Effects of chemical composite, puffing temperature and intermediate moisture content on physical properties of potato and apple slices

NASA Astrophysics Data System (ADS)

Tabtaing, S.; Paengkanya, S.; Tanthong, P.

2017-09-01

Puffing technique is the process that can improve texture and volumetric of crisp fruit and vegetable. However, the effect of chemical composite in foods on puffing characteristics is still lack of study. Therefore, potato and apple slices were comparative study on their physical properties. Potato and apple were sliced into 2.5 mm thickness and 2.5 cm in diameter. Potato slices were treated by hot water for 2 min while apple slices were not treatment. After that, they were dried in 3 steps. First step, they were dried by hot air at temperature of 90°C until their moisture content reached to 30, 40, and 50 % dry basis. Then they were puffed by hot air at temperature of 130, 150, and 170°C for 2 min. Finally, they were dried again by hot air at temperature of 90°C until their final moisture content reached to 4% dry basis. The experimental results showed that chemical composite of food affected on physical properties of puffed product. Puffed potato had higher volume ratio than those puffed apple because potato slices contains starch. The higher starch content provided more hard texture of potato than those apples. Puffing temperature and moisture content strongly affected on the color, volume ratio, and textural properties of puffed potato slices. In addition, the high drying rate of puffed product observed at high puffing temperature and higher moisture content.

In vitro aging behavior of dental composites considering the influence of filler content, storage media and incubation time

PubMed Central

Maletz, Reinhard; Ottl, Peter; Warkentin, Mareike

2018-01-01

Objective Over time dental composites age due to mechanical impacts such as chewing and chemical impacts such as saliva enzymes and food ingredients. For this research, the focus was placed on chemical degradation. The objective of this study was to simulate hydrolysis by using different food simulating liquids and to assess their impact on the mechanical parameter Vickers microhardness (MHV) and the physicochemical parameter contact angle (CA). Methods Specimen of three composites (d = 6 mm, h = 2 mm; n = 435) classified with respect to their filler content (wt%), namely low-filled, medium-filled and highly-filled, were stored for 0, 14, 30, 90 and 180 days in artificial saliva (pH 7), citric acid (pH 3; pH 5), lactic acid (pH 3; pH 5) and ethanol (40%vol; 60%vol) and assessed regarding to MHV and CA. Statistics: Kruskal-Wallis test, stepwise linear regression, bivariate Spearman Rank Correlation (p < 0.05). Results While stored in artificial saliva, acid and ethanol the CA decreased especially for the low- and medium-filled composites. It was shown that rising the filler content caused less surface changes in the CA. Storage in ethanol led to a significant decrease of MHV of all composites. Regression analysis showed that the effect of in vitro aging on MHV was mainly influenced by the composite material and therefore by filler content (R2 = 0.67; p < 0.05). In contrast, the CA is more influenced by incubation time and filler content (R2 = 0.2; p < 0.05) leading to a higher risk of plaque accumulation over time. Significance: In vitro aging showed significant changes on the mechanical and physicochemical properties of dental composites which may shorten their long-term functionality. In conclusion, it can be stated, that the type of composite material, especially rising filler content seems to improve the materials’ resistance against the processes of chemical degradation. PMID:29630621

The correlationship between the metabolizable energy content, chemical composition and color score in different sources of corn DDGS.

PubMed

Jie, Yong-Z; Zhang, Jian-Y; Zhao, Li-H; Ma, Qiu-G; Ji, Cheng

2013-09-25

This study was conducted to evaluate the apparent metabolizable energy (AME) and true metabolizable energy (TME) contents in 30 sources of corn distillers dried grains with solubles (DDGS) in adult roosters, and establish the prediction equations to estimate the AME and TME value based on its chemical composition and color score. Twenty-eight sources of corn DDGS made from several processing plants in 11 provinces of China and others imported from the United States. DDGS were analyzed for their metabolizable energy (ME) contents, measured for color score and chemical composition (crude protein, crude fat, ash, neutral detergent fiber, acid detergent fiber), to predict the equation of ME in DDGS. A precision-fed rooster assay was used, each DDGS sample was tube fed (50 g) to adult roosters. The experiment was conducted as a randomized incomplete block design with 3 periods. Ninety-five adult roosters were used in each period, with 90 being fed the DDGS samples and 5 being fasted to estimate basal endogenous energy losses. Results showed that the AME ranged from 5.93 to 12.19 MJ/kg, TME ranged from 7.28 to 13.54 MJ/kg. Correlations were found between ME and ash content (-0.64, P < 0.01) and between ME and yellowness score (0.39, P < 0.05) of the DDGS samples. Furthermore, the best-fit regression equation for AME content of DDGS based on chemical composition and color score was AME = 6.57111 + 0.51475 GE - 0.10003 NDF + 0.13380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R2 = 0.70). The best-fit regression equation for TME content of DDGS was TME = 7.92283 + 0.51475 GE - 0.10003 NDF + 0.13380 ADF + 0.07057 fat - 0.57029 ash - 0.02437 L (R2 = 0.70). This experiment suggested that measuring the chemical composition and color score of a corn DDGS sample may provide a quality parameter for identifying corn DDGS sources energy digestibility and metabolizable energy content.

Fabrication of Lightweight Radiation Shielding Composite Materials by Field Assisted Sintering Technique (FAST)

NASA Technical Reports Server (NTRS)

Prasad, Narasimha; Trivedi, Sudhir; Chen, Henry; Kutcher, Susan; Zhang, Dajie; Singh, Jogender

2017-01-01

Advances in radiation shielding technologies are needed to protect humans and electronic components from all threats of space radiation over long durations. In this paper, we report on the use of the innovative and novel fabrication technology known as Field Assisted Sintering Technology (FAST) to fabricate lightweight material with enhanced radiation shielding strength to safeguard humans and electronics suitable for next generation space exploration missions. The base materials we investigated were aluminum (Al), the current standard material for space hardware, and Ultra-High Molecular Weight Polyethylene (UHMWPE), which has high hydrogen content and resistance to nuclear reaction from neutrons, making it a good shielding material for both gamma radiation and particles. UHMWPE also has high resistance to corrosive chemicals, extremely low moisture sensitivity, very low coefficient of friction, and high resistance to abrasion. We reinforced the base materials by adding high density (ie, high atomic weight) metallic material into the composite. These filler materials included: boron carbide (B4C), tungsten (W), tungsten carbide (WC) and gadolinium (Gd).

Chemical recycling of scrap composites

NASA Technical Reports Server (NTRS)

Allred, Ronald E.; Salas, Richard M.

1994-01-01

There are no well-developed technologies for recycling composite materials other than grinding to produce fillers. New approaches are needed to reclaim these valuable resources. Chemical or tertiary recycling, conversion of polymers into low molecular weight hydrocarbons for reuse as chemicals or fuels, is emerging as the most practical means for obtaining value from waste plastics and composites. Adherent Technologies is exploring a low-temperature catalytic process for recycling plastics and composites. Laboratory results show that all types of plastics, thermosets as well as thermoplastics, can be converted in high yields to valuable hydrocarbon products. This novel catalytic process runs at 200 C, conversion times are rapid, the process is closed and, thus, nonpolluting, and no highly toxic gas or liquid products have been observed so no negative environmental impact will result from its implementation. Tests on reclamation of composite materials show that epoxy, imide, and engineering thermoplastic matrices can be converted to low molecular weight hydrocarbons leaving behind the reinforcing fibers for reuse as composite reinforcements in secondary, lower-performance applications. Chemical recycling is also a means to dispose of sensitive or classified organic materials without incineration and provides a means to eliminate or reduce mixed hazardous wastes containing organic materials.

Chemical compositions, free amino acid contents and antioxidant activities of Hanwoo (Bos taurus coreanae) beef by cut.

PubMed

Oh, Mirae; Kim, Eun-Kyung; Jeon, Byong-Tae; Tang, Yujiao; Kim, Moon S; Seong, Hye-Jin; Moon, Sang-Ho

2016-09-01

The objective of this study was to evaluate chemical compositions, free amino acid contents, and antioxidant activities of different cuts of Hanwoo (Bos taurus coreanae) beef. Beef preferences and prices in the Korean market depend on cut. Therefore, comparisons were made between high-preference cuts (group 1 [G1], including loin, tenderloin, and rib) and low-preference cuts (group 2 [G2], including brisket, topside, and shank). Meat samples were collected from 10 fattened cows. Crude fat content was significantly higher in G1 than in G2 (p<0.05). The amounts of crude protein and total free amino acid were negatively correlated with crude fat content (p<0.05). Overall G2 contained higher levels of free amino acids with antioxidant activity than G1. Antioxidant activities were also significantly higher in G2 compared with G1 (p<0.05). In conclusion, providing consumers with positive information about G2 as found in this study could help health-conscious consumers choosing among beef products and further promote increased consumption of low-preference beef cuts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-functional composite materials for catalysis and chemical mechanical planarization

NASA Astrophysics Data System (ADS)

Coutinho, Cecil A.

2009-12-01

Composite materials formed from two or more functionally different materials offer a versatile avenue to create a tailored material with well defined traits. Within this dissertation research, multi-functional composites were synthesized based on organic and inorganic materials. The functionally of these composites was experimentally tested and a semi-empirical model describing the sedimentation behavior of these particles was developed. This first objective involved the fabrication of microcomposites consisting of titanium dioxide (TiO2) nanoparticles confined within porous, microgels of a thermo-responsive polymer for use in the photocatalytic treatment of wastewater. TiO2 has been shown to be an excellent photocatalyst with potential applications in advanced oxidative processes such as wastewater remediation. Upon UV irradiation, short-lived electron-hole pairs are generated, which produce oxidative species that degrade simple organic contaminants. The rapid sedimentation of these microcomposites provided an easy gravimetric separation after remediation. Methyl orange was used as a model organic contaminant to investigate the kinetics of photodegradation under a range of concentrations and pH conditions. Although after prolonged periods of UV irradiation (˜8-13 hrs), the titania-microgels also degrade, regeneration of the microcomposites was straightforward via the addition of polymer microgels with no loss in photocatalytic activity of the reformed microcomposites. The second objective within this dissertation involved the systematic development of abrasive microcomposite particles containing well dispersed nanoparticles of ceria in an organic/inorganic hybrid polymeric particle for use in chemical mechanical polishing/planarization (CMP). A challenge in IC fabrication involves the defect-free planarization of silicon oxide films for successful multi-layer deposition. Planarization studies conducted with the microcomposites prepared in this research, yield

Vibration Damping Response of Composite Materials

DTIC Science & Technology

1991-04-01

using a diamond-impregnated cutoff wheel mounted on a milling machine . This procedure was followed to minimize damage to the composite specimens prior to...Development Report Vibration Damping Response of Composite Materials by Roger M. Crane 0E DTIC0 • ELECTE 16 - MAY 28 19914S8 0 E 5; 91--00524 Approved for...Damping Response of Composite Materials by Roger M. Crane TABLE OF CONTENTS Page LIST OF TABLES

Chemical and Phase Composition of Powders Obtained by Electroerosion Dispersion from WC - Co Alloys

NASA Astrophysics Data System (ADS)

Putintseva, M. N.

2004-03-01

The dependence of the chemical and phase composition of dispersed powders on the mode and medium of electroerosion dispersion and the content of cobalt in the initial alloy is considered. It is shown that the dissociation of carbon from tungsten carbide occurs even in dispersion in liquid hydrocarbon-bearing media (kerosene and industrial oils). The phase composition is primarily determined by the dispersion medium and the content of cobalt in the initial alloy. Compound tungsten-cobalt carbides and even a Co7W6 intermetallic are determined in all the powders.

Effect of the chemical composition and the structural and phases states of materials on hydrogen retention

NASA Astrophysics Data System (ADS)

Chernov, I. I.; Stal'tsov, M. S.; Kalin, B. A.; Bogachev, I. A.; Guseva, L. Yu.; Korshunov, S. N.

2017-07-01

The results of investigation of the effect of chemical composition and structural and phase states of reactor steels and vanadium alloys on their capture and retention of hydrogen introduced into the materials in various ways are presented. It is shown that, in the case of identical conditions of hydrogen introduction, the amount of hydrogen captured by austenitic steels is substantially higher than that captured by ferritic/ martensitic steels. At the same time, the EP450 ODS ferritic/martensitic steel dispersion-strengthened with nanosized yttrium oxide particles retains a substantially higher amount of hydrogen as compared to that retained in the EP450 matrix steel. The alloying of vanadium with tungsten, zirconium, and titanium leads to an increase in the amount of retained hydrogen. The effect of titanium content on hydrogen retention is found to be nonmonotonic; the phenomenon is explained from a physical view point.

Chemical composition of scales generated from oil industry and correlation to radionuclide contents and gamma-ray measurements of (210)Pb.

PubMed

Al Attar, Lina; Safia, Bassam; Abdul Ghani, Basem

2016-03-01

Scale generated from the maintenance of equipment contaminated by naturally occurring radioactive materials may contain also chemical components that cause hazardous pollution to human health and the environment. This study spotlights the characterisation of chemical pollutants in scales in relation to home-made comparison samples as no reference material for such waste exists. Analysis by energy dispersive x-ray fluorescence, with accuracy and precision better than 90%, revealed that barium was the most abundant element in scale samples, ranging from 1.4 to 38.2%. The concentrations of the toxic elements such as lead and chromium were as high as 2.5 and 1.2% respectively. Statistically, high correlation was observed between the concentration of Ba and Sr, sample density, radionuclide contents ((210)Pb and (226)Ra) and self-attenuation factor used for the radio-measurements. However, iron showed a reverse correlation. Interpretation of data with regards to the mineralogical components indicated that (226)Ra and (210)Pb co-precipitated with the insoluble salt Ba0.75Sr0.25SO4. Since both Ba and Sr have high Z, samples of high density (ρ) were accompanied with high values of self-attenuation correction factors (Cf) for the emitted radiation; correlation matrix of Pearson reached 0.935 between ρ and Cf. An attempt to eliminate the effect of the elemental composition and improve gamma measurements of (210)Pb activity concentration in scale samples was made, which showed no correction for self-attenuation was needed when sample densities were in the range 1.0-1.4 g cm(-3). For denser samples, a mathematical model was developed. Accurate determinations of radionuclide and chemical contents of scale would facilitate future Environmental Impact Assessment for the petroleum industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Metal Matrix Composite Material by Direct Metal Deposition

NASA Astrophysics Data System (ADS)

Novichenko, D.; Marants, A.; Thivillon, L.; Bertrand, P. H.; Smurov, I.

Direct Metal Deposition (DMD) is a laser cladding process for producing a protective coating on the surface of a metallic part or manufacturing layer-by-layer parts in a single-step process. The objective of this work is to demonstrate the possibility to create carbide-reinforced metal matrix composite objects. Powders of steel 16NCD13 with different volume contents of titanium carbide are tested. On the base of statistical analysis, a laser cladding processing map is constructed. Relationships between the different content of titanium carbide in a powder mixture and the material microstructure are found. Mechanism of formation of various precipitated titanium carbides is investigated.

Fabrication and thermal properties of tetradecanol/graphene aerogel form-stable composite phase change materials.

PubMed

Mu, Boyuan; Li, Min

2018-06-11

In this study, tetradecanol/graphene aerogel form-stable composite phase change materials were prepared by physical absorption. Two kinds of graphene aerogels were prepared using vitamin C and ethylenediamine to enhance the thermal conductivity of tetradecanol and prevent its leakage during phase transition. The form-stable composite phase change material exhibited excellent thermal energy storage capacity. The latent heat of the tetradecanol/graphene aerogel composite phase change materials with 5 wt.% graphene aerogel was similar to the theoretical latent heat of pure tetradecanol. The thermal conductivity of the tetradecanol/graphene aerogel composite phase change material improved gradually as the graphene aerogel content increased. The prepared tetradecanol/graphene aerogel composite phase change materials exhibited good thermal reliability and thermal stability, and no chemical reaction occurred between tetradecanol and the graphene aerogel. In addition, the latent heat and thermal conductivity of the tetradecanol/ethylenediamine-graphene aerogel composites were higher than those of tetradecanol/vitamin C-graphene aerogel composites, and the flexible shape of the ethylenediamine-graphene aerogel is suitable for application of the tetradecanol/ethylenediamine-graphene aerogel composite.

Silicate-catalyzed chemical grouting compositions

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

Not Available

1972-09-28

Chemical grouting compositions for stabilizing earth, sand, and other porous particulate formations or agglomerates of solids are described. The composition for producing a chemically grouting structure consists of an aqueous base solution of: (1) vegetative polyphenolic material consisting of condensed type tannins, and an aqueous catalyst solution of (2) a water-soluble alkali metal silicate. The polyphenolic material is present in an amount from 5% to 40% based on the weight of the base solution, and the water- soluble alkali metal silicate is present in an amount to provide from 1% to 15% SiOD2U in the silicate compound based on themore » weight of the polyphenolic material. These grouting compositions are completely safe to operating personnel and to surrounding environment, since the potassium or sodium silicate catalysts are nontoxic. (15 claims)« less

Multifunctional materials and composites

DOEpatents

Seo, Dong-Kyun; Jeon, Ki-Wan

2017-08-22

Forming multifunctional materials and composites thereof includes contacting a first material having a plurality of oxygen-containing functional groups with a chalcogenide compound, and initiating a chemical reaction between the first material and the chalcogenide compound, thereby replacing oxygen in some of the oxygen-containing functional groups with chalcogen from the chalcogen-containing compound to yield a second material having chalcogen-containing functional groups and oxygen-containing functional groups. The first material is a carbonaceous material or a macromolecular material. A product including the second material is collected and may be processed further to yield a modified product or a composite.

Chemical composition, mineral content and amino acid and lipid profiles in bones from various fish species.

PubMed

Toppe, Jogeir; Albrektsen, Sissel; Hope, Britt; Aksnes, Anders

2007-03-01

The chemical composition, content of minerals and the profiles of amino acids and fatty acids were analyzed in fish bones from eight different species of fish. Fish bones varied significantly in chemical composition. The main difference was lipid content ranging from 23 g/kg in cod (Gadus morhua) to 509 g/kg in mackerel (Scomber scombrus). In general fatty fish species showed higher lipid levels in the bones compared to lean fish species. Similarly, lower levels of protein and ash were observed in bones from fatty fish species. Protein levels differed from 363 g/kg lipid free dry matter (dm) to 568 g/kg lipid free dm with a concomitant inverse difference in ash content. Ash to protein ratio differed from 0.78 to 1.71 with the lowest level in fish that naturally have highest swimming and physical activity. Saithe (Pollachius virens) and salmon (Salmo salar) were found to be significantly different in the levels of lipid, protein and ash, and ash/protein ratio in the bones. Only small differences were observed in the level of amino acids although species specific differences were observed. The levels of Ca and P in lipid free fish bones were about the same in all species analyzed. Fatty acid profile differed in relation to total lipid levels in the fish bones, but some minor differences between fish species were observed.

Autonomic composite hydrogels by reactive printing: materials and oscillatory response.

PubMed

Kramb, R C; Buskohl, P R; Slone, C; Smith, M L; Vaia, R A

2014-03-07

Autonomic materials are those that automatically respond to a change in environmental conditions, such as temperature or chemical composition. While such materials hold incredible potential for a wide range of uses, their implementation is limited by the small number of fully-developed material systems. To broaden the number of available systems, we have developed a post-functionalization technique where a reactive Ru catalyst ink is printed onto a non-responsive polymer substrate. Using a succinimide-amine coupling reaction, patterns are printed onto co-polymer or biomacromolecular films containing primary amine functionality, such as polyacrylamide (PAAm) or poly-N-isopropyl acrylamide (PNIPAAm) copolymerized with poly-N-(3-Aminopropyl)methacrylamide (PAPMAAm). When the films are placed in the Belousov-Zhabotinsky (BZ) solution medium, the reaction takes place only inside the printed nodes. In comparison to alternative BZ systems, where Ru-containing monomers are copolymerized with base monomers, reactive printing provides facile tuning of a range of hydrogel compositions, as well as enabling the formation of mechanically robust composite monoliths. The autonomic response of the printed nodes is similar for all matrices in the BZ solution concentrations examined, where the period of oscillation decreases in response to increasing sodium bromate or nitric acid concentration. A temperature increase reduces the period of oscillations and temperature gradients are shown to function as pace-makers, dictating the direction of the autonomic response (chemical waves).

Erosion-resistant composite material

DOEpatents

Finch, C.B.; Tennery, V.J.; Curlee, R.M.

A highly erosion-resistant composite material is formed of chemical vapor-deposited titanium diboride on a sintered titanium diboride-nickel substrate. This material may be suitable for use in cutting tools, coal liquefaction systems, etc.

Wood plastic composites from agro-waste materials: Analysis of mechanical properties.

PubMed

Nourbakhsh, Amir; Ashori, Alireza

2010-04-01

This article presents the application of agro-waste materials (i.e., corn stalk, reed stalk, and oilseed stalk) in order to evaluate and compare their suitability as reinforcement for thermoplastics as an alternative to wood fibers. The effects of fiber loading and CaCO(3) content on the mechanical properties were also studied. Overall trend shows that with addition of agro-waste materials, tensile and flexural properties of the composites are significantly enhanced. Oilseed fibers showed superior mechanical properties due to their high aspect ratio and chemical characteristics. The order of increment in the mechanical properties of the composites is oilseed stalk >corn stalk>reed stalk at all fiber loadings. The tensile and flexural properties of the composite significantly decreased with increasing CaCO(3) content, due to the reduction of interface bond between the fiber and matrix. It can be concluded from this study that the used agro-waste materials are attractive reinforcements from the standpoint of their mechanical properties. Copyright 2009 Elsevier Ltd. All rights reserved.

Fabrication and evaluation of low fiber content alumina fiber/aluminum composites

NASA Technical Reports Server (NTRS)

Hack, J. E.; Strempek, G. C.

1980-01-01

The mechanical fabrication of low volume percent fiber, polycrystalline alumina fiber reinforced aluminum composites was accomplished. Wire preform material was prepared by liquid-metal infiltration of alumina fiber bundles. The wires were subsequently encapsulated with aluminum foil and fabricated into bulk composite material by hot-drawing. Extensive mechanical, thermal and chemical testing was conducted on preform and bulk material to develop a process and material data base. In addition, a preliminary investigation of mechanical forming of bulk alumina fiber reinforced aluminum composite material was conducted.

Composite Materials for Thermal Energy Storage: Enhancing Performance through Microstructures

PubMed Central

Ge, Zhiwei; Ye, Feng; Ding, Yulong

2014-01-01

Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. PMID:24591286

Enhancement of Thermoelectric Properties of PEDOT:PSS and Tellurium-PEDOT:PSS Hybrid Composites by Simple Chemical Treatment.

PubMed

Bae, Eun Jin; Kang, Young Hun; Jang, Kwang-Suk; Cho, Song Yun

2016-01-05

The thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) and tellurium- PSS (Te- PSS) hybrid composites were enhanced via simple chemical treatment. The performance of thermoelectric materials is determined by their electrical conductivity, thermal conductivity, and Seebeck coefficient. Significant enhancement of the electrical conductivity of PSS and Te- PSS hybrid composites from 787.99 and 11.01 to 4839.92 and 334.68 S cm(-1), respectively was achieved by simple chemical treatment with H2SO4. The power factor of the developed materials could be effectively tuned over a very wide range depending on the concentration of the H2SO4 solution used in the chemical treatment. The power factors of the developed thermoelectric materials were optimized to 51.85 and 284 μW m(-1) K(-2), respectively, which represent an increase of four orders of magnitude relative to the corresponding parameters of the untreated thermoelectric materials. Using the Te- PSS hybrid composites, a flexible thermoelectric generator that could be embedded in textiles was fabricated by a printing process. This thermoelectric array generates a thermoelectric voltage of 2 mV using human body heat.

Bioactive carbon-PEEK composites prepared by chemical surface treatment.

PubMed

Miyazaki, Toshiki; Matsunami, Chisato; Shirosaki, Yuki

2017-01-01

Polyetheretherketone (PEEK) has attracted much attention as an artificial intervertebral spacer for spinal reconstruction. Furthermore, PEEK plastic reinforced with carbon fiber has twice the bending strength of pure PEEK. However, the PEEK-based materials do not show ability for direct bone bonding, i.e., bioactivity. Although several trials have been conducted for enabling PEEK with bioactivity, few studies have reported on bioactive surface modification of carbon-PEEK composites. In the present study, we attempted the preparation of bioactive carbon-PEEK composites by chemical treatments with H 2 SO 4 and CaCl 2 . Bioactivity was evaluated by in vitro apatite formation in simulated body fluid (SBF). The apatite formation on the carbon-PEEK composite was compared with that of pure PEEK. Both pure PEEK and carbon-PEEK composite formed the apatite in SBF when they were treated with H 2 SO 4 and CaCl 2 ; the latter showed higher apatite-forming ability than the former. It is conjectured that many functional groups able to induce the apatite nucleation, such as sulfo and carboxyl groups, are incorporated into the dispersed carbon phase in the carbon-PEEK composites. Copyright © 2016 Elsevier B.V. All rights reserved.

Energetic composites and method of providing chemical energy

DOEpatents

Danen, Wayne C.; Martin, Joe A.

1997-01-01

A method for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application.

Energetic composites and method of providing chemical energy

DOEpatents

Danen, W.C.; Martin, J.A.

1997-02-25

A method is described for providing chemical energy and energetic compositions of matter consisting of thin layers of substances which will exothermically react with one another. The layers of reactive substances are separated by thin layers of a buffer material which prevents the reactions from taking place until the desired time. The reactions are triggered by an external agent, such as mechanical stress or an electric spark. The compositions are known as metastable interstitial composites (MICs). This class of compositions includes materials which have not previously been capable of use as energetic materials. The speed and products of the reactions can be varied to suit the application. 3 figs.

Carbon dioxide adsorption on micro-mesoporous composite materials of ZSM-12/MCM-48 type: The role of the contents of zeolite and functionalized amine

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

Santos, S.C.G.; Pedrosa, A.M.Garrido; Souza, M.J.B., E-mail: mjbsufs@gmail.com

2015-10-15

Highlights: • Synthesis of the micro-mesoporous composite materials of ZSM-12/MCM-48 type. • Application of these adsorbents in the carbon dioxide adsorption. • Effects of the contents of zeolite and amino group in the material surface on the CO{sub 2} capture efficiency. - Abstract: In this study ZSM-12/MCM-48 adsorbents have been synthesized at three ZSM-12 content, and also were functionalizated with amine groups by grafting. All the adsorbents synthesized were evaluated for CO{sub 2} capture. The X-ray diffraction analysis of the ZSM-12/MCM-48 composite showed the main characteristic peaks of ZSM-12 and MCM-48, and after the functionalization, the structure of MCM-48 onmore » the composite impregnated was affected due amine presence. For the composites without amine, the ZSM-12 content was the factor determining in the adsorption capacity of CO{sub 2} and for the composites with amine the amount of amine was that influenced in the adsorption capacity.« less

Effects of intra- and inter-laminar resin content on the mechanical properties of toughened composite materials

NASA Technical Reports Server (NTRS)

Grande, Dodd H.; Ilcewicz, Larry B.; Avery, William B.; Bascom, Willard D.

1991-01-01

Composite materials having multiphase toughened matrix systems and laminate architectures characterized by resin-rich interlaminar layers (RIL) have been the subject of much recent attention. Such materials are likely to find applications in thick compressively loaded structures such as the keel area of commercial aircraft fuselages. The effects of resin content and its interlaminar and intralaminar distribution on mechanical properties were investigated with test and analysis of two carbon-epoxy systems. The RIL was found to reduce the in situ strengthening effect for matrix cracking in laminates. Mode 2 fracture toughness was found to increase with increasing RIL thickness over the range investigated, and Mode 1 interlaminar toughness was negligibly affected. Compressive failure strains were found to increase with increasing resin content for specimens having no damage, holes, and impact damage. Analytical tools for predicting matrix cracking of off-axis plies and damage tolerance in compression after impact (CAI) were successfully applied to materials with RIL.

Fungal community composition in soils subjected to long-term chemical fertilization is most influenced by the type of organic matter.

PubMed

Sun, Ruibo; Dsouza, Melissa; Gilbert, Jack A; Guo, Xisheng; Wang, Daozhong; Guo, Zhibin; Ni, Yingying; Chu, Haiyan

2016-12-01

Organic matter application is a widely used practice to increase soil carbon content and maintain soil fertility. However, little is known about the effect of different types of organic matter, or the input of exogenous species from these materials, on soil fungal communities. In this study, fungal community composition was characterized from soils amended with three types of organic matter over a 30-year fertilization experiment. Chemical fertilization significantly changed soil fungal community composition and structure, which was exacerbated by the addition of organic matter, with the direction of change influenced by the type of organic matter used. The addition of organic matter significantly increased soil fungal richness, with the greatest richness achieved in soils amended with pig manure. Importantly, following addition of cow and pig manure, fungal taxa associated with these materials could be found in the soil, suggesting that these exogenous species can augment soil fungal composition. Moreover, the addition of organic matter decreased the relative abundance of potential pathogenic fungi. Overall, these results indicate that organic matter addition influences the composition and structure of soil fungal communities in predictable ways. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

SiC-Based Composite Materials Obtained by Siliconizing Carbon Matrices

NASA Astrophysics Data System (ADS)

Shikunov, S. L.; Kurlov, V. N.

2017-12-01

We have developed a method for fabrication of parts of complicated configuration from composite materials based on SiC ceramics, which employs the interaction of silicon melt with the carbon matrix having a certain composition and porosity. For elevating the operating temperatures of ceramic components, we have developed a method for depositing protective silicon-carbide coatings that is based on the interaction of the silicon melt and vapor with carbon obtained during thermal splitting of hydrocarbon molecules. The new structural ceramics are characterized by higher operating temperatures; chemical stability; mechanical strength; thermal shock, wear and radiation resistance; and parameters stability.

Composite materials for thermal energy storage: enhancing performance through microstructures.

PubMed

Ge, Zhiwei; Ye, Feng; Ding, Yulong

2014-05-01

Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical Composition of Salmon Ovary Outer Membrane and Its Protein Increases Fecal Mucins Content in C57BL/6J and Type 2 Diabetic/Obese KK-Ay Mice

PubMed Central

Maeda, Hayato; Hosomi, Ryota; Chiba, Utako; Fukunaga, Kenji

2013-01-01

Salmon ovary outer membrane (SOM) is a byproduct of the salmon industry; however, the effective utilization of SOM for food materials and supplements is anticipated as the demand for fish and seafood increases worldwide. The purposes of the present study were to assess the chemical composition of SOM, the characteristics of SOM protein (SOMP), and its effects on serum and fecal biochemical parameters in mice. SOM contained high levels of crude protein (61.9 g/100 g) and crude lipid (18.9 g/100 g). The protein pattern of SOMP was different from those of fish muscle protein and roe; it was abundant in collagen, as calculated from the hydroxyproline content. In addition, SOMP exhibited lower protein digestibility during in vitro digestion analyses compared with casein. Male C57BL/6J and KK-Ay mice were fed a casein-based semi-purified diet or a diet with replacement of part of the dietary protein (50%) by SOMP for four weeks. Mice fed the diet containing SOMP showed elevated fecal nitrogen and mucins contents and reduced levels of serum liver injury markers and fecal ammonia. These results show for the first time that chemical composition of SOM, and SOMP, contain a resistant protein fraction and a large amount of collagen. Therefore, SOM is a potential source of marine collagen and functional food material for promoting the health of the liver and colon. PMID:28239126

Micro energy-dispersive X-ray fluoresence mapping of enamel and dental materials after chemical erosion.

PubMed

Soares, Luís Eduardo Silva; de Oliveira, Rodrigo; Nahórny, Sídnei; Santo, Ana Maria do Espírito; Martin, Airton Abrahão

2012-10-01

Energy-dispersive X-ray fluorescence was employed to test the hypothesis that beverage consumption or mouthwash utilization will change the chemical properties of dental materials and enamel mineral content. Bovine enamel samples (n = 45) each received two cavity preparations (n = 90), each pair filled with one of three dental materials (R: nanofilled composite resin; GIC: glass-ionomer cement; RMGIC: resin-modified GIC). Furthermore, they were treated with three different solutions (S: saliva; E: erosion/Pepsi Twist®; or EM: erosion+mouthwash/Colgate Plax®). It was found that mineral loss in enamel was greater in GICE samples than in RE > RMGICE > RMGICEM > REM > GICEM. An increased percentage of Zr was found in REM indicating organic matrix degradation. Dental materials tested (R, GIC, and RMGIC) were not able to protect adjacent enamel from acid erosion by the soft drink tested. The use of mouthwash promoted protection of enamel after erosion by the soft drink. To avoid chemical dissolution by mouthwashes, protection by resin composites with surface sealants is recommended.

Study of morphology, chemical, and amino acid composition of red deer meat.

PubMed

Okuskhanova, Eleonora; Assenova, Bahytkul; Rebezov, Maksim; Amirkhanov, Kumarbek; Yessimbekov, Zhanibek; Smolnikova, Farida; Nurgazezova, Almagul; Nurymkhan, Gulnur; Stuart, Marilyne

2017-06-01

The aim of this study was to evaluate red deer (maral) meat quality based on chemical composition, pH, water-binding capacity (WBC), and amino acid content. Maral meat surface morphology measurements were obtained by scanning electron microscopy. Active acidity (pH) was determined by potentiometry. Samples were analyzed for WBC by exudation of moisture to a filter paper by the application of pressure. Chemical composition (moisture, protein, fat, and ash fractions) was obtained by drying at 150°C and by extraction, using ethylic ether, and ashing at 500-600°C. The amino acid composition was obtained by liquid chromatography. Maral meat, with a pH of 5.85 and an average moisture content of 76.82%, was found to be low in fat (2.26%). Its protein content was 18.71% while its ash content was 2.21%. The amino acid composition showed that lysine (9.85 g/100 g), threonine (5.38 g/100 g), and valine (5.84 g/100 g) predominated in maral meat, while phenylalanine (4.08 g/100 g), methionine (3.29 g/100 g), and tryptophan (0.94 g/100 g) were relatively low in maral meat compared to other meats. The average WBC was found to be 65.82% and WBC was found to inversely correlate with moisture content. Low-fat content, high mineral content, and balanced amino-acid composition qualify maral meat as a worthy dietary and functional food.

Study on the chemical composition features of Longquan celadon excavated from the Chuzhou site of Huai'an City in Jiangsu Province by EDXRF

NASA Astrophysics Data System (ADS)

Li, Li; Feng, Song-Lin; Feng, Xiang-Qian; Xu, Qing; Yan, Ling-Tong; Ma, Bo; Huo, Hua

2011-07-01

A mass of Longquan celadon shards were excavated from the Chuzhou site of Huai'an City in Jiangsu Province, China. These celadon shards were fired during the period of the Late Yuan Dynasty to the Tianshun era of the Ming Dynasty, as identified by archaeologists at Nanjing Museum. In order to research the chemical composition features of this ancient celadon porcelain, energy dispersive X-ray fluorescence (EDXRF) for non-destructive analysis was used to determine the chemical composition of the porcelain body and glaze in these shards. The results indicate that Ti and Fe in the body of Longquan celadon are characteristic elements which can distinguish porcelain produced during the Late Yuan Dynasty from those produced in the Ming Dynasties. The results of the principal component analysis (PCA) show that different body and glaze raw materials were used for the production of porcelain in different periods and the raw materials of the body and glaze are also different for various vessel shapes. The chemical compositions in the porcelain body of civilian ware are slightly different. The imperial and civilian Longquan celadon porcelains produced during the Hongwu era to the Tianshun era of the Ming Dynasty are distinguishable by the MnO, Fe2O3, Rb2O and SrO content in their porcelain glaze.

Nutrient composition, digestible and metabolizable energy content, and prediction of energy for animal protein by-products in finishing pig diets

USDA-ARS?s Scientific Manuscript database

An industry survey and an animal experiment were conducted to evaluate compositional variability and DE and ME content of animal protein by-products, and to generate equations to predict DE and ME content based on chemical analysis. For the 220 samples collected, the greatest concentration of CP was...

Enhancement of Thermoelectric Properties of PEDOT:PSS and Tellurium-PEDOT:PSS Hybrid Composites by Simple Chemical Treatment

PubMed Central

Jin Bae, Eun; Hun Kang, Young; Jang, Kwang-Suk; Yun Cho, Song

2016-01-01

The thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and tellurium-PEDOT:PSS (Te-PEDOT:PSS) hybrid composites were enhanced via simple chemical treatment. The performance of thermoelectric materials is determined by their electrical conductivity, thermal conductivity, and Seebeck coefficient. Significant enhancement of the electrical conductivity of PEDOT:PSS and Te-PEDOT:PSS hybrid composites from 787.99 and 11.01 to 4839.92 and 334.68 S cm−1, respectively was achieved by simple chemical treatment with H2SO4. The power factor of the developed materials could be effectively tuned over a very wide range depending on the concentration of the H2SO4 solution used in the chemical treatment. The power factors of the developed thermoelectric materials were optimized to 51.85 and 284 μW m−1 K−2, respectively, which represent an increase of four orders of magnitude relative to the corresponding parameters of the untreated thermoelectric materials. Using the Te-PEDOT:PSS hybrid composites, a flexible thermoelectric generator that could be embedded in textiles was fabricated by a printing process. This thermoelectric array generates a thermoelectric voltage of 2 mV using human body heat. PMID:26728992

Effect of soaking in water and rumen digeta solutions on metabolizable energy content and chemical composition of barley seeds for use in poultry diet.

PubMed

Tabatabee, S N; Sadeghi, G H; Tabeidian, S A

2007-03-15

An experiment was carried out to evaluate the effect of soaking in water and different rumen digesta solutions on nutritional value of dry barley seeds. Treatments were included distilled water as control and rumen digesta that diluted with distilled water to obtain 20, 40 and 60% digesta solutions. Solutions have added to 10 kg of barley seed samples to achieve final 30% moisture content. After 21 days the chemical composition and energy content of barley seed were determined. Gross energy of barley seeds did not affected by different experimental treatments. Use of 20% rumen digesta solution resulted to a significant (p<0.01) increase in AME and AMEn content of barley seeds. Barley seed that treated with 40% of rumen digesta solution had highest TME and TMEn content and its different from seeds that treated with 60 and 100% rumen digesta solutions was significant (p<0.05). The chemical composition such as dry matter, crud protein, crude fat, crud fiber, ash and NFE were found to be similar and there was no significant difference. However, soaking in rumen digesta solutions increased crud protein, ether extract, crude fiber and ash content of barley seeds numerically.

Composite material and method of making

DOEpatents

Fryxell, Glen E.; Samuels, William D.; Simmons, Kevin L.

2004-04-20

The composite material and methods of making the present invention rely upon a fully dense monolayer of molecules attached to an oxygenated surface at one end, and an organic terminal group at the other end, which is in turn bonded to a polymer. Thus, the composite material is a second material chemically bonded to a polymer with fully dense monolayer there between.

Controlled optical properties via chemical composition tuning in molybdenum-incorporated β-Ga2O3 nanocrystalline films

NASA Astrophysics Data System (ADS)

Battu, Anil K.; Manandhar, S.; Shutthanandan, V.; Ramana, C. V.

2017-09-01

An approach is presented to design refractory-metal incorporated Ga2O3-based materials with controlled structural and optical properties. The molybdenum (Mo)-content in Ga2O3 was varied from 0 to 11 at% in the sputter-deposited Ga-Mo-O films. Molybdenum was found to significantly affect the structure and optical properties. While low Mo-content (≤4 at%) results in the formation of single-phase (β-Ga2O3), higher Mo-content results in amorphization. Chemically-induced band gap variability (Eg ∼ 1 eV) coupled with structure-modification indicates the electronic-structure changes in Ga-Mo-O. The linear relationship between chemical-composition and optical properties suggests that tailoring the optical-quality and performance of Ga-Mo-O films is possible by tuning the Mo-content.

Controlled optical properties via chemical composition tuning in molybdenum-incorporated β-Ga 2 O 3 nanocrystalline films

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

Battu, Anil K.; Manandhar, S.; Shutthanandan, V.

An approach is presented to design refractory-metal incorporated Ga2O3-based materials with controlled structural and optical properties. The molybdenum (Mo)-content in Ga2O3 was varied from 0 to 11 at% in the sputter-deposited Ga-Mo-O films. Molybdenum was found to significantly affect the structure and optical properties. While low Mo-content (≤4 at%) results in the formation of single-phase (β-Ga2O3), higher Mo-content results in amorphization. Chemically-induced band gap variability (Eg~1 eV) coupled with structure-modification indicates the electronic-structure changes in Ga-Mo-O. The linear relationship between chemical-composition and optical properties suggests that tailoring the optical-quality and performance of Ga-Mo-O films is possible by tuning the Mo-content.

Radon diffusion coefficients in 360 waterproof materials of different chemical composition.

PubMed

Jiránek, M; Kotrbatá, M

2011-05-01

This paper summarises the results of radon diffusion coefficient measurements in 360 common waterproof materials available throughout Europe. The materials were grouped into 26 categories according to their chemical composition. It was found that the diffusion coefficients of materials used for protecting houses against radon vary within eight orders from 10(-15) to 10(-8) m(2) s(-1). The lowest values were obtained for bitumen membranes with an Al carrier film and for ethylene vinyl acetate membranes. The highest radon diffusion coefficient values were discovered for sodium bentonite membranes, rubber membranes made of ethylene propylene diene monomer and polymer cement coatings. The radon diffusion coefficients for waterproofings widely used for protecting houses, i.e. flexible polyvinyl chloride, high-, low-density polyethylene, polypropylene and bitumen membranes, vary in the range from 3 × 10(-12) to 3 × 10(-11) m(2) s(-1). Tests were performed which confirmed that the radon diffusion coefficient is also an effective tool for verifying the air-tightness of joints.

Environmental and Chemical Aging of Fatty-Acid-Based Vinyl Ester Composites

DTIC Science & Technology

2011-04-01

Environmental and Chemical Aging of Fatty- Acid -Based Vinyl Ester Composites by Steven E. Boyd and John J. La Scala ARL-TR-5523 April...2011 Environmental and Chemical Aging of Fatty- Acid -Based Vinyl Ester Composites Steven E. Boyd and John J. La Scala Weapons and Materials...COVERED (From - To) October 2009–September 2010 4. TITLE AND SUBTITLE Environmental and Chemical Aging of Fatty- Acid -Based Vinyl Ester Composites

The effects of space radiation on a chemically modified graphite-epoxy composite material

NASA Technical Reports Server (NTRS)

Reed, S. M.; Herakovich, C. T.; Sykes, G. F.

1986-01-01

The effects of the space environment on the engineering properties and chemistry of a chemically modified T300/934 graphite-epoxy composite system are characterized. The material was subjected to 1.0 x 10 to the 10th power rads of 1.0 MeV electron irradiation under vacuum to simulate 30 years in geosynchronous earth orbit. Monotonic tension tests were performed at room temperature (75 F/24 C) and elevated temperature (250 F/121 C) on 4-ply unidirectional laminates. From these tests, inplane engineering and strength properties (E sub 1, E sub 2, Nu sub 12, G sub 12, X sub T, Y sub T) were determined. Cyclic tests were also performed to characterize energy dissipation changes due to irradiation and elevated temperature. Large diameter graphite fibers were tested to determine the effects of radiation on their stiffness and strength. No significant changes were observed. Dynamic-mechanical analysis demonstrated that the glass transition temperature was reduced by 50 F(28 C) after irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated material. The chemical modification of the epoxy did not aid in producing a material which was more radiation resistant than the standard T300/934 graphite-epoxy system. Irradiation was found to cause crosslinking and chain scission in the polymer. The latter produced low molecular weight products which plasticize the material at elevated temperatures and cause apparent material stiffening at low stresses at room temperature.

Vector diagram of the chemical compositions of tektites and earth lavas

NASA Technical Reports Server (NTRS)

Kvasha, L. G.; Gorshkov, G. S.

1978-01-01

The chemical compositions of tektites and various volcanic glasses, similar in composition to tektites are compared by a petrochemical method. The advantage of the method is that a large number of chemical analyses of igneous rocks can be graphically compared with the help of vectors, plotted in relation to six parameters. These parameters, calculated from ratios of the main oxides given by silicate analysis, reflect the chief characteristics of igneous rock. Material for the study was suppled by data from chemical analysis characterizing tektites of all known locations and data from chemical analyses of obsidians similar in chemical composition to tektites of various petrographical provinces.

Experimental Study on Impact-Induced Reaction Characteristics of PTFE/Ti Composites Enhanced by W Particles.

PubMed

Li, Yan; Wang, Zaicheng; Jiang, Chunlan; Niu, Haohao

2017-02-13

Metal/fluoropolymer composites are a category of energetic structural materials that release energy through exothermic chemical reactions initiated under highly dynamic loadings. In this paper, the chemical reaction mechanism of PTFE (polytetrafluoroethylene)/Ti/W composites is investigated through thermal analysis and composition analysis. These composites undergo exothermic reactions at 510 °C to 600 °C, mainly producing TiF x . The tungsten significantly reduces the reaction heat due to its inertness. In addition, the dynamic compression properties and impact-induced reaction behaviors of PTFE/Ti/W composites with different W content prepared by pressing and sintering are studied using Split Hopkinson Pressure Bar and high speed photography. The results show that both the mechanical strength and the reaction degree are significantly improved with the increasing strain rate. Moreover, as W content increases, the mechanical strength is enhanced, but the elasticity/plasticity is decreased. The PTFE/Ti/W composites tend to become more inert with the increasing W content, which is reflected by the reduced reaction degree and the increased reaction threshold for the impact ignition.

