produced a single phase of LiFePO4 olivine. The EXAFS data for both samples were collected at Synchrotron Light Research Institute (SLRI), Thailand. Fitting of the model on the experimental curve provided parameters that can be interpreted as the distance between Fe as the absorber and the nearest atoms on the LFP materials. The EXAFS data analysis has shown that synthesis of LFPs using different Fe sources gives slightly different nearest-neighbor distances, namely Fe-O of 0.21% -0.23%, Fe-P of 0.14% - 0.16%, Fe-Fe of 0.12% for both samples, respectively.

Feeling right is feeling good: psychological well-being and emotional fit with culture in autonomy- versus relatedness-promoting situations.

PubMed

De Leersnyder, Jozefien; Kim, Heejung; Mesquita, Batja

2015-01-01

The current research tested the idea that it is the cultural fit of emotions, rather than certain emotions per se, that predicts psychological well-being. We reasoned that emotional fit in the domains of life that afford the realization of central cultural mandates would be particularly important to psychological well-being. We tested this hypothesis with samples from three cultural contexts that are known to differ with respect to their main cultural mandates: a European American (N = 30), a Korean (N = 80), and a Belgian sample (N = 266). Cultural fit was measured by comparing an individual's patterns of emotions to the average cultural pattern for the same type of situation on the Emotional Patterns Questionnaire (De Leersnyder et al., 2011). Consistent with our hypothesis, we found evidence for "universality without uniformity": in each sample, psychological well-being was associated with emotional fit in the domain that was key to the cultural mandate. However, cultures varied with regard to the particular domain involved. Psychological well-being was predicted by emotional fit (a) in autonomy-promoting situations at work in the U.S., (b) in relatedness-promoting situations at home in Korea, and (c) in both autonomy-promoting and relatedness-promoting situations in Belgium. These findings show that the experience of culturally appropriate patterns of emotions contributes to psychological well-being. One interpretation is that experiencing appropriate emotions is itself a realization of the cultural mandates.

Feeling right is feeling good: psychological well-being and emotional fit with culture in autonomy- versus relatedness-promoting situations

PubMed Central

De Leersnyder, Jozefien; Kim, Heejung; Mesquita, Batja

2015-01-01

The current research tested the idea that it is the cultural fit of emotions, rather than certain emotions per se, that predicts psychological well-being. We reasoned that emotional fit in the domains of life that afford the realization of central cultural mandates would be particularly important to psychological well-being. We tested this hypothesis with samples from three cultural contexts that are known to differ with respect to their main cultural mandates: a European American (N = 30), a Korean (N = 80), and a Belgian sample (N = 266). Cultural fit was measured by comparing an individual’s patterns of emotions to the average cultural pattern for the same type of situation on the Emotional Patterns Questionnaire (De Leersnyder et al., 2011). Consistent with our hypothesis, we found evidence for “universality without uniformity”: in each sample, psychological well-being was associated with emotional fit in the domain that was key to the cultural mandate. However, cultures varied with regard to the particular domain involved. Psychological well-being was predicted by emotional fit (a) in autonomy-promoting situations at work in the U.S., (b) in relatedness-promoting situations at home in Korea, and (c) in both autonomy-promoting and relatedness-promoting situations in Belgium. These findings show that the experience of culturally appropriate patterns of emotions contributes to psychological well-being. One interpretation is that experiencing appropriate emotions is itself a realization of the cultural mandates. PMID:26042063

A comparative study of roll compaction of free-flowing and cohesive pharmaceutical powders.

PubMed

Yu, Shen; Gururajan, Bindhu; Reynolds, Gavin; Roberts, Ron; Adams, Michael J; Wu, Chuan-Yu

2012-05-30

Roll compaction is widely adopted as a dry granulation method in the pharmaceutical industry. The roll compaction behaviour of feed powders is primarily governed by two parameters: the maximum pressure and the nip angle. Although the maximum pressure can be measured directly using pressure sensors fitted in the rolls, it is not a trivial task to determine the nip angle, which is a measure of the size of the compaction zone and hence the degree of compression. Thus a robust approach based upon the calculation of the pressure gradient, which can be obtained directly from experiments using an instrumented roll compactor, was developed. It has been shown that the resulting nip angles are comparable to those obtained using the methods reported in literature. Nevertheless, the proposed approach has distinctive advantages including (1) it is based on the intrinsic features of slip and no-slip interactions between the powder and roll surface and (2) it is not necessary to carry out wall friction measurements that involve plates that may not be representative of the roll compactor in terms of the surface topography and surface energy. The method was evaluated by investigating the effect of roll speed for two pharmaceutical excipients with distinctive material properties: microcrystalline cellulose (MCC) and di-calcium phosphate dihydrate (DCPD). It was found that the maximum pressure and nip angle for DCPD, which is a cohesive powder, decrease sharply with increasing roll speed whereas they are essentially independent of roll speed for MCC, which is an easy flowing powder. The roll compaction behaviour of MCC-DCPD mixtures with various compositions was also investigated in order to evaluate the effect of flowability. It was found that the nip angle and maximum pressure generally increased with improved flowability of the feed powders. Copyright © 2012 Elsevier B.V. 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.

Exploiting the Adaptation Dynamics to Predict the Distribution of Beneficial Fitness Effects

PubMed Central

2016-01-01

Adaptation of asexual populations is driven by beneficial mutations and therefore the dynamics of this process, besides other factors, depends on the distribution of beneficial fitness effects. It is known that on uncorrelated fitness landscapes, this distribution can only be of three types: truncated, exponential and power law. We performed extensive stochastic simulations to study the adaptation dynamics on rugged fitness landscapes, and identified two quantities that can be used to distinguish the underlying distribution of beneficial fitness effects. The first quantity studied here is the fitness difference between successive mutations that spread in the population, which is found to decrease in the case of truncated distributions, remains nearly a constant for exponentially decaying distributions and increases when the fitness distribution decays as a power law. The second quantity of interest, namely, the rate of change of fitness with time also shows quantitatively different behaviour for different beneficial fitness distributions. The patterns displayed by the two aforementioned quantities are found to hold good for both low and high mutation rates. We discuss how these patterns can be exploited to determine the distribution of beneficial fitness effects in microbial experiments. PMID:26990188

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.

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.

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.

Stage Costumes for Girls.

ERIC Educational Resources Information Center

Greenhowe, Jean

This book contains full instructions for making 14 costumes for girls to fit any sizes up to about 147 cm (4 feet 10 inches) in height. All the garments can be made to fit any child's individual measurements without the need of complicated pattern pieces. Simple basic shapes such as rectangles and circles are used for the patterns and the only…

Studies of ferroelectric and dielectric properties of pure and doped barium titanate prepared by sol-gel method

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

Bisen, Supriya; Mishra, Ashutosh; Jarabana, Kanaka M.

2016-05-23

In this work, Barium Titanate (BaTiO{sub 3}) powders were synthesized via Sol-Gel auto combustion method using citric acid as a chelating agent. We study the behavior of ferroelectric and dielectric properties of pure and doped BaTiO{sub 3} on different concentration. To understand the phase and structure of the powder calcined at 900°C were characterized by X-ray Diffraction shows that tetragonal phase is dominant for pure and doped BTO and data fitted by Rietveld Refinement. Electric and Dielectric properties were characterized by P-E Hysteresis and Dielectric measurement. In P-E measurement ferroelectric loop tracer applied for different voltage. The temperature dependant dielectricmore » constant behavior was observed as a function of frequency recorded on hp-Hewlett Packard 4192A, LF impedance, 5Hz-13Hz analyzer.« less

Flexible high-temperature pH probe

DOEpatents

Bielawski, John C.; Outwater, John O.; Halbfinger, George P.

2003-04-22

A flexible pH probe device is provided for use in hot water and other high temperature environments up to about 590.degree. F. The pH probe includes a flexible, inert tubular probe member, an oxygen anion conducting, solid state electrolyte plug located at the distal end of the tubular member, oxide powder disposed at the distal end of the tubular member; a metal wire extending along the tubular member and having a distal end in contact with the oxide powder so as to form therewith an internal reference electrode; and a compression fitting forming a pressure boundary seal around a portion of the tubular member remote from the distal end thereof. Preferably, the tubular member is made of polytetrafluoroethylene, and the solid state electrolyte plug is made of stabilized zirconia. The flexibility of the probe member enables placement of the electrode into the area of interest, including around corners, into confined areas and the like.

Fine structure of the amide i band in acetanilide

NASA Astrophysics Data System (ADS)

Careri, G.; Gratton, E.; Shyamsunder, E.

1988-05-01

Their absorption spectrum of both single crystals and powdered samples of acetanilide (a model system for proteins) has been studied in the amide i region, where a narrow band has been identified as a highly trapped soliton state. The powder-sample spectra have been decomposed using four Lorentzian bands. A strong temperature dependence has been found for the intensity of two of the subbands, which also show a complementary behavior. Polarization studies performed on thin crystals have shown that the subbands have the same polarization. Low-temperature spectra of partially deuterated samples show the presence of the subbands at the same absorption frequencies found using the fitting procedure in the spectra of nondeuterated samples. The soliton model currently proposed to explain the origin of the anomalous amide i component at 1650 cm-1 still holds, but some modification of the model is required to account for the new features revealed by this study.

Mesoporous Nitrogen Doped Carbon-Glass Ceramic Cathode for High Performance Lithium-Oxygen Battery

DTIC Science & Technology

2012-06-01

dry room with controlled moisture content. Composite 3 films on nickel foam were used as working cathodes along with lithium metal as anode and the...cathode formulation [6,7,8,9,10], efficient oxygen reduction catalysts [11,12], electrolyte compositions [13,14], effect of moisture [15], etc...specimens. Structure and purity of these materials were performed by powder X-ray diffraction (XRD) on a Rigaku D/MAX-2250 diffractometer fitted with CuKα

Program to Develop High Strength Aluminum Powder Metallurgy Mill Products - Phase IV-B-Scale - up to 3200 lb Billet

DTIC Science & Technology

1977-04-25

H . Dudas and J . Paul Lyle, Jr. as project supervisors. The Frankford Arsenal Project Engineer...container was controlled to minimize dust emissions through any of the seals in the complete assembly. A gas bypass line allowed the displaced gas in...2) the cylinder, a shrink fit assembly of an H -12 steel liner and two outer retaining rings; and (3) a ram assembly consisting of a ram nose,

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.

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.

Impact of Striped-Squirrel Nectar-Robbing Behaviour on Gender Fitness in Alpinia roxburghii Sweet (Zingiberaceae).

PubMed

Deng, Xiaobao; Mohandass, Dharmalingam; Katabuchi, Masatoshi; Hughes, Alice C; Roubik, David W

2015-01-01

Nectar-robbing has the potential to strongly affect male and female reproductive fitness of plants. One example of nectar theft is that shown by striped-squirrels (Tamiops swinhoei) on a number of ginger species, including Alpinia roxburghii and A. kwangsiensis (Zingiberaceae). In this study, we used a fluorescent dye as a pollen analogue, and measured fruit and seed output, to test the effect of squirrel nectar-robbing on A. roxburghii reproductive fitness. Pollen transfer between robbed and unrobbed flowers was assessed by comparing 60 randomly established plots containing robbed and unrobbed flowers. The frequency of squirrel robbing visits and broken styles were recorded from a number of flowers for five consecutive days. Two bee species (Bombus eximius and Apis cerana), were the primary pollinators, and their visitation frequency was recorded for six consecutive days. The results showed that fluorescent powder from unrobbed flowers was dispersed further, and to a greater number of flowers than that placed on robbed flowers. Additionally, robbing flowers caused significant damage to reproductive organs, resulting in lower fruit and seed sets in robbed than in unrobbed flowers and influencing both male and female fitness. The frequency of the primary pollinator visits (B. eximius) was significantly higher for unrobbed plants than for robbed plants. The present study clearly shows the negative impact of squirrel robbing on A. roxburghii male reproductive fitness and neutral impact on female reproductive fitness.

Development of the FitSight Fitness Tracker to Increase Time Outdoors to Prevent Myopia.

PubMed

Verkicharla, Pavan K; Ramamurthy, Dharani; Nguyen, Quang Duc; Zhang, Xinquan; Pu, Suan-Hui; Malhotra, Rahul; Ostbye, Truls; Lamoureux, Ecosse L; Saw, Seang-Mei

2017-06-01

To develop a fitness tracker (FitSight) to encourage children to increase time spent outdoors. To evaluate the wear pattern for this tracker and outdoor time pattern by estimating light illumination levels among children. The development of the FitSight fitness tracker involved the designing of two components: (1) the smartwatch with custom-made FitSight watch application (app) to log the instant light illuminance levels the wearer is exposed to, and (2) a companion smartphone app that synchronizes the time outdoors recorded by the smartwatch to smartphone via Bluetooth communication. Smartwatch wear patterns and tracker-recorded daily light illuminance levels data were gathered over 7 days from 23 Singapore children (mean ± standard deviation age: 9.2 ± 1.4 years). Feedback about the tracker was obtained from 14 parents using a three-level rating scale: very poor/poor/good. Of the 14 parents, 93% rated the complete "FitSight fitness tracker" as good and 64% rated its wearability as good. While 61% of 23 children wore the watch on all study days (i.e., 0 nonwear days), 26% had 1 nonwear day, and 4.5% children each had 3, 4, and 5 nonwear days, respectively. On average, children spent approximately 1 hour in light levels greater than 1000 lux on weekdays and 1.3 hours on weekends (60 ± 46 vs. 79 ± 53 minutes, P = 0.19). Mean number of outdoor "spurts" (light illuminance levels >1000 lux) per day was 8 ± 3 spurts with spurt duration of 34 ± 32 minutes. The FitSight tracker with its novel features may motivate children to increase time outdoors and play an important role in supplementing community outdoor programs to prevent myopia. If the developed noninvasive, wearable, smartwatch-based fitness tracker, FitSight, promotes daytime outdoor activity among children, it will be beneficial in addressing the epidemic of myopia.

Genomic and environmental selection patterns in two distinct lettuce crop–wild hybrid crosses

PubMed Central

Hartman, Yorike; Uwimana, Brigitte; Hooftman, Danny A P; Schranz, Michael E; van de Wiel, Clemens C M; Smulders, Marinus J M; Visser, Richard G F; van Tienderen, Peter H

2013-01-01

Genomic selection patterns and hybrid performance influence the chance that crop (trans)genes can spread to wild relatives. We measured fitness(-related) traits in two different field environments employing two different crop–wild crosses of lettuce. We performed quantitative trait loci (QTL) analyses and estimated the fitness distribution of early- and late-generation hybrids. We detected consistent results across field sites and crosses for a fitness QTL at linkage group 7, where a selective advantage was conferred by the wild allele. Two fitness QTL were detected on linkage group 5 and 6, which were unique to one of the crop–wild crosses. Average hybrid fitness was lower than the fitness of the wild parent, but several hybrid lineages outperformed the wild parent, especially in a novel habitat for the wild type. In early-generation hybrids, this may partly be due to heterosis effects, whereas in late-generation hybrids transgressive segregation played a major role. The study of genomic selection patterns can identify crop genomic regions under negative selection across multiple environments and cultivar–wild crosses that might be applicable in transgene mitigation strategies. At the same time, results were cultivar-specific, so that a case-by-case environmental risk assessment is still necessary, decreasing its general applicability. PMID:23789025

Genomic and environmental selection patterns in two distinct lettuce crop-wild hybrid crosses.

PubMed

Hartman, Yorike; Uwimana, Brigitte; Hooftman, Danny A P; Schranz, Michael E; van de Wiel, Clemens C M; Smulders, Marinus J M; Visser, Richard G F; van Tienderen, Peter H

2013-06-01

Genomic selection patterns and hybrid performance influence the chance that crop (trans)genes can spread to wild relatives. We measured fitness(-related) traits in two different field environments employing two different crop-wild crosses of lettuce. We performed quantitative trait loci (QTL) analyses and estimated the fitness distribution of early- and late-generation hybrids. We detected consistent results across field sites and crosses for a fitness QTL at linkage group 7, where a selective advantage was conferred by the wild allele. Two fitness QTL were detected on linkage group 5 and 6, which were unique to one of the crop-wild crosses. Average hybrid fitness was lower than the fitness of the wild parent, but several hybrid lineages outperformed the wild parent, especially in a novel habitat for the wild type. In early-generation hybrids, this may partly be due to heterosis effects, whereas in late-generation hybrids transgressive segregation played a major role. The study of genomic selection patterns can identify crop genomic regions under negative selection across multiple environments and cultivar-wild crosses that might be applicable in transgene mitigation strategies. At the same time, results were cultivar-specific, so that a case-by-case environmental risk assessment is still necessary, decreasing its general applicability.

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.

Multiclassifier information fusion methods for microarray pattern recognition

NASA Astrophysics Data System (ADS)

Braun, Jerome J.; Glina, Yan; Judson, Nicholas; Herzig-Marx, Rachel

2004-04-01

This paper addresses automatic recognition of microarray patterns, a capability that could have a major significance for medical diagnostics, enabling development of diagnostic tools for automatic discrimination of specific diseases. The paper presents multiclassifier information fusion methods for microarray pattern recognition. The input space partitioning approach based on fitness measures that constitute an a-priori gauging of classification efficacy for each subspace is investigated. Methods for generation of fitness measures, generation of input subspaces and their use in the multiclassifier fusion architecture are presented. In particular, two-level quantification of fitness that accounts for the quality of each subspace as well as the quality of individual neighborhoods within the subspace is described. Individual-subspace classifiers are Support Vector Machine based. The decision fusion stage fuses the information from mulitple SVMs along with the multi-level fitness information. Final decision fusion stage techniques, including weighted fusion as well as Dempster-Shafer theory based fusion are investigated. It should be noted that while the above methods are discussed in the context of microarray pattern recognition, they are applicable to a broader range of discrimination problems, in particular to problems involving a large number of information sources irreducible to a low-dimensional feature space.

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.

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.

On the response of Y 3Al 5O 12: Ce (YAG: Ce) powder scintillating screens to medical imaging X-rays

NASA Astrophysics Data System (ADS)

Kandarakis, I.; Cavouras, D.; Sianoudis, I.; Nikolopoulos, D.; Episkopakis, A.; Linardatos, D.; Margetis, D.; Nirgianaki, E.; Roussou, M.; Melissaropoulos, P.; Kalivas, N.; Kalatzis, I.; Kourkoutas, K.; Dimitropoulos, N.; Louizi, A.; Nomicos, C.; Panayiotakis, G.

2005-02-01

The aim of this study was to examine Y 3Al 5O 12:Ce (also known as YAG:Ce) powder scintillator under X-ray imaging conditions. This material shows a very fast scintillation decay time and it has never been used in X-ray medical imaging. In the present study various scintillator layers (screens) with coating thickness ranging from 13 to 166 mg/cm 2 were prepared in our laboratory by sedimentation of Y 3Al 5O 12: Ce powder. Optical emission spectra and light emission efficiency (spectrum area over X-ray exposure) of the layers were measured under X-ray excitation using X-ray tube voltages (80-120 kVp) often employed in general medical radiography and fluoroscopy. Spectral compatibility with various optical photon detectors (photodiodes, photocathodes, charge coupled devices, films) and intrinsic conversion efficiency values were determined using emission spectrum data. In addition, parameters related to X-ray detection, energy absorption efficiency and K-fluorescence characteristic emission were calculated. A theoretical model describing radiation and light transfer through scattering media was used to fit experimental data. Intrinsic conversion efficiency (η≈0.03-0.05) and light attenuation coefficients (σ≈26.5 cm/g) were derived through this fitting. Y 3Al 5O 12:Ce showed peak emission in the wavelength range 530-550 nm. The light emission efficiency was found to be maximum for the 107 mg/cm 2 layer. Due to its "green" emission spectrum, Y 3Al 5O 12:Ce showed excellent compatibility (of the order of 0.9) with the sensitivity of many currently used photodetectors. Taking into account its very fast response Y 3Al 5O 12:Ce could be considered for application in X-ray imaging especially in various digital detectors.

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...

1D hetero-bimetallic regularly alternated 4f-3d coordination polymers based on N-oxide-4,4'-bipyridine (bipyMO) as a linker: photoluminescence and magnetic properties.

PubMed

Armelao, Lidia; Belli Dell'Amico, Daniela; Bottaro, Gregorio; Bellucci, Luca; Labella, Luca; Marchetti, Fabio; Mattei, Carlo Andrea; Mian, Federica; Pineider, Francesco; Poneti, Giordano; Samaritani, Simona

2018-06-13

Heterotopic divergent ligand N-oxide-4,4'-bipyridine (bipyMO) has been herein exploited for the preparation of hetero-bimetallic coordination polymers where Ln(hfac)3 and M(hfac)2 nodes regularly alternate (Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione), bipyMO being able to selectively use its two potential coordination sites to discriminate the metal ions. The synthesis of three coordination polymers, [Ln(hfac)3M(hfac)2(bipyMO)2]n (Ln = Eu, M = Zn, 1; Ln = Eu, M = Cu, 2, Ln = Dy, M = Co, 3), was carried out by reacting the appropriate [M(hfac)2(bipyMO)]n and [Ln(hfac)3] precursors in toluene in the presence of a given stoichiometric amount of bipyMO. The products were characterized by elemental analysis, X-ray powder diffraction, and FTIR spectroscopy. Single crystal X-ray diffraction studies carried out on 2 showed that it was formed by chains containing the hexa-coordinated 3d metal (Cu(hfac)2[N]2) and the octa-coordinated lanthanide (Eu(hfac)3[O]2) nodes, where [N] and [O] stand for the donor atom of the bridging divergent ligand. The X-ray powder diffraction patterns of the three compounds and the comparison of their cell constant values allowed establishing that the derivatives were isotypic. Photoluminescence (PL) studies on microcrystalline sample powders evidenced a bright red emission for 1 with an absolute PL quantum yield of 0.24. The sensitized emission of Eu3+ can be excited in a wide wavelength range, from UV to visible, up to ≈450 nm. Conversely, europium emissions are not detectable in 2 due to the presence of Cu(hfac)2(bipyMO) moieties whose strong absorption overlaps Eu3+ transitions. Magnetic measurements conducted on 3 revealed the presence of a weak ferromagnetic interaction below 2.1 K. An ac susceptibility study highlighted a slow relaxation of the magnetization of 3 with an applied static magnetic field of 0.1 T, which could be equally fitted with a Orbach-direct or a Raman-direct mechanism. No relaxation dynamics was detected without the application of a static magnetic field.

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

Regional Cultures and the Psychological Geography of Switzerland: Person–Environment–Fit in Personality Predicts Subjective Wellbeing

PubMed Central

Götz, Friedrich M.; Ebert, Tobias; Rentfrow, Peter J.

2018-01-01

The present study extended traditional nation-based research on person–culture–fit to the regional level. First, we examined the geographical distribution of Big Five personality traits in Switzerland. Across the 26 Swiss cantons, unique patterns were observed for all traits. For Extraversion and Neuroticism clear language divides emerged between the French- and Italian-speaking South-West vs. the German-speaking North-East. Second, multilevel modeling demonstrated that person–environment–fit in Big Five, composed of elevation (i.e., mean differences between individual profile and cantonal profile), scatter (differences in mean variances) and shape (Pearson correlations between individual and cantonal profiles across all traits; Furr, 2008, 2010), predicted the development of subjective wellbeing (i.e., life satisfaction, satisfaction with personal relationships, positive affect, negative affect) over a period of 4 years. Unexpectedly, while the effects of shape were in line with the person–environment–fit hypothesis (better fit predicted higher subjective wellbeing), the effects of scatter showed the opposite pattern, while null findings were observed for elevation. Across a series of robustness checks, the patterns for shape and elevation were consistently replicated. While that was mostly the case for scatter as well, the effects of scatter appeared to be somewhat less robust and more sensitive to the specific way fit was modeled when predicting certain outcomes (negative affect, positive affect). Distinguishing between supplementary and complementary fit may help to reconcile these findings and future research should explore whether and if so under which conditions these concepts may be applicable to the respective facets of person–culture–fit. PMID:29713299

Regional Cultures and the Psychological Geography of Switzerland: Person-Environment-Fit in Personality Predicts Subjective Wellbeing.

PubMed

Götz, Friedrich M; Ebert, Tobias; Rentfrow, Peter J

2018-01-01

The present study extended traditional nation-based research on person-culture-fit to the regional level. First, we examined the geographical distribution of Big Five personality traits in Switzerland. Across the 26 Swiss cantons, unique patterns were observed for all traits. For Extraversion and Neuroticism clear language divides emerged between the French- and Italian-speaking South-West vs. the German-speaking North-East. Second, multilevel modeling demonstrated that person-environment-fit in Big Five, composed of elevation (i.e., mean differences between individual profile and cantonal profile), scatter (differences in mean variances) and shape (Pearson correlations between individual and cantonal profiles across all traits; Furr, 2008, 2010), predicted the development of subjective wellbeing (i.e., life satisfaction, satisfaction with personal relationships, positive affect, negative affect) over a period of 4 years. Unexpectedly, while the effects of shape were in line with the person-environment-fit hypothesis (better fit predicted higher subjective wellbeing), the effects of scatter showed the opposite pattern, while null findings were observed for elevation. Across a series of robustness checks, the patterns for shape and elevation were consistently replicated. While that was mostly the case for scatter as well, the effects of scatter appeared to be somewhat less robust and more sensitive to the specific way fit was modeled when predicting certain outcomes (negative affect, positive affect). Distinguishing between supplementary and complementary fit may help to reconcile these findings and future research should explore whether and if so under which conditions these concepts may be applicable to the respective facets of person-culture-fit.

Ectoparasites and fitness of female Columbian ground squirrels

PubMed Central

Raveh, Shirley; Neuhaus, Peter; Dobson, F. Stephen

2015-01-01

Parasites play an important role in the evolution of host traits via natural selection, coevolution and sexually selected ornaments used in mate choice. These evolutionary scenarios assume fitness costs for hosts. To test this assumption, we conducted an ectoparasite removal experiment in free-living Columbian ground squirrels (Urocittelus columbianus) in four populations over three years. Adult females were randomly chosen to be either experimentally treated with anti-parasite treatments (spot-on solution and flea powder, N = 61) or a sham treatment (control, N = 44). We expected that experimental females would show better body condition, increased reproductive success and enhanced survival. Contrary to our expectations, body mass was not significantly different between treatments at mating, birth of litter or weaning of young. Further, neither number nor size of young at weaning differed significantly between the two treatments. Survival to the next spring for adult females and juveniles was not significantly different between experimental and control treatments. Finally, annual fitness was not affected by the treatments. We concluded that females and their offspring were able compensate for the presence of ectoparasites, suggesting little or no fitness costs of parasites for females in the different colonies and during the years of our experiments. PMID:25870399

Structural, vibrational, thermal and optical studies of organic single crystal: Benzotriazolium p-toluene sulfonate (BTPTS)

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

Kumar, R. Ramesh; Sathya, P.; Gopalakrishnan, R., E-mail: krgkrishnan@yahoo.com

Benzotriazolium p-toluene sulfonate (BTPTS) was grown by solution growth technique. The powder X-ray diffraction analysis was carried out to evaluate crystal system of the compound. LeBail Profile fitting analysis was performed to extract the individual peak intensities. FTIR spectrum analysis was recorded to study vibration frequencies of the prepared organic salt. Thermal studies were carried out using TG-DSC analysis. Optical absorption and energy band gap of the title compound was evaluated by UV-Vis spectral study.

The Effect of Muzzle Jet Asymmetry on Projectile Motion

DTIC Science & Technology

1975-01-01

fixture was designed to provide invariant mechanical support to the gun tube while allowing control of the symmetry of the muzzle gar flow field...Figure 4. A 2S4mm diameter by 12.7mm thick (non-metric dimensions: 10 in x 1/2 in) aluminum base plate is press fit onto the muzzle of a 6.71mm...indicated by the opaque regions of concentrated powder particles. The muzzle flow at a considerably later time, Figure 1, shows the projectile to be

Analysis of Crystallization Kinetics

NASA Technical Reports Server (NTRS)

Kelton, Kenneth F.

1997-01-01

A realistic computer model for polymorphic crystallization (i.e., initial and final phases with identical compositions), which includes time-dependent nucleation and cluster-size-dependent growth rates, is developed and tested by fits to experimental data. Model calculations are used to assess the validity of two of the more common approaches for the analysis of crystallization data. The effects of particle size on transformation kinetics, important for the crystallization of many systems of limited dimension including thin films, fine powders, and nanoparticles, are examined.

Periodic Pattern of Genetic and Fitness Diversity during Evolution of an Artificial Cell-Like System.

PubMed

Ichihashi, Norikazu; Aita, Takuyo; Motooka, Daisuke; Nakamura, Shota; Yomo, Tetsuya

2015-12-01

Genetic and phenotypic diversity are the basis of evolution. Despite their importance, however, little is known about how they change over the course of evolution. In this study, we analyzed the dynamics of the adaptive evolution of a simple evolvable artificial cell-like system using single-molecule real-time sequencing technology that reads an entire single artificial genome. We found that the genomic RNA population increases in fitness intermittently, correlating with a periodic pattern of genetic and fitness diversity produced by repeated diversification and domination. In the diversification phase, a genomic RNA population spreads within a genetic space by accumulating mutations until mutants with higher fitness are generated, resulting in an increase in fitness diversity. In the domination phase, the mutants with higher fitness dominate, decreasing both the fitness and genetic diversity. This study reveals the dynamic nature of genetic and fitness diversity during adaptive evolution and demonstrates the utility of a simplified artificial cell-like system to study evolution at an unprecedented resolution. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

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.

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.

New database for improving virtual system “body-dress”

NASA Astrophysics Data System (ADS)

Yan, J. Q.; Zhang, S. C.; Kuzmichev, V. E.; Adolphe, D. C.

