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Sample records for unburned mixture composition

  1. Burned gas and unburned mixture composition prediction in biodiesel-fuelled compression igniton engine

    International Nuclear Information System (INIS)

    Chuepeng, S.; Komintarachati, C.

    2009-01-01

    A prediction of burned gas and unburned mixture composition from a variety of methyl ester based bio diesel combustion in compression ignition engine, in comparison with conventional diesel fuel is presented. A free-energy minimisation scheme was used to determine mixture composition. Firstly, effects of bio diesel type were studied without exhaust gas recirculation (EGR). The combustion of the higher hydrogen-to-carbon molar ratio (H/C) bio diesel resulted in lower carbon dioxide and oxygen emissions but higher water vapour in the exhaust gases, compared to those of lower H/C ratios. At the same results also show that relative air-to-fuel ratio, that bio diesel combustion gases contain a higher amount of water vapour and a higher level of carbon dioxide compared to those of diesel. Secondly, influences of EGR (burned gas fraction) addition to bio diesel-fuelled engine on unburned mixture were simulated. For both diesel and bio diesel, the increased burned gas fraction addition to the fresh charge increased carbon dioxide and water vapour emissions while lowering oxygen content, especially for the bio diesel case. The prediction was compared with experimental results from literatures; good agreement was found. This can be considered to be a means for explaining some phenomenon occurring in bio diesel-fuelled engines. (author)

  2. Temperature and air-fuel ratio dependent specific heat ratio functions for lean burned and unburned mixture

    International Nuclear Information System (INIS)

    Ceviz, M.A.; Kaymaz, I.

    2005-01-01

    The most important thermodynamic property used in heat release calculations for engines is the specific heat ratio. The functions proposed in the literature for the specific heat ratio are temperature dependent and apply at or near stoichiometric air-fuel ratios. However, the specific heat ratio is also influenced by the gas composition in the engine cylinder and especially becomes important for lean combustion engines. In this study, temperature and air-fuel ratio dependent specific heat ratio functions were derived to minimize the error by using an equilibrium combustion model for burned and unburned mixtures separately. After the error analysis between the equilibrium combustion model and the derived functions is presented, the results of the global specific heat ratio function, as varying with mass fraction burned, were compared with the proposed functions in the literature. The results of the study showed that the derived functions are more feasible at lean operating conditions of a spark ignition engine

  3. Composition measurements of binary mixture droplets by rainbow refractometry.

    Science.gov (United States)

    Wilms, J; Weigand, B

    2007-04-10

    So far, refractive index measurements by rainbow refractometry have been used to determine the temperature of single droplets and ensembles of droplets. Rainbow refractometry is, for the first time, to the best of our knowledge, applied to measure composition histories of evaporating, binary mixture droplets. An evaluation method is presented that makes use of Airy theory and the simultaneous size measurement by Mie scattering imaging. The method further includes an empirical correction function for a certain diameter and refractive index range. The measurement uncertainty was investigated by numerical simulations with Lorenz-Mie theory. For the experiments, an optical levitation setup was used allowing for long measurement periods. Temperature measurements of single-component droplets at different temperature levels are shown to demonstrate the accuracy of rainbow refractometry. Measurements of size and composition histories of binary mixture droplets are presented for two different mixtures. Experimental results show good agreement with numerical results using a rapid-mixing model.

  4. Composition measurements of binary mixture droplets by rainbow refractometry

    International Nuclear Information System (INIS)

    Wilms, J.; Weigand, B.

    2007-01-01

    So far, refractive index measurements by rainbow refractometry have been used to determine the temperature of single droplets and ensembles of droplets. Rainbow refractometry is, for the first time, to the best of our knowledge, applied to measure composition histories of evaporating, binary mixture droplets. An evaluation method is presented that makes use of Airy theory and the simultaneous size measurement by Mie scattering imaging. The method further includes an empirical correction function for a certain diameter and refractive index range. The measurement uncertainty was investigated by numerical simulations with Lorenz-Mie theory. For the experiments, an optical levitation setup was used allowing for long measurement periods. Temperature measurements of single-component droplets at different temperature levels are shown to demonstrate the accuracy of rainbow refractometry. Measurements of size and composition histories of binary mixture droplets are presented for two different mixtures. Experimental results show good agreement with numerical results using a rapid-mixing model

  5. Real-time composition determination of gas mixtures

    NARCIS (Netherlands)

    Lötters, Joost Conrad; van der Wouden, E.J.; Groenesteijn, Jarno; Sparreboom, Wouter; Lammerink, Theodorus S.J.; Wiegerink, Remco J.

    2014-01-01

    We have designed and implemented an analytical calculation model with which we can real-time determine the composition of gas mixtures. The model is based upon a multi-parameter flow measurement system, consisting of a Coriolis and thermal flow sensor, a density meter and a pressure sensor. The

  6. Nutrient composition of Dacryodes edulis seed and seed coat mixture

    Directory of Open Access Journals (Sweden)

    C.U. OGUNKA-NNOKA

    2017-07-01

    Full Text Available This study investigated the nutrient composition of D. edulis seed and seed coat mixture. Qualitative and quantitative phytochemicals, proximate, and vitamin compositions were evaluated using standard methods. Saponins were very high, alkaloids, flavonoids, and tannins were high, while terpenoids were low, and glycosides, aldehydes, and steroids were absent. The quantitative phytochemical determination followed the order; saponin > kaempferol > rutin > catechin > tannin > sapogenin > lunamarine > phenol > ribalinidine > anthocyanin > oxalate > phytate. For the proximate composition, carbohydrates had the highest concentration, followed by lipids and fibre, while, protein concentration was the lowest. Vitamin E (5.42 mg/100g, vitamin C (3.24 mg/100g, and vitamin A (2.84 mg/100g were the highest occurring constituent vitamins while vitamin B12 (0.035 mg/100g and vitamin B2 (0.075 mg/100g were the least occurring vitamins. This study has shown the rich phytochemical composition of D. edulis seed and seed coat mixture while showing deficiencies in proteins, distinct vitamins, and ash contents.

  7. Composition inversion in mixtures of binary colloids and polymer

    Science.gov (United States)

    Zhang, Isla; Pinchaipat, Rattachai; Wilding, Nigel B.; Faers, Malcolm A.; Bartlett, Paul; Evans, Robert; Royall, C. Patrick

    2018-05-01

    Understanding the phase behaviour of mixtures continues to pose challenges, even for systems that might be considered "simple." Here, we consider a very simple mixture of two colloidal and one non-adsorbing polymer species, which can be simplified even further to a size-asymmetrical binary mixture, in which the effective colloid-colloid interactions depend on the polymer concentration. We show that this basic system exhibits surprisingly rich phase behaviour. In particular, we enquire whether such a system features only a liquid-vapor phase separation (as in one-component colloid-polymer mixtures) or whether, additionally, liquid-liquid demixing of two colloidal phases can occur. Particle-resolved experiments show demixing-like behaviour, but when combined with bespoke Monte Carlo simulations, this proves illusory, and we reveal that only a single liquid-vapor transition occurs. Progressive migration of the small particles to the liquid phase as the polymer concentration increases gives rise to composition inversion—a maximum in the large particle concentration in the liquid phase. Close to criticality, the density fluctuations are found to be dominated by the larger colloids.

  8. What is unburned carbon?; Vad aer ofoerbraent?

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem, Henrik [AaF-Process AB, Stockholm (Sweden); Suer, Pascal [Swedish Geotechnical Inst., Linkoeping (Sweden)

    2006-01-15

    Different methods to determine unburned carbon in an ash yield different results, which raises the question of what actually is unburned. Using knowledge on the chemistry of ashes, one can identify which processes that contribute to the results from a method of analysis, but it is not possible to quantify these contributions. The project that is reported here aimed at clarifying what the results from the different methods mean using practical examples. Approximately twenty ash samples have been collected and their content of unburned carbon determined using loss on ignition at different temperatures, instrumental analysis of TOC and wet oxidation (the so-called colorimetric method). In order to identify the processes contributing to the results the samples have been investigated using a thermobalance instrumented with DTA and mass spectrometry for the species released when the samples are heated in air. The results can be grouped according to the type of ash: bottom ash, ESP ashes or baghouse filter ashes. They each have their specific fingerprints. Although the same processes contribute to the LOI, the proportions differ. In the case of bottom ashes, LOI and TOC yield results close to each other. A large part of the LOI is TOC, but not all. TOC is dominated by charred fuel (elementar carbon) and organic is a minor part. In the case of fly ashes, LOI and TOC yield results that differ from each other. As for bottom ashes, a large part of the LOI at 550 deg C is TOC, dominated by char or elemental carbon. The LOI at higher temperatures is often at least double and includes much more. Igniting ESP and baghouse filter ash samples at ca 1000 deg C leads to losses of volatile salts, e g chlorides. The colorimetric method takes some of the TOC, not only organic matter. The TOC methods should be preferred to it. The LOI methods yield values that are generally too high. As they are easy to implement their use will be continued. We recommend that: Ash is not ignited at

  9. Productivity, botanical composition, and nutritive value of commercial pasture mixtures

    Science.gov (United States)

    Pastures in the northeastern USA often are planted to mixtures of grasses and legumes. There is limited public sector information on the performance of commercial forage mixtures. We evaluated a range of commercial pasture mixtures to determine if the number of species in a mixture affected yield an...

  10. Optimization of the composition of the powdered cereal sprouts mixtures

    Directory of Open Access Journals (Sweden)

    Tumbas-Šaponjac Vesna T.

    2016-01-01

    Full Text Available Sprouts of cereals have received significant attention as functional food due to their nutritional and functional value. Consumption of sprouts has become increasingly popular among people interested in improving and maintaining their health status by changing dietary habits. Cereal grains contain several classes of phytochemicals, i.e. phenolics, chlorophylls, and carotenoids. However, their nutritional and chemical profile is altered and improved during germination. The purpose of this study was to find the best ratio of the powdered wheat (WS, oat (OS and barley (BS sprouts for designing the cereal sprout mixture (CSM with the highest total phenolic content (TPh and antioxidant capacity (AC, using Simplex-Centroid experimental design and response surface methodology (RSM. Single- and multi-response optimizations showed that OS did not contribute to TPh or AC values of CSM and, therefore, was not included in any of the compositions of the optimized CSM. Single-response optimizations showed that the highest TPh was found for CSM containing 82% BS and 18% WS, while the best AC was found for pure BS. The predicted ratio of cereal sprout powders in CSM obtained by multi-response optimization was: 96% BS and 4% WS. This mixture possessed the highest predicted TPh and AC (372.32 mg GAE/100 g, 549.99 μmol TE/100 g, respectively, which was confirmed to be in accordance with the experimental values. Based on the results obtained in this study, a designed CSM is proposed as a convenient ingredient of functional food products, dietary supplements and nutraceuticals.

  11. A predictive model of natural gas mixture combustion in internal combustion engines

    Directory of Open Access Journals (Sweden)

    Henry Espinoza

    2007-05-01

    Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

  12. Unburned carbon in combustion residues from mainly solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem H; Lind B; Lagerkvist A

    2012-02-15

    Unburned carbon in 21 combustion residues from solid biofuels is investigated using several methods of analysis (a.o. LOI and TOC), as well as micro-Raman spectroscopy. The results are used to discuss the distribution of unburned carbon in the residues from the different combustion plants and its nature (organic or elemental). The consequences of the elemental nature of carbon for environmental properties of the residue are noted

  13. Mixture

    Directory of Open Access Journals (Sweden)

    Silva-Aguilar Martín

    2011-01-01

    Full Text Available Metals are ubiquitous pollutants present as mixtures. In particular, mixture of arsenic-cadmium-lead is among the leading toxic agents detected in the environment. These metals have carcinogenic and cell-transforming potential. In this study, we used a two step cell transformation model, to determine the role of oxidative stress in transformation induced by a mixture of arsenic-cadmium-lead. Oxidative damage and antioxidant response were determined. Metal mixture treatment induces the increase of damage markers and the antioxidant response. Loss of cell viability and increased transforming potential were observed during the promotion phase. This finding correlated significantly with generation of reactive oxygen species. Cotreatment with N-acetyl-cysteine induces effect on the transforming capacity; while a diminution was found in initiation, in promotion phase a total block of the transforming capacity was observed. Our results suggest that oxidative stress generated by metal mixture plays an important role only in promotion phase promoting transforming capacity.

  14. SGC Tests for Influence of Material Composition on Compaction Characteristic of Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Qun Chen

    2013-01-01

    Full Text Available Compaction characteristic of the surface layer asphalt mixture (13-type gradation mixture was studied using Superpave gyratory compactor (SGC simulative compaction tests. Based on analysis of densification curve of gyratory compaction, influence rules of the contents of mineral aggregates of all sizes and asphalt on compaction characteristic of asphalt mixtures were obtained. SGC Tests show that, for the mixture with a bigger content of asphalt, its density increases faster, that there is an optimal amount of fine aggregates for optimal compaction and that an appropriate amount of mineral powder will improve workability of mixtures, but overmuch mineral powder will make mixtures dry and hard. Conclusions based on SGC tests can provide basis for how to adjust material composition for improving compaction performance of asphalt mixtures, and for the designed asphalt mixture, its compaction performance can be predicted through these conclusions, which also contributes to the choice of compaction schemes.

  15. Composition dependent non-ideality in aqueous binary mixtures as ...

    Indian Academy of Sciences (India)

    understanding in the molecular level. The origin of the .... analysis of inherent structures (IS) of binary mixture in ... liminary molecular dynamics simulation to equilibrate the system at ..... the clusters gradually increase as the concentration of.

  16. Methods and compositions for removing carbon dioxide from a gaseous mixture

    Science.gov (United States)

    Li, Jing; Wu, Haohan

    2014-06-24

    Provided is a method for adsorbing or separating carbon dioxide from a mixture of gases by passing the gas mixture through a porous three-dimensional polymeric coordination compound having a plurality of layers of two-dimensional arrays of repeating structural units, which results in a lower carbon dioxide content in the gas mixture. Thus, this invention provides useful compositions and methods for removal of greenhouse gases, in particular CO.sub.2, from industrial flue gases or from the atmosphere.

  17. Influence of the composition of radionuclide mixtures on the maximum permissible concentration

    International Nuclear Information System (INIS)

    Schillinger, K.; Schuricht, V.

    1975-08-01

    By dividing radionuclides according to their formation mechanisms it is possible to assess the influence of separate partial mixtures on the maximum permissible concentration (MPC) of the total mixture without knowing exactly their contribution to the total activity. Calculations showed that the MPC of a total mixture of unsoluble radionuclides, which may occur in all fields of peaceful uses of nuclear energy, depends on the gastrointestinal tract as the critical organ and on the composition of the fission product mixture. The influence of fractionation on the MPC can be reglected in such a case, whereas in case of soluble radionuclides this is not possible

  18. Composition dependent non-ideality in aqueous binary mixtures as ...

    Indian Academy of Sciences (India)

    SBBM) where two constituents dislike each other, yet remain macroscopically homogeneous at intermediate to high temperatures. Interestingly, we find that the origin of strong composition dependent non-ideal behaviour lies in its phase ...

  19. Purification of iodine-containing mixtures and compositions useful therefor

    International Nuclear Information System (INIS)

    Cobb, R.L.