Experimental Study on Impact-Induced Reaction Characteristics of PTFE/Ti Composites Enhanced by W Particles

PubMed Central

Li, Yan; Wang, Zaicheng; Jiang, Chunlan; Niu, Haohao

2017-01-01

Metal/fluoropolymer composites are a category of energetic structural materials that release energy through exothermic chemical reactions initiated under highly dynamic loadings. In this paper, the chemical reaction mechanism of PTFE (polytetrafluoroethylene)/Ti/W composites is investigated through thermal analysis and composition analysis. These composites undergo exothermic reactions at 510 °C to 600 °C, mainly producing TiFx. The tungsten significantly reduces the reaction heat due to its inertness. In addition, the dynamic compression properties and impact-induced reaction behaviors of PTFE/Ti/W composites with different W content prepared by pressing and sintering are studied using Split Hopkinson Pressure Bar and high speed photography. The results show that both the mechanical strength and the reaction degree are significantly improved with the increasing strain rate. Moreover, as W content increases, the mechanical strength is enhanced, but the elasticity/plasticity is decreased. The PTFE/Ti/W composites tend to become more inert with the increasing W content, which is reflected by the reduced reaction degree and the increased reaction threshold for the impact ignition. PMID:28772534

Influence of Bulk Chemical Composition on Relative Sensitivity Factors for 55Mn/52Cr by SIMS: Implications for the 53Mn-53Cr Chronometer

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

Matzel, J; Jacobsen, B; Hutcheon, I D

2009-09-09

The {sup 53}Mn-{sup 53}Cr systematics of meteorite samples provide an important high resolution chronometer for early solar system events. Accurate determination of the initial abundance of {sup 53}Mn ({tau}{sub 1/2} = 3.7 Ma) by secondary ion mass spectrometry (SIMS) is dependent on properly correcting for differing ion yields between Mn and Cr by use of a relative sensitivity factor (RSF). Ideal standards for SIMS analysis should be compositionally and structurally similar to the sample of interest. However, previously published Mn-Cr studies rely on few standards (e.g., San Carlos olivine, NIST 610 glass) despite significant variations in chemical composition. We investigatemore » a potential correlation between RSF and bulk chemical composition by determining RSFs for {sup 55}Mn/{sup 52}Cr in 11 silicate glass and mineral standards (San Carlos olivine, Mainz glasses KL2-G, ML3B-G, StHs6/80-G, GOR128-G, BM90/21-G, and T1-G, NIST 610 glass, and three LLNL pyroxene-composition glasses). All standards were measured on the Cameca ims-3f ion microprobe at LLNL, and a subset were also measured on the Cameca ims-1270 ion microprobe at the Geological Survey of Japan. The standards cover a range of bulk chemical compositions with SiO{sub 2} contents of 40-71 wt.%, FeO contents of 0.05-20 wt.% and Mn/Cr ratios between 0.4 and 58. We obtained RSF values ranging from 0.83 to 1.15. The data obtained on the ims-1270 ion microprobe are within {approx}10% of the RSF values obtained on the ims-3f ion microprobe, and the RSF determined for San Carlos olivine (0.86) is in good agreement with previously published data. The typical approach to calculating an RSF from multiple standard measurements involves making a linear fit to measured {sup 55}Mn/{sup 52}Cr versus true {sup 55}Mn/{sup 52}Cr. This approach may be satisfactory for materials of similar composition, but fails when compositions vary significantly. This is best illustrated by the {approx}30% change in RSF we see

Composite structural materials

NASA Technical Reports Server (NTRS)

Loewy, Robert G.; Wiberley, Stephen E.

1987-01-01

The development and application of composite materials to aerospace vehicle structures which began in the mid 1960's has now progressed to the point where what can be considered entire airframes are being designed and built using composites. Issues related to the fabrication of non-resin matrix composites and the micro, mezzo and macromechanics of thermoplastic and metal matrix composites are emphasized. Several research efforts are presented. They are entitled: (1) The effects of chemical vapor deposition and thermal treatments on the properties of pitch-based carbon fiber; (2) Inelastic deformation of metal matrix laminates; (3) Analysis of fatigue damage in fibrous MMC laminates; (4) Delamination fracture toughness in thermoplastic matrix composites; (5) Numerical investigation of the microhardness of composite fracture; and (6) General beam theory for composite structures.

Proximate and fatty acid composition and cholesterol content of different cuts of guinea fowl meat as affected by cooking method.

PubMed

Hoffman, Louwrens C; Tlhong, Tumelo M

2012-10-01

Poultry is one of the leading meat products in South Africa, and its nutritional composition can be affected by the cut and cooking method. Limited food composition data are available for typical South African poultry products. This study investigated the effect of different cuts and cooking methods on the proximate and fatty acid composition as well as the cholesterol content of guinea fowl (Numida meleagris) meat. The open-roasting method produced the highest moisture content for all cuts, and the baking bag method the lowest. The baking bag method resulted in the highest protein content. Cooking method had no effect on fat content, although breast had the lowest and thigh the highest fat content. Ash content was highest in the open-roasted drumstick. All cuts, regardless of cooking method, had a favourable polyunsaturated/saturated fatty acid (P/S) ratio (>0.4). Their n-6/n-3 ratio was also within the recommended beneficial range (<4:1). Both cooking method and cut affected cholesterol content. Different cuts of guinea fowl vary in proximate and fatty acid composition as well as in cholesterol content, which in turn is affected to varying degrees by cooking method. Copyright © 2012 Society of Chemical Industry.

Highly birefringent polymer microstructured optical fibers embedded in composite materials

NASA Astrophysics Data System (ADS)

Lesiak, P.; SzelÄ g, M.; Kuczkowski, M.; Domański, A. W.; Woliński, T. R.

2013-05-01

Composite structures are made from two or more constituent materials with significantly different physical or chemical properties and they remain separate and distinct in a macroscopic level within the finished structure. This feature allows for introducing highly birefringent polymer microstructured optical fibers into the composite material. These new fibers can consist of only two polymer materials (PMMA and PC) with similar value of the Young modulus as the composite material so any stresses induced in the composite material can be easily measured by the proposed embedded fiber optic sensors.

Flame-Resistant Composite Materials For Structural Members

NASA Technical Reports Server (NTRS)

Spears, Richard K.

1995-01-01

Matrix-fiber composite materials developed for structural members occasionally exposed to hot, corrosive gases. Integral ceramic fabric surface layer essential for resistance to flames and chemicals. Endures high temperature, impedes flame from penetrating to interior, inhibits diffusion of oxygen to interior where it degrades matrix resin, resists attack by chemicals, helps resist erosion, and provides additional strength. In original intended application, composite members replace steel structural members of rocket-launching structures that deteriorate under combined influences of atmosphere, spilled propellants, and rocket exhaust. Composites also attractive for other applications in which corrosion- and fire-resistant structural members needed.

Controlled optical properties via chemical composition tuning in molybdenum-incorporated β-Ga 2O 3 nanocrystalline films

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

Battu, Anil K.; Manandhar, S.; Shutthanandan, V.

Here, an approach is presented to design refractory-metal incorporated Ga 2O 3-based materials with controlled structural and optical properties. The molybdenum (Mo)-content in Ga 2O 3 was varied from 0 to 11 at% in the sputter-deposited Ga-Mo-O films. Molybdenum was found to significantly affect the structure and optical properties. While low Mo-content (≤4 at%) results in the formation of single-phase (β-Ga 2O 3), higher Mo-content results in amorphization. Chemically-induced band gap variability (E g ~ 1 eV) coupled with structure-modification indicates the electronic-structure changes in Ga-Mo-O. The linear relationship between chemical-composition and optical properties suggests that tailoring the optical-quality andmore » performance of Ga-Mo-O films is possible by tuning the Mo-content.« less

Controlled optical properties via chemical composition tuning in molybdenum-incorporated β-Ga 2O 3 nanocrystalline films

DOE PAGES

Battu, Anil K.; Manandhar, S.; Shutthanandan, V.; ...

2017-07-01

Here, an approach is presented to design refractory-metal incorporated Ga 2O 3-based materials with controlled structural and optical properties. The molybdenum (Mo)-content in Ga 2O 3 was varied from 0 to 11 at% in the sputter-deposited Ga-Mo-O films. Molybdenum was found to significantly affect the structure and optical properties. While low Mo-content (≤4 at%) results in the formation of single-phase (β-Ga 2O 3), higher Mo-content results in amorphization. Chemically-induced band gap variability (E g ~ 1 eV) coupled with structure-modification indicates the electronic-structure changes in Ga-Mo-O. The linear relationship between chemical-composition and optical properties suggests that tailoring the optical-quality andmore » performance of Ga-Mo-O films is possible by tuning the Mo-content.« less

Graphene-based composite materials.

PubMed

Stankovich, Sasha; Dikin, Dmitriy A; Dommett, Geoffrey H B; Kohlhaas, Kevin M; Zimney, Eric J; Stach, Eric A; Piner, Richard D; Nguyen, SonBinh T; Ruoff, Rodney S

2006-07-20

Graphene sheets--one-atom-thick two-dimensional layers of sp2-bonded carbon--are predicted to have a range of unusual properties. Their thermal conductivity and mechanical stiffness may rival the remarkable in-plane values for graphite (approximately 3,000 W m(-1) K(-1) and 1,060 GPa, respectively); their fracture strength should be comparable to that of carbon nanotubes for similar types of defects; and recent studies have shown that individual graphene sheets have extraordinary electronic transport properties. One possible route to harnessing these properties for applications would be to incorporate graphene sheets in a composite material. The manufacturing of such composites requires not only that graphene sheets be produced on a sufficient scale but that they also be incorporated, and homogeneously distributed, into various matrices. Graphite, inexpensive and available in large quantity, unfortunately does not readily exfoliate to yield individual graphene sheets. Here we present a general approach for the preparation of graphene-polymer composites via complete exfoliation of graphite and molecular-level dispersion of individual, chemically modified graphene sheets within polymer hosts. A polystyrene-graphene composite formed by this route exhibits a percolation threshold of approximately 0.1 volume per cent for room-temperature electrical conductivity, the lowest reported value for any carbon-based composite except for those involving carbon nanotubes; at only 1 volume per cent, this composite has a conductivity of approximately 0.1 S m(-1), sufficient for many electrical applications. Our bottom-up chemical approach of tuning the graphene sheet properties provides a path to a broad new class of graphene-based materials and their use in a variety of applications.

Laser-induced breakdown spectroscopy (LIBS) technique for the determination of the chemical composition of complex inorganic materials

NASA Astrophysics Data System (ADS)

Łazarek, Łukasz; Antończak, Arkadiusz J.; Wójcik, Michał R.; Kozioł, Paweł E.; Stepak, Bogusz; Abramski, Krzysztof M.

2014-08-01

Laser-induced breakdown spectroscopy (LIBS) is a fast, fully optical method, that needs little or no sample preparation. In this technique qualitative and quantitative analysis is based on comparison. The determination of composition is generally based on the construction of a calibration curve namely the LIBS signal versus the concentration of the analyte. Typically, to calibrate the system, certified reference materials with known elemental composition are used. Nevertheless, such samples due to differences in the overall composition with respect to the used complex inorganic materials can influence significantly on the accuracy. There are also some intermediate factors which can cause imprecision in measurements, such as optical absorption, surface structure, thermal conductivity etc. This paper presents the calibration procedure performed with especially prepared pellets from the tested materials, which composition was previously defined. We also proposed methods of post-processing which allowed for mitigation of the matrix effects and for a reliable and accurate analysis. This technique was implemented for determination of trace elements in industrial copper concentrates standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for contents of three elements, that is silver, cobalt and vanadium. It has been shown that the described technique can be used to qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates.

NASA technology utilization survey on composite materials

NASA Technical Reports Server (NTRS)

Leeds, M. A.; Schwartz, S.; Holm, G. J.; Krainess, A. M.; Wykes, D. M.; Delzell, M. T.; Veazie, W. H., Jr.

1972-01-01

NASA and NASA-funded contractor contributions to the field of composite materials are surveyed. Existing and potential non-aerospace applications of the newer composite materials are emphasized. Economic factors for selection of a composite for a particular application are weight savings, performance (high strength, high elastic modulus, low coefficient of expansion, heat resistance, corrosion resistance,), longer service life, and reduced maintenance. Applications for composites in agriculture, chemical and petrochemical industries, construction, consumer goods, machinery, power generation and distribution, transportation, biomedicine, and safety are presented. With the continuing trend toward further cost reductions, composites warrant consideration in a wide range of non-aerospace applications. Composite materials discussed include filamentary reinforced materials, laminates, multiphase alloys, solid multiphase lubricants, and multiphase ceramics. New processes developed to aid in fabrication of composites are given.

Average chemical composition of the lunar surface

NASA Technical Reports Server (NTRS)

Turkevich, A. L.

1973-01-01

The available data on the chemical composition of the lunar surface at eleven sites (3 Surveyor, 5 Apollo and 3 Luna) are used to estimate the amounts of principal chemical elements (those present in more than about 0.5% by atom) in average lunar surface material. The terrae of the moon differ from the maria in having much less iron and titanium and appreciably more aluminum and calcium.

Wastewater characterisation by combining size fractionation, chemical composition and biodegradability.

PubMed

Ravndal, Kristin T; Opsahl, Eystein; Bagi, Andrea; Kommedal, Roald

2017-12-18

The potential for resource recovery from wastewater can be evaluated based on a detailed characterisation of wastewater. In this paper, results from fractionation and characterisation of two distinct wastewaters are reported. Using tangential flow filtration, the wastewater was fractionated into 10 size fractions ranging from 1 kDa to 1 mm, wherein the chemical composition and biodegradability were determined. Carbohydrates were dominant in particulate size fractions larger than 100 μm, indicating a potential of cellulose recovery from these fractions. While the particulate size fractions between 0.65 and 100 μm show a potential as a source for biofuel production due to an abundance of saturated C16 and C18 lipids. Both wastewaters were dominated by particulate (>0.65 μm), and oligo- and monomeric (<1 kDa) COD. Polymeric (1-1000 kDa) and colloidal (1000 kDa-0.65 μm) fractions had a low COD content, expected due to degradation in the sewer system upstream of the wastewater treatment plant. Biodegradation rates of particulate fractions increase with decreasing size. However, this was not seen in polymeric fractions where degradation rate was governed by chemical composition. Analytical validation of molecular weight and particle size distribution showed below filter cut-off retention of particles and polymers close to nominal cut-off, shifting the actual size distribution. Copyright © 2017. Published by Elsevier Ltd.

A composite material based on recycled tires

NASA Astrophysics Data System (ADS)

Malers, L.; Plesuma, R.; Locmele, L.

2009-01-01

The present study is devoted to the elaboration and investigation of a composite material based on mechanically grinded recycled tires and a polymer binder. The correlation between the content of the binder, some technological parameters, and material properties of the composite was clarified. The apparent density, the compressive stress at a 10% strain, the compressive elastic modulus in static and cyclic loadings, and the insulating properties (acoustic and thermal) were the parameters of special interest of the present investigation. It is found that a purposeful variation of material composition and some technological parameters leads to multifunctional composite materials with different and predictable mechanical and insulation properties.

Combinatorial synthesis of inorganic or composite materials

DOEpatents

Goldwasser, Isy; Ross, Debra A.; Schultz, Peter G.; Xiang, Xiao-Dong; Briceno, Gabriel; Sun, Xian-Dong; Wang, Kai-An

2010-08-03

Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials or, alternatively, allowing the components to interact to form at least two different materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, nonbiological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

Review on effect of chemical, thermal, additive treatment on mechanical properties of basalt fiber and their composites

NASA Astrophysics Data System (ADS)

Jain, Naman; Singh, Vinay Kumar; Chauhan, Sakshi

2017-12-01

Basalt fiber is emerging out the new reinforcing material for composites. To overcome some of the disadvantages of fibers such as poor bonding to polymers, low thermal stability and high moisture absorption fiber characteristics are modified with chemical, thermal and additive treatments. Chemical treatment corrosive resistance to alkali and acid were investigated which were used to clean and modify the surface of fiber for higher bonding with resins. To improve the thermal stability and reduce moisture uptake thermal treatment such as plasma and non thermal plasma were used which increased the surface roughness and change the chemical composition of surface of basalt fiber. Additive treatment is used to improve the mechanical properties of fibers, in basalt fiber additive treatment was done with SiO2 additive because of its chemical composition which contains major content of SiO2. In present investigation review on the effect of different treatment such as chemical, thermal and additive were studied. Effect of these treatment on chemical composition of the surface of basalt fiber and corrosion to acidic and alkali solution were studied with their effect on mechanical properties of basalt fiber and their composite.

[Chemical composition and content of antiphysiological factors of jojoba (Simmondsia chinensis) residual meal].

PubMed

Pérez-Gil, F; Sanginés, G L; Torreblanca, R A; Grande, M L; Carranco, J M

1989-12-01

Jojoba (Simmondsia chinensis) is a perennial plant with an interesting economic value by processing it for liquid wax production. By pressing of jojoba seeds, by-product which has been called "residual meal" has been obtained, and because of its high protein content, it would be a great interest to evaluate it as animal feedstuff. The results of this study showed the following. Both seed and residual meal were analyzed in regard to their chemical proximal composition: crude protein 14.03 and 25.24%; ether extract, 48.89 and 14.73%; crude fiber, 10.03 and 10.07%; ash, 1.59 and 4.72, and nitrogen-free extract, 25.46 and 45.25, the limiting amino acids being methionine, lysine and isoleucine. The trypsin inhibitor factors were 13.747 and 11,197 TIU/g; and hemagglutinins and saponins were negative for both samples. Cyanogenic glucosides were positive in both samples. It was concluded that jojoba residual meal is an alternative as an adequate feedstuff in those regions where jojoba is produced. Nevertheless, prior to consumption it must be treated so as to eliminate the toxic factors.

The effect of filler content and processing variables on dimensional accuracy of experimental composite inlay material.

PubMed

Razak, A A; Harrison, A

1997-04-01

Dimensional accuracy of a composite inlay restoration is important to ensure an accurate fit and to minimize cementation stresses. A method was developed to measure dimensional accuracy and stability of a composite inlay. A standard Class II (MOD) inlay cavity stainless steel mold was made with six circular indentations placed on the occlusal floor of the cavity and four indentations on each gingival floor to act as datum points in the measurement of linear polymerization shrinkage. The inlay restorations were prepared from an inlay-onlay composite material of different filler contents (50%, 65%, and 79% by weight). For each filler content group, three curing methods were used: light curing only, light curing and heat curing at 100 degrees C for 5 minutes, and light curing and heat curing at 100 degrees C for 5 minutes and then storage in distilled water for 7 days. The accuracy of the MOD inlays was determined by measuring the shrinkage of the restoration on the occlusal floor areas and the gingival seats. The results demonstrated an inverse linear relationship between filler content and polymerization shrinkage. There was a tendency for the light-curing and heat-curing method to show an increase in polymerization shrinkage. An expansion was recorded between the mesial and distal boxes when the specimens were soaked in water for 7 days. This study suggested that the inlay mold limits the physical shrinkage that can occur between the mesial and distal axial walls of the inlay restoration because the inlay cannot shrink to a smaller dimension than the mold. Water sorption then causes hygroscopic expansion, which enlarges the distance between the mesial and distal walls.

Production and evaluation of mineral and nutrient contents, chemical composition, and sensory properties of ice creams fortified with laboratory-prepared peach fibre

PubMed Central

Yangılar, Filiz

2016-01-01

Background In the coming years, a nutraceutical food may provide both physical and mental benefits that are commonly attributed to the active components of the food. Objective In this study, we determined the nutrient and mineral contents, sensory properties, and physical and chemical characteristics of ice creams manufactured using peach fibre at different concentrations (1 and 2%). Method A total of five experimental groups were formed: two types (from peach peel and pulp) of flour, two fibre concentrations (1 and 2%), and a control group without fibres. Results Flour obtained from peach pulp and peel was found to have a significant (p<0.05) effect on the chemical composition and elemental composition of ice cream samples, especially the rates of Ca, K, Mg, and P, which increased in the samples depending on the content of peach fibre. Sensory ratings and acceptability of ice creams decreased significantly with increasing peach peel fibre, whereas ice creams made with C (control) and B1 (ice creams made from 1% peach pulp fibre) was the highest scored by the panellists. Conclusions Peach fibre concentrates might be used as a good source of nutraceutical ingredients. PMID:27814781

Chemical Compositions, Somatic Embryogenesis, and Somaclonal Variation in Cumin

PubMed Central

Tohidfar, Masoud; Sadat Noori, Seyed Ahmad; Izadi Darbandi, Ali; Rao, Rosa

2017-01-01

This is the first report evaluating the relationship between the chemical compositions of cumin seeds (based on the analysis of the content of catalase, ascorbate peroxidase, proline, protein, terpenic compounds, alcohol/phenols, aldehydes, and epoxides) and the induction efficiency of somatic embryogenesis in two Iranian superior cumin landraces (Golestan and North Khorasan). Cotyledons isolated from Golestan landrace seeds cultivated on MS medium supplemented with 0.1 mg/L kinetin proved to be the best primary explant for the induction of somatic embryogenesis as well as the regeneration of the whole plantlet. Results indicated that different developmental stages of somatic embryos were simultaneously observed on a callus with embryogenic potential. The high content of catalase, ascorbate peroxidase, proline, and terpenic hydrocarbons and low content of alcoholic and phenolic compositions had a stimulatory effect on somatic embryogenesis. Band patterns of RAPD markers in regenerated plants were different from those of the mother plants. This may be related to somaclonal variations or pollination system of cumin. Generally, measurement of chemical compositions can be used as a marker for evaluating the occurrence of somatic embryogenesis in cumin. Also, somaclonal variations of regenerated plants can be applied by the plant breeders in breeding programs. PMID:29234682

Modelling of chemical degradation of blended cement-based materials by leaching cycles with Callovo-Oxfordian porewater

NASA Astrophysics Data System (ADS)

Olmeda, Javier; Henocq, Pierre; Giffaut, Eric; Grivé, Mireia

2017-06-01

The present work describes a thermodynamic model based on pore water replacement cycles to simulate the chemical evolution of blended cement (BFS + FA) by interaction with external Callovo-Oxfordian (COx) pore water. In the framework of the radioactive waste management, the characterization of the radionuclide behaviour (solubility/speciation, adsorption) in cementitious materials needs to be done for several chemical degradation states (I to IV). In particular, in the context of the deep geological radioactive waste disposal project (Cigéo), cement-based materials will be chemically evolved with time in contact with the host-rock (COx formation). The objective of this study is to provide an equilibrium solution composition for each degradation state for a CEM-V cement-based material to support the adsorption and diffusion experiments reproducing any state of degradation. Calculations have been performed at 25 °C using the geochemical code PhreeqC and an up-to-date thermodynamic database (ThermoChimie v.9.0.b) coupled to SIT approach for ionic strength correction. The model replicates experimental data with accuracy. The approach followed in this study eases the analysis of the chemical evolution in both aqueous and solid phase to obtain a fast assessment of the geochemical effects associated to an external water intrusion of variable composition on concrete structures.

Estimates of diet selection in cattle grazing cornstalk residues by measurement of chemical composition and near infrared reflectance spectroscopy of diet samples collected by ruminal evacuation.

PubMed

Petzel, Emily A; Smart, Alexander J; St-Pierre, Benoit; Selman, Susan L; Bailey, Eric A; Beck, Erin E; Walker, Julie A; Wright, Cody L; Held, Jeffrey E; Brake, Derek W

2018-05-04

Six ruminally cannulated cows (570 ± 73 kg) fed corn residues were placed in a 6 × 6 Latin square to evaluate predictions of diet composition from ruminally collected diet samples. After complete ruminal evacuation, cows were fed 1-kg meals (dry matter [DM]-basis) containing different combinations of cornstalk and leaf and husk (LH) residues in ratios of 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0. Diet samples from each meal were collected by removal of ruminal contents after 1-h and were either unrinsed, hand-rinsed or machine-rinsed to evaluate effects of endogenous compounds on predictions of diet composition. Diet samples were analyzed for neutral (NDF) and acid (ADF) detergent fiber, acid detergent insoluble ash (ADIA), acid detergent lignin (ADL), crude protein (CP), and near infrared reflectance spectroscopy (NIRS) to calculate diet composition. Rinsing type increased NDF and ADF content and decreased ADIA and CP content of diet samples (P < 0.01). Rinsing tended to increase (P < 0.06) ADL content of diet samples. Differences in concentration between cornstalk and LH residues within each chemical component were standardized by calculating a coefficient of variation (CV). Accuracy and precision of estimates of diet composition were analyzed by regressing predicted diet composition and known diet composition. Predictions of diet composition were improved by increasing differences in concentration of chemical components between cornstalk and LH residues up to a CV of 22.6 ± 5.4%. Predictions of diet composition from unrinsed ADIA and machine-rinsed NIRS had the greatest accuracy (slope = 0.98 and 0.95, respectively) and large coefficients of determination (r2 = 0.86 and 0.74, respectively). Subsequently, a field study (Exp. 2) was performed to evaluate predictions of diet composition in cattle (646 ± 89 kg) grazing corn residue. Five cows were placed in 1 of 10 paddocks and allowed to graze continuously or to strip-graze corn residues. Predictions of diet

Fabrication of a nanostructured gold-polymer composite material.

PubMed

Mallick, K; Witcomb, M; Scurrell, M

2006-07-01

A facile synthesis route is described for the preparation of a poly-(o-aminophenol)-gold nanoparticle composite material by polymerization of o-aminophenol (AP) monomer using HAuCl(4) as the oxidant. The synthesis was carried out in a methanol medium so that it could serve a dual solvent role, a solvent for both the AP and the water solution of HAuCl(4). It was found that oxidative polymerization of AP leads to the formation of poly-AP with a diameter of 50+/-10nm, while the reduction of AuCl(4) (-) results in the formation of gold nanoparticles ( approximately 2nm). The gold nanoparticles were uniformly dispersed and highly stabilized throughout the macromolecular chain that formed a uniform metal-polymer composite material. The resultant composite material was characterized by means of different techniques, such as UV-vis, IR and Raman spectroscopy, which offered the information about the chemical structure of polymer, whereas electron microscopy images provided information regarding the morphology of the composite material and the distribution of the metal particles in the composite material.

Proximate composition and caloric content of eight Lake Michigan fishes

USGS Publications Warehouse

Rottiers, Donald V.; Tucker, Robert M.

1982-01-01

We measured the proximate composition (percentage lipid, water, fat-free dry material, ash) and caloric content of eight species of Lake Michigan fish: lake trout (Salvelinus namaycush), coho salmon (Oncorhynchus kisutch), lake whitefish (Coregonus clupeaformis), bloater (Coregonus hoyi), alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), deepwater sculpin (Myoxocephalus quadricornis), and slimy sculpin (Cottus cognatus). Except for alewives, proximate composition and caloric content did not differ significantly between males and females. And, for coho salmon, there was no significant difference in composition between fish collected in different years. Lipid and caloric content of lake trout increased directly with age. In all species examined, lipids and caloric contents were significantly lower in small, presumably immature, fish than in larger, older fish. Lipid content of lake trout, lake whitefish, and bloaters (range of means, 16-22%) was nearly 3 times higher than that of coho salmon, sculpins, rainbow smelt, and alewives (range of means, 5.2-7.0%). The mean caloric content ranged from 6.9 to 7.1 kcal/g for species high in lipids and from 5.8 to 6.3 kcal/g for species low in lipids. Although the caloric content of all species varied directly with lipid content and inversely with water content, an increase in lipid content did not always coincide with a proportional increase in caloric content when other components of fish composition were essentially unchanged. This observation suggests that the energy content of fish estimated from the proximate composition by using universal conversion factors may not necessarily be accurate.

Chemical and mineralogical characterization of archaeologicam building materials from Seyitomer Hoyuk Kutahya, Turkey.

NASA Astrophysics Data System (ADS)

Bilgen, Nejat; Olgun, Asim

This paper focuses on the spectroscopic and thermal analysis of the archaeological samples of mortar and plaster from middle Bronze Age and Achaemenid period in Seyitömer Höyük. The composition of the samples was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric thermal analysis (TG-DTA). The results showed that human used different types of raw materials in the preperation of the mortar and plaster in the Middle Bronze Age and Achaemenid period. The material used in middle Bronze Age contains muscovite whereas the material in Achaemenid period contains albite. Although, the chemical composition of the mortar and plaster used in the period were similar, the calcium content of the plaster is relatively higher than the one of the mortar indicating people's awareness of the binding properties of calcite.

Risks and reliability of manufacturing processes as related to composite materials for spacecraft structures

NASA Technical Reports Server (NTRS)

Bao, Han P.

1995-01-01

Fabricating primary aircraft and spacecraft structures using advanced composite materials entail both benefits and risks. The benefits come from much improved strength-to-weight ratios and stiffness-to-weight ratios, potential for less part count, ability to tailor properties, chemical and solvent resistance, and superior thermal properties. On the other hand, the risks involved include high material costs, lack of processing experience, expensive labor, poor reproducibility, high toxicity for some composites, and a variety of space induced risks. The purpose of this project is to generate a manufacturing database for a selected number of materials with potential for space applications, and to rely on this database to develop quantitative approaches to screen candidate materials and processes for space applications on the basis of their manufacturing risks including costs. So far, the following materials have been included in the database: epoxies, polycyanates, bismalemides, PMR-15, polyphenylene sulfides, polyetherimides, polyetheretherketone, and aluminum lithium. The first four materials are thermoset composites; the next three are thermoplastic composites, and the last one is is a metal. The emphasis of this database is on factors affecting manufacturing such as cost of raw material, handling aspects which include working life and shelf life of resins, process temperature, chemical/solvent resistance, moisture resistance, damage tolerance, toxicity, outgassing, thermal cycling, and void content, nature or type of process, associate tooling, and in-process quality assurance. Based on industry experience and published literature, a relative ranking was established for each of the factors affecting manufacturing as listed above. Potential applications of this database include the determination of a delta cost factor for specific structures with a given process plan and a general methodology to screen materials and processes for incorporation into the current

Composite Material Hazard Assessment at Crash Sites

DTIC Science & Technology

2015-01-01

advanced composite materials. All personnel involved in rescue in close crash-site proximity are required to wear self -contained breathing apparatus...close crash-site proximity are required to wear self -contained breathing apparatus, chemical protective clothing, leather gloves, and neoprene...Take extra precaution when handling these materials. Nitrile rubber gloves can be worn underneath the leather gloves to provide chemical hazard

Fungal degradation of fiber-reinforced composite materials

NASA Technical Reports Server (NTRS)

Gu, J. D.; Lu, C.; Mitchell, R.; Thorp, K.; Crasto, A.

1997-01-01

As described in a previous report, a fungal consortium isolated from degraded polymeric materials was capable of growth on presterilized coupons of five composites, resulting in deep penetration into the interior of all materials within five weeks. Data describing the utilization of composite constituents as nutrients for the microflora are described in this article. Increased microbial growth was observed when composite extract was incubated with the fungal inoculum at ambient temperatures. Scanning electron microscopic observation of carbon fibers incubated with a naturally developed population of microorganisms showed the formation of bacterial biofilms on the fiber surfaces, suggesting possible utilization of the fiber chemical sizing as carbon and energy sources. Electrochemical impedance spectroscopy was used to monitor the phenomena occurring at the fiber-matrix interfaces. Significant differences were observed between inoculated and sterile panels of the composite materials. A progressive decline in impedance was detected in the inoculated panels. Several reaction steps may be involved in the degradation process. Initial ingress of water into the resin matrix appeared to be followed by degradation of fiber surfaces, and separation of fibers from the resin matrix. This investigation suggested that composite materials are susceptible to microbial attack by providing nutrients for growth.

Chemical Composition by the APXS along the Downhill Traverse of the Mars Exploration Rover Spirit at Gusev Crater

NASA Technical Reports Server (NTRS)

Bruckner, J.; Dreibus, G.; Gellert, R.; Clark, B.C.; Cohen, B.; McCoy, T.; Ming, D.W.; Mittlefehldt, D.W.; Yen, A.; Athena Science Team

2006-01-01

The Alpha Particle X-ray Spectrometer (APXS) onboard the Mars Exploration Rover Spirit continues to determine the elemental composition of samples at Gusev Crater. Starting around sol 600 the rover descended Husband Hill, which is part of the Columbia Hills, visited the inner basin with a large dune field, called 'El Dorado', and parked at Low Ridge to conserve energy during the martian winter. Many unique samples were discovered by the instruments onboard Spirit during her downhill traverse. Here, we report only on the chemical data obtained by the APXS. The compositions of some of the soil samples are comparable to the mean soil determined along the earlier traverse. However, a light-toned subsurface sample (disturbed by the rover wheels), called Dead Sea Samra , showed the highest sulfur content of all soil samples, the lowest Na, Mg, Al, Cl, K, Ca, Ti, Mn, and Zn, among the lowest Si and P, and among the highest Cr, Fe and Ni. Assuming ferric sulfate as a major mineral, large amounts of a pure silica phase must be present. Color and quantity of Dead Sea Samra resemble somewhat an earlier soil called Paso Robles , though the latter is a mixture of sulfates with phosphate-rich soil. Manganese in Dead Sea Samra is so low that the Fe/Mn ratio exceeds 300, a value that has never been found previously on Mars (Fe/Mn ratio of 46 for Gusev basalts), indicating that only Fe(3+) occurs. The dune field El Dorado contained granulated material that exhibited the highest Mg and Ni concentrations and the lowest S and Cl compared to all other soils implying an enrichment of olivine-rich sands. Two outcrops, called Algonquin and Comanche , revealed compositions that differ significantly from those of earlier outcrops as they have the highest concentrations of Mg, Fe, and Ni (except for Ni in Independence) and the lowest of Al, K (detection limit), Ca, and Ti of all brushed and almost all abraded rocks. Normative estimates assign them the highest olivine contents ever found for

Effects of Ni content on nanocrystalline Fe-Co-Ni ternary alloys synthesized by a chemical reduction method

NASA Astrophysics Data System (ADS)

Chokprasombat, Komkrich; Pinitsoontorn, Supree; Maensiri, Santi

2016-05-01

Magnetic properties of Fe-Co-Ni ternary alloys could be altered by changing of the particle size, elemental compositions, and crystalline structures. In this work, Fe50Co50-xNix nanoparticles (x=10, 20, 40, and 50) were prepared by the novel chemical reduction process. Hydrazine monohydrate was used as a reducing agent under the concentrated basic condition with the presence of poly(vinylpyrrolidone). We found that the nanoparticles were composed of Fe, Co and Ni with compositions according to the molar ratio of the metal sources. Interestingly, the particles were well-crystalline at the as-prepared state without post-annealing at high temperature. Increasing Ni content resulted in phase transformation from body centered cubic (bcc) to face centered cubic (fcc). For the fcc phase, the average particle size decreased when increased the Ni content; the Fe50Ni50 nanoparticles had the smallest average size with the narrowest size distribution. In additions, the particles exhibited ferromagnetic properties at room temperature with the coercivities higher than 300 Oe, and the saturation magnetiation decreased with increasing Ni content. These results suggest that the structural and magnetic properties of Fe-Co-Ni alloys could be adjusted by varying the Ni content.

Composite Materials for Hazard Mitigation of Reactive Metal Hydrides.

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

Pratt, Joseph William; Cordaro, Joseph Gabriel; Sartor, George B.

2012-02-01

In an attempt to mitigate the hazards associated with storing large quantities of reactive metal hydrides, polymer composite materials were synthesized and tested under simulated usage and accident conditions. The composites were made by polymerizing vinyl monomers using free-radical polymerization chemistry, in the presence of the metal hydride. Composites with vinyl-containing siloxane oligomers were also polymerized with and without added styrene and divinyl benzene. Hydrogen capacity measurements revealed that addition of the polymer to the metal hydride reduced the inherent hydrogen storage capacity of the material. The composites were found to be initially effective at reducing the amount of heatmore » released during oxidation. However, upon cycling the composites, the mitigating behavior was lost. While the polymer composites we investigated have mitigating potential and are physically robust, they undergo a chemical change upon cycling that makes them subsequently ineffective at mitigating heat release upon oxidation of the metal hydride. Acknowledgements The authors would like to thank the following people who participated in this project: Ned Stetson (U.S. Department of Energy) for sponsorship and support of the project. Ken Stewart (Sandia) for building the flow-through calorimeter and cycling test stations. Isidro Ruvalcaba, Jr. (Sandia) for qualitative experiments on the interaction of sodium alanate with water. Terry Johnson (Sandia) for sharing his expertise and knowledge of metal hydrides, and sodium alanate in particular. Marcina Moreno (Sandia) for programmatic assistance. John Khalil (United Technologies Research Corp) for insight into the hazards of reactive metal hydrides and real-world accident scenario experiments. Summary In an attempt to mitigate and/or manage hazards associated with storing bulk quantities of reactive metal hydrides, polymer composite materials (a mixture of a mitigating polymer and a metal hydride) were synthesized and

Method to fabricate layered material compositions

DOEpatents

Fleming, James G.; Lin, Shawn-Yu

2004-11-02

A new class of processes suited to the fabrication of layered material compositions is disclosed. Layered material compositions are typically three-dimensional structures which can be decomposed into a stack of structured layers. The best known examples are the photonic lattices. The present invention combines the characteristic features of photolithography and chemical-mechanical polishing to permit the direct and facile fabrication of, e.g., photonic lattices having photonic bandgaps in the 0.1-20.mu. spectral range.

Chemical composition of solar dried blood and the ruminal content and its effect on performance of Japanese quails

PubMed Central

Mishra, Jyotiprabha; Abraham, Robinson J. J; Rao, V. Appa; Rajini, R. Asha; Mishra, B. P.; Sarangi, N. R.

2015-01-01

Aim: The aim was to determine the chemical composition of solar dried blood and rumen content (DBRC) and further ascertain the concentration at which DBRC could be included in Japanese quail diets without any adverse effect on its performance. Materials and Methods: Feeding trial on the effect of DBRC on performance of Japanese quails was studied up to 5 weeks. 252 numbers of day old (Nandanam Type III breed) Japanese quails were purchased from Poultry Research Station, Madhavaram and divided into 7 batches (control+ six treatments) each consisting of 36 birds. The DBRC was included at 0%, 5%, 10%, 15%, 20%, 25% and 30% in diets as control, treatment-1 (T1), treatment-2 (T2), treatment-3 (T3), treatment-4 (T4), treatment-5 (T5) and treatment-6 (T6) respectively in a completely randomized design to replace soybean meal in Japanese quail feed. The birds were provided with ad-labidum feed and drinking water ad-libitum during the entire experimental period. Results: The crude protein (CP), crude fiber (CF), ether extract (EE) and ash contents of DBRC were 35.87%, 17.40%, 3.6% and 12.6%, respectively. The amount of essential amino acids and non-essential amino acid content were found to be 12.98 and 4.87 (g/100 g of feed) respectively in DBRC feed. Result showed that all birds fed DBRC diets performed better than the control group. Mortality was unaffected by dietary treatments. There was a significant difference (p<0.01) observed in weight gain in treatment groups compared to the control. Conclusion: Up to 30% DBRC could be incorporated in the diets of Japanese quails without any adverse effects on its performance. PMID:27047002

Chemical composition studies of flint with different origins

NASA Astrophysics Data System (ADS)

Zarina, Liga; Seglins, Valdis; Kostjukovs, Juris; Burlakovs, Juris

2015-04-01

Flint is a widely used material in the Stone Age because of its physical characteristics, which makes the material suitable for obtaining tools with sharp working edges. Chert, flint, chalcedony, agate and jasper in composition and several other physical characteristics are very similar. Therefore in archaeology most often they are determined simplified and are not distinguished, but described as flint or chert, denoting only the material in a general sense. However, in-depth studies it is necessary accurately identify the rock type and, in addition, to determine the origin of the flint and the conditions of the formation for the various archaeological research needs. As a typical example can be noted the localization problems in determining whether flint is local, or have emerged in the region through the exchange or by transportation. Flint consists mainly from quartz and mostly it has cryptocrystalline or amorphous structure. In nature it occurs as nodules and interbedded inclusions in sedimentary deposits as a result of digenesis processes when calcium carbonate is replaced with silicia. Bedded chert primarily is accumulations originated from excess alkalinity in the sediments. Flint can also be formed in the crystallization processes of the chemically unstable amorphous silicia. In this context, it should be noted that flint is naturally heterogeneous and very varied material by the physical properties and therefore problematic in many contemporary studies. In the study different origin flint samples from England, Denmark and Latvia were compared after their chemical composition. Flint nodules from Northern Europe chalk cliffs formed as inclusions in interbedded deposits or results of the digenesis and samples of chalcedony saturated dolomite from Latvia formed in hydrothermal processes were analysed using XRD and XRF methods. The obtained data were statistically analysed, identifying major, minor and trace elements and subsequently assessing the chemical

Elaboration of Alumina-Zirconia Composites: Role of the Zirconia Content on the Microstructure and Mechanical Properties

PubMed Central

Naglieri, Valentina; Palmero, Paola; Montanaro, Laura; Chevalier, Jérôme

2013-01-01

Alumina-zirconia (AZ) composites are attractive structural materials, which combine the high hardness and Young’s modulus of the alumina matrix with additional toughening effects, due to the zirconia dispersion. In this study, AZ composites containing different amounts of zirconia (in the range 5–20 vol %) were prepared by a wet chemical method, consisting on the surface coating of alumina powders by mixing them with zirconium salt aqueous solutions. After spray-drying, powders were calcined at 600 °C for 1 h. Green bodies were then prepared by two methods: uniaxial pressing of spray-dried granules and slip casting of slurries, obtained by re-dispersing the spray dried granulates. After pressureless sintering at 1500 °C for 1 h, the slip cast samples gave rise to fully dense materials, characterized by a quite homogeneous distribution of ZrO2 grains in the alumina matrix. The microstructure, phase composition, tetragonal to monoclinic transformation behavior and mechanical properties were investigated and are here discussed as a function of the ZrO2 content. The material containing 10 vol % ZrO2 presented a relevant hardness and exhibited the maximum value of KI0, mainly imputable to the t → m transformation at the crack tip. PMID:28809262

Use of near infrared spectroscopy for estimating meat chemical composition, quality traits and fatty acid content from cattle fed sunflower or flaxseed.

PubMed

Prieto, N; López-Campos, O; Aalhus, J L; Dugan, M E R; Juárez, M; Uttaro, B

2014-10-01

This study tested the ability of near infrared reflectance spectroscopy (NIRS) to predict meat chemical composition, quality traits and fatty acid (FA) composition from 63 steers fed sunflower or flaxseed in combination with high forage diets. NIRS calibrations, tested by cross-validation, were successful for predicting crude protein, moisture and fat content with coefficients of determination (R(2)) (RMSECV, g·100g(-1) wet matter) of 0.85 (0.48), 0.90 (0.60) and 0.86 (1.08), respectively, but were not reliable for meat quality attributes. This technology accurately predicted saturated, monounsaturated and branched FA and conjugated linoleic acid content (R(2): 0.83-0.97; RMSECV: 0.04-1.15mg·g(-1) tissue) and might be suitable for screening purposes in meat based on the content of FAs beneficial to human health such as rumenic and vaccenic acids. Further research applying NIRS to estimate meat quality attributes will require the use on-line of a fibre-optic probe on intact samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

Controlling the Sn-C bonds content in SnO2@CNTs composite to form in situ pulverized structure for enhanced electrochemical kinetics.

PubMed

Cheng, Yayi; Huang, Jianfeng; Qi, Hui; Cao, Liyun; Luo, Xiaomin; Li, Jiayin; Xu, Zhanwei; Yang, Jun

2017-12-07

The Sn-C bonding content between the SnO 2 and CNTs interface was controlled by the hydrothermal method and subsequent heat treatment. Electrochemical analysis found that the SnO 2 @CNTs with high Sn-C bonding content exhibited much higher capacity contribution from alloying and conversion reaction compared with the low content of Sn-C bonding even after 200 cycles. The high Sn-C bonding content enabled the SnO 2 nanoparticles to stabilize on the CNTs surface, realizing an in situ pulverization process of SnO 2 . The in situ pulverized structure was beneficial to maintain the close electrochemical contact of the working electrode during the long-term cycling and provide ultrafast transfer paths for lithium ions and electrons, which promoted the alloying and conversion reaction kinetics greatly. Therefore, the SnO 2 @CNTs composite with high Sn-C bonding content displayed highly reversible alloying and conversion reaction. It is believed that the composite could be used as a reference for design chemically bonded metal oxide/carbon composite anode materials in lithium-ion batteries.

Composite Materials: An Educational Need.

ERIC Educational Resources Information Center

Saliba, Tony E.; Snide, James A.

1990-01-01

Described is the need to incorporate the concepts and applications of advanced composite materials into existing chemical engineering programs. Discussed are the justification for, and implementation of topics including transport phenomena, kinetics and reactor design, unit operations, and product and process design. (CW)

Physico-chemical characterisation of material fractions in household waste: Overview of data in literature.