2017-10-01

The aim of this exploration is to develop a new database of solid algorithms and relations between the dress fit and the fabric mechanical properties, the pattern block construction for improving the reality of virtual system “body-dress”. In virtual simulation, the system “body-clothing” sometimes shown distinct results with reality, especially when important changes in pattern block and fabrics were involved. In this research, to enhance the simulation process, diverse fit parameters were proposed: bottom height of dress, angle of front center contours, air volume and its distribution between dress and dummy. Measurements were done and optimized by ruler, camera, 3D body scanner image processing software and 3D modeling software. In the meantime, pattern block indexes were measured and fabric properties were tested by KES. Finally, the correlation and linear regression equations between indexes of fabric properties, pattern blocks and fit parameters were investigated. In this manner, new database could be extended in programming modules of virtual design for more realistic results.

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.

A new metric of inclusive fitness predicts the human mortality profile.

PubMed

Newman, Saul J; Easteal, Simon

2015-01-01

Biological species have evolved characteristic patterns of age-specific mortality across their life spans. If these mortality profiles are shaped by natural selection they should reflect underlying variation in the fitness effect of mortality with age. Direct fitness models, however, do not accurately predict the mortality profiles of many species. For several species, including humans, mortality rates vary considerably before and after reproductive ages, during life-stages when no variation in direct fitness is possible. Variation in mortality rates at these ages may reflect indirect effects of natural selection acting through kin. To test this possibility we developed a new two-variable measure of inclusive fitness, which we term the extended genomic output or EGO. Using EGO, we estimate the inclusive fitness effect of mortality at different ages in a small hunter-gatherer population with a typical human mortality profile. EGO in this population predicts 90% of the variation in age-specific mortality. This result represents the first empirical measurement of inclusive fitness of a trait in any species. It shows that the pattern of human survival can largely be explained by variation in the inclusive fitness cost of mortality at different ages. More generally, our approach can be used to estimate the inclusive fitness of any trait or genotype from population data on birth dates and relatedness.

Method of modelling the compaction behaviour of cylindrical pharmaceutical tablets.

PubMed

Ahmat, Norhayati; Ugail, Hassan; Castro, Gabriela González

2011-02-28

The mechanisms involved for compaction of pharmaceutical powders have become a crucial step in the development cycle for robust tablet design with required properties. Compressibility of pharmaceutical materials is measured by a force-displacement relationship which is commonly analysed using a well known method, the Heckel model. This model requires the true density and compacted powder mass value to determine the powder mean yield pressure. In this paper, we present a technique for shape modelling of pharmaceutical tablets based on the use of partial differential equations (PDEs). This work also presents an extended formulation of the PDE method to a higher dimensional space by increasing the number of parameters responsible for describing the surface in order to generate a solid tablet. Furthermore, the volume and the surface area of the parametric cylindrical tablet have been estimated numerically. Finally, the solution of the axisymmetric boundary value problem for a finite cylinder subject to a uniform axial load has been utilised in order to model the displacement components of a compressed PDE-based representation of a tablet. The Heckel plot obtained from the developed model shows that the model is capable of predicting the compaction behaviour of pharmaceutical materials since it fits the experimental data accurately. Copyright © 2010 Elsevier B.V. All rights reserved.

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).

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

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

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.

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.

Optimal time following fluorescein instillation to evaluate rigid gas permeable contact lens fit.

PubMed

Wolffsohn, James S; Tharoo, Ali; Lakhlani, Nikita

2015-04-01

To examine the optimum time at which fluorescein patterns of gas permeable lenses (GPs) should be evaluated. Aligned, 0.2mm steep and 0.2mm flat GPs were fitted to 17 patients (aged 20.6 ± 1.1 years, 10 male). Fluorescein was applied to their upper temporal bulbar conjunctiva with a moistened fluorescein strip. Digital slit lamp images (CSO, Italy) at 10× magnification of the fluorescein pattern viewed with blue light through a yellow filter were captured every 15s. Fluorescein intensity in central, mid peripheral and edge regions of the superior, inferior, temporal and nasal quadrants of the lens were graded subjectively using a +2 to -2 scale and using ImageJ software on the simultaneously captured images. Subjectively graded and objectively image analysed fluorescein intensity changed with time (p < 0.001), lens region (centre, mid-periphery and edge: p < 0.05) and there was interaction between lens region with lens fit (p < 0.001). For edge band width, there was a significant effect of time (F = 118.503, p < 0.001) and lens fit (F = 5.1249, p = 0.012). The expected alignment, flat and steep fitting patterns could be seen from approximately after 30 to 180 s subjectively and 15 to 105 s in captured images. Although the stability of fluorescein intensity can start to decline in as little as 45 s post fluorescein instillation, the diagnostic pattern of alignment, steep or flat fit is seen in each meridian by subjective observation from about 30s to 3 min indicating this is the most appropriate time window to evaluate GP lenses in clinical practice. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Impact of Striped-Squirrel Nectar-Robbing Behaviour on Gender Fitness in Alpinia roxburghii Sweet (Zingiberaceae)

PubMed Central

Deng, Xiaobao; Mohandass, Dharmalingam; Katabuchi, Masatoshi; Hughes, Alice C.; Roubik, David W.

2015-01-01

Nectar-robbing has the potential to strongly affect male and female reproductive fitness of plants. One example of nectar theft is that shown by striped-squirrels (Tamiops swinhoei) on a number of ginger species, including Alpinia roxburghii and A. kwangsiensis (Zingiberaceae). In this study, we used a fluorescent dye as a pollen analogue, and measured fruit and seed output, to test the effect of squirrel nectar-robbing on A. roxburghii reproductive fitness. Pollen transfer between robbed and unrobbed flowers was assessed by comparing 60 randomly established plots containing robbed and unrobbed flowers. The frequency of squirrel robbing visits and broken styles were recorded from a number of flowers for five consecutive days. Two bee species (Bombus eximius and Apis cerana), were the primary pollinators, and their visitation frequency was recorded for six consecutive days. The results showed that fluorescent powder from unrobbed flowers was dispersed further, and to a greater number of flowers than that placed on robbed flowers. Additionally, robbing flowers caused significant damage to reproductive organs, resulting in lower fruit and seed sets in robbed than in unrobbed flowers and influencing both male and female fitness. The frequency of the primary pollinator visits (B. eximius) was significantly higher for unrobbed plants than for robbed plants. The present study clearly shows the negative impact of squirrel robbing on A. roxburghii male reproductive fitness and neutral impact on female reproductive fitness. PMID:26689684

Fitness trade-offs of group formation and movement by Thomson's gazelles in the Serengeti ecosystem.

PubMed

Fryxell, John M; Berdahl, Andrew M

2018-05-19

Collective behaviours contributing to patterns of group formation and coordinated movement are common across many ecosystems and taxa. Their ubiquity is presumably due to altering interactions between individuals and their predators, resources and physical environment in ways that enhance individual fitness. On the other hand, fitness costs are also often associated with group formation. Modifications to these interactions have the potential to dramatically impact population-level processes, such as trophic interactions or patterns of space use in relation to abiotic environmental variation. In a wide variety of empirical systems and models, collective behaviour has been shown to enhance access to ephemeral patches of resources, reduce the risk of predation and reduce vulnerability to environmental fluctuation. Evolution of collective behaviour should accordingly depend on the advantages of collective behaviour weighed against the costs experienced at the individual level. As an illustrative case study, we consider the potential trade-offs on Malthusian fitness associated with patterns of group formation and movement by migratory Thomson's gazelles in the Serengeti ecosystem.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Authors.

Degradation of metaldehyde in water by nanoparticle catalysts and powdered activated carbon.

PubMed

Li, Zhuojun; Kim, Jong Kyu; Chaudhari, Vrushali; Mayadevi, Suseeladevi; Campos, Luiza C

2017-07-01

Metaldehyde, an organic pesticide widely used in the UK, has been detected in drinking water in the UK with a low concentration (<1 μg L -1 ) which is still above the European and UK standard requirements. This paper investigates the efficiency of four materials: powdered activated carbon (PAC) and carbon-doped titanium dioxide nanocatalyst with different concentrations of carbon (C-1.5, C-40, and C-80) for metaldehyde removal from aqueous solutions by adsorption and oxidation via photocatalysis. PAC was found to be the most effective material which showed almost over 90% removal. Adsorption data were well fitted to the Langmuir isotherm model, giving a q m (maximum/saturation adsorption capacity) value of 32.258 mg g -1 and a K L (Langmuir constant) value of 2.013 L mg -1 . In terms of kinetic study, adsorption of metaldehyde by PAC fitted well with a pseudo-second-order equation, giving the adsorption rate constant k 2 value of 0.023 g mg -1  min -1 , implying rapid adsorption. The nanocatalysts were much less effective in oxidising metaldehyde than PAC with the same metaldehyde concentration and 0.2 g L -1 loading concentration of materials under UV light; the maximum removal achieved by carbon-doped titanium dioxide (C-1.5) nanocatalyst was around 15% for a 7.5 ppm metaldehyde solution. Graphical abstract ᅟ.

Comparison on the Surface Structure Properties along with Fe(II) and Mn(II) Removal Characteristics of Rice Husk Ash, Inactive Saccharomyces cerevisiae Powder, and Rice Husk

PubMed Central

Jiang, Zhao; Cao, Bo; Su, Guangxia; Lu, Yan; Zhao, Jiaying; Shan, Dexin; Zhang, Xiuyuan; Wang, Ziyi

2016-01-01

This study selected solid wastes, such as rice husk ash (RHA), inactive Saccharomyces cerevisiae powder (ISP), and rice husk (RH), as the potential adsorbents for the removal of Fe(II) and Mn(II) in aqueous solution. The structural characteristics, functional groups, and elemental compositions were determined by scanning electron microscope (SEM) and Fourier translation infrared spectrum (FT-IR) analyses, respectively. Then the influence on the Fe(II) and Mn(II) removing efficiency by the factors, such as pH, adsorbent dosage, initial Fe(II) and Mn(II) concentration, and contact time, was investigated by the static batch test. The adsorption isotherm study results show that Langmuir equation can better fit the Fe(II) and Mn(II) adsorption process by the three adsorbents. The maximum adsorption amounts for Fe(II) were 6.211 mg/g, 4.464 mg/g, and 4.049 mg/g by RHA, ISP, and RH and for Mn(II) were 3.016 mg/g, 2.229 mg/g, and 1.889 mg/g, respectively. The adsorption kinetics results show that the pseudo-second-order kinetic model can better fit the Fe(II) and Mn(II) adsorption process. D-R model and thermodynamic parameters hint that the adsorption processes of Fe(II) and Mn(II) on the three adsorbents took place physically and the processes were feasible, spontaneous, and exothermic. PMID:28042571

Effect of ultrasonic treatment and temperature on nanocrystalline TiO 2

NASA Astrophysics Data System (ADS)

Kim, D. H.; Ryu, H. W.; Moon, J. H.; Kim, J.

Nanocrystalline TiO 2 particles were precipitated from the ethanol solution of titanium isopropoxide (Ti(O- iPr) 4) and H 2O 2 by refluxing at 80 °C for 48 h. The obtained particles were filtered and dried at 100 °C for 12 h. The dried powder itself, the sample with heating at 400 °C, and the sample with ultrasonically treating were prepared to investigate the effects of post treatments on materials characteristics and electrochemical properties of nanocrystalline TiO 2. The X-ray diffraction patterns of all of the samples were fitted well to the anatase phase. The field emission-TEM image of as-prepared sample shows a uniform spherical morphology with 5 nm particle size and the sample heated at 400 °C shows slightly increased particle size of about 10 nm while maintaining spherical shape. The sample treated with ultrasonic for 5 h or more at room temperature shows high aspect ratio particle shape with an average diameter of 5 nm and a length of 20 nm. According to the results of the electrochemical testing, as-prepared sample, the sample heated at 400 °C for 3 h, and the sample treated with ultrasonic show initial capacities of 270, 310 and 340 mAh g -1, respectively.

Removal of ammonium and heavy metals by cost-effective zeolite synthesized from waste quartz sand and calcium fluoride sludge.

PubMed

Zhang, Qian; Lin, Bing; Hong, Junming; Chang, Chang-Tang

2017-02-01

This study focuses on the effectiveness of zeolite (10% CF-Z [0.5]) hydrothermally synthesized from waste quartz sand and calcium fluoride (CF) for ammonium ion and heavy metal removal. Zeolite was characterized through powder X-ray diffraction, Fourier-transform infrared spectroscopy, micromeritics N 2 adsorption/desorption analysis, and field emission scanning electron microscopy. The effects of CF addition, Si/Al ratio, initial ammonium concentration, solution pH, and temperature on the adsorption of ammonium on 10% CF-Z (0.5) were further examined. Results showed that 10% CF-Z (0.5) was a single-phase zeolite A with cubic-shaped crystals and 10% CF-Z (0.5) efficiently adsorbs ammonium and heavy metals. For instance, 91% ammonium (10 mg L -1 ) and 93% lead (10 mg L -1 ) are removed. The adsorption isotherm, kinetics, and thermodynamics of ammonium adsorption on 10% CF-Z (0.5) were also theoretically analyzed. The adsorption isotherm of ammonium and lead on 10% CF-Z (0.5) in single systems indicated that Freundlich model provides the best fit for the equilibrium data, whereas pseudo-second-order model best describes the adsorption kinetics. The adsorption degree of ions on 10% CF-Z (0.5) in mixed systems exhibits the following pattern: lead > ammonium > cadmium > chromium.

"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.

Outlier Detection in High-Stakes Certification Testing. Research Report.

ERIC Educational Resources Information Center

Meijer, Rob R.

Recent developments of person-fit analysis in computerized adaptive testing (CAT) are discussed. Methods from statistical process control are presented that have been proposed to classify an item score pattern as fitting or misfitting the underlying item response theory (IRT) model in a CAT. Most person-fit research in CAT is restricted to…

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...

“Fit” inside the Work-Family Black Box: An Ecology of the Life Course, Cycles of Control Reframing1

PubMed Central

Moen, Phyllis; Kelly, Erin; Huang, Reiping

2009-01-01

Scholars have not fully theorized the multifaceted, interdependent dimensions within the work-family “black box.” Taking an ecology of the life course approach, we theorize common work-family and adequacy constructs as capturing different components of employees' cognitive appraisals of fit between their demands and resources at the interface between home and work. Employees' appraisals of their work-family linkages and of their relative resource adequacy are not made independently but, rather, co-occur as identifiable constellations of fit. The life course approach hypothesizes that shifts in objective demands/ resources at work and at home over the life course result in employees experiencing cycles of control, that is, corresponding shifts in their cognitive assessments of fit. We further theorize patterned appraisals of fit are key mediators between objective work-family conditions and employees' health, well-being and strategic adaptations. As a case example, we examine whether employees' assessments on ten dimensions cluster together as patterned fit constellations, using data from a middle-class sample of 753 employees working at Best Buy's corporate headquarters. We find no single linear construct of fit that captures the complexity within the work-family black box. Instead, respondents experience six distinctive constellations of fit: one optimal, two poor, and three moderate fit constellations. PMID:19809532

Nonlinear Structured Growth Mixture Models in Mplus and OpenMx

PubMed Central

Grimm, Kevin J.; Ram, Nilam; Estabrook, Ryne

2014-01-01

Growth mixture models (GMMs; Muthén & Muthén, 2000; Muthén & Shedden, 1999) are a combination of latent curve models (LCMs) and finite mixture models to examine the existence of latent classes that follow distinct developmental patterns. GMMs are often fit with linear, latent basis, multiphase, or polynomial change models because of their common use, flexibility in modeling many types of change patterns, the availability of statistical programs to fit such models, and the ease of programming. In this paper, we present additional ways of modeling nonlinear change patterns with GMMs. Specifically, we show how LCMs that follow specific nonlinear functions can be extended to examine the presence of multiple latent classes using the Mplus and OpenMx computer programs. These models are fit to longitudinal reading data from the Early Childhood Longitudinal Study-Kindergarten Cohort to illustrate their use. PMID:25419006

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.

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.

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.

Iron oxide impregnated Morus alba L. fruit peel for biosorption of Co(II): biosorption properties and mechanism.

PubMed

Koduru, Janardhan Reddy; Chang, Yoon-Young; Yang, Jae-Kyu; Kim, Im-Soon

2013-01-01

Biosorption is an ecofriendly wastewater treatment technique with high efficiency and low operating cost involving simple process for the removal of heavy metal ions from aqueous solution. In the present investigation, Morus alba L. fruit peel powder (MAFP) and iron oxide impregnated Morus alba L. fruit peel powder (IO-MAFP) were prepared and used for treating Co(II) contaminated aqueous solutions. Further the materials were characterized by using FTIR and SEM-EDX analysis. From FT-IR analysis it was found that hydroxyl, methoxy, and carbonyl groups are responsible for Co(II) biosorption. The kinetic data obtained for both biosorbents was well fitted with pseudo-second-order kinetic model. The equilibrium data was in tune with the Langmuir and Freundlich isotherm models. The thermodynamic studies were also carried and it was observed that sorption process was endothermic at 298-328 K. These studies demonstrated that both biosorbents were promising, efficient, economic, and biodegradable sorbents.

Jute stick powder as a potential biomass for the removal of congo red and rhodamine B from their aqueous solution.

PubMed

Panda, Gopal C; Das, Sujoy K; Guha, Arun K

2009-05-15

Jute stick powder (JSP) has been found to be a promising material for adsorptive removal of congo red (C.I. 22120) and rhodamine B (C.I. 45170) from aqueous solutions. Physico-chemical parameters like dye concentration, solution pH, temperature and contact time have been varied to study the adsorption phenomenon. Favorable adsorption occurs at around pH 7.0 whereas temperature has no significant effect on adsorption of both the dyes. The maximum adsorption capacity has been calculated to be 35.7 and 87.7mg/g of the biomass for congo red and rhodamine B, respectively. The adsorption process is in conformity with Freundlich and Langmuir isotherms for rhodamine B whereas congo red adsorption fits well to Langmuir isotherm only. In both the cases, adsorption occurs very fast initially and attains equilibrium within 60min. Kinetic results suggest the intra-particle diffusion of dyes as rate limiting step.

Effective optical constants of anisotropic materials

NASA Technical Reports Server (NTRS)

Aronson, J. R.; Emslie, A. G.

1980-01-01

The applicability of a technique for determining the optical constants of soil or aerosol components on the basis of measurements of the reflectance or transmittance of inhomogeneous samples of component material is investigated. Optical constants for a sample of very pure quartzite were obtained by a specular reflection technique and line parameters were calculated by classical dispersion theory. Predictions of the reflectance of powdered quartz were then derived from optical constants measured for the anisotropic quartz and for pure quartz crystals, and compared with experimental measurements. The calculated spectra are found to resemble each other moderately well in shape, however the reflectance level calculated from the psuedo-optical constants (quartzite) is consistently below that calculated from quartz values. The spectrum calculated from the quartz optical constants is also shown to represent the experimental nonrestrahlen features more accurately. It is thus concluded that although optical constants derived from inhomogeneous materials may represent the spectral features of a powdered sample qualitatively a quantitative fit to observed data is not likely.

Ab initio random structure searching of organic molecular solids: assessment and validation against experimental data.

PubMed

Zilka, Miri; Dudenko, Dmytro V; Hughes, Colan E; Williams, P Andrew; Sturniolo, Simone; Franks, W Trent; Pickard, Chris J; Yates, Jonathan R; Harris, Kenneth D M; Brown, Steven P

2017-10-04

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.

Chromium (Ⅵ) removal from aqueous solutions through powdered activated carbon countercurrent two-stage adsorption.

PubMed

Wang, Wenqiang

2018-01-01

To exploit the adsorption capacity of commercial powdered activated carbon (PAC) and to improve the efficiency of Cr(VI) removal from aqueous solutions, the adsorption of Cr(VI) by commercial PAC and the countercurrent two-stage adsorption (CTA) process was investigated. Different adsorption kinetics models and isotherms were compared, and the pseudo-second-order model and the Langmuir and Freundlich models fit the experimental data well. The Cr(VI) removal efficiency was >80% and was improved by 37% through the CTA process compared with the conventional single-stage adsorption process when the initial Cr(VI) concentration was 50 mg/L with a PAC dose of 1.250 g/L and a pH of 3. A calculation method for calculating the effluent Cr(VI) concentration and the PAC dose was developed for the CTA process, and the validity of the method was confirmed by a deviation of <5%. Copyright © 2017. Published by Elsevier Ltd.

Characterizations of strontium(II) and barium(II) adsorption from aqueous solutions using dolomite powder.

PubMed

Ghaemi, Ahad; Torab-Mostaedi, Meisam; Ghannadi-Maragheh, Mohammad

2011-06-15

In this research, adsorption technique was applied for strontium and barium removal from aqueous solution using dolomite powder. The process has been investigated as a function of pH, contact time, temperature and adsorbate concentration. The experimental data was analyzed using equilibrium isotherm, kinetic and thermodynamic models. The isotherm data was well described by Langmuir isotherm model. The maximum adsorption capacity was found to be 1.172 and 3.958 mg/g for Sr(II) and Ba(II) from the Langmuir isotherm model at 293 K, respectively. The kinetic data was tested using first and pseudo-second order models. The results indicated that adsorption fitted well with the pseudo-second order kinetic model. The thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were also determined using the equilibrium constant value obtained at different temperatures. The results showed that the adsorption for both ions was feasible and exothermic. Copyright © 2011 Elsevier B.V. All rights reserved.

Iron Oxide Impregnated Morus alba L. Fruit Peel for Biosorption of Co(II): Biosorption Properties and Mechanism

PubMed Central

Koduru, Janardhan Reddy; Chang, Yoon-Young; Yang, Jae-Kyu; Kim, Im-Soon

2013-01-01

Biosorption is an ecofriendly wastewater treatment technique with high efficiency and low operating cost involving simple process for the removal of heavy metal ions from aqueous solution. In the present investigation, Morus alba L. fruit peel powder (MAFP) and iron oxide impregnated Morus alba L. fruit peel powder (IO-MAFP) were prepared and used for treating Co(II) contaminated aqueous solutions. Further the materials were characterized by using FTIR and SEM-EDX analysis. From FT-IR analysis it was found that hydroxyl, methoxy, and carbonyl groups are responsible for Co(II) biosorption. The kinetic data obtained for both biosorbents was well fitted with pseudo-second-order kinetic model. The equilibrium data was in tune with the Langmuir and Freundlich isotherm models. The thermodynamic studies were also carried and it was observed that sorption process was endothermic at 298–328 K. These studies demonstrated that both biosorbents were promising, efficient, economic, and biodegradable sorbents. PMID:24324384

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

Von Dreele, Robert

One of the goals in developing GSAS-II was to expand from the capabilities of the original General Structure Analysis System (GSAS) which largely encompassed just structure refinement and post refinement analysis. GSAS-II has been written almost entirely in Python loaded with graphics, GUI and mathematical packages (matplotlib, pyOpenGL, wxpython, numpy and scipy). Thus, GSAS-II has a fully developed modern GUI as well as extensive graphical display of data and results. However, the structure and operation of Python has required new approaches to many of the algorithms used in crystal structure analysis. The extensions beyond GSAS include image calibration/integration as wellmore » as peak fitting and unit cell indexing for powder data which are precursors for structure solution. Structure solution within GSAS-II begins with either Pawley or LeBail extracted structure factors from powder data or those measured in a single crystal experiment. Both charge flipping and Monte Carlo-Simulated Annealing techniques are available; the former can be applied to (3+1) incommensurate structures as well as conventional 3D structures.« less

Singularities in the lineshape of a second-order perturbed quadrupolar nucleus and their use in data fitting.

PubMed

Field, Timothy R; Bain, Alex D

2014-01-01

Even for large quadrupolar interactions, the powder spectrum of the central transition for a half-integral spin is relatively narrow, because it is unperturbed to first order. However, the second-order perturbation is still orientation dependent, so it generates a characteristic lineshape. This lineshape has both finite step discontinuities and singularities where the spectrum is infinite, in theory. The relative positions of these features are well-known and they play an important role in fitting experimental data. However, there has been relatively little discussion of how high the steps are, so we present explicit formulae for these heights. This gives a full characterization of the features in this lineshape which can lead to an analysis of the spectrum without the usual laborious powder average. The transition frequency, as a function of the orientation angles, shows critical points: maxima, minima and saddle points. The maxima and minima correspond to the step discontinuities and the saddle points generate the singularities. Near a maximum, the contours are ellipses, whose dimensions are determined by the second derivatives of the frequency with respect to the polar and azimuthal angles. The density of points is smooth as the contour levels move up and down, but then drops to zero when a maximum is passed, giving a step. The height of the step is determined by the Hessian matrix-the matrix of all partial second derivatives. The points near the poles and the saddle points require a more detailed analysis, but this can still be done analytically. The resulting formulae are then compared to numerical simulations of the lineshape. We expand this calculation to include a relatively simple case where there is chemical shielding anisotropy and use this to fit experimental (139)La spectra of La2O3. Copyright © 2014 Elsevier Inc. All rights reserved.

Spherical combustion clouds in explosions

NASA Astrophysics Data System (ADS)

Kuhl, A. L.; Bell, J. B.; Beckner, V. E.; Balakrishnan, K.; Aspden, A. J.

2013-05-01

This study explores the properties of spherical combustion clouds in explosions. Two cases are investigated: (1) detonation of a TNT charge and combustion of its detonation products with air, and (2) shock dispersion of aluminum powder and its combustion with air. The evolution of the blast wave and ensuing combustion cloud dynamics are studied via numerical simulations with our adaptive mesh refinement combustion code. The code solves the multi-phase conservation laws for a dilute heterogeneous continuum as formulated by Nigmatulin. Single-phase combustion (e.g., TNT with air) is modeled in the fast-chemistry limit. Two-phase combustion (e.g., Al powder with air) uses an induction time model based on Arrhenius fits to Boiko's shock tube data, along with an ignition temperature criterion based on fits to Gurevich's data, and an ignition probability model that accounts for multi-particle effects on cloud ignition. Equations of state are based on polynomial fits to thermodynamic calculations with the Cheetah code, assuming frozen reactants and equilibrium products. Adaptive mesh refinement is used to resolve thin reaction zones and capture the energy-bearing scales of turbulence on the computational mesh (ILES approach). Taking advantage of the symmetry of the problem, azimuthal averaging was used to extract the mean and rms fluctuations from the numerical solution, including: thermodynamic profiles, kinematic profiles, and reaction-zone profiles across the combustion cloud. Fuel consumption was limited to ˜ 60-70 %, due to the limited amount of air a spherical combustion cloud can entrain before the turbulent velocity field decays away. Turbulent kinetic energy spectra of the solution were found to have both rotational and dilatational components, due to compressibility effects. The dilatational component was typically about 1 % of the rotational component; both seemed to preserve their spectra as they decayed. Kinetic energy of the blast wave decayed due to the pressure field. Turbulent kinetic energy of the combustion cloud decayed due to enstrophy overline{ω 2} and dilatation overline{Δ 2}.

Western and Mediterranean Dietary Patterns and Physical Activity and Fitness among Spanish Older Adults.

PubMed

Bibiloni, Maria Del Mar; Julibert, Alicia; Argelich, Emma; Aparicio-Ugarriza, Raquel; Palacios, Gonzalo; Pons, Antoni; Gonzalez-Gross, Marcela; Tur, Josep A

2017-07-06

Objectives: To assess prevailing food patterns, and its association with physical activity and fitness among Spanish older adults. Methods: Cross-sectional study in Spain, collecting data from a sample ( n = 380; 54% female) aged 55-80 years (men) and 60-80 years (women) with no previously documented cardiovascular disease. Body weight, body fat and waist circumference were assessed. Physical activity performed was measured using the Minnesota Leisure-time Physical Activity Questionnaire (LTPA). Physical fitness was assessed using a validated physical fitness test battery. Food consumption was assessed by a validated semi-quantitative food-frequency questionnaire. Factor analysis identified two major dietary food patterns: "Western" (WDP) and "Mediterranean" (MDP) dietary patterns. Results: Participants in MDP's fourth quartile were classified in the second (men) and third (men and women) tertile of LTPA. After adjusting for age, body fat, waist-to-height ratio, and METs, in both sexes, a negative significant association was found between 30-s Chair stand and 6-min walking test, a positive significant association was found between 30-m Gait speed and 8-foot Time Up-and-Go (except in men) tests with WDP. The 30-m Gait speed test was negatively associated with MDP in men. Conclusions: MDP is associated with more time spent on LTPA, and this association was independent of body composition and a fast gait speed in men. WDP is associated with slower gait speed and lower body strength, agility and aerobic endurance. MDP has protective effect on healthy physical fitness, and WDP may be a contributor to frailty.

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°.

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.

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.

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

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.

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.

Environmental Factors Can Influence Mitochondrial Inheritance in the Saccharomyces Yeast Hybrids.

PubMed

Hsu, Yu-Yi; Chou, Jui-Yu

2017-01-01

Mitochondria play a critical role in the generation of metabolic energy and are crucial for eukaryotic cell survival and proliferation. In most sexual eukaryotes, mitochondrial DNA (mtDNA) is inherited from only one parent in non-Mendelian inheritance in contrast to the inheritance of nuclear DNA. The model organism Saccharomyces cerevisiae is commonly used to study mitochondrial biology. It has two mating types: MATa and MATα. Previous studies have suggested that the mtDNA inheritance patterns in hybrid diploid cells depend on the genetic background of parental strains. However, the underlying mechanisms remain unclear. To elucidate the mechanisms, we examined the effects of environmental factors on the mtDNA inheritance patterns in hybrids obtained by crossing S. cerevisiae with its close relative S. paradoxus. The results demonstrated that environmental factors can influence mtDNA transmission in hybrid diploids, and that the inheritance patterns are strain dependent. The fitness competition assay results showed that the fitness differences can explain the mtDNA inheritance patterns under specific conditions. However, in this study, we found that fitness differences cannot fully be explained by mitochondrial activity in hybrids under stress conditions.

Thermodynamic Model of Aluminum Combustion in SDF Explosions

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

Kuhl, . L

2006-06-19

Thermodynamic states encountered during combustion of Aluminum powder in Shock-Dispersed-Fuel (SDF) explosions were analyzed with the Cheetah code. Results are displayed in the Le Chatelier diagram: the locus of states of specific internal energy versus temperature. Accuracy of the results was confirmed by comparing the fuel and products curves with the heats of detonation and combustion, and species composition as measured in bomb calorimeter experiments. Results were fit with analytic functions u = f(T) suitable for specifying the thermodynamic properties required for gas-dynamic models of combustion in explosions.