    1987-01-01

    This patent describes a process for the preparation by distillation of essentially colorless hydrocarbon product substantially free of color-forming impurities, which process comprises: (a) adding 0.02 to 0.10 wt% of a metal, M, to a solution comprising: (i) a hydrocarbon product having 8-30 carbon atoms, and (ii) at least one color-forming impurity selected from the group consisting of: I/sub 2/, and R-I, wherein R is H or an organic radical having 1-30 carbon atoms, inclusive. The color-forming impurity and the metal interact under distillation conditions form a complex, MI/sub n/, where n is equal to the valence of the metal M, and the complex MI/sub n/ is non-volatile and essentially non-decomposable under distillation conditions; (b) subjecting the resulting mixture to distillation conditions; and (c) recovering essentially colorless hydrocarbon product as the overhead fraction from the distillation

  20. Recreating the seawater mixture composition of HOCs in toxicity tests with Artemia franciscana by passive dosing

    Energy Technology Data Exchange (ETDEWEB)

    Rojo-Nieto, E., E-mail: elisa.rojo@uca.es [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Smith, K.E.C. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark); Perales, J.A. [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Mayer, P. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark)

    2012-09-15

    The toxicity testing of hydrophobic organic compounds (HOCs) in aquatic media is generally challenging, and this is even more problematic for mixtures. The hydrophobic properties of these compounds make them difficult to dissolve, and subsequently to maintain constant exposure concentrations. Evaporative and sorptive losses are highly compound-specific, which can alter not only total concentrations, but also the proportions between the compounds in the mixture. Therefore, the general aim of this study was to explore the potential of passive dosing for testing the toxicity of a PAH mixture that recreates the mixture composition found in seawater from a coastal area of Spain, the Bay of Algeciras. First, solvent spiking and passive dosing were compared for their suitability to determine the acute toxicity to Artemia franciscana nauplii of several PAHs at their respective solubility limits. Second, passive dosing was applied to recreate the seawater mixture composition of PAHs measured in a Spanish monitoring program, to test the toxicity of this mixture at different levels. HPLC analysis was used to confirm the reproducibility of the dissolved exposure concentrations for the individual PAHs and mixtures. This study shows that passive dosing has some important benefits in comparison with solvent spiking for testing HOCs in aquatic media. These include maintaining constant exposure concentrations, leading to higher reproducibility and a relative increase in toxicity. Passive dosing is also able to faithfully reproduce real mixtures of HOCs such as PAHs, in toxicity tests, reproducing both the levels and proportions of the different compounds. This provides a useful approach for studying the toxicity of environmental mixtures of HOCs, both with a view to investigating their toxicity but also for determining safety factors before such mixtures result in detrimental effects.

  1. Multi Parameter Flow Meter for On-Line Measurement of Gas Mixture Composition

    Directory of Open Access Journals (Sweden)

    Egbert van der Wouden

    2015-04-01

    Full Text Available In this paper we describe the development of a system and model to analyze the composition of gas mixtures up to four components. The system consists of a Coriolis mass flow sensor, density, pressure and thermal flow sensor. With this system it is possible to measure the viscosity, density, heat capacity and flow rate of the medium. In a next step the composition can be analyzed if the constituents of the mixture are known. This makes the approach universally applicable to all gasses as long as the number of components does not exceed the number of measured properties and as long as the properties are measured with a sufficient accuracy. We present measurements with binary and ternary gas mixtures, on compositions that range over an order of magnitude in value for the physical properties. Two platforms for analyses are presented. The first platform consists of sensors realized with MEMS fabrication technology. This approach allows for a system with a high level of integration. With this system we demonstrate a proof of principle for the analyses of binary mixtures with an accuracy of 10%. In the second platform we utilize more mature steel sensor technology to demonstrate the potential of this approach. We show that with this technique, binary mixtures can be measured within 1% and ternary gas mixtures within 3%.

  2. Simulations of Flame Acceleration and DDT in Mixture Composition Gradients

    Science.gov (United States)

    Zheng, Weilin; Kaplan, Carolyn; Houim, Ryan; Oran, Elaine

    2017-11-01

    Unsteady, multidimensional, fully compressible numerical simulations of methane-air in an obstructed channel with spatial gradients in equivalence ratios have been carried to determine the effects of the gradients on flame acceleration and transition to detonation. Results for gradients perpendicular to the propagation direction were considered here. A calibrated, optimized chemical-diffusive model that reproduces correct flame and detonation properties for methane-air over a range of equivalence ratios was derived from a combination of a genetic algorithm with a Nelder-Mead optimization scheme. Inhomogeneous mixtures of methane-air resulted in slower flame acceleration and longer distance to DDT. Detonations were more likely to decouple into a flame and a shock under sharper concentration gradients. Detailed analyses of temperature and equivalence ratio illustrated that vertical gradients can greatly affect the formation of hot spots that initiate detonation by changing the strength of leading shock wave and local equivalence ratio near the base of obstacles. This work is supported by the Alpha Foundation (Grant No. AFC215-20).

  3. Optimization of composite flour biscuits by mixture response surface methodology.

    Science.gov (United States)

    Okpala, Laura C; Okoli, Eric C

    2013-08-01

    Biscuits were produced from blends of pigeon pea, sorghum and cocoyam flours. The study was carried out using mixture response surface methodology as the optimization technique. Using the simplex centroid design, 10 formulations were obtained. Protein and sensory quality of the biscuits were analyzed. The sensory attributes studied were appearance, taste, texture, crispness and general acceptability, while the protein quality indices were biological value and net protein utilization. The results showed that while the addition of pigeon pea improved the protein quality, its addition resulted in reduced sensory ratings for all the sensory attributes with the exception of appearance. Some of the biscuits had sensory ratings, which were not significantly different (p > 0.05) from biscuits made with wheat. Rat feeding experiments indicated that the biological value and net protein utilization values obtained for most of the biscuits were above minimum recommended values. Optimization suggested biscuits containing 75.30% sorghum, 0% pigeon pea and 24.70% cocoyam flours as the best proportion of these components. This sample received good scores for the sensory attributes.

  4. Kinetic modelling and mechanism of dye adsorption on unburned carbon

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.B.; Li, H.T. [Curtin University of Technology, Perth, WA (Australia). Dept. of Chemical Engineering

    2007-07-01

    Textile dyeing processes are among the most environmentally unfriendly industrial processes by producing coloured wastewaters. The adsorption method using unburned carbon from coal combustion residue was studied for the decolourisation of typical acidic and basic dyes. It was discovered that the unburned carbon showed high adsorption capacity at 1.97 x 10{sup -4} and 5.27 x 10{sup -4} mol/g for Basic Violet 3 and Acid Black 1, respectively. The solution pH, particle size and temperature significantly influenced the adsorption capacity. Higher solution pH favoured the adsorption of basic dye while reduced the adsorption of acid dye. The adsorption of dye increased with increasing temperature but decreased with increasing particle size. Sorption kinetic data indicated that the adsorption kinetics followed the pseudo-second-order model. The adsorption mechanism consisted of two processes, external diffusion and intraparticle diffusion, and the external diffusion was the dominating process.

  5. Systematic study of RPC performances in polluted or varying gas mixtures compositions: an online monitor system for the RPC gas mixture at LHC

    CERN Document Server

    Capeans, M; Mandelli, B

    2012-01-01

    The importance of the correct gas mixture for the Resistive Plate Chamber (RPC) detector systems is fundamental for their correct and safe operation. A small change in the percentages of the gas mixture components can alter the RPC performance and this will rebound on the data quality in the ALICE, ATLAS and CMS experiments at CERN. A constant monitoring of the gas mixture injected in the RPCs would avoid such kind of problems. A systematic study has been performed to understand RPC performances with several gas mixture compositions and in the presence of common gas impurities. The systematic analysis of several RPC performance parameters in different gas mixtures allows the rapid identification of any variation in the RPC gas mixture. A set-up for the online monitoring of the RPC gas mixture in the LHC gas systems is also proposed.

  6. Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method.

    Science.gov (United States)

    Selvaraju, R; Raja, A; Thiruppathi, G

    2013-10-01

    In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm(-1) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Composite Preparation of Wood Dust-Polyester-Coconut Choir Fiber Mixture for Particle Board

    International Nuclear Information System (INIS)

    Danu, Sugiarto; Darsono; Padmono; Betty, Angesti

    2002-01-01

    Experiment on the use of γ-ray of Co 60 radiation has been used for curing of composite which made of wood dust, unsaturated polyester resin and coconut coir mixture. Composite was prepared by mixing of wood dust, polyester and coconut coir at a various mixture composition. Concentration of polyesters were 50, 55 and 60 % by weight based on saw dust and polyester mixture. Irradiation was conducted using 27,6 kCi acti vity Co 60 at a dose rate of 5 kGy/hrs and dose of 8, 10 and 12 kGy. Composite was also prepared conventionally by using peroxide catalyst. Parameters observed were density, pencil hardness and compression strength Experimental results showed that optimum condition wus achieved at irradiation dose of 12 kGy, polyester concentration of 60 % and coconut coir fiber of 4 %. In this condition, the density, hardness and compression strength were 1,115 g/cm 3, 5 Hand 6,815 kN/cm2 respectively. Density, hardness of composite prepared by radiation were almost the same whereas the compression strength was higher than that of composite prepared by conventional method

  8. Fully integrated microfluidic measurement system for real-time determination of gas and liquid mixtures composition

    NARCIS (Netherlands)

    Lötters, Joost Conrad; Groenesteijn, Jarno; van der Wouden, E.J.; Sparreboom, Wouter; Lammerink, Theodorus S.J.; Wiegerink, Remco J.

    2015-01-01

    We have designed and realised a fully integrated microfluidic measurement system for real-time determination of both flow rate and composition of gas- and liquid mixtures. The system comprises relative permittivity sensors, pressure sensors, a Coriolis flow and density sensor, a thermal flow sensor

  9. Differential Diptera succession patterns onto partially burned and unburned pig carrion in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    J Oliveira-Costa

    Full Text Available In the present contribution we compared the entomological succession pattern of a burned carcass with that of an unburned one. For that, we used domestic pig carcasses and focused on Calliphoridae, Muscidae and Sarcophagidae flies, because they are the ones most commonly used in Postmortem Interval estimates. Adult and immature flies were collected daily. A total of 27 species and 2,498 specimens were collected, 1,295 specimens of 26 species from the partially burned carcass and 1,203 specimens of 22 species from the control carcass (unburned. The species composition in the two samples differed, and the results of the similarity measures were 0.875 by Sorensen and 0.756 by Bray-Curtis index. The results obtained for both carcasses also differ with respect to the decomposition process, indicating that the post mortem interval would be underestimated if the entomological succession pattern observed for a carcass under normal conditions was applied to a carbonized carcass.

  10. Improvement of composition of core sand and molding sand mixtures for power machine building castings

    International Nuclear Information System (INIS)

    Velikanov, G.F.; Primak, I.N.; Brechko, A.A.

    1982-01-01

    Considered is a problem of development and improvement of mixtures, as well as of antisticking coatings with the given parameters providing production of castings of the necessary quality. Requirements to properties of mixtures and antisticking coatings are formulated proceeding from the conditions of guaranteed production of qualitative steel castings with mass from 0.5 up to 20t and wall thickness from 60 up to 200 mm. Formation of film structure of binding compositions is studied, their marginal contact angle and surface tension are determined. In the result of work carried out on improvement of core sand and molding sand mixtures the labour productivity during the production of core and moldings has been increased in 20-25% in average, the quality has also been improved [ru

  11. The discussion of composition shift in organic Rankine cycle using zeotropic mixtures

    International Nuclear Information System (INIS)

    Zhou, Yaodong; Zhang, Fengyuan; Yu, Lijun

    2017-01-01

    Highlights: • The forming reasons of composition shift are well illuminated. • The influences of composition shift on ORC system are presented. • The influence factors of composition shift are well discussed. • The inner relation between temperature glide and composition shift is revealed. - Abstract: Zeotropic mixtures have been important candidates for working fluids in the organic Rankine cycle (ORC) because of the temperature glide characteristic. “Composition shift” is a widespread phenomenon for zeotropic mixtures’ application in thermodynamic systems and certainly needs to be considered in ORC. In this paper, the evaporator, condenser, expander and pump models are respectively developed and then the circulating composition is calculated. Based on that, the forming reasons of “composition shift” are well illuminated. The influences of composition shift on the system net power output and heat transfer process are presented and analysed. The influence factors including pressure, two-phase zone area, total charge mass and velocity difference between liquid and vapor phase are also carefully discussed. Besides, the inner relation between temperature glide and composition shift is also revealed at last. The results showed that the optimal charge concentration of the low boiling point component in practice should be a bit lower than the optimal concentration without considering composition shift. Besides, the local composition shift characteristic will affect the heat transfer process by altering the temperature along the heat exchanger. Reducing the two-phase zone area, increasing the total charge mass, increasing the evaporation pressure and reducing the slip ratio can mitigate the effect of composition shift. The simulation also reveals that the magnitudes of temperature glide and composition shift show a good linear relation by just altering the charge composition.

  12. Sintering by infiltration of loose mixture of powders, a method for metal matrix composite elaboration

    International Nuclear Information System (INIS)

    Constantinescu, V.; Orban, R.; Colan, H.

    1993-01-01

    Starting from the observation that Sintering by Infiltration of Loose Mixture of Powders confers large possibilities for both complex shaped and of large dimensions Particulate Reinforced Metal Matrix Composite components elaboration, its mechanism comparative with those of the classical melt infiltration was investigated. Appropriate measures in order to prevent an excessive hydrostatic flow of the melt and, consequently, reinforcement particle dispersion, as well as to promote wetting in both infiltration and liquid phase sintering stages of the process were established as necessary. Some experimental results in the method application to the fusion tungsten carbide and diamond reinforced metal matrix composite elaboration are, also, presented. (orig.)

  13. Diesel/CNG Mixture Autoignition Control Using Fuel Composition and Injection Gap

    Directory of Open Access Journals (Sweden)

    Firmansyah

    2017-10-01

    Full Text Available Combustion phasing is the main obstacle to the development of controlled auto-ignition based (CAI engines to achieve low emissions and low fuel consumption operation. Fuel combinations with substantial differences in reactivity, such as diesel/compressed natural gas (CNG, show desirable combustion outputs and demonstrate great possibility in controlling the combustion. This paper discusses a control method for diesel/CNG mixture combustion with a variation of fuel composition and fuel stratification levels. The experiments were carried out in a constant volume combustion chamber with both fuels directly injected into the chamber. The mixture composition was varied from 0 to 100% CNG/diesel at lambda 1 while the fuel stratification level was controlled by the injection phasing between the two fuels, with gaps between injections ranging from 0 to 20 ms. The results demonstrated the suppressing effect of CNG on the diesel combustion, especially at the early combustion stages. However, CNG significantly enhanced the combustion performance of the diesel in the later stages. Injection gaps, on the other hand, showed particular behavior depending on mixture composition. Injection gaps show less effect on combustion phasing but a significant effect on the combustion output for higher diesel percentage (≥70%, while it is contradictive for lower diesel percentage (<70%.

  14. Variable composition hydrogen/natural gas mixtures for increased engine efficiency and decreased emissions

    Energy Technology Data Exchange (ETDEWEB)

    Sierens, R.; Rosseel, E.

    2000-01-01

    It is well known that adding hydrogen to natural gas extends the lean limit of combustion and that in this way extremely low emission levels can be obtained: even the equivalent zero emission vehicle (EZEV) requirements can be reached. The emissions reduction is especially important at light engine loads. In this paper results are presented for a GM V8 engine. Natural gas, pure hydrogen and different blends of these two fuels have been tested. The fuel supply system used provides natural gas/hydrogen mixtures in variable proportion, regulated independently of the engine operating condition. The influence of the fuel composition on the engine operating characteristics and exhaust emissions has been examined, mainly but not exclusively for 10 and 20% hydrogen addition. At least 10% hydrogen addition is necessary for a significant improvement in efficiency. Due to the conflicting requirements for low hydrocarbons and low NO{sub x} determining the optimum hythane composition is not straight-forward. For hythane mixtures with a high hydrogen fraction, it is found that a hydrogen content of 80% or less guarantees safe engine operation (no backfire nor knock), whatever the air excess factor. It is shown that to obtain maximum engine efficiency for the whole load range while taking low exhaust emissions into account, the mixture composition should be varied with respect to engine load.

  15. UNBURNED MATERIAL IN THE EJECTA OF TYPE Ia SUPERNOVAE

    International Nuclear Information System (INIS)

    Folatelli, Gastón; Tanaka, Masaomi; Maeda, Keiichi; Nomoto, Ken'ichi; Phillips, M. M.; Morrell, Nidia; Campillay, Abdo; González, Sergio; Roth, Miguel; Stritzinger, Maximilian; Burns, Christopher R.; Freedman, W. L.; Madore, Barry F; Persson, S. E.; Hamuy, Mario; Mazzali, Paolo; Boldt, Luis; Contreras, Carlos; Salgado, Francisco; Suntzeff, Nicholas B.