PubMed

Götze, Ramona; Boldrin, Alessio; Scheutz, Charlotte; Astrup, Thomas Fruergaard

2016-03-01

State-of-the-art environmental assessment of waste management systems rely on data for the physico-chemical composition of individual material fractions comprising the waste in question. To derive the necessary inventory data for different scopes and systems, literature data from different sources and backgrounds are consulted and combined. This study provides an overview of physico-chemical waste characterisation data for individual waste material fractions available in literature and thereby aims to support the selection of data fitting to a specific scope and the selection of uncertainty ranges related to the data selection from literature. Overall, 97 publications were reviewed with respect to employed characterisation method, regional origin of the waste, number of investigated parameters and material fractions and other qualitative aspects. Descriptive statistical analysis of the reported physico-chemical waste composition data was performed to derive value ranges and data distributions for element concentrations (e.g. Cd content) and physical parameters (e.g. heating value). Based on 11,886 individual data entries, median values and percentiles for 47 parameters in 11 individual waste fractions are presented. Exceptional values and publications are identified and discussed. Detailed datasets are attached to this study, allowing further analysis and new applications of the data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential characteristics in the chemical composition of bananas from Tenerife (Canary Islands) and Ecuador.

PubMed

Forster, Markus Paul; Rodríguez Rodríguez, Elena; Díaz Romero, Carlos

2002-12-18

The contents of moisture, protein, ash, ascorbic acid, glucose, fructose, total sugars, and total and insoluble fiber were determined in cultivars of bananas (Gran Enana and Pequeña Enana) harvested in Tenerife and in bananas (Gran Enana) from Ecuador. The chemical compositions in the bananas from Tenerife and from Ecuador were clearly different. The cultivar did not influence the chemical composition, except for insoluble fiber content. Variations of the chemical composition were observed in the bananas from Tenerife according to cultivation method (greenhouse and outdoors), farming style (conventional and organic), and region of production (north and south). A highly significant (r = 0.995) correlation between glucose and fructose was observed. Correlations of ash and protein contents tend to separate the banana samples according to origin. A higher content of protein, ash, and ascorbic acid was observed as the length of the banana decreased. Applying factor analysis, the bananas from Ecuador were well separated from the bananas produced in Tenerife. An almost total differentiation (91.7%) between bananas from Tenerife and bananas from Ecuador was obtained by selecting protein, ash, and ascorbic acid content and applying stepwise discriminant analysis. By selecting the bananas Pequeña Enana and using discriminant analysis, a clear separation of the samples according to the region of production and farming style was observed.

Dissolved organic matter composition of Arctic rivers: Linking permafrost and parent material to riverine carbon

USGS Publications Warehouse

O’Donnell, Jonathan A.; Aiken, George R.; Swanson, David K.; Santosh, Panda; Butler, Kenna D.; Baltensperger, Andrew P.

2016-01-01

Recent climate change in the Arctic is driving permafrost thaw, which has important implications for regional hydrology and global carbon dynamics. Permafrost is an important control on groundwater dynamics and the amount and chemical composition of dissolved organic matter (DOM) transported by high-latitude rivers. The consequences of permafrost thaw for riverine DOM dynamics will likely vary across space and time, due in part to spatial variation in ecosystem properties in Arctic watersheds. Here we examined watershed controls on DOM composition in 69 streams and rivers draining heterogeneous landscapes across a broad region of Arctic Alaska. We characterized DOM using bulk dissolved organic carbon (DOC) concentration, optical properties, and chemical fractionation and classified watersheds based on permafrost characteristics (mapping of parent material and ground ice content, modeling of thermal state) and ecotypes. Parent material and ground ice content significantly affected the amount and composition of DOM. DOC concentrations were higher in watersheds underlain by fine-grained loess compared to watersheds underlain by coarse-grained sand or shallow bedrock. DOC concentration was also higher in rivers draining ice-rich landscapes compared to rivers draining ice-poor landscapes. Similarly, specific ultraviolet absorbance (SUVA254, an index of DOM aromaticity) values were highest in watersheds underlain by fine-grained deposits or ice-rich permafrost. We also observed differences in hydrophobic organic acids, hydrophilic compounds, and DOM fluorescence across watersheds. Both DOC concentration and SUVA254 were negatively correlated with watershed active layer thickness, as determined by high-resolution permafrost modeling. Together, these findings highlight how spatial variations in permafrost physical and thermal properties can influence riverine DOM.

Laboratory analogues simulating Titan's atmospheric aerosols: Compared chemical compositions of grains and thin films

NASA Astrophysics Data System (ADS)

Carrasco, Nathalie; Jomard, François; Vigneron, Jackie; Etcheberry, Arnaud; Cernogora, Guy

2016-09-01

Two sorts of solid organic samples can be produced in laboratory experiments simulating Titan's atmospheric reactivity: grains in the volume and thin films on the reactor walls. We expect that grains are more representative of Titan's atmospheric aerosols, but films are used to provide optical indices for radiative models of Titan's atmosphere. The aim of the present study is to address if these two sorts of analogues are chemically equivalent or not, when produced in the same N2-CH4 plasma discharge. The chemical compositions of both these materials are measured by using elemental analysis, XPS analysis and Secondary Ion Mass Spectrometry. The main parameter probed is the CH4/N2 ratio to explore various possible chemical regimes. We find that films are homogeneous but significantly less rich in nitrogen and hydrogen than grains produced in the same experimental conditions. This surprising difference in their chemical compositions could be explained by the efficient etching occurring on the films, which stay in the discharge during the whole plasma duration, whereas the grains are ejected after a few minutes. The higher nitrogen content in the grains possibly involves a higher optical absorption than the one measured on the films, with a possible impact on Titan's radiative models.

Cometary coma chemical composition (C4) mission. [Abstract only

NASA Technical Reports Server (NTRS)

Carle, G. C.; Clark, B. C.; Niemann, H. B.; Alexander, M.; Knocke, P. C.; O'Hara, B. J.

1994-01-01

Cometary missions are of enormous fundamental importance for many different space science disciplines, including exobiology. Comets are presumed relics of the earliest, most primitive material in the solar nebula and are related to the planetesimals. They undoubtedly provided a general enrichment of volatiles to the inner solar system (contributing to atmospheres and oceans) and may have been key to the origin of life. A Discovery class, comet rendezvous mission, the Cometary Coma Chemical Composition (C4) Mission, was selected for further study by NASA earlier this year. The C4 Mission is a highly focused and usefully-limited subset of the Cometary Rendezvous Asteroid Flyby (CRAF) Mission, concentrating exclusively on measurements which will lead to an understanding of the chemical composition and make-up of the cometary nucleus. The scientific goals of the Cometary Coma Chemical Composition (C4) Mission are to rendezvous with a short-period comet and (1) to determine the elemental, chemical, and isotopic composition of the nucleus and (2) to characterize the chemical and isotopic nature of its atmosphere. Further, it is a goal to obtain preliminary data on the development of the coma (dust and gas composition) as a function of time and orbital position.

[Analysis and utilization value discussion of multiple chemical composition in different tissues of Abelmoschus manihot].

PubMed

Liu, Jie; Guo, Sheng; Duan, Jin-Ao; Yan, Hui; Qian, Da-Wei; Tang, Hai-Tao; Tang, Ren-Mao

2016-10-01

This research is to analyze the resourceful chemical composition in different tissues (root, stem, leaf and flower) of Abelmoschus manihot and evaluate their utilizing value. The flavonoids, soluble polysaccharides, cellulose, nucleosides and amino acids in the different tissues of A. manihot were determined by HPLC coupled with UV-Vis spectrophotpmetry, and UPLC-TQ/MS. The flowers are rich in the resourceful chemical compositions of flavonoids which mainly consist of hyperoside, isoquercitrin, cotton-8-O-glucuronide, myricetin, quercetin-3'-O-glucoside, rutin and quercetin. The total content of these flavonoids is 25.450 mg•g-1 in the flowers, while they are trace in the other tissues.Different tissues of A. manihot are rich in soluble polysaccharides and celluloses and the stems have the highest content(19.76%) of soluble polysaccharides, while the roots have the highest content (29.88%) of cellulose. Total of 21 amino acids and 9 nucleosides were detected in this plant, and the flowers have the highest content of amino acids(4.737 mg•g⁻¹), while the leaves have the highest content of nucleosides (1.474 mg•g⁻¹). A. manihot is rich in the resourceful chemical compositions, and its constituents and contents are various in different tissues of this plant.The results provided a scientific basis for the utilization and industrial development of A. manihot plants. Copyright© by the Chinese Pharmaceutical Association.

Analysis of waste coal from the enterprises of Kemerovo region as raw materials for production of ceramic materials

NASA Astrophysics Data System (ADS)

Stolboushkin, A. Yu; Akst, D. V.; Fomina, O. A.; Ivanov, A. I.; Syromyasov, V. A.

2017-09-01

The analysis of waste coal from mining enterprises of Kemerovo region as raw materials for production of building ceramics is given. The results of studies of material, chemical and mineralogical compositions of waste coal from Abashevskaya processing plant (Novokuznetsk) are presented. It was established that the chemical composition of waste coal refers to aluminosilicate raw materials with a high content of alumina and coloring oxides, the residual carbon content in the wastes is 12-25 %. According to the granulometric composition the waste coal is basically a sandy-dusty fraction with a small amount of clay particles (1-3 %). Additional grinding of coal waste and the introduction of a clay additive in an amount of up to 30 % are recommended. The results of the study of the mineral composition of waste coal are presented. Clay minerals are represented in the descending order by hydromuscovite, montmorillonite and kaolinite, minerals-impurities consist of quartz, feldspar fine-dispersed carbonates. The results of the investigation of ceramic-technological properties of waste coal, which belong to the group of moderately plastic low-melting raw materials, are given. As a result of a comprehensive study it was been established that with chemical, granulometric and mineralogical compositions waste coal with the reduced residual carbon can be used in the production of ceramic bricks.

An Investigation of Fiber Reinforced Chemically Bonded Phosphate Ceramic Composites at Room Temperature.

PubMed

Ding, Zhu; Li, Yu-Yu; Lu, Can; Liu, Jian

2018-05-21

In this study, chemically bonded phosphate ceramic (CBPC) fiber reinforced composites were made at indoor temperatures. The mechanical properties and microstructure of the CBPC composites were studied. The CBPC matrix of aluminum phosphate binder, metakaolin, and magnesia with different Si/P ratios was prepared. The results show that when the Si/P ratio was 1.2, and magnesia content in the CBPC was 15%, CBPC reached its maximum flexural strength. The fiber reinforced CBPC composites were prepared by mixing short polyvinyl alcohol (PVA) fibers or unidirectional continuous carbon fiber sheets. Flexural strength and dynamic mechanical properties of the composites were determined, and the microstructures of specimens were analyzed by scanning electron micrography, X-ray diffraction, and micro X-ray computed tomography. The flexural performance of continuous carbon fiber reinforced CBPC composites was better than that of PVA fiber composites. The elastic modulus, loss modulus, and loss factor of the fiber composites were measured through dynamic mechanical analysis. The results showed that fiber reinforced CBPC composites are an inorganic polymer viscoelastic material with excellent damping properties. The reaction of magnesia and phosphate in the matrix of CBPC formed a different mineral, newberyite, which was beneficial to the development of the CBPC.

Chemical composition and morphology of welding fume particles and grinding dusts.

PubMed

Karlsen, J T; Farrants, G; Torgrimsen, T; Reith, A

1992-05-01

Elemental composition and morphology of pure manual metal arc (MMA) welding fumes, pure grinding dust, and combined fume/dust air samples were collected and determined separately under semilaboratory conditions. The base material was stainless steel. The purpose of the present study was to create a "synthetic" work situation under semilaboratory conditions by combining one grinding period and two MMA welding periods and comparing these results with results during welding in a workshop. The duty cycles of pure welding and of pure grinding were also observed. A comparison was also made between metal inert gas (MIG) and MMA welding on stainless steel as well as a nickel-rich alloy under regular conditions. The amount of collected material was determined by weighing the membrane filters before and after exposure, and the element contents were determined by atomic spectroscopy. Other transmission electron microscopy (TEM) filters were used for TEM and computer-image analysis, in which the amount of collected material and its morphological characteristics were observed. The arcing time and the consumption of filler material were estimated for different kinds of electrodes. Chemical analysis showed that the contents of manganese and total chromium were lower in grinding dust than in welding fumes. The contents of hexavalent chromium, Cr(VI), in grinding dust were undetectable. Samples collected in welding shops where concomitant grinding was performed contained about 30% less Cr(VI) than those collected under laboratory conditions during welding only. The sizes and shapes of the particles depend on the welding process and distance of collection from the plume of the fume. To compare laboratory experiments with regular welding situations, the experiment must resemble industrial welding.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluating the effect of some mechanical properties for chemically treated various natural fibers reinforced polyester composite

NASA Astrophysics Data System (ADS)

Salih, Wafaa Mahdi; Abdulkader, Niveen Jamal; Salih, Sana Mahdi

2018-05-01

This research were studied the effect of some mechanical properties for composite materials reinforced fiber and prepared from material (polyester with various natural fibers) then studied the effect of chemical treatment on the same fiber immerse in 10% NaOH solution for half an hour and then compared, the results of the same test of composite materials without and with chemical treatment and the results proved that there is a clear effect when treat the fiber compared to non-chemical treatment of the fibers also noted that hemp fibers loaded the stress higher than other fibers for both cases to distinguish them that the hemp fiber has continuous fibers either the other fibers are characterized by the type of cross linking or chopped types in tensile test, and the results of the same test of composite materials without and with chemical treatment and the results proved that the hardness of the fiber composite while the treated fiber composite samples better than the untreated fiber, and from the figures the palm leaf has the highest value than lufa fiber, hemp fiber and the smallest value is in sisal fiber because of the nature of formation fibers materials.

Relationship of Water Content With Silicon and Fluorine Contents of Silicone-Hydrogel Contact Lens Materials.

PubMed

Dupre, Terin E; Benjamin, William J

2018-06-25

The relationship between water (W) content and silicon (Si) content of silicone-hydrogel (SiHy) contact lens materials was inspected using identical methodologies, equipment, and operators for materials composing 16 types of commercially available SiHy contact lenses. Fluorine (F) content was included in the analysis for the three materials also containing a fluoropolymer. One type of lens consisted of a bulk SiHy material coated with thin layers of conventional hydrogel. SiHy materials were obtained in the form of 16 contact lens brands purchased on the open market in a common range of refractive powers from -3 to +6 D in single lots. All test lenses were equilibrated at room temperature in a standard saline recommended in the American National Standards Institute Z80.20-2016 and International Organization for Standardization (ISO) 18369-4:2017 standards. W content was obtained gravimetrically, in %, according to those standards for 16 lenses of each SiHy material. Si content was determined in % using inductively coupled plasma optical emission spectroscopy for four digested lenses of each material. F content was determined in % using an ion-selective electrode for four combusted lenses of each of the three fluorinated SiHy materials. W and Si contents of the bulk SiHy material of the coated lens were estimated by computational exclusion of the hydrogel layers. The linear coefficients of determination (R, n=16) were -0.7576 (relating mean dry Si content [n=4] to mean W content [n=16]) and -0.8819 (relating mean hydrated Si content [n=4] to mean W content [n=16]). When the 4 SiHy materials that were fluorinated or coated were excluded from the analysis, the R values (n=12) were -0.8869 and -0.9263, respectively. When F contents and the coating were added to the assessments, the linear coefficients of determination (R, n=16) became -0.8948 (relating mean dry [Si+F] content to mean W content) and -0.9397 (relating mean hydrated [Si+F] content to mean W content

Chemical compositions, infrared spectroscopy, and X-ray diffractometry study on brown-rotted woods

Treesearch

Gai-Yun Li; Luo-Hua Huang; Chung Hse; Te-Fu Qin

2011-01-01

The effect of brown-rot decay on the chemical composition and crystallinity of Masson pine was studied by exposing it to Wolfiporia cocos (Schwein.) Ryvarden and Gilbn. for durations of up to 15 weeks in the field. The holocellulose content, α-cellulose content, and wood crystallinity decreased slowly in the initial stage, followed by a significant reduction...

New Coll-HA/BT composite materials for hard tissue engineering.

PubMed

Zanfir, Andrei Vlad; Voicu, Georgeta; Busuioc, Cristina; Jinga, Sorin Ion; Albu, Madalina Georgiana; Iordache, Florin

2016-05-01

The integration of ceramic powders in composite materials for bone scaffolds can improve the osseointegration process. This work was aimed to the synthesis and characterization of new collagen-hydroxyapatite/barium titanate (Coll-HA/BT) composite materials starting from barium titanate (BT) nanopowder, hydroxyapatite (HA) nanopowder and collagen (Coll) gel. BT nanopowder was produced by combining two wet-chemical approaches, sol-gel and hydrothermal methods. The resulting materials were characterized in terms of phase composition and microstructure by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. Moreover, the biocompatibility and bioactivity of the composite materials were assessed by in vitro tests. The synthesized BT particles exhibit an average size of around 35 nm and a spherical morphology, with a pseudo-cubic or tetragonal symmetry. The diffraction spectra of Coll-HA and Coll-HA/BT composite materials indicate a pronounced interaction between Col and the mineral phases, meaning a good mineralization of Col fibres. As well, the in vitro tests highlight excellent osteoinductive properties for all biological samples, especially for Coll-HA/BT composite materials, fact that can be attributed to the ferromagnetic properties of BT. Copyright © 2016 Elsevier B.V. All rights reserved.

Health, safety and environmental requirements for composite materials

NASA Technical Reports Server (NTRS)

Hazer, Kathleen A.

1994-01-01

The health, safety and environmental requirements for the production of composite materials are discussed. The areas covered include: (1) chemical identification for each chemical; (2) toxicology; (3) industrial hygiene; (4) fire and safety; (5) environmental aspects; and (6) medical concerns.

Stratospheric experiments on curing of composite materials

NASA Astrophysics Data System (ADS)

Chudinov, Viacheslav; Kondyurin, Alexey; Svistkov, Alexander L.; Efremov, Denis; Demin, Anton; Terpugov, Viktor; Rusakov, Sergey

2016-07-01

Future space exploration requires a large light-weight structure for habitats, greenhouses, space bases, space factories and other constructions. A new approach enabling large-size constructions in space relies on the use of the technology of polymerization of fiber-filled composites with a curable polymer matrix applied in the free space environment on Erath orbit. In orbit, the material is exposed to high vacuum, dramatic temperature changes, plasma of free space due to cosmic rays, sun irradiation and atomic oxygen (in low Earth orbit), micrometeorite fluence, electric charging and microgravitation. The development of appropriate polymer matrix composites requires an understanding of the chemical processes of polymer matrix curing under the specific free space conditions to be encountered. The goal of the stratospheric flight experiment is an investigation of the effect of the stratospheric conditions on the uncured polymer matrix of the composite material. The unique combination of low residual pressure, high intensity UV radiation including short-wave UV component, cosmic rays and other aspects associated with solar irradiation strongly influences the chemical processes in polymeric materials. We have done the stratospheric flight experiments with uncured composites (prepreg). A balloon with payload equipped with heater, temperature/pressure/irradiation sensors, microprocessor, carrying the samples of uncured prepreg has been launched to stratosphere of 25-30 km altitude. After the flight, the samples have been tested with FTIR, gel-fraction, tensile test and DMA. The effect of cosmic radiation has been observed. The composite was successfully cured during the stratospheric flight. The study was supported by RFBR grants 12-08-00970 and 14-08-96011.

Preparation, chemical composition and storage studies of quamachil (Pithecellobium dulce L.) aril powder.

PubMed

Rao, Galla Narsing; Nagender, Allani; Satyanarayana, Akula; Rao, Dubasi Govardhana

2011-02-01

Quamachil aril powder samples were prepared and evaluated for chemical composition and sensory quality by packing in two packaging systems during storage for six months. The protein contents were 12.4 and 15.0% in white and pink aril powders respectively. The titrable acidity of white and pink aril powders were 2.4 and 4.8% respectively. Ca and Fe contents in white aril powder samples were 60 and 12 mg/100 g where as in pink aril powder 62 and 16 mg/100 g, respectively. The anthocyanin content in pink powder decreased from 50.5 to 11.2 and 14.1 mg/100 g in samples packed in polyethylene (PE) and metalised polyester polyethylene laminated pouches respectively. Total polyphenol amount increased in both the powders irrespective of packaging material. Sorption isotherms indicated that both white and pink aril powders were hygroscopic and equilibrated at low relative humidity of 28 and 32%, respectively.

Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites

PubMed Central

Gagani, Abedin I.; Echtermeyer, Andreas T.

2018-01-01

Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR) spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR) spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer–Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described. PMID:29641451

Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites.

PubMed

Krauklis, Andrey E; Gagani, Abedin I; Echtermeyer, Andreas T

2018-04-11

Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR) spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR) spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer-Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

System compliance dictates the effect of composite filler content on polymerization shrinkage stress.

PubMed

Wang, Zhengzhi; Chiang, Martin Y M

2016-04-01

The effect of filler content in dental restorative composites on the polymerization shrinkage stress (PS) is not straightforward and has caused much debate in the literature. Our objective in this study was to clarify the PS/filler content relationship based on analytical and experimental approaches, so that guidelines for materials comparison in terms of PS and clinical selection of dental composites with various filler content can be provided. Analytically, a simplified model based on linear elasticity was utilized to predict PS as a function of filler content under various compliances of the testing system, a cantilever beam-based instrument used in this study. The predictions were validated by measuring PS of composites synthesized using 50/50 mixtures of two common dimethacrylate resins with a variety of filler contents. Both experiments and predictions indicated that the influence of filler content on the PS highly depended on the compliance of the testing system. Within the clinic-relevant range of compliances and for the specific sample configuration tested, the PS increased with increasing filler content at low compliance of instrument, while increasing the compliance caused the effect of filler content on the PS to gradually diminish. Eventually, at high compliance, the PS inverted and decreased with increasing filler content. This compliance-dependent effect of filler content on PS suggests: (1) for materials comparison in terms of PS, the specific compliance at which the comparison being done should always be reported and (2) clinically, composites with relatively lower filler content could be selected for such cavities with relatively lower compliance (e.g. a Class-I cavity with thick tooth walls or the basal part in a cavity) and vice versa in order to reduce the final PS. Published by Elsevier Ltd.

Chemical Composition and Antioxidant, Anti-Inflammatory, and Antiproliferative Activities of Lebanese Ephedra Campylopoda Plant

PubMed Central

Kallassy, Hany; Fayyad-Kazan, Mohammad; Makki, Rawan; EL-Makhour, Yolla; Rammal, Hasan; Leger, David Y.; Sol, Vincent; Fayyad-Kazan, Hussein; Liagre, Bertrand; Badran, Bassam

2017-01-01

Background This study aimed to identify the phytochemical content and evaluate the antioxidant, anti-inflammatory, and antiproliferative capacities of various solvent extracts of Ephedra campylopoda stems. Material/Methods Fresh stems were suspended in 3 different solvent systems, including distilled water, ethanol, and methanol. The chemical composition was determined using high-performance liquid chromatography (HPLC), and the content of essential oil of this plant species was determined by gas chromatography (GC) coupled with mass spectrometry (MS). Antioxidant activity was determined using DPPH radical scavenging and Fe2+-chelating activity assays. Anti-inflammatory capacity was estimated by both evaluating RAW 264.7 murine macrophage cells-mediated secretion of PGE2 using ELISA technique, and quantifying the mRNA level of the pro-inflammatory cytokines (IL-α, IL-β and IL-6), chemokines (CCL3 and CCL4), and inflammation-inducible COX-2 and iNOS enzymes using quantitative real-time PCR (qRT-PCR). The antiproliferative potential was determined using the XTT viability assay. Results Our results showed that the alcoholic extracts were better than the aqueous one in terms of their chemical composition. In parallel, the alcoholic extracts showed more potent antioxidant, anti-inflammatory, and antiproliferative capacities than aqueous extract. Conclusions Our observations suggest that Ephedra campylopoda plant could be a promising resource of natural products with antioxidant, anti-inflammatory and antiproliferative capacities. PMID:28947729

Chemical composition and some trace element contents in coals and coal ash from Tamnava-Zapadno Polje Coal Field, Serbia

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

Vukasinovic-Pesic, V.; Rajakovic, L.J.

2009-07-01

The chemical compositions and trace element contents (Zn, Cu, Co, Cr, Ni, Pb, Cd, As, B, Hg, Sr, Se, Be, Ba, Mn, Th, V, U) in coal and coal ash samples from Tamnava-Zapadno Polje coal field in Serbia were studied. The coal from this field belongs to lignite. This high volatility coal has high moisture and low S contents, moderate ash yield, and high calorific value. The coal ash is abundant in alumosilicates. Many trace elements such as Ni > Cd > Cr > B > As > Cu > Co > Pb > V > Zn > Mn inmore » the coal and Ni > Cr > As > B > Cu > Co = Pb > V > Zn > Mn in the coal ash are enriched in comparison with Clarke concentrations.« less

The energetics of adhesion in composite materials

NASA Astrophysics Data System (ADS)

Harding, Philip Hiram

Composite materials are used throughout modern society, and often the most important parameter in determining their properties is the adhesion at material interfaces within the composite. A broad investigation is completed, the global objective of which is to develop understanding of the role of adhesion in composite materials. The scope of this study ranges from macroscopic effects of adhesion on filled polymer composites to microscopic adhesion measurements with engineered interfaces. The surface of a filler material is systematically modified and surface characterization techniques are used to quantify the influence of the surface treatments on surface energetics and wetting properties. Filled polymer composites are prepared and composite mechanical properties determined with beam deflection tests. Filler surface treatments significantly alter the composite yield stress for composites which fail interfacially and are observed to increase or decrease mechanical strength, depending on the chemical nature of the modification. Thermodynamic adhesion mechanisms active at the filler-matrix interfaces are then explored by making direct interfacial strength measurements whereby a single spherical particle is introduced into the polymeric matrix. Interfacial strength is determined by submitting the single-particle composite (SPC) to uni-axial tension and relating the macroscopic stress at interfacial failure to that experienced at the interface. The technique provides a measurement of interfacial strength between two elastic materials, one unaffected by frictional forces, viscoelasticity, and thermal stresses. The SPC measurements are used to verify proposed adhesion mechanisms at the various filler-polymer interfaces and establish the role of adhesion in the filled polymer composites. The SPC technique is then used to investigate the adhesion promotion mechanism of organofunctional silanes, which are shown to be controlled by the compatibility and penetration of the

Chemical composition, water vapor permeability, and mechanical properties of yuba film influenced by soymilk depth and concentration.

PubMed

Zhang, Siran; Lee, Jaesang; Kim, Yookyung

2018-03-01

Yuba is a soy protein-lipid film formed during heating of soymilk. This study described yuba as an edible film by analyzing its chemical composition, water vapor permeability (WVP), and mechanical properties. Three yuba films were prepared by using different concentrations and depths of soymilk: HS (86 g kg -1 and 2.3 cm), LS (70 g kg -1 and 2.3 cm), and LD (70 g kg -1 and 3.0 cm). As yuba was successively skimmed, the protein, lipid, and SH content decreased, but carbohydrate and SS content increased. Though both the initial concentration and the depth of soymilk affect the properties of the films, the depth of soymilk influences WVP and tensile strength (TS) more. The WVP of the HS and LS changed the least (13-17 g mm kPa -1 m -2 day 1 ), while that of the LD changed the most (13-35 g mm kPa -1 m -2 day -1 ). There were no differences (P > 0.05) in the TS between the HS and LS. LD had the greatest decrease of TS and the lowest TS among the groups. The earlier the yuba films were collected, the greater the elongation of the films was: 129% (HS), 113% (LS), and 155% (LD). The initial concentration and the depth of soymilk changed the chemical composition and structure of the yuba films. The LS yuba produced more uniform edible films with good mechanical properties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Chemical composition, fatty acid content and antioxidant potential of meat from goats supplemented with Moringa (Moringa oleifera) leaves, sunflower cake and grass hay.

PubMed

Qwele, K; Hugo, A; Oyedemi, S O; Moyo, B; Masika, P J; Muchenje, V

2013-03-01

The present study determined the chemical composition, fatty acid (FA) content and antioxidant capacity of meat from goats supplemented with Moringa oleifera leaves (MOL) or sunflower cake (SC) or grass hay (GH). The meat from goat supplemented with MOL had higher concentrations of total phenolic content (10.62±0.27 mg tannic acid equivalent E/g). The MOL significantly scavenged 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) radical to 93.51±0.19% (93.51±0.19%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical to 58.95±0.3% than other supplements. The antioxidative effect of MOL supplemented meat on catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD) and lipid oxidation (LO) was significantly (P<0.05) higher than other meat from goat feed on grass hay or those supplemented with sunflower seed cake. The present study indicated that the anti-oxidative potential of MOL may play a role in improving meat quality (chemical composition, colour and lipid stability). Copyright © 2012 Elsevier Ltd. All rights reserved.

An Overview of Recent Development in Composite Catalysts from Porous Materials for Various Reactions and Processes

PubMed Central

Xie, Zaiku; Liu, Zhicheng; Wang, Yangdong; Yang, Qihua; Xu, Longya; Ding, Weiping

2010-01-01

Catalysts are important to the chemical industry and environmental remediation due to their effective conversion of one chemical into another. Among them, composite catalysts have attracted continuous attention during the past decades. Nowadays, composite catalysts are being used more and more to meet the practical catalytic performance requirements in the chemical industry of high activity, high selectivity and good stability. In this paper, we reviewed our recent work on development of composite catalysts, mainly focusing on the composite catalysts obtained from porous materials such as zeolites, mesoporous materials, carbon nanotubes (CNT), etc. Six types of porous composite catalysts are discussed, including amorphous oxide modified zeolite composite catalysts, zeolite composites prepared by co-crystallization or overgrowth, hierarchical porous catalysts, host-guest porous composites, inorganic and organic mesoporous composite catalysts, and polymer/CNT composite catalysts. PMID:20559508

Development of Composite PCMs by Incorporation of Paraffin into Various Building Materials

PubMed Central

Memon, Shazim Ali; Liao, Wenyu; Yang, Shuqing; Cui, Hongzhi; Shah, Syed Farasat Ali

2015-01-01

In this research, we focused on the development of composite phase-change materials (CPCMs) by incorporation of a paraffin through vacuum impregnation in widely used building materials (Kaolin and ground granulated blast-furnace slag (GGBS)). The composite PCMs were characterized using environmental scanning electron microscopy (ESEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Moreover, thermal performance of cement paste composite PCM panels was evaluated using a self-designed heating system. Test results showed that the maximum percentage of paraffin retained by Kaolin and GGBS was found to be 18% and 9%, respectively. FT-IR results show that CPCMs are chemically compatible. The phase-change temperatures of CPCMs were in the human comfort zone, and they possessed considerable latent-heat storage capacity. TGA results showed that CPCMs are thermally stable, and they did not show any sign of degradation below 150 °C. From thermal cycling tests, it was revealed that the CPCMs are thermally reliable. Thermal performance tests showed that in comparison to the control room model, the room models prepared with CPCMs reduced both the temperature fluctuations and maximum indoor center temperature. Therefore, the prepared CPCMs have some potential in reducing peak loads in buildings when applied to building facade. PMID:28787953

New Approach to Synthesis of Powder and Composite Materials by Electron Beam. Part 1. Technological Features of the Process

NASA Astrophysics Data System (ADS)

Rudskoy, A. I.; Kondrat'ev, S. Yu.; Sokolov, Yu. A.

2016-05-01

Possibilities of electron beam synthesis of structural and tool composite materials are considered. It is shown that a novel process involving mathematical modeling of each individual operation makes it possible to create materials with programmable structure and predictable properties from granules of various specified chemical compositions and sizes.

[Biomimetic nanohydroxyapatite/gelatin composite material preparation and in vitro study].

PubMed

Li, Siriguleng; Hu, Xiaowen

2014-09-01

To prepare nHA/gelatin porous scaffold and to evaluate its physical and chemical properties and biocompatibility. We used nano-powders of HA and gelatin to prepare 3D porous composite scaffold by freeze-drying technique, and used scanning electron microscope, fourier transform infrared spectroscopy and universal testing machine to characterize the composite material. Osteoblasts were primarily cultured, and the third-passage osteoblasts were co-cultured with the composite material. The cell adhesion and morphology were examined under scanning electron microscope. The cell viability analysis was performed by MTT assay, and the alkaline phosphatase activity was measured with alkaline phosphatase kit. Scanning electron microscope showed that the scaffold possessed a 3-dimensional interconnected homogenous porous structure with pore sizes ranging from 150 to 400 μm. Fourier transform infrared spectroscopy showed that the composite material had a strong chemical bond between the inorganic phase and organic phase. The scaffold presented the compressive strength of (3.28 ± 0.51) MPa and porosities of (80.6 ± 4.1)%. Composite materials showed features of had good biocompatibility. Mouse osteoblasts were well adhered and spread on the materials. The grade of the cell toxicity ranged from I to II. On the 5th and 7th day the proliferative rate of osteoblasts on scaffolds in the composite materials was significantly higher than that in the control group. The activity of alkaline phosphatase was obviously higher than that in the control group on Day 1 and 3. Nano-hydroxyapatite and gelatin in certain proportions and under certain conditions can be prepared into a composite biomimetic porous scaffolds with high porosity and three-dimensional structure using freeze-drying method. The scaffold shows good biocompatibility with mouse osteoblasts and may be a novel scaffolds for bone tissue engineering.

Process for preparing a chemical compound enriched in isotope content

DOEpatents

Michaels, Edward D.

1982-01-01

A process to prepare a chemical enriched in isotope content which includes: (a) A chemical exchange reaction between a first and second compound which yields an isotopically enriched first compound and an isotopically depleted second compound; (b) the removal of a portion of the first compound as product and the removal of a portion of the second compound as spent material; (c) the conversion of the remainder of the first compound to the second compound for reflux at the product end of the chemical exchange reaction region; (d) the conversion of the remainder of the second compound to the first compound for reflux at the spent material end of the chemical exchange region; and the cycling of the additional chemicals produced by one conversion reaction to the other conversion reaction, for consumption therein. One of the conversion reactions is an oxidation reaction, and the energy that it yields is used to drive the other conversion reaction, a reduction. The reduction reaction is carried out in a solid polymer electrolyte electrolytic reactor. The overall process is energy efficient and yields no waste by-products.

Estimation of chemical carcass composition from 8th rib characteristics with Belgian blue double-muscled bulls.

PubMed

De Campeneere, S; Fiems, L O; Van de Voorde, G; Vanacker, J M; Boucque, C V; Demeyer, D I

1999-01-01

Characteristics from the 8th rib cut: chemical composition, tissue composition after dissection, specific gravity (SG) and m. longissimus thoracis (LT) composition, collected on 17 Belgian Blue double-muscled fattening bulls were used to generate equations for predicting chemical carcass composition. Carcass composition was best predicted from chemical analysis of the 8th rib cut and the empty body weight (EBW) of the bull. Carcass chemical fat content (CCF, kg) was predicted from the 8th rib cut fat content (ether extract, 8RF, kg) by the following regression: CCF=1.94+27.37 8RF (R(2)=0.957, RSD =9.89%). A higher coefficient was found for carcass water (CCW, kg) predicted from 8RF and EBW: CCW=-2.26+0.28 EBW-34.28 8RF (R(2)=0.997, RSD=1.48%). No parameter was found to improve the prediction of CCP from EBW solely: CCP=-0.86+0.08 EBW (R(2) =0.992, RSD=2.61%). Prediction equations based solely on LT composition had low R(2) values of between 0.38 and 0.67, whereas no significant equations were found using SG. However, equations based on EBW had R(2) values between 0.78 and 0.99. Chemical components of the 8th rib cut in combination with EBW are most useful in predicting the chemical composition of the carcass of Belgian-Blue double-muscled bulls.

Antioxidant activity, polyphenolic contents and essential oil composition of Pimpinella anisum L. as affected by zinc fertilizer.

PubMed

Tavallali, Vahid; Rahmati, Sadegh; Bahmanzadegan, Atefeh

2017-11-01

The antioxidant activity and essential oil content of plants may vary considerably with respect to environmental conditions, especially nutrient availability. Among micronutrients, zinc (Zn) is needed by plants in only small amounts but is crucial to plant development. This study aimed to evaluate the effects of Zn fertilization on the antioxidant activity, polyphenolic contents and essential oil composition of Pimpinella anisum fruit. Foliar application of Zn fertilizer considerably increased the number of detected essential oil components from 27 to 45. Zinc application at a rate of 0.2% (w/v) significantly enhanced the levels of β-bisabolene, germacrene D, n-decane and α-zingiberene, whereas the opposite trend was observed for (E)-anethole and geijerene. Application of 0.2% Zn considerably increased the levels of phenolic compounds, with chlorogenic acid showing the highest content among eight phenolic compounds detected in treated plants. The maximum antioxidant activity was achieved through application of 0.2% Zn fertilizer. These findings indicated that the quality and quantity of anise fruit essential oil components were significantly altered by application of low levels of Zn. After foliar application of Zn, polyphenolic contents as well as antioxidant activity of anise fruit increased. Using Zn fertilizer is an efficient method to improve the pharmaceutical and food properties of anise fruit. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Method of forming a chemical composition

DOEpatents

Bingham, Dennis N.; Wilding, Bruce M.; Klingler, Kerry M.; Zollinger, William T.; Wendt, Kraig M.

2007-10-09

A method of forming a chemical composition such as a chemical hydride is described and which includes the steps of selecting a composition having chemical bonds and which is capable of forming a chemical hydride; providing a source of hydrogen; and exposing the selected composition to an amount of ionizing radiation to encourage the changing of the chemical bonds of the selected composition, and chemically reacting the selected composition with the source of hydrogen to facilitate the formation of a chemical hydride.

Piezoresistivity, mechanisms and model of cement-based materials with CNT/NCB composite fillers

NASA Astrophysics Data System (ADS)

Zhang, Liqing; Ding, Siqi; Dong, Sufen; Li, Zhen; Ouyang, Jian; Yu, Xun; Han, Baoguo

2017-12-01

The use of conductive cement-based materials as sensors has attracted intense interest over past decades. In this paper, carbon nanotube (CNT)/nano carbon black (NCB) composite fillers made by electrostatic self-assembly are used to fabricate conductive cement-based materials. Electrical and piezoresistive properties of the fabricated cement-based materials are investigated. Effect of filler content, load amplitudes and rate on piezoresistive property within elastic regime and piezoresistive behaviors during compressive loading to destruction are explored. Finally, a model describing piezoresistive property of cement-based materials with CNT/NCB composite fillers is established based on the effective conductive path and tunneling effect theory. The research results demonstrate that filler content and load amplitudes have obvious effect on piezoresistive property of the composites materials, while load rate has little influence on piezoresistive property. During compressive loading to destruction, the composites also show sensitive piezoresistive property. Therefore, the cement-based composites can be used to monitor the health state of structures during their whole life. The built model can well describe the piezoresistive property of the composites during compressive loading to destruction. The good match between the model and experiment data indicates that tunneling effect actually contributes to piezoresistive phenomenon.

Carbon Materials Metal/Metal Oxide Nanoparticle Composite and Battery Anode Composed of the Same

NASA Technical Reports Server (NTRS)

Hung, Ching-Cheh (Inventor)

2006-01-01

A method of forming a composite material for use as an anode for a lithium-ion battery is disclosed. The steps include selecting a carbon material as a constituent part of the composite, chemically treating the selected carbon material to receive nanoparticles, incorporating nanoparticles into the chemically treated carbon material and removing surface nanoparticles from an outside surface of the carbon material with incorporated nanoparticles. A material making up the nanoparticles alloys with lithium.

Chemical composition and mineralogy of borate from Rio Grande deposit, Uyuni (Bolivia) as raw materials for industrial applications

NASA Astrophysics Data System (ADS)

Guillen Vargas, Julio; Arancibia, Jony Roger Hans; Alfonso, Pura; Garcia-Valles, Maite; Parcerisa, David; Martinez, Salvador

2014-05-01

Bolivia has large tailings as a result of the historic and present-day Sn mining activity developed extensively in that country. Tailings produced in these mining activities have an appropriate composition to reprocess them and make silicate glass and glass-ceramics, obtaining the valorization of wastes and reducing the visual and chemical impact. Reprocessing the wastes to make glass and glass-ceramics prevents the leaching of heavy metals from those wastes because they are retained in the structure of the glass. Furthermore, an option to increase the economic value of these glasses is the introduction of boron and other additives to produce borosilicate glass. In this study a characterization of the Rio Grande borate deposit for its use in the manufacture of borosilicate glass is presented. Mineralogy was determined by X-ray diffraction (XRD), and Fourier transforms infrared spectroscopy (FTIR); textures were observed by scanning electron microscopy (SEM) and chemical composition was determined by inductively coupled plasma mass spectrometry (ICP-MS). The Rio Grande borate deposit is located in an area of about 50 km2 close to the south of the Salar of Uyuni, in the Río Grande de Lípez Delta. Borates occur in the contact between fluvio-deltaic and lacustrine sediments from water raising the surface by capillarity. The borates crop out in an extent area but towards the west they are covered by fluvio-deltaic sediments, which can be up to 2 m thick. These borates occur as lenses 50-100 m in diameter and layers up to 1 m thick. They usually form brittle nodules with a cotton-ball texture. Chemical composition of the Rio Grande borates is CaO, 11.82-13.83 wt%; Na2O, 13.50-19.35 wt%; K2O, 0.05- 1.04 wt%; MgO, 0.42-1.46 wt%; B2O3, 36.21-42.60 wt%; SiO2, up to 0.53 wt% and SO2, up to 0.60 wt%. Trace elements are low: Sr content is between 151-786 ppm, Al 12-676 ppm, Mn between 1-17 ppm, As 2-10 ppm and Fe between 9-376 ppm. The most abundant borate mineral in this

Composition and conductance distributions of single GeSi quantum rings studied by conductive atomic force microscopy combined with selective chemical etching.

PubMed

Lv, Y; Cui, J; Jiang, Z M; Yang, X J

2013-02-15

Atomic force microscopy imaging combined with selective chemical etching is employed to quantitatively investigate three-dimensional (3D) composition distributions of single GeSi quantum rings (QRs). In addition, the 3D quantitative composition distributions and the corresponding conductance distributions are simultaneously obtained on the same single GeSi QRs by conductive atomic force microscopy combined with selective chemical etching, allowing us to investigate the correlations between the conductance and composition distributions of single QRs. The results show that the QRs' central holes have higher Ge content, but exhibit lower conductance, indicating that the QRs' conductance distribution is not consistent with their composition distribution. By comparing the topography, composition and conductance profiles of the same single QRs before and after different etching processes, it is found that the conductance distributions of GeSi QRs do not vary with the change of composition distribution. Instead, the QRs' conductance distributions are found to be consistent with their topographic shapes, which can be supposed to be due to the shape determined electronic structures.

Chemical analysis and biological testing of materials from the EDS coal liquefaction process: a status report

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

Later, D.W.; Pelroy, R.A.; Wilson, B.W.

1984-05-01

Representative process materials were obtained from the EDS pilot plant for chemical and biological analyses. These materials were characterized for biological activity and chemical composition using a microbial mutagenicity assay and chromatographic and mass spectrometric analytical techniques. The two highest boiling distillation cuts, as well as process solvent (PS) obtained from the bottoms recycle mode operation, were tested for initiation of mouse skin tumorigenicity. All three materials were active; the crude 800/sup 0 +/F cut was substantially more potent than the crude bottoms recycle PS or 750 to 800/sup 0/F distillate cut. Results from chemical analyses showed the EDS materials,more » in general, to be more highly alkylated and have higher hydroaromatic content than analogous SRC II process materials (no in-line process hydrogenation) used for comparison. In the microbial mutagenicity assays the N-PAC fractions showed greater activity than did the aliphatic hydrocarbon, hydroxy-PAH, or PAH fractions, although mutagenicity was detected in certain PAH fractions by a modified version of the standard microbial mutagenicity assay. Mutagenic activities for the EDS materials were lower, overall, than those for the corresponding materials from the SRC II process. The EDS materials produced under different operational modes had distinguishable differences in both their chemical constituency and biological activity. The primary differences between the EDS materials studied here and their SRC II counterparts used for comparison are most likely attributable to the incorporation of catalytic hydrogenation in the EDS process. 27 references, 28 figures, 27 tables.« less

Composite materials. Volume 3 - Engineering applications of composites. Volume 4 - Metallic matrix composites. Volume 8 - Structural design and analysis, Part 2

NASA Technical Reports Server (NTRS)

Noton, B. R. (Editor); Kreider, K. G.; Chamis, C. C.

1974-01-01

This volume discusses a vaety of applications of both low- and high-cost composite materials in a number of selected engineering fields. The text stresses the use of fiber-reinforced composites, along with interesting material systems used in the electrical and nuclear industries. As to technology transfer, a similarity is noted between many of the reasons responsible for the utilization of composites and those problems requiring urgent solution, such as mechanized fabrication processes and design for production. Features topics include road transportation, rail transportation, civil aircraft, space vehicles, builing industry, chemical plants, and appliances and equipment. The laminate orientation code devised by Air Force materials laboratory is included. Individual items are announced in this issue.