X-ray diffraction study of elemental thulium to 86 GPa

NASA Astrophysics Data System (ADS)

Pravica, Michael; Romano, Edward; Quine, Zachary; Pravica, Walter

2006-03-01

We have studied the structures and equation of state of elemental thulium up to 86 GPa in a diamond anvil cell using angular-dispersive x-ray powder diffraction methods at the Advanced Photon Source. This is part of a study of phase transitions in the lanthanide-series metals using cyclohexane as a quasi-hydrostatic medium. We present evidence of a series of phase transitions that appear to follow the anticipated hcp ->Sm-type -> dhcp -> distorted fcc sequence of transitions and show the equation of state derived from the x-ray fit data.

Person-Fit Statistics for Joint Models for Accuracy and Speed

ERIC Educational Resources Information Center

Fox, Jean-Paul; Marianti, Sukaesi

2017-01-01

Response accuracy and response time data can be analyzed with a joint model to measure ability and speed of working, while accounting for relationships between item and person characteristics. In this study, person-fit statistics are proposed for joint models to detect aberrant response accuracy and/or response time patterns. The person-fit tests…

How to Compare Parametric and Nonparametric Person-Fit Statistics Using Real Data

ERIC Educational Resources Information Center

Sinharay, Sandip

2017-01-01

Person-fit assessment (PFA) is concerned with uncovering atypical test performance as reflected in the pattern of scores on individual items on a test. Existing person-fit statistics (PFSs) include both parametric and nonparametric statistics. Comparison of PFSs has been a popular research topic in PFA, but almost all comparisons have employed…

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.

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

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

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.

Comparison the Marginal and Internal Fit of Metal Copings Cast from Wax Patterns Fabricated by CAD/CAM and Conventional Wax up Techniques.

PubMed

Vojdani, M; Torabi, K; Farjood, E; Khaledi, Aar

2013-09-01

Metal-ceramic crowns are most commonly used as the complete coverage restorations in clinical daily use. Disadvantages of conventional hand-made wax-patterns introduce some alternative ways by means of CAD/CAM technologies. This study compares the marginal and internal fit of copings cast from CAD/CAM and conventional fabricated wax-patterns. Twenty-four standardized brass dies were prepared and randomly divided into 2 groups according to the wax-patterns fabrication method (CAD/CAM technique and conventional method) (n=12). All the wax-patterns were fabricated in a standard fashion by means of contour, thickness and internal relief (M1-M12: representative of CAD/CAM group, C1-C12: representative of conventional group). CAD/CAM milling machine (Cori TEC 340i; imes-icore GmbH, Eiterfeld, Germany) was used to fabricate the CAD/CAM group wax-patterns. The copings cast from 24 wax-patterns were cemented to the corresponding dies. For all the coping-die assemblies cross-sectional technique was used to evaluate the marginal and internal fit at 15 points. The Student's t- test was used for statistical analysis (α=0.05). The overall mean (SD) for absolute marginal discrepancy (AMD) was 254.46 (25.10) um for CAD/CAM group and 88.08(10.67) um for conventional group (control). The overall mean of internal gap total (IGT) was 110.77(5.92) um for CAD/CAM group and 76.90 (10.17) um for conventional group. The Student's t-test revealed significant differences between 2 groups. Marginal and internal gaps were found to be significantly higher at all measured areas in CAD/CAM group than conventional group (p< 0.001). Within limitations of this study, conventional method of wax-pattern fabrication produced copings with significantly better marginal and internal fit than CAD/CAM (machine-milled) technique. All the factors for 2 groups were standardized except wax pattern fabrication technique, therefore, only the conventional group results in copings with clinically acceptable margins of less than 120um.

Comparison the Marginal and Internal Fit of Metal Copings Cast from Wax Patterns Fabricated by CAD/CAM and Conventional Wax up Techniques

PubMed Central

Vojdani, M; Torabi, K; Farjood, E; Khaledi, AAR

2013-01-01

Statement of Problem: Metal-ceramic crowns are most commonly used as the complete coverage restorations in clinical daily use. Disadvantages of conventional hand-made wax-patterns introduce some alternative ways by means of CAD/CAM technologies. Purpose: This study compares the marginal and internal fit of copings cast from CAD/CAM and conventional fabricated wax-patterns. Materials and Method: Twenty-four standardized brass dies were prepared and randomly divided into 2 groups according to the wax-patterns fabrication method (CAD/CAM technique and conventional method) (n=12). All the wax-patterns were fabricated in a standard fashion by means of contour, thickness and internal relief (M1-M12: representative of CAD/CAM group, C1-C12: representative of conventional group). CAD/CAM milling machine (Cori TEC 340i; imes-icore GmbH, Eiterfeld, Germany) was used to fabricate the CAD/CAM group wax-patterns. The copings cast from 24 wax-patterns were cemented to the corresponding dies. For all the coping-die assemblies cross-sectional technique was used to evaluate the marginal and internal fit at 15 points. The Student’s t- test was used for statistical analysis (α=0.05). Results: The overall mean (SD) for absolute marginal discrepancy (AMD) was 254.46 (25.10) um for CAD/CAM group and 88.08(10.67) um for conventional group (control). The overall mean of internal gap total (IGT) was 110.77(5.92) um for CAD/CAM group and 76.90 (10.17) um for conventional group. The Student’s t-test revealed significant differences between 2 groups. Marginal and internal gaps were found to be significantly higher at all measured areas in CAD/CAM group than conventional group (p< 0.001). Conclusion: Within limitations of this study, conventional method of wax-pattern fabrication produced copings with significantly better marginal and internal fit than CAD/CAM (machine-milled) technique. All the factors for 2 groups were standardized except wax pattern fabrication technique, therefore, only the conventional group results in copings with clinically acceptable margins of less than 120um. PMID:24724133

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.

Analytical Energy Dispersive X-Ray Fluorescence Measurements with a Scanty Amounts of Plant and Soil Materials

NASA Astrophysics Data System (ADS)

Mittal, R.; Rao, P.; Kaur, P.

2018-01-01

Elemental evaluations in scanty powdered material have been made using energy dispersive X-ray fluorescence (EDXRF) measurements, for which formulations along with specific procedure for sample target preparation have been developed. Fractional amount evaluation involves an itinerary of steps; (i) collection of elemental characteristic X-ray counts in EDXRF spectra recorded with different weights of material, (ii) search for linearity between X-ray counts and material weights, (iii) calculation of elemental fractions from the linear fit, and (iv) again linear fitting of calculated fractions with sample weights and its extrapolation to zero weight. Thus, elemental fractions at zero weight are free from material self absorption effects for incident and emitted photons. The analytical procedure after its verification with known synthetic samples of macro-nutrients, potassium and calcium, was used for wheat plant/ soil samples obtained from a pot experiment.

Recovery of manganese and zinc from spent Zn-C cell powder: Experimental design of leaching by sulfuric acid solution containing glucose.

PubMed

Biswas, Ranjit K; Karmakar, Aneek K; Kumar, Sree L

2016-05-01

The spent Zn-C cell powder, containing ZnMn2O4, ZnO, MnO(OH) and possibly Mn2O3 and Mn3O4, can be leached by a sulfuric acid solution mixed with some glucose. The leaching is found to be dependent on solid to liquid (S/L) ratio, amount of glucose, concentration of sulfuric acid solution, time and pulp agitation speed. For 5g powder (S), 1h leaching time and 300rpm pulp agitation speed, two-level four-factor (2(4)) experimental designs have been carried out to derive models for extraction of both Mn(II) and Zn(II). Amount of glucose (G, g), concentration of H2SO4 solution (C, mol/L), volume of H2SO4 solution as leachant (L, mL) and leaching temperature (T, °C) are considered as factors (variables). The model in both cases consists of mean, factor effects and interaction effects. The four-factor interaction effect is observed in neither of the cases. Some two-factor and three-factor effects are found to have produced positive or negative contributions to dissolution percentage in both cases. The models are examined for comparison with experimental results with good fits and also used for optimization of factors. At optimized condition (G=0.50g, C=2mol/L, L=250mL and T=100°C), an aliquot of 5g powder in 1h and at 300rpm produces a solution containing (7.08±0.10)g/L Mn(II) and (2.20±0.06)g/L Zn(II) corresponding to almost 100% extraction of both metal ions. Copyright © 2015 Elsevier Ltd. 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.

Optimizing adsorption of blue pigment from wastewater by nano-porous modified Na-bentonite using spectrophotometry based on response surface method

NASA Astrophysics Data System (ADS)

Moradi, Neshat; Salem, Shiva; Salem, Amin

2018-03-01

This work highlighted the effective activation of bentonite paste to produce nano-porous powder for removal of cationic dye from wastewater. The effects of activation parameters such as soda and moisture contents, ageing time and temperature were analyzed using response surface methodology (RSM). The significance of independent variables and their interactions were tested by blending the obtained powders with wastewater and then the adsorption was evaluated, spectrophotometrically. The experiments were carried out by preparation of pastes according to response surface methodology and central composite design, which is the standard method, was used to evaluate the effects and interactions of four factors on the treatment efficiency. RSM was demonstrated as an appropriate approach for optimization of alkali activation. The optimal conditions obtained from the desirable responses were 5.0 wt% soda and 45.0 wt% moisture, respectively in which the powder activation was carried out at 150 °C. In order to well understand the role of nano-structured material on dye removal, the adsorbents were characterized through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and Brunauer-Emmett-Teller surface area measurement. Finally, the analysis clearly demonstrates that the dye removal onto prepared adsorbent is well fitted with Langmuir isotherm compared to the other isotherm models. The low cost of material and facile process support the further development for commercial application purpose.

Exercise-Based Performance Enhancement and Injury Prevention for Firefighters: Contrasting the Fitness- and Movement-Related Adaptations to Two Training Methodologies.

PubMed

Frost, David M; Beach, Tyson A C; Callaghan, Jack P; McGill, Stuart M

2015-09-01

Using exercise to enhance physical fitness may have little impact on performers' movement patterns beyond the gym environment. This study examined the fitness and movement adaptations exhibited by firefighters in response to 2 training methodologies. Fifty-two firefighters were assigned to a movement-guided fitness (MOV), conventional fitness (FIT), or control (CON) group. Before and after 12 weeks of training, participants performed a fitness evaluation and laboratory-based test. Three-dimensional lumbar spine and frontal plane knee kinematics were quantified. Five whole-body tasks not included in the interventions were used to evaluate the transfer of training. FIT and MOV groups exhibited significant improvements in all aspects of fitness; however, only MOV exhibited improvements in spine and frontal plane knee motion control when performing each transfer task (effect sizes [ESs] of 0.2-1.5). FIT exhibited less controlled spine and frontal plane knee motions while squatting, lunging, pushing, and pulling (ES: 0.2-0.7). More MOV participants (43%) exhibited only positive posttraining changes (i.e., improved control), in comparison with FIT (30%) and CON (23%). Fewer negative posttraining changes were also noted (19, 25, and 36% for MOV, FIT, and CON). These findings suggest that placing an emphasis on how participants move while exercising may be an effective training strategy to elicit behavioral changes beyond the gym environment. For occupational athletes such as firefighters, soldiers, and police officers, this implies that exercise programs designed with a movement-oriented approach to periodization could have a direct impact on their safety and effectiveness by engraining desirable movement patterns that transfer to occupational tasks.

Metabolic rate covaries with fitness and the pace of the life history in the field

PubMed Central

Pettersen, Amanda K.; White, Craig R.; Marshall, Dustin J.

2016-01-01

Metabolic rate reflects the ‘pace of life’ in every organism. Metabolic rate is related to an organism's capacity for essential maintenance, growth and reproduction—all of which interact to affect fitness. Although thousands of measurements of metabolic rate have been made, the microevolutionary forces that shape metabolic rate remain poorly resolved. The relationship between metabolic rate and components of fitness are often inconsistent, possibly because these fitness components incompletely map to actual fitness and often negatively covary with each other. Here we measure metabolic rate across ontogeny and monitor its effects on actual fitness (lifetime reproductive output) for a marine bryozoan in the field. We also measure key components of fitness throughout the entire life history including growth rate, longevity and age at the onset of reproduction. We found that correlational selection favours individuals with higher metabolic rates in one stage and lower metabolic rates in the other—individuals with similar metabolic rates in each developmental stage displayed the lowest fitness. Furthermore, individuals with the lowest metabolic rates lived for longer and reproduced more, but they also grew more slowly and took longer to reproduce initially. That metabolic rate is related to the pace of the life history in nature has long been suggested by macroevolutionary patterns but this study reveals the microevolutionary processes that probably generated these patterns. PMID:27226476

The Neuronal Transition Probability (NTP) Model for the Dynamic Progression of Non-REM Sleep EEG: The Role of the Suprachiasmatic Nucleus

PubMed Central

Merica, Helli; Fortune, Ronald D.

2011-01-01

Little attention has gone into linking to its neuronal substrates the dynamic structure of non-rapid-eye-movement (NREM) sleep, defined as the pattern of time-course power in all frequency bands across an entire episode. Using the spectral power time-courses in the sleep electroencephalogram (EEG), we showed in the typical first episode, several moves towards-and-away from deep sleep, each having an identical pattern linking the major frequency bands beta, sigma and delta. The neuronal transition probability model (NTP) – in fitting the data well – successfully explained the pattern as resulting from stochastic transitions of the firing-rates of the thalamically-projecting brainstem-activating neurons, alternating between two steady dynamic-states (towards-and-away from deep sleep) each initiated by a so-far unidentified flip-flop. The aims here are to identify this flip-flop and to demonstrate that the model fits well all NREM episodes, not just the first. Using published data on suprachiasmatic nucleus (SCN) activity we show that the SCN has the information required to provide a threshold-triggered flip-flop for timing the towards-and-away alternations, information provided by sleep-relevant feedback to the SCN. NTP then determines the pattern of spectral power within each dynamic-state. NTP was fitted to individual NREM episodes 1–4, using data from 30 healthy subjects aged 20–30 years, and the quality of fit for each NREM measured. We show that the model fits well all NREM episodes and the best-fit probability-set is found to be effectively the same in fitting all subject data. The significant model-data agreement, the constant probability parameter and the proposed role of the SCN add considerable strength to the model. With it we link for the first time findings at cellular level and detailed time-course data at EEG level, to give a coherent picture of NREM dynamics over the entire night and over hierarchic brain levels all the way from the SCN to the EEG. PMID:21886801

Effects of self-superparasitism and host age on fitness-correlated traits in the solitary endoparasitoid wasp Meteorus pulchricornis.

PubMed

Zhang, Bo; Li, Baoping; Meng, Ling

2014-01-01

The domed fitness functions are suggested to describe developmental patterns of progeny parasitoids in relation to host age at oviposition in solitary koinobint parasitoids that are engaged in single parasitism, but few studies have investigated the applicability of the functions as related to superparasitism. The present study was designed to compare fitness functions between single parasitism and superparasitism by examining developmental patterns of Meteorus pulchricornis (Wesmael) (Hymneoptera: Braconidae) progeny in relation to the beet armyworm, Spodoptera exigua Hübner (Lepidoptera: Noctuidae), either singly parasitized or self-superparasitized as second-fifth instar larvae. Self-superparasitism caused deleterious effects on the fitness-related traits of parasitoid progeny, as demonstrated by a prolonged egg-to-adult emergence time, a smaller body size, and shorter longevity of the emerging adults, and decreased survival to adult emergence. While the domed fitness function was detected for development time, survival, adult body size, and longevity in relation to host larvae that were singly parasitized, the function was observed only for progeny survival in relation to host larvae that were self-superparasitized. This study suggests that developmental fitness functions with self-superparasitism can deviate from those with single parasitism in solitary koinobiont parasitoids.

Effects of selfsuperparasitism and host age on fitness-correlated traits in the solitary endoparasitoid wasp Meteorus pulchricornis

PubMed Central

Zhang, Bo; Li, Baoping; Meng, Ling

2014-01-01

Abstract The domed fitness functions are suggested to describe developmental patterns of progeny parasitoids in relation to host age at oviposition in solitary koinobint parasitoids that are engaged in single parasitism, but few studies have investigated the applicability of the functions as related to superparasitism. The present study was designed to compare fitness functions between single parasitism and superparasitism by examining developmental patterns of Meteorus pulchricornis (Wesmael) (Hymneoptera: Braconidae) progeny in relation to the beet armyworm, Spodoptera exigua Hübner (Lepidoptera: Noctuidae), either singly parasitized or self-superparasitized as second–fifth instar larvae. Selfsuperparasitism caused deleterious effects on the fitness-related traits of parasitoid progeny, as demonstrated by a prolonged egg-to-adult emergence time, a smaller body size, and shorter longevity of the emerging adults, and decreased survival to adult emergence. While the domed fitness function was detected for development time, survival, adult body size, and longevity in relation to host larvae that were singly parasitized, the function was observed only for progeny survival in relation to host larvae that were self-superparasitized. This study suggests that developmental fitness functions with selfsuperparasitism can deviate from those with single parasitism in solitary koinobiont parasitoids. PMID:25201512

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)

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

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.

Biosorption of copper ions from dilute aqueous solutions on base treated rubber (Hevea brasiliensis) leaves powder: kinetics, isotherm, and biosorption mechanisms.

PubMed

Wan Ngah, W S; Hanafiah, M A K M

2008-01-01

The efficiency of sodium hydroxide treated rubber (Hevea brasiliensis) leaves powder (NHBL) for removing copper ions from aqueous solutions has been investigated. The effects of physicochemical parameters on biosorption capacities such as stirring speed, pH, biosorbent dose, initial concentrations of copper, and ionic strength were studied. The biosorption capacities of NHBL increased with increase in pH, stirring speed and copper concentration but decreased with increase in biosorbent dose and ionic strength. The isotherm study indicated that NHBL fitted well with Langmuir model compared to Freundlich and Dubinin-Radushkevich models. The maximum biosorption capacity determined from Langmuir isotherm was 14.97 mg/g at 27 degrees C. The kinetic study revealed that pseudosecond order model fitted well the kinetic data, while Boyd kinetic model indicated that film diffusion was the main rate determining step in biosorption process. Based on surface area analysis, NHBL has low surface area and categorized as macroporous. Fourier transform infrared (FT-IR) analyses revealed that hydroxyl, carboxyl, and amino are the main functional groups involved in the binding of copper ions. Complexation was one of the main mechanisms for the removal of copper ions as indicated by FT-IR spectra. Ion exchange was another possible mechanism since the ratio of adsorbed cations (Cu2+ and H+) to the released cations (Na+, Ca2+, and Mg2+) from NHBL was almost unity. Copper ions bound on NHBL were able to be desorbed at > 99% using 0.05 mol/L HCl, 0.01 mol/L HNO3, and 0.01 mol/L EDTA solutions.

Morphology and phase behavior of ethanol nanodrops condensed on chemically patterned surfaces

NASA Astrophysics Data System (ADS)

Checco, Antonio; Ocko, Benjamin M.

2008-06-01

Equilibrium wetting of ethanol onto chemically patterned nanostripes has been investigated using environmental atomic force microscopy (AFM) in noncontact mode. The chemical patterns are composed of COOH-terminated “wetting” regions and CH3 -terminated “nonwetting” regions. A specially designed environmental AFM chamber allowed for accurate measurements of droplet height as a function of the temperature offset between the substrate and a macroscopic ethanol reservoir. At saturation, the height dependence scales with droplet width according to w1/2 , in excellent agreement with the augmented Young equation (AYE) modeled with dispersive, nonretarded surface potentials. At small under- and oversaturations, the AYE model accurately fits the data if an effective ΔT is used as a fitting parameter. There is a systematic difference between the measured ΔT and the values extracted from the fits to the data. In addition to static measurements, we present time-resolved measurements of the droplet height which enable the study of condensation-evaporation dynamics of nanometer-scale drops.

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

Environmental Factors Can Influence Mitochondrial Inheritance in the Saccharomyces Yeast Hybrids

PubMed Central

Hsu, Yu-Yi; Chou, Jui-Yu

2017-01-01

Mitochondria play a critical role in the generation of metabolic energy and are crucial for eukaryotic cell survival and proliferation. In most sexual eukaryotes, mitochondrial DNA (mtDNA) is inherited from only one parent in non-Mendelian inheritance in contrast to the inheritance of nuclear DNA. The model organism Saccharomyces cerevisiae is commonly used to study mitochondrial biology. It has two mating types: MATa and MATα. Previous studies have suggested that the mtDNA inheritance patterns in hybrid diploid cells depend on the genetic background of parental strains. However, the underlying mechanisms remain unclear. To elucidate the mechanisms, we examined the effects of environmental factors on the mtDNA inheritance patterns in hybrids obtained by crossing S. cerevisiae with its close relative S. paradoxus. The results demonstrated that environmental factors can influence mtDNA transmission in hybrid diploids, and that the inheritance patterns are strain dependent. The fitness competition assay results showed that the fitness differences can explain the mtDNA inheritance patterns under specific conditions. However, in this study, we found that fitness differences cannot fully be explained by mitochondrial activity in hybrids under stress conditions. PMID:28081193

Experience of Postpartum Active Duty Women in Training for the Fitness Assessment

DTIC Science & Technology

2014-09-10

fitness assessment after childbirth in order to develop a better understanding of this phenomenon. Design: This was phenomenological study and a...through Profound Life Transitions of Childbirth , and Seeking Understanding from Others. These patterns describe what it means to be an active duty...woman preparing for a fitness assessment after childbirth . Implications for Military Nursing: Results of this study can inform future nursing

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.

[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.

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…

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.

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.

Low dose aerosol fitness at the innate phase of murine infection better predicts virulence amongst clinical strains of Mycobacterium tuberculosis.

PubMed

Caceres, Neus; Llopis, Isaac; Marzo, Elena; Prats, Clara; Vilaplana, Cristina; de Viedma, Dario Garcia; Samper, Sofía; Lopez, Daniel; Cardona, Pere-Joan

2012-01-01

Evaluation of a quick and easy model to determine the intrinsic ability of clinical strains to generate active TB has been set by assuming that this is linked to the fitness of Mycobacterium tuberculosis strain at the innate phase of the infection. Thus, the higher the bacillary load, the greater the possibility of inducting liquefaction, and thus active TB, once the adaptive response is set. The virulence of seven clinical Mycobacterium tuberculosis strains isolated in Spain was tested by determining the bacillary concentration in the spleen and lung of mice at weeks 0, 1 and 2 after intravenous (IV) inoculation of 10⁴ CFU, and by determining the growth in vitro until the stationary phase had been reached. Cord distribution automated analysis showed two clear patterns related to the high and low fitness in the lung after IV infection. This pattern was not seen in the in vitro fitness tests, which clearly favored the reference strain (H37Rv). Subsequent determination using a more physiological low-dose aerosol (AER) inoculation with 10² CFU showed a third pattern in which the three best values coincided with the highest dissemination capacity according to epidemiological data. The fitness obtained after low dose aerosol administration in the presence of the innate immune response is the most predictive factor for determining the virulence of clinical strains. This gives support to a mechanism of the induction of active TB derived from the dynamic hypothesis of latent tuberculosis infection.

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).

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.

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.

Environmental heterogeneity blurs the signature of dispersal syndromes on spatial patterns of woody species in a moist tropical forest

PubMed Central

Velázquez, Eduardo; Escudero, Adrián; de la Cruz, Marcelino

2018-01-01

We assessed the relative importance of dispersal limitation, environmental heterogeneity and their joint effects as determinants of the spatial patterns of 229 species in the moist tropical forest of Barro Colorado Island (Panama). We differentiated five types of species according to their dispersal syndrome; autochorous, anemochorous, and zoochorous species with small, medium-size and large fruits. We characterized the spatial patterns of each species and we checked whether they were best fitted by Inhomogeneous Poisson (IPP), Homogeneous Poisson cluster (HPCP) and Inhomogeneous Poisson cluster processes (IPCP) by means of the Akaike Information Criterion. We also assessed the influence of species’ dispersal mode in the average cluster size. We found that 63% of the species were best fitted by IPCP regardless of their dispersal syndrome, although anemochorous species were best described by HPCP. Our results indicate that spatial patterns of tree species in this forest cannot be explained only by dispersal limitation, but by the joint effects of dispersal limitation and environmental heterogeneity. The absence of relationships between dispersal mode and degree of clustering suggests that several processes modify the original spatial pattern generated by seed dispersal. These findings emphasize the importance of fitting point process models with a different biological meaning when studying the main determinants of spatial structure in plant communities. PMID:29451871

Design and physicochemical characterization of advanced spray-dried tacrolimus multifunctional particles for inhalation

PubMed Central

Wu, Xiao; Hayes, Don; Zwischenberger, Joseph B; Kuhn, Robert J; Mansour, Heidi M

2013-01-01

The aim of this study was to design, develop, and optimize respirable tacrolimus microparticles and nanoparticles and multifunctional tacrolimus lung surfactant mimic particles for targeted dry powder inhalation delivery as a pulmonary nanomedicine. Particles were rationally designed and produced at different pump rates by advanced spray-drying particle engineering design from organic solution in closed mode. In addition, multifunctional tacrolimus lung surfactant mimic dry powder particles were prepared by co-dissolving tacrolimus and lung surfactant mimic phospholipids in methanol, followed by advanced co-spray-drying particle engineering design technology in closed mode. The lung surfactant mimic phospholipids were 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-sn-glycero-3-[phosphor-rac-1-glycerol]. Laser diffraction particle sizing indicated that the particle size distributions were suitable for pulmonary delivery, whereas scanning electron microscopy imaging indicated that these particles had both optimal particle morphology and surface morphology. Increasing the pump rate percent of tacrolimus solution resulted in a larger particle size. X-ray powder diffraction patterns and differential scanning calorimetry thermograms indicated that spray drying produced particles with higher amounts of amorphous phase. X-ray powder diffraction and differential scanning calorimetry also confirmed the preservation of the phospholipid bilayer structure in the solid state for all engineered respirable particles. Furthermore, it was observed in hot-stage micrographs that raw tacrolimus displayed a liquid crystal transition following the main phase transition, which is consistent with its interfacial properties. Water vapor uptake and lyotropic phase transitions in the solid state at varying levels of relative humidity were determined by gravimetric vapor sorption technique. Water content in the various powders was very low and well within the levels necessary for dry powder inhalation, as quantified by Karl Fisher coulometric titration. Conclusively, advanced spray-drying particle engineering design from organic solution in closed mode was successfully used to design and optimize solid-state particles in the respirable size range necessary for targeted pulmonary delivery, particularly for the deep lung. These particles were dry, stable, and had optimal properties for dry powder inhalation as a novel pulmonary nanomedicine. PMID:23403805

Structure-substitution limit correlation study on Cr{sup 3+} substituted polycrystalline yttrium iron garnet

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

Modi, K. B.; Saija, K. G.; Sharma, P. U.

2016-05-06

Polycrystalline samples of Cr{sup 3+} - substituted yttrium iron garnet (Y{sub 3}Fe{sub 5}O{sub 12}) system with general chemical formula, Y{sub 3}Fe{sub 5-x}Cr{sub x}O{sub 12}, x = 0.0, 0.2, 0.4 and 0.6 were synthesized by double sintering ceramic technique and characterized by X-ray powder diffractometry. The Rietveld fitted X-ray diffraction patterns analysis revealed mono phase formation for x = 0.0 - 0.4 compositions while x = 0.6 composition possesses mixed phase character. The observed substitution limit has been discussed in the light of ionic size of substituent, electrostatic energy, electronic configuration and synthesis parameters. These observations strongly suggest that the electronicmore » configuration of Cr{sup 3+}, which is favorable to the formation of d2sp3 (octahedral) type bonds, must be important. In the case of Cr{sup 3+}, the substitution does not appear to proceed well for x much greater than 0.5, this limitation probably is a consequence of the strong preference of a smaller ion Cr{sup 3+}, for a larger octahedral site which quickly leads to a condition not comparable with the requirement of the structure. The distribution of cations, mean ionic radii and theoretical lattice constant values have been determined.« less

[Keratoconus special soft contact lens fitting].

PubMed

Yamazaki, Ester Sakae; da Silva, Vanessa Cristina Batista; Morimitsu, Vagner; Sobrinho, Marcelo; Fukushima, Nelson; Lipener, César

2006-01-01

To evaluate the fitting and use of a soft contact lens in keratoconic patients. Retrospective study on 80 eyes of 66 patients, fitted with a special soft contact lens for keratoconus, at the Contact Lens Section of UNIFESP and private clinics. Keratoconus was classified according to degrees of disease severity by keratometric pattern. Age, gender, diagnosis, keratometry, visual acuity, spherical equivalent (SE), base curve and clinical indication were recorded. Of 66 patients (80 eyes) with keratoconus the mean age was 29 years, 51.5% were men and 48.5% women. According to the groups: 15.0% were incipient, 53.7% moderate, 26.3% advanced and 5.0% were severe. The majority of the eyes of patients using contact lenses (91.25%) achieved visual acuity better than 20/40. To 88 eyes 58% were tihed with lens with spherical power (mean -5.45 diopters) and 41% with spherocylinder power (from -0.5 to -5.00 cylindrical diopters). The most frequent base curve was 7.6 in 61% of the eyes. The main reasons for this special lens fitting were due to reduced tolerance and poor fitting pattern achieved with other lenses. The special soft contact lens is useful in fitting difficult keratoconic patients by offering comfort and improving visual rehabilitation that may allow more patients to postpone the need for corneal transplant.

Time-Resolved Transposon Insertion Sequencing Reveals Genome-Wide Fitness Dynamics during Infection.