    2012-01-01

    The presence of unburned material in the ejecta of normal Type Ia supernovae (SNe Ia) is investigated using early-time spectroscopy obtained by the Carnegie Supernova Project. The tell-tale signature of pristine material from a C+O white dwarf progenitor star is the presence of carbon, as oxygen is also a product of carbon burning. The most prominent carbon lines in optical spectra of SNe Ia are expected to arise from C II. We find that at least 30% of the objects in the sample show an absorption at ≈6300 Å which is attributed to C II λ6580. An alternative identification of this absorption as Hα is considered to be unlikely. These findings imply a larger incidence of carbon in SNe Ia ejecta than previously noted. We show how observational biases and physical conditions may hide the presence of weak C II lines, and account for the scarcity of previous carbon detections in the literature. This relatively large frequency of carbon detections has crucial implications on our understanding of the explosive process. Furthermore, the identification of the 6300 Å absorptions as carbon would imply that unburned material is present at very low expansion velocities, merely ≈1000 km s –1 above the bulk of Si II. Based on spectral modeling, it is found that the detections are consistent with a mass of carbon of 10 –3 to 10 –2 M ☉ . The presence of this material so deep in the ejecta would imply substantial mixing, which may be related to asymmetries of the flame propagation. Another possible explanation for the carbon absorptions may be the existence of clumps of unburned material along the line of sight. However, the uniformity of the relation between C II and Si II velocities is not consistent with such small-scale asymmetries. The spectroscopic and photometric properties of SNe Ia with and without carbon signatures are compared. A trend toward bluer color and lower luminosity at maximum light is found for objects which show carbon.

  16. UNBURNED MATERIAL IN THE EJECTA OF TYPE Ia SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Folatelli, Gaston; Tanaka, Masaomi; Maeda, Keiichi; Nomoto, Ken' ichi [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Phillips, M. M.; Morrell, Nidia; Campillay, Abdo; Gonzalez, Sergio; Roth, Miguel [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Stritzinger, Maximilian [The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, 10691 Stockholm (Sweden); Burns, Christopher R.; Freedman, W. L.; Madore, Barry F; Persson, S. E. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Hamuy, Mario [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Mazzali, Paolo [Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany); Boldt, Luis [Argelander Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, D-53111 Bonn (Germany); Contreras, Carlos [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Victoria 3122 (Australia); Salgado, Francisco [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Suntzeff, Nicholas B., E-mail: gaston.folatelli@ipmu.jp [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)

    2012-01-20

    The presence of unburned material in the ejecta of normal Type Ia supernovae (SNe Ia) is investigated using early-time spectroscopy obtained by the Carnegie Supernova Project. The tell-tale signature of pristine material from a C+O white dwarf progenitor star is the presence of carbon, as oxygen is also a product of carbon burning. The most prominent carbon lines in optical spectra of SNe Ia are expected to arise from C II. We find that at least 30% of the objects in the sample show an absorption at Almost-Equal-To 6300 A which is attributed to C II {lambda}6580. An alternative identification of this absorption as H{alpha} is considered to be unlikely. These findings imply a larger incidence of carbon in SNe Ia ejecta than previously noted. We show how observational biases and physical conditions may hide the presence of weak C II lines, and account for the scarcity of previous carbon detections in the literature. This relatively large frequency of carbon detections has crucial implications on our understanding of the explosive process. Furthermore, the identification of the 6300 A absorptions as carbon would imply that unburned material is present at very low expansion velocities, merely Almost-Equal-To 1000 km s{sup -1} above the bulk of Si II. Based on spectral modeling, it is found that the detections are consistent with a mass of carbon of 10{sup -3} to 10{sup -2} M{sub Sun }. The presence of this material so deep in the ejecta would imply substantial mixing, which may be related to asymmetries of the flame propagation. Another possible explanation for the carbon absorptions may be the existence of clumps of unburned material along the line of sight. However, the uniformity of the relation between C II and Si II velocities is not consistent with such small-scale asymmetries. The spectroscopic and photometric properties of SNe Ia with and without carbon signatures are compared. A trend toward bluer color and lower luminosity at maximum light is found for

  17. Effect of compositional heterogeneity on dissolution of non-ideal LNAPL mixtures

    Science.gov (United States)

    Vasudevan, M.; Johnston, C. D.; Bastow, T. P.; Lekmine, G.; Rayner, J. L.; Nambi, I. M.; Suresh Kumar, G.; Ravi Krishna, R.; Davis, G. B.

    2016-11-01

    The extent of dissolution of petroleum hydrocarbon fuels into groundwater depends greatly on fuel composition. Petroleum fuels can consist of thousands of compounds creating different interactions within the non-aqueous phase liquid (NAPL), thereby affecting the relative dissolution of the components and hence a groundwater plume's composition over long periods. Laboratory experiments were conducted to study the variability in the effective solubilities and activity coefficients for common constituents of gasoline fuels (benzene, toluene, p-xylene and 1,2,4-trimethylbenzene) (BTX) in matrices with an extreme range of molar volumes and chemical affinities. Four synthetic mixtures were investigated comprising BTX with the bulk of the NAPL mixtures made up of either, ethylbenzene (an aromatic like BTX with similar molar volume); 1,3,5-trimethylbenzene (an aromatic with a greater molar volume); n-hexane (an aliphatic with a low molar volume); and n-decane (an aliphatic with a high molar volume). Equilibrium solubility values for the constituents were under-predicted by Raoult's law by up to 30% (higher experimental concentrations) for the mixture with n-hexane as a filler and over-predicted by up to 12% (lower experimental concentrations) for the aromatic mixtures with ethylbenzene and 1,3,5-trimethylbenzene as fillers. Application of PP-LFER (poly-parameter linear free energy relationship) model for non-ideal mixtures also resulted in poor correlation between experimentally measured and predicted concentrations, indicating that differences in chemical affinities can be the major cause of deviation from ideal behavior. Synthetic mixtures were compared with the dissolution behavior of fresh and naturally weathered unleaded gasoline. The presence of lighter aliphatic components in the gasoline had a profound effect on estimating effective solubility due to chemical affinity differences (estimated at 0.0055 per percentage increase in the molar proportion of aliphatic) as

  18. Preliminary Investigation to Determine the Suitable Mixture Composition for Corn Starch Matrix

    Science.gov (United States)

    Huzaimi Zakaria, Nazri; Ngali, Zamani; Zulkefli Selamat, Mohd

    2017-01-01

    The use of natural fiber as reinforcement in polymeric composites has been seen a dramatically increase over the last decades. The surge in the interest of natural fiber composite or biodegradable composite is mainly due to the attractive cost of production, improved of hardness, better fatigue endurance and good thermal and mechanical resistivity. In this work, corn starch in the form of powder is utilized as the matrix of the composite. However, starch is brittle and has low strength make it inappropriate candidate for matrix binder. The main objective of this study is to modify the mechanical properties of pure corn starch by mixing it with water, glycerol and vinegar. The composition ratio of water is 60~80%, corn starch 10~35%, glycerol is 5~15% and vinegar is 0~5%, ten samples (A-J) have been manufactured and the best mixture composition is selected based on few selection criteria. The selection criteria are visual impaction, hardness and density. From the results, the samples without vinegar are not suitable to be used because of the fungus availability on the surface. Meanwhile the results from the samples with 5 ml vinegar have no fungus on their surface even has been exposed to the ambient air. While the sample C has shown the best sample based on the visual, hardness and density test.

  19. Theoretical Rocket Performance of Liquid Methane with Several Fluorine-Oxygen Mixtures Assuming Frozen Composition

    Science.gov (United States)

    Gordon, Sanford; Kastner, Michael E

    1958-01-01

    Theoretical rocket performance for frozen composition during expansion was calculated for liquid methane with several fluorine-oxygen mixtures for a range of pressure ratios and oxidant-fuel ratios. The parameters included are specific impulse, combustion-chamber temperature, nozzle-exit temperature molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, isentropic exponent, viscosity, and thermal conductivity. The maximum calculated value of specific impulse for a chamber pressure of 600 pounds per square inch absolute (40.827atm) and an exit pressure of 1 atmosphere is 315.3 for 79.67 percent fluorine in the oxidant.

  20. IDENTIFICATION OF PHASE COMPOSITION OF BINDERS FROM ALKALI-ACTIVATED MIXTURES OF GRANULATED BLAST FURNACE SLAG AND FLY ASH

    Directory of Open Access Journals (Sweden)

    JOZEF VLČEK

    2014-03-01

    Full Text Available The prepared alkali-activated binders (AAB and composites using suitable latent hydraulic raw materials represent an alternative to materials based on Portland cements. This paper deals with ways how to influence the functional parameters of AAB by setting up mixtures of granulated blast furnace slag (GBFS and fly ash with selected chemical compositions. In this way the course of hydration process is modified and the phase composition of products of alkali activation is changed as well as their final properties. The amorphous character of the hydration products makes evaluation of the phase composition of hardened AAB difficult and significantly limits the number of experimental techniques suitable to characterise their phase composition. It was observed that measuring the pH of water extracts obtained from the alkali-activated mixtures can give supplementary information about the process of hardening of alkali-activated mixtures of GBFS and fly ash.

  1. Identification of damage in composite structures using Gaussian mixture model-processed Lamb waves

    Science.gov (United States)

    Wang, Qiang; Ma, Shuxian; Yue, Dong

    2018-04-01

    Composite materials have comprehensively better properties than traditional materials, and therefore have been more and more widely used, especially because of its higher strength-weight ratio. However, the damage of composite structures is usually varied and complicated. In order to ensure the security of these structures, it is necessary to monitor and distinguish the structural damage in a timely manner. Lamb wave-based structural health monitoring (SHM) has been proved to be effective in online structural damage detection and evaluation; furthermore, the characteristic parameters of the multi-mode Lamb wave varies in response to different types of damage in the composite material. This paper studies the damage identification approach for composite structures using the Lamb wave and the Gaussian mixture model (GMM). The algorithm and principle of the GMM, and the parameter estimation, is introduced. Multi-statistical characteristic parameters of the excited Lamb waves are extracted, and the parameter space with reduced dimensions is adopted by principal component analysis (PCA). The damage identification system using the GMM is then established through training. Experiments on a glass fiber-reinforced epoxy composite laminate plate are conducted to verify the feasibility of the proposed approach in terms of damage classification. The experimental results show that different types of damage can be identified according to the value of the likelihood function of the GMM.

  2. Calcium phosphate composite cements based on simple mixture of brushite and apatite phases

    Science.gov (United States)

    Egorov, A. A.; Fedotov, A. Yu; Pereloma, I. S.; Teterina, A. Yu; Sergeeva, N. S.; Sviridova, I. K.; Kirsanova, V. A.; Akhmedova, S. A.; Nesterova, A. V.; Reshetov, I. V.; Barinov, S. M.; Komlev, V. S.

    2018-04-01

    The composite cements based on simple mixtures brishite and apatite with ratio 70/30, 50/50, 30/70 were developed. The processes of phase formation, microstructure and mechanical properties were studied. The kinetics of degradation in simulated body fluid depending on the microstructure and the materials phase composition was carried out. The biological test in vitro were performed using the MTT-test on the human fibroblast immortalized (hFB) cell line and the human osteosarcoma cell line MG-63. The materials didn’t have acute cytoxicity and possessed surface matrix properties. It was determined that the both line of cells actively proliferated, with viable cells values higher 20-60 % then control at all observation periods.

  3. Unburned Carbon from Samlaung Coal as Environmental Friendly Sorbent Material

    International Nuclear Information System (INIS)

    Zaw Naing; Tin Tin Aye; Nyunt Wynn; Kyaw Myo Naing

    2005-09-01

    The increasing role of coal as a source of energy in the 21st century will demand enviromental and cost-effective strategies for the use of carbonaceous waste products from coal combustion. The carbonaceous in fly ash, unburned carbon (UC), is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatization process while in the combustion, and therefore, only requires to be activated. This paper demonstrates the potential for converting UC from Samlaung coal to activated carbons. After heat activation at 970C, the UC sample was generated to activated carbons having microporous structure. This study concerns with adsorption behavior (decolourization and metal uptake) of UC from Samlaung coal. Batch tests and column tests were carried out. Adsorption isotherms has been obtained from these tests. Results show that the UC have equal or better adsorption capacity comparing with other activated carbons. It was found that heat treatment of Samlaung coal in the presence of air at 970C enhanced the adsorption capacity

  4. Mechanical Property Of Zeolite-PVA Composite Mixture Irradiated By Gamma Ray Of Co-60

    International Nuclear Information System (INIS)

    Darsono; Danu, Sugiarto; Las, Tamzil

    2000-01-01

    Experiment on preparation of zeolite-polyvinyl alcohol composite for absorbance materials have been done by curring using Gamma γ-ray of Co-60. Zeolite with the particles size of 60 mesh was mixed with polyvinyl alcohol (PVA) at the concentration of the mixture were 6,9, and 12% by weight, than they were poured into glass tube (length = 100 mm; diameter = 10 mm) and irradiated at the doses of 10, 20, 30 dan 40 kGy with the dose rate of 7,5 kGy/ hr. Parameters observed were density, compressive strength, and hardness. Experimental results showed that polyvinyl alcohol in the mixture was significant effect to density and compressive strength, where as the irradiation dose was highly significant effect to compressive strength. The effect interaction between dose and polyvinyl alcohol concentration factors had significant effect to density or compressive strength. Almost all samples have pencil hardness of 4 - 5 H, for composite containing 6 % PVA, has pencil hardness of 2 - 3 H

  5. Spontaneous Evolution of Nanostructure in Composite Films Consisting of Mixtures of Two Different Block Copolymer Micelles

    Science.gov (United States)

    Kim, Sehee; Char, Kookheon; Sohn, Byeong-Hyeok

    2010-03-01

    Diblock copolymers consisting of two immiscible polymer blocks covalently bonded together form various self-assembled nanostructures such as spheres, cylinders, and lamellae in bulk phase. In a selective solvent, however, they assemble into micelles with soluble corona brushes and immiscible cores. Both polystyrene-poly(4-vinylpyridine) (PS-b-P4VP) and polystyrene-poly(2-vinylpyridine) (PS-b-P2VP) diblock copolymers form micelles with PS coronas and P4VP or P2VP cores in a PS selective solvent (toluene). By varying the mixture ratio between PS-b-P4VP and PS-b-P2VP, composite films based on the micellar mixtures of PS-b-P4VP and PS-b-P2VP were obtained by spin-coating, followed by the solvent annealing with tetrahydrofuran (THF) vapor. Since THF is a solvent for both PS and P2VP blocks and, at the same time, a non-solvent for the P4VP block, PS-P2VP micelles transformed to lamellar multilayers while PS-P4VP micelles remained intact during the THF annealing. The spontaneous evolution of nanostructure in composite films consisting of lamellae layers with BCP micelles were investigated in detail by cross-sectional TEM and AFM.

  6. Thermo-Chemical Conversion of Microwave Activated Biomass Mixtures

    Science.gov (United States)

    Barmina, I.; Kolmickovs, A.; Valdmanis, R.; Vostrikovs, S.; Zake, M.

    2018-05-01

    Thermo-chemical conversion of microwave activated wheat straw mixtures with wood or peat pellets is studied experimentally with the aim to provide more effective application of wheat straw for heat energy production. Microwave pre-processing of straw pellets is used to provide a partial decomposition of the main constituents of straw and to activate the thermo-chemical conversion of wheat straw mixtures with wood or peat pellets. The experimental study includes complex measurements of the elemental composition of biomass pellets (wheat straw, wood, peat), DTG analysis of their thermal degradation, FTIR analysis of the composition of combustible volatiles entering the combustor, the flame temperature, the heat output of the device and composition of the products by comparing these characteristics for mixtures with unprocessed and mw pre-treated straw pellets. The results of experimental study confirm that mw pre-processing of straw activates the thermal decomposition of mixtures providing enhanced formation of combustible volatiles. This leads to improvement of the combustion conditions in the flame reaction zone, completing thus the combustion of volatiles, increasing the flame temperature, the heat output from the device, the produced heat energy per mass of burned mixture and decreasing at the same time the mass fraction of unburned volatiles in the products.