Aqueous fluid composition in CI chondritic materials: Chemical equilibrium assessments in closed systems

NASA Astrophysics Data System (ADS)

Zolotov, Mikhail Yu.

2012-08-01

Solids of nearly solar composition have interacted with aqueous fluids on carbonaceous asteroids, icy moons, and trans-neptunian objects. These processes altered mineralogy of accreted materials together with compositions of aqueous and gaseous phases. We evaluated chemistry of aqueous solutions coexisted with CI-type chondritic solids through calculations of chemical equilibria in closed water-rock-gas systems at different compositions of initial fluids, water/rock mass ratios (0.1-1000), temperatures (<350 °C), and pressures (<2 kbars). The calculations show that fluid compositions are mainly affected by solubilities of solids, the speciation of chlorine in initial water-rock mixtures, and the occurrence of Na-bearing secondary minerals such as saponite. The major species in modeled alkaline solutions are Na+, Cl-, CO32-,HCO3-, K+, OH-, H2, and CO2. Aqueous species of Mg, Fe, Ca, Mn, Al, Ni, Cr, S, and P are not abundant in these fluids owing to low solubility of corresponding solids. Typical NaCl type alkaline fluids coexist with saponite-bearing mineralogy that usually present in aqueously altered chondrites. A common occurrence of these fluids is consistent with the composition of grains emitted from Enceladus. Na-rich fluids with abundant CO32-,HCO3-, and OH- anions coexist with secondary mineralogy depleted in Na. The Na2CO3 and NaHCO3 type fluids could form via accretion of cometary ices. NaOH type fluids form in reduced environments and may locally occur on parent bodies of CR carbonaceous chondrites. Supposed melting of accreted HCl-bearing ices leads to early acidic fluids enriched in Mg, Fe and other metals, consistent with signs of low-pH alteration in chondrites. Neutralization of these solutions leads to alkaline Na-rich fluids. Sulfate species have negligible concentrations in closed systems, which remain reduced, especially at elevated pressures created by forming H2 gas. Hydrogen, CO2, and H2O dominate in the gaseous phase, though the abundance

Synthesis and physico-chemical characterization of a polysialate-hydroxyapatite composite for potential biomedical application

NASA Astrophysics Data System (ADS)

Zoulgami, M.; Lucas-Girot, A.; Michaud, V.; Briard, P.; Gaudé, J.; Oudadesse, H.

2002-09-01

New composite materials based on aluminosilicate materials were developed to be used in orthopaedic or maxillo-facial surgery. They are called geopolymers or polysialate-siloxo (PSS) and were studied alone or mixed with hydroxyapatite (HAP). The properties of these materials were investigated for potential use in biological or surgery applications. In this work, the chemistry involved in materials preparation was described. Samples were characterized by some physico-chemical methods like X-ray diffraction (XRD), infrared spectrometry (IR) and electron dispersion X-ray spectrometry (EDX). Results indicate that the mixing hydroxyapatite-geopolymer (PSS) leads to a neutral porous composite material with interesting physico-chemical properties. A preliminary evaluation of its cytotoxicity reveals an harmlessness towards fibroblasts. These properties allow to envisage this association as a potential biomaterial.

Isolation, purification and chemical composition of insoluble collagen from Guerin epithelioma.

PubMed

Bańkowski, E; Galasiński, W; Gindzieẃski, A; Rzeczycki, W

1975-01-01

1. The insoluble collagen from Guerin epithelioma was isolated and its chemical composition was determined. The unusually high histidine content is accompanied in tumour collagen by a relatively small amount of lysine and arginine. 2. The isolated protein was strongly bound to glycoprotein, which could not be removed by EDTA treatment unless this procedure was preceded by digestion of the complex with trypsin.

The effect of raw materials on thermo-oxidative stability and glycidyl ester content of palm oil during frying.

PubMed

Aniołowska, Magda A; Kita, Agnieszka M

2016-04-01

The objective of this research was to determine the effects of the water content of food incorporated into frying oil on oil degradation and the content of glycidyl esters. Potato chips, French fries and snacks were fried intermittently in palm oil, which was heated at 180 °C for 8 h per day over five consecutive days. Thermo-oxidative and physical alterations, changes in fatty acid composition, total polar components, polar fraction composition, and water content were analysed. The content of glycidyl esters was measured by liquid chromatography-tandem mass spectrometry. More polar compounds were formed in the oil used for frying chips (252 g kg(-1)) than for French fries (229 g kg(-1)) or snacks (196 g kg(-1)). Reductions in glycidyl esters were found in oils used for frying--greater for frying snacks and French fries (95% and 93%) than for potato chips (87%). The rate of decrease of glycidyl esters was correlated with frying parameters, most strongly with the concentrations of diacylglycerols (r = 0.98) and total polar components (r = -0.98). The raw material had a greater influence on polymerization conversion and glycidyl ester content than on hydrolytic and oxidative changes in the frying oil. © 2015 Society of Chemical Industry.

Chemical composition and lipoxygenase activity in soybeans (Glycine max L. Merr.) submitted to gamma irradiation

NASA Astrophysics Data System (ADS)

Barros, Érica Amanda de; Broetto, Fernando; Bressan, Dayanne F.; Sartori, Maria M. P.; Costa, Vladimir E.

2014-05-01

Soybeans are an important food due to their functional and nutritional characteristics. However, consumption by western populations is limited by the astringent taste of soybeans and their derivatives which results from the action of lipoxygenase, an enzyme activated during product processing. The aim of this study was to evaluate the effect of gamma irradiation on the chemical composition and specific activity of lipoxygenase in different soybean cultivars. Soybeans were stored in plastic bags and irradiated with doses of 2.5, 5 and 10 kGy. The chemical composition (moisture, protein, lipids, ashes, crude fiber, and carbohydrates) and lipoxygenase specific activity were determined for each sample. Gamma irradiation induced a small increase of protein and lipid content in some soybean cultivars, which did not exceed the highest content of 5% and 26%, respectively, when compared to control. Lipoxygenase specific activity decreased in the three cultivars with increasing gamma irradiation dose. In conclusion, the gamma irradiation doses used are suitable to inactivate part of lipoxygenase while not causing expressive changes in the chemical composition of the cultivars studied.

Strengthening materials specifications

NASA Astrophysics Data System (ADS)

Sampath, K.

2005-10-01

Continuing efforts to strengthen materials specifications readily recognize that a mere compliance with a materials specification only assures a material meeting or exceeding the minimum expectations explicitly detailed in the specification. Implicitly, such efforts also recognize that additional and specific client needs must be addressed as supplementary requirements and introduced during material procurement to reduce risks and assure enhanced performance. This article describes two U.S. Navy-related case studies that allowed further strengthening of the materials specification process, using newer methods and renewed understanding. The first case demonstrates the use of a constraints-based modeling approach to specify the chemical composition of high-performance welding electrodes for critical U.S. Navy applications. This approach helps to distinguish high-performance welding electrode chemical compositions from rich and lean welding electrode chemical compositions that might limit the operational envelope, reduce performance, or both, while increasing overall cost of fabrication but otherwise meet electrode specification requirements. The second case identifies that the size of an ingot could be an important factor while specifying the aluminum and sulfur contents of very large-size, heavy-gauge plates. Renewed understanding of melt fluidity issues associated with the solidification of very large-size ingots shows that deficiencies in through-thickness ductility of heavy-gauge plates are related to controlling aluminum and sulfur contents of the voluminous melt, notwithstanding explicit compliance with specification requirements.

Unusual chemical compositions of noctilucent-cloud particle nuclei

NASA Technical Reports Server (NTRS)

Hemenway, C. L.

1973-01-01

Two sounding rocket payloads were launched from the ESRO range in Sweden during a noctilucent cloud display. Large numbers of submicron particles were collected, most of which appear to be made up of a high density material coated with a low density material. Typical electron micrographs are shown. Particle chemical compositions have been measured by use of dispersive X-ray analysis equipment attached to an electron microscope and have revealed that most of the high density particle nuclei have atomic weights greater than iron.

Assessment of cocoa (Theobroma cacao L.) butter content and composition throughout fermentations.

PubMed

Servent, Adrien; Boulanger, Renaud; Davrieux, Fabrice; Pinot, Marie-Neige; Tardan, Eric; Forestier-Chiron, Nelly; Hue, Clotilde

2018-05-01

Cocoa fermentation is a crucial step for the development of cocoa aroma and precursors of high quality cocoa and by-products. This bioprocess has been studied for years to understand cocoa chemical changes but some matters concerning changes in fat content remain that are investigated in this work. Changes in the quantity (free and total fat), extractability and composition of cocoa butter were assessed in samples from Madagascar, the Dominican Republic and Ecuador. Increases in free fat content were highlighted in samples from each origin thanks to the use of the 'soxtec' solvent method, which preserves the integrity of the butter. A 4.71% increase in free fat was measured in the Ecuadorian samples fermented for 144 h. Conversely, total fat content remained stable throughout fermentation. Protein and polyphenol contents decreases were linked to fat content augmentation by a strong negative interaction. Triglyceride and total and linked fatty acid kinetics (0 to 6 days) of the butter remained statistically stable during fermentation, as did unsaponifiable matter. The origin of fermentation had a predominant and significant impact on composition, revealed by PCA. This work underlines and explains the importance of fermentation process in improving yield of fat that can be extracted while preserving the composition of this cocoa butter. This study highlights an interaction in cocoa unfermented or partially fermented beans. This phenomenon causes butter content retention but is slowly broken after 72 h fermentation. Therefore, fermentation appears to be also necessary to enhance the cocoa butter content extracted from the nibs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of Mg content on the thermal stability and mechanical behaviour of PLLA/Mg composites processed by hot extrusion.

PubMed

Cifuentes, S C; Lieblich, M; López, F A; Benavente, R; González-Carrasco, J L

2017-03-01

In the field of bioabsorbable composites for biomedical applications, extrusion has been employed as a method to prepare homogeneous blends of polymeric matrices with bioactive ceramic fillers. In this work, the suitability of processing poly-l-lactic acid/Magnesium (PLLA/Mg) composites by hot extrusion has been assessed by a systematic characterization of PLLA/Mg composites containing different amounts of Mg particles up to 7wt%. The results show that extrusion causes a reduction of almost 20% in the viscosity average molecular weight of PLLA, which further decreases with increasing Mg content. Extrusion gave always rise to a homogeneous distribution of Mg particles within the PLLA matrix. This composite processing was not compromised by the degradation of the polymeric matrix because the processing temperature was always below the onset degradation temperature. In the processing conditions employed in the present work, degradation of the composite slightly increases as more Mg is added up to 5wt%, but is very high at 7wt%. This was also evident from the mechanical behaviour, so that Mg particles improved the stiffness and compression strength of neat PLLA until 5wt% of Mg content, which dropped drastically when the material had 7wt% of Mg. The filler strengthening factor decreases with the increment in Mg content. In order to obtain an optimised contribution of Mg particles, a balance between thermal degradation and mechanical resistance of PLLA must be achieved. Copyright © 2016 Elsevier B.V. All rights reserved.

Piezoelectric Nanoparticle-Polymer Composite Materials

NASA Astrophysics Data System (ADS)

McCall, William Ray

Herein we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be synthesized and fabricated into complex microstructures using sugar-templating methods or optical printing techniques. Stretchable foams with excellent tunable piezoelectric properties are created by incorporating sugar grains directly into polydimethylsiloxane (PDMS) mixtures containing barium titanate (BaTiO3 -- BTO) nanoparticles and carbon nanotubes (CNTs), followed by removal of the sugar after polymer curing. Porosities and elasticity are tuned by simply adjusting the sugar/polymer mass ratio and the electrical performance of the foams showed a direct relationship between porosity and the piezoelectric outputs. User defined 2D and 3D optically printed piezoelectric microstructures are also fabricated by incorporating BTO nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate (PEGDA) and exposing to digital optical masks that can be dynamically altered. Mechanical-to-electrical conversion efficiency of the optically printed composite is enhanced by chemically altering the surface of the BTO nanoparticles with acrylate groups which form direct covalent linkages with the polymer matrix under light exposure. Both of these novel materials should find exciting uses in a variety of applications including energy scavenging platforms, nano- and microelectromechanical systems (NEMS/MEMS), sensors, and acoustic actuators.

Mechanical Properties of Calcium Fluoride-Based Composite Materials

PubMed Central

Kleczewska, Joanna; Pryliński, Mariusz; Podlewska, Magdalena; Sokołowski, Jerzy; Łapińska, Barbara

2016-01-01

Aim of the study was to evaluate mechanical properties of light-curing composite materials modified with the addition of calcium fluoride. The study used one experimental light-curing composite material (ECM) and one commercially available flowable light-curing composite material (FA) that were modified with 0.5–5.0 wt% anhydrous calcium fluoride. Morphology of the samples and uniformity of CaF2 distribution were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Mechanical properties were tested after 24-hour storage of specimens in dry or wet conditions. Stored dry ECM enriched with 0.5–1.0 wt% CaF2 showed higher tensile strength values, while water storage of all modified ECM specimens decreased their tensile strength. The highest Vickers hardness tested after dry storage was observed for 2.5 wt% CaF2 content in ECM. The addition of 2.0–5.0 wt% CaF2 to FA caused significant decrease in tensile strength after dry storage and overall tensile strength decrease of modified FA specimens after water storage. The content of 2.0 wt% CaF2 in FA resulted in the highest Vickers hardness tested after wet storage. Commercially available composite material (FA), unmodified with fluoride addition, demonstrated overall significantly higher mechanical properties. PMID:28004001

Chemical constituents and energy content of some latex bearing plants.

PubMed

Kalita, D; Saikia, C N

2004-05-01

The latex bearing plants Plumeria alba, Calotropis procera, Euphorbia nerrifolia, Nerium indicum and Mimusops elengi were evaluated as potential renewable sources of energy and chemicals. Plant parts (leaf, stem, bark) and also whole plants were analyzed for elemental composition, oil, polyphenol, hydrocarbons, crude protein, alpha-cellulose, lignin and ash. The dry biomass yields were between 4.47 and 13.74 kg/plant. The carbon contents in whole plants varied from 38.5% to 44.9%, while hydrogen and nitrogen contents varied from 5.86% to 6.72% and 1.26% to 2.34%, respectively. The bark of the plants contained the highest amount of hydrocarbons (1.78-3.93%) and the leaves contained the lowest amounts (0.26-1.82%). The unsaponifiable materials and fatty acids in the oil fractions of whole plants ranged from 22.8% to 56.4% and 24.7% to 58.7%, respectively. The highest gross heat value was exhibited by C. procera (6145 cal/g) and the lowest by N. indicum (4405 cal/g). Hydrocarbon fractions were characterized by IR and (1)H-NMR and by thermogravimetric analyses. The activation energy (E(a)) in the third stage of decomposition was the greatest in the hydrocarbon fraction obtained from M. elengi (16.40 kJ mol(-1)) and the lowest for C. procera (3.96 kJ mol(-1)). The study indicated that the plant species might be suitable as alternative source of hydrocarbons and other phytochemicals.

Physical-chemical properties of dental composites and adhesives containing silane-modified SBA-15.

PubMed

Martim, Gedalias Custódio; Kupfer, Vicente Lira; Moisés, Murilo Pereira; Dos Santos, Andressa; Buzzetti, Paulo Henrique Maciel; Rinaldi, Andrelson Wellington; Rubira, Adley Forti; Girotto, Emerson Marcelo

2018-04-01

The aim of this study was to synthesize and characterize mesoporous materials SBA-15 and SBA-15 modified with 3-(methacryloxy)-propyl-trimethoxysilane (MPS) to be used as inorganic filler in restorative dental composites and adhesives, and evaluate the main physical-chemical properties of the resulting material. The SBA-15 and SBA-15/MPS were characterized by FTIR, BET and X-Ray and combined with TEGDMA, bis-GMA and commercial spherical silica to produce dental composites. Afterwards, the mesoporous materials were combined with TEGDMA, bis-GMA and HEMA to make adhesives. To compare the results, composites and adhesives containing only commercial spherical silica were investigated. Some physical-chemical properties such as degree of conversion (DC), flexural strength (FS) and modulus (FM), water sorption and solubility (W sp and W sl ), specific area (BET), and the leachable components were evaluated. The SBA-15/MPS can be used to prepare dental restorative materials, with some foreseeable advantages compared with pure SBA-15 dental materials and with improved properties compared with commercial spherical silica dental materials. An important improvement was that the dental materials based on modified SBA-15 presented a reduction of approximately 60% in leaching of unreacted monomers extracted by solvent compared to the control group. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Possibility of Using Composite Nanoparticles in High Energy Materials

NASA Astrophysics Data System (ADS)

Komarova, M. V.; Vorozhtsov, A. B.; Wakutin, A. G.

2017-01-01

The effect of nanopowders on the burning rate varying with the metal content in mixtures of different high energy composition is investigated. Experiments were performed on compositions based on an active tetrazol binder and electroexplosive nanoaluminum with addition of copper, nickel, or iron nanopowders, and of Al-Ni, Al-Cu, or Al-Fe composite nanoparticles produced by electrical explosion of heterogeneous metal wires. The results obtained from thermogravimetric analysis of model metal-based compositions are presented. The advantages of the composite nanoparticles and the possibility of using them in high energy materials are discussed.

Sea urchin skeleton: Structure, composition, and application as a template for biomimetic materials

NASA Astrophysics Data System (ADS)

Shapkin, Nikolay P.; Khalchenko, Irina G.; Panasenko, Alexander E.; Drozdov, Anatoly L.

2017-07-01

SEM and optical microscopy, chemical and EDX analysis, XRD, and FT-IR spectroscopy of three sea urchins skeletons (tests) show that the test is a spongy stereom, consisting of calcite with high content of magnesium. The tests are composed of mineral-organic composite of calcite-magnesite crystals, coated with organic film, containing silicon in form of polyphenylsiloxane. In the test of sea urchin pore spaces are linked into united system of regular structure with structure motive period about 20 um. This developed three-dimensional structure was used as a template for polymer material based on polyferrofenilsiloxane [OSiC6H5OH]x[OSiC6H5O]y[OFeO]z, which is chemically similar to the native film, coating sea urchins skeleton.

27 CFR 19.326 - Spirits content of chemicals produced.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-Products § 19.326 Spirits content of chemicals produced. All chemicals produced, including chemical by... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Spirits content of chemicals produced. 19.326 Section 19.326 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND...

A strategy to synthesize graphene-incorporated lignin polymer composite materials with uniform graphene dispersion and covalently bonded interface engineering

NASA Astrophysics Data System (ADS)

Wang, Mei; Duong, Le Dai; Ma, Yifei; Sun, Yan; Hong, Sung Yong; Kim, Ye Chan; Suhr, Jonghwan; Nam, Jae-Do

2017-08-01

Graphene-incorporated polymer composites have been demonstrated to have excellent mechanical and electrical properties. In the field of graphene-incorporated composite material synthesis, there are two main obstacles: Non-uniform dispersion of graphene filler in the matrix and weak interface bonding between the graphene filler and polymer matrix. To overcome these problems, we develop an in-situ polymerization strategy to synthesize uniformly dispersed and covalently bonded graphene/lignin composites. Graphene oxide (GO) was chemically modified by 4,4'-methylene diphenyl diisocyanate (MDI) to introduce isocyanate groups and form the urethane bonds with lignin macromonomers. Subsequential polycondensation reactions of lignin groups with caprolactone and sebacoyl chloride bring about a covalent network of modified GO and lignin-based polymers. The flexible and robust lignin polycaprolactone polycondensate/modified GO (Lig-GOm) composite membranes are achieved after vacuum filtration, which have tunable hydrophilicity and electrical resistance according to the contents of GOm. This research transforms lignin from an abundant biomass into film-state composite materials, paving a new way for the utilization of biomass wastes.

Chemical composition of sediments from White Sea, Russian Arctic

NASA Astrophysics Data System (ADS)

Gamza, Olga; Shevchenko, Vladimir; Novigatsky, Aleksandr

2010-05-01

300 m) with silles and elevations (<20 m), and also numerous islands. Thus variety of sediment composition is observed here - from rules and gravels to fine-grained clay silts [1]. The map of distribution of chemical elements was created by using bulk composition data with the help of program ArcView. Mn distribution in sedimentation mass is largely determed by influence of redox diagenesis. Reactive form of Mn dominates over less moving, litogenic form in sedimation mass of White Sea. Litogenic form remains in sediment, reactive form moves into silt near-bottom water, resulting Mn migration both in sediment and near-bottom layer of marine water. Mn oxidizes on the contact with oxygen of marine water and alters into insoluble form MnO2, causing Mn enrichment of surface layer of sediments. Highly movable silt deposit MnO2 and enriched by Mn suspension are moved by underflow and accumulate in bottom depressions and in central part of the sea, which is quite wide from both places of original sedimentation and run off sources [2]. Thus, the interrelation between granulometric composition of sediment and materials concentration can be shown by the example of Mn. Local conditions, leading to accumulation of clastic components, are: 1. Rise of content in sand owning to separation of heavy minerals 2. Rise of content in surface, mainly sandy clay sediments owning to presence of concretions 3. Rise of content in lower bunches roof owning to diagenetic contraction. Authors thank academic Lisitsyn for encourage, Andrey Apletalin for valuable help, and everybody, who helped in field and laboratory research of the White sea sediments. Work was being done under the auspices of Russian foundation of basic research (grants 09-05-10081, 09-05-00658 and 08-05-00860), RSA presidiums program of 17 fundamental researches (project 17.1). References: 1.Kuzmina T., Lein A., Lutchsheva L., Murdmaa I., Novigatsky A., Shevchenko V. Chemical composition of White Sea's sediments // Litology and

Zirconia/Hydroxyapatite Composites Synthesized Via Sol-Gel: Influence of Hydroxyapatite Content and Heating on Their Biological Properties

PubMed Central

Bollino, Flavia; Armenia, Emilia; Tranquillo, Elisabetta

2017-01-01

Zirconia (ZrO2) and zirconia-based glasses and ceramics are materials proposed for use in the dental and orthopedic fields. In this work, ZrO2 glass was modified by adding different amounts of bioactive and biocompatible hydroxyapatite (HAp). ZrO2/HAp composites were synthesized via the sol-gel method and heated to different temperatures to induce modifications of their chemical structure, as ascertained by Fourier transform infrared spectroscopy (FTIR) analysis. The aim was to investigate the effect of both HAp content and heating on the biological performances of ZrO2. The materials’ bioactivity was studied by soaking samples in a simulated body fluid (SBF). FTIR and scanning electron microscopy (SEM)) analyses carried out after exposure to SBF showed that all materials are bioactive, i.e., they are able to form a hydroxyapatite layer on their surface. Moreover, the samples were soaked in a solution containing bovine serum albumin (BSA). FTIR analysis proved that the synthesized materials are able to adsorb the blood protein, the first step of cell adhesion. WST-8 ([2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt]) assay showed that no cytotoxicity effects were induced by the materials’ extract. However, the results proved that bioactivity increases with both the HAp content and the temperature used for the thermal treatment, whereas biocompatibility increases with heating but is not affected by the HAp content. PMID:28773116

Interspecies differences in the empty body chemical composition of domestic animals.

PubMed

Maeno, H; Oishi, K; Hirooka, H

2013-07-01

Domestication of animals has resulted in phenotypic changes by means of natural and human-directed selection. Body composition is important for farm animals because it reflects the status of energy reserves. Thus, there is the possibility that farm animals as providers of food have been more affected by human-directed selection for body composition than laboratory animals. In this study, an analysis was conducted to determine what similarities and differences in body composition occur between farm and laboratory animals using literature data obtained from seven comparative slaughter studies (n = 136 observations). Farm animals from four species (cattle, goats, pigs and sheep) were all castrated males, whereas laboratory animals from three species (dogs, mice and rats) comprised males and/or females. All animals were fed ad libitum. The allometric equation, Y = aX b , was used to determine the influence of species on the accretion rates of chemical components (Y, kg) relative to the growth of the empty body, fat-free empty body or protein weights (X, kg). There were differences between farm and laboratory animals in terms of the allometric growth coefficients for chemical components relative to the empty BW and fat-free empty BW (P < 0.01); farm animals had more rapid accretion rates of fat (P < 0.01) but laboratory animals had more rapid accretion rates of protein, water and ash (P < 0.01). In contrast, there was no difference in terms of the allometric growth coefficients for protein and water within farm animals (P > 0.2). The allometric growth coefficients for ash weight relative to protein weight for six species except sheep were not different from a value of 1 (P > 0.1), whereas that of sheep was smaller than 1 (P < 0.01). When compared at the same fat content of the empty body, the rate of change in water content (%) per unit change in fat content (%) was not different (P > 0.05) across farm animal species and similar ash-to-protein ratios were obtained

Improved composite material and method for production of improved composite material

NASA Technical Reports Server (NTRS)

Farley, Gary L. (Inventor)

1994-01-01

A laminated composite material with improved interlaminar strength and damage tolerance having short rods distributed evenly throughout the composite material perpendicular to the laminae is introduced. Each rod is shorter than the thickness of the finished laminate, but several times as long as the thickness of each lamina. The laminate is made by inserting short rods in layers of prepreg material, and then stacking and curing prepreg material with rods inserted therethrough.

Composition analysis by scanning femtosecond laser ultraprobing (CASFLU).

DOEpatents

Ishikawa, Muriel Y.; Wood, Lowell L.; Campbell, E. Michael; Stuart, Brent C.; Perry, Michael D.

2002-01-01

The composition analysis by scanning femtosecond ultraprobing (CASFLU) technology scans a focused train of extremely short-duration, very intense laser pulses across a sample. The partially-ionized plasma ablated by each pulse is spectrometrically analyzed in real time, determining the ablated material's composition. The steering of the scanned beam thus is computer directed to either continue ablative material-removal at the same site or to successively remove nearby material for the same type of composition analysis. This invention has utility in high-speed chemical-elemental, molecular-fragment and isotopic analyses of the microstructure composition of complex objects, e.g., the oxygen isotopic compositions of large populations of single osteons in bone.

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

1984-01-01

Progress is reported in studies of constituent materials composite materials, generic structural elements, processing science technology, and maintaining long-term structural integrity. Topics discussed include: mechanical properties of high performance carbon fibers; fatigue in composite materials; experimental and theoretical studies of moisture and temperature effects on the mechanical properties of graphite-epoxy laminates and neat resins; numerical investigations of the micromechanics of composite fracture; delamination failures of composite laminates; effect of notch size on composite laminates; improved beam theory for anisotropic materials; variation of resin properties through the thickness of cured samples; numerical analysis composite processing; heat treatment of metal matrix composites, and the RP-1 and RP2 gliders of the sailplane project.

Chemical properties and colors of fermenting materials in salmon fish sauce production.

PubMed

Nakano, Mitsutoshi; Sagane, Yoshimasa; Koizumi, Ryosuke; Nakazawa, Yozo; Yamazaki, Masao; Watanabe, Toshihiro; Takano, Katsumi; Sato, Hiroaki

2018-02-01

This data article reports the chemical properties (moisture, pH, salinity, and soluble solid content) and colors of fermenting materials in salmon fish sauce products. The fish sauce was produced by mixing salt with differing proportions of raw salmon materials and fermenting for three months; the salmon materials comprised flesh, viscera, an inedible portion, and soft roe. Chemical properties and colors of the unrefined fish sauce ( moromi ), and the refined fish sauce, were analyzed at one, two, and three months following the start of fermentation. Data determined for all products are provided in table format.

[Correlation between degree of conversion, microhardness and inorganic content in composites].

PubMed

Neves, Alisson Discacciati; Discacciati, José Augusto César; Orêfice, Rodrigo Lambert; Jansen, Wellington Corrêa

2002-01-01

The purpose of this study was to evaluate the correlation between degree of conversion and microhardness in dental composites, as well as the effect of the inorganic content and type of photo-curing unit on these parameters. Three indirect composites (Artglass, Solidex and Zeta LC) were polymerized by means of three different laboratorial units (UniXS, Solidilite and an experimental device). For each material, fifteen samples were prepared using a metal matrix. The degree of conversion was analyzed by means of infrared spectroscopy, and microhardness was also assessed. The inorganic content was measured by means of thermogravimetric analysis (TGA). The Pearson s test was carried out in order to determine correlations. The degree of conversion of Artglass ranged from 37.5% to 79.2%, and its microhardness, from 32.4 to 50.3 (r = 0.904). The degree of conversion of Solidex ranged from 41.2% to 60.4%, and its microhardness, from 33.3 to 44.1 (r = 0.707). The degree of conversion and the microhardness of Zeta LC ranged from 62.0% to 78.0% and from 22.6 to 33.6, respectively (r = 0.710). It was concluded that the utilization of different photo-curing units caused variations on the degree of conversion, as a result of specific characteristics of each unit. For each material, there was strong correlation between the degree of conversion and microhardness. In addition, when different materials were compared, microhardness was more affected by filler content than by the degree of conversion.

Physico-chemical characterisation of material fractions in residual and source-segregated household waste in Denmark.

PubMed

Götze, R; Pivnenko, K; Boldrin, A; Scheutz, C; Astrup, T Fruergaard

2016-08-01

Physico-chemical waste composition data are paramount for the assessment and planning of waste management systems. However, the applicability of data is limited by the regional, temporal and technical scope of waste characterisation studies. As Danish and European legislation aims for higher recycling rates evaluation of source-segregation and recycling chains gain importance. This paper provides a consistent up-to-date dataset for 74 physico-chemical parameters in 49 material fractions from residual and 24 material fractions from source-segregated Danish household waste. Significant differences in the physico-chemical properties of residual and source-segregated waste fractions were found for many parameters related to organic matter, but also for elements of environmental concern. Considerable differences in potentially toxic metal concentrations between the individual recyclable fractions within one material type were observed. This indicates that careful planning and performance evaluation of recycling schemes are important to ensure a high quality of collected recyclables. Rare earth elements (REE) were quantified in all waste fractions analysed, with the highest concentrations of REE found in fractions with high content of mineral raw materials, soil materials and dust. The observed REE concentrations represent the background concentration level in non-hazardous waste materials that may serve as a reference point for future investigations related to hazardous waste management. The detailed dataset provided here can be used for assessments of waste management solutions in Denmark and for the evaluation of the quality of recyclable materials in waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Preparation of sodium alginate-nanohydroxyapatite composite material for bone repair and its biocompatibility].

PubMed

Wang, Yanmei; He, Jiacai; Li, Quanli; Shen, Jijia

2014-02-01

To prepare sodium alginate-nanohydroxyapatite composite material and to explore its feasibility as a bone repair material. Sodium alginate-nanohydroxyapatite composite material was prepared using chemical cross-linking and freeze-drying technology. The composite was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and its porosity was measured by liquid displacement method. The fifth passage of bone marrow stromal stem cells (BMSCs) were incubated on the composite material and then growth was observed by inverted microscope and SEM. BMSCs were cultured with liquid extracts of the material, methyl thiazolyl tetrazolium (MTT) assay was used to calculate the relative growth rate (RGR) on 1, 3, 5 d and to evaluate the cytotoxicity. Fresh dog blood was added into the liquid extracts to conduct hemolysis test, the spectrophotometer was used to determine the optical density (OD) and to calculate the hemolysis rate. Sodium alginate-nanohydroxyapatite composite material displayed porosity, the porous pore rate was (88.6 +/- 4.5)%. BMSCs showed full stretching and vigorous growth under inverted microscope and SEM. BMSCs cultured with liquid extracts of the material had good activities. The toxicity of composite material was graded as 1. Hemolysis test results showed that the hemolysis rate of the composite material was 1.28%, thus meeting the requirement of medical biomaterials. The composite material fabricated in this study has high porosity and good biocompatibility.

Composition and Chemical Variability of Ivoirian Xylopia staudtii Leaf Oil.

PubMed

Yapi, Thierry Acafou; Boti, Jean Brice; Ahibo, Antoine Coffy; Sutour, Sylvain; Bighelli, Ange; Casanova, Joseph; Tomi, Félix

2015-06-01

The chemical composition of a leaf oil sample from Ivoirian Xylopia staudtii Engler & Diels (Annonaceae) has been investigated by a combination of chromatographic [GC(RI)] and spectroscopic (GC-MS, 13C NMR) techniques. Thirty-five components that accounted for 91.8% of the whole composition have been identified. The oil composition was dominated by the furanoguaiadienes furanoguaia-1,4-diene (39.0%) and furanoguaia-1,3-diene(7.5%), and by germacrene D (17.5%). The composition of twelve other leaf oil samples demonstrated qualitative homogeneity, but quantitative variability. Indeed, the contents of the major components varied substantially: furanoguaia-1,4-diene (24.7-51.7%) and germacrene D (5.9-24.8%). The composition of X. staudtii leaf oil is close to that of X. rubescens leaf oil but varied drastically from those of the essential oils isolated from other Xylopia species. 13C NMR spectroscopy appeared as a powerful and complementary tool for analysis of sesquiterpene-rich essential oils.

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

1982-01-01

The promise of filamentary composite materials, whose development may be considered as entering its second generation, continues to generate intense interest and applications activity. Fiber reinforced composite materials offer substantially improved performance and potentially lower costs for aerospace hardware. Much progress has been achieved since the initial developments in the mid 1960's. Rather limited applications to primary aircraft structure have been made, however, mainly in a material-substitution mode on military aircraft, except for a few experiments currently underway on large passenger airplanes in commercial operation. To fulfill the promise of composite materials completely requires a strong technology base. NASA and AFOSR recognize the present state of the art to be such that to fully exploit composites in sophisticated aerospace structures, the technology base must be improved. This, in turn, calls for expanding fundamental knowledge and the means by which it can be successfully applied in design and manufacture.

Material Property Characterization of Potential Nanocarbon Metal-Matrix Composite: An Investigational Study

NASA Astrophysics Data System (ADS)

Zavala, Mitchel

Metal-matrix composites (MMCs) are engineered combinations of two or more materials. Tailored properties are achieved by systematic combinations of different constituents. Specialized design and synthesis procedures allow unique sets of material properties in composites. Covetics are a new type of metal-matrix nano-composite (MMnC) material. These materials are formed from FCC metals which are super-saturated with up to 10 wt. % of activated nano-carbon powder. The idea is that the nano-carbon particles will enhance the material properties of the base metal matrix, however most of the physical and mechanical properties of covetics have not been well characterized. The foci of this study are to optimize the covetic casting synthesis process under controlled conditions, to understand and analyze the microstructures of the synthesized copper and aluminum covetic, to provide a thorough analysis of the chemical composition of the synthesized covetic materials, and to characterize physical and mechanical properties of both of these materials using meticulously prepared samples and test procedures.

Thermal Curing Process Monitoring of the Composite Material Using the FBG sensor

NASA Astrophysics Data System (ADS)

Zhang, Youhong; Chang, Xinlong; Zhang, Xiaojun; He, Xiangyong

2018-03-01

The raw composite material will suffer complex chemical and morphological changes during the thermal curing process, and it is difficult to monitor the curing process and curing effect. In this paper, the FBG sensor was embedded in the raw composite material to monitor the whole curing process. The experiment results showed that the FBG sensor can monitor the resin transformation and residual deformation of the composite material, and the FBG sensor can be applied to monitor the thermal curing process of the composite structure.

Chemically-bonded brick production based on burned clay by means of semidry pressing

NASA Astrophysics Data System (ADS)

Voroshilov, Ivan; Endzhievskaya, Irina; Vasilovskaya, Nina

2016-01-01

We presented a study on the possibility of using the burnt rocks of the Krasnoyarsk Territory for production of chemically-bonded materials in the form of bricks which are so widely used in multistory housing and private house construction. The radiographic analysis of the composition of burnt rock was conducted and a modifier to adjust the composition uniformity was identified. The mixing moisture content was identified and optimal amount at 13-15% was determined. The method of semidry pressing has been chosen. The process of obtaining moldings has been theoretically proved; the advantages of chemically-bonded wall materials compared to ceramic brick were shown. The production of efficient artificial stone based on material burnt rocks, which is comparable with conventionally effective ceramic materials or effective with cell tile was proved, the density of the burned clay-based cell tile makes up to 1630-1785 kg m3, with compressive strength of 13.6-20.0 MPa depending on the compression ratio and cement consumption, frost resistance index is F50, and the thermal conductivity in the masonry is λ = 0,459-0,546 W m * °C. The clear geometric dimensions of pressed products allow the use of the chemically-bonded brick based on burnt clay as a facing brick.

Comparative study of the chemical composition and mineral element content of Artocarpus heterophyllus and Treculia africana seeds and seed oils.

PubMed

Ajayi, Ibironke Adetolu

2008-07-01

A comparative study of Artocarpus heterophyllus and Treculia africana seeds, both of Moraceae family, was carried out to establish their chemical compositions and evaluate their mineral element content in order to investigate the possibility of using them for human and or animal consumption and also to examine if there is a relationship between the properties of these seeds. A. heterophyllus and T. africana are rich in protein; their protein contents are higher than those from high protein animal sources such as beef and marine fishes. Both seeds have high carbohydrate content and could act as source of energy for animals if included in their diets. The oil contents of the seeds are 11.39% and 18.54% for A. heterophyllus and T. africana, respectively. The oils are consistently liquid at room temperature. The results of the physicochemical properties of the two seeds are comparable to those of conventional oil seeds such as groundnut and palm kernel oils and could be useful for nutritional and industrial purposes. The seeds were found to be good sources of mineral elements. The result revealed potassium to be the prevalent mineral elements which are 2470.00 ppm and 1680.00 ppm for A. heterophyllus and T. africana, respectively followed by sodium, magnesium and then calcium. They also contain reasonable quantity of iron, in particular A. heterophyllus 148.50 ppm.

The Effect of Chemical Functionalization on Mechanical Properties of Nanotube/Polymer Composites

NASA Technical Reports Server (NTRS)

Odegard, G. M.; Frankland, S. J. V.; Gates, T. S.

2003-01-01

The effects of the chemical functionalization of a carbon nanotube embedded in a nanotube/polyethylene composite on the bulk elastic properties are presented. Constitutive equations are established for both functionalized and non-functionalized nanotube composites systems by using an equivalent-continuum modeling technique. The elastic properties of both composites systems are predicted for various nanotube lengths, volume fractions, and orientations. The results indicate that for the specific composite material considered in this study, most of the elastic stiffness constants of the functionalized composite are either less than or equal to those of the non-functionalized composite.

Composition/bandgap selective dry photochemical etching of semiconductor materials

DOEpatents

Ashby, Carol I. H.; Dishman, James L.

1987-01-01

A method of selectively photochemically dry etching a first semiconductor material of a given composition and direct bandgap Eg.sub.1 in the presence of a second semiconductor material of a different composition and direct bandgap Eg.sub.2, wherein Eg.sub.2 >Eg.sub.1, said second semiconductor material substantially not being etched during said method, comprises subjecting both materials to the same photon flux and to the same gaseous etchant under conditions where said etchant would be ineffective for chemical etching of either material were the photons not present, said photons being of an energy greater than Eg.sub.1 but less than Eg.sub.2, whereby said first semiconductor material is photochemically etched and said second material is substantially not etched.

Compositions for enhancing hydroysis of cellulosic material by cellulolytic enzyme compositions

DOEpatents

Quinlan, Jason; Xu, Feng; Sweeney, Matthew; Johansen, Katja Salomon

2014-09-30

The present invention relates to compositions comprising a GH61 polypeptide having cellulolytic enhancing activity and an organic compound comprising a carboxylic acid moiety, a lactone moiety, a phenolic moiety, a flavonoid moiety, or a combination thereof, wherein the combination of the GH61 polypeptide having cellulolytic enhancing activity and the organic compound enhances hydrolysis of a cellulosic material by a cellulolytic enzyme compared to the GH61 polypeptide alone or the organic compound alone. The present invention also relates to methods of using the compositions.

Composite material

DOEpatents

Hutchens, Stacy A [Knoxville, TN; Woodward, Jonathan [Solihull, GB; Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN

2012-02-07

A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

Composite material dosimeters

DOEpatents

Miller, Steven D.

1996-01-01

The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

DOEpatents

Lackey, Jr., Walter J.; Caputo, Anthony J.

1986-01-01

A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

Flaxseed hull: Chemical composition and antioxidant activity during development.

PubMed

Herchi, Wahid; Al Hujaili, Abdullah D; Sakouhi, Faouzi; Sebei, Khaled; Trabelsi, Hajer; Kallel, Habib; Boukhchina, Sadok

2014-01-01

Changes in the chemical composition and antioxidant activity of flaxseed hull during maturation were investigated. P129 hull variety was studied at four maturation stages (St1, St2, St3, and St4). Significant variation in proximate composition and flaxseed hull oil characteristics were observed. A significant increase in the carbohydrates content of the hull was observed during development. The main methyl esters were linolenic acid (48.95 - 51.52 %), oleic acid (20.27-23.41%) and linoleic acid (15.62-17.70%). The highest polyunsaturated fatty acids (PUFA) were found to be 67.14 % at the first stage of maturity (St1). Flaxseed hull oil was of good quality, containing an abundance of omega-3 essential fatty acids. The iodine value increased, while the saponification value of oil decreased during seed development. The decrease in ascorbic acid content was steady. The maximum level of total phenolic acid content (128.3 mg/100 g oil) was reached at 7 DAF. The antioxidant activity of oilseed was assessed by means of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay. Radical scavenging activity for green hull was 52.74% and mature hull was 69.32%.

Inorganic chemical composition and chemical reactivity of settled dust generated by the World Trade Center building collapse: Chapter 12

USGS Publications Warehouse

Plumlee, Geoffrey S.; Hageman, Philip L.; Lamothe, Paul J.; Ziegler, Thomas L.; Meeker, Gregory P.; Theodorakos, Peter M.; Brownfield, Isabelle; Adams, Monique G.; Swayze, Gregg A.; Hoefen, Todd M.; Taggart, Joseph E.; Clark, Roger N.; Wilson, S.; Sutley, Stephen J.

2009-01-01

Samples of dust deposited around lower Manhattan by the September 11, 2001, World Trade Center (WTC) collapse have inorganic chemical compositions that result in part from the variable chemical contributions of concrete, gypsum wallboard, glass fibers, window glass, and other materials contained in the buildings. The dust deposits were also modified chemically by variable interactions with rain water or water used in street washing and fire fighting. Chemical leach tests using deionized water as the extraction fluid show the dust samples can be quite alkaline, due primarily to reactions with calcium hydroxide in concrete particles. Calcium and sulfate are the most soluble components in the dust, but many other elements are also readily leached, including metals such as Al, Sb, Mo Cr, Cu, and Zn. Indoor dust samples produce leachates with higher pH, alkalinity, and dissolved solids than outdoor dust samples, suggesting most outdoor dust had reacted with water and atmospheric carbon dioxide prior to sample collection. Leach tests using simulated lung fluids as the extracting fluid suggest that the dust might also be quite reactive in fluids lining the respiratory tract, resulting in dissolution of some particles and possible precipitation of new phases such as phosphates, carbonates, and silicates. Results of these chemical characterization studies can be used by health scientists as they continue to track and interpret health effects resulting from the short-term exposure to the initial dust cloud and the longer-term exposure to dusts resuspended during cleanup.

Clouds Composition in Super-Earth Atmospheres: Chemical Equilibrium Calculations

NASA Astrophysics Data System (ADS)

Kempton, Eliza M.-R.; Mbarek, Rostom

2015-12-01

Attempts to determine the composition of super-Earth atmospheres have so far been plagued by the presence of clouds. Yet the theoretical framework to understand these clouds is still in its infancy. For the super-Earth archetype GJ 1214b, KCl, Na2S, and ZnS have been proposed as condensates that would form under the condition of chemical equilibrium, if the planet’s atmosphere has a bulk composition near solar. Condensation chemistry calculations have not been presented for a wider range of atmospheric bulk composition that is to be expected for super-Earth exoplanets. Here we provide a theoretical context for the formation of super-Earth clouds in atmospheres of varied composition by determining which condensates are likely to form, under the assumption of chemical equilibrium. We model super-Earth atmospheres assuming they are formed by degassing of volatiles from a solid planetary core of chondritic material. Given the atomic makeup of these atmospheres, we minimize the global Gibbs free energy of over 550 gases and condensates to obtain the molecular composition of the atmospheres over a temperature range of 350-3,000 K. Clouds should form along the temperature-pressure boundaries where the condensed species appear in our calculations. The super-Earth atmospheres that we study range from highly reducing to oxidizing and have carbon to oxygen (C:O) ratios that are both sub-solar and super-solar, thereby spanning a diverse range of atmospheric composition that is appropriate for low-mass exoplanets. Some condensates appear across all of our models. However, the majority of condensed species appear only over specific ranges of H:O and C:O ratios. We find that for GJ 1214b, KCl is the primary cloud-forming condensate at solar composition, in agreement with previous work. However, for oxidizing atmospheres, where H:O is less than unity, K2SO4 clouds form instead. For carbon-rich atmospheres with super-solar C:O ratios, graphite clouds additionally appear. At

Experimental analysis of electrical properties of composite materials

NASA Astrophysics Data System (ADS)

Fiala, L.; Rovnaník, P.; Černý, R.