PubMed

Yang, Guanhua; Billings, Gabriel; Hubbard, Troy P; Park, Joseph S; Yin Leung, Ka; Liu, Qin; Davis, Brigid M; Zhang, Yuanxing; Wang, Qiyao; Waldor, Matthew K

2017-10-03

Transposon insertion sequencing (TIS) is a powerful high-throughput genetic technique that is transforming functional genomics in prokaryotes, because it enables genome-wide mapping of the determinants of fitness. However, current approaches for analyzing TIS data assume that selective pressures are constant over time and thus do not yield information regarding changes in the genetic requirements for growth in dynamic environments (e.g., during infection). Here, we describe structured analysis of TIS data collected as a time series, termed pattern analysis of conditional essentiality (PACE). From a temporal series of TIS data, PACE derives a quantitative assessment of each mutant's fitness over the course of an experiment and identifies mutants with related fitness profiles. In so doing, PACE circumvents major limitations of existing methodologies, specifically the need for artificial effect size thresholds and enumeration of bacterial population expansion. We used PACE to analyze TIS samples of Edwardsiella piscicida (a fish pathogen) collected over a 2-week infection period from a natural host (the flatfish turbot). PACE uncovered more genes that affect E. piscicida 's fitness in vivo than were detected using a cutoff at a terminal sampling point, and it identified subpopulations of mutants with distinct fitness profiles, one of which informed the design of new live vaccine candidates. Overall, PACE enables efficient mining of time series TIS data and enhances the power and sensitivity of TIS-based analyses. IMPORTANCE Transposon insertion sequencing (TIS) enables genome-wide mapping of the genetic determinants of fitness, typically based on observations at a single sampling point. Here, we move beyond analysis of endpoint TIS data to create a framework for analysis of time series TIS data, termed pattern analysis of conditional essentiality (PACE). We applied PACE to identify genes that contribute to colonization of a natural host by the fish pathogen Edwardsiella piscicida. PACE uncovered more genes that affect E. piscicida 's fitness in vivo than were detected using a terminal sampling point, and its clustering of mutants with related fitness profiles informed design of new live vaccine candidates. PACE yields insights into patterns of fitness dynamics and circumvents major limitations of existing methodologies. Finally, the PACE method should be applicable to additional "omic" time series data, including screens based on clustered regularly interspaced short palindromic repeats with Cas9 (CRISPR/Cas9). Copyright © 2017 Yang et al.

Stochastic and Deterministic Crystal Structure Solution Methods in GSAS-II: Monte Carlo/Simulated Annealing Versus Charge Flipping

DOE PAGES

Von Dreele, Robert

2017-08-29

One of the goals in developing GSAS-II was to expand from the capabilities of the original General Structure Analysis System (GSAS) which largely encompassed just structure refinement and post refinement analysis. GSAS-II has been written almost entirely in Python loaded with graphics, GUI and mathematical packages (matplotlib, pyOpenGL, wxpython, numpy and scipy). Thus, GSAS-II has a fully developed modern GUI as well as extensive graphical display of data and results. However, the structure and operation of Python has required new approaches to many of the algorithms used in crystal structure analysis. The extensions beyond GSAS include image calibration/integration as wellmore » as peak fitting and unit cell indexing for powder data which are precursors for structure solution. Structure solution within GSAS-II begins with either Pawley or LeBail extracted structure factors from powder data or those measured in a single crystal experiment. Both charge flipping and Monte Carlo-Simulated Annealing techniques are available; the former can be applied to (3+1) incommensurate structures as well as conventional 3D structures.« less

Shielding small-field high-energy electron beams in cancer treatment

NASA Astrophysics Data System (ADS)

Farahani, M.; Eichmiller, F. C.; McLaughlin, W. L.

1994-04-01

The purpose of this study was to find an effective material that can be prepared quickly and easily prior to small-field electron-beam treatments so that lesions of the head and neck can be treated with minimal irradiation of the surrounding healthy tissue. Conventional preparation of custom anatomical prosthetic radiation shields, which are usually metal alloy masks, has been time-consuming and uncomfortable for the patients. New materials, made from light-body Reprosil TM (L. L. Caulk) filled with fine metal powder consisting of 70% Ag-30% Cu alloy, can be made by blending 90% (w/w) metal powder with 10% polysiloxane base and adding the polymerization catalyst separately. These combinations were mixed to form comfortably fitted shielding composites of different thicknesses. The electron-beam attenuation properties of slabs of this material were studied by irradiating calibrated radiochromic film (GafChromic TM) dosimeters behind different thicknesses of composite samples with small-field 13-, 15- and 18-MeV electron beams from a therapeutic linear accelerator. The results showed that this material can suitably attenuate high-energy electron beams when used in reasonable thicknesses.

Removal of phenol by powdered activated carbon prepared from coal gasification tar residue.

PubMed

Wang, Xiong-Lei; Shen, Jun; Niu, Yan-Xia; Wang, Yu-Gao; Liu, Gang; Sheng, Qing-Tao

2018-03-01

Coal gasification tar residue (CGTR) is a kind of environmentally hazardous byproduct generated in fixed-bed coal gasification process. The CGTR extracted by ethyl acetate was used to prepare powdered activated carbon (PAC), which is applied later for adsorption of phenol. The results showed that the PAC prepared under optimum conditions had enormous mesoporous structure, and the iodine number reached 2030.11 mg/g, with a specific surface area of 1981 m 2 /g and a total pore volume of 0.92 ml/g. Especially, without loading other substances, the PAC, having a strong magnetism, can be easily separated after it adsorbs phenol. The adsorption of phenol by PAC was studied as functions of contact time, temperature, PAC dosage, solution concentration and pH. The results showed a fast adsorption speed and a high adsorption capacity of PAC. The adsorption process was exothermic and conformed to the Freundlich models. The adsorption kinetics fitted better to the pseudo-second-order model. These results show that CGTR can be used as a potential adsorbent of phenols in wastewater.

Analysis of the plugging of the systems autonomy demonstration project brassboard filters

NASA Technical Reports Server (NTRS)

Clay, John C.

1989-01-01

A fine gray powder was clogging the brassboard filters. The powder appeared to be residue from a galvanic corrosive attack by ammonia of the aluminum and stainless steel components in the system. The corrosion was caused by water and chlorine that had entered into the system and combined with the ammonia. This combination made an electrolyte and a corrosive agent of the ammonia that attacked the metals in the system. The corroded material traveled through the system with the ammonia and clogged the filters. Key conclusions are: the debris collecting in the filters is a by-product of galvanic corrosion; the debris is principally corroded aluminum and stainless from the system; and galvanic corrosion occurred from water and chlorine that entered the system during normal and/or extreme operating and servicing conditions. Key recommendations are: use only one metal in the ammonia system-titanium, aluminum, or stainless steel; make the system as air-tight as possible (replace fittings with welded joints); and replace electron paramagnetic resonance (EPR) O-rings with neoprene O-rings, and do not use freon to clean system components.

Prototype Development of Remote Operated Hot Uniaxial Press (ROHUP) to Fabricate Advanced Tc-99 Bearing Ceramic Waste Forms - 13381

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

Alaniz, Ariana J.; Delgado, Luc R.; Werbick, Brett M.

The objective of this senior student project is to design and build a prototype construction of a machine that simultaneously provides the proper pressure and temperature parameters to sinter ceramic powders in-situ to create pellets of rather high densities of above 90% (theoretical). This ROHUP (Remote Operated Hot Uniaxial Press) device is designed specifically to fabricate advanced ceramic Tc-99 bearing waste forms and therefore radiological barriers have been included in the system. The HUP features electronic control and feedback systems to set and monitor pressure, load, and temperature parameters. This device operates wirelessly via portable computer using Bluetooth{sup R} technology.more » The HUP device is designed to fit in a standard atmosphere controlled glove box to further allow sintering under inert conditions (e.g. under Ar, He, N{sub 2}). This will further allow utilizing this HUP for other potential applications, including radioactive samples, novel ceramic waste forms, advanced oxide fuels, air-sensitive samples, metallic systems, advanced powder metallurgy, diffusion experiments and more. (authors)« less

Synthesis of a novel alginate-rubber joint immobilization strains H-1 and its application in removal of Pb (II) from aqueous solution

NASA Astrophysics Data System (ADS)

Li, Huidong; Huo, Kaili; Li, Xiaolei; Zhang, Lin; Yun, Yueqing; Song, Lei; Bai, Runying; Liu, Yuhong

2018-02-01

In this study, a novel alginate-rubber-strains immobilized beads (ARSIBs) was synthesized at the optimum conditions that the concentration of sodium alginate was 4%; the volume of bacterial suspension was 75%; the quality of rubber powder was 3.2%; the crosslinking time was 24 h by the orthogonal experiments. The optimum conditions for Pb (II) adsorption were 1.2% ARSIBs, 100 mg L-1 initial concentrations, pH 5 and 3 h contact time. The equilibrium data were well fitted by the Freundlich isotherm model. The biosorption process was nearly consistent with the pseudo-second-order model. Meanwhile, the biosorption mechanism could be that Pb (II) was adsorbed by the hydroxyl and carboxyl, finally precipitated with phosphate in the form of NaPb4(PO4)3, Pb5(PO4)3(OH) and Pb(H2PO4)2 based on the spectra of FTIR and XRD, respectively. In addition, the stability of ARSIBs was enhanced due to the addition to the rubber powder in the process of wastewater treatment.

Moisture Sorption and Thermodynamic Properties of Vacuum-Dried Capsosiphon fulvescens Powder

PubMed Central

Zuo, Li; Rhim, Jong-Whan; Lee, Jun Ho

2015-01-01

The moisture sorption isotherms of vacuum-dried edible green alga (Capsosiphon fulvescens) powders were determined at 25, 35, and 45°C and water activity (aw) in the range of 0.11~0.94. An inversion effect of temperature was found at high water activity (>0.75). Various mathematical models were fitted to the experimental data, and Brunauer, Emmett, and Teller model was found to be the most suitable model describing the relationship between equilibrium moisture content and water activity (<0.45). Henderson model could also provide excellent agreement between the experimental and predicted values despite of the intersection point. Net isosteric heat of adsorption decreased from 15.77 to 9.08 kJ/mol with an increase in equilibrium moisture content from 0.055 to 0.090 kg H2O/kg solids. The isokinetic temperature (Tβ) was 434.79 K, at which all the adsorption reactions took place at the same rate. The enthalpy-entropy compensation suggested that the mechanism of the adsorption process was shown to be enthalpy-driven. PMID:26451360

Direct fitness benefits explain mate preference, but not choice, for similarity in heterozygosity levels.

PubMed

Zandberg, Lies; Gort, Gerrit; van Oers, Kees; Hinde, Camilla A

2017-10-01

Under sexual selection, mate preferences can evolve for traits advertising fitness benefits. Observed mating patterns (mate choice) are often assumed to represent preference, even though they result from the interaction between preference, sampling strategy and environmental factors. Correlating fitness with mate choice instead of preference will therefore lead to confounded conclusions about the role of preference in sexual selection. Here we show that direct fitness benefits underlie mate preferences for genetic characteristics in a unique experiment on wild great tits. In repeated mate preference tests, both sexes preferred mates that had similar heterozygosity levels to themselves, and not those with which they would optimise offspring heterozygosity. In a subsequent field experiment where we cross fostered offspring, foster parents with more similar heterozygosity levels had higher reproductive success, despite the absence of assortative mating patterns. These results support the idea that selection for preference persists despite constraints on mate choice. © 2017 The Authors Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Proceedings of the Second Annual Symposium on Mathematical Pattern Recognition and Image Analysis Program

NASA Technical Reports Server (NTRS)

Guseman, L. F., Jr. (Principal Investigator)

1984-01-01

Several papers addressing image analysis and pattern recognition techniques for satellite imagery are presented. Texture classification, image rectification and registration, spatial parameter estimation, and surface fitting are discussed.

EVALUATION OF CASES WITH THE USAGE OF COMMERCIALLY AVAILABLE TABLETS IN THE PEDIATRIC FORMULA.

PubMed

Kuriata, Elżbieta; Sawicki, Wiesław

2015-01-01

Lack of availability, of either the medicinal product intended to be used for children, or such in a dose which is fitting for the individual child's needs, results in physicians administering medicines meant for the adult. The target of the thesis was to evaluate the cases with the usage of commercially avaible conventional tablet-formulated medicinal products intended for the adult in the pediatric formula. The subjects of the evaluation were the form of the pediatric drug, prepared from commercially available tablets and capsules, as well as the legitimacy of their usage in the treatment of the pediatric population. One hundred and fifty-four prescriptions filled in community pharmacies of Warminsko-Mazurskie Voivodeship in 2011 were chosen. A total of 5805 divided powders in starch capsules were prepared. The prescribing practice included 6 groups of manufactured medicinal products in the form of conventional tablets, containing as follows: anti-hypertensive medicines (ACE inhibitors--enalapril, captopril, ramipril, loop diuretics--furosemide, potassium sparing diuretics--spironolactone, β-adrenolytics--propranolol, α- and β-adrenolytics--carvedilol), medicines for heart failure (foxglove glycosides--digoxin, methyldigoxin), anti-clotting medicines (acetylsalicylic acid), peristalsis stimulating agents (metoclopramide), antibacterial medicines (furagin), and dopaminergic (carbidopa-levodopa). The only compounded forms ordered by the physicians were divided powders for an internal use. Starch capsules for powder preparation provided the only 'package' for the dose of the compounded powder, which after pouring, solving or suspending in water was administered to children. Such a shift of the form, between an oral tablet and divided powder for an internal use, did not cause a change in the method of administration. The information on indications and the way of dosage for children, inserted in the Summary of Product Characteristics, enables the administration which follows the registered indications, despite the shortage of an appropriate dose in the pharmaceutical market. In contrast, an absence of the information regarding the indications and a dosage for children in the Summary of Product Characteristic, results in an off-label administration, in case of a child.

Oxidized nanocrystalline Fe-Cu pseudoalloy subjected to high pressure and electrodischarge pulses: Mössbauer and x-ray investigations

NASA Astrophysics Data System (ADS)

Gavriliuk, A. G.; Voitkovsky, V. S.; Sidorov, V. A.; Filonenko, V. P.; Tsiok, O. B.; Khvostantsev, L. G.

1998-05-01

Nanocrystalline Fe15Cu85 pseudoalloy has been subjected to pulsed heating up to 1500 K at high pressure (8 GPa). Two regimes were studied: the direct heating using electrodischarge through the sample and indirect heating with the use of cylindrical heater around the sample. The temperature and time conditions in both types of experiments were adjusted to be equivalent. The discharge parameters (stored energy, discharge time, and magnitude of current pulse) were sufficient to move defects by conduction electrons, but insufficient to melt the sample. The properties of treated samples were studied using Mössbauer absorption spectra and x-ray diffraction for three types of samples: (a) primary powder treated by high pressure up to 8 GPa, (b) powder subjected to indirect pulsed heating at 8 GPa, (c) powder treated by electrical pulses at 8 GPa. The x-ray diffraction pattern of primary powder exhibits peaks of copper, iron, and copper oxide (CuO). The Mössbauer spectrum of primary powder exhibits six peaks of alpha iron and some peaks near zero velocity due to the small iron clusters in the copper matrix and ultrafine clusters of paramagnetic phase x-Fe2O3. The transformation of CuO to Cu2O takes place in the course of indirect heating, the Mössbauer spectrum being almost unchanged. The direct electrodischarge heating causes the appearance of new magnetic phase with the magnetic field on iron nucleus 505 kOe, which corresponds to α-Fe2O3. The formation of α-Fe2O3 was confirmed by x-ray diffraction. At the same time the transformation of CuO to Cu2O is incomplete. These experiments demonstrate that high density current pulses, causing the electron wind, can be a useful tool to influence the structure of nanocrystalline powder.

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.

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.

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

A general method for baseline-removal in ultrafast electron powder diffraction data using the dual-tree complex wavelet transform.

PubMed

René de Cotret, Laurent P; Siwick, Bradley J

2017-07-01

The general problem of background subtraction in ultrafast electron powder diffraction (UEPD) is presented with a focus on the diffraction patterns obtained from materials of moderately complex structure which contain many overlapping peaks and effectively no scattering vector regions that can be considered exclusively background. We compare the performance of background subtraction algorithms based on discrete and dual-tree complex (DTCWT) wavelet transforms when applied to simulated UEPD data on the M1-R phase transition in VO 2 with a time-varying background. We find that the DTCWT approach is capable of extracting intensities that are accurate to better than 2% across the whole range of scattering vector simulated, effectively independent of delay time. A Python package is available.

Processing Bi-Pb-Sr-Ca-Cu-O superconductors from amorphous state

NASA Technical Reports Server (NTRS)

Chiang, C. K.; Wong-Ng, W.; Cook, L. P.; Freiman, S. W.; Hwang, N. M.; Vaudin, M.; Hill, M. D.; Shull, R. D.; Shapiro, A. J.; Swartzendruber, L. J.

1991-01-01

The bismuth based high T sub c superconductors can be processed via an amorphous Bi-Pb-Sr-Ca-Cu oxide. The amorphous oxides were prepared by melting the constituent powders in an alumina crucible at 1200 C in air followed by pouring the liquid onto an aluminum plate, and rapidly pressing with a second plate. In the amorphous state, no crystalline phase was identified in the powder x ray diffraction pattern of the quenched materials. After heat treatment at high temperature the amorphous materials crystallized into a glass ceramic containing a large fraction of the Bi2Sr2Ca2Cu3O(x) phase T sub c = 110 K. The processing method, crystallization, and results of dc electrical resistivity and ac magnetic susceptibility measurements are discussed.

3D Product Development for Loose-Fitting Garments Based on Parametric Human Models

NASA Astrophysics Data System (ADS)

Krzywinski, S.; Siegmund, J.

2017-10-01

Researchers and commercial suppliers worldwide pursue the objective of achieving a more transparent garment construction process that is computationally linked to a virtual body, in order to save development costs over the long term. The current aim is not to transfer the complete pattern making step to a 3D design environment but to work out basic constructions in 3D that provide excellent fit due to their accurate construction and morphological pattern grading (automatic change of sizes in 3D) in respect of sizes and body types. After a computer-aided derivation of 2D pattern parts, these can be made available to the industry as a basis on which to create more fashionable variations.

Emotional fit with culture: a predictor of individual differences in relational well-being.

PubMed

De Leersnyder, Jozefien; Mesquita, Batja; Kim, Heejung; Eom, Kimin; Choi, Hyewon

2014-04-01

There is increasing evidence for emotional fit in couples and groups, but also within cultures. In the current research, we investigated the consequences of emotional fit at the cultural level. Given that emotions reflect people's view on the world, and that shared views are associated with good social relationships, we expected that an individual's fit to the average cultural patterns of emotion would be associated with relational well-being. Using an implicit measure of cultural fit of emotions, we found across 3 different cultural contexts (United States, Belgium, and Korea) that (1) individuals' emotional fit is associated with their level of relational well-being, and that (2) the link between emotional fit and relational well-being is particularly strong when emotional fit is measured for situations pertaining to relationships (rather than for situations that are self-focused). Together, the current studies suggest that people may benefit from emotionally "fitting in" to their culture.

Descriptive analysis of the type and design of contact lenses fitted according to keratoconus severity and morphology.

PubMed

Lunardi, Letícia Helena; Arroyo, Danielle; Andrade Sobrinho, Marcelo Vicente de; Lipener, César; Rosa, Juliana Maria da Silva

2016-04-01

Keratoconus is characterized by bilateral asymmetrical corneal ectasia that leads to inferior stromal thinning and corneal protrusion. There is currently a lack of consensus regarding the most efficacious method for fitting contact lenses in patients with keratoconus, given the various topographical patterns and evolution grades observed in affected populations. The purpose of the present study was to evaluate the association between keratoconus evolution grade and topography pattern and the type and design of fitted contact lens. We performed a retrospective analysis of contact lenses fitted in a total of 185 patients with keratoconus (325 eyes). Keratoconus was classified as either grade I, II, III, or IV based on keratometry and cone morphology (nipple, oval, globus, or indeterminate) results. A total of 325 eyes were evaluated in the present study. Of the 62 eyes classified as grade I, 66.1% were fitted with monocurve contact lenses. Of the 162 eyes classified as grade I and II, 51%, 30%, and 19% were fitted with adapted monocurve rigid gas-permeable contact lenses (RGPCL), bicurve lenses, and others lens types, respectively. Bicurve lenses were fitted in 52.1% and 62.2% of eyes classified as grade III and IV, respectively. Of the eyes classified as grade III and IV, monocurve and bicurve RGPCL were fitted in 26% and 55%, respectively. In eyes with oval keratoconus, 45%, 35%, and 20% were fitted with monocurve lenses, bicurve lenses, and other lens types, respectively. In eyes with round cones (nipple morphology), 55%, 30%, and 15% were fitted with bicurve lenses, monocurve lenses, and other lens types, respectively. Monocurve RGPCL were most frequently fitted in patients with mild to moderate keratoconus and oval cones morphology, while bicurve lenses were more frequently fitted in patients with severe and advanced keratoconus. This was probably because bicurve lenses are more appropriate for round cones due to increased corneal asphericity.

Marginal and internal fit of pressed lithium disilicate inlays fabricated with milling, 3D printing, and conventional technologies.

PubMed

Homsy, Foudda R; Özcan, Mutlu; Khoury, Marwan; Majzoub, Zeina A K

2018-05-01

The subtractive and additive computer-aided design and computer-aided manufacturing (CAD-CAM) of lithium disilicate partial coverage restorations is poorly documented. The purpose of this in vitro study was to compare the marginal and internal fit accuracy of lithium disilicate glass-ceramic inlays fabricated with conventional, milled, and 3-dimensional (3D) printed wax patterns. A dentoform mandibular first molar was prepared for a mesio-occlusal ceramic inlay. Five groups of 15 inlays were obtained through conventional impression and manual wax pattern (group CICW); conventional impression, laboratory scanning of the stone die, CAD-CAM milled wax blanks (group CIDW) or 3D printed wax patterns (group CI3DW); and scanning of the master preparation with intraoral scanner and CAD-CAM milled (group DSDW) or 3D printed wax patterns (group DS3DW). The same design was used to produce the wax patterns in the last 4 groups. The replica technique was used to measure marginal and internal adaptation by using stereomicroscopy. Mixed-model ANOVA was used to assess differences according to the groups and discrepancy location (α=.05). Group DSDW showed the smallest marginal discrepancy (24.3 μm) compared with those of groups CICW (45.1 μm), CIDW (33.7 μm), CI3DW (39.8 μm), and DS3DW (39.7 μm) (P<.001). No statistically significant differences were detected among groups CICW, CIDW, CI3DW, and DS3DW relative to the marginal discrepancy. The internal discrepancy was significantly larger than the marginal discrepancy within all groups (P<.001). Lithium disilicate glass-ceramic inlays produced from digital scans and subtractive milling of wax patterns resulted in better marginal and internal fit accuracy than either conventional impression/fabrication or additive 3D manufacturing. Three-dimensional printed wax patterns yielded fit values similar to those of the conventionally waxed inlays. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Preparation of regenerable granular carbon nanotubes by a simple heating-filtration method for efficient removal of typical pharmaceuticals

NASA Astrophysics Data System (ADS)

Shan, Danna; Deng, Shubo; Zhao, Tianning; Yu, Gang; Winglee, Judith; Wiesner, Mark R.

2017-04-01

A simple and convenient method was used to prepare novel granular carbon nanotubes (CNTs) for enhanced adsorption of pharmaceuticals. By heating CNTs powder at 450 degree centigrade in air, followed by filtration, the obtained granular adsorbent exhibited high surface area and pore volume since the heating process produced some oxygen-containing functional groups on CNT surface, making CNTs more dispersible in the formation of granular cake. The porous granular CNTs not only had more available surfaces for adsorption but also were more easily separated from solution than pristine CNTs (p-CNTs) powder. This adsorbent exhibited relatively fast adsorption for carbamazepine (CBZ), tetracycline (TC) and diclofe- nac sodium (DS), and the maximum adsorption capacity on the granular CNTs was 369.5 μmol/g for CBZ, 284.2 μmol/g for TC and 203.1 μmol/g for DS according to the Langmuir fitting, increasing by 42.4%, 37.8% and 38.0% in comparison with the pristine CNTs powder. Moreover, the spent granular CNTs were successfully regenerated at 400 degree centigrade in air without decreasing the adsorption capacity in five regeneration cycles. The adsorbed CBZ and DS were completely degraded, while the adsorbed TC was partially oxidized and the residual was favorable for the subsequent adsorption. This research develops an easy method to prepare and regenerate granular CNT adsorbent for the enhanced removal of organic pollutants from water or wastewater.

Utilization of powdered waste sludge (PWS) for removal of textile dyestuffs from wastewater by adsorption.

PubMed

Ozmihci, Serpil; Kargi, Fikret

2006-11-01

Acid pre-treated powdered waste sludge (PWS) was used for removal of textile dyestuffs from aqueous medium by adsorption as an alternative to the use of powdered activated carbon (PAC). The rate and extent of dysetuff removals were determined for four different dyestuffs at different PWS concentrations varying between 1 and 6 gl(-1). Biosorbed dyestuff concentrations at equilibrium decreased with increasing PWS concentration for all dyestuffs tested. PWS was more effective for adsorption of Remazol red RR and Chrisofonia direct yellow 12 as compared to the other dyestuffs tested. More than 80% percent dyestuff removal was obtained for all dyestuffs at PWS concentrations above 4 gl(-1) after 6h of incubation. Similar to percent dyestuff removal, the rate of adsorption was maximum at a PWS concentration of 4 gl(-1). Kinetics of adsorption of dyestuffs was investigated by using the first- and second-order kinetic models and the kinetic constants were determined. Second-order kinetics was found to fit the experimental data better than the first-order model for all dyestuffs tested. Adsorption isotherms were established for all dyestuffs used and the isotherm constants were determined by using the experimental data. Langmuir and the generalized adsorption isotherms were found to be more suitable than the Freundlich isotherm for correlation of equilibrium adsorption data. Acid pre-treated PWS was proven to be an effective adsorbent for dyestuff removal as compared to the other adsorbents reported in literature studies.

Aersol Jet Deposition of Geramic Thin Films for Electromechanical Applications

DTIC Science & Technology

2012-03-01

Ethyl Cellulose (EC) were utilized as binder and plasticizer constituents. Inks were prepared by the addition of powders, to the combination of...0 NiO 0 0 0 0 0 0 34.6 LSM Disperbyk-111 Solsperse-3000 Dispex-A40 Ethyl Cellulose 0 0 0 0 0.21 0 0 0.56 0 0.21 0 0.56 0 0 0.21 0 0 0 0.56 0.21...of pattern filling was done by using a spiral fill (Fig 3d , e, f.). For this, a decagonal pattern was generated using AutoCAD® polyline segments

Using Structural Equation Modeling To Fit Models Incorporating Principal Components.

ERIC Educational Resources Information Center

Dolan, Conor; Bechger, Timo; Molenaar, Peter

1999-01-01

Considers models incorporating principal components from the perspectives of structural-equation modeling. These models include the following: (1) the principal-component analysis of patterned matrices; (2) multiple analysis of variance based on principal components; and (3) multigroup principal-components analysis. Discusses fitting these models…

Improved tests reveal that the accelarating moment release hypothesis is statistically insignificant

USGS Publications Warehouse

Hardebeck, J.L.; Felzer, K.R.; Michael, A.J.

2008-01-01

We test the hypothesis that accelerating moment release (AMR) is a precursor to large earthquakes, using data from California, Nevada, and Sumatra. Spurious cases of AMR can arise from data fitting because the time period, area, and sometimes magnitude range analyzed before each main shock are often optimized to produce the strongest AMR signal. Optimizing the search criteria can identify apparent AMR even if no robust signal exists. For both 1950-2006 California-Nevada M ??? 6.5 earthquakes and the 2004 M9.3 Sumatra earthquake, we can find two contradictory patterns in the pre-main shock earthquakes by data fitting: AMR and decelerating moment release. We compare the apparent AMR found in the real data to the apparent AMR found in four types of synthetic catalogs with no inherent AMR. When spatiotemporal clustering is included in the simulations, similar AMR signals are found by data fitting in both the real and synthetic data sets even though the synthetic data sets contain no real AMR. These tests demonstrate that apparent AMR may arise from a combination of data fitting and normal foreshock and aftershock activity. In principle, data-fitting artifacts could be avoided if the free parameters were determined from scaling relationships between the duration and spatial extent of the AMR pattern and the magnitude of the earthquake that follows it. However, we demonstrate that previously proposed scaling relationships are unstable, statistical artifacts caused by the use of a minimum magnitude for the earthquake catalog that scales with the main shock magnitude. Some recent AMR studies have used spatial regions based on hypothetical stress loading patterns, rather than circles, to select the data. We show that previous tests were biased and that unbiased tests do not find this change to the method to be an improvement. The use of declustered catalogs has also been proposed to eliminate the effect of clustering but we demonstrate that this does not increase the statistical significance of AMR. Given the ease with which data fitting can find desired patterns in seismicity, future studies of AMR-like observations must include complete tests against synthetic catalogs that include spatiotemporal clustering.

High energy cathode material

DOEpatents

Li, Bin; Caldwell, Marissa; Tong, Wei; Kaye, Steven; Bhat, Vinay

2015-09-01

A composition for use in a battery electrode comprising a compound including lithium, manganese, nickel, and oxygen. The composition is characterized by a powder X-ray diffraction pattern having peaks including 18.6.+-.0.2, 35.0.+-.0.2, 36.4.+-.0.2, 37.7.+-.0.2, 42.1.+-.0.2, and 44.5.+-.0.2 degrees 2.theta. as measured using Cu K.sub..alpha. radiation.

A high-resolution (13)C 3D CSA-CSA-CSA correlation experiment by means of magic angle turning.

PubMed

Hu, J Z; Ye, C; Pugmire, R J; Grant, D M

2000-08-01

It is shown in this paper that a previously reported 90 degrees sample flipping (13)C 2D CSA-CSA correlation experiment may be carried out alternatively by employing constant slow sample rotation about the magic angle axis and by synchronizing the read pulse to 13 of the rotor cycle. A high-resolution 3D CSA-CSA-CSA correlation experiment based on the magic angle turning technique is reported in which the conventional 90 degrees 2D CSA-CSA powder pattern for each carbon in a system containing a number of inequivalent carbons may be separated according to the isotropic chemical shift value. The technique is demonstrated on 1,2,3-trimethoxybenzene in which all of the overlapping powder patterns that cannot be segregated by the 2D CSA-CSA experiment are resolved successfully by the 3D CSA-CSA-CSA experiment, including even the two methoxy groups (M(1) and M(3)) whose isotropic shifts, confirmed by high-speed MAS, are separated by only 1 ppm. A difference of 4 ppm in the principal value component (delta(33)) between M(1) and M(3) is readily obtained. Copyright 2000 Academic Press.