  7. Chemical mixtures in untreated water from public-supply wells in the U.S.--occurrence, composition, and potential toxicity.

    Science.gov (United States)

    Toccalino, Patricia L; Norman, Julia E; Scott, Jonathon C

    2012-08-01

    Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. Published by Elsevier B.V.

  8. Laser induced breakdown in gas mixtures. Experimental and statistical investigation on n-decane ignition: Pressure, mixture composition and equivalence ratio effects.

    Science.gov (United States)

    Mokrani, Nabil; Gillard, Philippe

    2018-03-26

    This paper presents a physical and statistical approach to laser-induced breakdown in n-decane/N 2  + O 2 mixtures as a function of incident or absorbed energy. A parametric study, with pressure, fuel purity and equivalence ratio, was conducted to determine the incident and absorbed energies involved in producing breakdown, followed or not by ignition. The experiments were performed using a Q-switched Nd-YAG laser (1064 nm) inside a cylindrical 1-l combustion chamber in the range of 1-100 mJ of incident energy. A stochastic study of breakdown and ignition probabilities showed that the mixture composition had a significant effect on ignition with large variation of incident or absorbed energy required to obtain 50% of breakdown. It was observed that the combustion products absorb more energy coming from the laser. The effect of pressure on the ignition probabilities of lean and near stoichiometric mixtures was also investigated. It was found that a high ignition energy E50% is required for lean mixtures at high pressures (3 bar). The present study provides new data obtained on an original experimental setup and the results, close to laboratory-produced laser ignition phenomena, will enhance the understanding of initial conditions on the breakdown or ignition probabilities for different mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Soot, unburned carbon and ultrafine particle emissions from air- and oxy-coal flames

    International Nuclear Information System (INIS)

    Morris, W.J.; Yu, Dunxi; Wendt, J.O.L.

    2010-01-01

    Oxy-coal combustion is one possible solution for the mitigation of greenhouse gases. In this process coal is burned in oxygen, rather than air, and the temperatures in the boiler are mitigated by recycling flue gases, so that the inlet mixture may contain either 27 % O 2 to match adiabatic flame temperatures, or 32 % O 2 to match gaseous radiation heat fluxes in the combustion chamber. However, a major issue for heat transfer from coal combustion is the radiative heat transmission from soot. For this research, air and oxy coal firing were compared regarding the emission of soot. A 100 kW down-fired laboratory combustor was used to determine effects of switching from air to oxy-firing on soot, unburned carbon and ultrafine particle emissions from practical pulverized coal flames. Of interest here were potential chemical effects of substitution of the N 2 in air by CO 2 in practical pulverized coal flames. The oxy-coal configuration investigated used once-through CO 2 , simulating cleaned flue gas recycle with all contaminants and water removed. Three coals were each burned in: a) air, b) 27 % O 2 / 73 % CO 2 , c) 32 % O 2 / 68 % CO 2 . Tests were conducted at (nominally) 3 %, 2 %, 1 % and 0 % O 2 in the exhaust (dry basis). For each condition, particulate samples were iso kinetically withdrawn far from the radiant zone, and analyzed using a photoacoustic analyzer (PA) for black carbon, a scanning mobility particle sizer (SMPS) for ultrafine particles, and a total sample loss on ignition (LOI) method for unburned carbon in ash. Data suggest that at low stoichiometric ratios, ultrafine particles consist primarily of black carbon, which, for the bituminous coal, is produced in lesser amounts under oxy-fired conditions than under the air-fired condition, even when adiabatic flame temperatures are matched. However, significant changes in mineral matter vaporization were not observed unless the flames were hotter. These and other results are interpreted in the light of

  10. Chemical mixtures in untreated water from public-supply wells in the U.S. - Occurrence, composition, and potential toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Toccalino, Patricia L., E-mail: ptocca@usgs.gov [U.S. Geological Survey (USGS), 6000 J Street, Placer Hall, Sacramento, California 95819 (United States); Norman, Julia E., E-mail: jnorman@usgs.gov [USGS, 2130 SW 5th Avenue, Portland, Oregon 97201 (United States); Scott, Jonathon C., E-mail: jon@usgs.gov [USGS, 202 NW 66th Street, Oklahoma City, Oklahoma 73116 (United States)

    2012-08-01

    Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. - Highlights: Black-Right-Pointing-Pointer We assessed mixtures in untreated groundwater samples from public

  11. Complex-shaped ceramic composites obtained by machining compact polymer-filler mixtures

    Directory of Open Access Journals (Sweden)

    Rosa Maria da Rocha

    2005-06-01

    Full Text Available Research in the preparation of ceramics from polymeric precursors is giving rise to increased interest in ceramic technology because it allows the use of several promising polymer forming techniques. In this work ceramic composite pieces were obtained by pyrolysis of a compacted mixture of a polysiloxane resin and alumina/silicon powder. The mixture consists of 60 vol% of the polymer phase and 40 vol% of the filler in a 1:1 ratio for alumina/silicon, which was hot pressed to crosslink the polymer, thus forming a compact body. This green body was trimmed into different geometries and pyrolised in nitrogen atmosphere at temperatures up to 1600 °C. X-ray diffraction analysis indicated the formation of phases such as mullite and Si2ON2 during pyrolysis, that result from reactions between fillers, polymer decomposition products and nitrogen atmosphere. The porosity was found to be less than 20% and the mass loss around 10%. The complex geometry was maintained after pyrolysis and shrinkage was approximately 8%, proving pyrolisis to be a suitable process to form near-net-shaped bulk ceramic components.

  12. Structural comparison of sintering products made of "TiC + Ti" composite powders and "Ti + C" powder mixtures

    Science.gov (United States)

    Krinitcyn, Maksim G.; Pribytkov, Gennadii A.; Korosteleva, Elena N.; Firsina, Irina A.; Baranovskii, Anton V.

    2017-12-01

    In this study, powder composite materials comprised of TiC and Ti with different ratios are processed by sintering of Ti and C powder mixtures and self-propagating high-temperature synthesis (SHS) in "Ti+C" system followed by sintering. The microstructure and porosity of obtained composites are investigated and discussed. The dependence of porosity on sintering time is explained theoretically. Optimal regimes that enable to obtain the most homogeneous structure with the least porosity are described.

  13. The Determination of the Optimal Material Proportion in Natural Fiber-Cement Composites Using Design of Mixture Experiments

    OpenAIRE

    Aramphongphun Chuckaphun; Ungtawondee Kampanart; Chaysuwan Duangrudee

    2016-01-01

    This research aims to determine the optimal material proportion in a natural fiber-cement composite as an alternative to an asbestos fibercement composite while the materials cost is minimized and the properties still comply with Thai Industrial Standard (TIS) for applications of profile sheet roof tiles. Two experimental sets were studied in this research. First, a three-component mixture of (i) virgin natural fiber, (ii) synthetic fiber and (iii) cement was studied while the proportion of c...

  14. Crystal nucleation in binary hard-sphere mixtures: the effect of order parameter on the cluster composition

    NARCIS (Netherlands)

    Ni, R.; Smallenburg, F.; Filion, L.C.; Dijkstra, M.

    2011-01-01

    We study crystal nucleation in a binary mixture of hard spheres and investigate the composition and size of the (non)critical clusters using Monte Carlo simulations. In order to study nucleation of a crystal phase in computer simulations, a one-dimensional order parameter is usually defined to

  15. Radiation Shielding of Lunar Regolith/Polyethylene Composites and Lunar Regolith/Water Mixtures

    Science.gov (United States)

    Johnson, Quincy F.; Gersey, Brad; Wilkins, Richard; Zhou, Jianren

    2011-01-01

    Space radiation is a complex mixed field of ionizing radiation that can pose hazardous risks to sophisticated electronics and humans. Mission planning for lunar exploration and long duration habitat construction will face tremendous challenges of shielding against various types of space radiation in an attempt to minimize the detrimental effects it may have on materials, electronics, and humans. In late 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) discovered that water content in lunar regolith found in certain areas on the moon can be up to 5.6 +/-2.8 weight percent (wt%) [A. Colaprete, et. al., Science, Vol. 330, 463 (2010). ]. In this work, shielding studies were performed utilizing ultra high molecular weight polyethylene (UHMWPE) and aluminum, both being standard space shielding materials, simulated lunar regolith/ polyethylene composites, and simulated lunar regolith mixed with UHMWPE particles and water. Based on the LCROSS findings, radiation shielding experiments were conducted to test for shielding efficiency of regolith/UHMWPE/water mixtures with various percentages of water to compare relative shielding characteristics of these materials. One set of radiation studies were performed using the proton synchrotron at the Loma Linda Medical University where high energy protons similar to those found on the surface of the moon can be generated. A similar experimental protocol was also used at a high energy spalation neutron source at Los Alamos Neutron Science Center (LANSCE). These experiments studied the shielding efficiency against secondary neutrons, another major component of space radiation field. In both the proton and neutron studies, shielding efficiency was determined by utilizing a tissue equivalent proportional counter (TEPC) behind various thicknesses of shielding composite panels or mixture materials. Preliminary results from these studies indicated that adding 2 wt% water to regolith particles could increase shielding of

  16. Determination of Specific Heat Capacity on Composite Shape-Stabilized Phase Change Materials and Asphalt Mixtures by Heat Exchange System.

    Science.gov (United States)

    Ma, Biao; Zhou, Xue-Yan; Liu, Jiang; You, Zhanping; Wei, Kun; Huang, Xiao-Feng

    2016-05-19

    Previous research has shown that composite shape-stabilized phase change material (CPCM) has a remarkable capacity for thermal storage and stabilization, and it can be directly applied to highway construction without leakage. However, recent studies on temperature changing behaviors of CPCM and asphalt mixture cannot intuitively reflect the thermoregulation mechanism and efficiency of CPCM on asphalt mixture. The objective of this paper is to determine the specific heat capacity of CPCM and asphalt mixtures mixed with CPCM using the heat exchange system and the data acquisition system. Studies have shown that the temperature-rise curve of 5 °C CPCM has an obvious temperature plateau, while an asphalt mixture mixed with 5 °C CPCM does not; with increasing temperature, the specific heat capacities of both 5 °C CPCM and asphalt mixture first increase and then decrease, while the variation rate of 5 °C CPCM is larger than that of the asphalt mixture, and the maximum specific heat capacity of 5 °C CPCM appears around the initial phase change temperature. It is concluded that the temperature intervals of 5 °C CPCM are -18 °C-7 °C, 7 °C-25 °C and 25 °C-44 °C, respectively, and that of the asphalt mixture are -18 °C~10 °C, -10 °C~5 °C and 5 °C~28 °C. A low dosage of 5 °C CPCM has little influence on the specific heat capacity of asphalt mixture. Finally, the functions of specific heat capacities and temperature for CPCM and asphalt mixture mixed with CPCM were recommended by the sectional regression method.

  17. Inclusion of caraway in the ryegrass-red clover mixture modifies soil microbial community composition

    DEFF Research Database (Denmark)

    Cong, Wenfeng; Jing, Jingying; Søegaard, Karen

    -containing grass-clover mixtures may potentially affect soil microbial community structure, biomass and associated ecosystem functions, but it is yet to be elucidated. We hypothesized that inclusion of plantain in the grass-clover mixture would enhance soil microbial biomas and functions through its high biomass...

  18. Interlaminar improvement of carbon fiber/epoxy composites via depositing mixture of carbon nanotubes and sizing agent

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Cuiqin [Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing 100029 (China); Wang, Julin, E-mail: julinwang@126.com [Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang, Tao [Beijing Institute of Ancient Architecture, Beijing 100050 (China)

    2014-12-01

    Graphical abstract: - Highlights: • COOH-CNTs can react with sizing agent, and the optimum reaction ratio was 1:20. • Carbon fibers were dipped into the mixture bath of CNTs and sizing agent. • SEM results indicate that fibers surfaces were coated with CNTs and sizing agent. • ILSS was increased by 67.01% for the composites after the mixture coating process. • Single fibers tensile strength was maintained after the deposited process. - Abstract: The effects of deposition to carbon fibers surfaces with mixture of functionalized multi-walled carbon fibers (MWCNTs) and sizing agent were investigated. Relationships between CNTs and sizing agent were studied with Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectroscopy (XPS) and Ubbelohde viscometer. The results revealed that CNTs could react with sizing agent at 120 °C, and optimal reaction occurs when mass ratio was about 1:20. Then, carbon fibers were immersed in mixed aqueous suspension of CNTs and sizing agent with the above ratio dispersed by ultrasonication. According to scanning electron microscope (SEM) observations, fibers surfaces were coated with CNTs and sizing agent. The static contact angle tests indicated wetting performance between fibers and epoxy resin were improved after deposited procedures. Interlaminar shear strength was increased by 67.01% for fibers/epoxy resin composites after mixture deposited process. Moreover, the tensile strength of single fibers after depositing showed a slightly increase compared with that of fibers without depositing layer.

  19. Data on coffee composition and mass spectrometry analysis of mixtures of coffee related carbohydrates, phenolic compounds and peptides

    Directory of Open Access Journals (Sweden)

    Ana S.P. Moreira

    2017-08-01

    Full Text Available The data presented here are related to the research paper entitled “Transglycosylation reactions, a main mechanism of phenolics incorporation in coffee melanoidins: inhibition by Maillard reaction” (Moreira et al., 2017 [1]. Methanolysis was applied in coffee fractions to quantify glycosidically-linked phenolics in melanoidins. Moreover, model mixtures mimicking coffee beans composition were roasted and analyzed using mass spectrometry-based approaches to disclose the regulatory role of proteins in transglycosylation reactions extension. This article reports the detailed chemical composition of coffee beans and derived fractions. In addition, it provides gas chromatography–mass spectrometry (GC–MS chromatograms and respective GC–MS spectra of silylated methanolysis products obtained from phenolic compounds standards, as well as the detailed identification of all compounds observed by electrospray mass spectrometry (ESI-MS analysis of roasted model mixtures, paving the way for the identification of the same type of compounds in other samples.

  20. Spatial and Temporal Patterns of Unburned Areas within Fire Perimeters in the Northwestern United States from 1984 to 2014

    Science.gov (United States)

    Meddens, A. J.; Kolden, C.; Lutz, J. A.; Abatzoglou, J. T.; Hudak, A. T.

    2016-12-01

    Recently, there has been concern about increasing extent and severity of wildfires across the globe given rapid climate change. Areas that do not burn within fire perimeters can act as fire refugia, providing (1) protection from the detrimental effects of the fire, (2) seed sources, and (3) post-fire habitat on the landscape. However, recent studies have mainly focused on the higher end of the burn severity spectrum whereas the lower end of the burn severity spectrum has been largely ignored. We developed a spatially explicit database for 2,200 fires across the inland northwestern USA, delineating unburned areas within fire perimeters from 1984 to 2014. We used 1,600 Landsat scenes with one or two scenes before and one or two scenes after the fires to capture the unburned proportion of the fire. Subsequently, we characterized the spatial and temporal patterns of unburned areas and related the unburned proportion to interannual climate variability. The overall classification accuracy detecting unburned locations was 89.2% using a 10-fold cross-validation classification tree approach in combination with 719 randomly located field plots. The unburned proportion ranged from 2% to 58% with an average of 19% for a select number of fires. We find that using both an immediate post-fire image and a one-year post fire image improves classification accuracy of unburned islands over using just a single post-fire image. The spatial characteristics of the unburned islands differ between forested and non-forested regions with a larger amount of unburned area within non-forest. In addition, we show trends of unburned proportion related primarily to concurrent climatic drought conditions across the entire region. This database is important for subsequent analyses of fire refugia prioritization, vegetation recovery studies, ecosystem resilience, and forest management to facilitate unburned islands through fuels breaks, prescribed burning, and fire suppression strategies.