2017-02-01

Dry cement-based composites are electrically non-conductive materials that behave in electric field like dielectrics. However, a relatively low amount of electrically conductive admixture significantly increases the electrical conductivity which extends applicability of such materials in practice. Therefore, they can be used as self-monitoring sensors controlling development of cracks; as sensors monitoring moisture content or when treated by an external electrical voltage as heat sources used for deicing of material's surface layer. Alkali-activated aluminosilicates (AAA), as competing materials to cement-based materials, are intensively investigated in the present due to their superior durability and environmental impact. Whereas the electrical properties of AAA are similar to those cement-based, they can be enhanced in the same way. In both cases, it is crucial to find a reasonable amount of electrically conductive phase to design composites with a sufficient electrical conductivity at an affordable price. In this paper, electrical properties of composites based on AAA binder and electrically conductive admixture represented by carbon nanotubes (CNT) are investigated. Measurements of electrical properties are carried out by means of 2-probes DC technique on nine types of samples; reference sample without the conductive phase and samples with CNT admixture in amount of 0.1 % - 2.5 % by vol. A significant increase of the electrical conductivity starts from the amount of 0.5 % CNT admixture and in case of 2.5 % CNT is about three orders of magnitude higher compared to the reference sample.

Wood Chemical Composition in Species of Cactaceae: The Relationship between Lignification and Stem Morphology

PubMed Central

Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos

2015-01-01

In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level. PMID:25880223

Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

PubMed

Reyes-Rivera, Jorge; Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos; Terrazas, Teresa

2015-01-01

In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.

Defects, strain relaxation, and compositional grading in high indium content InGaN epilayers grown by molecular beam epitaxy

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

Bazioti, C.; Kehagias, Th.; Pavlidou, E.

2015-10-21

We investigate the structural properties of a series of high alloy content InGaN epilayers grown by plasma-assisted molecular beam epitaxy, employing the deposition temperature as variable under invariant element fluxes. Using transmission electron microscopy methods, distinct strain relaxation modes were observed, depending on the indium content attained through temperature adjustment. At lower indium contents, strain relaxation by V-pit formation dominated, with concurrent formation of an indium-rich interfacial zone. With increasing indium content, this mechanism was gradually substituted by the introduction of a self-formed strained interfacial InGaN layer of lower indium content, as well as multiple intrinsic basal stacking faults andmore » threading dislocations in the rest of the film. We show that this interfacial layer is not chemically abrupt and that major plastic strain relaxation through defect introduction commences upon reaching a critical indium concentration as a result of compositional pulling. Upon further increase of the indium content, this relaxation mode was again gradually succeeded by the increase in the density of misfit dislocations at the InGaN/GaN interface, leading eventually to the suppression of the strained InGaN layer and basal stacking faults.« less

Chemical Weathering on Venus

NASA Astrophysics Data System (ADS)

Zolotov, Mikhail

2018-01-01

Chemical and phase compositions of Venus's surface could reflect history of gas- and fluid-rock interactions, recent and past climate changes, and a loss of water from the Earth's sister planet. The concept of chemical weathering on Venus through gas-solid type reactions has been established in 1960s after the discovery of hot and dense CO2-rich atmosphere inferred from Earth-based and Mariner 2 radio emission data. Initial works suggested carbonation, hydration, and oxidation of exposed igneous rocks and a control (buffering) of atmospheric gases by solid-gas type chemical equilibria in the near-surface lithosphere. Calcite, quartz, wollastonite, amphiboles, and Fe oxides were considered likely secondary minerals. Since the late 1970s, measurements of trace gases in the sub-cloud atmosphere by Pioneer Venus and Venera entry probes and Earth-based infrared spectroscopy doubted the likelihood of hydration and carbonation. The H2O gas content appeared to be low to allow a stable existence of hydrated and a majority of OH-bearing minerals. The concentration of SO2 was too high to allow the stability of calcite and Ca-rich silicates with respect to sulfatization to CaSO4. In 1980s, the supposed ongoing consumption of atmospheric SO2 to sulfates gained support by the detection of an elevated bulk S content at Venera and Vega landing sites. The induced composition of the near-surface atmosphere implied oxidation of ferrous minerals to magnetite and hematite, consistent with the infrared reflectance of surface materials. The likelihood of sulfatization and oxidation has been illustrated in modeling experiments at simulated Venus conditions. Venus's surface morphology suggests that hot surface rocks and fines of mainly mafic composition contacted atmospheric gases during several hundreds of millions years since a global volcanic resurfacing. Some exposed materials could have reacted at higher and lower temperatures in a presence of diverse gases at different altitudinal

Composition of LHB Comets and Their Influence on the Early Earth Atmosphere Composition

NASA Technical Reports Server (NTRS)

Tornow, C.; Kupper, S.; Ilgner, M.; Kuehrt, E.; Motschmann, U.

2011-01-01

Two main processes were responsible for the composition of this atmosphere: chemical evolution of the volatile fraction of the accretion material forming the planet and the delivery of gasses to the planetary surface by impactors during the late heavy bombardment (LHB). The amount and composition of the volatile fraction influences the outgassing of the Earth mantle during the last planetary formation period. A very weakened form of outgassing activity can still be observed today by examining the composition of volcanic gasses. An enlightenment of the second process is based on the sparse records of the LHB impactors resulting from the composition of meteorites, observed cometary comas, and the impact material found on the Moon. However, for an assessment of the influence of the outgassing on the one hand and the LHB event on the other, one has to supplement the observations with numerical simulations of the formation of volatiles and their incorporation into the accretion material which is the precursors of planetary matter, comets and asteroids. These simulations are performed with a combined hydrodynamic-chemical model of the solar nebula (SN). We calculate the chemical composition of the gas and dust phase of the SN. From these data, we draw conclusions on the upper limits of the water content and the amount of carbon and nitrogen rich volatiles incorporated later into the accretion material. Knowing these limits we determine the portion of major gas compounds delivered during the LHB and compare it with the related quantities of the outgassed species.

Optimisation of steam distillation extraction oil from onion by response surface methodology and its chemical composition.

PubMed

Wang, Zhao Dan; Li, Li Hua; Xia, Hui; Wang, Feng; Yang, Li Gang; Wang, Shao Kang; Sun, Gui Ju

2018-01-01

Oil extraction from onion was performed by steam distillation. Response surface methodology was applied to evaluate the effects of ratio of water to raw material, extraction time, zymolysis temperature and distillation times on yield of onion oil. The maximum extraction yield (1.779%) was obtained as following conditions: ratio of water to raw material was 1, extraction time was 2.5 h, zymolysis temperature was 36° and distillation time was 2.6 h. The experimental values agreed well with those predicted by regression model. The chemical composition of extracted onion oil under the optimum conditions was analysed by gas chromatography-mass spectrometry technology. The results showed that sulphur compounds, like alkanes, sulphide, alkenes, ester and alcohol, were the major components of onion oil.

Composition/bandgap selective dry photochemical etching of semiconductor materials

DOEpatents

Ashby, C.I.H.; Dishman, J.L.

1985-10-11

Disclosed is a method of selectively photochemically dry etching a first semiconductor material of a given composition and direct bandgap Eg/sub 1/ in the presence of a second semiconductor material of a different composition and direct bandgap Eg/sub 2/, wherein Eg/sub 2/ > Eg/sub 1/, said second semiconductor material substantially not being etched during said method. The method comprises subjecting both materials to the same photon flux and to the same gaseous etchant under conditions where said etchant would be ineffective for chemical etching of either material were the photons not present, said photons being of an energy greater than Eg/sub 1/ but less than Eg/sub 2/, whereby said first semiconductor material is photochemically etched and said second material is substantially not etched.

[Comparison of chemical composition between fresh and processed Bufonis Venenum by UPLC-TQ-MS].

PubMed

Wang, Zi-yue; Wang, Hong-lan; Zhou, Jing; Ma, Hong-yue; Gong, Yan; Yan, Wen-li; Qian, Da-wei

2015-10-01

Toad venom is the Bufo bufo gargarizans or B. melanostictus after the ears of the gland secretion, used in the treatment of various cancers in recent years. Research shows that the main anti-tumor components in bufadienolide. Bufadienolide have free type structure and conjunct type structure. To identify and clarify the difference between bufogenin and bufotoxin contained in Bufonis Venenum, which was from B. bufo gargarizans, an UPLC-TQ-MS method has been established. UPLC-TQ-MS method was used to identify and quantify the major bufadienolides in Bufonis Venenum. UPLC-TQ-MS assay with positive ion mode was performed on a Waters ACQUITY UPLC BEH C, (2.1 mm x 100 mm, 1.7 µm) with the mobile phase consisting of 0. 1% aqueous formic and acidacetonitrile in gradient elution at a flow rate of 0.4 mL · min⁻¹ and the column temperature was set at 35 °C. By comparing their retention time and high resolution mass data of Bufonis Venenum extracts, 37 effective components were primarily identified by MS/MS analysis in positive ion mode. Twenty-six of them were free-type bufadienolides (bufogenin), 11 of them were conjugated bufadienolides. There were significant differences in the main composition between fresh and processed Bufonis Venenum. The study found that the chemical composition of toad venom through great changes after processing, conjunct type content is much less, free type content as well change.

Estimation of wood density and chemical composition by means of diffuse reflectance mid-infrared Fourier transform (DRIFT-MIR) spectroscopy.

PubMed

Nuopponen, Mari H; Birch, Gillian M; Sykes, Rob J; Lee, Steve J; Stewart, Derek

2006-01-11

Sitka spruce (Picea sitchensis) samples (491) from 50 different clones as well as 24 different tropical hardwoods and 20 Scots pine (Pinus sylvestris) samples were used to construct diffuse reflectance mid-infrared Fourier transform (DRIFT-MIR) based partial least squares (PLS) calibrations on lignin, cellulose, and wood resin contents and densities. Calibrations for density, lignin, and cellulose were established for all wood species combined into one data set as well as for the separate Sitka spruce data set. Relationships between wood resin and MIR data were constructed for the Sitka spruce data set as well as the combined Scots pine and Sitka spruce data sets. Calibrations containing only five wavenumbers instead of spectral ranges 4000-2800 and 1800-700 cm(-1) were also established. In addition, chemical factors contributing to wood density were studied. Chemical composition and density assessed from DRIFT-MIR calibrations had R2 and Q2 values in the ranges of 0.6-0.9 and 0.6-0.8, respectively. The PLS models gave residual mean squares error of prediction (RMSEP) values of 1.6-1.9, 2.8-3.7, and 0.4 for lignin, cellulose, and wood resin contents, respectively. Density test sets had RMSEP values ranging from 50 to 56. Reduced amount of wavenumbers can be utilized to predict the chemical composition and density of a wood, which should allow measurements of these properties using a hand-held device. MIR spectral data indicated that low-density samples had somewhat higher lignin contents than high-density samples. Correspondingly, high-density samples contained slightly more polysaccharides than low-density samples. This observation was consistent with the wet chemical data.

Digitally tunable physicochemical coding of material composition and topography in continuous microfibres.

PubMed

Kang, Edward; Jeong, Gi Seok; Choi, Yoon Young; Lee, Kwang Ho; Khademhosseini, Ali; Lee, Sang-Hoon

2011-09-04

Heterotypic functional materials with compositional and topographical properties that vary spatiotemporally on the micro- or nanoscale are common in nature. However, fabricating such complex materials in the laboratory remains challenging. Here we describe a method to continuously create microfibres with tunable morphological, structural and chemical features using a microfluidic system consisting of a digital, programmable flow control that mimics the silk-spinning process of spiders. With this method we fabricated hydrogel microfibres coded with varying chemical composition and topography along the fibre, including gas micro-bubbles as well as nanoporous spindle-knots and joints that enabled directional water collection. We also explored the potential use of the coded microfibres for tissue engineering applications by creating multifunctional microfibres with a spatially controlled co-culture of encapsulated cells.

Effect of Chemical Treatments on Flax Fibre Reinforced Polypropylene Composites on Tensile and Dome Forming Behaviour

PubMed Central

Wang, Wentian; Lowe, Adrian; Kalyanasundaram, Shankar

2015-01-01

Tensile tests were performed on two different natural fibre composites (same constituent material, similar fibre fraction and thickness but different weave structure) to determine changes in mechanical properties caused by various aqueous chemical treatments and whether any permanent changes remain on drying. Scanning electronic microscopic examinations suggested that flax fibres and the flax/polypropylene interface were affected by the treatments resulting in tensile property variations. The ductility of natural fibre composites was improved significantly under wet condition and mechanical properties (elongation-to-failure, stiffness and strength) can almost retain back to pre-treated levels when dried from wet condition. Preheating is usually required to improve the formability of material in rapid forming, and the chemical treatments performed in this study were far more effective than preheating. The major breakthrough in improving the formability of natural fibre composites can aid in rapid forming of this class of material system. PMID:25789505

Sandwich-structured C/C-SiC composites fabricated by electromagnetic-coupling chemical vapor infiltration.

PubMed

Hu, Chenglong; Hong, Wenhu; Xu, Xiaojing; Tang, Sufang; Du, Shanyi; Cheng, Hui-Ming

2017-10-13

Carbon fiber (CF) reinforced carbon-silicon carbide (C/C-SiC) composites are one of the most promising lightweight materials for re-entry thermal protection, rocket nozzles and brake discs applications. In this paper, a novel sandwich-structured C/C-SiC composite, containing two exterior C/SiC layers, two gradient C/C-SiC layers and a C/C core, has been designed and fabricated by two-step electromagnetic-coupling chemical vapor infiltration (E-CVI) for a 20-hour deposition time. The cross-section morphologies, interface microstructures and SiC-matrix growth characteristics and compositions of the composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. Microstructure characterization indicates that the SiC growth includes an initial amorphous SiC zone, a gradual crystallization of SiC and grow-up of nano-crystal, and a columnar grain region. The sandwich structure, rapid deposition rate and growth characteristics are attributed to the formation of thermal gradient and the establishment of electromagnetic field in the E-CVI process. The composite possesses low density of 1.84 g/cm 3 , high flexural strength of 325 MPa, and low linear ablation rate of 0.38 μm/s under exposure to 5-cycle oxyacetylene flame for 1000 s at ~1700 °C.

Ultrathin Pt xSn 1–x Nanowires for Methanol and Ethanol Oxidation Reactions: Tuning Performance by Varying Chemical Composition

DOE PAGES

Li, Luyao; Liu, Haiqing; Qin, Chao; ...

2018-02-28

Pt-based alloys denote promising catalysts for the methanol oxidation reaction (MOR) and the ethanol oxidation reaction (EOR), due to their enhanced activity toward alcohol-oxidation reactions and reduced cost as compared with Pt alone. Among all of these binary systems, PtSn has been reported to exhibit superior methanol/ethanol oxidation activity. In this paper, we deliberatively tailor chemical composition, reduce size, and optimize morphology of the catalyst in an effort to understand structure–property correlations that can be used to improve upon the electrocatalytic activity of these systems. Previous work performed by our group suggested that Pt-based catalysts, possessing an ultrathin one-dimensional (1D)more » structure, dramatically promote both cathodic and anodic reactions with respect to their zero-dimensional (0D) counterparts. Herein, a novel set of ultrathin binary Pt–Sn 1D nanowire (NW) catalysts with rationally controlled chemical compositions, i.e., Pt 9Sn 1, Pt 8Sn 2, and Pt 7Sn 3, has been synthesized using a facile, room-temperature, wet-solution-based method. The crystallinity and chemical composition of these as-prepared samples were initially characterized using XRD, XPS, and EDX. Results revealed that this synthetic protocol could successfully generate PtSn alloys with purposely tunable chemical compositions. TEM and HRTEM verified the structural integrity of our ultrathin 1D NW morphology for our Pt 9Sn 1, Pt 8Sn 2, and Pt 7Sn 3 samples. The effects of varying Sn content within these alloy samples toward the electro-oxidation reaction of methanol and ethanol were probed using cyclic voltammetry (CV) in acidic media. Finally, within this series, we find that the optimized chemical composition for both the MOR and the EOR is Pt 7Sn 3.« less

Ultrathin Pt xSn 1–x Nanowires for Methanol and Ethanol Oxidation Reactions: Tuning Performance by Varying Chemical Composition

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

Li, Luyao; Liu, Haiqing; Qin, Chao

Pt-based alloys denote promising catalysts for the methanol oxidation reaction (MOR) and the ethanol oxidation reaction (EOR), due to their enhanced activity toward alcohol-oxidation reactions and reduced cost as compared with Pt alone. Among all of these binary systems, PtSn has been reported to exhibit superior methanol/ethanol oxidation activity. In this paper, we deliberatively tailor chemical composition, reduce size, and optimize morphology of the catalyst in an effort to understand structure–property correlations that can be used to improve upon the electrocatalytic activity of these systems. Previous work performed by our group suggested that Pt-based catalysts, possessing an ultrathin one-dimensional (1D)more » structure, dramatically promote both cathodic and anodic reactions with respect to their zero-dimensional (0D) counterparts. Herein, a novel set of ultrathin binary Pt–Sn 1D nanowire (NW) catalysts with rationally controlled chemical compositions, i.e., Pt 9Sn 1, Pt 8Sn 2, and Pt 7Sn 3, has been synthesized using a facile, room-temperature, wet-solution-based method. The crystallinity and chemical composition of these as-prepared samples were initially characterized using XRD, XPS, and EDX. Results revealed that this synthetic protocol could successfully generate PtSn alloys with purposely tunable chemical compositions. TEM and HRTEM verified the structural integrity of our ultrathin 1D NW morphology for our Pt 9Sn 1, Pt 8Sn 2, and Pt 7Sn 3 samples. The effects of varying Sn content within these alloy samples toward the electro-oxidation reaction of methanol and ethanol were probed using cyclic voltammetry (CV) in acidic media. Finally, within this series, we find that the optimized chemical composition for both the MOR and the EOR is Pt 7Sn 3.« less

Towards retrievals of aerosol chemical composition from satellite observations by POLDER/PARASOL polarimeter

NASA Astrophysics Data System (ADS)

Li, L.; Dubovik, O.; Derimian, Y.; Lapyonok, T.; Schuster, G. L.; Ducos, F.

2016-12-01

The information about composition of aerosols has a great importance for monitoring and understanding of climate and environment dynamics. Such information can be obtained using situ measurements or chemical transport models. However, in situ sampling has limited spatial and temporal coverage, while estimations have large uncertainties. The present work enables the monitoring of aerosol chemical species from space-borne observations, providing observationally-based results with spatial and temporal coverage. Following the ideas of Schuster et al.(2005, 2009, 2016), we retrieve chemical composition directly from remote sensing measurements without intermediate retrieval of the refractive index (in contrast with Schuster's approach). This approach is expected to reduce the influence of modeling uncertainties, and to provide additional constraints in situations where remote sensing observations do not have enough spectral sensitivity to refractive index. One of principal difficulties is the identification of an adequate model for linking refractive index to chemical composition. Therefore, the initial effort of this work has focused on identifying an optimal "chemical composition to refractive index" conversion model. With that purpose, we first tested the retrieval approach using a simplified volume-weighting model and updated by the Maxwell Garnett mixing model. This concept was incorporated into the GRASP algorithm designed to retrieve an extended set of atmospheric parameters from remote sensing observations. Then a series of sensitivity tests using synthetic data of POLDER/PARASOL were conducted, and followed by inversion of real PARASOL observations. The sensitivity tests showed that these two models allow the retrieval to distinguish amongst the assumed chemical species. Results obtained from real PARASOL data demonstrated good agreement with the optical characteristics provided by AERONET (e.g., r2 of AOT 0.9). The obtained patterns of chemical component

Strain-Detecting Composite Materials

NASA Technical Reports Server (NTRS)

Wallace, Terryl A. (Inventor); Smith, Stephen W. (Inventor); Piascik, Robert S. (Inventor); Horne, Michael R. (Inventor); Messick, Peter L. (Inventor); Alexa, Joel A. (Inventor); Glaessgen, Edward H. (Inventor); Hailer, Benjamin T. (Inventor)

2016-01-01

A composite material includes a structural material and a shape-memory alloy embedded in the structural material. The shape-memory alloy changes crystallographic phase from austenite to martensite in response to a predefined critical macroscopic average strain of the composite material. In a second embodiment, the composite material includes a plurality of particles of a ferromagnetic shape-memory alloy embedded in the structural material. The ferromagnetic shape-memory alloy changes crystallographic phase from austenite to martensite and changes magnetic phase in response to the predefined critical macroscopic average strain of the composite material. A method of forming a composite material for sensing the predefined critical macroscopic average strain includes providing the shape-memory alloy having an austenite crystallographic phase, changing a size and shape of the shape-memory alloy to thereby form a plurality of particles, and combining the structural material and the particles at a temperature of from about 100-700.degree. C. to form the composite material.

Chlorination of humic materials: Byproduct formation and chemical interpretations

USGS Publications Warehouse

Reckhow, D.A.; Singer, P.C.; Malcolm, R.L.

1990-01-01

Ten aquatic humic and fulvic acids were isolated and studied with respect to their reaction with chlorine. Yields of TOX, chloroform, trichloroacetic acid, dichloroacetic acid, dichloroacetonitrile, and 1,1,1-trichloropropanone were measured at pH 7 and 12. Humic acids produced higher concentrations than their corresponding fulvic acids of all byproducts except 1,1,1-trichloropropanone. Chlorine consumption and byproduct formation were related to fundamental chemical characteristics of the humic materials. A statistical model was proposed for activated aromatic content based on 13C NMR and base titration data. The values estimated from this model were found to be well correlated with chlorine consumption. Specific byproduct formation was related to UV absorbance, nitrogen content, or the activated aromatic content. ?? 1990 American Chemical Society.

Effect of irradiation on the patulin content and chemical composition of apple juice concentrate.

PubMed

Zegota, H; Zegota, A; Bachman, S

1988-09-01

The influence of ionizing radiation on the patulin content of apple juice concentrate was investigated. The results indicated that patulin, at an initial concentration of about 2 mg/kg, disappeared after irradiation of the concentrate with doses as low as 2.5 kGy. For lower doses, the extent of patulin degradation was proportional to the absorbed dose. Irradiation of the concentrate with doses sufficient for patulin disappearance did not change the titratable acidity, the content of reducing sugars and carbonyl compounds or the amino acid composition. The content of ascorbic acid slightly decreased and the colour of the concentrate brightened. The intensity of the patulin absorption spectra after irradiation of mycotoxin in aqueous solutions decreased.

Composite structural materials

NASA Technical Reports Server (NTRS)

Loewy, R. G.; Wiberley, S. E.

1985-01-01

Various topics relating to composite structural materials for use in aircraft structures are discussed. The mechanical properties of high performance carbon fibers, carbon fiber-epoxy interface bonds, composite fractures, residual stress in high modulus and high strength carbon fibers, fatigue in composite materials, and the mechanical properties of polymeric matrix composite laminates are among the topics discussed.

Lignin composition is more important than content for maize stem cell wall degradation.

PubMed

He, Yuan; Mouthier, Thibaut Mb; Kabel, Mirjam A; Dijkstra, Jan; Hendriks, Wouter H; Struik, Paul C; Cone, John W

2018-01-01

The relationship between the chemical and molecular properties - in particular the (acid detergent) lignin (ADL) content and composition expressed as the ratio between syringyl and guaiacyl compounds (S:G ratio) - of maize stems and in vitro gas production was studied in order to determine which is more important in the degradability of maize stem cell walls in the rumen of ruminants. Different internodes from two contrasting maize cultivars (Ambrosini and Aastar) were harvested during the growing season. The ADL content decreased with greater internode number within the stem, whereas the ADL content fluctuated during the season for both cultivars. The S:G ratio was lower in younger tissue (greater internode number or earlier harvest date) in both cultivars. For the gas produced between 3 and 20 h, representing the fermentation of cell walls in rumen fluid, a stronger correlation (R 2 = 0.80) was found with the S:G ratio than with the ADL content (R 2 = 0.68). The relationship between ADL content or S:G ratio and 72-h gas production, representing total organic matter degradation, was weaker than that with gas produced between 3 and 20 h. The S:G ratio plays a more dominant role than ADL content in maize stem cell wall degradation. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Microfluidic Synthesis of Composite Cross-Gradient Materials for Investigating Cell–Biomaterial Interactions

PubMed Central

He, Jiankang; Du, Yanan; Guo, Yuqi; Hancock, Matthew J.; Wang, Ben; Shin, Hyeongho; Wu, Jinhui; Li, Dichen; Khademhosseini, Ali

2010-01-01

Combinatorial material synthesis is a powerful approach for creating composite material libraries for the high-throughput screening of cell–material interactions. Although current combinatorial screening platforms have been tremendously successful in identifying target (termed “hit”) materials from composite material libraries, new material synthesis approaches are needed to further optimize the concentrations and blending ratios of the component materials. Here we employed a microfluidic platform to rapidly synthesize composite materials containing cross-gradients of gelatin and chitosan for investigating cell–biomaterial interactions. The microfluidic synthesis of the cross-gradient was optimized experimentally and theoretically to produce quantitatively controllable variations in the concentrations and blending ratios of the two components. The anisotropic chemical compositions of the gelatin/chitosan cross-gradients were characterized by Fourier transform infrared spectrometry and X-ray photoelectron spectrometry. The three-dimensional (3D) porous gelatin/chitosan cross-gradient materials were shown to regulate the cellular morphology and proliferation of smooth muscle cells (SMCs) in a gradient-dependent manner. We envision that our microfluidic cross-gradient platform may accelerate the material development processes involved in a wide range of biomedical applications. PMID:20721897

Properties of carbon composite paper derived from coconut coir as a function of polytetrafluoroethylene content

NASA Astrophysics Data System (ADS)

Destyorini, Fredina; Indriyati; Indayaningsih, Nanik; Prihandoko, Bambang; Zulfia Syahrial, Anne

2018-03-01

The carbon composite papers were produced by utilizing carbon materials from coconut coir. In the present work, carbon composite papers (CCP) were prepared by mixing carbon materials in the form of powder and fibre with polymer (ethylene vinyl acetate and polyethylene glycol) in xylene at 100°C. Then, polytetrafluoroethylene (PTFE) with different content was used to treat the surface of CCP. The properties of PTFE-coated CCP were analysed by means of contact angle measurement, tensile testing, porosity, density, and electrical conductivity measurements. As expected, all CCP’s surfaces treated with PTFE were found to be hydrophobic with contact angle >120° and relatively constant during 60 minutes measurement. Furthermore, water contact angle, density, and mechanical properties of CCP generally increase with increasing PTFE content. However, the porosity and electrical conductivity of CCP decrease slightly as the PTFE content increased from 0 wt% to 30 wt%. Based on the observation and analysis, the optimum PTFE content on CCP was 20 %, in which the mechanical properties and hydrophobicity behaviour were improved significantly, but it was only caused a very small drop in porosity and electrical conductivity

Carbon Nano Tube Composites with Chemically Functionalized Plant Oils

NASA Astrophysics Data System (ADS)

Thielemans, Wim; Wool, Richard P.; Blau, Werner; Barron, Valerie

2003-03-01

Carbon Nano Tube Composites with Chemically Functionalized Plant Oil Wim Thielemans, R., P. Wool, V. Barron and W. Blau Multi-Wall Carbon Nano Tubes (MWCNT) made by the Kratchmer-Huffman CCVD process were found to interact and solubilize by slow mechanical stirring, with chemically functionalized plant oils, such as acrylated, epoxidized and maleinated triglycerides (TG) derived from plant oils. The chemical functionality on the TG imparted amphiphilic properties to the oils which allows them to self-assemble on the nanotubes, promoting both dissolution and the ability to make nanocomposites with unusual properties. Once in solution, the MWCT can be processed in a variety of methods, in particular to make composites with enhanced mechanical, fracture and thermal properties. Since the tensile modulus of MWs is about 1 TPa and a vector percolation analysis indicated tensile strengths of 50-100 GPa, we obtain significantly improved properties with even small amounts (1-3the glass transition temperature of the composite by about 20 oC, and the tensile modulus by about 11significant effects on the fracture stress can be obtained due to the both the influence of the strength and length of the MWNT at the crack tip. The ability of the oils to self-assemble on the carbon nanotube surfaces also makes them ideal candidates for self-healing materials. The properties with different functionalized oils will be reported. Supported by EPA, DoE and ISF

Formation of anodic layers on InAs (111)III. Study of the chemical composition

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

Valisheva, N. A., E-mail: valisheva@thermo.isp.nsc.ru; Tereshchenko, O. E.; Prosvirin, I. P.

2012-04-15

The chemical composition of {approx}20-nm-thick anodic layers grown on InAs (111)III in alkaline and acid electrolytes containing or not containing NH{sub 4}F is studied by X-ray photoelectron spectroscopy. It is shown that the composition of fluorinated layers is controlled by the relation between the concentrations of fluorine and hydroxide ions in the electrolyte and by diffusion processes in the growing layer. Fluorine accumulates at the (anodic layer)/InAs interface. Oxidation of InAs in an acid electrolyte with a low oxygen content and a high NH{sub 4}F content brings about the formation of anodic layers with a high content of fluorine andmore » elemental arsenic and the formation of an oxygen-free InF{sub x}/InAs interface. Fluorinated layers grown in an alkaline electrolyte with a high content of O{sup 2-} and/or OH{sup -} groups contain approximately three times less fluorine and consist of indium and arsenic oxyfluorides. No distinction between the compositions of the layers grown in both types of fluorine-free electrolytes is established.« less

HDPE-HA composites synthetized by in situ polymerization with different filler content

NASA Astrophysics Data System (ADS)

Hermán, V.; Karam, A.; Albano, C.; Romero, K.; González, G.

2012-07-01

In Situ ethylene polymerization was used to synthesize high density polyethylene - hydroxyapatite (HDPE-HA) composites, employing Cp2ZrCl2/MAO as catalytic system. A good dispersion of HA into the HDPE matrix was obtained when the following synthesis conditions were combined: high stirring velocities (2000 rpm), low quantities of solvent (100 mL), and 10 °C. Under these conditions different filler content was used to synthetized HDPE-HA composites. An interaction between HA and HDPE was obtained by FTIR. On the other hand, thermal analysis indicated that no significant differences were observed between HDPE and the composites.

Preparation and Enhanced Thermoelectric Performance of Cu2Se-SnSe Composite Materials

NASA Astrophysics Data System (ADS)

Peng, Zhi; He, Danqi; Mu, Xin; Zhou, Hongyu; Li, Cuncheng; Ma, Shifang; Ji, Pengxia; Hou, Weikang; Wei, Ping; Zhu, Wanting; Nie, Xiaolei; Zhao, Wenyu

2018-03-01

A series of p-type xCu2Se-SnSe (x = 0%, 0.10%, 0.15%, 0.20%, and 0.25%) composite thermoelectric materials have been prepared by the combination of ultrasonic dispersion and spark plasma sintering methods. The effects of secondary phase Cu2Se on the phase composition, microstructure, and thermoelectric properties of the composites were investigated. Microstructure characterization and elemental maps indicated Cu2Se grains uniformly distributed on the boundaries of the matrix. Transport measurements demonstrated that enhancement of the power factor and reduction of the thermal conductivity can be realized simultaneously by optimizing the adding content of Cu2Se. The highest ZT value of 0.51 at 773 K was achieved for the sample with x = 0.15%, increased by 24% compared with that of the SnSe matrix. These results demonstrate that optimizing the Cu2Se content can improve the thermoelectric performance of p-type SnSe polycrystalline materials.

Preparation and Enhanced Thermoelectric Performance of Cu2Se-SnSe Composite Materials

NASA Astrophysics Data System (ADS)

Peng, Zhi; He, Danqi; Mu, Xin; Zhou, Hongyu; Li, Cuncheng; Ma, Shifang; Ji, Pengxia; Hou, Weikang; Wei, Ping; Zhu, Wanting; Nie, Xiaolei; Zhao, Wenyu

2018-06-01

A series of p-type xCu2Se-SnSe ( x = 0%, 0.10%, 0.15%, 0.20%, and 0.25%) composite thermoelectric materials have been prepared by the combination of ultrasonic dispersion and spark plasma sintering methods. The effects of secondary phase Cu2Se on the phase composition, microstructure, and thermoelectric properties of the composites were investigated. Microstructure characterization and elemental maps indicated Cu2Se grains uniformly distributed on the boundaries of the matrix. Transport measurements demonstrated that enhancement of the power factor and reduction of the thermal conductivity can be realized simultaneously by optimizing the adding content of Cu2Se. The highest ZT value of 0.51 at 773 K was achieved for the sample with x = 0.15%, increased by 24% compared with that of the SnSe matrix. These results demonstrate that optimizing the Cu2Se content can improve the thermoelectric performance of p-type SnSe polycrystalline materials.

Urban stormwater runoff drives denitrifying community composition through changes in sediment texture and carbon content.

PubMed

Perryman, Shane E; Rees, Gavin N; Walsh, Christopher J; Grace, Michael R

2011-05-01

The export of nitrogen from urban catchments is a global problem, and denitrifying bacteria in stream ecosystems are critical for reducing in-stream N. However, the environmental factors that control the composition of denitrifying communities in streams are not well understood. We determined whether denitrifying community composition in sediments of nine streams on the eastern fringe of Melbourne, Australia was correlated with two measures of catchment urban impact: effective imperviousness (EI, the proportion of a catchment covered by impervious surfaces with direct connection to streams) or septic tank density (which affects stream water chemistry, particularly stream N concentrations). Denitrifying community structure was examined by comparing terminal restriction fragment length polymorphisms of nosZ genes in the sediments, as the nosZ gene codes for nitrous oxide reductase, the last step in the denitrification pathway. We also determined the chemical and physical characteristics of the streams that were best correlated with denitrifying community composition. EI was strongly correlated with community composition and sediment physical and chemical properties, while septic tank density was not. Sites with high EI were sandier, with less fine sediment and lower organic carbon content, higher sediment cations (calcium, sodium and magnesium) and water filterable reactive phosphorus concentrations. These were also the best small-scale environmental variables that explained denitrifying community composition. Among our study streams, which differed in the degree of urban stormwater impact, sediment grain size and carbon content are the most likely drivers of change in community composition. Denitrifying community composition is another in a long list of ecological indicators that suggest the profound degradation of streams is caused by urban stormwater runoff. While the relationships between denitrifying community composition and denitrification rates are yet to be

New Design Concept for an Excavator Arms by Using Composite Material

NASA Astrophysics Data System (ADS)

Solazzi, L.; Assi, A.; Ceresoli, F.

2018-06-01

The purpose of the present paper is to lightweight design an excavator arms, by using a different materials and in particular composite material. Specifically, the research is based on the study of a commercial excavator, by determining its geometry and analyzing the load conditions to which it is exposed. These are determined in relation to either the load diagram of the machine or the possible utilities of the excavator, such as the rotation of the machine. The materials used and implemented in the different analytical and numerical elaborations are classic construction steel S 355 (UNI EN 10025-3), high-resistance steel S 890 (UNI EN 10025-6), aluminum Al 6063 T6 (UNI EN 573-3) and the composite material made by carbon fiber and epoxy resin. The adopted constraints for the design of new arms with different materials, non-conventional for these applications, are numerous. The new solutions must present a safety factor either with respect to the yield tensile strength or to the critical load of buckling greater than or equal to the one determined for the excavator in its original geometrical conformation. Another criterion, which has heavily conditioned the geometry of the arms, was given by the fact that the developed solutions must present a very similar value of the maximum displacement in the different load conditions analyzed. A new geometry for arms made by composite material was developed. It was an elliptical conic section, instead of the classic rectangular section, in order to use the filament winding technological process. As for the adoption of the composite material, we focused on the study and the design of this material as long as the interaction with the extremities (made of aluminum) which are interfaced either with the link between the arms or with the elements of the hydraulic plant which serves for the arms movement. From the results developed, it emerges that the solution developed by adopting composite materials is the one that permits the

Post-irradiation hardness development, chemical softening, and thermal stability of bulk-fill and conventional resin-composites.

PubMed

Alshali, Ruwaida Z; Salim, Nesreen A; Satterthwaite, Julian D; Silikas, Nick

2015-02-01

To measure bottom/top hardness ratio of bulk-fill and conventional resin-composite materials, and to assess hardness changes after dry and ethanol storage. Filler content and kinetics of thermal decomposition were also tested using thermogravimetric analysis (TGA). Six bulk-fill (SureFil SDR, Venus bulk fill, X-tra base, Filtek bulk fill flowable, Sonic fill, and Tetric EvoCeram bulk-fill) and eight conventional resin-composite materials (Grandioso flow, Venus Diamond flow, X-flow, Filtek Supreme Ultra Flowable, Grandioso, Venus Diamond, TPH Spectrum, and Filtek Z250) were tested (n=5). Initial and 24h (post-cure dry storage) top and bottom microhardness values were measured. Microhardness was re-measured after the samples were stored in 75% ethanol/water solution. Thermal decomposition and filler content were assessed by TGA. Results were analysed using one-way ANOVA and paired sample t-test (α=0.05). All materials showed significant increase of microhardness after 24h of dry storage which ranged from 100.1% to 9.1%. Bottom/top microhardness ratio >0.9 was exhibited by all materials. All materials showed significant decrease of microhardness after 24h of storage in 75% ethanol/water which ranged from 14.5% to 74.2%. The extent of post-irradiation hardness development was positively correlated to the extent of ethanol softening (R(2)=0.89, p<0.001). Initial thermal decomposition temperature assessed by TGA was variable and was correlated to ethanol softening. Bulk-fill resin-composites exhibit comparable bottom/top hardness ratio to conventional materials at recommended manufacturer thickness. Hardness was affected to a variable extent by storage with variable inorganic filler content and initial thermal decomposition shown by TGA. The manufacturer recommended depth of cure of bulk-fill resin-composites can be reached based on the microhardness method. Characterization of the primary polymer network of a resin-composite material should be considered when

Chemical compositions, methods of making the chemical compositions, and structures made from the chemical compositions

DOEpatents

Yang, Lei; Cheng, Zhe; Liu, Ze; Liu, Meilin

2015-01-13

Embodiments of the present disclosure include chemical compositions, structures, anodes, cathodes, electrolytes for solid oxide fuel cells, solid oxide fuel cells, fuel cells, fuel cell membranes, separation membranes, catalytic membranes, sensors, coatings for electrolytes, electrodes, membranes, and catalysts, and the like, are disclosed.

Aerogel/polymer composite materials

NASA Technical Reports Server (NTRS)

Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

2010-01-01

The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

Aerogel / Polymer Composite Materials

NASA Technical Reports Server (NTRS)

Smith, Trent M. (Inventor); Clayton, LaNetra M. (Inventor); Fesmire, James E. (Inventor); Williams, Martha K. (Inventor); Roberson, Luke B. (Inventor)

2017-01-01

The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

Chemically-bonded brick production based on burned clay by means of semidry pressing

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

Voroshilov, Ivan, E-mail: Nixon.06@mail.ru; Endzhievskaya, Irina, E-mail: icaend@mail.ru; Vasilovskaya, Nina, E-mail: icaend@mail.ru

We presented a study on the possibility of using the burnt rocks of the Krasnoyarsk Territory for production of chemically-bonded materials in the form of bricks which are so widely used in multistory housing and private house construction. The radiographic analysis of the composition of burnt rock was conducted and a modifier to adjust the composition uniformity was identified. The mixing moisture content was identified and optimal amount at 13-15% was determined. The method of semidry pressing has been chosen. The process of obtaining moldings has been theoretically proved; the advantages of chemically-bonded wall materials compared to ceramic brick weremore » shown. The production of efficient artificial stone based on material burnt rocks, which is comparable with conventionally effective ceramic materials or effective with cell tile was proved, the density of the burned clay-based cell tile makes up to 1630-1785 kg \\ m{sup 3}, with compressive strength of 13.6-20.0 MPa depending on the compression ratio and cement consumption, frost resistance index is F50, and the thermal conductivity in the masonry is λ = 0,459-0,546 W \\ m {sup *} °C. The clear geometric dimensions of pressed products allow the use of the chemically-bonded brick based on burnt clay as a facing brick.« less

Effect of gamma-irradiation on aflatoxin B1 production by Aspergillus flavus and chemical composition of three crop seeds.

PubMed

Aziz, Nagy H; Mahrous, Souzan R

2004-06-01

The effect of gamma-irradiation on aflatoxin B1 production by Aspergillus flavus, and the chemical composition of some different crop seeds were investigated. A. flavus infected seeds behaved differently according to their principal constituents. A. flavus caused an increase in protein and decrease in lipids and carbohydrate contents of wheat, soyabean and fababean seeds. Growth of A. flavus and production of aflatoxin B1 was inhibited at a dose level of 5 kGy. A. flavus utilizes carbohydrates of seeds for its growth and aflatoxin production. Crops were arranged, in descending order, according to aflatoxin produced in seeds as wheat > soyabean > fababean. There were no changes in chemical constituents of irradiated seeds, such as protein, lipids, and carbohydrates.

Functionalization of Graphene Oxide and its Composite with Poly(3,4-ethylenedioxythiophene) as Electrode Material for Supercapacitors

NASA Astrophysics Data System (ADS)

Wang, Minchao; Jamal, Ruxangul; Wang, Yujie; Yang, Lei; Liu, Fangfang; Abdiryim, Tursun

2015-09-01

In this study, poly(3,4-ethylenedioxythiophene)/thiophene-grafted graphene oxide (PEDOT/Th-GO) composites from covalently linking of Th-GO with PEDOT chains were prepared via in situ chemical polymerization with different weight percentage of Th-GO ranging between 40 and 70 % in reaction medium. The resulting composite materials were characterized using a various analytical techniques. The structural analysis showed that the composites displayed a higher degree of conjugation and thermal stability than pure PEDOT, and the weight percentage of Th-GO could affect the doping level, amount of undesired conjugated segments, and porous structure of composites. Electrochemical analysis suggested that the highest specific capacitance of 320 F g-1 at a current density of 1 A g-1 with good cycling stability (capacitance retention of 80 % at 1 A g-1 after 1000 cycles) was achieved for the composite prepared from 50 wt% Th-GO content in reaction medium.

Chemical characterization and extractives composition of heartwood and sapwood from Quercus faginea.

PubMed

Miranda, Isabel; Sousa, Vicelina; Ferreira, Joana; Pereira, Helena

2017-01-01

Heartwood and sapwood of Quercus faginea were evaluated in relation to summative chemical composition and non-polar and polar extracts composition, including an assessment of antioxidant properties (DPPH and FRAP). Twenty trees from two sites in Portugal were analysed. Heartwood had approximately two times more solvent extractible compounds than sapwood (on average 19.0% and 9.5%). The lipophilic extractible compounds were below 1%, and most of them were polar e.g. ethanol-soluble compounds corresponded to 65% of total extractives in heartwood and 43% in sapwood. Lignin content was similar in sapwood and heartwood (28.1% and 28.6% of extractive-free wood respectively) as well as the sugar composition. Site did not influence the chemical composition. The lipophilic extractible compounds from both sapwood and heartwood included mainly saturated fatty acids (23.0% and 36.9% respectively) and aromatic compounds were also abundant in sapwood (22.9%). The ethanol-water extractibles had a high content of phenolic substances (558.0 and 319.4 mg GAE/g extract, respectively of heartwood and sapwood). The polyphenolic composition was similar in heartwood and sapwood with higher content of ellagitannins (168.9 and 153.5 mg tannic acid/g of extract in sapwood and heartwood respectively) and very low content of condensed tannins. The antioxidant activity was very high with IC50 of 2.6 μg/ml and 3.3 μg/ml for sapwood and heartwood respectively, as compared to standard antioxidants (IC50 of 3.8 μg/ml for Trolox). The ferric reducing ability was 2.8 and 2.0 mMol Trolox equivalents/g extract of heartwood and sapwood respectively. The variability between trees was low and no differences between the two sites were found. Q. faginea showed a very good potential for cooperage and other applications for which a source of compounds with antioxidant properties is desirable.

Bonding Effectiveness of Luting Composites to Different CAD/CAM Materials.

PubMed

Peumans, Marleen; Valjakova, Emilija Bajraktarova; De Munck, Jan; Mishevska, Cece Bajraktarova; Van Meerbeek, Bart

To evaluate the influence of different surface treatments of six novel CAD/CAM materials on the bonding effectiveness of two luting composites. Six different CAD/CAM materials were tested: four ceramics - Vita Mark II; IPS Empress CAD and IPS e.max CAD; Celtra Duo - one hybrid ceramic, Vita Enamic, and one composite CAD/CAM block, Lava Ultimate. A total of 60 blocks (10 per material) received various mechanical surface treatments: 1. 600-grit SiC paper; 2. sandblasting with 30-μm Al2O3; 3. tribochemical silica coating (CoJet). Subsequent chemical surface treatments involved either no further treatment (control), HF acid etching (HF), silanization (S, or HF acid etching followed by silanization (HF+S). Two specimens with the same surface treatment were bonded together using two dual-curing luting composites: Clearfil Esthetic Cement (self-etching) or Panavia SA Cement (self-adhesive). After 1 week of water storage, the microtensile bond strength of the sectioned microspecimens was measured and the failure mode was evaluated. The bonding performance of the six CAD/CAM materials was significantly influenced by surface treatment (linear mixed models, p < 0.05). The luting cement had a significant influence on bond strength for Celtra Duo and Lava Ultimate (linear mixed models, p < 0.05). Mechanical surface treatment significantly influenced the bond strength for Celtra Duo (p = 0.0117), IPS e.max CAD (p = 0.0115), and Lava Ultimate (p < 0.0001). Different chemical surface treatments resulted in the highest bond strengths for the six CAD/CAM materials: Vita Mark II and IPS Empress CAD: S, HF+S; Celtra Duo: HF, HF+S; IPS e.max CAD: HF+S; Vita Enamic: HF+S, S. For Lava Ultimate, the highest bond strengths were obtained with HF, S, HF+S. Failure analysis showed a relation between bond strength and failure type: more mixed failures were observed with higher bond strengths. Mainly adhesive failures were noticed if no further surface treatment was done. The percentage of

Characterization of composite materials based on cement-ceramic powder blended binder

NASA Astrophysics Data System (ADS)

Kulovaná, Tereza; Pavlík, Zbyšek

2016-06-01

Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO2 emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzed by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.