Novel interpretation of the mean structure of feroxyhyte

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

Sestu, Matteo, E-mail: msestu@unica.it; Carta, Daniela; Casula, Maria F.

2015-05-15

The structure of the iron oxyhydroxide called feroxyhyte (δ-FeOOH), which shows an elusive X-ray powder diffraction pattern, has been represented so far using models describing a mean structure based on the crystalline network of the iron(III) oxide hematite (α-Fe{sub 2}O{sub 3}). In this paper, a novel description of the mean structure of feroxyhyte is presented, which is based on the structure of the thermodynamically stable iron oxyhydroxide goethite. Starting from different local arrangements present in the goethite network, a mean structural model is determined which shows an X-ray powder diffraction pattern almost coincident with previous studies. This outcome enables tomore » integrate the structure of feroxyhyte among those of other well characterized iron oxyhydroxides. - Graphical abstract: The structure of the iron oxy-hydroxide feroxyhyte can be described by local arrangements present in the goethite network. - Highlights: • The structure of feroxyhyte (δ-FeOOH) proposed in literature is discussed. • The structure of goethite (α-FeOOH) is analyzed. • A structural relationship between feroxyhyte and goethite is found. • New interpretation of the mean structure of δ-FeOOH is given.« less

Low temperature method for the production of calcium phosphate fillers

PubMed Central

Calafiori, Anna Rita; Marotta, Marcello; Nastro, Alfonso; Martino, Guglielmo

2004-01-01

Background Calcium phosphate manufactured samples, prepared with hydroxyapatite, are used as either spacers or fillers in orthopedic surgery, but these implants have never been used under conditions of mechanical stress. Similar conditions also apply with cements. Many authors have postulated that cements are a useful substitute material when implanted in vivo. The aim of this research is to develop a low cristalline material similar to bone in porosity and cristallinity. Methods Commercial hydroxyapatite (HAp) and monetite (M) powders are mixed with water and compacted to produce cylindrical samples. The material is processed at a temperature of 37–120 degrees C in saturated steam to obtain samples that are osteoconductive. The samples are studied by X-ray powder diffraction (XRD), Vickers hardness test (HV), scanning electron microscopy (SEM), and porosity evaluation. Results The X-ray diffractions of powders from the samples show patterns typical of HAp and M powders. After thermal treatment, no new crystal phase is formed and no increase of the relative intensity of the peaks is obtained. Vicker hardness data do not show any relationship with treatment temperature. The total porosity decreases by 50–60% according to the specific thermal treatment. Scanning electron microscopy of the surfaces of the samples with either HAp 80%-M 20% (c) or Hap 50%-M 50% (f), show cohesion of the powder grains. Conclusions The dissolution-reprecipitation process is more intesive in manufactured samples (c) and (f), according to Vickers hardness data. The process occurs in a steam saturated environment between 37 degrees and 120 degrees C. (c) (f) manufactured samples show pore dimension distributions useful to cellular repopulation in living tissues. PMID:15035671

Application of powder X-ray diffraction in studying the compaction behavior of bulk pharmaceutical powders.

PubMed

Bandyopadhyay, Rebanta; Selbo, Jon; Amidon, Gregory E; Hawley, Michael

2005-11-01

This study investigates the effects of crystal lattice deformation on the powder X-ray diffraction (PXRD) patterns of compressed polycrystalline specimen (compacts/tablets) made from molecular, crystalline powders. The displacement of molecules and the corresponding adjustment of interplanar distances (d-spacings) between diffracting planes of PNU-288034 and PNU-177553, which have crystal habits with a high aspect ratio favoring preferred orientation during tableting, are demonstrated by shifts in the diffracted peak positions. The direction of shift in diffracted peak positions suggests a reduction of interplanar d-spacing in the crystals of PNU-288034 and PNU-177553 following compaction. There is also a general reduction of peak intensities following compression at the different compressive loads. The lattice strain representing the reduction in d-spacing is proportional to the original d-spacing of the uncompressed sample suggesting that, as with systems that obey a simple Hooke's law relationship, the further apart the planes of atoms/molecules within the lattice are, the easier it is for them to approach each other under compressive stresses. For a third model compound comprising more equant-shaped crystals of PNU-141659, the shift in diffracted peak positions are consistent with an expansion of lattice spacing after compression. This apparent anomaly is supported by the PXRD studies of the bulk powder consisting of fractured crystals where also, the shift in peak position suggests expansion of the lattice planes. Thus the crystals of PNU-141659 may be fracturing under the compressive loads used to produce the compacts. Additional studies are underway to relate the PXRD observations with the bulk tableting properties of these model compounds.

Preparation and Evaluation of Surface Modified Lactose Particles for Improved Performance of Fluticasone Propionate Dry Powder Inhaler.

PubMed

Singh, Deepak J; Jain, Rajesh R; Soni, P S; Abdul, Samad; Darshana, Hegde; Gaikwad, Rajiv V; Menon, Mala D

2015-08-01

Dry powder inhalers (DPI) are generally formulated by mixing micronized drug particles with coarse lactose carrier particles to assist powder handling during the manufacturing and powder aerosol delivery during patient use. In the present study, surface modified lactose (SML) particles were produced using force control agents, and their in vitro performance on dry powder inhaler (DPI) formulation of Fluticasone propionate was studied. With a view to reduce surface passivation of high surface free energy sites on the most commonly used DPI carrier, α- lactose monohydrate, effects of various force control agents such as Pluronic F-68, Cremophor RH 40, glyceryl monostearate, polyethylene glycol 6000, magnesium stearate, and soya lecithin were studied. DPI formulations prepared with SML showed improved flow properties, and atomic force microscopy (AFM) studies revealed decrease in surface roughness. The DSC and X-ray diffraction patterns of SML showed no change in the crystal structure and thermal behavior under the experimental conditions. The fine particle fraction (FPF) values of lactose modified with Pluronic F-68, Cremophor RH 40, glyceryl monostearate were improved, with increase in concentration up to 0.5%. Soya lecithin and PEG 6000 modified lactose showed decrease in FPF value with increase in concentration. Increase in FPF value was observed with increasing concentration of magnesium stearate. Two different DPI devices, Rotahaler(®) and Diskhaler(®), were compared to evaluate the performance of SML formulations. FPF value of all SML formulations were higher using both devices as compared to the same formulations prepared using untreated lactose. One month stability of SML formulations at 40°C/75% RH, in permeable polystyrene tubes did not reveal any significant changes in FPF values. SML particles can help in reducing product development hindrances and improve inhalational properties of DPI.

Factors Influencing Running-Related Musculoskeletal Injury Risk Among U.S. Military Recruits.

PubMed

Molloy, Joseph M

2016-06-01

Running-related musculoskeletal injuries among U.S. military recruits negatively impact military readiness. Low aerobic fitness, prior injury, and weekly running distance are known risk factors. Physical fitness screening and remedial physical training (or discharging the most poorly fit recruits) before entry-level military training have tended to reduce injury rates while decreasing attrition, training, and medical costs. Incorporating anaerobic running sessions into training programs can offset decreased weekly running distance and decrease injury risk. Varying lower extremity loading patterns, stride length or cadence manipulation, and hip stability/strengthening programming may further decrease injury risk. No footstrike pattern is ideal for all runners; transitioning to forefoot striking may reduce risk for hip, knee, or tibial injuries, but increase risk for calf, Achilles, foot or ankle injuries. Minimal evidence associates running surfaces with injury risk. Footwear interventions should focus on proper fit and comfort; the evidence does not support running shoe prescription per foot type to reduce injury risk among recruits. Primary injury mitigation efforts should focus on physical fitness screening, remedial physical training (or discharge for unfit recruits), and continued inclusion of anaerobic running sessions to offset decreased weekly running distance. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Beyond Serial Founder Effects: The Impact of Admixture and Localized Gene Flow on Patterns of Regional Genetic Diversity.

PubMed

Hunley, Keith L; Cabana, Graciela S

2016-07-01

Geneticists have argued that the linear decay in within-population genetic diversity with increasing geographic distance from East Africa is best explained by a phylogenetic process of repeated founder effects, growth, and isolation. However, this serial founder effect (SFE) process has not yet been adequately vetted against other evolutionary processes that may also affect geospatial patterns of diversity. Additionally, studies of the SFE process have been largely based on a limited 52-population sample. Here, we assess the effects of founder effect, admixture, and localized gene flow processes on patterns of global and regional diversity using a published data set of 645 autosomal microsatellite genotypes from 5,415 individuals in 248 widespread populations. We used a formal tree-fitting approach to explore the role of founder effects. The approach involved fitting global and regional population trees to extant patterns of gene diversity and then systematically examining the deviations in fit. We also informally tested the SFE process using linear models of gene diversity versus waypoint geographic distances from Africa. We tested the role of localized gene flow using partial Mantel correlograms of gene diversity versus geographic distance controlling for the confounding effects of treelike genetic structure. We corroborate previous findings that global patterns of diversity, both within and between populations, are the product of an out-of-Africa SFE process. Within regions, however, diversity within populations is uncorrelated with geographic distance from Africa. Here, patterns of diversity have been largely shaped by recent interregional admixture and secondary range expansions. Our detailed analyses of the pattern of diversity within and between populations reveal that the signatures of different evolutionary processes dominate at different geographic scales. These findings have important implications for recent publications on the biology of race.

The evolution of sex is favoured during adaptation to new environments.

PubMed

Becks, Lutz; Agrawal, Aneil F

2012-01-01

Both theory and experiments have demonstrated that sex can facilitate adaptation, potentially yielding a group-level advantage to sex. However, it is unclear whether this process can help solve the more difficult problem of the maintenance of sex within populations. Using experimental populations of the facultatively sexual rotifer Brachionus calyciflorus, we show that rates of sex evolve to higher levels during adaptation but then decline as fitness plateaus. To assess the fitness consequences of genetic mixing, we directly compare the fitnesses of sexually and asexually derived genotypes that naturally occur in our experimental populations. Sexually derived genotypes are more fit than asexually derived genotypes when adaptive pressures are strong, but this pattern reverses as the pace of adaptation slows, matching the pattern of evolutionary change in the rate of sex. These fitness assays test the net effect of sex but cannot be used to disentangle whether selection on sex arises because highly sexual lineages become associated with different allele combinations or with different allele frequencies than less sexual lineages (i.e., "short-" or "long-term" effects, respectively). We infer which of these mechanisms provides an advantage to sex by performing additional manipulations to obtain fitness distributions of sexual and asexual progeny arrays from unbiased parents (rather than from naturally occurring, and thereby evolutionarily biased, parents). We find evidence that sex breaks down adaptive gene combinations, resulting in lower average fitness of sexual progeny (i.e., a short-term disadvantage to sex). As predicted by theory, the advantage to sex arises because sexually derived progeny are more variable in fitness, allowing for faster adaptation. This "long-term advantage" builds over multiple generations, eventually resulting in higher fitness of sexual types.

The Evolution of Sex Is Favoured During Adaptation to New Environments

PubMed Central

Becks, Lutz; Agrawal, Aneil F.

2012-01-01

Both theory and experiments have demonstrated that sex can facilitate adaptation, potentially yielding a group-level advantage to sex. However, it is unclear whether this process can help solve the more difficult problem of the maintenance of sex within populations. Using experimental populations of the facultatively sexual rotifer Brachionus calyciflorus, we show that rates of sex evolve to higher levels during adaptation but then decline as fitness plateaus. To assess the fitness consequences of genetic mixing, we directly compare the fitnesses of sexually and asexually derived genotypes that naturally occur in our experimental populations. Sexually derived genotypes are more fit than asexually derived genotypes when adaptive pressures are strong, but this pattern reverses as the pace of adaptation slows, matching the pattern of evolutionary change in the rate of sex. These fitness assays test the net effect of sex but cannot be used to disentangle whether selection on sex arises because highly sexual lineages become associated with different allele combinations or with different allele frequencies than less sexual lineages (i.e., “short-” or “long-term” effects, respectively). We infer which of these mechanisms provides an advantage to sex by performing additional manipulations to obtain fitness distributions of sexual and asexual progeny arrays from unbiased parents (rather than from naturally occurring, and thereby evolutionarily biased, parents). We find evidence that sex breaks down adaptive gene combinations, resulting in lower average fitness of sexual progeny (i.e., a short-term disadvantage to sex). As predicted by theory, the advantage to sex arises because sexually derived progeny are more variable in fitness, allowing for faster adaptation. This “long-term advantage” builds over multiple generations, eventually resulting in higher fitness of sexual types. PMID:22563299

The Kunming CalFit study: modeling dietary behavioral patterns using smartphone data.

PubMed

Seto, Edmund; Hua, Jenna; Wu, Lemuel; Bestick, Aaron; Shia, Victor; Eom, Sue; Han, Jay; Wang, May; Li, Yan

2014-01-01

Human behavioral interventions aimed at improving health can benefit from objective wearable sensor data and mathematical models. Smartphone-based sensing is particularly practical for monitoring behavioral patterns because smartphones are fairly common, are carried by individuals throughout their daily lives, offer a variety of sensing modalities, and can facilitate various forms of user feedback for intervention studies. We describe our findings from a smartphone-based study, in which an Android-based application we developed called CalFit was used to collect information related to young adults' dietary behaviors. In addition to monitoring dietary patterns, we were interested in understanding contextual factors related to when and where an individual eats, as well as how their dietary intake relates to physical activity (which creates energy demand) and psychosocial stress. 12 participants were asked to use CalFit to record videos of their meals over two 1-week periods, which were translated into nutrient intake by trained dietitians. During this same period, triaxial accelerometry was used to assess each subject's energy expenditure, and GPS was used to record time-location patterns. Ecological momentary assessment was also used to prompt subjects to respond to questions on their phone about their psychological state. The GPS data were processed through a web service we developed called Foodscoremap that is based on the Google Places API to characterize food environments that subjects were exposed to, which may explain and influence dietary patterns. Furthermore, we describe a modeling framework that incorporates all of these information to dynamically infer behavioral patterns that may be used for future intervention studies.

Low Dose Aerosol Fitness at the Innate Phase of Murine Infection Better Predicts Virulence amongst Clinical Strains of Mycobacterium tuberculosis

PubMed Central

Caceres, Neus; Llopis, Isaac; Marzo, Elena; Prats, Clara; Vilaplana, Cristina; de Viedma, Dario Garcia; Samper, Sofía; Lopez, Daniel; Cardona, Pere-Joan

2012-01-01

Background Evaluation of a quick and easy model to determine the intrinsic ability of clinical strains to generate active TB has been set by assuming that this is linked to the fitness of Mycobacterium tuberculosis strain at the innate phase of the infection. Thus, the higher the bacillary load, the greater the possibility of inducting liquefaction, and thus active TB, once the adaptive response is set. Methodology/Principal Findings The virulence of seven clinical Mycobacterium tuberculosis strains isolated in Spain was tested by determining the bacillary concentration in the spleen and lung of mice at weeks 0, 1 and 2 after intravenous (IV) inoculation of 104 CFU, and by determining the growth in vitro until the stationary phase had been reached. Cord distribution automated analysis showed two clear patterns related to the high and low fitness in the lung after IV infection. This pattern was not seen in the in vitro fitness tests, which clearly favored the reference strain (H37Rv). Subsequent determination using a more physiological low-dose aerosol (AER) inoculation with 102 CFU showed a third pattern in which the three best values coincided with the highest dissemination capacity according to epidemiological data. Conclusions/Significance The fitness obtained after low dose aerosol administration in the presence of the innate immune response is the most predictive factor for determining the virulence of clinical strains. This gives support to a mechanism of the induction of active TB derived from the dynamic hypothesis of latent tuberculosis infection. PMID:22235258

Near surface bulk density estimates of NEAs from radar observations and permittivity measurements of powdered geologic material

NASA Astrophysics Data System (ADS)

Hickson, Dylan; Boivin, Alexandre; Daly, Michael G.; Ghent, Rebecca; Nolan, Michael C.; Tait, Kimberly; Cunje, Alister; Tsai, Chun An

2018-05-01

The variations in near-surface properties and regolith structure of asteroids are currently not well constrained by remote sensing techniques. Radar is a useful tool for such determinations of Near-Earth Asteroids (NEAs) as the power of the reflected signal from the surface is dependent on the bulk density, ρbd, and dielectric permittivity. In this study, high precision complex permittivity measurements of powdered aluminum oxide and dunite samples are used to characterize the change in the real part of the permittivity with the bulk density of the sample. In this work, we use silica aerogel for the first time to increase the void space in the samples (and decrease the bulk density) without significantly altering the electrical properties. We fit various mixing equations to the experimental results. The Looyenga-Landau-Lifshitz mixing formula has the best fit and the Lichtenecker mixing formula, which is typically used to approximate planetary regolith, does not model the results well. We find that the Looyenga-Landau-Lifshitz formula adequately matches Lunar regolith permittivity measurements, and we incorporate it into an existing model for obtaining asteroid regolith bulk density from radar returns which is then used to estimate the bulk density in the near surface of NEA's (101955) Bennu and (25143) Itokawa. Constraints on the material properties appropriate for either asteroid give average estimates of ρbd = 1.27 ± 0.33g/cm3 for Bennu and ρbd = 1.68 ± 0.53g/cm3 for Itokawa. We conclude that our data suggest that the Looyenga-Landau-Lifshitz mixing model, in tandem with an appropriate radar scattering model, is the best method for estimating bulk densities of regoliths from radar observations of airless bodies.

Structural, microstructural and electrical characterization of BaSnO3 and Ba0.90Y0.10SnO3 synthesized by solution combustion method

NASA Astrophysics Data System (ADS)

Kumar, Upendra; Yadav, Dharmendra; Upadhyay, Shail; Thakur, Anukul K.

2018-04-01

Powder of perovskite oxides BaSnO3 and Ba0.90Y0.10SnO3 have been synthesized by solution combustion method. Rietveld profile analysis shows that the phases crystallize with cubic unit cell in the space group pm3m. Further purity of the synthesized powders was checked by Fourier transform of infrared (FTIR) spectroscopy. The average grain size of the sintered samples was obtained using Scanning electron microscopy (SEM) and found to be 4.9 and 2.8 1m for BaSnO3 and Ba0.90Y0.10SnO3, respectively. The AC conductivity (σac) of synthesized samples was measured in the frequency range from 24Hz-1MHz and temperature range 100 - 600°C. Conductivity spectra of both the samples followed universal Johnscher's power law at different temperatures. The value of bulk or dc conductivity (σdc) at different temperatures has been extracted by fitting the Johnscher's power law to AC conductivity spectra. The activation energy for σc has been obtained from the least square linear fit of data points and found to be 0.53 eV and 0.43 eV, respectively for BaSnO3 and Ba0.90Y0.10SnO3. Based on the value of activation energy it is proposed that conduction in these samples is govern via hopping of (OH)•. The value of conductivity at temperature 550°C of Ba0.90Y0.10SnO3 is 0.00406 S-cm-1 higher than BaSnO3 (0.00173 S-cm-1) at the same temperature.

Adsorption of methyl orange from aqueous solution by aminated pumpkin seed powder: Kinetics, isotherms, and thermodynamic studies.

PubMed

Subbaiah, Munagapati Venkata; Kim, Dong-Su

2016-06-01

Present research discussed the utilization of aminated pumpkin seed powder (APSP) as an adsorbent for methyl orange (MO) removal from aqueous solution. Batch sorption experiments were carried to evaluate the influence of pH, initial dye concentration, contact time, and temperature. The APSP was characterized by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The experimental equilibrium adsorption data were fitted using two two-parameter models (Langmuir and Freundlich) and two three-parameter models (Sips and Toth). Langmuir and Sips isotherms provided the best model for MO adsorption data. The maximum monolayer sorption capacity was found to be 200.3mg/g based on the Langmuir isotherm model. The pseudo-first-order and pseudo-second-order model equations were used to analyze the kinetic data of the adsorption process and the data was fitted well with the pseudo-second-order kinetic model (R(2)>0.97). The calculated thermodynamic parameters such as ΔG(0), ΔH(0) and ΔS(0) from experimental data showed that the sorption of MO onto APSP was feasible, spontaneous and endothermic in the temperature range 298-318 K. The FTIR results revealed that amine and carboxyl functional groups present on the surface of APSP. The SEM results show that APSP has an irregular and porous surface which is adequate morphology for dye adsorption. Desorption experiments were carried to explore the feasibility of adsorbent regeneration and the adsorbed MO from APSP was desorbed using 0.1M NaOH with an efficiency of 93.5%. Findings of the present study indicated that APSP can be successfully used for removal of MO from aqueous solution. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of desiccation tolerance among Listeria monocytogenes, Escherichia coli O157:H7, Salmonella enterica, and Cronobacter sakazakii in powdered infant formula.

PubMed

Koseki, Shigenobu; Nakamura, Nobutaka; Shiina, Takeo

2015-01-01

Bacterial pathogens such as Listeria monocytogenes, Escherichia coli O157:H7, Salmonella enterica, and Cronobacter sakazakii have demonstrated long-term survival in/on dry or low-water activity (aw) foods. However, there have been few comparative studies on the desiccation tolerance among these bacterial pathogens separately in a same food matrix. In the present study, the survival kinetics of the four bacterial pathogens separately inoculated onto powdered infant formula as a model low-aw food was compared during storage at 5, 22, and 35°C. No significant differences in the survival kinetics between E. coli O157:H7 and L. monocytogenes were observed. Salmonella showed significantly higher desiccation tolerance than these pathogens, and C. sakazakii demonstrated significantly higher desiccation tolerance than all other three bacteria studied. Thus, the desiccation tolerance was represented as C. sakazakii > Salmonella > E. coli O157:H7 = L. monocytogenes. The survival kinetics of each bacterium was mathematically analyzed, and the observed kinetics was successfully described using the Weibull model. To evaluate the variability of the inactivation kinetics of the tested bacterial pathogens, the Monte Carlo simulation was performed using assumed probability distribution of the estimated fitted parameters. The simulation results showed that the storage temperature significantly influenced survival of each bacterium under the dry environment, where the bacterial inactivation became faster with increasing storage temperature. Furthermore, the fitted rate and shape parameters of the Weibull model were successfully modelled as a function of temperature. The numerical simulation of the bacterial inactivation was realized using the functions of the parameters under arbitrary fluctuating temperature conditions.

Contrasting Patterns in Mammal–Bacteria Coevolution: Bartonella and Leptospira in Bats and Rodents

PubMed Central

Lei, Bonnie R.; Olival, Kevin J.

2014-01-01

Background Emerging bacterial zoonoses in bats and rodents remain relatively understudied. We conduct the first comparative host–pathogen coevolutionary analyses of bacterial pathogens in these hosts, using Bartonella spp. and Leptospira spp. as a model. Methodology/Principal Findings We used published genetic data for 51 Bartonella genotypes from 24 bat species, 129 Bartonella from 38 rodents, and 26 Leptospira from 20 bats. We generated maximum likelihood and Bayesian phylogenies for hosts and bacteria, and tested for coevoutionary congruence using programs ParaFit, PACO, and Jane. Bartonella spp. and their bat hosts had a significant coevolutionary fit (ParaFitGlobal = 1.9703, P≤0.001; m2 global value = 7.3320, P≤0.0001). Bartonella spp. and rodent hosts also indicated strong overall patterns of cospeciation (ParaFitGlobal = 102.4409, P≤0.001; m2 global value = 86.532, P≤0.0001). In contrast, we were unable to reject independence of speciation events in Leptospira and bats (ParaFitGlobal = 0.0042, P = 0.84; m2 global value = 4.6310, P = 0.5629). Separate analyses of New World and Old World data subsets yielded results congruent with analysis from entire datasets. We also conducted event-based cophylogeny analyses to reconstruct likely evolutionary histories for each group of pathogens and hosts. Leptospira and bats had the greatest number of host switches per parasite (0.731), while Bartonella and rodents had the fewest (0.264). Conclusions/Significance In both bat and rodent hosts, Bartonella exhibits significant coevolution with minimal host switching, while Leptospira in bats lacks evolutionary congruence with its host and has high number of host switches. Reasons underlying these variable coevolutionary patterns in host range are likely due to differences in disease-specific transmission and host ecology. Understanding the coevolutionary patterns and frequency of host-switching events between bacterial pathogens and their hosts will allow better prediction of spillover between mammal reservoirs, and ultimately to humans. PMID:24651646

Type A Behaviors, Hostility, Anger and Exercise Adherence.

ERIC Educational Resources Information Center

Goffaux, Jacqueline; And Others

A study was conducted to examine the relationship between the components of the Type A behavior pattern and the maintenance of exercise participation in a 5-month physical fitness program. Metropolitan Government employees (N=200) volunteered to participate in a pilot health promotion program. Physical fitness activities (supervised walking,…

A Proposed Conceptual Framework for Curriculum Design in Physical Fitness.

ERIC Educational Resources Information Center

Miller, Peter V.; Beauchamp, Larry S.

A physical fitness curriculum, designed to provide cumulative benefits in a sequential pattern, is based upon a framework of a conceptual structure. The curriculum's ultimate goal is the achievement of greater physiological efficiency through a holistic approach that would strengthen circulatory-respiratory, mechanical, and neuro-muscular…

Pattern of Change in Prolonged Exposure and Cognitive-Processing Therapy for Female Rape Victims With Posttraumatic Stress Disorder

PubMed Central

Nishith, Pallavi; Resick, Patricia A.; Griffin, Michael G.

2010-01-01

Curve estimation techniques were used to identify the pattern of therapeutic change in female rape victims with posttraumatic stress disorder (PTSD). Within-session data on the Posttraumatic Stress Disorder Symptom Scale were obtained, in alternate therapy sessions, on 171 women. The final sample of treatment completers included 54 prolonged exposure (PE) and 54 cognitive-processing therapy (CPT) completers. For both PE and CPT, a quadratic function provided the best fit for the total PTSD, reexperiencing, and arousal scores. However, a difference in the line of best fit was observed for the avoidance symptoms. Although a quadratic function still provided a better fit for the PE avoidance, a linear function was more parsimonious in explaining the CPT avoidance variance. Implications of the findings are discussed. PMID:12182271

Modification of Pseudobrookite Fe2-XMnxTiO5 with Solid State Reaction Method using a Mechanical Milling

NASA Astrophysics Data System (ADS)

Sarwanto, Y.; Adi, W. A.

2017-05-01

Modification of pseudobrookite Fe2-xMnxTiO5 with solid state reaction method using a mechanical milling has been synthesized. Raw materials used to prepare these samples were Fe2O3, MnCO3, and TiO2. Fe2O3 and TiO2 powders (ratio of 1:1) were mixed with MnCO3 powder at various composition of x = 0; 0.1; 0.2; 0.3; 0.4; 0.5; and 1, which each composition was added with 50 ml ethanol and then milled for 5 hours through high energy milling, after that sintered at 1000 °C for 5 hours by using box furnace. The phases of Fe2-xMnxTiO5 were measured by using X-ray diffraction (XRD) and then identified by using Match program. The crystal structure was analyzed by using the program of General Structure Analysis System (GSAS). Quality fitting of Rwp and χ2 (chi-squared) are relatively good because based on the curve of normalized error distribution looks just left background and its normal probability plot shows the value of comparable between observation and expectation. The refinement analyses of X-ray diffraction patterns showed that the samples formed single phase for x ≤ 0.3. However, the samples of x > 0.3 were multi-phases. The single phase of sample had composition of pseudobrookite Fe2TiO5 with orthorhombic structure, space group of C m c m (63), the lattice parameters of a = 3.7390 Å, b = 9.7790 Å, and c = 9.9780 Å, α = β = γ = 90°, V = 364.83 Å3, and ρ = 4.360 g.cm-3. Meanwhile, the other phase analysis for the composition of x > 0.3 is bixbyite (FeMnO3). The bixbyite has a cubic structure, under the space group of I a - 3 (206), the lattice parameters of a = b = c = 9.40 Å, α = β = γ = 90°, V = 830.58 Å3, and ρ = 5.078 g.cm-3.

Microorganism Identification Based On MALDI-TOF-MS Fingerprints

NASA Astrophysics Data System (ADS)

Elssner, Thomas; Kostrzewa, Markus; Maier, Thomas; Kruppa, Gary

Advances in MALDI-TOF mass spectrometry have enabled the ­development of a rapid, accurate and specific method for the identification of bacteria directly from colonies picked from culture plates, which we have named the MALDI Biotyper. The picked colonies are placed on a target plate, a drop of matrix solution is added, and a pattern of protein molecular weights and intensities, "the protein fingerprint" of the bacteria, is produced by the MALDI-TOF mass spectrometer. The obtained protein mass fingerprint representing a molecular signature of the microorganism is then matched against a database containing a library of previously measured protein mass fingerprints, and scores for the match to every library entry are produced. An ID is obtained if a score is returned over a pre-set threshold. The sensitivity of the techniques is such that only approximately 104 bacterial cells are needed, meaning that an overnight culture is sufficient, and the results are obtained in minutes after culture. The improvement in time to result over biochemical methods, and the capability to perform a non-targeted identification of bacteria and spores, potentially makes this method suitable for use in the detect-to-treat timeframe in a bioterrorism event. In the case of white-powder samples, the infectious spore is present in sufficient quantity in the powder so that the MALDI Biotyper result can be obtained directly from the white powder, without the need for culture. While spores produce very different patterns from the vegetative colonies of the corresponding bacteria, this problem is overcome by simply including protein fingerprints of the spores in the library. Results on spores can be returned within minutes, making the method suitable for use in the "detect-to-protect" timeframe.