  1. Study on mechanical properties of fly ash impregnated glass fiber reinforced polymer composites using mixture design analysis

    International Nuclear Information System (INIS)

    Satheesh Raja, R.; Manisekar, K.; Manikandan, V.

    2014-01-01

    Highlights: • FRP with and without fly ash filler were prepared. • Mechanical properties of composites were analyzed. • Mixture Design Method was used to model the system. • Experimental and mathematical model results were compared. - Abstract: This paper describes the mechanical behavior of fly ash impregnated E-glass fiber reinforced polymer composite (GFRP). Initially the proportion of fiber and resin were optimized from the analysis of the mechanical properties of the GFRP. It is observed that the 30 wt% of E-glass in the GFRP without filler material yields better results. Then, based on the optimized value of resin content, the varying percentage of E-glass and fly ash was added to fabricate the hybrid composites. Results obtained in this study were mathematically evaluated using Mixture Design Method. Predictions show that 10 wt% addition of fly ash with fiber improves the mechanical properties of the composites. The fly ash impregnated GFRP yields significant improvement in mechanical strength compared to the GFRP without filler material. The surface morphologies of the fractured specimens were characterized using Scanning Electron Microscope (SEM). The chemical composition and surface morphology of the fly ash is analyzed by using Energy Dispersive Spectroscopy (EDS) and Scanning Electron Microscope

  2. Experimental and theoretical investigation on unburned coal char burnout in a pilot-scale rotary kiln

    Energy Technology Data Exchange (ETDEWEB)

    Federico Cangialosi; Francesco Di Canio; Gianluca Intini; Michele Notarnicola; Lorenzo Liberti; Giulio Belz; Pompilio Caramuscio [Technical University of Bari, Taranto (Italy). Department of Environmental Engineering and Sustainable Development

    2006-11-15

    Oxidation reactivity studies are imperative for improving carbon re-burn technologies and valuing the heat content of unburned carbon within coal combustion ashes. Non-isothermal, thermal gravimetric analysis (TGA) was used to examine the oxidation kinetics of unburned carbon in coal combustion fly ashes having different particle size distributions; TGA results were related to combustion efficiencies as measured in a bench-scale rotary kiln. The activation energy and pre-exponential factor were determined for the chemically-controlled reaction regime; the transition temperatures between chemically-controlled and partially diffusion-controlled combustion regimes were obtained for unburned carbon particles of different sizes. After the oxidation reaction rates were evaluated, the residence time distribution (RTD) of fly ashes in the rotary kiln were experimentally measured and the mean residence times related to process parameters, including the rotating velocity and kiln inclination. By comparing these results with an advective-dispersive model, the axial dispersion coefficient of fly ashes was determined. The reaction rates obtained by thermal analyses and the RTDs were used to predict combustion efficiencies within the kiln and oxidation conditions of unburned carbon using various processing options. 21 refs., 6 figs., 4 tabs.

  3. Analysis of unburned carbon in industrial ashes from biomass combustion by thermogravimetric method using Boudouard reaction

    Czech Academy of Sciences Publication Activity Database

    Straka, Pavel; Náhunková, Jana; Žaloudková, Margit

    2014-01-01

    Roč. 575, JAN (2014), s. 188-194 ISSN 0040-6031 R&D Projects: GA MZe QI102A207 Institutional support: RVO:67985891 Keywords : unburned carbon * biomass * ash * thermogravimetry Subject RIV: GD - Fertilization, Irrigation, Soil Processing Impact factor: 2.184, year: 2014 http://www.sciencedirect.com/science/article/pii/S0040603113005455

  4. Composition of some botanical mixtures as potential feed additives for laying hens

    Directory of Open Access Journals (Sweden)

    Varzaru Iulia

    2015-01-01

    Full Text Available The aim of this study was to assess the nutritional quality of four botanical mixtures (AFC: AFC 1 (containing red corn, pumpkin pulp and marigold, AFC 2 (containing alfalfa meal, pumpkin pulp and marigold, AFC 3 (containing kale, alfalfa meal, marigold and spinach leaves, AFC 4 (containing buckthorn, red corn, pumpkin pulp and marigold, in terms of proximate analysis (crude protein, crude fat, crude fiber, ash, amino acid (AA profile, vitamin E concentration and lutein and zeaxanthin content, in order to determine the potential of AFCs as feed additives in laying hens nutrition. The crude protein content for the analysed botanical mixtures ranged between 9.07-18.18% DM, and crude fiber between 10.41-30.83% DM. The amino acid profile of the mixture AFC 4 revealed a content of limiting essential amino acids required for laying hens: lysine 5.719% CP, methionine 1.058% CP and threonine 4.415% CP. The highest content of lutein and zeaxanthin was found in the mixture AFC 4 (66.659 mg/100 g, which also had the highest amount of vitamin E (640.93 mg/kg. With regard to safety of the botanical mixtures, lead and cadmium concentrations were determined. Concentration of lead ranged from 0.28-0.75 µg/g DM and 0.06-0.09 µg/g DM for concentration of cadmium, which was within the legislation of maximal limits of EU regulations. It can be concluded that the botanical mixture AFC 4 had the highest concentration of lutein, zeaxanthin and vitamin E, with an adequate content of essential amino acids. Furthermore, all four botanical mixtures had high amounts of xantophylls and should be tested in laying hens trials in order to establish their effects on lutein and zeaxanthin concentration in egg yolk.

  5. Effect of composition of chlorophyll and ruthenium dyes mixture (hybrid) on the dye-sensitized solar cell performance

    Science.gov (United States)

    Pratiwi, D. D.; Nurosyid, F.; Kusumandari; Supriyanto, A.; Suryana, R.

    2018-03-01

    The fabrication of dye-sensitized solar cell (DSSC) has been conducted by varying the composition of natural dye from moss chlorophyll (Bryophyte) and synthesis dye from ruthenium complex N719. The sandwich structure of DSSC consists of the working electrode using TiO2, dye, electrolyte, and counter electrode using carbon. The composition of chlorophyll and synthesis dyes mixture were 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80%. The UV-Vis absorption spectra of moss chlorophyll showed the first peak in the wavelength range of 450-500 nm and the second peak at wavelength of 650-700 nm. The peak value of absorbance at wavelengths of 450-500 nm was 6.1004 and at wavelengths of 650-700 nm was 3.5835. The IPCE characteristic curves showed the absorption peak of photon for DSSCs occurred at wavelength of 550-650 nm. It considered that photon in this wavelength can contribute dominantly to produce the optimum electrons. The I-V characteristics of DSSCs with composition of chlorophyll and synthesis dyes mixture of 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80% resulted the efficiency of 0.0022; 0.0194; 0.0239; 0.0342; and 0.0414, respectively. It suggested that the addition of a little composition of the ruthenium complex dye into moss chlorophyll dye can increase the efficiency significantly.

  6. Composition dependence of the synergistic effect of nucleating agent and plasticizer in poly(lactic acid: A Mixture Design study

    Directory of Open Access Journals (Sweden)

    M. K. Fehri

    2016-04-01

    Full Text Available Blends consisting of commercial poly(lactic acid (PLA, poly(lactic acid oligomer (OLA8 as plasticizer and a sulfonic salt of a phthalic ester and poly(D-lactic acid as nucleating agents were prepared by melt extrusion, following a Mixture Design approach, in order to systematically study mechanical and thermal properties as a function of composition. The full investigation was carried out by differential scanning calorimetry (DSC, dynamic mechanical thermal analysis (DMTA and tensile tests. The crystallization half-time was also studied at 105 °C as a function of the blends composition. A range of compositions in which the plasticizer and the nucleation agent minimized the crystallization half-time in a synergistic way was clearly identified thanks to the application of the Mixture Design approach. The results allowed also the identification of a composition range to maximize the crystallinity developed during the rapid cooling below glass transition temperature in injection moulding, thus allowing an easier processing of PLA based materials. Moreover the mechanical properties were discussed by correlating them to the chemical structural features and thermal behaviour of blends.

  7. Direct numerical simulations of ignition of a lean n-heptane/air mixture with temperature and composition inhomogeneities relevant to HCCI and SCCI combustion

    KAUST Repository

    Luong, Minh Bau; Yu, Gwang Hyeon; Lu, Tianfeng; Chung, Suk-Ho; Yoo, Chun Sang

    2015-01-01

    The effects of temperature and composition stratifications on the ignition of a lean n-heptane/air mixture at three initial mean temperatures under elevated pressure are investigated using direct numerical simulations (DNSs) with a 58-species

  8. Effect of seed mixture composition and management on competitiveness of herbs in temporary grasslands

    DEFF Research Database (Denmark)

    Mortensen, Tine Bloch; Søegaard, Karen; Eriksen, Jørgen

    2012-01-01

    of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens), 2) cutting frequency, and 3) slurry application. The experiment was carried out over three years. The herb mixture contained salad burnet (Sanguisorba minor), fenugreek (Trigonella foenum-graecum), chicory (Cichcorium intybus), caraway...

  9. Plant composition, pharmacological properties and mutagenic evaluation of a commercial Zulu herbal mixture: Imbiza ephuzwato.

    Science.gov (United States)

    Ndhlala, A R; Finnie, J F; Van Staden, J

    2011-01-27

    Imbiza ephuzwato is a traditional herbal tonic made from a mixture of extracts of roots, bulbs, rhizomes and leaves of 21 medicinal plants and is used in traditional medicine as a multipurpose remedy. To compile and investigate the bioactivity and mutagenic effects of extracts of the 21 plant species used in the preparation of Imbiza ephuzwato herbal tonic. The 21 plant species used to make Imbiza ephuzwato herbal mixture were each investigated for their pharmacological properties. Petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water extracts of the 21 plants were evaluated against two gram-positive, two gram-negative bacteria and a fungus Candida albicans. The extracts were also evaluated for their inhibitory effects against cyclooxygenase (COX-1 and -2) and acetylcholinesterase AChE enzymes. Mutagenic effects of the water extracts were evaluated using the Ames test. Gunnera perpensa and Rubia cordifolia were the only plant species used to manufacture Imbiza ephuzwato that had water extracts which showed good antibacterial activity. The extracts of G. perpensa (EtOH), Hypericum aethiopicum (DCM) and Urginea physodes (EtOH) showed the best antifungal activity. The water extracts of H. aethiopicum, G. perpensa, Drimia robusta, Vitellariopsis marginata, Scadoxus puniceus and Momordica balsamina showed percentage inhibition of COX-1 that was over 70%. For COX-2 enzyme, the water extracts of G. perpensa, Cyrtanthus obliquus, M. balsamina and Tetradenia riparia exhibited inhibitory activity above 70%. Water extracts of G. perpensa, C. obliquus, V. marginata, Asclepias fruticosa and Watsonia densiflora showed good AChE inhibitory activity (>80%). The Ames test results revealed that all the water extracts of the 21 plant species used to make Imbiza ephuzwato were non-mutagenic towards the Salmonella typhimurium TA98 strain for the assay with and without S9 metabolic activation. In contrast, Imbiza ephuzwato showed mutagenic effects after exposure to S

  10. Radiative surface temperatures of the burned and unburned areas in a tallgrass prairie

    International Nuclear Information System (INIS)

    Asrar, G.; Harris, T.R.; Lapitan, R.L.; Cooper, D.I.

    1988-01-01

    This study was conducted in a natural tallgrass prairie area in the Flint Hills of Kansas. Our objective was to evaluate the surface radiative temperatures of burned and unburned treatments of the grassland as a means of delineating the areas covered by each treatment. Burning is used to remove the senescent vegetation resulting from the previous year's growth. Surface temperatures were obtained in situ and by an airborne scanner. Burned and unburned grass canopies had distinctly different diurnal surface radiative temperatures. Measurements of surface energy balance components revealed a difference in partitioning of the available energy between the two canopies, which resulted in the difference in their measured surface temperatures. The magnitude of this difference is dependent on the time of measurements and topographic conditions. (author)

  11. Precise Composition Tailoring of Mixed-Cation Hybrid Perovskites for Efficient Solar Cells by Mixture Design Methods.

    Science.gov (United States)

    Li, Liang; Liu, Na; Xu, Ziqi; Chen, Qi; Wang, Xindong; Zhou, Huanping

    2017-09-26

    Mixed anion/cation perovskites absorber has been recently implemented to construct highly efficient single junction solar cells and tandem devices. However, considerable efforts are still required to map the composition-property relationship of the mixed perovskites absorber, which is essential to facilitate device design. Here we report the intensive exploration of mixed-cation perovskites in their compositional space with the assistance of a rational mixture design (MD) methods. Different from the previous linear search of the cation ratios, it is found that by employing the MD methods, the ternary composition can be tuned simultaneously following simplex lattice designs or simplex-centroid designs, which enable significantly reduced experiment/sampling size to unveil the composition-property relationship for mixed perovskite materials and to boost the resultant device efficiency. We illustrated the composition-property relationship of the mixed perovskites in multidimension and achieved an optimized power conversion efficiency of 20.99% in the corresponding device. Moreover, the method is demonstrated to be feasible to help adjust the bandgap through rational materials design, which can be further extended to other materials systems, not limited in polycrystalline perovskites films for photovoltaic applications only.

  12. Peculiarities of spectroscopic determination of the isotopic hydrogen composition in a mixture with neon and argon

    International Nuclear Information System (INIS)

    Nemets, V.M.; Petrov, A.A.; Solov'ev, A.A.

    1987-01-01

    The dependence of the relative intensity of atomic lines of hydrogen isotopes in the mixture with neon and argon during excitation in a high-frequency discharge under medium and high pressures is investigated. A physical model is suggested for processes determining the isotopic effects in the atomic hydrogen spectrum due to isotopic differences in velocity constants of dissociation-association, transfer and ionic-molecular reactions in a gas discharge plasma

  13. Study of influence of gas mixture composition on the multistep avalanche chambers characteristics

    International Nuclear Information System (INIS)

    Abdushukurov, D.A.; Zanevskij, Yu.V.; Peshekhonov, V.D.

    1987-01-01

    The influence of the concentration of organic quenchers on the operation of multistep avalanche chambers /MSAC/ has been studied. An empirical dependence of the gas amplification factor of MSAC on the quencher concentration has been derived. Measures are considered to increase the stability of the MSAC operation. To improve the MSAC operation argon + n-heptane, neon + methane and neon + argon + methane mixtures are suggested

  14. Partial least squares analysis and mixture design for the study of the influence of composition variables on lipidic nanoparticle characteristics.