Thermal and Chemical Characterization of Non-Metallic Materials Using Coupled Thermogravimetric Analysis and Infrared Spectroscopy

NASA Technical Reports Server (NTRS)

Huff, Timothy L.

2002-01-01

Thermogravimetric analysis (TGA) is widely employed in the thermal characterization of non-metallic materials, yielding valuable information on decomposition characteristics of a sample over a wide temperature range. However, a potential wealth of chemical information is lost during the process, with the evolving gases generated during thermal decomposition escaping through the exhaust line. Fourier Transform-Infrared spectroscopy (FT-IR) is a powerful analytical technique for determining many chemical constituents while in any material state, in this application, the gas phase. By linking these two techniques, evolving gases generated during the TGA process are directed into an appropriately equipped infrared spectrometer for chemical speciation. Consequently, both thermal decomposition and chemical characterization of a material may be obtained in a single sample run. In practice, a heated transfer line is employed to connect the two instruments while a purge gas stream directs the evolving gases into the FT-IR. The purge gas can be either high purity air or an inert gas such as nitrogen to allow oxidative and pyrolytic processes to be examined, respectively. The FT-IR data is collected realtime, allowing continuous monitoring of chemical compositional changes over the course of thermal decomposition. Using this coupled technique, an array of diverse materials has been examined, including composites, plastics, rubber, fiberglass epoxy resins, polycarbonates, silicones, lubricants and fluorocarbon materials. The benefit of combining these two methodologies is of particular importance in the aerospace community, where newly developing materials have little available data with which to refer. By providing both thermal and chemical data simultaneously, a more definitive and comprehensive characterization of the material is possible. Additionally, this procedure has been found to be a viable screening technique for certain materials, with the generated data useful in

Thermal and Chemical Characterization of Non-metallic Materials Using Coupled Thermogravimetric Analysis and Infrared Spectroscopy

NASA Technical Reports Server (NTRS)

Huff, Timothy L.; Griffin, Dennis E. (Technical Monitor)

2001-01-01

Thermogravimetric analysis (TGA) is widely employed in the thermal characterization of non-metallic materials, yielding valuable information on decomposition characteristics of a sample over a wide temperature range. However, a potential wealth of chemical information is lost during the process, with the evolving gases generated during thermal decomposition escaping through the exhaust line. Fourier Transform-Infrared spectroscopy (FT-IR) is a powerful analytical technique for determining many chemical constituents while in any material state, in this application, the gas phase. By linking these two techniques, evolving gases generated during the TGA process are directed into an appropriately equipped infrared spectrometer for chemical speciation. Consequently, both thermal decomposition and chemical characterization of a material may be obtained in a single sample run. In practice, a heated transfer line is employed to connect the two instruments while a purge gas stream directs the evolving gases into the FT-IR, The purge gas can be either high purity air or an inert gas such as nitrogen to allow oxidative and pyrolytic processes to be examined, respectively. The FT-IR data is collected real-time, allowing continuous monitoring of chemical compositional changes over the course of thermal decomposition. Using this coupled technique, an array of diverse materials has been examined, including composites, plastics, rubber, fiberglass epoxy resins, polycarbonates, silicones, lubricants and fluorocarbon materials. The benefit of combining these two methodologies is of particular importance in the aerospace community, where newly developing materials have little available data with which to refer. By providing both thermal and chemical data simultaneously, a more definitive and comprehensive characterization of the material is possible. Additionally, this procedure has been found to be a viable screening technique for certain materials, with the generated data useful in

Ultra-low temperature curable nano-silver conductive adhesive for piezoelectric composite material

NASA Astrophysics Data System (ADS)

Yan, Chao; Liao, Qingwei; Zhou, Xingli; Wang, Likun; Zhong, Chao; Zhang, Di

2018-01-01

Limited by the low thermal resistance of composite material, ultra-low temperature curable conductive silver adhesive with curing temperature less than 100 °C needed urgently for the surface conduction treatment of piezoelectric composite material. An ultra-low temperature curable nano-silver conductive adhesive with high adhesion strength for the applications of piezoelectric composite material was investigated. The crystal structure of cured adhesive, SEM/EDS analysis, thermal analysis, adhesive properties and conductive properties of different content of nano-silver filler or micron-silver doping samples were studied. The results show that with 60 wt.% nano-silver filler the ultra-low temperature curable conductive silver adhesive had the relatively good conductivity as volume resistivity of 2.37 × 10-4 Ω cm, and good adhesion strength of 5.13 MPa. Minor micron-doping (below 15 wt.%) could improve conductivity, but would decrease other properties. The ultra-low temperature curable nano-silver conductive adhesive could successfully applied to piezoelectric composite material.

Synthesis and Engineering Materials Properties of Fluid Phase Chemical Hydrogen Storage Materials for Automotive Applications

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

Choi, Young Joon; Westman, Matthew P.; Karkamkar, Abhijeet J.

Among candidates for chemical hydrogen storage in PEM fuel cell automotive applications, ammonia borane (AB, NH3BH3) is considered to be one of the most promising materials due to its high practical hydrogen content of 14-16 wt%. This material is selected as a surrogate chemical for a hydrogen storage system. For easier transition to the existing infrastructure, a fluid phase hydrogen storage material is very attractive and thus, we investigated the engineering materials properties of AB in liquid carriers for a chemical hydrogen storage slurry system. Slurries composed of AB and high temperature liquids were prepared by mechanical milling and sonicationmore » in order to obtain stable and fluidic properties. Volumetric gas burette system was adopted to observe the kinetics of the H2 release reactions of the AB slurry and neat AB. Viscometry and microscopy were employed to further characterize slurries engineering properties. Using a tip-sonication method we have produced AB/silicone fluid slurries at solid loadings up to 40wt% (6.5wt% H2) with viscosities less than 500cP at 25°C.« less

Assessment of chemical and material contamination in waste wood fuels--A case study ranging over nine years.

PubMed

Edo, Mar; Björn, Erik; Persson, Per-Erik; Jansson, Stina

2016-03-01

The increased demand for waste wood (WW) as fuel in Swedish co-combustion facilities during the last years has increased the import of this material. Each country has different laws governing the use of chemicals and therefore the composition of the fuel will likely change when combining WW from different origins. To cope with this, enhanced knowledge is needed on WW composition and the performance of pre-treatment techniques for reduction of its contaminants. In this study, the chemical and physical characteristics of 500 WW samples collected at a co-combustion facility in Sweden between 2004 and 2013 were investigated to determine the variation of contaminant content over time. Multivariate data analysis was used for the interpretation of the data. The concentrations of all the studied contaminants varied widely between sampling occasions, demonstrating the highly variable composition of WW fuels. The efficiency of sieving as a pre-treatment measure to reduce the levels of contaminants was not sufficient, revealing that sieving should be used in combination with other pre-treatment methods. The results from this case study provide knowledge on waste wood composition that may benefit its management. This knowledge can be applied for selection of the most suitable pre-treatments to obtain high quality sustainable WW fuels. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Nano-composite materials

DOEpatents

Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland

2010-05-25

Nano-composite materials are disclosed. An exemplary method of producing a nano-composite material may comprise co-sputtering a transition metal and a refractory metal in a reactive atmosphere. The method may also comprise co-depositing a transition metal and a refractory metal composite structure on a substrate. The method may further comprise thermally annealing the deposited transition metal and refractory metal composite structure in a reactive atmosphere.

Room-Temperature, Ambient-Pressure Chemical Synthesis of Amine-Functionalized Hierarchical Carbon-Sulfur Composites for Lithium-Sulfur Battery Cathodes.

PubMed

Chae, Changju; Kim, Jinmin; Kim, Ju Young; Ji, Seulgi; Lee, Sun Sook; Kang, Yongku; Choi, Youngmin; Suk, Jungdon; Jeong, Sunho

2018-02-07

Recently, the achievement of newly designed carbon-sulfur composite materials has attracted a tremendous amount of attention as high-performance cathode materials for lithium-sulfur batteries. To date, sulfur materials have been generally synthesized by a sublimation technique in sealed containers. This is a well-developed technique for the synthesizing of well-ordered sulfur materials, but it is limited when used to scale up synthetic procedures for practical applications. In this study, we suggest an easily scalable, room-temperature/ambient-pressure chemical pathway for the synthesis of highly functioning cathode materials using electrostatically assembled, amine-terminated carbon materials. It is demonstrated that stable cycling performance outcomes are achievable with a capacity of 730 mAhg -1 at a current density of 1 C with good cycling stability by a virtue of the characteristic chemical/physical properties (a high conductivity for efficient charge conduction and the presence of a number of amine groups that can interact with sulfur atoms during electrochemical reactions) of composite materials. The critical roles of conductive carbon moieties and amine functional groups inside composite materials are clarified with combinatorial analyses by X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy.

Titan's Interior Chemical Composition: A Thermochemical Assessment*

NASA Astrophysics Data System (ADS)

Howard, Michael; Zaug, J. M.; Khare, B. N.; McKay, C. P.

2007-10-01

We study the interior composition of Titan using thermal chemical equilibrium calculations that are valid to high pressures and temperatures. The equations of state are based on exponential-6 fluid theory and have been validated against experimental data up to a few Mbars in pressure and approximately 20000K in temperature. In addition to CHNO molecules, we account for multi-phases of carbon, water and a variety of metals such as Al and Fe, and their oxides. With these fluid equations of state, chemical equilibrium is calculated for a set of product species. As the temperature and pressure evolves for increasing depth in the interior, the chemical equilibrium shifts. We assume that Titan is initially composed of comet material, which we assume to be solar, except for hydrogen, which we take to be depleted by a factor 1/690. We find that a significant amount of nitrogen is in the form of n2, rather than nh3. Moreover, above 12 kbars, as is the interior pressure of Titan, a significant amount of the carbon is in the form of graphite, rather than co2 and ch4. We discuss the implications of these results for understanding the atmospheric and surface composition of Titan. • This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Attenuation of Neutron and Gamma Radiation by a Composite Material Based on Modified Titanium Hydride with a Varied Boron Content

NASA Astrophysics Data System (ADS)

Yastrebinskii, R. N.

2018-04-01

The investigations on estimating the attenuation of capture gamma radiation by a composite neutron-shielding material based on modified titanium hydride and Portland cement with a varied amount of boron carbide are performed. The results of calculations demonstrate that an introduction of boron into this material enables significantly decreasing the thermal neutron flux density and hence the levels of capture gamma radiation. In particular, after introducing 1- 5 wt.% boron carbide into the material, the thermal neutron flux density on a 10 cm-thick layer is reduced by 11 to 176 factors, and the capture gamma dose rate - from 4 to 9 times, respectively. The difference in the degree of reduction in these functionals is attributed to the presence of capture gamma radiation in the epithermal region of the neutron spectrum.

Soursop (Annona muricata) vinegar production and its chemical compositions

NASA Astrophysics Data System (ADS)

Ho, Chin Wai; Lazim, Azwan Mat; Fazry, Shazrul; Zaki, Umi Kalsum Hj Hussain; Lim, Seng Joe

2016-11-01

Vinegar is a liquid product that undergoes double fermentations, which are alcoholic and acetous fermentation. Sugar source was converted to ethanol in alcoholic fermentation, meanwhile ethanol was oxidised to acetic acid during acetous fermentation. Soursop (Annona muricata) was the starting material in this study, as it is easily available in Malaysia. Its highly aromatic, juicy and distinctive flavours enables the production of high quality vinegar. The objective of this research is to produce good quality soursop vinegar as an innovative method to preserve and utilise the soursop fruit in Malaysia and to determine its chemical compositions. It was found that the sugar content reduces over time, and it is inversely proportional to the ethanol concentration, due to the production of ethanol from sugar. Acetic acid was also found to increase with increasing fermentation time. pH showed no significant difference (p>0.05) in the reduction of sugar and the production of ethanol. However, significantly higher (p<0.05) production of acetic acid was observed at pH 5.0 and 5.5, compared to that at pH 4.5. There were no significant differences (p > 0.05) in Vitamin C contents in all soursop vinegar samples produced using different treatments.

Effect of packaging materials on the chemical composition and microbiological quality of edible mushroom (Pleurotus ostreatus) grown on cassava peels.

PubMed

Ajayi, Oluwakemi; Obadina, Adewale; Idowu, Micheal; Adegunwa, Mojisola; Kajihausa, Olatundun; Sanni, Lateef; Asagbra, Yemisi; Ashiru, Bolanle; Tomlins, Keith

2015-07-01

Edible fungi such as mushrooms are highly perishable and deteriorate few days after harvest due to its high moisture content and inability to maintain their physiological status. In this study, the effect of packaging materials on the nutritional composition of mushroom cultivated from cassava peels was investigated. Mushroom samples were dried at 50°C in a cabinet dryer for 8 h. The dried mushroom samples packaged in four different packaging materials; high density polyethylene (HDPE), polypropylene (PP), laminated aluminum foil (LAF), high density polyethylene under vacuum (HDPEV) were stored at freezing (0°C) temperatures for 12 weeks. Samples were collected at 2-week intervals and analyzed for proximate composition (carbohydrate, protein, fat, fiber, ash, moisture), mineral content (calcium, potassium), vitamin C content, and microbiological qualities (total aerobic count, Pseudomonal count, Coliform count, Staphylococcal count, Salmonella count) using the standard laboratory procedures. Carbohydrate, protein, fat content of dried mushrooms packaged in HDPE at freezing temperature ranged from 45.2% to 53.5%, 18.0% to 20.3%, and 3.2% to 4.3%, while mushrooms in polypropylene ranged from 45.2% to 53.5%, 18.5% to 20.3%, 2.6% to 4.3%. Carbohydrate, protein, fat of mushroom in LAF ranged from 47.8% to 53.5%, 17.3% to 20.3%, and 3.3% to 4.3%, respectively, while carbohydrate, protein, fat of mushroom in HDPEV ranged from 51.1% to 53.5%, 19.5% to 20.3%, and 3.5% to 4.3%. Microbiological analysis showed that total aerobic count, Pseudomonal count, and Staphyloccocal count of dried mushroom ranged from 2.3 to 3.8 log cfu/g, 0.6 to 1.1 log cfu/g, and 0.4 to 0.5 log cfu/g, respectively. In conclusion, dried mushroom in HDPE packaged under vacuum at freezing temperature retained the nutritional constituents than those packaged with other packaging materials.

Effect of packaging materials on the chemical composition and microbiological quality of edible mushroom (Pleurotus ostreatus) grown on cassava peels

PubMed Central

Ajayi, Oluwakemi; Obadina, Adewale; Idowu, Micheal; Adegunwa, Mojisola; Kajihausa, Olatundun; Sanni, Lateef; Asagbra, Yemisi; Ashiru, Bolanle; Tomlins, Keith

2015-01-01

Edible fungi such as mushrooms are highly perishable and deteriorate few days after harvest due to its high moisture content and inability to maintain their physiological status. In this study, the effect of packaging materials on the nutritional composition of mushroom cultivated from cassava peels was investigated. Mushroom samples were dried at 50°C in a cabinet dryer for 8 h. The dried mushroom samples packaged in four different packaging materials; high density polyethylene (HDPE), polypropylene (PP), laminated aluminum foil (LAF), high density polyethylene under vacuum (HDPEV) were stored at freezing (0°C) temperatures for 12 weeks. Samples were collected at 2-week intervals and analyzed for proximate composition (carbohydrate, protein, fat, fiber, ash, moisture), mineral content (calcium, potassium), vitamin C content, and microbiological qualities (total aerobic count, Pseudomonal count, Coliform count, Staphylococcal count, Salmonella count) using the standard laboratory procedures. Carbohydrate, protein, fat content of dried mushrooms packaged in HDPE at freezing temperature ranged from 45.2% to 53.5%, 18.0% to 20.3%, and 3.2% to 4.3%, while mushrooms in polypropylene ranged from 45.2% to 53.5%, 18.5% to 20.3%, 2.6% to 4.3%. Carbohydrate, protein, fat of mushroom in LAF ranged from 47.8% to 53.5%, 17.3% to 20.3%, and 3.3% to 4.3%, respectively, while carbohydrate, protein, fat of mushroom in HDPEV ranged from 51.1% to 53.5%, 19.5% to 20.3%, and 3.5% to 4.3%. Microbiological analysis showed that total aerobic count, Pseudomonal count, and Staphyloccocal count of dried mushroom ranged from 2.3 to 3.8 log cfu/g, 0.6 to 1.1 log cfu/g, and 0.4 to 0.5 log cfu/g, respectively. In conclusion, dried mushroom in HDPE packaged under vacuum at freezing temperature retained the nutritional constituents than those packaged with other packaging materials. PMID:26288720

Influence of Chemical Composition and Heat Treatment Condition on Impact Toughness of 15Cr Ferritic Creep Resistant Steel

NASA Astrophysics Data System (ADS)

Toda, Yoshiaki; Tohyama, Hideaki; Kushima, Hideaki; Kimura, Kazuhiro; Abe, Fujio

Influences of chemical compositions, heat treatment and microstructure on impact toughness of 15Cr ferritic steel have been investigated. Charpy impact values of the furnace cooled steels were lower than 15J/cm2 at room temperature independent of chemical compositions. Drastic improvement in impact toughness has been attained by controlling the carbon and nitrogen contents, by the addition of nickel and by the increase in cooling rate after annealing. However, the effect of nickel on impact toughness strongly depends on carbon and nitrogen contents. Improvement in impact toughness of the 15Cr ferritic steel has not been explained by individual microstructural factors of grain size, distribution of precipitates, volume fraction of martensitic phase. It has been supposed that the increase in Charpy impact toughness of the 15Cr ferritic steel was attained by improvement in toughness of ferrite matrix itself.

Sea spray aerosol chemical composition: elemental and molecular mimics for laboratory studies of heterogeneous and multiphase reactions.

PubMed

Bertram, Timothy H; Cochran, Richard E; Grassian, Vicki H; Stone, Elizabeth A

2018-04-03

Sea spray aerosol particles (SSA), formed through wave breaking at the ocean surface, contribute to natural aerosol particle concentrations in remote regions of Earth's atmosphere, and alter the direct and indirect effects of aerosol particles on Earth's radiation budget. In addition, sea spray aerosol serves as suspended surface area that can catalyze trace gas reactions. It has been shown repeatedly that sea spray aerosol is heavily enriched in organic material compared to the surface ocean. The selective enrichment of organic material complicates the selection of representative molecular mimics of SSA for laboratory or computational studies. In this review, we first provide a short introduction to SSA formation processes and discuss chemical transformations of SSA that occur in polluted coastal regions and remote pristine air. We then focus on existing literature of the chemical composition of nascent SSA generated in controlled laboratory experiments and field investigations. We combine the evidence on the chemical properties of nascent SSA with literature measurements of SSA water uptake to assess SSA molecular composition and liquid water content. Efforts to speciate SSA organic material into molecular classes and specific molecules have led to the identification of saccharides, alkanes, free fatty acids, anionic surfactants, dicarboxylic acids, amino acids, proteinaceous matter, and other large macromolecules. However to date, less than 25% of the organic mass of nascent SSA has been quantified at a molecular level. As discussed here, quantitative measurements of size resolved elemental ratios, combined with determinations of water uptake properties, provides unique insight on the concentration of ions within SSA as a function of particle size, pointing to a controlling role for relative humidity and the hygroscopicity of SSA organic material at small particle diameters.

Influence of stage of lactation and year season on composition of mares' colostrum and milk and method and time of storage on vitamin C content in mares' milk.

PubMed

Markiewicz-Kęszycka, Maria; Czyżak-Runowska, Grażyna; Wójtowski, Jacek; Jóźwik, Artur; Pankiewicz, Radosław; Łęska, Bogusława; Krzyżewski, Józef; Strzałkowska, Nina; Marchewka, Joanna; Bagnicka, Emilia

2015-08-30

Mares' milk is becoming increasingly popular in Western Europe. This study was thus aimed at investigating the impact of stage of lactation and season on chemical composition, somatic cell count and some physicochemical parameters of mares' colostrum and milk, and at developing a method for the determination of vitamin C (ascorbic acid) in mares' milk and to determine its content in fresh and stored milk. The analysis conducted showed an effect of the stage of lactation on contents of selected chemical components and physicochemical parameters of mares' milk. In successive lactation periods levels of fat, cholesterol, energy value, citric acid and titratable acidity decreased, whereas levels of lactose and vitamin C, as well as the freezing point, increased. Analysis showed that milk produced in autumn (September, October, November) had a higher freezing point and lower concentrations of total solids, protein, fat, cholesterol, citric acid and energy value in comparison to milk produced in summer (June, July, August). Mares' milk was characterised by low somatic cell count throughout lactation. In terms of vitamin C stability the most advantageous method of milk storage was 6-month storage of lyophilised milk. In general, the results confirmed that mares' milk is a raw material with a unique chemical composition different from that produced by other farm animals. © 2014 Society of Chemical Industry.

Characterisation of chemical composition and energy content of green waste and municipal solid waste from Greater Brisbane, Australia.

PubMed

Hla, San Shwe; Roberts, Daniel

2015-07-01

The development and deployment of thermochemical waste-to-energy systems requires an understanding of the fundamental characteristics of waste streams. Despite Australia's growing interest in gasification of waste streams, no data are available on their thermochemical properties. This work presents, for the first time, a characterisation of green waste and municipal solid waste in terms of chemistry and energy content. The study took place in Brisbane, the capital city of Queensland. The municipal solid waste was hand-sorted and classified into ten groups, including non-combustibles. The chemical properties of the combustible portion of municipal solid waste were measured directly and compared with calculations made based on their weight ratios in the overall municipal solid waste. The results obtained from both methods were in good agreement. The moisture content of green waste ranged from 29% to 46%. This variability - and the tendency for soil material to contaminate the samples - was the main contributor to the variation of samples' energy content, which ranged between 7.8 and 10.7MJ/kg. The total moisture content of food wastes and garden wastes was as high as 70% and 60%, respectively, while the total moisture content of non-packaging plastics was as low as 2.2%. The overall energy content (lower heating value on a wet basis, LHVwb) of the municipal solid waste was 7.9MJ/kg, which is well above the World Bank-recommended value for utilisation in thermochemical conversion processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Study on spectroscopic characterization and property of PES/ micro-nano cellulose composite membrane material].

PubMed

Tang, Huan-Wei; Zhang, Li-Ping; Li, Shuai; Zhao, Guang-Jie; Qin, Zhu; Sun, Su-Qin

2010-03-01

In the present paper, the functional groups of PES/micro-nano cellulose composite membrane materials were characterized by Fourier transform infrared spectroscopy (FTIR). Also, changes in crystallinity in composite membrane materials were analyzed using X-ray diffraction (XRD). The effects of micro-nano cellulose content on hydrophilic property of composite membrane material were studied by measuring hydrophilic angle. The images of support layer structure of pure PES membrane material and composite membrane material were showed with scanning electron microscope (SEM). These results indicated that in the infrared spectrogram, the composite membrane material had characteristic peaks of both PES and micro-nano cellulose without appearance of other new characteristics peaks. It revealed that there were no new functional groups in the composite membrane material, and the level of molecular compatibility was achieved, which was based on the existence of inter-molecular hydrogen bond association between PES and micro-nano cellulose. Due to the existence of micro-nano cellulose, the crystallinity of composite membrane material was increased from 37.7% to 47.9%. The more the increase in micro-nano cellulose mass fraction, the better the van de Waal force and hydrogen bond force between composite membrane material and water were enhanced. The hydrophilic angle of composite membrane material was decreased from 55.8 degrees to 45.8 degrees and the surface energy was raised from 113.7 to 123.5 mN x m(-2). Consequently, the hydrophilic property of composite membrane material was improved. The number of pores in the support layer of composite membrane material was lager than that of pure PES membrane. Apparently, pores were more uniformly distributed.

Dynamics of shearing force and its correlations with chemical compositions and in vitro dry matter digestibility of stylo (Stylosanthes guianensis) stem.

PubMed

Zi, Xuejuan; Li, Mao; Zhou, Hanlin; Tang, Jun; Cai, Yimin

2017-12-01

The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo. The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

Natural Kenaf Fiber Reinforced Composites as Engineered Structural Materials

NASA Astrophysics Data System (ADS)

Dittenber, David B.

The objective of this work was to provide a comprehensive evaluation of natural fiber reinforced polymer (NFRP)'s ability to act as a structural material. As a chemical treatment, aligned kenaf fibers were treated with sodium hydroxide (alkalization) in different concentrations and durations and then manufactured into kenaf fiber / vinyl ester composite plates. Single fiber tensile properties and composite flexural properties, both in dry and saturated environments, were assessed. Based on ASTM standard testing, a comparison of flexural, tensile, compressive, and shear mechanical properties was also made between an untreated kenaf fiber reinforced composite, a chemically treated kenaf fiber reinforced composite, a glass fiber reinforced composite, and oriented strand board (OSB). The mechanical properties were evaluated for dry samples, samples immersed in water for 50 hours, and samples immersed in water until saturation (~2700 hours). Since NFRPs are more vulnerable to environmental effects than synthetic fiber composites, a series of weathering and environmental tests were conducted on the kenaf fiber composites. The environmental conditions studied include real-time outdoor weathering, elevated temperatures, immersion in different pH solutions, and UV exposure. In all of these tests, degradation was found to be more pronounced in the NFRPs than in the glass FRPs; however, in nearly every case the degradation was less than 50% of the flexural strength or stiffness. Using a method of overlapping and meshing discontinuous fiber ends, large mats of fiber bundles were manufactured into composite facesheets for structural insulated panels (SIPs). The polyisocyanurate foam cores proved to be poorly matched to the strength and stiffness of the NFRP facesheets, leading to premature core shear or delamination failures in both flexure and compressive testing. The NFRPs were found to match well with the theoretical stiffness prediction methods of classical lamination

A comparison of chemical compositions of reported altered oceanic crusts and global MORB data set: implication for isotopic heterogeneity of recycled materials

NASA Astrophysics Data System (ADS)

Shimoda, G.; Kogiso, T.

2017-12-01

Chemical composition of altered oceanic crust is one of important constraints to delineate chemical heterogeneity of the mantle. Accordingly, many researchers have been studied to determine bulk chemical composition of altered oceanic crust mainly based on chemical compositions of old oceanic crusts at Site 801 and Site 417/418, and young crust at Site 504 (e.g., Staudigel et al., 1996; Bach et al. 2003; Kuo et al., 2016). Their careful estimation provided reliable bulk chemical compositions of these Sites and revealed common geochemical feature of alteration. To assess effect of recycling of altered oceanic crust on chemical evolution of the mantle, it might be meaningful to discuss whether the reported chemical compositions of altered oceanic crusts can represent chemical composition of globally subducted oceanic crusts. Reported chemical compositions of fresh glass or less altered samples from Site 801, 417/418 and 504 were highly depleted compared to that of global MORB reported by Gale et al. (2013), suggesting that there might be sampling bias. Hence, it could be important to consider chemical difference between oceanic crusts of these three Sites and global MORB to discuss effect of recycling of oceanic crust on isotopic heterogeneity of the mantle. It has been suggested that one of controlling factors of chemical variation of oceanic crust is crustal spreading rate because different degree of partial melting affects chemical composition of magmas produced at a mid-ocean ridge. Crustal spreading rate could also affect intensity of alteration. Namely, oceanic crusts produced at slow-spreading ridges may prone to be altered due to existence of larger displacement faults compared to fast spreading ridges which have relatively smooth topography. Thus, it might be significant to evaluate isotopic evolution of oceanic crusts those were produced at different spreading rates. In this presentation, we will provide a possible chemical variation of altered oceanic

IR spectroscopic study of the chemical composition of epiphytic lichens

NASA Astrophysics Data System (ADS)

Meysurova, A. F.; Khizhnyak, S. D.; Pakhomov, P. M.

2011-11-01

Changes in the chemical composition of lichens exposed to pollutants are investigated by means of FTIR spectroscopy. According to model experiments, alkyl nitrates, ammonium salts, amines, and sulfones develop in the lichen thallus through the action of ammonia and nitric and sulfuric acids. Spectroscopic data of modeling experiments enabled nitrogen- and sulfur-containing substances to be identified as the main air pollutants in the vicinity of a pig-breeding complex and information to be obtained on the content of the pollutants and their impact on the lichens.

Mechanical characterization of composite materials by optical techniques: A review

NASA Astrophysics Data System (ADS)

Bruno, Luigi

2018-05-01

The present review provides an overview of work published in recent years dealing with the mechanical characterization of composite materials performed by optical techniques. The paper emphasizes the strengths derived from the employment of full-field methods when the strain field of an anisotropic material must be evaluated. This is framed in contrast to the use of conventional measurement techniques, which provide single values of the measured quantities unable to offer thorough descriptions of deformation distribution. The review outlines the intensity and articulation of work in this research field to date and its ongoing importance not only in the academy, but also in industrial sectors where composite materials represent a strategic resource for development.

Chemical Differentiation of Osseous, Dental, and Non-skeletal Materials in Forensic Anthropology using Elemental Analysis.

PubMed

Zimmerman, Heather A; Meizel-Lambert, Cayli J; Schultz, John J; Sigman, Michael E

2015-03-01

Forensic anthropologists are generally able to identify skeletal materials (bone and tooth) using gross anatomical features; however, highly fragmented or taphonomically altered materials may be problematic to identify. Several chemical analysis techniques have been shown to be reliable laboratory methods that can be used to determine if questionable fragments are osseous, dental, or non-skeletal in nature. The purpose of this review is to provide a detailed background of chemical analysis techniques focusing on elemental compositions that have been assessed for use in differentiating osseous, dental, and non-skeletal materials. More recently, chemical analysis studies have also focused on using the elemental composition of osseous/dental materials to evaluate species and provide individual discrimination, but have generally been successful only in small, closed groups, limiting their use forensically. Despite significant advances incorporating a variety of instruments, including handheld devices, further research is necessary to address issues in standardization, error rates, and sample size/diversity. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Composite Structural Materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberly, S. E.

1984-01-01

The development and application of filamentary composite materials, is considered. Such interest is based on the possibility of using relatively brittle materials with high modulus, high strength, but low density in composites with good durability and high tolerance to damage. Fiber reinforced composite materials of this kind offer substantially improved performance and potentially lower costs for aerospace hardware. Much progress has been made since the initial developments in the mid 1960's. There were only limited applied to the primary structure of operational vehicles, mainly as aircrafts.

The chemical composition and mineralogy of meteorites measured with very high spatial resolution by a laser mass spectrometer for in situ planetary research

NASA Astrophysics Data System (ADS)

Brigitte Neuland, Maike; Mezger, Klaus; Tulej, Marek; Frey, Samira; Riedo, Andreas; Wurz, Peter; Wiesendanger, Reto

2017-04-01

The knowledge of the chemical composition of moons, comets, asteroids or other planetary bodies is of particular importance for the investigation of the origin and evolution of the Solar System. High resolution in situ studies on planetary surfaces can yield important information on surface heterogeneity, basic grain mineralogy and chemical composition of surface and subsurface. In turn, these data are the basis for our understanding of the physical and chemical processes which led to the formation and alteration of planetary material [1]. We investigated samples of Allende and Sayh al Uhaymir with a highly miniaturised laser mass spectrometer (LMS), which has been designed and built for in situ space research [2,3]. Both meteorite samples were investigated with a spatial resolution of about 10μm in lateral direction. The high sensitivity and high dynamic range of the LMS allow for quantitative measurements of the abundances of the rock-forming and minor and trace elements with high accuracy [4]. From the data, the modal mineralogy of micrometre-sized chondrules can be inferred [5], conclusions about the condensation sequence of the material are possible and the sensitivity for radiogenic elements allows for dating analyses of the investigated material. We measured the composition of various chondrules in Allende, offering valuable clues about the condensation sequence of the different components of the meteorite. We explicitly investigated the chemical composition and heterogeneity of the Allende matrix with an accuracy that cannot be reached by the mechanical analysis methods that were and are widely used in meteoritic research. We demonstrate the capabilities for dating analyses with the LMS. By applying the U-Th-dating method, the age of the SaU169 sample could be determined. Our analyses show that the LMS would be a suitable instrument for high-quality quantitative chemical composition measurements on the surface of a celestial body like a planet, moon or

Structure and characteristics of functional powder composite materials obtained by spark plasma sintering

NASA Astrophysics Data System (ADS)

Oglezneva, S. A.; Kachenyuk, M. N.; Kulmeteva, V. B.; Ogleznev, N. B.

2017-07-01

The article describes the results of spark plasma sintering of ceramic materials based on titanium carbide, titanium carbosilicide, ceramic composite materials based on zirconium oxide, strengthened by carbon nanostructures and composite materials of electrotechnical purpose based on copper with addition of carbon structures and titanium carbosilicide. The research shows that the spark plasma sintering can achieve relative density of the material up to 98%. The effect of sintering temperature on the phase composition, density and porosity of the final product has been studied. It was found that with addition of carbon nanostructures the relative density and hardness decrease, but the fracture strength of ZrO2 increases up to times 2. The relative erosion resistance of the electrodes made of composite copper-based powder materials, obtained by spark plasma sintering during electroerosion treatment of tool steel exceeds that parameter of pure copper up to times 15.

Study on influence of vibration behavior of composite material damage by holography

NASA Astrophysics Data System (ADS)

Guo, Linfeng; Zhao, Zhimin; Gao, Mingjuan; Zhuang, Xianzhong

2006-01-01

Composite material has been applied widely in aeronautics, astronautics and some other fields due to their high strength, light weight and antifatigue and etc. But in the application, composite material may be destroyed or damaged, which may have impact on its further applications. Therefore, study on the influence of behavior of composite material damage becomes a hot research. In this paper, the common composite material for aircraft is used as the test object, and a study is conducted to investigate the influence of vibration behavior of composite material damage. The authors adopt the method of light-carrier wave and time-average holography. Compared the interference fringes of composite materials before and after damage, the width of the interference fringes of hologram of the damaged composite material is narrower than that of the fringes before. It means that the off-plane displacement of each point on the test object is larger than before. Based on the elastic mechanics theory, the off-plane displacement is inverse to the bending stiffness, and the bending stiffness of the test object will decrease after it is damaged. In other words, the vibration property of the composite material changes after damages occur. The research results of the paper show that the results accord with the analysis of theory.

Chemical composition and ruminal nutrient degradability of fresh and ensiled amaranth forage.

PubMed

Seguin, Philippe; Mustafa, Arif F; Donnelly, Danielle J; Gélinas, Bruce

2013-12-01

Amaranth is a crop with potential as a source of forage for ruminants that has not been well characterized. A study was conducted to determine the impact of ensiling on the nutritional quality and ruminal degradability of forage from two amaranth cultivars adapted to North America (i.e. Plainsman and D136). In particular, quantification and some microscopic characterization of oxalate found in amaranth were performed as it is an antiquality compound of concern. There were limited interactions between cultivars and ensiling for most variables. Differences in chemical composition between amaranth cultivars were also limited. Ensiling reduced non-structural carbohydrate and true protein contents. The proportion of acid detergent protein was high in fresh and ensiled forages of both cultivars (average of 177 g kg(-1) crude protein). Total oxalate content averaged 30 and 25 g kg(-1) in fresh and ensiled forages respectively. Ensiling reduced soluble oxalate content. Crystals observed in amaranth were calcium oxalate druses found mostly in idioblast cells in leaf mesophyll and parenchyma of primary and secondary veins. In situ ruminal degradability data indicated that both fresh and ensiled amaranth are highly degradable in the rumen. This study confirms that amaranth is a suitable forage for ruminant animals. Its chemical composition is comparable, for most variables, to that of other commonly used forage species. © 2013 Society of Chemical Industry.

Impact of industrial source on the chemical composition of loblolly pine

Treesearch

Thomas L. Eberhardt

2012-01-01

The chemical compositions of loblolly pine (Pinus taeda L.) bark samples from two industrial sources were determined for whole bark as well as the inner and outer bark components. Differences in extractive contents of the whole bark samples were primarily attributed to the different debarking methods which afforded different proportions of inner and outer bark....

Chemical Dependency Content in CSWE Accredited BSW Programs: A Survey of Course Content and Implications for Further Curricula Development.

ERIC Educational Resources Information Center

Jarrett, Herbert H.; Howard, Mary C.

1993-01-01

Reports on responses from 61 accredited baccalaureate programs of social work surveyed concerning inclusion of courses and instructional materials on alcoholism/chemical dependency in curricula, use made of 12-step programs and recovering people, and whether spirituality aspects were addressed. Concludes that content on alcoholism and chemical…

Chemical composition of solar dried blood and the ruminal content and its effect on performance of Japanese quails.

PubMed

Mishra, Jyotiprabha; Abraham, Robinson J J; Rao, V Appa; Rajini, R Asha; Mishra, B P; Sarangi, N R

2015-01-01

The aim was to determine the chemical composition of solar dried blood and rumen content (DBRC) and further ascertain the concentration at which DBRC could be included in Japanese quail diets without any adverse effect on its performance. Feeding trial on the effect of DBRC on performance of Japanese quails was studied up to 5 weeks. 252 numbers of day old (Nandanam Type III breed) Japanese quails were purchased from Poultry Research Station, Madhavaram and divided into 7 batches (control+ six treatments) each consisting of 36 birds. The DBRC was included at 0%, 5%, 10%, 15%, 20%, 25% and 30% in diets as control, treatment-1 (T1), treatment-2 (T2), treatment-3 (T3), treatment-4 (T4), treatment-5 (T5) and treatment-6 (T6) respectively in a completely randomized design to replace soybean meal in Japanese quail feed. The birds were provided with ad-labidum feed and drinking water ad-libitum during the entire experimental period. The crude protein (CP), crude fiber (CF), ether extract (EE) and ash contents of DBRC were 35.87%, 17.40%, 3.6% and 12.6%, respectively. The amount of essential amino acids and non-essential amino acid content were found to be 12.98 and 4.87 (g/100 g of feed) respectively in DBRC feed. Result showed that all birds fed DBRC diets performed better than the control group. Mortality was unaffected by dietary treatments. There was a significant difference (p<0.01) observed in weight gain in treatment groups compared to the control. Up to 30% DBRC could be incorporated in the diets of Japanese quails without any adverse effects on its performance.

Chemical composition of groundwater/drinking water and oncological disease mortality in Slovak Republic.

PubMed

Rapant, S; Cvečková, V; Fajčíková, K; Dietzová, Z; Stehlíková, B

2017-02-01

This study deals with the analysis of relationship between chemical composition of the groundwater/drinking water and the data on mortality from oncological diseases (MOD) in the Slovak Republic. Primary data consist of the Slovak national database of groundwater analyses (20,339 chemical analyses, 34 chemical elements/compounds) and data on MOD (17 health indicators) collected for the 10-year period (1994-2003). The chemical and health data were unified in the same form and expressed as the mean values for each of 2883 municipalities within the Slovak Republic. Pearson and Spearman correlation as well as artificial neural network (ANN) methods were used for analysis of the relationship between chemical composition of groundwater/drinking water and MOD. The most significant chemical elements having influence on MOD were identified together with their limit values (limit and optimal contents). Based on the results of calculations, made through the neural networks, the following eight chemical elements/parameters in the groundwater were defined as the most significant for MOD: Ca + Mg (mmol l -1 ), Ca, Mg, TDS, Cl, HCO 3 , SO 4 and NO 3 . The results document the highest relationship between MOD and groundwater contents of Ca + Mg (mmol l -1 ), Ca and Mg. We observe increased MOD with low (deficit) contents of these three parameters of groundwater/drinking water. The following limit values were set for the most significant groundwater chemicals/parameters: Ca + Mg 1.73-5.85 mmol l -1 , Ca 60.5-196.8 mg l -1 and Mg 25.6-35.8 mg l -1 . At these concentration ranges, the mortality for oncological diseases in the Slovak Republic is at the lowest levels. These limit values are about twice higher in comparison with the current Slovak valid guideline values for the drinking water.

Effect of Chemical Composition on Susceptibility to Weld Solidification Cracking in Austenitic Weld Metal

NASA Astrophysics Data System (ADS)

Kadoi, Kota; Shinozaki, Kenji

2017-12-01

The influence of the chemical composition, especially the niobium content, chromium equivalent Creq, and nickel equivalent Nieq, on the weld solidification cracking susceptibility in the austenite single-phase region in the Schaeffler diagram was investigated. Specimens were fabricated using the hot-wire laser welding process with widely different compositions of Creq, Nieq, and niobium in the region. The distributions of the susceptibility, such as the crack length and brittle temperature range (BTR), in the Schaeffler diagram revealed a region with high susceptibility to solidification cracking. Addition of niobium enhanced the susceptibility and changed the distribution of the susceptibility in the diagram. The BTR distribution was in good agreement with the distribution of the temperature range of solidification (Δ T) calculated by solidification simulation based on Scheil model. Δ T increased with increasing content of alloying elements such as niobium. The distribution of Δ T was dependent on the type of alloying element owing to the change of the partitioning behavior. Thus, the solidification cracking susceptibility in the austenite single-phase region depends on whether the alloy contains elements. The distribution of the susceptibility in the region is controlled by the change in Δ T and the segregation behavior of niobium with the chemical composition.

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

1979-01-01

A multifaceted program is described in which aeronautical, mechanical, and materials engineers interact to develop composite aircraft structures. Topics covered include: (1) the design of an advanced composite elevator and a proposed spar and rib assembly; (2) optimizing fiber orientation in the vicinity of heavily loaded joints; (3) failure mechanisms and delamination; (4) the construction of an ultralight sailplane; (5) computer-aided design; finite element analysis programs, preprocessor development, and array preprocessor for SPAR; (6) advanced analysis methods for composite structures; (7) ultrasonic nondestructive testing; (8) physical properties of epoxy resins and composites; (9) fatigue in composite materials, and (10) transverse thermal expansion of carbon/epoxy composites.

Functionalization of Graphene Oxide and its Composite with Poly(3,4-ethylenedioxythiophene) as Electrode Material for Supercapacitors.

PubMed

Wang, Minchao; Jamal, Ruxangul; Wang, Yujie; Yang, Lei; Liu, Fangfang; Abdiryim, Tursun

2015-12-01

In this study, poly(3,4-ethylenedioxythiophene)/thiophene-grafted graphene oxide (PEDOT/Th-GO) composites from covalently linking of Th-GO with PEDOT chains were prepared via in situ chemical polymerization with different weight percentage of Th-GO ranging between 40 and 70 % in reaction medium. The resulting composite materials were characterized using a various analytical techniques. The structural analysis showed that the composites displayed a higher degree of conjugation and thermal stability than pure PEDOT, and the weight percentage of Th-GO could affect the doping level, amount of undesired conjugated segments, and porous structure of composites. Electrochemical analysis suggested that the highest specific capacitance of 320 F g(-1) at a current density of 1 A g(-1) with good cycling stability (capacitance retention of 80 % at 1 A g(-1) after 1000 cycles) was achieved for the composite prepared from 50 wt% Th-GO content in reaction medium.

Titan's Interior Chemical Composition: Possible Important Phase Transitions

NASA Astrophysics Data System (ADS)

Howard, Michael; Fried, L. E.; Khare, B. N.; McKay, C. P.

2008-09-01

We study the interior composition of Titan using thermal chemical equilibrium calculations that are valid to high pressures and temperatures. The equations of state are based on exponential-6 fluid theory and have been validated against experimental data up to a few Mbars in pressure and approximately 20000K in temperature. In addition to CHNO molecules, we account for multi-phases of carbon, water and a variety of metals such as Al and Fe, and their oxides. With these fluid equations of state, chemical equilibrium is calculated for a set of product species. As the temperature and pressure evolves for increasing depth in the interior, the chemical equilibrium shifts. We assume that Titan is initially composed of comet material, which we assume to be solar, except for hydrogen, which we take to be depleted by a factor 1/1000. We find that a significant amount of nitrogen is in the form of N2, rather than NH3. Moreover, above 12 kbars pressure, as is the interior pressure of Titan, a significant amount of the carbon is in the form of graphite, rather than CO2 and CH4. We discuss the implications of these results for understanding the atmospheric and surface composition of Titan. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Composite structural materials

NASA Technical Reports Server (NTRS)

Loewy, R.; Wiberley, S. E.

1986-01-01

Overall emphasis is on basic long-term research in the following categories: constituent materials, composite materials, generic structural elements, processing science technology; and maintaining long-term structural integrity. Research in basic composition, characteristics, and processing science of composite materials and their constituents is balanced against the mechanics, conceptual design, fabrication, and testing of generic structural elements typical of aerospace vehicles so as to encourage the discovery of unusual solutions to present and future problems. Detailed descriptions of the progress achieved in the various component parts of this comprehensive program are presented.