Atlantoaxial dislocation in a patient with nonsyndromic symmetrical dwarfism: Report of a rare case

PubMed Central

Ram, Duvuru; Madhugiri, Venkatesh S.; Roopesh Kumar, V. R.; Gulati, Reena; Sasidharan, Gopalakrishnan M.; Gundamaneni, Sudheer Kumar

2015-01-01

Congenital anomalies of the craniovertebral junction (CVJ) are complex developmental defects. We describe a patient with atlantoaxial dislocation (AAD) and short stature whose morphopathologydid not fit into any of the previously described syndromic constellations. The patient underwent a reduction of the AAD followed by fixation with C1-C2 transarticular screws. Although numerous syndromes have been linked to both dwarfism and craniovertebral junction anomalies, this patient did not fit into any of these patterns. It is possible that this may be one of the many as yet unrecognized patterns of congenital anomalies. PMID:25788820

Comparability of item quality indices from sparse data matrices with random and non-random missing data patterns.

PubMed

Wolfe, Edward W; McGill, Michael T

2011-01-01

This article summarizes a simulation study of the performance of five item quality indicators (the weighted and unweighted versions of the mean square and standardized mean square fit indices and the point-measure correlation) under conditions of relatively high and low amounts of missing data under both random and conditional patterns of missing data for testing contexts such as those encountered in operational administrations of a computerized adaptive certification or licensure examination. The results suggest that weighted fit indices, particularly the standardized mean square index, and the point-measure correlation provide the most consistent information between random and conditional missing data patterns and that these indices perform more comparably for items near the passing score than for items with extreme difficulty values.

Precision of Fit of Titanium and Cast Implant Frameworks Using a New Matching Formula

PubMed Central

Sierraalta, Marianella; Vivas, Jose L.; Razzoog, Michael E.; Wang, Rui-Feng

2012-01-01

Statement of the Problem. Fit of prosthodontic frameworks is linked to the lifetime survival of dental implants and maintenance of surrounding bone. Purpose. The purpose of this study was to evaluate and compare the precision of fit of milled one-piece Titanium fixed complete denture frameworks to that of conventional cast frameworks. Material and Methods. Fifteen casts fabricated from a single edentulous CAD/CAM surgical guide were separated in two groups and resin patterns simulating the framework for a fixed complete denture developed. Five casts were sent to dental laboratories to invest, cast in a Palladium-Gold alloy and fit the framework. Ten casts had the resin pattern scanned for fabrication of milled bars in Titanium. Using measuring software, positions of implant replicas in the definitive model were recorded. The three dimensional spatial orientation of each implant replica was matched to the implant replica. Results. Results demonstrated the mean vertical gap of the Cast framework was 0.021 (+0.004) mm and 0.012 (0.002) mm determined by fixed and unfixed best-fit matching coordinate system. For Titanium frameworks they were 0.0037 (+0.0028) mm and 0.0024 (+0.0005) mm, respectively. Conclusions. Milled one-piece Titanium fixed complete denture frameworks provided a more accurate precision of fit then traditional cast frameworks. PMID:22550486

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).

Patterns and Predictors of Language and Literacy Abilities 4-10 Years in the Longitudinal Study of Australian Children.

PubMed

Zubrick, Stephen R; Taylor, Catherine L; Christensen, Daniel

2015-01-01

Oral language is the foundation of literacy. Naturally, policies and practices to promote children's literacy begin in early childhood and have a strong focus on developing children's oral language, especially for children with known risk factors for low language ability. The underlying assumption is that children's progress along the oral to literate continuum is stable and predictable, such that low language ability foretells low literacy ability. This study investigated patterns and predictors of children's oral language and literacy abilities at 4, 6, 8 and 10 years. The study sample comprised 2,316 to 2,792 children from the first nationally representative Longitudinal Study of Australian Children (LSAC). Six developmental patterns were observed, a stable middle-high pattern, a stable low pattern, an improving pattern, a declining pattern, a fluctuating low pattern, and a fluctuating middle-high pattern. Most children (69%) fit a stable middle-high pattern. By contrast, less than 1% of children fit a stable low pattern. These results challenged the view that children's progress along the oral to literate continuum is stable and predictable. Multivariate logistic regression was used to investigate risks for low literacy ability at 10 years and sensitivity-specificity analysis was used to examine the predictive utility of the multivariate model. Predictors were modelled as risk variables with the lowest level of risk as the reference category. In the multivariate model, substantial risks for low literacy ability at 10 years, in order of descending magnitude, were: low school readiness, Aboriginal and/or Torres Strait Islander status and low language ability at 8 years. Moderate risks were high temperamental reactivity, low language ability at 4 years, and low language ability at 6 years. The following risk factors were not statistically significant in the multivariate model: Low maternal consistency, low family income, health care card, child not read to at home, maternal smoking, maternal education, family structure, temperamental persistence, and socio-economic area disadvantage. The results of the sensitivity-specificity analysis showed that a well-fitted multivariate model featuring risks of substantive magnitude did not do particularly well in predicting low literacy ability at 10 years.

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.

Phase diagram of the relaxor ferroelectric (1- x )Pb(Mg 1/3Nb 2/3)O 3+ x PbTiO 3 revisited: a neutron powder diffraction study of the relaxor skin effect

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

Phelan, D.; Rodriguez, E. E.; Gao, J.

2014-11-17

We revisit the phase diagram of the relaxor ferroelectric PMN- xPT using neutron powder diffraction to test suggestions that residual oxygen vacancies and/or strain affect the ground state crystal structure. Powdered samples of PMN- xPT were prepared with nominal compositions of x = 0:10, 0.20, 0.30, and 0.40 and divided into two identical sets, one of which was annealed in air to relieve grinding-induced strain and to promote an ideal oxygen stoichiometry. For a given composition and temperature the same structural phase is observed for each specimen. However, the distortions in all of the annealed samples are smaller than thosemore » in the as-grown samples. Further, the diffraction patterns for x = 0:10, 0.20, and 0.30 are best refined using the monoclinic Cm space group. By comparing our neutron diffraction results to those obtained on single crystals having similar compositions, we conclude that the relaxor skin effect in PMN- xPT vanishes on the Ti-rich side of the morphotropic phase boundary.« less

Low-Cost Chemical-Responsive Adhesive Sensing Chips.

PubMed

Tan, Weirui; Zhang, Liyuan; Shen, Wei

2017-12-06

Chemical-responsive adhesive sensing chip is a new low-cost analytical platform that uses adhesive tape loaded with indicator reagents to detect or quantify the target analytes by directly sticking the tape to the samples of interest. The chemical-responsive adhesive sensing chips can be used with paper to analyze aqueous samples; they can also be used to detect and quantify solid, particulate, and powder analytes. The colorimetric indicators become immediately visible as the contact between the functionalized adhesives and target samples is made. The chemical-responsive adhesive sensing chip expands the capability of paper-based analytical devices to analyze solid, particulate, or powder materials via one-step operation. It is also a simpler alternative way, to the covalent chemical modification of paper, to eliminate indicator leaching from the dipstick-style paper sensors. Chemical-responsive adhesive chips can display analytical results in the form of colorimetric dot patterns, symbols, and texts, enabling clear understanding of assay results by even nonprofessional users. In this work, we demonstrate the analyses of heavy metal salts in silica powder matrix, heavy metal ions in water, and bovine serum albumin in an aqueous solution. The detection is one-step, specific, sensitive, and easy-to-operate.

Effects of Heat-Treatment Temperature on the Microstructure, Electrical and Dielectric Properties of M-Type Hexaferrites

NASA Astrophysics Data System (ADS)

Ali, Ihsan; Islam, M. U.; Awan, M. S.; Ahmad, Mukhtar

2014-02-01

M-type hexaferrite BaCr x Ga x Fe12-2 x O19 ( x = 0.2) powders have been synthesized by use of a sol-gel autocombustion method. The powder samples were pressed into 12-mm-diameter pellets by cold isostatic pressing at 2000 bar then heat treated at 700°C, 800°C, 900°C, and 1000°C. X-ray diffraction patterns of the powder sample heat treated at 1000°C confirmed formation of the pure M-type hexaferrite phase. The electrical resistivity at room temperature was significantly enhanced by increasing the temperature of heat treatment and approached 5.84 × 109 Ω cm for the sample heat treated at 1000°C. Dielectric constant and dielectric loss tangent decreased whereas conductivity increased with increasing applied field frequency in the range 1 MHz-3 GHz. The dielectric properties and ac conductivity were explained on the basis of space charge polarization in accordance with the Maxwell-Wagner two-layer model and Koop's phenomenological theory. The single-phase synthesized materials may be useful for high-frequency applications, for example reduction of eddy current losses and radar absorbing waves.

Crystal structure of rivastigmine hydrogen tartrate Form I (Exelon®), C 14H 23N 2O 2(C 4H 5O 6)

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

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

2016-03-08

The crystal structure of rivastigmine hydrogen tartrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Rivastigmine hydrogen tartrate crystallizes in space groupP2 1(#4) witha= 17.538 34(5),b= 8.326 89(2),c= 7.261 11(2) Å,β= 98.7999(2)°,V= 1047.929(4) Å 3, andZ= 2. The un-ionized end of the hydrogen tartrate anions forms a very strong hydrogen bond with the ionized end of another anion to form a chain. The ammonium group of the rivastigmine cation forms a strong discrete hydrogen bond with the carbonyl oxygen atom of the un-ionized end of the tartrate anion. These hydrogen bondsmore » form a corrugated network in thebc-plane. Both hydroxyl groups of the tartrate anion form intramolecular O–H···O hydrogen bonds. Several C–H···O hydrogen bonds appear to contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File ™as entry 00-064-1501.« less

Chemiluminescence measurements on irradiated garlic powder by the single photon counting technique

NASA Astrophysics Data System (ADS)

Narvaiz, P.

1995-02-01

The feasibility of identifying irradiated garlic powder measuring chemiluminescence by liquid scintillation spectrometry was studied. Samples packed in 100 μm thick polyethylene bags were irradiated in a 60Co semi-industrial facility, with doses of 10 and 30 kGy. Control and irradiated samples were stored at 20 ± 4°C and 70 ± 10% RH in darkness for 2 years. Assays were performed to establish the best sample concentration and pH of the buffer solution in which garlic powder was to be suspended for its measurement. The water content of garlic samples was also analyzed throughout storage time, as it related to the stability of the species causing luminescence. Chemiluminescence values diminished in every sample over storage time following an exponential pattern. Irradiated samples showed values significantly higher than those of the control samples, according to the radiation dose, throughout the storage period. This does not necessarily imply that the identification of the irradiated samples would be certain, since values of control samples coming from different origins have been found to fluctuate within a rather wide range. Nonetheless, in principle, the method looks promising for the measurement of chemiluminescence in irradiated samples

Preparation of Functionally Graded Materials (FGMs) Using Coal Fly Ash and NiCr-Based Alloy Powder by Spark Plasma Sintering (SPS)

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

Kaneko, Gen-yo; Kitagawa, Hiroyuki; Hasezaki, Kazuhiro

2008-02-15

Functionally Graded Materials (FGMs) were prepared by spark plasma sintering (SPS) using coal fly ash and NiCr alloy powder. The coal fly ash was produced by the Misumi Coal Thermal Power Station (Chugoku Electric Power Co., Inc.), with 80 wt% nickel and 20 wt% chromium (Fukuda Metal Foil and Powder Co., Ltd.) used as source materials. The sintering temperature in the graphite die was 1000 deg. C. X-ray diffraction patterns of the sintered coal fly ash materials indicated that mullite (3Al{sub 2}O{sub 3}{center_dot}2SiO{sub 2}) and silica (SiO{sub 2}) phases were predominant. Direct joining of coal fly ash and NiCr causesmore » fracture at the interface. This is due to the mismatch in the thermal expansion coefficients (CTE). A crack in the FGM was observed between the two layers with a CTE difference of over 4.86x10{sup -6} K{sup -1}, while a crack in the FGM was difficult to detect when the CTE difference was less than 2.77x10{sup -6} K{sup -1}.« less

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.

Preparation, characterizations and photocatalytic activity of a ZnO/TiO2 nanocomposite

NASA Astrophysics Data System (ADS)

Lachom, Vichuda; Poolcharuansin, Phitsanu; Laokul, Paveena

2017-03-01

Nanoparticles of TiO2, ZnO and nanocomposite ZnO/TiO2 were prepared via a co-precipitation method. The precursor powders were calcined in air at 400 and 500 °C for 2 h. Crystallite sizes of the calcined samples ranged from 11-43 nm. The XRD patterns of ZnO/TiO2 powder showed two phases of anatase and wurtzite, with no ZnTiO3 impurity phase. TEM images showed three types of particles in the ZnO/TiO2 samples: a fine particle type of TiO2 and submicron ellipsoidal and rod-like particles of ZnO. The energy gap (E g) of the calcined powders was evaluated using UV-vis absorption spectra and found to be in the range of 3.15-3.60 eV. Photodegradation efficiencies of the prepared samples in methyl orange aqueous solution were investigated under UVA irradiation. The results showed that nanocomposite ZnO/TiO2 calcined at 400 °C exhibited the highest apparent rate constant (k), and a higher capacity for methyl orange removal than TiO2 and ZnO nanoparticles.

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

High temperature phase stability in Li{sub 0.12}Na{sub 0.88}NbO{sub 3}: A combined powder X-ray and neutron diffraction study

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

Mishra, S. K.; Krishna, P. S. R.; Shinde, A. B.

2015-09-07

The phase stabilities of ecofriendly piezoelectric material of lithium doped sodium niobate for composition Li{sub 0.12}Na{sub 0.88}NbO{sub 3} (LNN12) have been investigated by a combination of powder X-ray and neutron diffraction techniques in the temperature range of 300–1100 K. We observed interesting changes with appearance or disappearance of the super-lattice reflections in the powder diffraction patterns. Unambiguous experimental evidence is shown for coexistence of paraelectric and ferroelectric orthorhombic phases in the temperature range of 525 K to 675 K. We identified the correct crystal structure of LNN12 with temperature and correlated it with observed anomaly in the physical properties. Identification of crystal structuremore » also helps in the mode assignments in Raman and infrared spectroscopies. We argued that application of chemical pressure as a result of Li substitution in NaNbO{sub 3} matrix favors the freezing of zone centre phonons in contrast to the freezing of zone boundary phonons in pure NaNbO{sub 3} with the variation of temperature.« less

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.

Oxygen ion-conducting dense ceramic

DOEpatents

Balachandran, Uthamalingam; Kleefisch, Mark S.; Kobylinski, Thaddeus P.; Morissette, Sherry L.; Pei, Shiyou

1998-01-01

Preparation, structure, and properties of mixed metal oxide compositions and their uses are described. Mixed metal oxide compositions of the invention have stratified crystalline structure identifiable by means of powder X-ray diffraction patterns. In the form of dense ceramic membranes, the present compositions demonstrate an ability to separate oxygen selectively from a gaseous mixture containing oxygen and one or more other volatile components by means of ionic conductivities.

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.

Measurement of 13C chemical shift tensor principal values with a magic-angle turning experiment.

PubMed

Hu, J Z; Orendt, A M; Alderman, D W; Pugmire, R J; Ye, C; Grant, D M

1994-08-01

The magic-angle turning (MAT) experiment introduced by Gan is developed into a powerful and routine method for measuring the principal values of 13C chemical shift tensors in powdered solids. A large-volume MAT probe with stable rotation frequencies down to 22 Hz is described. A triple-echo MAT pulse sequence is introduced to improve the quality of the two-dimensional baseplane. It is shown that measurements of the principal values of chemical shift tensors in complex compounds can be enhanced by using either short contact times or dipolar dephasing pulse sequences to isolate the powder patterns from protonated or non-protonated carbons, respectively. A model compound, 1,2,3-trimethoxybenzene, is used to demonstrate these techniques, and the 13C principal values in 2,3-dimethylnaphthalene and Pocahontas coal are reported as typical examples.

Magnetic and magnetocaloric properties of spin-glass material DyNi 0.67Si 1.34

DOE PAGES

Chen, X.; Mudryk, Y.; Pathak, A. K.; ...

2017-04-18

Structural, magnetic, and magnetocaloric properties of DyNi 0.67Si 1.34 were investigated using X-ray powder diffraction, magnetic susceptibility, and magnetization measurements. X-ray powder diffraction pattern shows that DyNi 0.67Si 1.34 crystallizes in the AlB 2-type hexagonal structure (space group: P6/ mmm, No. 191, a = b = 3.9873(9) Å, and c = 3.9733(1) Å). The compound is a spin-glass with the freezing temperature TG = 6.2 K. The ac magnetic susceptibility measurements confirm magnetic frustration in DyNi 0.67Si 1.34. Furthermore, the maximum value of the magnetic entropy change determined from M(H) data is –16.1 J/kg K at 10.5 K for amore » field change of 70 kOe.« less

Thermal, spectroscopic and structural characterization of isostructural phase transition in 4-hydroxybenzaldehyde

NASA Astrophysics Data System (ADS)

Panicker, Lata

2018-05-01

Polycrystalline samples of 4-hydroxybenzaldehyde (4-HOBAL) were investigated using differential scanning calorimeter (DSC), Raman spectroscopy and X-ray powder diffraction. The DSC data indicated that 4-HOBAL on heating undergoes a polymorphic transformation from polymorph I to polymorph II. The polymorph II formed remains metastable at ambient condition and transforms to polymorph I when annealed at ambient temperature for more than seven days. The structural information of polymorphs I and II obtained using its X-ray powder diffraction patterns indicated that 4-HOBAL undergoes an isostructural phase transition from polymorph I (monoclinic, P21/c) to polymorph II (monoclinic, P21/c). Raman data suggest that this structural change is associated with some change in its molecular interactions. Thus, in 4-HOBAL the polymorphic phase transformation (II to I) even though energetically favoured is kinetically hindered.

Aberrant Learning Achievement Detection Based on Person-Fit Statistics in Personalized e-Learning Systems

ERIC Educational Resources Information Center

Liu, Ming-Tsung; Yu, Pao-Ta

2011-01-01

A personalized e-learning service provides learning content to fit learners' individual differences. Learning achievements are influenced by cognitive as well as non-cognitive factors such as mood, motivation, interest, and personal styles. This paper proposes the Learning Caution Indexes (LCI) to detect aberrant learning patterns. The philosophy…

Fitbit and Fitabase Technology: Tracking and Evaluating Youth Physical Activity

ERIC Educational Resources Information Center

Franzen-Castle, Lisa; Dunker, Tara; Chai, Weiwen; Krehbiel, Michelle

2017-01-01

With the health of today's youth a national priority, professionals need tools for accurately assessing activity patterns and motivating behavior change. Fitness technology may be a promising tool for promoting positive behavior change. The afterschool program WeCook: Fun with Food and Fitness focused on improving food preparation skills,…

Accumulating Brisk Walking for Fitness, Cardiovascular Risk, and Psychological Health.

ERIC Educational Resources Information Center

Murphy, Marie; Nevill, Alan; Neville, Charlotte; Biddle, Stuart; Hardman, Adrianne

2002-01-01

Compared the effects of different patterns of regular brisk walking on fitness, cardiovascular disease risk factors, and psychological well-being in previously sedentary adults. Data on adults who completed either short-bout or long-bout walking programs found that three short bouts of brisk walking accumulated throughout the day were as effective…

Water Fit to Drink.

ERIC Educational Resources Information Center

Donovan, Edward P.

The major objective of this module is to help students understand how water from a source such as a lake is treated to make it fit to drink. The module, consisting of five major activities and a test, is patterned after Individualized Science Instructional System (ISIS) modules. The first activity (Planning) consists of a brief introduction and a…

Sexual dimorphism is associated with population fitness in the seed beetle Callosobruchus maculatus.

PubMed

Rankin, Daniel J; Arnqvist, Göran

2008-03-01

The population consequences of sexual selection remain empirically unexplored. Comparative studies, involving extinction risk, have yielded different results as to the effect of sexual selection on population densities make contrasting predictions. Here, we investigate the relationship between sexual dimorphism (SD) and population productivity in the seed beetle Callosobruchus maculatus, using 13 populations that have evolved in isolation. Geometric morphometric methods and image analysis are employed to form integrative measures of sexual dimorphism, composed of variation in weight, size, body shape, and pigmentation. We found a positive relationship between SD and adult fitness (net adult offspring production) across our study populations, but failed to find any association between SD and juvenile fitness (egg-to-adult survival). Several mechanisms may have contributed to the pattern found, and variance in sexual selection regimes across populations, either in female choice for "good genes" or in the magnitude of direct benefits provided by their mates, would tend to produce the pattern seen. However, our results suggest that evolutionary constraints in the form of intralocus sexual conflict may have been the major generator of the relationship seen between SD and population fitness.

Detection and validation of unscalable item score patterns using item response theory: an illustration with Harter's Self-Perception Profile for Children.

PubMed

Meijer, Rob R; Egberink, Iris J L; Emons, Wilco H M; Sijtsma, Klaas

2008-05-01

We illustrate the usefulness of person-fit methodology for personality assessment. For this purpose, we use person-fit methods from item response theory. First, we give a nontechnical introduction to existing person-fit statistics. Second, we analyze data from Harter's (1985) Self-Perception Profile for Children (Harter, 1985) in a sample of children ranging from 8 to 12 years of age (N = 611) and argue that for some children, the scale scores should be interpreted with care and caution. Combined information from person-fit indexes and from observation, interviews, and self-concept theory showed that similar score profiles may have a different interpretation. For some children in the sample, item scores did not adequately reflect their trait level. Based on teacher interviews, this was found to be due most likely to a less developed self-concept and/or problems understanding the meaning of the questions. We recommend investigating the scalability of score patterns when using self-report inventories to help the researcher interpret respondents' behavior correctly.

The rule of declining adaptability in microbial evolution experiments

PubMed Central

Couce, Alejandro; Tenaillon, Olivier A.

2015-01-01

One of the most recurrent observations after two decades of microbial evolution experiments regards the dynamics of fitness change. In a given environment, low-fitness genotypes are recurrently observed to adapt faster than their more fit counterparts. Since adaptation is the main macroscopic outcome of Darwinian evolution, studying its patterns of change could potentially provide insight into key issues of evolutionary theory, from fixation dynamics to the genetic architecture of organisms. Here, we re-analyze several published datasets from experimental evolution with microbes and show that, despite large differences in the origin of the data, a pattern of inverse dependence of adaptability with fitness clearly emerges. In quantitative terms, it is remarkable to observe little if any degree of idiosyncrasy across systems as diverse as virus, bacteria and yeast. The universality of this phenomenon suggests that its emergence might be understood from general principles, giving rise to the exciting prospect that evolution might be statistically predictable at the macroscopic level. We discuss these possibilities in the light of the various theories of adaptation that have been proposed and delineate future directions of research. PMID:25815007

Influence of the particle size and intrinsic magnetic characteristics on the coercivity of sintered magnets

NASA Astrophysics Data System (ADS)

Turilli, G.; Paoluzi, A.; Lucenti, M.; Pareti, L.

1992-02-01

Using sintered specimens of Ba-hexaferrite powders as a model system, a study was made of the dependence of coercivity on the particle dimensions and on the temperature from RT up to the Curie temperature. The temperature behaviour of the coercive and anisotropy field are the same in single-domain particle specimens while they are rather different in polydomain particle specimens. However, the coercivity behaviour of both systems can be fitted well up to 350°C using a simple relation between Hc, HA, and Ms. Further contributions to the coercivity have to be taken into account at higher temperatures.

Nuclear reactor shutdown control rod assembly

DOEpatents

Bilibin, Konstantin

1988-01-01

A temperature responsive, self-actuated nuclear reactor shutdown control rod assembly 10. The upper end 18 of a lower drive line 17 fits within the lower end of an upper drive line 12. The lower end (not shown) of the lower drive line 17 is connected to a neutron absorber. During normal temperature conditions the lower drive line 17 is supported by detent means 22,26. When an overtemperature condition occurs thermal actuation means 34 urges ring 26 upwardly sufficiently to allow balls 22 to move radially outwardly thereby allowing lower drive line 17 to move downwardly toward the core of the nuclear reactor resulting in automatic reduction of the reactor powder.

Compaction dynamics of crunchy granular material

NASA Astrophysics Data System (ADS)

Guillard, François; Golshan, Pouya; Shen, Luming; Valdès, Julio R.; Einav, Itai

2017-06-01

Compaction of brittle porous material leads to a wide variety of densification patterns. Static compaction bands occurs naturally in rocks or bones, and have important consequences in industry for the manufacturing of powder tablets or metallic foams for example. Recently, oscillatory compaction bands have been observed in brittle porous media like snow or cereals. We will discuss the great variety of densification patterns arising during the compaction of puffed rice, including erratic compaction at low velocity, one or several travelling compaction bands at medium velocity and homogeneous compaction at larger velocity. The conditions of existence of each pattern are studied thanks to a numerical spring lattice model undergoing breakage and is mapped to the phase diagram of the patterns based on dimensionless characteristic quantities. This also allows to rationalise the evolution of the compaction behaviour during a single test. Finally, the localisation of compaction bands is linked to the strain rate sensitivity of the material.

Integrally cored ceramic investment casting mold fabricated by ceramic stereolithography

NASA Astrophysics Data System (ADS)

Bae, Chang-Jun

Superalloy airfoils are produced by investment casting (IC), which uses ceramic cores and wax patterns with ceramic shell molds. Hollow cored superalloy airfoils in a gas turbine engine are an example of complex IC parts. The complex internal hollow cavities of the airfoil are designed to conduct cooling air through one or more passageways. These complex internal passageways have been fabricated by a lost wax process requiring several processing steps; core preparation, injection molding for wax pattern, and dipping process for ceramic shell molds. Several steps generate problems such as high cost and decreased accuracy of the ceramic mold. For example, costly tooling and production delay are required to produce mold dies for complex cores and wax patterns used in injection molding, resulting in a big obstacle for prototypes and smaller production runs. Rather than using separate cores, patterns, and shell molds, it would be advantageous to directly produce a mold that has the casting cavity and the ceramic core by one process. Ceramic stereolithography (CerSLA) can be used to directly fabricate the integrally cored ceramic casting mold (ICCM). CerSLA builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This dissertation addresses the integrally cored casting ceramic mold (ICCM), the ceramic core with a ceramic mold shell in a single patternless construction, fabricated by ceramic stereolithography (CerSLA). CerSLA is considered as an alternative method to replace lost wax processes, for small production runs or designs too complex for conventional cores and patterns. The main topic is the development of methods to successfully fabricate an ICCM by CerSLA from refractory silica, as well as related issues. The related issues are the segregation of coarse fused silica powders in a layer, the degree of segregation parameter to prevent segregation, and sintering and cristobalite transformation in fused silica compacts.

The hitchhiker's guide to altruism: gene-culture coevolution, and the internalization of norms.

PubMed

Gintis, Herbert

2003-02-21

An internal norm is a pattern of behavior enforced in part by internal sanctions, such as shame, guilt and loss of self-esteem, as opposed to purely external sanctions, such as material rewards and punishment. The ability to internalize norms is widespread among humans, although in some so-called "sociopaths", this capacity is diminished or lacking. Suppose there is one genetic locus that controls the capacity to internalize norms. This model shows that if an internal norm is fitness enhancing, then for plausible patterns of socialization, the allele for internalization of norms is evolutionarily stable. This framework can be used to model Herbert Simon's (1990) explanation of altruism, showing that altruistic norms can "hitchhike" on the general tendency of internal norms to be personally fitness-enhancing. A multi-level selection, gene-culture coevolution argument then explains why individually fitness-reducing internal norms are likely to be prosocial as opposed to socially harmful.

The manifestation of depression in the context of urban poverty: a factor analysis of the Children's Depression Inventory in low-income urban youth.

PubMed

Taylor, Jeremy J; Grant, Kathryn E; Amrhein, Kelly; Carter, Jocelyn Smith; Farahmand, Farahnaz; Harrison, Aubrey; Thomas, Kina J; Carleton, Russell A; Lugo-Hernandez, Eduardo; Katz, Brian N

2014-12-01

The current study used confirmatory factor analysis (CFA) to compare the fit of 2 factor structures for the Children's Depression Inventory (CDI) in an urban community sample of low-income youth. Results suggest that the 6-factor model developed by Craighead and colleagues (1998) was a strong fit to the pattern of symptoms reported by low-income urban youth and was a superior fit with these data than the original 5-factor model of the CDI (Kovacs, 1992). Additionally, results indicated that all 6 factors from the Craighead model contributed to the measurement of depression, including School Problems and Externalizing Problems especially for older adolescents. This pattern of findings may reflect distinct contextual influences of urban poverty on the manifestation and measurement of depression in youth. (c) 2014 APA, all rights reserved.

Characterizing differences in mortality at the low end of the fitness spectrum in individuals with cardiovascular disease.

PubMed

Mandic, Sandra; Myers, Jonathan; Oliveira, Ricardo B; Abella, Joshua; Froelicher, Victor F

2010-06-01

A graded but nonlinear relationship exists between fitness and mortality, with the greatest mortality differences occurring between the least-fit (first, Q1) and the next-least-fit (second, Q2) quintiles of fitness. The purpose of this study was to compare clinical characteristics, exercise test responses, and physical activity (PA) patterns in Q1 versus Q2 in patients with cardiovascular disease (CVD). Observational retrospective study. A total of 5101 patients with a history of CVD underwent clinical treadmill testing and were followed up for 9.1+/-5.5 years. Patients were classified into quintiles of exercise capacity measured in metabolic equivalents. Clinical characteristics, treadmill test results, and recreational PA patterns were compared between Q1 (n = 923) and Q2 (n = 929). Q1 had a nearly two-fold increase in age-adjusted relative risk of cardiovascular mortality compared with Q2 (hazard ratio: 3.79 vs. 2.04, P<0.05; reference: fittest quintile). Q1 patients were older, had more extensive use of medications, and were more likely to have a history of typical angina (35 vs. 28%), myocardial infarction (30 vs. 24%), chronic heart failure (25 vs. 14%), claudication (15 vs. 9%) and stroke (9 vs. 6%) compared with Q2 (all comparisons: P<0.05). Recent and lifetime recreational PA was not different between the two groups. Greater severity of disease in the least-fit versus the next-least-fit quintile likely contributes to but cannot fully explain marked differences in mortality rates in CVD patients. To achieve potential survival benefits, our results suggest that unfit CVD patients should engage in exercise programs of sufficient volume and intensity to improve fitness.