    Science.gov (United States)

    Malzert-Fréon, A; Hennequin, D; Rault, S

    2010-11-01

    Lipidic nanoparticles (NP), formulated from a phase inversion temperature process, have been studied with chemometric techniques to emphasize the influence of the four major components (Solutol®, Labrasol®, Labrafac®, water) on their average diameter and their distribution in size. Typically, these NP present a monodisperse size lower than 200 nm, as determined by dynamic light scattering measurements. From the application of the partial least squares (PLS) regression technique to the experimental data collected during definition of the feasibility zone, it was established that NP present a core-shell structure where Labrasol® is well encapsulated and contributes to the structuring of the NP. Even if this solubility enhancer is regarded as a pure surfactant in the literature, it appears that the oil moieties of this macrogolglyceride mixture significantly influence its properties. Furthermore, results have shown that PLS technique can be also used for predictions of sizes for given relative proportions of components and it was established that from a mixture design, the quantitative mixture composition to use in order to reach a targeted size and a targeted polydispersity index (PDI) can be easily predicted. Hence, statistical models can be a useful tool to control and optimize the characteristics in size of NP. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association

  15. Influence of parameters of mixing of the mortar mixtures on the performance of ornamental composites for facade coating

    Directory of Open Access Journals (Sweden)

    Tkach Evgeniay

    2017-01-01

    Full Text Available Studies have shown that the main physical-mechanical properties of decorative coatings based on colloidal cement systems greatly depend on the homogeneity of the structure of hardened stone, therefore, in the preparation of mortar mixtures were set the task of achieving this target. It is shown that vibrational mix of materials helps to ensure the preparation of mortar mixes with cement-based colloidal systems with a more homogeneous distribution of the components. The efficiency of vibrational mixing was determined by comparing the strength of the mortar mixes based on colloidal cement glue, cooked in vibromaster when the vibration acceleration with the strength of samples prepared in a standard mortar mixer of forced action without vibration. The results of the research confirmed some influence of the mineralogical composition of clinker the cement component of the colloidal material on the effect of vibration treatment solutions. Parameters preparation of the mortar mixtures based on cement colloidal material in a vibratory mixer. Optimum resonant operating frequency of the vibrations, at which is achieved the positive effect of mixing of the mixture is ensured with amplitude 5mm while accelerating 214,8 m/S2 and duration of mixing 60-90s. It is established that vibropressure contributes to the intensification hydration processes to temperature is minus 5 0С

  16. Removal of unburned carbon in fly ash produced in coal combustion process

    International Nuclear Information System (INIS)

    Velasquez V, Leonardo F; De La Cruz M, Javier F; Sanchez M, Jhon F

    2007-01-01

    The coal unburned in flying ashes obtained in the processes of coal combustion is the main disadvantage for its use in the industry of the construction. This material normally has a size of particle greater than the mineral material, therefore it is possible to be separated in a considerable percentage, obtaining double benefit: the reusability of unburned like fuel or precursor for the activated charcoal production and the use of the mineral material in the industry of the construction since the organic matter has retired him that disables its use. In this work it is experienced with a sifted technique of separation by for three obtained flying ash samples with different technology (travelling Grill, pneumatic injection and overturning grill), were made grain sized analyses with meshes of a diameter of particle greater to 0,589 mm, the short analyses were made to them next to the retained material in each mesh and the unburned percentage of removal was determined of. The technique was compared with other developing.

  17. Experimental research on the influence of system parameters on the composition shift for zeotropic mixture (isobutane/pentane) in a system occurring phase change

    International Nuclear Information System (INIS)

    Bao, Junjiang; Zhao, Li

    2016-01-01

    Highlights: • The influence of system parameters on the composition shift for zeotropic mixture is studied. • Zeotropic mixture isobutane/pentane is selected as the working fluids. • Circulating composition and charge have the inverse proportion relationship. • The relationship between circulating composition and charge composition is linear. - Abstract: Zeotropic mixture can improve the performance of the thermodynamic cycle ascribed to the better temperature match during the heat transfer process with the characteristics of temperature glide during evaporation and condensing processes. Another characteristic of zeotropic mixture is composition shift. Composition shift means that the circulating composition and charge composition is different and is mainly caused by the two-phase hold-up and different solubility in lubricating oil. The existence of composition shift will affect the design and operation of thermodynamic system. The previous study gave little information about the influence of system parameters on the composition shift in a system occurring phase change. This paper mainly discuss the influence of system parameters on the composition shift for zeotropic mixture in a system occurring phase change as well as the validation of the linear relationship between the circulating composition and the charge composition and the inverse proportion relationship between the circulating composition and the charge mass found based on our previous theory study (Zhao and Bao, 2014). With isobutane and pentane as the research object, the impact of the key system parameters (hot water temperature, mass flow rate of hot water, feed pump frequency, cold water temperature and evaporator length) on composition shift are experimentally carried out. The results show that when the hot water temperature, mass flow rate of hot water and evaporator length increase and cold water temperature decreases, circulating composition will increase. For feed pump frequency, when

  18. Fatty acid composition of ruminal digesta and longissimus muscle from lambs fed silage mixtures including red clover, sainfoin, and timothy.

    Science.gov (United States)

    Campidonico, L; Toral, P G; Priolo, A; Luciano, G; Valenti, B; Hervás, G; Frutos, P; Copani, G; Ginane, C; Niderkorn, V

    2016-04-01

    This work investigated the effects of feeding silage mixtures of a plant containing polyphenol oxidase (PPO; red clover [; RC]), a plant containing tannins (sainfoin [; SF]), and a grass species not containing these compounds (timothy [; T]) on ruminal and intramuscular (i.m.) fatty acids of lambs. Forty 4-mo-old castrated male Romane lambs, divided into 5 groups, received 1 of the following silages: 1) T (100%), 2) a binary mixture of timothy and tannin-containing sainfoin ( cv. Perly; 50:50 [T-SF]), 3) a binary mixture of timothy and PPO-containing red clover ( cv. Mervius; 50:50 [T-RC]), 4) a ternary mixture of timothy, sainfoin, and red clover containing both tannins and PPO (50:25:25, respectively [T-SF-RC]), and 5) a binary mixture of tannin-containing sainfoin and PPO-containing red clover (50:50 [SF-RC]). In the rumen digesta, the partial or total replacement of T with forage legumes was associated with greater concentrations of PUFA ( forage legumes in the silage favored the accumulation of 18:3 -3 ( Forage legumes decreased the -11 18:1 to 30% of T in rumen digesta ( Forage legumes decreased the total concentration of branched-chain fatty acids in the rumen digesta (on average, -28%; comparison with T. The dietary treatment tended to affect the proportion of MUFA ( = 0.081) and of PUFA ( = 0.079) in the i.m. fat of the LM, respectively, at the highest and lowest numerical value in the T group. The sum of -3 fatty acids was less in the T and T-SF groups compared with the mixture of legumes without T (SF-RC; comparison with lambs given T-RC, T-SF-RC, and SF-RC. Rumenic acid (-9 -11 CLA) was detected at a greater percentage in the LM from the animals fed the T silage compared with animals fed the T-SF-RC treatment ( = 0.004). Contrarily, -9 -12 -15 18:3 was found at a greater concentration in the muscle from lambs in the SF-RC treatment compared with lambs in the other treatments ( forage for growing lambs in terms of i.m. fatty acid composition.

  19. Effect of composition in the development of carbamazepine hot-melt extruded solid dispersions by application of mixture experimental design.

    Science.gov (United States)

    Djuris, Jelena; Ioannis, Nikolakakis; Ibric, Svetlana; Djuric, Zorica; Kachrimanis, Kyriakos

    2014-02-01

    This study investigates the application of hot-melt extrusion for the formulation of carbamazepine (CBZ) solid dispersions, using polyethyleneglycol-polyvinyl caprolactam-polyvinyl acetate grafted copolymer (Soluplus, BASF, Germany) and polyoxyethylene-polyoxypropylene block copolymer (Poloxamer 407). In agreement with the current Quality by Design principle, formulations of solid dispersions were prepared according to a D-optimal mixture experimental design, and the influence of formulation composition on the properties of the dispersions (CBZ heat of fusion and release rate) was estimated. Prepared solid dispersions were characterized using differential scanning calorimetry, attenuated total reflectance infrared spectroscopy and hot stage microscopy, as well as by determination of the dissolution rate of CBZ from the hot-melt extrudates. Solid dispersions of CBZ can be successfully prepared using the novel copolymer Soluplus. Inclusion of Poloxamer 407 as a plasticizer facilitated the processing and decreased the hardness of hot-melt extrudates. Regardless of their composition, all hot-melt extrudates displayed an improvement in the release rate compared to the pure CBZ, with formulations having the ratio of CBZ : Poloxamer 407 = 1 : 1 showing the highest increase in CBZ release rate. Interactions between the mixture components (CBZ and polymers), or quadratic effects of the components, play a significant role in overall influence on the CBZ release rate. © 2013 Royal Pharmaceutical Society.

  20. 1 composite mixture of TiO2 nanoparticles and nanotubes in dye

    Indian Academy of Sciences (India)

    Administrator

    Abstract. TiO2-based nanotubes (NTs), nanoparticles (NPs) and composite structural film (50% NP + 50% ... of faster electron injection ratio compared with other .... exist in this system. .... the open circuit voltage, Im the maximum current and.

  1. The effect of composition of mixture on rate of radiation initiation of chain reactions

    International Nuclear Information System (INIS)

    Poluehktov, V.A.; Begishev, I.R.; Podkhalyuzin, A.T.; Babkina, Eh.I.; Morozov, V.A.; Shapovalov, V.V.

    1977-01-01

    The effect of the composition of starting components on the rate of a number of chain liquid-phase reactions initiated by γ-quanta of Co 60 has been investigated at constant temperature and dosage rate. In regard to 1,1-difluoroethane chlorination, cyclohexene phosphorylation and adamantane alkylation with hexafluoropropylene reactions, abnormal effect of the reagent compositions on reaction rates has been discovered. The possible radical - starting molecule complexing reaction and molecular complexing from the starting components have been considered

  2. Pervaporation separation of ethanol-water mixtures using polyethylenimine composite membranes

    Science.gov (United States)

    Neidlinger, H.H.; Schissel, P.O.; Orth, R.A.

    1985-06-19

    Synthetic, organic, polymeric membranes were prepared from polyethylenimine for use with pervaporation apparatus in the separation of ethanol-water mixtures. The polymeric material was prepared in dilute aqueous solution and coated onto a polysulfone support film, from which excess polymeric material was subsequently removed. Cross-links were then generated by limited exposure to toluene-2,4-diisocyanate solution, after which the prepared membrane was heat-cured. The resulting membrane structures showed high selectivity in permeating ethanol or water over a wide range of feed concentrations. 2 tabs.

  3. Aspects regarding the tribological evaluation of sintered composites obtained from mixture of copper with carbon fibers

    Science.gov (United States)

    Caliman, R.

    2015-11-01

    This paper presents a study of the tribological properties of sintered composite materials made from combination of copper with short carbon fibers. Sintered composite materials are more effective if refer to specific properties per unit volume compared to conventional isotropic materials. Potential advantages of copper - carbon composite materials are: high resistance to breakage and high value ratios strength/density; resistance to high temperatures; low density and high resistance to wear; low or high friction coefficient. The sintered composite materials used in this research work are obtained combining different percentages of copper with short carbon fibres with iron and lead in order to investigate the variation of the friction behaviour. Varying the percentage of copper from 92,2% to 97,6% and the percentage of short carbon fibres from 7,8% to 2,4%, five different composite materials are obtained and tested. Friction tests are carried out, at room temperature, in dry conditions, on a pin-on-disc machine. The friction coefficient was measured using abrasive discs made from steel 4340 having the average hardness of 40 HRC, and sliding velocity of 0,6 m/sec. The main objective of this research work it was to identify a combination of materials with improved friction behaviour. The experimental results revealed that the force applied on the specimen during the tests, is playing a very important role regarding friction coefficient and also the wearing speed. Graphite particles are conveyed consistently inside the net, enhancing scraped spot safety and voltage drop over normal composite material. The static tests demonstrated that this new kind of sintered composite material has preferable electrical execution over previous brush material in the same conditions, and the element tests demonstrated that the temperature climb is not enormous when the brush with this new composite material is exchanged on with huge current and the surface scraped spot is littler amid

  4. The impact of co-firing sunflower husk pellets with coal in a boiler on the chemical composition of flue gas

    Directory of Open Access Journals (Sweden)

    Zajemska Monika

    2017-01-01

    The calculations showed that the most important influence on the composition of the flue gas from the co-firing process of coal with sunflower husk has a composition of biomass. It should be emphasized that the results of computer simulations obtained by the authors have an useful aspect and can be applied in practice, especially to the analysis of the mechanism of chloride corrosion which is possible to occur due to the chlorine content in the biomass. They may also be useful for evaluating the unburned hydrocarbons produced by combustion of rich mixtures (λ < 1.0.

  5. Chemical mixtures in untreated water from public-supply wells in the U.S. — Occurrence, composition, and potential toxicity

    International Nuclear Information System (INIS)

    Toccalino, Patricia L.; Norman, Julia E.; Scott, Jonathon C.

    2012-01-01

    Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. - Highlights: ► We assessed mixtures in untreated groundwater samples from public-supply wells. ► A screening

  6. Physicochemical effects of varying fuel composition on knock characteristics of natural gas mixtures

    NARCIS (Netherlands)

    Gersen, Sander; van Essen, Martijn; van Dijk, Gerco; Levinsky, Howard

    2014-01-01

    The physicochemical origins of how changes in fuel composition affect autoignition of the end gas, leading to engine knock, are analyzed for a natural gas engine. Experiments in a lean-burn, high-speed medium-BMEP gas engine are performed using a reference natural gas with systematically varied

  7. Formation and composition of adsorbates on hydrophobic carbon surfaces from aqueous laccase-maltodextrin mixture suspension

    Energy Technology Data Exchange (ETDEWEB)

    Corrales Ureña, Yendry Regina, E-mail: yendry386@hotmail.com [UNESP São Paulo State University, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, Bauru, São Paulo (Brazil); Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Wiener Strasse 12, 28359 Bremen (Germany); Lisboa-Filho, Paulo Noronha [UNESP São Paulo State University, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01, Bauru, São Paulo (Brazil); Szardenings, Michael [Fraunhofer Institute for Cell Therapy and Immunology IZI, Perlickstrasse 1, 04103 Leipzig (Germany); Gätjen, Linda; Noeske, Paul-Ludwig Michael; Rischka, Klaus [Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Wiener Strasse 12, 28359 Bremen (Germany)

    2016-11-01

    Highlights: • Less than 10 nm layer formed on carbon based materials composed by laccase and maltodextrin. • Improvement of the wettability of carbon based materials. • A protein-polysaccharide biofilm layer formation at solid liquid interface. • Stable layers formed under buffer and water rinsing. - Abstract: A robust procedure for the surface bio-functionalization of carbon surfaces was developed. It consists on the modification of carbon materials in contact with an aqueous suspension of the enzyme laccase from Trametes versicolor and the lyophilization agent maltodextrin, with the pH value adjusted close to the isoelectric point of the enzyme. We report in-situ investigations applying Quartz Crystal Microbalance with Dissipation (QCM-D) for carbon-coated sensor surfaces and, moreover, ex-situ measurements with static contact angle measurements, X-ray Photoelectron Spectroscopy (XPS) and Scanning Force Microscopy (SFM) for smooth Highly Oriented Pyrolytic Graphite (HOPG) substrates, for contact times between the enzyme formulation and the carbon material surface ranging from 20 s to 24 h. QCM-D studies reveals the formation of rigid layer of biomaterial, a few nanometers thin, which shows a strongly improved wettability of the substrate surface upon contact angle measurements. Following spectroscopic characterization, these layers are composed of mixtures of laccase and maltodextrin. The formation of these adsorbates is attributed to attractive interactions between laccase, the maltodextrin-based lyophilization agent and the hydrophobic carbon surfaces; a short-term contact between the aqueous laccase mixture suspension and HOPG surfaces is shown to merely result in de-wetting patterns influencing the results of contact angle measurements. The new enzyme-based surface modification of carbon-based materials is suggested to be applicable for the improvement of not only the wettability of low energy substrate surfaces with fluid formulations like coatings

  8. Determination of the composition of a mixture of polar substances by NMR; Determinacao da composicao de uma mistura de substancias polares por espectrometria de ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Antonio C.F.; Silva, Antonio J.R. da [Universidade Federal, Rio de Janeiro (Brazil). Nucleo de Pesquisas de Produtos Naturais

    1994-12-31

    This work describes the process of analysis of a mixture of polar compounds obtained from the extract of Phyllanthus tennellus, a plant known in Brazil as `quebra-pedra`, which is extensively used in Brazilian popular medicine. The methodology, which includes the use of chromatography and NMR, is described. The proposed composition of the mixture is presented. A discussion is presented concerning one component which could not be identified

  9. Bayesian decision and mixture models for AE monitoring of steel-concrete composite shear walls

    Science.gov (United States)

    Farhidzadeh, Alireza; Epackachi, Siamak; Salamone, Salvatore; Whittaker, Andrew S.

    2015-11-01

    This paper presents an approach based on an acoustic emission technique for the health monitoring of steel-concrete (SC) composite shear walls. SC composite walls consist of plain (unreinforced) concrete sandwiched between steel faceplates. Although the use of SC system construction has been studied extensively for nearly 20 years, little-to-no attention has been devoted to the development of structural health monitoring techniques for the inspection of damage of the concrete behind the steel plates. In this work an unsupervised pattern recognition algorithm based on probability theory is proposed to assess the soundness of the concrete infill, and eventually provide a diagnosis of the SC wall’s health. The approach is validated through an experimental study on a large-scale SC shear wall subjected to a displacement controlled reversed cyclic loading.