Micromechanics of Composite Materials Governed by Vector Constitutive Laws

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Aboudi, Jacob; Arnold, Steven M.

2017-01-01

The high-fidelity generalized method of cells micromechanics theory has been extended for the prediction of the effective property tensor and the corresponding local field distributions for composites whose constituents are governed by vector constitutive laws. As shown, the shear analogy, which can predict effective transverse properties, is not valid in the general three-dimensional case. Consequently, a general derivation is presented that is applicable to both continuously and discontinuously reinforced composites with arbitrary vector constitutive laws and periodic microstructures. Results are given for thermal and electric problems, effective properties and local field distributions, ordered and random microstructures, as well as complex geometries including woven composites. Comparisons of the theory's predictions are made to test data, numerical analysis, and classical expressions from the literature. Further, classical methods cannot provide the local field distributions in the composite, and it is demonstrated that, as the percolation threshold is approached, their predictions are increasingly unreliable. XXXX It has been observed that the bonding between the fibers and matrix in composite materials can be imperfect. In the context of thermal conductivity, such imperfect interfaces have been investigated in micromechanical models by Dunn and Taya (1993), Duan and Karihaloo (2007), Nan et al. (1997) and Hashin (2001). The present HFGMC micromechanical method, derived for perfectly bonded composite materials governed by vector constitutive laws, can be easily generalized to include the effects of weak bonding between the constituents. Such generalizations, in the context of the mechanical micromechanics problem, involve introduction of a traction-separation law at the fiber/matrix interface and have been presented by Aboudi (1987), Bednarcyk and Arnold (2002), Bednarcyk et al. (2004) and Aboudi et al. (2013) and will be addressed in the future.

Chemical compositions of primitive solar system particles

NASA Technical Reports Server (NTRS)

Sutton, Steve R.; Bajt, S.

1994-01-01

Chemical studies of micrometeorites are of fundamental importance primarily because atmospheric entry selection effects (such as destruction of friable objects) are less significant than those for conventional meteorites. As a result, particles that have experienced very little postaccretional processing have a significant chance of surviving the Earth encounter and subsequent collection. Thus, chemical analyses of these relatively unaltered micrometeorites may lead to a better understanding of the compositions of the most primitive materials in the solar system and thereby constrain the conditions (physical and chemical) that existed in the early solar nebula. Micrometeorites have been collected from the stratosphere, polar ices, and ocean sediments, but the stratospheric collection is the best source for the most unaltered material because they are small and are not heated to their melting points. Despite the fact that the stratospheric micrometeorites have masses in the nanogram range, a variety of microanalytical techniques have been applied to bulk chemical analyses with part-per-million sensitivity. In some cases, multi-disciplinary studies (e.g., chemistry and mineralogy) have been performed on individual particles. The first-order conclusion is that the chondrite-like particles are chemically similar to carbonaceous chondrites but in detail are distinct from members of the conventional meteorite collection. The purpose of this paper is to provide an overview of the results to date and identify important areas for further study.

Crystal Structure and Chemical Composition of a Presolar Silicate from the Queen Elizabeth Range 99177 Meteorite

NASA Technical Reports Server (NTRS)

Nguyen, A. N.; Keller, L. P.; Rahman, Z.; Messenger, S.

2013-01-01

Mineral characterization of presolar silicate grains, the most abundant stardust phase, has provided valuable information about the formation conditions in circumstellar environments and in super-nova (SN) outflows. Spectroscopic observations of dust around evolved stars suggest a majority of amor-phous, Mg-rich olivine grains, but crystalline silicates, most of which are pyroxene, have also been observed [1]. The chemical compositions of hundreds of presolar silicates have been determined by Auger spectroscopy and reveal high Fe contents and nonstoichiometric compositions intermediate to olivine and pyroxene [2-6]. The unexpectedly high Fe contents can partly be attributed to secondary alteration on the meteorite parent bodies, as some grains have Fe isotopic anomalies from their parent stellar source [7]. Only about 35 presolar silicates have been studied for their mineral structures and chemical compositions by transmission electron microscopy (TEM). These grains display a wide range of compositions and structures, including crystalline forsterite, crystalline pyroxene, nanocrystalline grains, and a majority of amorphous nonstoichiometric grains. Most of these grains were identified in the primitive Acfer 094 meteorite. Presolar silicates from this meteorite show a wide range of Fe-contents, suggestive of secondary processing on the meteorite parent body. The CR chondrite QUE 99177 has not suffered as much alteration [8] and displays the highest presolar silicate abundance to date among carbonaceous chondrites [3, 6]. However, no mineralogical studies of presolar silicates from this meteorite have been performed. Here we examine the mineralogy of a presolar silicate from QUE 99177.

Quantifying the chemical composition of soil organic carbon with solid-state 13C NMR

NASA Astrophysics Data System (ADS)

Baldock, J. A.; Sanderman, J.

2011-12-01

The vulnerability of soil organic carbon (SOC) to biological decomposition and mineralisation to CO2 is defined at least partially by its chemical composition. Highly aromatic charcoal-like SOC components are more stable to biological decomposition than other forms of carbon including cellulose. Solid-state 13C NMR has gained wide acceptance as a method capable of defining SOC chemical composition and mathematical fitting processes have been developed to estimate biochemical composition. Obtaining accurate estimates depends on an ability to quantitatively detect all carbon present in a sample. Often little attention has been paid to defining the proportion of organic carbon present in a soil that is observable in solid-state 13C NMR analyses of soil samples. However, if such data is to be used to inform carbon cycling studies, it is critical that quantitative assessments of SOC observability be undertaken. For example, it is now well established that a significant discrimination exists against the detection of the low proton content polyaromatic structures typical of charcoal using cross polarisation 13C NMR analyses. Such discrimination does not exist where direct polarisation analyses are completed. In this study, the chemical composition of SOC as defined by cross polarisation and direct polarisation13C NMR analyses will be compared for Australian soils collected from under a diverse range of agricultural managements and climatic conditions. Results indicate that where significant charcoal C contents exist, it is highly under-represented in the acquired CP spectra. For some soils, a discrimination against alkyl carbon was also evident. The ability to derive correction factors to compensate for such discriminations will be assessed and presented.

Grained composite materials prepared by combustion synthesis under mechanical pressure

DOEpatents

Dunmead, Stephen D.; Holt, Joseph B.; Kingman, Donald D.; Munir, Zuhair A.

1990-01-01

Dense, finely grained composite materials comprising one or more ceramic phase or phase and one or more metallic and/or intermetallic phase or phases are produced by combustion synthesis. Spherical ceramic grains are homogeneously dispersed within the matrix. Methods are provided, which include the step of applying mechanical pressure during or immediately after ignition, by which the microstructures in the resulting composites can be controllably selected.

Lipid content and composition of coffee brews prepared by different methods.

PubMed

Ratnayake, W M; Hollywood, R; O'Grady, E; Stavric, B

1993-04-01

The lipid content and composition of boiled, filtered, dripped, Turkish and espresso coffees prepared from roasted beans of Coffea arabica and Coffea robusta, and of coffees prepared from different brands of instant coffee were examined. The lipid content varied with the method of preparation. While coffee brews filtered through filter paper contained less than 7 mg lipids, those prepared by boiling without filtering and espresso coffee reached 60-160 mg lipids/150-ml cup. Coffee brew filtered through a metal screener contained 50 mg lipids/150-ml cup. Although the lipid content varied, the method of preparation of the brew and filtration had no important influence on the lipid composition. During paper filtration lipids remained mainly in spent coffee grounds, and the brew and filter paper retained only 0.4 and 9.4%, respectively, of the total lipids recovered. However, the lipids in the brew, filter paper and spent coffee grounds had the same profile, indicating that there was no preferential retention of a particular lipid component in filter paper. Triglycerides and diterpene alcohol esters were the major lipid classes in coffee brewed from ground coffee beans, and ranged from 86.6 to 92.9 and 6.5 to 12.5% of total lipids, respectively. For coffee brews made from instant coffee, the levels of these two lipid classes were 96.4-98.5 and 1.6-3.6%, respectively. The lipid contents of both regular and decaffeinated instant coffees varied slightly from one brand to the other, and ranged from 1.8 to 6.6 mg/150-ml cup.

Mumijo Traditional Medicine: Fossil Deposits from Antarctica (Chemical Composition and Beneficial Bioactivity)

PubMed Central

Aiello, Anna; Fattorusso, Ernesto; Menna, Marialuisa; Vitalone, Rocco; Schröder, Heinz C.; Müller, Werner E. G.

2011-01-01

Mumijo is a widely used traditional medicine, especially in Russia, Altai Mountains, Mongolia, Iran Kasachstan and in Kirgistan. Mumijo preparations have been successfully used for the prevention and treatment of infectious diseases; they display immune-stimulating and antiallergic activity as well. In the present study, we investigate the chemical composition and the biomedical potential of a Mumijo(-related) product collected from the Antarctica. The yellow material originates from the snow petrels, Pagodroma nivea. Extensive purification and chemical analysis revealed that the fossil samples are a mixture of glycerol derivatives. In vitro experiments showed that the Mumijo extract caused in cortical neurons a strong neuroprotective effect against the apoptosis-inducing amyloid peptide fragment β-fragment 25–35 (Aβ25–35). In addition, the fraction rich in glycerol ethers/wax esters displayed a significant growth-promoting activity in permanent neuronal PC12 cells. It is concluded that this new Mumijo preparation has distinct and marked neuroprotective activity, very likely due to the content of glycerol ether derivatives. PMID:18996940

Finite Element Modeling of the Thermographic Inspection for Composite Materials

NASA Technical Reports Server (NTRS)

Bucinell, Ronald B.

1996-01-01

The performance of composite materials is dependent on the constituent materials selected, material structural geometry, and the fabrication process. Flaws can form in composite materials as a result of the fabrication process, handling in the manufacturing environment, and exposure in the service environment to anomalous activity. Often these flaws show no indication on the surface of the material while having the potential of substantially degrading the integrity of the composite structure. For this reason it is important to have available inspection techniques that can reliably detect sub-surface defects such as inter-ply disbonds, inter-ply cracks, porosity, and density changes caused by variations in fiber volume content. Many non-destructive evaluation techniques (NDE) are capable of detecting sub-surface flaws in composite materials. These include shearography, video image correlation, ultrasonic, acoustic emissions, and X-ray. The difficulty with most of these techniques is that they are time consuming and often difficult to apply to full scale structures. An NDE technique that appears to have the capability to quickly and easily detect flaws in composite structure is thermography. This technique uses heat to detect flaws. Heat is applied to the surface of a structure with the use of a heat lamp or heat gun. A thermographic camera is then pointed at the surface and records the surface temperature as the composite structure cools. Flaws in the material will cause the thermal-mechanical material response to change. Thus, the surface over an area where a flaw is present will cool differently than regions where flaws do not exist. This paper discusses the effort made to thermo-mechanically model the thermography process. First the material properties and physical parameters used in the model will be explained. This will be followed by a detailed discussion of the finite element model used. Finally, the result of the model will be summarized along with

Antioxidant properties, physico-chemical characteristics and proximate composition of five wild fruits of Manipur, India.

PubMed

Sharma, Ph Baleshwor; Handique, Pratap Jyoti; Devi, Huidrom Sunitibala

2015-02-01

Antioxidant properties, physico-chemical characteristics and proximate composition of five wild fruits viz., Garcinia pedunculata, Garcinia xanthochymus, Docynia indica, Rhus semialata and Averrhoa carambola grown in Manipur, India were presented in the current study. The order of the antioxidant activity and reducing power of the fruit samples was found as R. semialata > D. indica > G. xanthochymus > A. carambola > G. pedunculata. Good correlation coefficient (R(2) > 0.99) was found among the three methods applied to determine antioxidant activity. Total phenolic content was positively correlated (R(2) = 0.960) with the antioxidant activity however, total flavonoid content was not positively correlated with the antioxidant activity. Physico-chemical and proximate composition of these fruits is documented for the first time.

Polymer-encapsulated metal nanoparticles: optical, structural, micro-analytical and hydrogenation studies of a composite material.

PubMed

Scalzullo, Stefania; Mondal, Kartick; Witcomb, Mike; Deshmukh, Amit; Scurrell, Mike; Mallick, Kaushik

2008-02-20

A single-step synthesis route is described for the preparation of a metal-polymer composite in which palladium acetate and meta-amino benzoic acid were used as the precursors for palladium nanoparticles and poly(meta-amino benzoic acid) (PABA). The palladium nanoparticles were found to be uniformly dispersed and highly stabilized throughout the macromolecule matrix. The resultant composite material was characterized by means of different techniques, such as IR and Raman spectroscopy, which provided information regarding the chemical structure of the polymer, whereas electron microscopy images yielded information regarding the morphology of the composite material and the distribution of the metal particles in the composite material. The composite material was used as a catalyst for the ethylene hydrogenation reaction and showed catalytic activity at higher temperatures. TEM studies confirmed the changed environment of the nanoparticles at these temperatures.

Chemical composition and nutritional quality of sea cucumbers.

PubMed

Wen, Jing; Hu, Chaoqun; Fan, Sigang

2010-11-01

The dried form of sea cucumbers has been a seafood and medicinal cure for Asians over many centuries. In this study the chemical composition and nutritional quality of eight common sea cucumbers (Stichopus herrmanni, Thelenota ananas, Thelenota anax, Holothuria fuscogilva, Holothuria fuscopunctata, Actinopyga mauritiana, Actinopyga caerulea and Bohadschia argus) were determined. All species except T. anax and A. caerulea had higher protein and lower fat levels. A. mauritiana and B. argus had less ash content. Glycine was the dominant amino acid found in all species, and content ranged from 126 to 216 mg g(-1) of crude protein. All species exhibited low lysine:arginine ratio and higher essential amino acid scores were obtained by threonine and phenylalanine + tyrosine. A. mauritiana had proportionally less saturated fatty acids (31.23%), and more monounsaturated fatty acids (45.64%) and polyunsaturated fatty acids (PUFA, 23.13%) than other species. Arachidonic acid (C20:4n-6) was the major PUFA in all species. T. ananas, A. mauritiana and A. caerulea contained more n-3 PUFA. The n-3/n-6 ratios of eight sea cucumbers species ranged from 0.25 to 0.61. Sea cucumbers are a seafood with high protein and low fat levels. The amino acid contents were similar but fatty acid profiles were different among species. The comparison showed that T. ananas, A. mauritiana and B. argus possessed higher nutritional values than other sea cucumber species. 2010 Society of Chemical Industry

Computing Equilibrium Chemical Compositions

NASA Technical Reports Server (NTRS)

Mcbride, Bonnie J.; Gordon, Sanford

1995-01-01

Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

Characterization of composite materials based on cement-ceramic powder blended binder

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

Kulovaná, Tereza; Pavlík, Zbyšek

Characterization of newly developed composite mortars with incorporated ceramic powder coming from precise brick cutting as partial Portland cement replacement up to 40 mass% is presented in the paper. Fine ceramic powder belongs to the pozzolanic materials. Utilization of pozzolanic materials is accompanied by lower request on energy needed for Portland clinker production which generally results in lower production costs of blended binder and lower CO{sub 2} emission. In this paper, the ceramic powder is used in cement based mortar composition in amount of 8, 16, 24, 32, and 40 mass% of cement. Chemical composition of ceramic powder is analyzedmore » by X-Ray Fluorescence and X-Ray Diffraction. The particle size distribution of ceramics is accessed on laser diffraction principle. For 28 days cured mortar samples, basic physical and mechanical properties are experimentally determined. The obtained results demonstrate that ceramic powder has potential to replace a part of Portland cement in composition of cement based composites and to reduce negative environmental impact of their production.« less

Wood-based composite materials : panel products, glued-laminated timber, structural composite lumber, and wood-nonwood composite materials

Treesearch

Nicole M. Stark; Zhiyong Cai; Charles Carll

2010-01-01

This chapter gives an overview of the general types and composition of wood-based composite products and the materials and processes used to manufacture them. It describes conventional wood-based composite panels and structural composite materials intended for general construction, interior use, or both. This chapter also describes wood–nonwood composites. Mechanical...

Effect of Moisture Content on Thermal Properties of Porous Building Materials

NASA Astrophysics Data System (ADS)

Kočí, Václav; Vejmelková, Eva; Čáchová, Monika; Koňáková, Dana; Keppert, Martin; Maděra, Jiří; Černý, Robert

2017-02-01

The thermal conductivity and specific heat capacity of characteristic types of porous building materials are determined in the whole range of moisture content from dry to fully water-saturated state. A transient pulse technique is used in the experiments, in order to avoid the influence of moisture transport on measured data. The investigated specimens include cement composites, ceramics, plasters, and thermal insulation boards. The effect of moisture-induced changes in thermal conductivity and specific heat capacity on the energy performance of selected building envelopes containing the studied materials is then analyzed using computational modeling of coupled heat and moisture transport. The results show an increased moisture content as a substantial negative factor affecting both thermal properties of materials and energy balance of envelopes, which underlines the necessity to use moisture-dependent thermal parameters of building materials in energy-related calculations.

Novel Repair Concept for Composite Materials by Repetitive Geometrical Interlock Elements

PubMed Central

Hufenbach, Werner; Adam, Frank; Heber, Thomas; Weckend, Nico; Bach, Friedrich-Wilhelm; Hassel, Thomas; Zaremba, David

2011-01-01

Material adapted repair technologies for fiber-reinforced polymers with thermosetting matrix systems are currently characterized by requiring major efforts for repair preparation and accomplishment in all industrial areas of application. In order to allow for a uniform distribution of material and geometrical parameters over the repair zone, a novel composite interlock repair concept is introduced, which is based on a repair zone with undercuts prepared by water-jet technology. The presented numerical and experimental sensitivity analyses make a contribution to the systematic development of the interlock repair technology with respect to material and geometrical factors of influence. The results show the ability of the novel concept for a reproducible and automatable composite repair. PMID:28824134

Seasonal changes in chemical and mineralogical composition of sewage sludge incineration residues and their potential for metallic elements and valuable components recovery

NASA Astrophysics Data System (ADS)

Kasina, Monika; Kowalski, Piotr R.; Michalik, Marek

2017-04-01

Increasing energy needs, the implementation of the circular economy principles and rising environmental awareness caused that waste management is becoming a major social and economic issue. The EU Member States have committed to a significant reduction in the amount of waste produced and landfilled and to use their inherent energy and raw materials potential. One of the most reasonable option to fulfil these commitments is waste incineration. The aim of the waste incineration is to reduce their volume and toxicity by disinfection and detoxification at high temperatures. Thermal process and reduction of volume allows the recovery of minerals and metallic elements from residues as well as the energy production (waste-to-energy strategy) during incineration. As a result of waste incineration a variety of solid residues (bottom ash, fly ash, air pollution control residues) and technological waste (gas waste, wastewater) are produced. The goal of this study is to characterize fly ash and air pollution control (APC) residues formed as a result of municipal sewage sludge incineration in terms of their chemical and mineral composition and their extractive potential. Residues were sampled quarterly to study their seasonal changes in composition. The fly ash was a Si-P-C-Fe-Al dominated material, whereas the APC residues composition was dominated by Na-rich soluble phases. The removal of soluble phase ( 98% of the material) from the APC residues by dissolution in deionised water caused significant mass reduction and concentration of non-soluble elements. The main mineral phases in fly ash were quartz, hematite, Fe-PO4, whitlockite and feldspar, while in APC thenardite, and in lower amount calcite, apatite and quartz were present. The chemical composition of fly ash was practically invariable in different seasons, but significant differences were observed in APC residues. The lowest concentrations of all elements and the highest TOC content were measured in the samples

Fiber Optic Sensors for Cure/Health Monitoring of Composite Materials

NASA Technical Reports Server (NTRS)

Wood, K. H.; Brown, T. L.; Wu, M. C.; Gause, C. B.

2004-01-01

The objective of the current program is to develop techniques for using optical fibers to monitor the cure of composite materials in real time during manufacture and to monitor the in-service structural health of composite structures. Single and multimode optical fibers containing Bragg gratings have been used to perform Near Infrared (NIR) spectroscopy on high refractive index resins and show promise as embedded sensors. In order for chemical spectroscopy to be possible, intimate contact must be achieved between the fiber core and the composite resin. This contact is often achieved by stripping the cladding off of a portion of the fiber, thus making it brittle and easily broken in the composite processing environment. To avoid weakening the fiber to this extent, high refractive index fibers have been fabricated that use a low refractive index acrylate coating which serves as the cladding. This is ideal, as the coating is easily solvent stripped and intimate contact with the glass core can be achieved. Real time resin and composite chemical spectra have been obtained, with possible multifunctional capability using Bragg gratings to assess physical properties such as strain, modulus and other parameters of interest.

Qualitative and quantitative studies of chemical composition of sandarac resin by GC-MS.

PubMed

Kononenko, I; de Viguerie, L; Rochut, S; Walter, Ph

2017-01-01

The chemical composition of sandarac resin was investigated qualitatively and quantitatively by gas chromatography-mass spectrometry (GC-MS). Six compounds with labdane and pimarane skeletons were identified in the resin. The obtained mass spectra were interpreted and the mass spectrometric behaviour of these diterpenoids under EI conditions was described. Quantitative analysis by the method of internal standard revealed that identified diterpenoids represent only 10-30% of the analysed sample. The sandarac resin from different suppliers was analysed (from Kremer, Okhra, Color Rare, La Marchande de Couleurs, L'Atelier Montessori, Hevea). The analysis of different lumps of resins showed that the chemical composition differs from one lump to another, varying mainly in the relative distributions of the components.

Utilization of composite materials by the US Army: A look ahead

NASA Technical Reports Server (NTRS)

Chait, Richard

1992-01-01

An overview of the use of composite materials in the Army is given. Important efforts to document design information, supporting research, and some national applications for composite materials are given. The use of Kevlar fiber in both vests and helmets for the soldier is outlined. The advantages of using fiberglass in the hull of the Bradley fighting ground vehicle is given. The full potential of composite materials is realized in the recently awarded LH Comanche RAH-66 program. The use of composites for application to rocket motor uses, wings, fins, and casings is under development. Because of the uncertain funding profile, it is more important than ever that technology planning provide the basis for effective prioritization and leveraging of the tech base efforts involving advanced materials.

Elemental Compositions of Comet 81P/Wild 2 Samples Collected by Stardust

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Bleuet, P.; Borg, J.; Bradley, J.; Brenker, F.; Brennan, S.; Bridges, J.; Brownlee, D. E.; Bullock, E.; Clark, B. C.;

Dual stimuli responsive self-reporting material for chemical reservoir coating

NASA Astrophysics Data System (ADS)

Lee, Tae Hee; Song, Young Kyu; Park, Sun Hee; Park, Young Il; Noh, Seung Man; Kim, Jin Chul

2018-03-01

In this study, we introduce a novel dual stimuli responsive self-reporting thiol-epoxy thermoset (DSRTET) coatings which can detect both crack occurrence and pH variation. For crack detection, microcapsule containing tetraphenylethylene (TPE) which exhibits aggregation induced emission (AIE) effect was prepared via multi-step emulsion polymerization and dispersed in DSRTET coatings. For pH variation detection, commercial thymol blue as a pH indicator was added into the polymer matrix. The effect of microcapsule contents in DSRTET on their curing behavior, material properties, and crack sensitivity was characterized using an oscillatory rheology, rigid body pendulum test (RPT), nano-indentation test (NST), universal test machine (UTM) and scratch tester. It was revealed that crack sensitivity of DSRTET coatings was greatly influenced by material properties as well as microcapsule content. The color transition of DSRTET coatings in response to acid or base solution were quantitatively investigated using a multi-angle spectrophotometer after simple acid and base solution drop tests. The color of DSRTET coatings changed from a pale green to red for acidic solution and to blue for basic solution. Finally, The DSRTET used in this study was applied to laboratory scale chemical reservoirs in order to verify the potential as a dual stimuli response self-reporting coating which can detect both crack in coating material and chemical spill caused by the leakage or breakage of the reservoir part.

Control of polymerization shrinkage and stress in nanogel-modified monomer and composite materials.

PubMed

Moraes, Rafael R; Garcia, Jeffrey W; Barros, Matthew D; Lewis, Steven H; Pfeifer, Carmem S; Liu, JianCheng; Stansbury, Jeffrey W

2011-06-01

This study demonstrates the effects of nano-scale prepolymer particles as additives to model dental monomer and composite formulations. Discrete nanogel particles were prepared by solution photopolymerization of isobornyl methacrylate and urethane dimethacrylate in the presence of a chain transfer agent, which also provided a means to attach reactive groups to the prepolymer. Nanogel was added to triethylene glycol dimethacrylate (TEGDMA) in increments between 5 and 40 wt% with resin viscosity, reaction kinetics, shrinkage, mechanical properties, stress and optical properties evaluated. Maximum loading of barium glass filler was determined as a function of nanogel content and composites with varied nanogel content but uniform filler loading were compared in terms of consistency, conversion, shrinkage and mechanical properties. High conversion, high molecular weight internally crosslinked and cyclized nanogel prepolymer was efficiently prepared and redispersed into TEGDMA with an exponential rise in viscosity accompanying nanogel content. Nanogel addition at any level produced no deleterious effects on reaction kinetics, conversion or mechanical properties, as long as reactive nanogels were used. A reduction in polymerization shrinkage and stress was achieved in proportion to nanogel content. Even at high nanogel concentrations, the maximum loading of glass filler was only marginally reduced relative to the control and high strength composite materials with low shrinkage were obtained. The use of reactive nanogels offers a versatile platform from which resin and composite handling properties can be adjusted while the polymerization shrinkage and stress development that challenge the adhesive bonding of dental restoratives are controllably reduced. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Characteristics of biomass ashes from different materials and their ameliorative effects on acid soils.

PubMed

Shi, Renyong; Li, Jiuyu; Jiang, Jun; Mehmood, Khalid; Liu, Yuan; Xu, Renkou; Qian, Wei

2017-05-01

The chemical characteristics, element contents, mineral compositions, and the ameliorative effects on acid soils of five biomass ashes from different materials were analyzed. The chemical properties of the ashes varied depending on the source biomass material. An increase in the concrete shuttering contents in the biomass materials led to higher alkalinity, and higher Ca and Mg levels in biomass ashes, which made them particularly good at ameliorating effects on soil acidity. However, heavy metal contents, such as Cr, Cu, and Zn in the ashes, were relatively high. The incorporation of all ashes increased soil pH, exchangeable base cations, and available phosphorus, but decreased soil exchangeable acidity. The application of the ashes from biomass materials with a high concrete shuttering content increased the soil available heavy metal contents. Therefore, the biomass ashes from wood and crop residues with low concrete contents were the better acid soil amendments. Copyright © 2016. Published by Elsevier B.V.

Determination of chemical purity and isotopic composition of natural and carbon-13-labeled arsenobetaine bromide standards by quantitative(1)H-NMR.

PubMed

Le, Phuong-Mai; Ding, Jianfu; Leek, Donald M; Mester, Zoltan; Robertson, Gilles; Windust, Anthony; Meija, Juris

2016-10-01

In this study, we report the characterization of three arsenobetaine-certified reference materials by quantitative NMR. We have synthesized an arsenobetaine bromide high-purity standard of natural isotopic composition (ABET-1) and two carbon-13-labeled isotopic standards (BBET-1 and CBET-1). Assignments of the chemical purity and isotopic composition are not trivial in the case of arsenobetaine, and in this study we utilized quantitative(1)H-NMR techniques for the determination of the mass fractions (chemical purity). The isotopic purity of all three standards was also assessed by NMR from the carbon-13 satellite signals. The standards are non-hygroscopic, high-purity (ca. 0.99 g/g), and the carbon-13 enrichment for both isotopic standards is x((13)C)≈0.99. These standards are designed for use as primary calibrators for mass spectrometric determination of arsenobetaine in environmental samples.

Comparison of InGaAs(100) Grown by Chemical Beam Epitaxy and Metal Organic Chemical Vapor Deposition

NASA Technical Reports Server (NTRS)

Williams, M. D.; Greene, A. L.; Daniels-Race, T.; Lum, R. M.

2000-01-01

Secondary ion mass spectrometry is used to study the effects of substrate temperature on the composition and growth rate of InGaAs/InP(100) multilayers grown by chemical beam epitaxy, metal-organic chemical vapor deposition and solid source molecular beam epitaxy. The growth kinetics of the material grown by the different techniques are analyzed and compared.

Preparation and characterization of bio-composite PEEK/nHA

NASA Astrophysics Data System (ADS)

Jin, Y. S.; Bian, C. C.; Zhang, Z. Q.; Zhao, Y.; Yang, L.

2017-01-01

PEEK/nHA composite material, with excellent mechanical property as polyetheretherketone (PEEK) and biological activity as hydroxyapatite (HA), has attracted wide attention of medical experts and materials science experts. The addition of hydroxyapatite was the decisive factor for biological activity in PEEK/nHA composite. In this paper, acicular nanohydroxyapatite was prepared by chemical precipitation method with Ca(NO3)2, (NH4)2HPO4 as raw material; PEEK/nHA composite was prepared by solution blending and vacuum sintering method. The composite was characterized with FT-IR, XRD, DSC, TG and mechanical property test. Results showed that the composite has good thermal stability and compressive property when the mass ratio of PEEK to nHA is 10:3; and high nHA content can improve the biological activity of the composite, which can meet the basic requirements for bone tissue engineering scaffold.

Size-resolved chemical composition of aerosol emitted by Erebus volcano, Antarctica

NASA Astrophysics Data System (ADS)

Ilyinskaya, E.; Oppenheimer, C.; Mather, T. A.; Martin, R. S.; Kyle, P. R.

2010-03-01

Persistent, open-vent degassing of Erebus volcano, Antarctica, is a significant point source of gases and aerosol to the austral polar troposphere. We report here on the chemical composition and size distribution of the Erebus aerosol, focusing on the water-soluble fraction. The aerosol was sampled at the rim of the active crater using a cascade impactor, which collected and sized particles in 14 size bins from >10 to 0.01 μm. The soluble fraction of the Erebus aerosol is distinct from other volcanic sources in several respects. It is dominated by chloride-bearing particles (over 30% of total mass) and has an unusually high Cl-/SO42- molar ratio of 3.5. Coarse particles contribute little to the total mass of the soluble fraction. Elevated concentrations of F-, Cl-, Br-, and SO42- are found in a narrow particle size fraction of 0.1-0.25 μm. The detection of particulate Br- reinforces our understanding of the potential for quiescent volcanic emissions to deplete tropospheric ozone. The small aerosol size reflects the low atmospheric temperature and humidity, which inhibit particle growth. Halide-alkali metal salts (Na, K)(Cl, F) appear to be the most abundant species in the aerosol. The concentration of Pb is high compared to other volcanoes; its exsolution may be promoted by the high abundance of halogens in Erebus magma. Despite the previously reported high NOx content in the plume, we did not detect significant quantities of nitrate in the near-vent aerosol. Our findings emphasize the potential regional significance of emissions from Erebus for understanding the Antarctic atmospheric composition and glaciochemical records.

Chemical reactor and method for chemically converting a first material into a second material

DOEpatents

Kong, Peter C.

2008-04-08

A chemical reactor and method for converting a first material into a second material is disclosed and wherein the chemical reactor is provided with a feed stream of a first material which is to be converted into a second material; and wherein the first material is combusted in the chemical reactor to produce a combustion flame, and a resulting gas; and an electrical arc is provided which is passed through or superimposed upon the combustion flame and the resulting gas to facilitate the production of the second material.

Chemical characterization and extractives composition of heartwood and sapwood from Quercus faginea

PubMed Central

Miranda, Isabel; Sousa, Vicelina; Ferreira, Joana; Pereira, Helena

2017-01-01

Heartwood and sapwood of Quercus faginea were evaluated in relation to summative chemical composition and non-polar and polar extracts composition, including an assessment of antioxidant properties (DPPH and FRAP). Twenty trees from two sites in Portugal were analysed. Heartwood had approximately two times more solvent extractible compounds than sapwood (on average 19.0% and 9.5%). The lipophilic extractible compounds were below 1%, and most of them were polar e.g. ethanol-soluble compounds corresponded to 65% of total extractives in heartwood and 43% in sapwood. Lignin content was similar in sapwood and heartwood (28.1% and 28.6% of extractive-free wood respectively) as well as the sugar composition. Site did not influence the chemical composition. The lipophilic extractible compounds from both sapwood and heartwood included mainly saturated fatty acids (23.0% and 36.9% respectively) and aromatic compounds were also abundant in sapwood (22.9%). The ethanol-water extractibles had a high content of phenolic substances (558.0 and 319.4 mg GAE/g extract, respectively of heartwood and sapwood). The polyphenolic composition was similar in heartwood and sapwood with higher content of ellagitannins (168.9 and 153.5 mg tannic acid/g of extract in sapwood and heartwood respectively) and very low content of condensed tannins. The antioxidant activity was very high with IC50 of 2.6 μg/ml and 3.3 μg/ml for sapwood and heartwood respectively, as compared to standard antioxidants (IC50 of 3.8 μg/ml for Trolox). The ferric reducing ability was 2.8 and 2.0 mMol Trolox equivalents/g extract of heartwood and sapwood respectively. The variability between trees was low and no differences between the two sites were found. Q. faginea showed a very good potential for cooperage and other applications for which a source of compounds with antioxidant properties is desirable. PMID:28614371

Composite structural materials

NASA Technical Reports Server (NTRS)

Loewy, Robert G.; Wiberley, Stephen E.

1988-01-01

A decade long program to develop critical advanced composite technology in the areas of physical properties, structural concept and analysis, manufacturing, reliability, and life predictions is reviewed. Specific goals are discussed. The status of the chemical vapor deposition effects on carbon fiber properties; inelastic deformation of metal matrix laminates; fatigue damage in fibrous MMC laminates; delamination fracture toughness in thermoplastic matrix composites; and numerical analysis of composite micromechanical behavior are presented.

Wood chemical composition as related to properties of handsheets made from loblolly pine refiner groundwood

Treesearch

Charles W. McMillin

1969-01-01

Burst and tear strengths of handsheets made from 48 pulps disk-refined from chips of varying chemical composition decreased with incressing extractive content after the independent effects of fiber morphology were specified. This result was attributed to lessened bond strength caused by reduced surface tension forces and blocking of reactive sites on the fiber surfaces...

Fabrication and mechanical evaluation of hydroxyapatite/oxide nano-composite materials.

PubMed

Mohamed, Khaled R; Beherei, Hanan H; El Bassyouni, Gehan T; El Mahallawy, Nahed

2013-10-01

In the current study, the semiconducting metal oxides such as nano-ZnO and SiO2 powders were prepared via sol-gel technique and conducted on nano-hydroxyapatite (nHA) which was synthesized by chemical precipitation. The properties of fabricated nano-structured composites containing different ratios of HA, ZnO and SiO2 were examined using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. The effect of the variation of ratios between the three components on mechanical, microstructure and in-vitro properties was assessed to explore the possibility of enhancing these properties. The results proved that the mechanical properties exhibited an increment with increasing the ZnO content at the extent of HA. In-vitro study proved the formation and nucleation of apatite onto the surface of the fabricated composites after one week of immersion. It is concluded that HA composites containing SiO2 or SiO2/ZnO content had a suitable mechanical properties and ability to form apatite particles onto the composite surface. Based on bioactivity behavior, Si-HA is more bioactive than pure hydroxyapatite and nano-arrangements will provide an interface for better bone formation. Therefore, these nano-composites will be promising as bone substitutes especially in load bearing sites. Copyright © 2013 Elsevier B.V. All rights reserved.

[Comparative study of chemical composition of pomegranate peel pomegranates inside and pomegranate seeds].

PubMed

Zhou, Qian; Sun, Li-Li; Dai, Yan-Peng; Wang, Liang; Su, Ben-Zheng

2013-07-01

An HPLC fingerprint of pomegranate peel was established. Using chromatographic conditions, we compared the chemical composition of pomegranate peel, inside and seeds, and simultaneously determined the contents of gallic acid and ellagic acid. By comparison, we found that there were no significant differences between pomegranate peel and inside, but there was a big difference between pomegranate seeds and another two. The contents of gallic acid and ellagic acid of pomegranate peel respectively were 0.33%, 0.59%, while in pomegranate inside the result respectively were 0.52%, 0.38%. Content of ellagic acid from pomegranate seeds was only 0.01%. By study, we thought that when pomegranate peel was processed, pomegranate seeds should be removed, while pomegranate inside could be retained on the premise of full drying.

Chemical characterization of selected LDEF polymeric materials

NASA Technical Reports Server (NTRS)

Young, Philip R.; Slemp, Wayne S.

1991-01-01

Chemical characterization of selected polymeric materials which received exposure on the Long Duration Exposure Facility (LDEF) is reported. The specimens examined include silvered fluorinated ethylene propylene Teflon thermal blanket material, polysulfone, epoxy, polyimide matrix resin/graphite fiber reinforced composites, and several high performance polymer films. These specimens came from numerous LDEF locations, and thus received different environmental exposures. The results to date show no significant change at the molecular level in the polymer that survived exposure. Scanning electron and scanning tunneling microscopes show resin loss and a texturing of some specimens which resulted in a change in optical properties. The potential effect of a silicon-containing molecular contamination on these materials is addressed. The possibility of continued post-exposure degradation of some polymeric films is also proposed.

[Determination of the content of sulfur of coal by the infrared absorption method with high acccuracy].

PubMed

Wang, Hai-Feng; Lu, Hai; Li, Jia; Sun, Guo-Hua; Wang, Jun; Dai, Xin-Hua

2014-02-01

The present paper reported the differential scanning calorimetry-thermogravimetry curves and the infrared (IR) absorption spectrometry under the temperature program analyzed by the combined simultaneous thermal analysis-IR spectrometer. The gas products of coal were identified by the IR spectrometry. This paper emphasized on the combustion at high temperature-IR absorption method, a convenient and accurate method, which measures the content of sulfur in coal indirectly through the determination of the content of sulfur dioxide in the mixed gas products by IR absorption. It was demonstrated, when the instrument was calibrated by varied pure compounds containing sulfur and certified reference materials (CRMs) for coal, that there was a large deviation in the measured sulfur contents. It indicates that the difference in chemical speciations of sulfur between CRMs and the analyte results in a systematic error. The time-IR absorption curve was utilized to analyze the composition of sulfur at low temperatures and high temperatures and then the sulfur content of coal sample was determined by using a CRM for coal with a close composition of sulfur. Therefore, the systematic error due to the difference in chemical speciations of sulfur between the CRM and analyte was eliminated. On the other hand, in this combustion at high temperature-IR absorption method, the mass of CRM and analyte were adjusted to assure the sulfur mass equal and then the CRM and the analyte were measured alternately. This single-point calibration method reduced the effect of the drift of the IR detector and improved the repeatability of results, compared with the conventional multi-point calibration method using the calibration curves of signal intensity vs sulfur mass. The sulfur content results and their standard deviations of an anthracite coal and a bituminous coal with a low sulfur content determined by this modified method were 0.345% (0.004%) and 0.372% (0.008%), respectively. The uncertainty (U

Correlation of rocket propulsion fuel properties with chemical composition using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry followed by partial least squares regression analysis

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

Kehimkar, Benjamin; Hoggard, Jamin C.; Marney, Luke C.

There is an increased need to more fully assess and control the composition of kerosene based rocket propulsion fuels, namely RP-1 and RP-2. In particular, it is crucial to be able to make better quantitative connections between the following three attributes: (a) fuel performance, (b) fuel properties (flash point, density, kinematic viscosity, net heat of combustion, hydrogen content, etc) and (c) the chemical composition of a given fuel (i.e., specific chemical compounds and compound classes present as a result of feedstock blending and processing). Indeed, recent efforts in predicting fuel performance through modeling put greater emphasis on detailed and accuratemore » fuel properties and fuel compositional information. In this regard, advanced distillation curve (ADC) metrology provides improved data relative to classical boiling point and volatility curve techniques. Using ADC metrology, data obtained from RP-1 and RP-2 fuels provides compositional variation information that is directly relevant to predictive modeling of fuel performance. Often, in such studies, one-dimensional gas chromatography (GC) combined with mass spectrometry (MS) is typically employed to provide chemical composition information. Building on approaches using GC-MS, but to glean substantially more chemical composition information from these complex fuels, we have recently studied the use of comprehensive two dimensional gas chromatography combined with time-of-flight mass spectrometry (GC × GC - TOFMS) to provide chemical composition data that is significantly richer than that provided by GC-MS methods. In this report, by applying multivariate data analysis techniques, referred to as chemometrics, we are able to readily model (correlate) the chemical compositional information from RP-1 and RP-2 fuels provided using GC × GC - TOFMS, to the fuel property information such as that provided by the ADC method and other specification properties. We anticipate that this new chemical analysis

New composite materials prepared by calcium phosphate precipitation in chitosan/collagen/hyaluronic acid sponge cross-linked by EDC/NHS.

PubMed

Kaczmarek, B; Sionkowska, A; Kozlowska, J; Osyczka, A M

2018-02-01

Nowadays, fabrication of composite materials based on biopolymers is a rising field due to potential for bone repair and tissue engineering application. Blending of different biopolymers and incorporation of inorganic particles in the blend can lead to new materials with improved physicochemical properties and biocompatibility. In this work 3D porous structures called scaffolds based on chitosan, collagen and hyaluronic acid were obtained through the lyophilization process. Scaffolds were cross-linked by EDC/NHS. Infrared spectra for the materials were made, the percentage of swelling, scaffolds porosity and density, mechanical parameters, thermal stability were studied. Moreover, the scaffolds were used as matrixes for the calcium phosphate in situ precipitation. SEM images were taken and EDX analysis was carried out for calcium and phosphorous content determination in the scaffold. In addition, the adhesion and proliferation of human osteosarcoma SaOS-2 cells was examined on obtained scaffolds. The results showed that the properties of 3D composites cross-linked by EDC/NHS were altered after the addition of 1, 2 and 5% hyaluronic acid. Mechanical parameters, thermal stability and porosity of scaffolds were improved. Moreover, calcium and phosphorous were found in each kind of scaffold. SEM images showed that the precipitation was homogeneously carried in the whole volume of samples. Attachment of SaOS-2 cells to all modified materials was better compared to unmodified control and proliferation of these cells was markedly increased on scaffolds with precipitated calcium phosphate. Obtained materials can provide the support useful in tissue engineering and regenerative medicine. Copyright © 2017 Elsevier B.V. All rights reserved.

Multi-material composites prepared by additive manufacturing and melt casting

NASA Astrophysics Data System (ADS)

Murialdo, Maxwell; Sullivan, Kyle; White, Bradley; LLNL MSD Collaboration

2017-06-01

Recent advances in additive manufacturing have disrupted not only means of production, but also have enabled a new parameter space of multiscale materials designs. Understanding the role of architecture to control material response is being investigated for a wide range of applications, from light-weight structural components to energetic materials. In this work, we combine 3D printing of scaffold structures with a subsequent melt-infiltration step to render an architected multi-material composite article. Both the scaffold architecture and material type were investigated. The processing challenges of filling such scaffolds using a melt-infiltration step will be discussed, along with our progress in this area. Using the combined method of printing and casting, we will discuss our path forward for testing the mechanical properties and the high-strain response of our composite architected parts. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. IM release: LLNL-ABS-725497-DRAFT.

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Wiberley, S. E.

1978-01-01

The purpose of the RPI composites program is to develop advanced technology in the areas of physical properties, structural concepts and analysis, manufacturing, reliability and life prediction. Concommitant goals are to educate engineers to design and use composite materials as normal or conventional materials. A multifaceted program was instituted to achieve these objectives.

Grouping of Petroleum Substances as Example UVCBs by Ion Mobility-Mass Spectrometry to Enable Chemical Composition-Based Read-Across.

PubMed

Grimm, Fabian A; Russell, William K; Luo, Yu-Syuan; Iwata, Yasuhiro; Chiu, Weihsueh A; Roy, Tim; Boogaard, Peter J; Ketelslegers, Hans B; Rusyn, Ivan

2017-06-20

Substances of Unknown or Variable composition, Complex reaction products, and Biological materials (UVCBs), including many refined petroleum products, present a major challenge in regulatory submissions under the EU Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) and US High Production Volume regulatory regimes. The inherent complexity of these substances, as well as variability in composition obfuscates detailed chemical characterization of each individual substance and their grouping for human and environmental health evaluation through read-across. In this study, we applied ion mobility mass spectrometry in conjunction with cheminformatics-based data integration and visualization to derive substance-specific signatures based on the distribution and abundance of various heteroatom classes. We used petroleum substances from four petroleum substance manufacturing streams and evaluated their chemical composition similarity based on high-dimensional substance-specific quantitative parameters including m/z distribution, drift time, carbon number range, and associated double bond equivalents and hydrogen-to-carbon ratios. Data integration and visualization revealed group-specific similarities for petroleum substances. Observed differences within a product group were indicative of batch- or manufacturer-dependent variation. We demonstrate how high-resolution analytical chemistry approaches can be used effectively to support categorization of UVCBs based on their heteroatom composition and how such data can be used in regulatory decision-making.