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.

Additive Manufacturing of Shape Memory Alloys

NASA Astrophysics Data System (ADS)

Van Humbeeck, Jan

2018-04-01

Selective Laser Melting (SLM) is an additive manufacturing production process, also called 3D printing, in which functional, complex parts are produced by selectively melting patterns in consecutive layers of powder with a laser beam. The pattern the laser beam is following is controlled by software that calculates the pattern by slicing a 3D CAD model of the part to be constructed. Apart from SLM, also other additive manufacturing techniques such as EBM (Electron Beam Melting), FDM (Fused Deposition Modelling), WAAM (Wire Arc Additive Manufacturing), LENS (Laser Engineered Net Shaping such as Laser Cladding) and binder jetting allow to construct complete parts layer upon layer. But since more experience of AM of shape memory alloys is collected by SLM, this paper will overview the potentials, limits and problems of producing NiTi parts by SLM.

Non-noble metal based metallization systems

NASA Technical Reports Server (NTRS)

Garcia, A., III

1983-01-01

The results of efforts to produce a nonsilver metallization system for silicon photovoltaic cells are given. The system uses a metallization system based on molybdenum, tin, and titanium hydride. The initial work in this system was done using the MIDFILM process. The MIDFILM process attains a line resolution comparable to photoresist methods with a process related to screen printing. The surface to be processed is first coated with a thin layer of photopolymer material. Upon exposure to ultraviolet light through a suitable mask, the polymer in the non-pattern area crosslinks and becomes hard. The unexposed pattern areas remain tacky. The conductor material is then applied in the form of a dry mixture of metal which adheres to the tacky pattern area. The assemblage is then fired to ash the photopolymer and sinter the conductor powder.

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.

Variations in motor unit recruitment patterns occur within and between muscles in the running rat (Rattus norvegicus).

PubMed

Hodson-Tole, E F; Wakeling, J M

2007-07-01

Motor units are generally considered to follow a set, orderly pattern of recruitment within each muscle with activation occurring in the slowest through to the fastest units. A growing body of evidence, however, suggests that recruitment patterns may not always follow such an orderly sequence. Here we investigate whether motor unit recruitment patterns vary within and between the ankle extensor muscles of the rat running at 40 cm s(-1) on a level treadmill. In the past it has been difficult to quantify motor unit recruitment patterns during locomotion; however, recent application of wavelet analysis techniques has made such detailed analysis of motor unit recruitment possible. Here we present methods for quantifying the interplay of fast and slow motor unit recruitment based on their myoelectric signals. Myoelectric data were collected from soleus, plantaris and medial gastrocnemius muscles representing populations of slow, mixed and fast fibres, respectively, and providing a good opportunity to relate myoelectric frequency content to motor unit recruitment patterns. Following wavelet transformation, principal component analysis quantified signal intensity and relative frequency content. Significant differences in signal frequency content occurred between different time points within a stride (P<0.001). We optimised high- and low-frequency wavelets to the major signals from the fast and slow motor units. The goodness-of-fit of the optimised wavelets to the signal intensity was high for all three muscles (r2>0.98). The low-frequency band had a significantly better fit to signals from the soleus muscle (P<0.001), while the high-frequency band had a significantly better fit to the medial gastrocnemius (P<0.001).

The distribution of the indicator height for age of Mexican children and adolescents with Down syndrome according to different reference standards.

PubMed

Peña Rivera, Adriana Graciela; Vásquez Garibay, Edgar Manuel; Troyo Sanromán, Rogelio; Romero Velarde, Enrique; Caro Sabido, Erika; Ramírez Díaz, Joanie

2015-06-01

To compare the indicator height for age in Mexican children with Down Syndrome (DS) with two different reference patterns of growth (American and Spanish) that might be suitable for the Mexican population. A cross-sectional study was performed including 235 Mexican children and adolescents of both sexes with DS aged 45 days to 16 years enrolled in two specialized schools in the metropolitan area of Guadalajara. The dependent variables were weight/age; height/age; weight/ height and BMI. The data expressed was percentiles and the chi-square test was used to compare the distribution of the height/age index with American and Spanish reference patterns. In addition, a chi-square test was performed for the goodness of fit of the height/age index, with breakpoints lower and greater than the 50th percentile. The percentage of participants who were below the 50th percentile in the height/age index was significantly higher with the Spanish vs. the American reference pattern. The chi-square test for goodness of fit showed that the frequency of cases located below the 50th percentile in the height/age index was significantly higher with the American pattern in the age groups of 0 to 36 months (p = 0.022) and 37 to 72 months (p <0.001), but it was not significant (p = 0.225) in the older than 72 months age group. The American reference pattern is a better fit for the growth of Mexican children with DS compared with the Spanish reference pattern, and the distribution profile obtained with the standard growth and WHO reference was not suitable for the assessment of children with Down syndrome. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Fitness in animals correlates with proximity to discontinuities in body mass distributions.

USGS Publications Warehouse

Angeler, David G.; Allen, Craig R.; Vila-Gispert, Anna; Almeida, David

2014-01-01

Discontinuous structure in landscapes may cause discontinuous, aggregated species body-mass patterns, reflecting the scales of structure available to animal communities within a landscape. Empirical analyses have shown that the location of species within body mass aggregations, which reflect this scale-specific organization, is non-random with regard to several ecological phenomena, including species extinctions. The propensity of declining species to have body masses proximate to discontinuities suggests that transition zones between scaling regimes ultimately decreases the ecological fitness for some species. We test this proposition using vulnerable and unthreatened fish species in Mediterranean streams with differing levels of human impact. We show that the proximity to discontinuities in body mass aggregations (“distance-to-edge”) of more vs. less fit individuals within vulnerable and unthreatened populations differs. Specifically, regression analysis between the scaled mass index, a proxy of animal fitness, and distance-to-edge reveals negative and positive relationships for vulnerable and unthreatened species, respectively. That is, fitness is higher close to discontinuities in vulnerable populations and toward the center of body mass aggregation groups in unthreatened populations. Our results demonstrate the suitability of the discontinuity framework for scrutinizing non-random patterns of environmental impact in populations. Further exploration of the usefulness of this method across other ecosystems and organism groups is warranted.

Genome-wide heterogeneity of nucleotide substitution model fit.

PubMed

Arbiza, Leonardo; Patricio, Mateus; Dopazo, Hernán; Posada, David

2011-01-01

At a genomic scale, the patterns that have shaped molecular evolution are believed to be largely heterogeneous. Consequently, comparative analyses should use appropriate probabilistic substitution models that capture the main features under which different genomic regions have evolved. While efforts have concentrated in the development and understanding of model selection techniques, no descriptions of overall relative substitution model fit at the genome level have been reported. Here, we provide a characterization of best-fit substitution models across three genomic data sets including coding regions from mammals, vertebrates, and Drosophila (24,000 alignments). According to the Akaike Information Criterion (AIC), 82 of 88 models considered were selected as best-fit models at least in one occasion, although with very different frequencies. Most parameter estimates also varied broadly among genes. Patterns found for vertebrates and Drosophila were quite similar and often more complex than those found in mammals. Phylogenetic trees derived from models in the 95% confidence interval set showed much less variance and were significantly closer to the tree estimated under the best-fit model than trees derived from models outside this interval. Although alternative criteria selected simpler models than the AIC, they suggested similar patterns. All together our results show that at a genomic scale, different gene alignments for the same set of taxa are best explained by a large variety of different substitution models and that model choice has implications on different parameter estimates including the inferred phylogenetic trees. After taking into account the differences related to sample size, our results suggest a noticeable diversity in the underlying evolutionary process. All together, we conclude that the use of model selection techniques is important to obtain consistent phylogenetic estimates from real data at a genomic scale.

Injury Rate and Patterns Among CrossFit Athletes.

PubMed

Weisenthal, Benjamin M; Beck, Christopher A; Maloney, Michael D; DeHaven, Kenneth E; Giordano, Brian D

2014-04-01

CrossFit is a type of competitive exercise program that has gained widespread recognition. To date, there have been no studies that have formally examined injury rates among CrossFit participants or factors that may contribute to injury rates. To establish an injury rate among CrossFit participants and to identify trends and associations between injury rates and demographic categories, gym characteristics, and athletic abilities among CrossFit participants. Descriptive epidemiology study. A survey was conducted, based on validated epidemiologic injury surveillance methods, to identify patterns of injury among CrossFit participants. It was sent to CrossFit gyms in Rochester, New York; New York City, New York; and Philadelphia, Pennsylvania, and made available via a posting on the main CrossFit website. Participants were encouraged to distribute it further, and as such, there were responses from a wide geographical location. Inclusion criteria included participating in CrossFit training at a CrossFit gym in the United States. Data were collected from October 2012 to February 2013. Data analysis was performed using Fisher exact tests and chi-square tests. A total of 486 CrossFit participants completed the survey, and 386 met the inclusion criteria. The overall injury rate was determined to be 19.4% (75/386). Males (53/231) were injured more frequently than females (21/150; P = .03). Across all exercises, injury rates were significantly different (P < .001), with shoulder (21/84), low back (12/84), and knee (11/84) being the most commonly injured overall. The shoulder was most commonly injured in gymnastic movements, and the low back was most commonly injured in power lifting movements. Most participants did not report prior injury (72/89; P < .001) or discomfort in the area (58/88; P < .001). Last, the injury rate was significantly decreased with trainer involvement (P = .028). The injury rate in CrossFit was approximately 20%. Males were more likely to sustain an injury than females. The involvement of trainers in coaching participants on their form and guiding them through the workout correlates with a decreased injury rate. The shoulder and lower back were the most commonly injured in gymnastic and power lifting movements, respectively. Participants reported primarily acute and fairly mild injuries.

Assessment of potential effects of water produced from coalbed natural gas development on macroinvertebrate and algal communities in the Powder River and Tongue River, Wyoming and Montana, 2010

USGS Publications Warehouse

Peterson, David A.; Hargett, Eric G.; Feldman, David L.

2011-01-01

Ongoing development of coalbed natural gas in the Powder River structural basin in Wyoming and Montana led to formation of an interagency aquatic task group to address concerns about the effects of the resulting production water on biological communities in streams of the area. Ecological assessments, made from 2005–08 under the direction of the task group, indicated biological condition of the macroinvertebrate and algal communities in the middle reaches of the Powder was lower than in the upper or lower reaches. On the basis of the 2005–08 results, sampling of the macroinvertebrate and algae communities was conducted at 18 sites on the mainstem Powder River and 6 sites on the mainstem Tongue River in 2010. Sampling-site locations were selected on a paired approach, with sites located upstream and downstream of discharge points and tributaries associated with coalbed natural gas development. Differences in biological condition among site pairs were evaluated graphically and statistically using multiple lines of evidence that included macroinvertebrate and algal community metrics (such as taxa richness, relative abundance, functional feeding groups, and tolerance) and output from observed/expected (O/E) macroinvertebrate models from Wyoming and Montana. Multiple lines of evidence indicated a decline in biological condition in the middle reaches of the Powder River, potentially indicating cumulative effects from coalbed natural gas discharges within one or more reaches between Flying E Creek and Wild Horse Creek in Wyoming. The maximum concentrations of alkalinity in the Powder River also occurred in the middle reaches. Biological condition in the upper and lower reaches of the Powder River was variable, with declines between some site pairs, such as upstream and downstream of Dry Fork and Willow Creek, and increases at others, such as upstream and downstream of Beaver Creek. Biological condition at site pairs on the Tongue River showed an increase in one case, near the Wyoming-Montana border, and a decrease in another case, upstream of Tongue River Reservoir. Few significant differences were noted from upstream to downstream of Prairie Dog Creek, a major tributary to the Tongue River. Further study would be needed to confirm the observed patterns and choose areas to examine in greater detail.

Patterns in Calabi-Yau Distributions

NASA Astrophysics Data System (ADS)

He, Yang-Hui; Jejjala, Vishnu; Pontiggia, Luca

2017-09-01

We explore the distribution of topological numbers in Calabi-Yau manifolds, using the Kreuzer-Skarke dataset of hypersurfaces in toric varieties as a testing ground. While the Hodge numbers are well-known to exhibit mirror symmetry, patterns in frequencies of combination thereof exhibit striking new patterns. We find pseudo-Voigt and Planckian distributions with high confidence and exact fit for many substructures. The patterns indicate typicality within the landscape of Calabi-Yau manifolds of various dimension.

General method of pattern classification using the two-domain theory

NASA Technical Reports Server (NTRS)

Rorvig, Mark E. (Inventor)

1993-01-01

Human beings judge patterns (such as images) by complex mental processes, some of which may not be known, while computing machines extract features. By representing the human judgements with simple measurements and reducing them and the machine extracted features to a common metric space and fitting them by regression, the judgements of human experts rendered on a sample of patterns may be imposed on a pattern population to provide automatic classification.

General method of pattern classification using the two-domain theory

NASA Technical Reports Server (NTRS)

Rorvig, Mark E. (Inventor)

1990-01-01

Human beings judge patterns (such as images) by complex mental processes, some of which may not be known, while computing machines extract features. By representing the human judgements with simple measurements and reducing them and the machine extracted features to a common metric space and fitting them by regression, the judgements of human experts rendered on a sample of patterns may be imposed on a pattern population to provide automatic classification.

Social structure and intracohort variation in physical fitness among elderly males in a traditional Third World society.

PubMed

Beall, C M; Goldstein, M C; Feldman, E S

1985-06-01

This paper examines the relationship between physical fitness and activity among elderly males in the traditional rural community of Chetbesi, Nepal. It takes advantage of the unique character of the Hindu caste system to implement a quasiexperimental research design that approximates random assignment to high and low activity levels. The members of the Sarki caste have lower heart rates and systolic blood pressure, relative to other castes, at each of three submaximal workloads and during recovery from bicycle ergometer exercise. Direct observation and physiologic monitoring show that the Sarkis engage in more frequent and extended periods of heavy labor. Thus intracohort variation in physical fitness and activity patterns among the Chetbesi elderly is a function of birth into a socially defined group rather than of self-selection. This pattern of differential fitness may typify the process of aging in many stratified traditional and modernizing societies where socially delimited segments of the population perform the bulk of the hard work. Intrapopulation differences aside, comparison of Sarkis and non-Sarkis with other samples reveals that both lie within the reported range of variation. The rural, unmechanized, agricultural lifestyle and mountain environment of Chetbesi do not result in exceptional fitness for residents. The Chetbesi data suggest that the popular notion that aging is less debilitating in traditional agrarian societies located in rugged mountain terrains may be a myth. The demonstration of the influence of social forces on physical fitness suggests that future research might concentrate profitably on identifying social structures that produce high levels of physical fitness.

Rare earth patterns in shergottite phosphates and residues

NASA Technical Reports Server (NTRS)

Laul, J. C.

1987-01-01

Leaching experiments with 1M HCl on ALHA 77005 powder show that rare earth elements (REE) are concentrated in accessory phosphate phases (whitlockite, apatite) that govern the REE patterns of bulk shergottites. The REE patterns of whitlockite are typically light REE-depleted with a negative Eu anomaly and show a hump at the heavy REE side, while the REE pattern of apatite (in Shergotty) is light REE-enriched. Parent magmas are calculated from the modal compositions of residues of ALHA 77005, Shergotty, and EETA 79001. The parent magmas lack a Eu anomaly, indicating that plagioclase was a late-stage crystallizing phase and that it probably crystallized before the phosphates. The parent magmas of ALHA 77005 and Shergotty have similar REE patterns, with a subchondritic Nd/Sm ratio. However, the Sm/Nd isotopoics require a light REE-depleted source for ALHA 77005 (if the crystallization age is less than 600 Myr) and a light REE-enriched source for Shergotty. Distant Nd and Sr isotopic signatures may suggest different source regions for shergottites.

Minimally invasive percutaneous nephrolithotomy in preschool age children with kidney calculi (including stones induced by melamine-contaminated milk powder).

PubMed

Yan, Xiang; Al-Hayek, Samih; Gan, Weidong; Zhu, Wei; Li, Xiaogong; Guo, Hongqian

2012-10-01

This study was undertaken to assess the safety and efficacy of minimally invasive percutaneous nephrolithotomy (mini-PCNL) using ureteroscope and pneumatic intracorporeal lithotripsy in preschool age children with kidney calculi. We studied 27 renal units in 20 patients of preschool age (≤ 6 years) who underwent mini-PCNL at our institute. The mean age was 42.6 months (range 14-68 months). The average stone burden was 1.85 cm (range 0.9-2.8 cm). Eight patients aged 14 to 58 months had been exposed to melamine-tainted powdered formula. The mini-PCNL was performed with an X-ray-guided peripheral puncture. Minimal tract dilatation was undertaken to fit a 14-16 Fr peel-away sheath. Ureteroscope and pneumatic intracorporeal lithotripsy were used to fragment the stones. Complete clearance was achieved in 23 renal units (85.2 %) with mini-PCNL monotherapy. This has increased to 92.6 % after adjunctive ESWL. The average fall in hemoglobin was 1.28 g/dL. None of the patients required blood transfusion. The median length of hospital stay was 8.2 days. Patients were followed up every 6 months for 2 years. There has been only one recurrence of stone and no long-term complications. Mini-PCNL is a effective treatment for pediatric kidney stones refractory to extracorporeal shock wave lithotripsy, including stones induced by melamine-contaminated milk powder. The "mini-PCNL" technique, which uses ureteroscope and pneumatic intracorporeal lithotripsy, is a safe and feasible modality for treating renal calculi in preschool age children.

Adsorptive removal of microcystin-LR from surface and wastewater using tyre-based powdered activated carbon: Kinetics and isotherms.

PubMed

Mashile, Phodiso P; Mpupa, Anele; Nomngongo, Philiswa N

2018-04-01

Microcystin LR (MC-LR) is a highly toxic compound and it is known for its adverse health effect on both humans and animals. Due to the ineffectiveness of conventional water treatments methods, for the past decades, researchers have been developing cost-effective ways of removing MC-LR from water bodies. This study reports the application of powdered activated carbon (PAC) obtained from the waste tyre for the removal of MC-LR. The choice of the adsorbent was chosen due to its attractive properties. The prepared tyre-based PAC was found to have the large surface area (1111 m 2  g -1 ). The detection of MC-LR was achieved using high performance liquid chromatography (HPLC) coupled with a PDA detector. The experimental parameters (such as optimum pH, dosage and contact time) affecting the removal of MC-LR using tyre based-powdered activated carbon were optimized using response surface methodology (RSM). Maximum removal of MC-LR was achieved under the following optimum conditions; sample pH 4, carbon dosage concentration 10,000 mg L -1 and contact time of 34 min. Under optimum conditions, kinetic studies and adsorption isotherms reflected better fit for pseudo-second-order rate and Langmuir isotherm model, respectively. The optimized method was applied for the removal of MC-LR in wastewater sample. The effluent and influent sample contained initial concentrations ranging from 0.52 to 8.54 μg L -1 and the removal efficiency was 100%. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biosorption of Basic Green 4 from aqueous solution by Ananas comosus (pineapple) leaf powder.

PubMed

Chowdhury, Shamik; Chakraborty, Sagnik; Saha, Papita

2011-06-01

Biosorption characteristics of Ananas comosus (pineapple) leaf powder was investigated for decolorization of Basic Green 4 (BG 4), a cationic dye from its aqueous solutions employing a batch experimental set-up. Parameters that influence the sorption process such as pH, biosorbent dosage, contact time, initial dye concentration and temperature were systematically studied. The optimum conditions for removal of BG 4 were found to be pH 9.0, contact time=150 min, biosorbent dosage=5.0 g L(-1), initial dye concentration=50 mg L(-1). The temperature had a strong influence on the biosorption process. Further, the biosorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Brunauer, Emmett, Teller (BET) surface area and pore size analysis. Experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The biosorption process followed the Langmuir isotherm model with high coefficients of correlation (R(2)>0.99) at different temperatures. The pseudo second order kinetic model fitted well in correlation to the experimental results. Activation energy of the biosorption process (E(a)) was found to be 45.79 kJ mol(-1) by using the Arrhenius equation, indicating chemisorption nature of BG 4 sorption onto pineapple leaf powder. Thermodynamic parameters suggest that the biosorption process is spontaneous and exothermic in nature. Overall, the present findings suggest that this environmentally friendly, efficient and low-cost biosorbent may be useful for the removal of BG 4 from aqueous media. Copyright © 2011 Elsevier B.V. All rights reserved.

Emergent neutrality drives phytoplankton species coexistence

PubMed Central

Segura, Angel M.; Calliari, Danilo; Kruk, Carla; Conde, Daniel; Bonilla, Sylvia; Fort, Hugo

2011-01-01

The mechanisms that drive species coexistence and community dynamics have long puzzled ecologists. Here, we explain species coexistence, size structure and diversity patterns in a phytoplankton community using a combination of four fundamental factors: organism traits, size-based constraints, hydrology and species competition. Using a ‘microscopic’ Lotka–Volterra competition (MLVC) model (i.e. with explicit recipes to compute its parameters), we provide a mechanistic explanation of species coexistence along a niche axis (i.e. organismic volume). We based our model on empirically measured quantities, minimal ecological assumptions and stochastic processes. In nature, we found aggregated patterns of species biovolume (i.e. clumps) along the volume axis and a peak in species richness. Both patterns were reproduced by the MLVC model. Observed clumps corresponded to niche zones (volumes) where species fitness was highest, or where fitness was equal among competing species. The latter implies the action of equalizing processes, which would suggest emergent neutrality as a plausible mechanism to explain community patterns. PMID:21177680

Method for immobilizing particulate materials in a packed bed

DOEpatents

Even, W.R. Jr.; Guthrie, S.E.; Raber, T.N.; Wally, K.; Whinnery, L.L.; Zifer, T.

1999-02-02

The present invention pertains generally to immobilizing particulate matter contained in a packed bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that (a) the particulate retains its essential chemical nature, (b) the local movement of the particulate particles is not unduly restricted, (c) bulk powder migration and is prevented, (d) physical and chemical access to the particulate is unchanged over time, and (e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of an individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport. 4 figs.

The effect of growth temperature on the irreversibility line of MPMG YBCO bulk with Y2O3 layer

NASA Astrophysics Data System (ADS)

Kurnaz, Sedat; Çakır, Bakiye; Aydıner, Alev

2017-07-01

In this study, three kinds of YBCO samples which are named Y1040, Y1050 and Y1060 were fabricated by Melt-Powder-Melt-Growth (MPMG) method without a seed crystal. Samples seem to be single crystal. The compacted powders were located on a crucible with a buffer layer of Y2O3 to avoid liquid to spread on the furnace plate and also to support crystal growth. YBCO samples were investigated by magnetoresistivity (ρ-T) and magnetization (M-T) measurements in dc magnetic fields (parallel to c-axis) up to 5 T. Irreversibility fields (Hirr) and upper critical fields (Hc2) were obtained using 10% and 90% criteria of the normal state resistivity value from ρ-T curves. M-T measurements were carried out using the zero field cooling (ZFC) and field cooling (FC) processes to get irreversible temperature (Tirr). Fitting of the irreversibility line results to giant flux creep and vortex glass models were discussed. The results were found to be consistent with the results of the samples fabricated using a seed crystal. At the fabrication of MPMG YBCO, optimized temperature for crystal growth was determined to be around 1050-1060 °C.

Method for immobilizing particulate materials in a packed bed

DOEpatents

Even, Jr., William R.; Guthrie, Stephen E.; Raber, Thomas N.; Wally, Karl; Whinnery, LeRoy L.; Zifer, Thomas

1999-01-01

The present invention pertains generally to immobilizing particulate matter contained in a "packed" bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that a) the particulate retains its essential chemical nature, b) the local movement of the particulate particles is not unduly restricted, c) bulk powder migration and is prevented, d) physical and chemical access to the particulate is unchanged over time, and e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport.

Black bean coats: New source of anthocyanins stabilized by β-cyclodextrin copigmentation in a sport beverage.

PubMed

Aguilera, Yolanda; Mojica, Luis; Rebollo-Hernanz, Miguel; Berhow, Mark; de Mejía, Elvira González; Martín-Cabrejas, María A

2016-12-01

Anthocyanin-rich powders and aqueous extracts, with high antioxidant activities, were obtained from black bean seed coats and applied to colour a sport beverage. Idaho and Otomi bean coats were extracted in water-citric acid 2% (1/50, w/v), stirring for 4h at 40°C. Anthocyanins from Idaho and Otomi extracts (1.83mg and 1.02mg C3G/g, respectively) were applied to a commercially available sport beverage, with and without 2% β-cyclodextrin (βCD) under light and darkness conditions for 10days, and stored at 4°C and 25°C for 6weeks. At different light and storage conditions, anthocyanin degradation fitted a first-order reaction model. All bean coat anthocyanins combined with βCD showed extended half-life (up to 13months), higher D-values (up to 43months) and fewer differences in colourimetric properties (lightness, chroma and hue angle) under darkness and 4°C conditions. These black bean coat aqueous extracts and powders might represent natural alternatives to synthetic colorants, ecologically extracted, and with a high antioxidant potential. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of marginal and internal adaptation of copings fabricated from three different fabrication techniques: An in vitro study.

PubMed

Arora, Aman; Yadav, Avneet; Upadhyaya, Viram; Jain, Prachi; Verma, Mrinalini

2018-01-01

The purpose of this study was to compare the marginal and internal adaptation of cobalt-chromium (Co-Cr) copings fabricated from conventional wax pattern, three-dimensional (3D)-printed resin pattern, and laser sintering technique. A total of thirty copings were made, out of which ten copings were made from 3D-printed resin pattern (Group A), ten from inlay wax pattern (Group B), and ten copings were obtained from direct metal laser sintering (DMLS) technique (Group C). All the thirty samples were seated on their respective dies and sectioned carefully using a laser jet cutter and were evaluated for marginal and internal gaps at the predetermined areas using a stereomicroscope. The values were then analyzed using one-way ANOVA test and post hoc Bonferroni test. One-way ANOVA showed lowest mean marginal discrepancy for DMLS and highest value for copings fabricated from inlay wax. The values for internal discrepancy were highest for DMLS (169.38) and lowest for 3D-printed resin pattern fabricated copings (133.87). Post hoc Bonferroni test for both marginal and internal discrepancies showed nonsignificant difference when Group A was compared to Group B ( P > 0.05) and significant when Group A was compared with Group C ( P < 0.05). Group B showed significant difference ( P < 0.05) when compared with Group C. Marginal and internal discrepancies of all the three casting techniques were within clinically acceptable values. Marginal fit of DMLS was superior as compared to other two techniques, whereas when internal fit was evaluated, conventional technique showed the best internal fit.

Switching-angle sample spinning NMR probe with a commercially available 20 kHz spinning system

NASA Astrophysics Data System (ADS)

Mizuno, Takashi; Takegoshi, K.; Terao, Takehiko

2004-11-01

A switching-angle sample spinning (SASS) probe workable at high spinning speeds was developed using a commercially available rotor/housing system. Details of the construction are described. As application examples of the SASS probe, we report experiments of powder pattern separation at the spinning speed of 20 kHz and broadband 13C- 13C polarization transfer at 16 kHz.

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.

Detection of {sup 14}N and {sup 35}Cl in cocaine base and hydrochloride using NQR, NMR, and SQUID techniques

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

Yesinowski, J.P.; Buess, M.L.; Garroway, A.N.

1995-07-01

Results from {sup 14}N pure NQR of cocaine in the free base form (cocaine base) yield a nuclear quadrupole coupling constant (NQCC) e{sup 2}Qq/h of 5.0229 ({+-}0.0001) MHz and an asymmetry parameter {eta} of 0.0395 ({+-}0.0001) at 295 K, with corresponding values of 5.0460 ({+-}0.0013) MHz and 0.0353 ({+-}0.0008) at 77 K. Both pure NQR (at 295-77 K) and a superconducting quantum interference device (SQUID) detector (at 4.2 K) were used to measure the very low (<1 MHz) {sup 14}N transition frequencies in cocaine hydrochloride; at 295 K the NQCC is 1.1780 ({+-}0.0014) MHz and the asymmetry parameter is 0.2632more » ({+-}0.0034). Stepping the carrier frequency enables one to obtain a powder pattern without the severe intensity distortions that otherwise arise from finite pulse power. A powder pattern simulation using an NQCC value of 5.027 MHz and an asymmetry parameter {eta} of 0.2 agrees reasonably well with the experimental stepped-frequency spectrum. The use of pure NQR for providing nondestructive, quantitative, and highly specific detection of crystalline compounds is discussed, as are experimental strategies. 31 refs., 8 figs., 1 tab.« less

Biosorption of Cd+2 by green plant biomass, Araucaria heterophylla: characterization, kinetic, isotherm and thermodynamic studies

NASA Astrophysics Data System (ADS)

Sarada, B.; Krishna Prasad, M.; Kishore Kumar, K.; Murthy, Ch V. R.

2017-11-01

The present study attempted to analyze the biosorption behavior of novel biosorbent, Araucaria heterophylla (green plant) biomass, to remove Cd+2 from solutions against various parameters, i.e., initial metal ion concentration, pH, temperature, sorbent dosage and biomass particle size. The maximum biosorption was found to be 90.02% at pH 5.5 and biosorption capacity ( q e) of Cd+2 is 9.2506 mg g-1. The Langmuir and Freundlich equilibrium adsorption isotherms were studied and it was observed that Freundlich model is the best fit than the Langmuir model with correlation co-efficient of 0.999. Kinetic studies indicated that the biosorption process of Cd+2 well followed the pseudo-second-order model with R 2 0.999. Thermodynamic studies observed that the process is exothermic (Δ H ° negative). Free energy change (Δ G °) with negative sign reflected the feasibility and spontaneous nature of the process. The chemical functional -OH groups, CH2 stretching vibrations, C=O carbonyl group of alcohol, C=O carbonyl group of amide, P=O stretching vibrations and -CH groups were involved in the biosorption process. The XRD pattern of the A. heterophylla was found to be mostly amorphous in nature. The SEM studies showed Cd+2 biosorption on selective grains of the biosorbent. It was concluded that A. heterophylla leaf powder can be used as an effective, low-cost, and environmentally friendly biosorbent for the removal of Cd+2 from aqueous solution.