  10. Development of ceramic composites from mixture of alumina and ceramic precursor polymer poly (silsesquioxane))

    International Nuclear Information System (INIS)

    Machado, Glauson Aparecido Ferreira

    2009-01-01

    Processing of ceramics materials, by polymer precursors pyrolysis, has been intensively researched over the past decades, due to advantages that this path provides, such as: lower temperature process compared to conventional techniques; structure control at molecular level; synthesis possibility of a wide range of ceramic compounds; obtaining parts with dimensions of the final product etc. The active filler controlled polymer pyrolysis (AFCOP) process, enables the synthesis of ceramic composites, by reaction between added filler (oxides, metals, intermetallic etc.) and solid and gaseous products, from polymer decomposition. In this study, based on this process, samples of alumina, with addition of 10 and 20 mass% of poly silsesquioxane polymer precursor, were manufactured. These samples were pyrolyzed at 900 degree C and thermal treated at temperatures of 1100, 1300 and 1500 degree C. The samples were characterized for bulk density, porosity and hardness, after each stage of thermal treatment. Structural transformations were analyzed by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. Samples treated until 1300 degree C resulted in composites of alumina and silicon oxycarbide, while those treated at 1500 degree C, formed composites of mullite and alumina. The samples with 20% of polymer added started to density around 800 degree C and high retraction rate was observed at 1400 degree C. (author)

  11. Interfacial composition and stability of emulsions made with mixtures of commercial sodium caseinate and whey protein concentrate.

    Science.gov (United States)

    Ye, Aiqian

    2008-10-15

    The interfacial composition and the stability of oil-in-water emulsion droplets (30% soya oil, pH 7.0) made with mixtures of sodium caseinate and whey protein concentrate (WPC) (1:1 by protein weight) at various total protein concentrations were examined. The average volume-surface diameter (d32) and the total surface protein concentration of emulsion droplets were similar to those of emulsions made with both sodium caseinate alone and WPC alone. Whey proteins were adsorbed in preference to caseins at low protein concentrations (caseins were adsorbed in preference to whey proteins at high protein concentrations. The creaming stability of the emulsions decreased markedly as the total protein concentration of the system was increased above 2% (sodium caseinate >1%). This was attributed to depletion flocculation caused by the sodium caseinate in these emulsions. Whey proteins did not retard this instability in the emulsions made with mixtures of sodium caseinate and WPC. Copyright © 2008 Elsevier Ltd. All rights reserved.

  12. Air-Cured Fiber-Cement Composite Mixtures with Different Types of Cellulose Fibers

    Directory of Open Access Journals (Sweden)

    Ali Murat Soydan

    2018-01-01

    Full Text Available This present study was carried out to check the feasibility of different cellulose fibers obtained from cropped virgin cellulose, blenched eucalyptus, and araucaria pulps through different new environmentally friendly curing processes for fiber-cement production. The aim is to introduce the different sources of cellulose fibers with lower cost to produce the “fiber-cement without autoclave” (FCWA. The slurries used in the experiments contain approximately 8% wt. of cellulose. The influence of the waste marble powder addition to the cement mixture was also studied. The physical and mechanical properties of the products which were prepared with this method under different curing conditions were investigated. The mechanical properties of eucalyptus cellulose appear to offer the best combination, especially after longer air-cure cycles. The results showed that the production of FCWA is very economical by using waste marble powders. And moreover, two new types of cellulose fibers (eucalyptus and araucaria celluloses; EuC and ArC, resp., which provide a better density and packing in the fiber-cement leading to better modulus of rupture (MOR and modulus of elasticity (MOE values as virgin cellulose (ViC, are very usable for production of the fiber-cement in industrial scale.

  13. Improvement in methanol production by regulating the composition of synthetic gas mixture and raw biogas.

    Science.gov (United States)

    Patel, Sanjay K S; Mardina, Primata; Kim, Dongwook; Kim, Sang-Yong; Kalia, Vipin C; Kim, In-Won; Lee, Jung-Kul

    2016-10-01

    Raw biogas can be an alternative feedstock to pure methane (CH4) for methanol production. In this investigation, we evaluated the methanol production potential of Methylosinus sporium from raw biogas originated from an anaerobic digester. Furthermore, the roles of different gases in methanol production were investigated using synthetic gas mixtures of CH4, carbon dioxide (CO2), and hydrogen (H2). Maximum methanol production was 5.13, 4.35, 6.28, 7.16, 0.38, and 0.36mM from raw biogas, CH4:CO2, CH4:H2, CH4:CO2:H2, CO2, and CO2:H2, respectively. Supplementation of H2 into raw biogas increased methanol production up to 3.5-fold. Additionally, covalent immobilization of M. sporium on chitosan resulted in higher methanol production from raw biogas. This study provides a suitable approach to improve methanol production using low cost raw biogas as a feed containing high concentrations of H2S (0.13%). To our knowledge, this is the first report on methanol production from raw biogas, using immobilized cells of methanotrophs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Determination of composition of pozzolanic waste mixtures with optimized compressive strength

    Directory of Open Access Journals (Sweden)

    Nardi José Vidal

    2004-01-01

    Full Text Available The utilization of ceramic wastes with pozzolanic properties along with other compounds for obtaining new materials with cementating properties is an alternative for reducing the environmental pollution. The acceptance of these new products in the market demands minimal changes in mechanical properties according to its utilization. For a variable range of compositional intervals, attempts were made to establish limiting incorporation proportions that assure the achievement of minimum pre-established mechanical strength values in the final product. In this case minimum compressive strength value is 3,000 kPa. A simultaneous association of other properties is also possible.

  15. Composition, structure and properties of POPC–triolein mixtures. Evidence of triglyceride domains in phospholipid bilayers

    DEFF Research Database (Denmark)

    Duelund, Lars; Jensen, Grethe Vestergaard; Hannibal-Bach, Hans Kristian

    2013-01-01

    We have in this study investigated the composition, structure and spectroscopical properties of multilamellar vesicles composed of a phospholipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and up to 10mol% of triolein (TO), a triglyceride. We found in agreement with previous results...... as vesicular structures containing entrapped water. Bilayer structure of the membranes was supported by small angle X-ray scattering that showed the membranes to form a lamellar phase. Fluorescence spectroscopy with the polarity sensitive dye Nile red revealed, that the LF samples with more than 5mol......% TO contained pure TO domains. These observations are consistent with an earlier MD simulation study by us and our co-workers suggesting triglycerides to be located in lens shaped, blister-like domains between the two lipid bilayer leaflets (Khandelia et al. (2010) [26])....

  16. BROILER´S ROSS 308 MEAT CHEMICAL COMPOSITION AFTER ADDITION OF BEE POLLEN AS A SUPPLEMENT IN THEIR FEED MIXTURES

    Directory of Open Access Journals (Sweden)

    Peter Haščík

    2014-02-01

    Full Text Available The goal of this study was to evaluate the meat chemical composition of broiler chicken Ross 308. In the experiment, totally 200 one-day-old chicks were divided into 4 groups (n=50 for 42 days. Bee pollen was added to feed mixtures in doses 0; 2,500; 3,500 and 4,500 mg.kg-1. The findings found the moisture content of breast and thigh muscles were higher in the experimental groups compared to the control except E3 in thigh muscle, but in protein content were higher in the control group. On the other hand the fat content and energy value in the control group were higher comparison to experimental groups except E1. There are no significant differences (P ≥ 0.05 among the experimental groups. From the current study they conclude the bee pollen has a positive effect on the broiler Ross 308 chemical composition because the increase of moisture content and decrease the fat content which may be acceptable for several special human diets.

  17. Compositional, thermal and microstructural characterization of the Nopal (opuntia ficus indica), for addition in commercial cement mixtures

    Science.gov (United States)

    Hernández Carrillo, C. G.; Gómez-Cuaspud, J. A.; E Martínez Suarez, C.

    2017-12-01

    The Nopal (opuntia ficus indica) from remote times has contributed like food and additive product in prehispanic constructions; although it grows in all the Colombian territory is very little used and its contribution in mixtures of Colombian cement is unknown. In order to evaluate the hydration characteristics of Nopal, several Thermogravimetric Analysis (TGA) were performed to evaluate the optimal temperature of dehydration. Initially, the results show that around 175°C the weight loss is approximately 95%, this mass loss corresponds to the process of physical removal, suggesting that at least a remaining amount of 5% (w/w) has the ability to retain large amounts of water which is stored in the micro-structural deposits of Nopal. The evaluation by means Scanning Electron Microscopy (SEM), confirm that the whole cactus structure enables the water storage at cellular level. The results of infrared spectroscopy (FT-IR) and Energy Dispersive X-ray (EDX) analysis allowed the qualitative and semi-quantitative evaluation of the presence of functional groups and elemental chemical composition of Nopal respectively, mainly related with polysaccharide functional groups, which corresponds to 85% of the total composition. Other functional groups, are related with protein and mineral components. This found characteristics are relevant for the water retention in process that require the decrease of water consumption and the reinforcing of mechanical properties and durability, due to ability of Nopal mucilage to restore its hydration characteristics.

  18. Habitat Requirements of Breeding Black-Backed Woodpeckers (Picoides arcticus in Managed, Unburned Boreal Forest

    Directory of Open Access Journals (Sweden)

    Junior A. Tremblay

    2009-06-01

    Full Text Available We investigated home-range characteristics and habitat selection by Black-backed Woodpeckers (Picoides arcticus in an unburned, boreal forest landscape managed by mosaic harvesting in Quebec, Canada. Habitat selection by this species was specifically examined to determine home-range establishment and foraging activities. We hypothesized that Black-backed Woodpeckers would respond to harvesting by adjusting their home-range size as a function of the amount of dead wood available. Twenty-two birds were tracked using radiotelemetry, and reliable estimates of home-range size were obtained for seven breeding individuals (six males and one female. The average home-range size was 151.5 ± 18.8 ha (range: 100.4-256.4 ha. Our results indicate that this species establishes home ranges in areas where both open and forested habitats are available. However, during foraging activities, individuals preferentially selected areas dominated by old coniferous stands. The study also showed that the spatial distribution of preferred foraging habitat patches influenced space use, with home-range area increasing with the median distance between old coniferous habitat patches available within the landscape. Finally, these data show that Black-backed Woodpeckers may successfully breed in an unburned forest with at least 35 m3 • ha-1 of dead wood, of which 42% (15 m3 • ha-1 is represented by dead wood at the early decay stage.

  19. Structure and properties of mixtures based on long chain polyacrylate and 1-alcohol composites

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Haifeng, E-mail: haifeng.shi@gmail.com; Zhang, Lingjian; Li, Weiwei; Han, Xu; Zhang, Xingxiang

    2014-02-14

    A series of phase change materials (PCMs) based on long chain polyacrylate and 1-alcohol, i.e., poly (stearyl methacrylate) and 1-tetradecanol (PSMA/C14OH) were prepared through the solution-mixing method. Thermal energy storage capacity, thermal stability and morphology of PSMA/C14OH PCMs were characterized by Fourier transform infrared spectroscopy (FTIR), polarized optical microscopy (POM), field emission scanning electron microscopy (FE-SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC results demonstrated that the heat of fusion of PSMA/C14OH PCMs increased from 85.9 to 172.3 J g{sup −1} with the weight fraction of C14OH increasing from 20 to 80 wt%. And, the thermal stability also enhanced with PSMA weight. The spherulite (ca. 250 μm) in PSMA/C14OH composites containing 60 wt% C14OH proved the compatibility between PSMA and C14OH, indicating the cocrystallization behavior of alkyl side groups appeared. The cocrystallization behavior contributes the enhanced thermal stability of PSMA/C14OH PCMs, and it is suitable as the thermal energy storage materials in the future. - Highlights: • Heat storage capability of PSMA/C14OH PCMs increased with C14OH weight. • The spherulites exhibit the weight-dependence upon C14OH. • The thermal stability of PSMA/C14OH PCMs obviously improved.

  20. Effects of Composition and Calcination Temperature on Photocatalytic Evolution over from Glycerol and Water Mixture

    Directory of Open Access Journals (Sweden)

    Cancan Fan

    2012-01-01

    Full Text Available A series of sulfide coupled semiconductors supported on SiO2, (, was prepared by incipient wet impregnation method. The photocatalysts were characterized by XRD, XPS, TPR, and UV/Vis DRS. Characterization results show that the chemical actions between ZnS and CdS resulted in the formation of solid solutions on the surface of the support and the formation of them is affected by the molar ratio of ZnS/CdS and calcination temperature. Performance of photocatalysts was tested in the home made reactor under both UV light and solar-simulated light irradiation by detecting the rate of the photocatalytic H2 evolution from glycerol solution. The hydrogen production rates are related to the catalyst composition, surface structure, photoabsorption property, as well as the amount of solid solution. The maximum rate of hydrogen production, 550 μmol·h−1 under UV light irradiation and 210 μmol·h−1 under solar-simulated light irradiation, was obtained over Cd0.8Zn0.2S/SiO2 solid solution calcined at 723 K.

  1. Synthesis of geopolymer composites from a mixture of volcanic scoria and metakaolin

    Directory of Open Access Journals (Sweden)

    J.N.Y. Djobo

    2014-12-01

    Full Text Available The aim of this work is to valorize volcanic scoria by using them as starting material for geopolymers production. Nevertheless, volcanic scoria possesses low reactivity. Various amounts of metakaolin (5%, 10%, 15%, 20% and 25% were added into two volcanic scoria (ZD and ZG in order to improve their reactivity. Two alkaline solutions were used to activate the aluminosilicate materials. The starting materials were characterized by particle size distribution, specific surface area, chemical and mineralogical composition. The geopolymers were characterized by the setting time, XRD, FTIR, SEM and compressive strength. The results indicated that volcanic scoria have low specific surface area (2.3 m2/g for ZD, 15.7 m2/g for ZG, high average particle size (d50 = 13.08 μm and 10.68 μm for ZD and for ZG respectively and low glass phase contents. Metakaolin have a smaller average particle size (d50 = 9.95 μm and high specific surface (20.5 m2/g. The compressive strength of geopolymers increased in the ranges of 23–68 MPa and 39–64 MPa for geopolymers from ZD–MK and ZG–MK respectively. This study shows that despite the low reactivity of volcanic scoria it can still be used to synthesize geopolymers with good physical and mechanical properties.