Classification and statistical analysis of mine spoils chemical composition from Oliete basin (Teruel, NE Spain)

NASA Astrophysics Data System (ADS)

Meseguer, S.; Sanfeliu, T.; Jordán, M. M.

2009-02-01

The Oliete basin (Early Cretaceous, NE Teruel, Spain) is one of the most important areas for the supply of mine spoils used as ball clays for the production of white and red stoneware in the Spanish ceramic industry of wall and floor tiles. This study corresponds to the second part of the paper published recently by Meseguer et al. (Environ Geol 2008) about the use of mine spoils from Teruel coal mining district. The present study shows a statistical data analysis from chemical data (major, minor and trace elements). The performed statistical analysis of chemical data included descriptive statistics and cluster analysis (with ANOVA and Scheffé methods). The cluster analysis of chemical data provided three main groups: C3 with the highest mean SiO2 content (66%) and lowest mean Al2O3 content (20%); C2 with lower SiO2 content (48%) and higher mean Al2O3 content (28%); and C1 with medium values for the SiO2 and Al2O3 mean content. The main applications of these materials are refractory, white and red ceramics, stoneware, heavy ceramics (including red earthenware, bricks and roof tiles), and components of white Portland cement and aluminous cement. Clays from group 2 are used in refractories (with higher kaolinite content, and constrictions to CaO + MgO and K2O + Na2O contents). All materials can be used in fine ceramics (white or red, according to the Fe2O3 + TiO2 content).

Effect of harvesting frequency, variety and leaf maturity on nutrient composition, hydrogen cyanide content and cassava foliage yield.

PubMed

Hue, Khuc Thi; Thanh Van, Do Thi; Ledin, Inger; Wredle, Ewa; Spörndly, Eva

2012-12-01

The experiment studied the effect of harvesting frequencies and varieties on yield, chemical composition and hydrogen cyanide content in cassava foliage. Foliage from three cassava varieties, K94 (very bitter), K98-7 (medium bitter) and a local (sweet), were harvested in three different cutting cycles, at 3, 6 and 9 months; 6 and 9 months and 9 months after planting, in a 2-yr experiment carried out in Hanoi, Vietnam. Increasing the harvesting frequency increased dry matter (DM) and crude protein (CP) production in cassava foliage. The K94 variety produced higher foliage yields than the other two varieties. Dry matter, neutral detergent fibre (NDF), acid detergent fibre (ADF) and total tannin content increased with months to the first harvest, whereas CP content decreased. Hydrogen cyanide (HCN) content was lower at the first harvest than at later harvests for all cutting cycles. At subsequent harvests the content of total tannins tended to decline, while HCN content increased (p<0.05). Chemical composition differed somewhat across varieties except for total tannins and ash. Dry matter, NDF, ADF and total tannins were higher in fully matured leaves, while CP and HCN were lower in developing leaves.

Effect of Harvesting Frequency, Variety and Leaf Maturity on Nutrient Composition, Hydrogen Cyanide Content and Cassava Foliage Yield

PubMed Central

Hue, Khuc Thi; Thanh Van, Do Thi; Ledin, Inger; Wredle, Ewa; Spörndly, Eva

2012-01-01

The experiment studied the effect of harvesting frequencies and varieties on yield, chemical composition and hydrogen cyanide content in cassava foliage. Foliage from three cassava varieties, K94 (very bitter), K98-7 (medium bitter) and a local (sweet), were harvested in three different cutting cycles, at 3, 6 and 9 months; 6 and 9 months and 9 months after planting, in a 2-yr experiment carried out in Hanoi, Vietnam. Increasing the harvesting frequency increased dry matter (DM) and crude protein (CP) production in cassava foliage. The K94 variety produced higher foliage yields than the other two varieties. Dry matter, neutral detergent fibre (NDF), acid detergent fibre (ADF) and total tannin content increased with months to the first harvest, whereas CP content decreased. Hydrogen cyanide (HCN) content was lower at the first harvest than at later harvests for all cutting cycles. At subsequent harvests the content of total tannins tended to decline, while HCN content increased (p<0.05). Chemical composition differed somewhat across varieties except for total tannins and ash. Dry matter, NDF, ADF and total tannins were higher in fully matured leaves, while CP and HCN were lower in developing leaves. PMID:25049534

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

1983-01-01

Transverse properties of fiber constituents in composites, fatigue in composite materials, matrix dominated properties of high performance composites, numerical investigation of moisture effects, numerical investigation of the micromechanics of composite fracture, advanced analysis methods, compact lug design, and the RP-1 and RP-2 sailplanes projects are discussed.

Impact of the material composition on proton range variation - A Monte Carlo study

NASA Astrophysics Data System (ADS)

Wu, S. W.; Tung, C. J.; Lee, C. C.; Fan, K. H.; Huang, H. C.; Chao, T. C.

2015-11-01

In this study, we used the Geant4 toolkit to demonstrate the impacts of the material composition of tissues on proton range variation. Bragg curves of different materials subjected to a 250 MeV mono-energy proton beam were simulated and compared. These simulated materials included adipose, heart, brain, cartilage, cortical bone and water. The results showed that there was significant proton range deviation between Bragg curves, especially for cortical bone. The R50 values for a 250 MeV proton beam were approximately 39.55 cm, 35.52 cm, 37.00 cm, 36.51 cm, 36.72 cm, 22.53 cm, and 38.52 cm in the phantoms that were composed completely of adipose, cartilage, tissue, heart, brain, cortical bone, and water, respectively. Mass density and electron density were used to scale the proton range for each material; electron density provided better range scaling. In addition, a similar comparison was performed by artificially setting all material density to 1.0 g/cm3 to evaluate the range deviation due to chemical components alone. Tissue heterogeneity effects due to density variation were more significant, and less significant for chemical composition variation unless the Z/A was very different.

Effect of chemical composition on corneal cellular response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid.

PubMed

Lai, Jui-Yang

2013-10-01

Characterization of corneal cellular response to hydrogel materials is an important issue in ophthalmic applications. In this study, we aimed to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and material compatibility towards corneal stromal and endothelial cells. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Results of electrokinetic measurements showed that an increase in absolute zeta potential of photopolymerized membranes is observed with increasing the volume ratios of AAc/HEMA. Following 4 days of incubation with various hydrogels, the primary rabbit corneal stromal and endothelial cell cultures were examined for viability, proliferation, and pro-inflammatory gene expression. The samples prepared from the solution mixture containing 0-10 vol.% AAc displayed good cytocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the decreased viability, inhibited proliferation, and stimulated inflammation were noted in both cell types, probably due to the stronger charge-charge interactions. On the other hand, the ionic pump function of corneal endothelial cells exposed to photopolymerized membranes was examined by analyzing the Na(+),K(+)-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of material samples having higher anionic charge density (i.e., zeta potential of -38 to -56 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal stromal and endothelial cell responses to polymeric biomaterials. Copyright © 2013 Elsevier B.V. All rights reserved.

HA and double-layer HA-P2O5/CaO glass coatings: influence of chemical composition on human bone marrow cells osteoblastic behavior.

PubMed

Ferraz, M P; Fernandes, M H; Santos, J D; Monteiro, F J

2001-07-01

Human osteoblastic bone marrow derived cells were cultured for 28 days onto the surface of a glass reinforced hydroxyapatite (HA) composite and a commercial type HA plasma sprayed coatings, both in the "as-received" condition and after an immersion treatment with culture medium during 21 days. Cell proliferation and differentiation were analyzed as a function of the chemical composition of the coatings and the immersion treatment. Cell attachment, growth and differentiation of osteoblastic bone marrow cells seeded onto "as-received" plasma sprayed coatings were strongly affected by the time-dependent variation of the surface structure occurring during the first hours of culture. Initial interactions leading to higher amounts of adsorbed protein and zeta potential shifts towards negative charges appeared to result in surface structures with better biological performance. Cultures grown onto the pretreated coatings showed higher rate of cell proliferation and increased functional activity, as compared to those grown onto the corresponding "as-received" materials. However, the cell behavior was similar in the glass composite and HA coatings. The results showed that the glass composites present better characteristics for bone cell growth and function than HA. In addition, this work also provide evidence that the biological performance of the glass composites can be modulated and improved by manipulations in the chemical composition, namely in the content of glass added to HA. Copyright 2001 Kluwer Academic Publishers

Physical metallurgy and mechanical behaviour of FeCrWTaV low activation martensitic steels: Effects of chemical composition

NASA Astrophysics Data System (ADS)

Alamo, A.; Brachet, J. C.; Castaing, A.; Lepoittevin, C.; Barcelo, F.

1998-10-01

This paper essentially deals with chemical composition effects on metallurgical and mechanical behaviour of Fe-7.5/11CrWVTa low activation martensitic steels. Materials investigated are experimental alloys as well as large-scale heats having different contents of Cr (7.5-11%), Ta (0-0.1%), W (0.8-3%) and interstitial elements, like carbon (0.09-0.17%) and nitrogen (0.004-0.045%). For this purpose, phase transformation during heating and cooling have been investigated in anisothermal and isothermal conditions to establish the corresponding Continuous Cooling Transformation (CCT) and Time-Temperature-Transformation (TTT) diagrams. Austenitisation (normalisation) and tempering treatments were performed in a wide range of temperatures. Tensile and impact properties as a function of composition and metallurgical conditions have been determined and compared to 9Cr-1Mo conventional martensitic steels.

[Comparison of green coffee beans volatiles chemical composition of Hainan main area].

PubMed

Hu, Rong-Suo; Chu, Zhong; Gu, Feng-Lin; Lu, Min-Quan; Lu, Shao-Fang; Wu, Gui-Ping; Tan, Le-He

2013-02-01

Chemical component of Hainan green coffee beans was analyzed with solid phase microextraction-gas chromatography-mass spectrometry, and the discrepancy between two green coffee beans was differentiated through the spectrum database retrieval and retention index of compound characterization. The experimental results show that: the chemical composition of Wanning coffee beans and Chengmai coffee beans is basically the same. The quantity of analyzed compound in Wanning area coffee is 91, and in Chengmai area coffee is 106, the quantity of the same compound is 66, and the percent of the same component is 75.52%. The same compounds accounted for 89.86% of the total content of Wanning area coffee, and accounted for 85.70% of the total content of Chengmai area coffee.

Effect of Sericin on Mechanical Behavior of Composite Material Reinforced by Silk Woven Fabric

NASA Astrophysics Data System (ADS)

Kimura, Teruo; Ino, Haruhiro; Hanada, Koji; Katori, Sigetaka

Recent, attention has been given to shift from glass fibers and carbon fibers to natural fibers for FRP composites for the goal of protecting the environment. This paper concerned with the application of silk fabric for composite materials. Polypropylene (PP) was used for the matrix material and the silk fabric composites were molded using a compression molding method. Especially, the effect of sericin on mechanical behaviors of composite materials was discussed. Good adhesion between silk and PP was obtained by removing the sericin existing around the fibroin. The tensile modulus of composite decreased with decreasing the sericin because of the flexibility of silk fibers without sericin. In particular, the higher Izod impact value was obtained for the composites containing the silk fibers without sericin.

Surface chemical composition of human maxillary first premolar as assessed by X-ray photoelectron spectroscopy (XPS)

NASA Astrophysics Data System (ADS)

Lou, Leo; Nelson, Alan E.; Heo, Giseon; Major, Paul W.

2008-08-01

The surface chemical composition of dental enamel has been postulated as a contributing factor in the variation of bond strength of brackets bonded to teeth, and hence, the probability of bracket failure during orthodontic treatment. This study systematically investigated the chemical composition of 98 bonding surfaces of human maxillary premolars using X-ray photoelectron spectroscopy (XPS) to ascertain compositional differences between right and left first premolars. The major elements detected in all samples were calcium, phosphorus, oxygen, nitrogen and carbon. Surface compositions were highly variable between samples and several elements were found to be highly correlated. No statistical significant difference in the chemical composition of the maxillary right and left first premolars was found ( p > 0.05). Knowledge of the chemical composition of enamel surfaces will facilitate future studies that relate this information to the variations in dental enamel bond strength.

Yield, chemical composition and nutritional quality responses of carrot, radish and turnip to elevated atmospheric carbon dioxide.

PubMed

Azam, Andaleeb; Khan, Ikhtiar; Mahmood, Abid; Hameed, Abdul

2013-10-01

Future concentration of carbon dioxide in the atmosphere is very important due to its apparent economic and environmental impact in terms of climate change. However, a compressive assessment of its effect on the nutritional and chemical characteristics of food crops has yet to be established. In the present study the impact of elevated atmospheric CO2 on the yield, chemical composition and nutritional quality of three root vegetables, carrot (Daucus carota L. cv. T-1-111), radish (Raphanus sativus L. cv. Mino) and turnip (Brassica rapa L. cv. Grabe) has been investigated. The yield of carrot, radish and turnip increased by 69, 139 and 72%, respectively, when grown under elevated CO2 conditions. Among the proximate composition, protein, vitamin C and fat contents decreased significantly for all the vegetables while sugar and fibre contents were increased. Response of the vegetables to elevated CO2 , in terms of elemental composition, was different with a significant decrease in many important minerals. Elevated CO2 decreased the amount of majority of the fatty acids and amino acids in these vegetables. It was observed that elevated CO2 increased the yield of root vegetables but many important nutritional parameters including protein, vitamin C, minerals, essential fatty acids and amino acids were decreased. © 2013 Society of Chemical Industry.

Recent advances on polyoxometalate-based molecular and composite materials.

PubMed

Song, Yu-Fei; Tsunashima, Ryo

2012-11-21

Polyoxometalates (POMs) are a subset of metal oxides with unique physical and chemical properties, which can be reliably modified through various techniques and methods to develop sophisticated materials and devices. In parallel with the large number of new crystal structures reported in the literature, the application of these POMs towards multifunctional materials has attracted considerable attention. This critical review summarizes recent progress on POM-based molecular and composite materials, and particularly highlights the emerging areas that are closely related to surface, electronic, energy, environment, life science, etc. (171 references).

Electrical property of macroscopic graphene composite fibers prepared by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Sun, Haibin; Fu, Can; Gao, Yanli; Guo, Pengfei; Wang, Chunlei; Yang, Wenchao; Wang, Qishang; Zhang, Chongwu; Wang, Junya; Xu, Junqi

2018-07-01

Graphene fibers are promising candidates in portable and wearable electronics due to their tiny volume, flexibility and wearability. Here, we successfully synthesized macroscopic graphene composite fibers via a two-step process, i.e. first electrospinning and then chemical vapor deposition (CVD). Briefly, the well-dispersed PAN nanofibers were sprayed onto the copper surface in an electrified thin liquid jet by electrospinning. Subsequently, CVD growth process induced the formation of graphene films using a PAN-solid source of carbon and a copper catalyst. Finally, crumpled and macroscopic graphene composite fibers were obtained from carbon nanofiber/graphene composite webs by self-assembly process in the deionized water. Temperature-dependent conduct behavior reveals that electron transport of the graphene composite fibers belongs to hopping mechanism and the typical electrical conductivity reaches 4.59 × 103 S m‑1. These results demonstrated that the graphene composite fibers are promising for the next-generation flexible and wearable electronics.

Electrical property of macroscopic graphene composite fibers prepared by chemical vapor deposition.

PubMed

Sun, Haibin; Fu, Can; Gao, Yanli; Guo, Pengfei; Wang, Chunlei; Yang, Wenchao; Wang, Qishang; Zhang, Chongwu; Wang, Junya; Xu, Junqi

2018-07-27

Graphene fibers are promising candidates in portable and wearable electronics due to their tiny volume, flexibility and wearability. Here, we successfully synthesized macroscopic graphene composite fibers via a two-step process, i.e. first electrospinning and then chemical vapor deposition (CVD). Briefly, the well-dispersed PAN nanofibers were sprayed onto the copper surface in an electrified thin liquid jet by electrospinning. Subsequently, CVD growth process induced the formation of graphene films using a PAN-solid source of carbon and a copper catalyst. Finally, crumpled and macroscopic graphene composite fibers were obtained from carbon nanofiber/graphene composite webs by self-assembly process in the deionized water. Temperature-dependent conduct behavior reveals that electron transport of the graphene composite fibers belongs to hopping mechanism and the typical electrical conductivity reaches 4.59 × 10 3 S m -1 . These results demonstrated that the graphene composite fibers are promising for the next-generation flexible and wearable electronics.

Photocatalytic water splitting: Materials design and high-throughput screening of molecular compositions

NASA Astrophysics Data System (ADS)

Khnayzer, Rony S.

Due to the expected increases on energy demand in the near future, the development of new catalytic molecular compositions and materials capable of directly converting water, with the aid of solar photons, into hydrogen becomes obviated. Hydrogen is a combustible fuel and precious high-energy feedstock chemical. However, for the water-splitting reaction to proceed efficiently and economically enough for large-scale application, efficient light-absorbing sensitizers and water splitting catalysts are required. To study the kinetics of the water reduction reaction, we have used titania (TiO2) nanoparticles as a robust scaffold to photochemically grow platinum (Pt) nanoparticles from a unique surface-anchored molecular precursor Pt(dcbpy)Cl2 [dcbpy = 4,4'-dicarboxylic acid-2,2'-bipyridine]. The hybrid Pt/TiO 2 nanomaterials obtained were shown to be a superior water reduction catalyst (WRC) in aqueous suspensions when compared with the benchmark platinized TiO2. In addition, cobalt phosphate (CoPi) water oxidation catalyst (WOC) was photochemically assembled on the surface of TiO2, and its structure and mechanism of activity showed resemblance to the established electrochemically grown CoPi material. Both WRC and WOC described above possessed near unity Faradaic efficiency for hydrogen and oxygen production respectively, and were fully characterized by electron microscopy, x-ray absorption spectroscopy, electrochemistry and photochemistry. While there are established materials and molecules that are able to drive water splitting catalysis, some of these efficient semiconductors, including titanium dioxide (TiO2) and tungsten trioxide (WO3), are only able to absorb high-energy (ultraviolet or blue) photons. This high-energy light represents merely a fraction of the solar spectrum that strikes the earth and the energy content of those remaining photons is simply wasted. A strategy to mitigate this problem has been developed over the years in our laboratory. Briefly

Physical and Chemical Characterization Of Greater Yam (Dioscorea Alata) And Jack Bean (Canavalia Ensiformis) - Based Composite Flour

NASA Astrophysics Data System (ADS)

Affandi, D. R.; Praseptiangga, D.; Nirmala, F. S.; Sigit Amanto, B.; Atmaka, W.

2017-04-01

Indonesia is a tropical country that has great potential in agriculture. Tubers and legumes as examples of the potential commodities are needed to be more developed. Flour production is one of the best alternatives to be chosen as the downstream stage of the tubers and legumes utilization. Greater yam (Dioscorea alata) and jack bean (Canavalia ensiformis) were used in this study. This study was conducted to determine best formula of composite flour based on physical, chemical, and functional characterization of composite flour produced. Variations of formula used was the ratio of greater yam flour and jack bean flour, which were 85:15 (F1), 70:30 (F2), 55:45 (F3), respectively, and this study was conducted using completely randomized design (CRD). The formula variations didn’t show any significant effect on the water absorption capability, water holding capacity (WHC), oil holding capacity (OHC), swelling power, and starch content of the composite flour. However, the formula variations had a significant influence on the colour, proximate parameters, amylose and amylopectin content, resistant starch content, dietary fibre, total phenol, and antioxidant activity of the composite flour produced. Considering the results of physical, chemical, and functional characteristics of composite flour, formula (F1) was selected as the best composite flour developed from greater yam and jack bean flours.

Single particle measurements of the chemical composition of cirrus ice residue during CRYSTAL-FACE

NASA Astrophysics Data System (ADS)

Cziczo, D. J.; Murphy, D. M.; Hudson, P. K.; Thomson, D. S.

2004-02-01

The first real-time, in situ, investigation of the chemical composition of the residue of cirrus ice crystals was performed during July 2002. This study was undertaken on a NASA WB-57F high-altitude research aircraft as part of CRYSTAL-FACE, a field campaign which sought to further our understanding of the relation of clouds, water vapor, and climate by characterizing, among other parameters, anvil cirrus formed about the Florida peninsula. A counter flow virtual impactor (CVI) was used to separate cirrus ice from the unactivated interstitial aerosol particles and evaporate condensed-phase water. Residual material, on a crystal-by-crystal basis, was subsequently analyzed using the NOAA Aeronomy Laboratory's Particle Analysis by Laser Mass Spectrometry (PALMS) instrument. Sampling was performed from 5 to 15 km altitude and from 12° to 28° north latitude within cirrus originating over land and ocean. Chemical composition measurements provided several important results. Sea salt was often incorporated into cirrus, consistent with homogeneous ice formation by aerosol particles from the marine boundary layer. Size measurements showed that large particles preferentially froze over smaller ones. Meteoritic material was found within ice crystals, indicative of a relation between stratospheric aerosol particles and tropospheric clouds. Mineral dust was the dominant residue observed in clouds formed during a dust transport event from the Sahara, consistent with a heterogeneous freezing mechanism. These results show that chemical composition and size are important determinants of which aerosol particles form cirrus ice crystals.

Immediate impact on the rim zone of cement based materials due to chemical attack

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

Schwotzer, M., E-mail: matthias.schwotzer@kit.edu; Scherer, T.; Gerdes, A.

2015-01-15

Cement based materials are in their widespread application fields exposed to various aqueous environments. This can lead to serious chemical changes affecting the durability of the materials. In particular in the context of service life prediction a detailed knowledge of the reaction mechanisms is a necessary base for the evaluation of the aggressivity of an aqueous medium and this is deduced commonly from long term investigations. However, these processes start immediately at the material/water-interface, when a cementitious system comes into contact with an aqueous solution, altering here the chemical composition and microstructure. This rim zone represents the first hurdle thatmore » has to be overcome by an attacking aqueous solution. Therefore, the properties of the surface near area should be closely associated with the further course of deterioration processes by reactive transport. In this context short term exposure experiments with hardened cement paste over 4 and 48 h have been carried out with demineralized water, hard tap water and different sulfate solutions. In order to investigate immediate changes in the near-surface region, depth profile cuts have been performed on the cement paste samples by means of focused ion beam preparation techniques. A scanning beam of Gallium ions is applied to cut a sharp edge in the cement paste surface, providing insights into the composition and microstructure of the upper ten to hundred microns. Electron microscopic investigations on such a section of the rim zone, together with surface sensitive X-ray diffraction accompanied by a detailed characterization of the bulk composition confirm that the properties of the material/water interface are of relevance for the durability of cement based systems in contact with aqueous solutions. In this manner, focused ion beam investigations constitute auspicious tools to contribute to a more sophisticated understanding of the reaction mechanisms. - Highlights: • The chemical

Lunar Skylights and Their Chemical Compositions

NASA Astrophysics Data System (ADS)

Wong, J.; Torres, J.; FitzHoward, S.; Luu, E.; Hua, J.; Irby, R.

2013-12-01

In 2009, the Japanese orbiter, SELenological and Engineering Explorer (SELENE) discovered a skylight on the near side of the moon. Skylights are collapsed ceilings of rilles, thought to be caused by moonquakes, meteoroids, or incomplete formation of these lava tube ceilings. Since then, NASA's Lunar Reconnaissance Orbiter has discovered two more skylights, also located on the near side of the moon. Previous research has shown that the physical characteristics of known rilles, can be used as indicators of the presence of yet undiscovered rille and lava dome locations across the lunar surface. We hypothesize that skylights have a signature chemical composition that is unique, and can be used to predict the location of additional skylights on the surface of the moon. For this study, we compared chemical composition data of the three mare sites containing skylights with the 21 mare sites without skylights. Using the software JMARS for the Moon, we compiled multiple datasets to measure the concentrations of 13 different chemical compounds including calcium, iron oxide, titanium dioxide, and thorium. We then conducted a two-tailed T-test of the data, which generated probability values for the mean differences across all 13 chemical compounds of the maria sites with skylights and the maria sites without skylights. Our results show that there is no statistical difference in chemical composition across all of the maria sites examined. Therefore, we conclude that chemical composition does not predict or indicate potential skylight locations on the moon. Further research on other skylight characteristics, for example depth and surrounding underground lava channels, may shed light on the relationships between mare and skylights locations. Three Skylight Locations Found on Lunar Surface 100m View of Mare Tranquilitatis Skylight

Characterization of Inorganic Filler Content, Mechanical Properties, and Light Transmission of Bulk-fill Resin Composites.

PubMed

Fronza, B M; Ayres, Apa; Pacheco, R R; Rueggeberg, F A; Dias, Cts; Giannini, M

The aims of this study were to characterize inorganic content (IC), light transmission (LT), biaxial flexural strength (BFS), and flexural modulus (FM) of one conventional (layered) and four bulk-fill composites at different depths. Bulk-fill composites tested were Surefil SDR flow (SDR), Filtek Bulk Fill (FBF), Tetric EvoCeram Bulk Fill (TEC), and EverX Posterior (EXP). Herculite Classic (HER) was used as a control. Energy dispersive x-ray analysis and scanning electron microscopy were used to characterize filler particle composition and morphology. The LT through different composite thicknesses (1, 2, 3, and 4 mm) was measured using a laboratory-grade spectral radiometer system (n=5). For the BFS and FM tests, sets of eight stacked composite discs (0.5-mm thick) were prepared simulating bulk filling of a 4-mm-thick increment (n=8). SDR demonstrated larger, irregular particles than those observed in TEC or HER. Filler particles in FBF were spherical, while those in EXP were composed of fiberglass strands. The LT decreased with increased composite thickness for all materials. Bulk-fill composites allowed higher LT than the HER. Furthermore, HER proved to be the unique material, having lower BFS values at deeper regions. SDR, FBF, and TEC bulk-fill composites presented reduced FM with increasing composite depth. The bulk-fill composites investigated exhibited higher LT, independent of different filler content and characteristics. Although an increase in composite thickness reduced LT, the BFS of bulk-fill composites at deeper layers was not compromised.

Neem cake: chemical composition and larvicidal activity on Asian tiger mosquito.

PubMed

Nicoletti, Marcello; Mariani, Susanna; Maccioni, Oliviero; Coccioletti, Tiziana; Murugan, Kardaray

2012-07-01

New pesticides based on natural products are urgently needed, in consideration of their environmental care and lower collateral effects. Neem oil, the main product obtained from Azadiractha indica A. Juss, commonly known as neem tree, is mainly used in medical devices, cosmetics and soaps, as well as important insecticide. Manufacturing of neem oil first includes the collection of the neem seeds as raw material used for the extraction. Neem cake is the waste by-product remaining after extraction processes. The quality of the oil, as that of the cake, strictly depends from the quality of seeds as well as from the type of extraction processes used, which strongly influences the chemical composition of the product. Currently, the different types of commercial neem cake on the market are roughly identified as oiled and deoiled cake, but several other differences can be detected. The differences are relevant and must be determined, to obtain the necessary correlation between chemical constitution and larvicidal activities. Six different batches of neem cake, marketed by several Indian and European companies, were analyzed by HPLC and HPTLC, and their fingerprints compared, obtaining information about the different compositions, focusing in particular on nortriterpenes, considered as the main active components of neem oil. Therefore, the chemical composition of each cake was connected with the biological activitiy, i.e., the effects of the extracts of the six neem cakes were tested on eggs and larvae of Aedes albopictus (Stegomyia albopicta) (Diptera: Culicidae), commonly known as Asian tiger mosquito. The results confirmed the previously reported larvicide effects of neem cake that, however, can now be related to the chemical composition, in particular with nortriterpenes, allowing in that way to discriminate between the quality of the various marketed products, as potential domestic insecticides.

Within-storm and Seasonal Differences in Particulate Organic Material Composition and Sources in White Clay Creek, USA

NASA Astrophysics Data System (ADS)

Karwan, D. L.; Aufdenkampe, A. K.; Aalto, R. E.; Newbold, J. D.; Pizzuto, J. E.

2011-12-01

The material exported from a watershed reflects its origin and the processes it undergoes during downhill and downstream transport. Due to its nature as a complex mixture of material, the composition of POM integrates the physical, biological, and chemical processes effecting watershed material. In this study, we integrate sediment fingerprint analyses common in geomorphological studies of mineral suspended particulate material (SPM) with biological and ecological characterizations of particulate organic carbon (POC). Through this combination, we produce quantifiable budgets of particulate organic carbon and mineral material, as well as integrate our calculations of carbon and mineral cycling in a complex, human-influenced watershed. More specifically, we quantify the composition and sources of POM in the third-order White Clay Creek Watershed, and examine the differences in composition and source with hydrologic variations produced by storms and seasonality. POM and watershed sources have been analyzed for particle size, mineral surface area, total mineral elemental composition, fallout radioisotope activity for common erosion tracers (7Be, 210Pb, 137Cs), and organic carbon and nitrogen content with stable isotope (13C, 15N) abundance. Results indicate a difference in POM source with season as well as within individual storms. Beryllium-7 activity, an indicator of landscape surface erosion, nearly triples within a single spring storm, from 389 mBq/g on the rising limb and 1190 mBq/g at the storm hydrograph peak. Fall storms have even lower 7Be concentrations, below 100 mBq/g. Furthermore, weight-percent of organic carbon nearly doubles from 4 - 5% during spring storms to over 8% during fall storms, with smaller variation occurring within individual storms. Despite changes in percent organic carbon, organic carbon to mineral surface area ratios and carbon to nitrogen molar ratios remain similar within storms and across seasons.

Interconnected porosity analysis by 3D X-ray microtomography and mechanical behavior of biomimetic organic-inorganic composite materials.

PubMed

Alonso-Sierra, S; Velázquez-Castillo, R; Millán-Malo, B; Nava, R; Bucio, L; Manzano-Ramírez, A; Cid-Luna, H; Rivera-Muñoz, E M

2017-11-01

Hydroxyapatite-based materials have been used for dental and biomedical applications. They are commonly studied due to their favorable response presented when used for replacement of bone tissue. Those materials should be porous enough to allow cell penetration, internal tissue growth, vascular incursion and nutrient supply. Furthermore, their morphology should be designed to guide the growth of new bone tissue in anatomically applicable ways. In this work, the mechanical performance and 3D X-ray microtomography (X-ray μCT) study of a biomimetic, organic-inorganic composite material, based on hydroxyapatite, with physicochemical, structural, morphological and mechanical properties very similar to those of natural bone tissue is reported. Ceramic pieces in different shapes and several porous sizes were produced using a Modified Gel Casting Method. Pieces with a controlled and 3D hierarchical interconnected porous structure were molded by adding polymethylmethacrylate microspheres. Subsequently, they were subject to a thermal treatment to remove polymers and to promote a sinterization of the ceramic particles, obtaining a HAp scaffold with controlled porosity. Then, two different organic phases were used to generate an organic-inorganic composite material, so gelatin and collagen, which was extracted from bovine tail, were used. The biomimetic organic-inorganic composite material was characterized by Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, X-ray Diffraction, Fourier Transform Infrared Spectroscopy and 3D X-ray microtomography techniques. Mechanical properties were characterized in compression tests, obtaining a dramatic and synergic increment in the mechanical properties due to the chemical and physical interactions between the two phases and to the open-cell cellular behavior of the final composite material; the maximum compressive strength obtained corresponds to about 3 times higher than that reported for natural cancellous bone. The

Composite material including nanocrystals and methods of making

DOEpatents

Bawendi, Moungi G.; Sundar, Vikram C.

2010-04-06

Temperature-sensing compositions can include an inorganic material, such as a semiconductor nanocrystal. The nanocrystal can be a dependable and accurate indicator of temperature. The intensity of emission of the nanocrystal varies with temperature and can be highly sensitive to surface temperature. The nanocrystals can be processed with a binder to form a matrix, which can be varied by altering the chemical nature of the surface of the nanocrystal. A nanocrystal with a compatibilizing outer layer can be incorporated into a coating formulation and retain its temperature sensitive emissive properties.

Composite material including nanocrystals and methods of making

DOEpatents

Bawendi, Moungi G [Boston, MA; Sundar, Vikram C [New York, NY

2008-02-05

Temperature-sensing compositions can include an inorganic material, such as a semiconductor nanocrystal. The nanocrystal can be a dependable and accurate indicator of temperature. The intensity of emission of the nanocrystal varies with temperature and can be highly sensitive to surface temperature. The nanocrystals can be processed with a binder to form a matrix, which can be varied by altering the chemical nature of the surface of the nanocrystal. A nanocrystal with a compatibilizing outer layer can be incorporated into a coating formulation and retain its temperature sensitive emissive properties

Failure Study of Composite Materials by the Yeh-Stratton Criterion

NASA Technical Reports Server (NTRS)

Yeh, Hsien-Yang; Richards, W. Lance

1997-01-01

The newly developed Yeh-Stratton (Y-S) Strength Criterion was used to study the failure of composite materials with central holes and normal cracks. To evaluate the interaction parameters for the Y-S failure theory, it is necessary to perform several biaxial loading tests. However, it is indisputable that the inhomogeneous and anisotropic nature of composite materials have made their own contribution to the complication of the biaxial testing problem. To avoid the difficulties of performing many biaxial tests and still consider the effects of the interaction term in the Y-S Criterion, a simple modification of the Y-S Criterion was developed. The preliminary predictions by the modified Y-S Criterion were relatively conservative compared to the testing data. Thus, the modified Y-S Criterion could be used as a design tool. To further understand the composite failure problem, an investigation of the damage zone in front of the crack tip coupled with the Y-S Criterion is imperative.

Chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oil

PubMed Central

Mahboubi, M; Kazempour, N

2011-01-01

Background and Objectives The aim of this study was to evaluate the chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oils against different kinds of microorganisms in vitro. Material and Methods The antimicrobial activity was evaluated by micro broth dilution assay and the chemical composition of essential oils was analyzed by GC and GC/MS. Results Thymol, p-cymene, γ-terpinene and carvacrol were the main components of S. hortensis oil while thymol, γ-terpinene, and o-cymene were the major components of T. copticum oil. Two essential oils exhibited strong antimicrobial activity but the antimicrobial activity of T. copticum oil was higher than that of S. hortensis oil. Conclusion Thymol as a main component of oils plays an important role in antimicrobial activity. PMID:22530088

Chemical composition of Texas surface waters, 1949

USGS Publications Warehouse

Irelan, Burdge

1950-01-01

This report is the fifth the a series of publications by the Texas Board of Water Engineers giving chemical analyses of the surface waters in the State of Texas. The samples for which data are given were collected between October 1, 1948 and September 30, 1949. During the water year 25 daily sampling stations were maintained by the Geological Survey. Sampled were collected less frequently during the year at many other points. Quality of water records for previous years can be found in the following reports: "Chemical Composition of Texas Surface Waters, 1938-1945," by W. W. Hastings, and J. H. Rowley; "Chemical Composition of Texas Surface Waters, 1946," by W. W. Hastings and B. Irelan; "Chemical Composition of Texas Surface Waters, 1947," by B. Irelan and J. R. Avrett; "Chemical Composition of Texas Surface Waters, 1948," by B. Irelan, D. E. Weaver, and J. R. Avrett. These reports may be obtained from the Texas Board of Water Engineers and Geological Survey at Austin, Texas. Samples for chemical analysis were collected daily at or near points on streams where gaging stations are maintained for measurement of discharge. Most of the analyses were made of 10-day composites of daily samples collected for a year at each sampling point. Three composite samples were usually prepared each month by mixing together equal quantities of daily samples collected for the 1st to the 10th, from the 11th to the 20th, and during the remainder of the month. Monthly composites were made at a few stations where variation in daily conductance was small. For some streams that are subject to sudden large changes in chemical composition, composite samples were made for shorter periods on the basis of the concentration of dissolved solids as indicated by measurement of specific conductance of the daily samples. The mean discharge for the composite period is reported in second-feet. Specific conductance values are expressed as "micromhos, K x 10 at 25° C." Silica, calcium, magnesium, sodium

Relationships between botanical and chemical composition of forages: a multivariate approach to grasslands in the Western Italian Alps.

PubMed

Ravetto Enri, Simone; Renna, Manuela; Probo, Massimiliano; Lussiana, Carola; Battaglini, Luca M; Lonati, Michele; Lombardi, Giampiero

2017-03-01

Plant composition of species-rich mountain grasslands can affect the sensorial and chemical attributes of dairy and meat products, with implications for human health. A multivariate approach was used to analyse the complex relationships between vegetation characteristics (botanical composition and plant community variables) and chemical composition (proximate constituents and fatty acid profile) in mesophilic and dry vegetation ecological groups, comprising six different semi-natural grassland types in the Western Italian Alps. Mesophilic and dry grasslands were comparable in terms of phenology, biodiversity indices and proportion of botanical families. The content of total fatty acids and that of the most abundant fatty acids (alpha-linolenic, linoleic and palmitic acids) were mainly associated to nutrient-rich plant species, belonging to the mesophilic grassland ecological group. Mesophilic grasslands showed also higher values of crude protein, lower values of fibre content and they were related to higher pastoral values of vegetation compared to dry grasslands. The proximate composition and fatty acid profile appeared mainly single species dependent rather than botanical family dependent. These findings highlight that forage from mesophilic grasslands can provide higher nutritive value for ruminants and may be associated to ruminant-derived food products with a healthier fatty acid profile. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Thermal and chemical evolution in the early solar system as recorded by FUN CAIs: Part I - Petrology, mineral chemistry, and isotopic composition of Allende FUN CAI CMS-1

NASA Astrophysics Data System (ADS)

Williams, C. D.; Ushikubo, T.; Bullock, E. S.; Janney, P. E.; Hines, R. R.; Kita, N. T.; Hervig, R. L.; MacPherson, G. J.; Mendybaev, R. A.; Richter, F. M.; Wadhwa, M.

2017-03-01

Detailed petrologic, geochemical and isotopic analyses of a new FUN CAI from the Allende CV3 meteorite (designated CMS-1) indicate that it formed by extensive melting and evaporation of primitive precursor material(s). The precursor material(s) condensed in a 16O-rich region (δ17O and δ18O ∼ -49‰) of the inner solar nebula dominated by gas of solar composition at total pressures of ∼10-3-10-6 bar. Subsequent melting of the precursor material(s) was accompanied by evaporative loss of magnesium, silicon and oxygen resulting in large mass-dependent isotope fractionations in these elements (δ25Mg = 30.71-39.26‰, δ29Si = 14.98-16.65‰, and δ18O = -41.57 to -15.50‰). This evaporative loss resulted in a bulk composition similar to that of compact Type A and Type B CAIs, but very distinct from the composition of the original precursor condensate(s). Kinetic fractionation factors and the measured mass-dependent fractionation of silicon and magnesium in CMS-1 suggest that ∼80% of the silicon and ∼85% of the magnesium were lost from its precursor material(s) through evaporative processes. These results suggest that the precursor material(s) of normal and FUN CAIs condensed in similar environments, but subsequently evolved under vastly different conditions such as total gas pressure. The chemical and isotopic differences between normal and FUN CAIs could be explained by sorting of early solar system materials into distinct physical and chemical regimes, in conjunction with discrete heating events, within the protoplanetary disk.

Medium resolution spectroscopy and chemical composition of Galactic globular clusters

NASA Astrophysics Data System (ADS)

Khamidullina, D. A.; Sharina, M. E.; Shimansky, V. V.; Davoust, E.

We used integrated-light medium-resolution spectra of six Galactic globular clusters and model stellar atmospheres to carry out population synthesis and to derive chemical composition and age of the clusters. We used medium-resolution spectra of globular clusters published by Schiavon et al. (2005), as well as our long-slit observations with the 1.93 m telescope of the Haute Provence Observatory. The observed spectra were fitted to the theoretical ones interactively. As an initial approach, we used masses, radii and log g of stars in the clusters corresponding to the best fitting isochrones in the observed color-magnitude diagrams. The computed synthetic blanketed spectra of stars were summed according to the Chabrier mass function. To improve the determination of age and helium content, the shape and depth of the Balmer absorption lines was analysed. The abundances of Mg, Ca, C and several other elements were derived. A reasonable agreement with the literature data both in chemical composition and in age of the clusters is found. Our method might be useful for the development of stellar population models and for a better understanding of extragalactic star clusters.

Studies on crosslinked hydroxyapatite-polyethylene composite as a bone-analogue material

NASA Astrophysics Data System (ADS)

Smolko, E.; Romero, G.

2007-08-01

The paper examines the use of different types of polymeric matrix composites in hard-tissue replacement applications. The composite samples were prepared with hydroxyapatite (HA) powder and polyethylenes of different densities. The raw material was first compounded in the extruder and the resulting composite pre-forms were compression molded into desired plates and irradiated with different doses. Modulus of elasticity in tension, tensile strength, tensile fracture strain, elongation at break and gel content were obtained for all composites. Ceramic filler distribution was investigated under scanning electron microscopy (SEM). With HA incorporated in the samples an increase in the values of Young's Modulus, (stiffness) was observed, while elongation at break decreased with the amount of filler, showing increase of brittleness. Tensile strengths at yield and at break decreased with the filler content for LD and MDPE and stayed constant for HDPE.

Chemical precursors to non-oxide ceramics: Macro to nanoscale materials

NASA Astrophysics Data System (ADS)

Forsthoefel, Kersten M.

Non-oxide ceramics exhibit a number of important properties that make them ideal for technologically important applications (thermal and chemical stability, high strength and hardness, wear-resistance, light weight, and a range of electronic and optical properties). Unfortunately, traditional methodologies to these types of materials are limited to fairly simple shapes and complex processed forms cannot be attained through these methods. The establishment of the polymeric precursor approach has allowed for the generation of advanced materials, such as refractory non-oxide ceramics, with controlled compositions, under moderate conditions, and in processed forms. The goal of the work described in this dissertation was both to develop new processible precursors to technologically important ceramics and to achieve the formation of advanced materials in processed forms. One aspect of this research exploited previously developed preceramic precursors to boron carbide, boron nitride and silicon carbide for the generation of a wide variety of advanced materials: (1) ultra-high temperature ceramic (UHTC) structural materials composed of hafnium boride and related composite materials, (2) the quaternary borocarbide superconductors, and (3) on the nanoscale, non-oxide ceramic nanotubules. The generation of the UHTC and the quaternary borocarbide materials was achieved through a method that employs a processible polymer/metal(s) dispersion followed by subsequent pyrolyses. In the case of the UHTC, hafnium oxide, hafnium, or hafnium boride powders were dispersed in a suitable precursor to afford hafnium borides or related composite materials (HfB2/HfC, HfB2/HfN, HfB2/SiC) in high yields and purities. The quaternary borocarbide superconducting materials were produced from pyrolyses of dispersions containing appropriate stoichiometric amounts of transition metal, lanthanide metal, and the polyhexenyldecaborane polymer. Both chemical vapor deposition (CVD) based routes employing a

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

1979-01-01

Technology utilization of fiber reinforced composite materials is discussed in the areas of physical properties, and life prediction. Programs related to the Composite Aircraft Program are described in detail.

Chemical Aging of Environmentally Friendly Cleaners

NASA Technical Reports Server (NTRS)

Biegert, L. L.; Evans, K. B.; Olsen, B. D.; Weber, B. L.

2001-01-01

Use of cleaners in the manufacturing area demands bottles that will hold a sufficient amount of material and allow for easy and controlled dispensing by the operator without contamination or material leaching from the bottle. The manufacturing storage conditions are also a factor that may affect cleaner chemical integrity and its potential to leave a residue on the part. A variety of squeeze bottles stored in mild (72 F, 10% R.H., dark) and harsh (105 F, 50% R.H., fluorescent lighting) conditions were evaluated to determine the effect of environment and bottle exposure on ozone depleting chemicals (ODC) cleaners chemical composition. Low Density Polyethylene (LDPE) bottles were found to be quite permeable to all the cleaners evaluated in this study indicating this bottle type should not be used in the manufacturing area. Fluorinated Polyethylene (FLPE) bottles showed little cleaner loss and change in cleaner chemical composition over time suggesting these bottles would be acceptable for use. Chemical analysis indicates limonene containing cleaners show increased non-volatile residue (NVR) content with storage under harsh conditions. Some cleaners use BHT (butylated hydroxytoluene) as stabilizer and to protect against limonene oxidation. Under harsh conditions, BHT was quickly depleted resulting in higher NVR levels.

Correlation between thermal behavior of clays and their chemical and mineralogical composition: a review

NASA Astrophysics Data System (ADS)

Dwi Yanti, Evi; Pratiwi, I.

2018-02-01

Clay's abundance has been widely used as industrial raw materials, especially ceramic and tile industries. Utilization of these minerals needs a thermal process for producing ceramic products. Two studies conducted by Septawander et al. and Chin C et al., showed the relationship between thermal behavior of clays and their chemical and mineralogical composition. Clays are characterized by XRD analysis and thermal analysis, ranging from 1100°C to 1200°C room temperature. Specimen of raw materials of clay which is used for the thermal treatment is taken from different geological conditions and formation. In raw material, Quartz is almost present in all samples. Halloysite, montmorillonite, and feldspar are present in Tanjung Morawa raw clay. KC and MC similar kaolinite and illite are present in the samples. The research illustrates the interrelationships of clay minerals and chemical composition with their heat behavior. As the temperature of combustion increases, the sample reduces a significant weight. The minerals which have undergone a transformation phase became mullite, cristobalite or illite and quartz. Under SEM analysis, the microstructures of the samples showed irregularity in shape; changes occurred due the increase of heat.