Polymorphic Transformation of Indomethacin during Hot Melt Extrusion Granulation: Process and Dissolution Control.

PubMed

Xu, Ting; Nahar, Kajalajit; Dave, Rutesh; Bates, Simon; Morris, Kenneth

2018-05-10

To study and elucidate the effect of the intensity and duration of processing stresses on the possible solid-state changes during a hot melt extrusion granulation process. Blends of α-indomethacin and PEG 3350 (w/w 4:1) were granulated using various screw sizes/designs on the melt extruder under different temperature regimes. Differential Scanning Calorimetry and X-ray Powder Diffraction were employed for characterization. The dissolution behavior of the pure polymorphs and the resulting granules was determined using in-situ fiber optic UV testing system. An XRPD quantitation method using Excel full pattern fitting was developed to determine the concentration of each constituent (amorphous, α and γ indomethacin and PEG) in samples collected from each functioning zone and in granules. Analysis of in-process samples and granules revealed that higher temperature (≥130°C) and shear stress accelerated the process induced phase transitions from amorphous and/or the α form to γ indomethacin during heating stage. However, rapid cooling resulted in an increased percentage of the α form allowing isolation of the meta-stable form. By determining the conditions that either prevent or facilitate process induced transformations of IMC polymorphs during melt granulation, a design space was developed to control the polymorph present in the resulting granules. This represents the conditions necessary to balance the thermodynamic relationships between the polymorphs of the IMC system and the kinetics of the possible transformations as a function of the processing stresses.

Effect of Cu2+ substitution on the structural, optical and magnetic behaviour ofchemically derived manganese ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Vasuki, G.; Balu, T.

2018-06-01

Mixed spinel copper manganese ferrite (CuXMn1‑XFe2O4, X = 0, 0.25, 0.5, 0.75, 1) nanoparticles were synthesized by chemical co-precipitation technique. From the powder x-ray diffraction analysis the lattice constant, volume of unit cell, x-ray density, hopping lengths, crystallite size, surface area, dislocation density and microstrain were calculated. The substitution of Cu2+ ions shows a considerable reduction in the crystallite size of manganese ferrite from 34 nm to 22 nm. Further a linear fit of Williamson-Hall plot has been drawn to determine the microstrain and crystallite size. The crystallite size and morphology were further observed through high resolution transmission electron microscope and scanning electron microscope. The diffraction rings observed from selected area electron diffraction pattern exhibits the crystalline nature of all the samples. The energy dispersive x-ray analysis shows the composition of all the elements incorporated in the synthesized nanomaterials. FTIR studies reveal the absorption peaks that correspond to the metal-oxygen vibrations in the tetrahedral and octahedral sites. From the UV–vis absorption spectra the band gap energy, refractive index and optical dielectric constant were determined. Magnetic studies carried out using vibrating sample magnetometer shows interesting behaviour in the variation of magnetisation and coercivity. Peculiar magnetic behaviour is observed when Cu2+ ions are substituted in manganese ferrites. All the synthesized materials have very low value of squareness ratio which attributes to the superparamagnetic behaviour.

Structural and electrical properties of (La,Nd){sub 2}(Cu,Ni)O{sub 4+{delta}}

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

Suck, S.I.; Park, D.S.; Park, S.J.

The temperature dependence of electrical properties for K{sub 2}NiF{sub 4} type oxide, La{sub 2}Cu{sub 1{minus}{ital x}}Ni{sub {ital x}}O{sub 4+{delta}} and La{sub 1.8}Nd{sub 0.2}Cu{sub 1{minus}{ital x}}Ni{sub {ital x}}O{sub 4+{delta}} ({ital x}=0.0, 0.025, 0.05, 0.10, and 0.20), were investigated between R.T and 1173 K in view of potential thermoelectric material. Structural studies were made using a Rietveld pattern fitting refinement with X-ray powder diffraction data. Lattice parameter in {ital c} axis decreases with Ni content, while {ital a} increases and {ital b} is almost invariant. The electrical conductivity increases with a substitution of Ni ion in Cu sites, showing the transition betweenmore » quasi-metallic and semiconducting. However, the absolute value of 5 and 10 mol % Ni-doped composition are lower than that of un-doped La{sub 2}CuO{sub 4+{delta}}. The thermoelectric power decreases continuously with Ni content. These behaviors were considered to an ability of Ni ion for incorporating an excess oxygen owing to the easier accessibility of Ni{sup 3+} and deleting of the local Cu 3d band by 3d{sup 8} configuration of Ni{sup 2+}. Power factors with doping of Ni are not enhanced. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.« less

Structural, mechanical and vibrational study of uranyl silicate mineral soddyite by DFT calculations

NASA Astrophysics Data System (ADS)

Colmenero, Francisco; Bonales, Laura J.; Cobos, Joaquín; Timón, Vicente

2017-09-01

Uranyl silicate mineral soddyite, (UO2)2(SiO4)·2(H2O), is a fundamental component of the paragenetic sequence of secondary phases that arises from the weathering of uraninite ore deposits and corrosion of spent nuclear fuel. In this work, soddyite was studied by first principle calculations based on the density functional theory. As far as we know, this is the first time that soddyite structure is determined theoretically. The computed structure of soddyite reproduces the one determined experimentally by X-Ray diffraction (orthorhombic symmetry, spatial group Fddd O2; lattice parameters a = 8.334 Å, b = 11.212 Å; c = 18.668 Å). Lattice parameters, bond lengths, bond angles and X-Ray powder pattern were found to be in very good agreement with their experimental counterparts. Furthermore, the mechanical properties were obtained and the satisfaction of the Born conditions for mechanical stability of the structure was demonstrated by means of calculations of the elasticity tensor. The equation of state of soddyite was obtained by fitting lattice volumes and pressures to a fourth order Birch-Murnahan equation of state. The Raman spectrum was also computed by means of density functional perturbation theory and compared with the experimental spectrum obtained from a natural soddyite sample. The results were also found in agreement with the experimental data. A normal mode analysis of the theoretical spectra was carried out and used in order to assign the main bands of the Raman spectrum.

B11 NMR in the layered diborides OsB2 and RuB2

NASA Astrophysics Data System (ADS)

Suh, B. J.; Zong, X.; Singh, Y.; Niazi, A.; Johnston, D. C.

2007-10-01

B11 nuclear magnetic resonance (NMR) measurements have been performed on B11 enriched OsB2 and RuB2 polycrystalline powder samples in an external field of 4.7T and in the temperature range, 4.2K

Effect of processing on fracture toughness of silicon carbide as determined by Vickers indentations

NASA Technical Reports Server (NTRS)

Dannels, Christine M.; Dutta, Sunil

1989-01-01

Several alpha-SiC materials were processed by hot isostatic pressing (HIPing) and by sintering an alpha-SiC powder containing boron and carbon. Several beta-SiC materials were processed by HIPing a beta-SiC powder with boron and carbon additions. The fracture toughnesses K(sub 1c) of these beta- and alpha-SiC materials were estimated from measurements of Vickers indentations. The three formulas used to estimate K(sub 1c) from the indentation fracture patterns resulted in three ranges of K(sub 1c) estimates. Furthermore, each formula measured the effects of processing differently. All three estimates indicated that fine-grained HIPed alpha-SiC has a higher K(sub 1c) than coarsed-grained sintered alpha-SiC. Hot isostatically pressed beta-SiC, which had an ultrafine grain structure, exhibited a K(sub 1c) comparable to that of HIPed alpha-SiC.

High-Pressure Polymorph of NaBiO3.

PubMed

Naa, Octavianti; Kumada, Nobuhiro; Miura, Akira; Takei, Takahiro; Azuma, Masaki; Kusano, Yoshihiro; Oka, Kengo

2016-06-20

A new high-pressure polymorph of NaBiO3 (hereafter β-NaBiO3) was synthesized under the conditions of 6 GPa and 600 °C. The powder X-ray diffraction pattern of this new phase was indexed with a hexagonal cell of a = 9.968(1) Å and c = 3.2933(4) Å. Crystal structure refinement using synchrotron powder X-ray diffraction data led to RWP = 8.53% and RP = 5.55%, and the crystal structure was closely related with that of Ba2SrY6O12. No photocatalytic activity for phenol decomposition was observed under visible-light irradiation in spite of a good performance for its mother compound, NaBiO3. The optical band-gap energy of β-NaBiO3 was narrower than that of NaBiO3, which was confirmed with density of states curves simulated by first-principles density functional theory calculation.

Fabrication of robust tooling for mass production of polymeric microfluidic devices

NASA Astrophysics Data System (ADS)

Fu, G.; Tor, S. B.; Loh, N. H.; Hardt, D. E.

2010-08-01

Polymer microfluidic devices are gaining popularity for bio-applications. In both commonly used methods for the fabrication of polymer microfluidic devices, i.e. injection molding and hot-embossing, the quality of a mold insert is of high importance. Micro powder injection molding (μPIM) provides a suitable option for metal mold insert fabrication. In this paper, two mold inserts with micro-features of different patterns and sizes were produced using 316L stainless steel powder and an in-house binder system. The mold inserts were successfully used to produce cyclic olefin copolymer (COC, trade name TOPAS) micromixer plates with micro-channels of widths 100 µm and 50 µm. Compared with CNC-machined hot work steel mold inserts, the quality of the micro-channels is better as far as geometrical quality and dimensional tolerance are concerned. However, surface finish and flatness of the μPIM mold inserts are inferior to those of CNC-machined mold inserts.

Valence fluctuating compound α-YbAlB4 studied by 174Yb Mössbauer spectroscopy and X-ray diffraction using synchrotron radiation

NASA Astrophysics Data System (ADS)

Oura, Momoko; Ikeda, Shugo; Masuda, Ryo; Kobayashi, Yasuhiro; Seto, Makoto; Yoda, Yoshitaka; Hirao, Naohisa; Kawaguchi, Saori I.; Ohishi, Yasuo; Suzuki, Shintaro; Kuga, Kentaro; Nakatsuji, Satoru; Kobayashi, Hisao

2018-05-01

The structural properties and the Yb 4 f electronic state of the valence fluctuating α-YbAlB4 have been investigated by powder X-ray diffraction under pressure and 174Yb Mössbauer spectroscopy with magnetic fields at low temperature, respectively, using synchrotron radiation. Powder X-ray diffraction patterns showed that the crystal structure does not change up to p ∼ 18 GPa at 8 K and the volume decreases smoothly. However, the pressure dependence of the difference in the structure factor between the (060) and (061) diffraction lines changes at ∼ 3.4 GPa, indicating the change of atomic coordination parameters. The 174Yb Mössbauer spectroscopy measurements at 2 K with 10 and 50 kOe suggest that the electrical quadrupole interaction changes by applied magnetic fields.

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.

28. Photocopy of 1921 architectural drawing titled: BUILDING 59, PATTERN ...

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

28. Photocopy of 1921 architectural drawing titled: BUILDING 59, PATTERN SHOP, PROPOSED EXTENSION SHOWING floor plans for the first and second floors, elevation detail of how the north extension would fit the existing building, and a plan view of site with adjacent buildings. Drawing No. 6167, File No. 651-23. - Puget Sound Naval Shipyard, Pattern Shop, Farragut Avenue, Bremerton, Kitsap County, WA

Biaxially textured articles formed by powder metallurgy

DOEpatents

Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

2003-08-05

A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of ternary mixtures consisting of: Ni powder, Cu powder, and Al powder, Ni powder, Cr powder, and Al powder; Ni powder, W powder and Al powder; Ni powder, V powder, and Al powder; Ni powder, Mo powder, and Al powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}<100> orientation texture; and further having a Curie temperature less than that of pure Ni.

Normative functional fitness standards and trends of Portuguese older adults: cross-cultural comparisons.

PubMed

Marques, Elisa A; Baptista, Fátima; Santos, Rute; Vale, Susana; Santos, Diana A; Silva, Analiza M; Mota, Jorge; Sardinha, Luís B

2014-01-01

This cross-sectional study was designed to develop normative functional fitness standards for the Portuguese older adults, to analyze age and gender patterns of decline, to compare the fitness level of Portuguese older adults with that of older adults in other countries, and to evaluate the fitness level of Portuguese older adults relative to recently published criterion fitness standards associated with maintaining physical independence. A sample of 4,712 independent-living older adults, age 65-103 yr, was evaluated using the Senior Fitness Test battery. Age-group normative fitness scores are reported for the 10th, 25th, 50th, 75th, and 90th percentiles. Results indicate that both women and men experience age-related losses in all components of functional fitness, with their rate of decline being greater than that observed in other populations, a trend which may cause Portuguese older adults to be at greater risk for loss of independence in later years. These newly established normative standards make it possible to assess individual fitness level and provide a basis for implementing population-wide health strategies to counteract early loss of independence.

Patterns and Predictors of Language and Literacy Abilities 4-10 Years in the Longitudinal Study of Australian Children

PubMed Central

Zubrick, Stephen R.; Taylor, Catherine L.; Christensen, Daniel

2015-01-01

Aims Oral language is the foundation of literacy. Naturally, policies and practices to promote children’s literacy begin in early childhood and have a strong focus on developing children’s oral language, especially for children with known risk factors for low language ability. The underlying assumption is that children’s progress along the oral to literate continuum is stable and predictable, such that low language ability foretells low literacy ability. This study investigated patterns and predictors of children’s oral language and literacy abilities at 4, 6, 8 and 10 years. The study sample comprised 2,316 to 2,792 children from the first nationally representative Longitudinal Study of Australian Children (LSAC). Six developmental patterns were observed, a stable middle-high pattern, a stable low pattern, an improving pattern, a declining pattern, a fluctuating low pattern, and a fluctuating middle-high pattern. Most children (69%) fit a stable middle-high pattern. By contrast, less than 1% of children fit a stable low pattern. These results challenged the view that children’s progress along the oral to literate continuum is stable and predictable. Findings Multivariate logistic regression was used to investigate risks for low literacy ability at 10 years and sensitivity-specificity analysis was used to examine the predictive utility of the multivariate model. Predictors were modelled as risk variables with the lowest level of risk as the reference category. In the multivariate model, substantial risks for low literacy ability at 10 years, in order of descending magnitude, were: low school readiness, Aboriginal and/or Torres Strait Islander status and low language ability at 8 years. Moderate risks were high temperamental reactivity, low language ability at 4 years, and low language ability at 6 years. The following risk factors were not statistically significant in the multivariate model: Low maternal consistency, low family income, health care card, child not read to at home, maternal smoking, maternal education, family structure, temperamental persistence, and socio-economic area disadvantage. The results of the sensitivity-specificity analysis showed that a well-fitted multivariate model featuring risks of substantive magnitude did not do particularly well in predicting low literacy ability at 10 years. PMID:26352436

A Fundamental Relationship Between Genotype Frequencies and Fitnesses

PubMed Central

Lachance, Joseph

2008-01-01

The set of possible postselection genotype frequencies in an infinite, randomly mating population is found. Geometric mean heterozygote frequency divided by geometric mean homozygote frequency equals two times the geometric mean heterozygote fitness divided by geometric mean homozygote fitness. The ratio of genotype frequencies provides a measure of genetic variation that is independent of allele frequencies. When this ratio does not equal two, either selection or population structure is present. Within-population HapMap data show population-specific patterns, while pooled data show an excess of homozygotes. PMID:18780726

Aromaticity Parameters in Asphalt Binders Calculated From Profile Fitting X-ray Line Spectra Using Pearson VII and Pseudo-Voigt Functions

NASA Astrophysics Data System (ADS)

Shirokoff, J.; Lewis, J. Courtenay

2010-10-01

The aromaticity and crystallite parameters in asphalt binders are calculated from data obtained after profile fitting x-ray line spectra using Pearson VII and pseudo-Voigt functions. The results are presented and discussed in terms of the peak profile fit parameters used, peak deconvolution procedure, and differences in calculated values that can arise owing to peak shape and additional peaks present in the pattern. These results have implications concerning the evaluation and performance of asphalt binders used in highways and road applications.

Typing DNA profiles from previously enhanced fingerprints using direct PCR.

PubMed

Templeton, Jennifer E L; Taylor, Duncan; Handt, Oliva; Linacre, Adrian

2017-07-01

Fingermarks are a source of human identification both through the ridge patterns and DNA profiling. Typing nuclear STR DNA markers from previously enhanced fingermarks provides an alternative method of utilising the limited fingermark deposit that can be left behind during a criminal act. Dusting with fingerprint powders is a standard method used in classical fingermark enhancement and can affect DNA data. The ability to generate informative DNA profiles from powdered fingerprints using direct PCR swabs was investigated. Direct PCR was used as the opportunity to generate usable DNA profiles after performing any of the standard DNA extraction processes is minimal. Omitting the extraction step will, for many samples, be the key to success if there is limited sample DNA. DNA profiles were generated by direct PCR from 160 fingermarks after treatment with one of the following dactyloscopic fingerprint powders: white hadonite; silver aluminium; HiFi Volcano silk black; or black magnetic fingerprint powder. This was achieved by a combination of an optimised double-swabbing technique and swab media, omission of the extraction step to minimise loss of critical low-template DNA, and additional AmpliTaq Gold ® DNA polymerase to boost the PCR. Ninety eight out of 160 samples (61%) were considered 'up-loadable' to the Australian National Criminal Investigation DNA Database (NCIDD). The method described required a minimum of working steps, equipment and reagents, and was completed within 4h. Direct PCR allows the generation of DNA profiles from enhanced prints without the need to increase PCR cycle numbers beyond manufacturer's recommendations. Particular emphasis was placed on preventing contamination by applying strict protocols and avoiding the use of previously used fingerprint brushes. Based on this extensive survey, the data provided indicate minimal effects of any of these four powders on the chance of obtaining DNA profiles from enhanced fingermarks. Copyright © 2017 Elsevier B.V. All rights reserved.

Daily Physical Activity and Physical Fitness in 11-to 15-year-old Trained and Untrained Turkish Boys

PubMed Central

Güvenç, Alpay; Açikada, Caner; Aslan, Alper; Özer, Kamil

2011-01-01

The aims of this study were to assess levels and patterns of physical activity (PA) in relation to age and regular sport activity, and to examine its relationship to physical fitness in trained and untrained boys. One hundred forty-seven 11-to 15- year-old boys (73 trained and 74 untrained) participated in this study. Trained boys, comprised of 26 soccer, 25 handball and 22 volleyball players, had been training regularly for at least one year. The intensity, duration and frequency of PA were assessed from four complete days of heart rate monitoring with 15-seconds sampling intervals. Aerobic fitness was assessed by determining peakVO2 with a portable breath-by-breath gas analyzer (Cosmed K4b2) and the running speeds at fixed lactate concentrations during an incremental running test. Anaerobic fitness was evalu-ated with the Wingate Anaerobic Test. Skinfold thicknesses from eight sites and Tanner stages of pubic hair were also obtained. Based on 15-s heart rate data, instead of continuous activity, multiple short bouts of moderate and vigorous PA, lasting up to one minute, were characteristic of daily PA patterns of both trained and untrained boys. PA levels of trained boys were higher than untrained boys (p < 0.01) and the levels of PA decreased with age and maturation in both groups (p < 0.05). Daily PA variables were related to body fatness in both groups (p < 0.05), but the relationships were not consistent in the trained group. Daily PA variables were also related to aerobic fitness in the untrained group (p < 0.05) and these relationships were somewhat better with vigorous PA, whereas in the trained group, none of the PA variables were related to any of the aerobic fitness indices (p > 0.05). No relationship was observed between PA variables and anaerobic fitness in either group (p> 0.05). It seems that such relationships may somewhat depend on the fitness level of the subjects. Key points PA levels of trained boys were higher than untrained boys and the levels of PA decreased with age and maturation in both groups. Based on the 15-s HR data, instead of continuous activity, multiple short bouts of moderate and vigorous PA, lasting up to one minute, were characteristic of daily PA patterns of both trained and untrained boys. Daily PA variables were related to aerobic fitness in the untrained group and these relationships were somewhat better with vigorous PA (>70% HRR), whereas in the trained group, none of the PA variables were related to any of the aerobic fitness indices. Neither peak nor mean power values were related to any of the daily PA variables in both trained and untrained groups. PMID:24150625

Accuracy of Person-Fit Statistics: A Monte Carlo Study of the Influence of Aberrance Rates

ERIC Educational Resources Information Center

St-Onge, Christina; Valois, Pierre; Abdous, Belkacem; Germain, Stephane

2011-01-01

Using a Monte Carlo experimental design, this research examined the relationship between answer patterns' aberrance rates and person-fit statistics (PFS) accuracy. It was observed that as the aberrance rate increased, the detection rates of PFS also increased until, in some situations, a peak was reached and then the detection rates of PFS…

Set of Measures for Physical Fitness Measures Development. Report No. 11.

ERIC Educational Resources Information Center

Ostrove, Nancy; And Others

A report is given of the development of sets of measures with which to determine the physical fitness status and activity patterns of 10- to 17-year-old school children and youths. Three groups of physical education experts worked on the task of identifying and agreeing upon appropriate measures. The first panel determined that the most valid…

Goodness of Fit of Skills Assessment Approaches: Insights from Patterns of Real vs. Synthetic Data Sets

ERIC Educational Resources Information Center

Beheshti, Behzad; Desmarais, Michel C.

2015-01-01

This study investigates the issue of the goodness of fit of different skills assessment models using both synthetic and real data. Synthetic data is generated from the different skills assessment models. The results show wide differences of performances between the skills assessment models over synthetic data sets. The set of relative performances…

The Sexual Dimorphic Association of Cardiorespiratory Fitness to Working Memory in Children

ERIC Educational Resources Information Center

Drollette, Eric S.; Scudder, Mark R.; Raine, Lauren B.; Davis Moore, R.; Pontifex, Matthew B.; Erickson, Kirk I.; Hillman, Charles H.

2016-01-01

The present investigation examined the sexual dimorphic patterns of cardiorespiratory fitness to working memory in preadolescent children (age range: 7.7-10.9). Data were collected in three separate studies (Study 1: n = 97, 42 females; Study 2: n = 95, 45 females; Study 3: n = 84, 37 females). All participants completed a cardiorespiratory…

Type A and B behavior patterns and self-reported health symptoms and stress: examining individual and organizational fit.

PubMed

Matteson, M T; Ivancevich, J M

1982-08-01

This article describes a preliminary investigation of the proposition that organizations, as well as people, can be classified along a Type A and B behavior pattern dimension and that the resulting match or lack thereof between individual and organizational behavior patterns is related to various health indices. A sample of 315 medical technologists were classified as either Type As or Bs and as working in either Type A or B environments. Results supported the hypotheses that (1) Type Bs in B organizations report the fewest negative health symptoms; (2) Type As in A organizations report the most; and (3) Type Bs in A organizations and Type As in B organizations report an intermediate level of symptoms. The results are treated within the framework of a person-environment fit model and the implications of the findings are discussed.

Decomposition Analyses Applied to a Complex Ultradian Biorhythm: The Oscillating NADH Oxidase Activity of Plasma Membranes Having a Potential Time-Keeping (Clock) Function

PubMed Central

Foster, Ken; Anwar, Nasim; Pogue, Rhea; Morré, Dorothy M.; Keenan, T. W.; Morré, D. James

2003-01-01

Seasonal decomposition analyses were applied to the statistical evaluation of an oscillating activity for a plasma membrane NADH oxidase activity with a temperature compensated period of 24 min. The decomposition fits were used to validate the cyclic oscillatory pattern. Three measured values, average percentage error (MAPE), a measure of the periodic oscillation, mean average deviation (MAD), a measure of the absolute average deviations from the fitted values, and mean standard deviation (MSD), the measure of standard deviation from the fitted values plus R-squared and the Henriksson-Merton p value were used to evaluate accuracy. Decomposition was carried out by fitting a trend line to the data, then detrending the data if necessary, by subtracting the trend component. The data, with or without detrending, were then smoothed by subtracting a centered moving average of length equal to the period length determined by Fourier analysis. Finally, the time series were decomposed into cyclic and error components. The findings not only validate the periodic nature of the major oscillations but suggest, as well, that the minor intervening fluctuations also recur within each period with a reproducible pattern of recurrence. PMID:19330112

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.

Catalyst for cracking kerosene

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

Hsie, C. H.

1985-06-04

A catalyst capable of cracking kerosene under lower pressure and temperature comprising kerosene; metal powder mixture of chromium powder, copper powder, lead powder, zinc powder, nickel powder, manganese powder in an amount of 12 to 13 parts by weight per 100 parts by weight of said kerosene; sulfuric acid in an amount of 15 to 30 parts by weight per 100 parts by weight of said kerosene; inorganic powder mixture of aluminum oxide powder, serpentine powder, alum powder, magnesium oxide powder, limestone powder, slake lime powder, silica powder, and granite powder in an amount of 150 to 170 parts bymore » weight per 100 parts by weight of said kerosene.« less

Floral signposts: testing the significance of visual ‘nectar guides’ for pollinator behaviour and plant fitness

PubMed Central

Hansen, Dennis M.; Van der Niet, Timotheüs; Johnson, Steven D.

2012-01-01

Nectar guides, contrasting patterns on flowers that supposedly direct pollinators towards a concealed nectar reward, are taxonomically widespread. However, there have been few studies of their functional significance and effects on plant fitness. Most previous studies focused on pollinator behaviour and used artificial flowers in laboratory settings. We experimentally investigated the role of putative nectar guides in a natural system: the South African iris Lapeirousia oreogena, whose flowers have a clearly visible pattern of six white arrow-markings pointing towards the narrow entrance of the long corolla tube, and its sole pollinator, a long-proboscid nemestrinid fly. We painted over none, some or all of the white arrow-markings with ink that matched the colour of the corolla background. Although arrow-marking removal had little effect on the approaches by flies to flowers from a distance, it dramatically reduced the likelihood of proboscis insertion. Export of pollen dye analogue (an estimate of male fitness) was reduced to almost zero in flowers from which all nectar guides had been removed, and fruit set (a measure of female fitness) was also significantly reduced. Our results confirm that the markings on L. oreogena flowers serve as nectar guides and suggest that they are under strong selective maintenance through both male and female fitness components in this pollination system. PMID:21795269

CrossFit athletes exhibit high symmetry of fundamental movement patterns. A cross-sectional study

PubMed Central

Tafuri, Silvio; Notarnicola, Angela; Monno, Antonello; Ferretti, Francesco; Moretti, Biagio

2016-01-01

Summary Background even if CrossFit training programs accounted actually more than 7500 gyms affiliated in the USA and more than 2000 in Europe and involved today more than 1 million of people, actually there were not several studies about the effect of the CrossFit on the health and sport performance. The aim of these research was to evaluate the performance in 7 fundamental movement patterns using a standardized methods, the Functional Movement Screen (FMS). Methods we enrolled three groups of athletes (age 17–40 years; >6 months of training programs): CrossFitters, body builders and professional weightlifters. FMS test was performed to all people enrolled. Scores of FMS test was examined comparing three groups. Results no differences in the three groups were showed in the mean score values of each test and in total score, except for shoulder mobility test (higher among CrossFitters) and trunk stability push-up test (higher among weightlifter). Agreement between the test performed on the two sides was higher in CrossFit groups for hurdle step (93.2%), in line lung (86%), rotary stability test (95.3%) and shoulder mobility (90.7%; p<0.001). Conclusions CrossFitters seem to have a high level of concordance in the scores achieved in bilateral test. CrossFit seems to produce marked symmetry in some fundamental movements compared to weightlifting and bodybuilding. PMID:27331045

CrossFit athletes exhibit high symmetry of fundamental movement patterns. A cross-sectional study.

PubMed

Tafuri, Silvio; Notarnicola, Angela; Monno, Antonello; Ferretti, Francesco; Moretti, Biagio

2016-01-01

even if CrossFit training programs accounted actually more than 7500 gyms affiliated in the USA and more than 2000 in Europe and involved today more than 1 million of people, actually there were not several studies about the effect of the CrossFit on the health and sport performance. The aim of these research was to evaluate the performance in 7 fundamental movement patterns using a standardized methods, the Functional Movement Screen (FMS). we enrolled three groups of athletes (age 17-40 years; >6 months of training programs): CrossFitters, body builders and professional weightlifters. FMS test was performed to all people enrolled. Scores of FMS test was examined comparing three groups. no differences in the three groups were showed in the mean score values of each test and in total score, except for shoulder mobility test (higher among CrossFitters) and trunk stability push-up test (higher among weightlifter). Agreement between the test performed on the two sides was higher in CrossFit groups for hurdle step (93.2%), in line lung (86%), rotary stability test (95.3%) and shoulder mobility (90.7%; p<0.001). CrossFitters seem to have a high level of concordance in the scores achieved in bilateral test. CrossFit seems to produce marked symmetry in some fundamental movements compared to weightlifting and bodybuilding.

Synthesis, characterization and photoluminescence properties of Bi³⁺ co-doped CaSiO₃:Eu³⁺ nanophosphor.

PubMed

Kumar, M Madesh; Krishna, R Hari; Nagabhushana, B M; Shivakumara, C

2015-03-15

Ceramic luminescent powders with the composition Ca(0.96-x)Eu0.04Bi(x)SiO3 (x=0.01-0.05) were prepared by solution combustion method. The nanopowders are characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and photoluminescence (PL) techniques. PXRD patterns of calcined (950°C for 3h) Ca(0.96-x)Eu0.04Bi(x)SiO3 powders exhibit monoclinic phase with mean crystallite sizes ranging from 28 to 48 nm. SEM micrographs show the products are foamy, agglomerated and fluffy in nature due to the large amount of gases liberated during combustion reaction. TEM micrograph shows the crystalline characteristics of the nanoparticles. Upon 280 nm excitation, the photoluminescence of the Ca(0.96-x)Eu0.04Bi(x)SiO3 particles show red emission at 611 nm corresponding to 5D0→7F2 transition. It is observed that PL intensity increases with Bi(3+) concentration. Our work demonstrates very interesting energy transfer from Bi(3+) to Eu(3+) in CaSiO3 host. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

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.