  2. Evaluation of an unsteady flamelet progress variable model for autoignition and flame development in compositionally stratified mixtures

    Science.gov (United States)

    Mukhopadhyay, Saumyadip; Abraham, John

    2012-07-01

    The unsteady flamelet progress variable (UFPV) model has been proposed by Pitsch and Ihme ["An unsteady/flamelet progress variable method for LES of nonpremixed turbulent combustion," AIAA Paper No. 2005-557, 2005] for modeling the averaged/filtered chemistry source terms in Reynolds averaged simulations and large eddy simulations of reacting non-premixed combustion. In the UFPV model, a look-up table of source terms is generated as a function of mixture fraction Z, scalar dissipation rate χ, and progress variable C by solving the unsteady flamelet equations. The assumption is that the unsteady flamelet represents the evolution of the reacting mixing layer in the non-premixed flame. We assess the accuracy of the model in predicting autoignition and flame development in compositionally stratified n-heptane/air mixtures using direct numerical simulations (DNS). The focus in this work is primarily on the assessment of accuracy of the probability density functions (PDFs) employed for obtaining averaged source terms. The performance of commonly employed presumed functions, such as the dirac-delta distribution function, the β distribution function, and statistically most likely distribution (SMLD) approach in approximating the shapes of the PDFs of the reactive and the conserved scalars is evaluated. For unimodal distributions, it is observed that functions that need two-moment information, e.g., the β distribution function and the SMLD approach with two-moment closure, are able to reasonably approximate the actual PDF. As the distribution becomes multimodal, higher moment information is required. Differences are observed between the ignition trends obtained from DNS and those predicted by the look-up table, especially for smaller gradients where the flamelet assumption becomes less applicable. The formulation assumes that the shape of the χ(Z) profile can be modeled by an error function which remains unchanged in the presence of heat release. We show that this

  3. Phase-field modeling of mixing/demixing of regular binary mixtures with a composition-dependent viscosity

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2017-04-01

    We simulate the mixing (demixing) process of a quiescent binary liquid mixture with a composition-dependent viscosity which is instantaneously brought from the two-phase (one-phase) to the one-phase (two-phase) region of its phase diagram. Our theoretical approach follows a standard diffuse-interface model of partially miscible regular binary mixtures wherein convection and diffusion are coupled via a nonequilibrium capillary force, expressing the tendency of the phase-separating system to minimize its free energy. Based on 2D simulation results, we discuss the influence of viscosity ratio on basic statistics of the mixing (segregation) process triggered by a rapid heating (quench), assuming that the ratio of capillary to viscous forces (a.k.a. the fluidity coefficient) is large. We show that, for a phase-separating system, at a fixed value of the fluidity coefficient (with the continuous phase viscosity taken as a reference), the separation depth and the characteristic length of single-phase microdomains decrease monotonically for increasing values of the viscosity of the dispersed phase. This variation, however, is quite small, in agreement with experimental results. On the other hand, as one might expect, at a fixed viscosity of the dispersed phase both of the above statistics increase monotonically as the viscosity of the continuous phase decreases. Finally, we show that for a mixing system the attainment of a single-phase equilibrium state by coalescence and diffusion is retarded by an increase in the viscosity ratio at a fixed fluidity for the dispersed phase. In fact, for large enough values of the viscosity ratio, a thin film of the continuous phase becomes apparent when two drops of the minority phase approach each other, which further retards coalescence.

  4. Current perspectives of bio-ceramic technology in endodontics: calcium enriched mixture cement - review of its composition, properties and applications

    Science.gov (United States)

    Nawal, Ruchika Roongta; Talwar, Sangeeta; Verma, Mahesh

    2015-01-01

    Advancements in bio-ceramic technology has revolutionised endodontic material science by enhancing the treatment outcome for patients. This class of dental materials conciliates excellent biocompatibility with high osseoconductivity that render them ideal for endodontic care. Few recently introduced bio-ceramic materials have shown considerable clinical success over their early generations in terms of good handling characteristics. Calcium enriched mixture (CEM) cement, Endosequence sealer, and root repair materials, Biodentine and BioAggregate are the new classes of bio-ceramic materials. The aim of this literature review is to present investigations regarding properties and applications of CEM cement in endodontics. A review of the existing literature was performed by using electronic and hand searching methods for CEM cement from January 2006 to December 2013. CEM cement has a different chemical composition from that of mineral trioxide aggregate (MTA) but has similar clinical applications. It combines the biocompatibility of MTA with more efficient characteristics, such as significantly shorter setting time, good handling characteristics, no staining of tooth and effective seal against bacterial leakage. PMID:25671207

  5. Induced liquid-crystalline ordering in solutions of stiff and flexible amphiphilic macromolecules: Effect of mixture composition

    International Nuclear Information System (INIS)

    Glagolev, Mikhail K.; Vasilevskaya, Valentina V.; Khokhlov, Alexei R.

    2016-01-01

    Impact of mixture composition on self-organization in concentrated solutions of stiff helical and flexible macromolecules was studied by means of molecular dynamics simulation. The macromolecules were composed of identical amphiphilic monomer units but a fraction f of macromolecules had stiff helical backbones and the remaining chains were flexible. In poor solvents the compacted flexible macromolecules coexist with bundles or filament clusters from few intertwined stiff helical macromolecules. The increase of relative content f of helical macromolecules leads to increase of the length of helical clusters, to alignment of clusters with each other, and then to liquid-crystalline-like ordering along a single direction. The formation of filament clusters causes segregation of helical and flexible macromolecules and the alignment of the filaments induces effective liquid-like ordering of flexible macromolecules. A visual analysis and calculation of order parameter relaying the anisotropy of diffraction allow concluding that transition from disordered to liquid-crystalline state proceeds sharply at relatively low content of stiff components.

  6. How is the chlorophyll count affected by burned and unburned marsh areas?

    Science.gov (United States)

    Kendrick, C.

    2017-12-01

    Does marsh burnings, either man made or natural, hinder or help Louisiana's vitally important coastal plant life? Does the carbon produced from the fires have a negative effect on the chlorophyll count of these precious living protective barriers? Or does it help contribute to raising the plants chlorophyll count? Along Louisiana's Gulf Coast, marsh burnings are conducted every 2-4 years to destroy some of the Spartina patens. Fires and smoke may have an effect on the chlorophyll count of the plants found in Louisiana's marshes. Peat burns, root burns, and cover burns are the three types of marsh fires. These burns can be either man made or started by natural causes. Peat burns occur when the soil is dry due to a drained marsh. Root burns occur when plant roots are burned without the soil being consumed. Cover burns occur when several centimeters of water covers the soil. Cover burns are often used by Wildlife and Fisheries personnel to promote preferred plant food growth like Scirpus olneyi rather than the dominant Spartina patens. Our project was conducted by testing marsh plants and obtaining chlorophyll count of both a burned (cover burn) and an unburned area. Approximately one year after the burn, in August 2015, we tested the burned area's site. We retested the same site in December 2016. The results from our testing showed that there was a slightly higher chlorophyll count in the burned area. The chlorophyll count average from the two testing days was 33.5 in the burned area and 30.15 in the unburned area. Our hypothesis was that the chlorophyll content of "controlled" burned wetland areas will have a higher amount than the "no" burn area. The experiment results supported this hypothesis by showing an increase of 3.35 average in the burned area.

  7. Planar LIF observation of unburned fuel escaping the upper ring-land crevice in an SI engine

    Energy Technology Data Exchange (ETDEWEB)

    Green, R.M.; Cloutman, L.D.

    1997-01-01

    PLIF has been used to observe the in-cylinder transport of unburned fuel that, while trapped in the ring-land and ring-groove crevices, survives combustion in the propagating flame. Away from the top-ring gap, we detect a wall-jet comprised of unburned charge exiting the top ring-land crevice opening. At the location of the top-ring gap, we observed unburned fuel lying in the cool boundary layer along the cylinder wall during the later stages of the expansion stroke. This layer is scraped into the roll-up vortex during the exhaust stroke. These data lead us to conclude that away from the end gap, unburned, high pressure charge, trapped between the two compression rings escapes as a wall jet after ring-reversal near the bottom center. Conversely, at the ring gap, when the cylinder pressure drops below the pressure between the compression rings, the trapped charge escapes through the gap and forms a thin layer on the cylinder wall.

  8. Relationship between composition of mixture charged and that in circulation in an auto refrigerant cascade and a J-T refrigerator operating in liquid refrigerant supply mode

    Science.gov (United States)

    Sreenivas, Bura; Nayak, H. Gurudath; Venkatarathnam, G.

    2017-01-01

    The composition of the refrigerant mixture in circulation during steady state operation of J-T and allied refrigerators is not the same as that charged due to liquid hold up in the heat exchangers and phase separators, as well as the differential solubility of different refrigerant components in the compressor lubricating oil. The performance of refrigerators/liquefiers operating on mixed refrigerant cycles is dependent on the mixture composition. It is therefore important to charge the right mixture that results in an optimum composition in circulation during steady state operation. The relationship between the charged and circulating composition has been experimentally studied in a J-T refrigerator operating in the liquid refrigerant supply (LRS) mode and an auto refrigerant cascade refrigerator (with a phase separator) operating in the gas refrigerant supply (GRS) mode. The results of the study are presented in this work. The results show that the method presented earlier for J-T refrigerators operating in GRS mode is also applicable in the case of refrigerators studied in this work.

  9. Evaluation of the phase composition of (NH4)2SO4 + (NH4)H2PO4 mixtures by X-ray diffractometry

    International Nuclear Information System (INIS)

    Ortiz, Angel L.; Cumbrera, Francisco L.; Perez, Jose; Vas, Beatriz del; Perez, Eduardo

    2009-01-01

    The phase composition of standard (NH 4 ) 2 SO 4 + (NH 4 )H 2 PO 4 mixtures was investigated by X-ray diffractometry (XRD) using the internal-standard, reference-intensity-ratio, and Rietveld methods. It was found that the Rietveld method yields the most accurate phase-composition measurements, with an average error of ∼2 wt.%. It was also found that the internal-standard method is only effective in determining the phase composition if the calibration curve for (NH 4 )H 2 PO 4 is used, giving an average error of ∼6.5 wt.%. On the contrary, the internal-standard method with the calibration curve of the (NH 4 ) 2 SO 4 phase and the reference-intensity-ratio method are not valid. The inappropriateness of these two methods was attributed to graininess in the (NH 4 ) 2 SO 4 phase, with the attendant deviation of its diffracted intensities from the theoretical values. Direct scanning electron microscopy observations of the morphology of the powder particles in the mixtures showed clear evidence of the large agglomerates formed because the individual powder particles are partially sintered together during milling, thus corroborating the graininess determined by the XRD analyses. Finally, the implications of the present study for the quantitative phase-composition analysis of (NH 4 ) 2 SO 4 + (NH 4 )H 2 PO 4 mixtures, which are of great technological importance for the fire prevention industry, are discussed.

  10. Investigating the Effect of the Binary Mixtures Composition of Noble Gases on Their Thermodynamic and Transport Properties

    Directory of Open Access Journals (Sweden)

    S. A. Burtsev

    2015-01-01

    Full Text Available The paper presents possible application fields of the binary noble gas mixtures with low Prandtl numbers. It shows that it is expedient to select these mixtures as the working fluids for closed Brayton cycle gas-turbine installations, thermo-acoustic engines and for the gas dynamic energy separation device (Leontiev tube. As follows from the analysis, He-Ar, He-Kr, and HeXe mixtures have proven to be the most attractive choice. The paper has analyzed the calculation results for coefficient of dynamic viscosity, coefficient of thermal conductivity, and for heat capacity at constant pressure for the given mixtures in terms of mixture molecular weights at pressures of 2MPa and 7MPa and temperatures of 400 and 1200°K. According to data of experiments and calculations available in public sources published by another authors, the results are verified. It was found that at constant pressure within the examined range of parameters (i.e. pressure, temperature, mixture molecular weight the obtained heat capacity values are in good agreement with the values of the verification data. In calculating dynamic viscosity coefficient for any pressure and temperature the utilized technique provides results for He-Ar and He-Kr mixtures within the entire range of the molecular weights, which are, essentially, as good as shown by international verification techniques. However, at high pressures and low temperatures for He-Xe mixture with molecular weights close to the pure Xe the divergence was found to be as high as 25 % while for other parameter intervals under consideration and with the same mixture the difference does not exceed 10 %. A good agreement with the verification data is observed for the values of a thermal conductivity coefficient of He-Ar and He-Kr mixtures for any value of parameters, while for He-Xe mixture with molecular weights close to 60 g/mole independently of pressure the divergence can reach 30 % for 1200°K and 20 % for 400°K. It is shown

  11. Compositional dependence of absorption coefficient and band-gap for Nb2O5-SiO2 mixture thin films

    International Nuclear Information System (INIS)

    Sancho-Parramon, Jordi; Janicki, Vesna; Zorc, Hrvoje

    2008-01-01

    The absorption coefficient of composite films consisting of niobia (Nb 2 O 5 ) and silica (SiO 2 ) mixtures is studied for photon energies around the band gap. The films were deposited by co-evaporation and their composition was varied by changing the ratio of deposition rates of the two materials. Both, as-deposited and thermally annealed films were characterized by different techniques: the absorption coefficient was determined by spectrophotometric measurements and the structural properties were investigated using infrared spectroscopy, transmission electron microscopy and X-ray diffraction. The correlation between the variations of absorption properties and film composition and structure is established. The absorption coefficients determined experimentally are compared with the results derived from effective medium theories in order to evaluate the suitability of these theories for the studied composites

  12. Optimization of glibenclamide tablet composition through the combined use of differential scanning calorimetry and D-optimal mixture experimental design.

    Science.gov (United States)

    Mura, P; Furlanetto, S; Cirri, M; Maestrelli, F; Marras, A M; Pinzauti, S

    2005-02-07

    A systematic analysis of the influence of different proportions of excipients on the stability of a solid dosage form was carried out. In particular, a d-optimal mixture experimental design was applied for the evaluation of glibenclamide compatibility in tablet formulations, consisting of four classic excipients (natrosol as binding agent, stearic acid as lubricant, sorbitol as diluent and cross-linked polyvinylpyrrolidone as disintegrant). The goal was to find the mixture component proportions which correspond to the optimal drug melting parameters, i.e. its maximum stability, using differential scanning calorimetry (DSC) to quickly obtain information about possible interactions among the formulation components. The absolute value of the difference between the melting peak temperature of pure drug endotherm and that in each analysed mixture and the absolute value of the difference between the enthalpy of the pure glibenclamide melting peak and that of its melting peak in the different analyzed mixtures, were chosen as indexes of the drug-excipient interaction degree.

  13. Modeling unburned hydrocarbon formation due to absorption/desorption processes into the wall oil film

    International Nuclear Information System (INIS)

    Shih, L.K.; Assanis, D.N.

    1992-01-01

    This paper reports that as a result of continuing air pollution problems, very stringent regulations are being enforced to control emissions of unburned hydrocarbons (HC) from premixed-charge, spark-ignition engines. A number of attempts have been reported on modeling sources of HC emissions using various analytical tools. Over the past decade, the development of multi-dimensional reacting flow codes has advanced considerably. Perhaps the most widely used multi-dimensional engine simulation code is KIVA-II, which was developed at Lost Alamos National Laboratory. The ability to deal with moving boundary conditions caused by the piston movement is built in this code. This code also includes models for turbulent fluid flow, turbulent interaction between spray drops and gas, heat transfer, chemical reaction, and fuel spray. A standard k-ε turbulence model is used for gas flow. The fuel spray model is based on the stochastic particle technique, and includes sub-models for droplet injection, breakup, collision and coalescence, and evaporation

  14. Applied Gaussian Process in Optimizing Unburned Carbon Content in Fly Ash for Boiler Combustion

    Directory of Open Access Journals (Sweden)

    Chunlin Wang

    2017-01-01

    Full Text Available Recently, Gaussian Process (GP has attracted generous attention from industry. This article focuses on the application of coal fired boiler combustion and uses GP to design a strategy for reducing Unburned Carbon Content in Fly Ash (UCC-FA which is the most important indicator of boiler combustion efficiency. With getting rid of the complicated physical mechanisms, building a data-driven model as GP is an effective way for the proposed issue. Firstly, GP is used to model the relationship between the UCC-FA and boiler combustion operation parameters. The hyperparameters of GP model are optimized via Genetic Algorithm (GA. Then, served as the objective of another GA framework, the predicted UCC-FA from GP model is utilized in searching the optimal operation plan for the boiler combustion. Based on 670 sets of real data from a high capacity tangentially fired boiler, two GP models with 21 and 13 inputs, respectively, are developed. In the experimental results, the model with 21 inputs provides better prediction performance than that of the other. Choosing the results from 21-input model, the UCC-FA decreases from 2.7% to 1.7% via optimizing some of the operational parameters, which is a reasonable achievement for the boiler combustion.

  15. Habitat suitability and nest survival of white-headed woodpeckers in unburned forests of Oregon

    Science.gov (United States)

    Hollenbeck, Jeff P.; Saab, Victoria A.; Frenzel, Richard W.

    2011-01-01

    We evaluated habitat suitability and nest survival of breeding white-headed woodpeckers (Picoides albolarvatus) in unburned forests of central Oregon, USA. Daily nest-survival rate was positively related to maximum daily temperature during the nest interval and to density of large-diameter trees surrounding the nest tree. We developed a niche-based habitat suitability model (partitioned Mahalanobis distance) for nesting white-headed woodpeckers using remotely sensed data. Along with low elevation, high density of large trees, and low slope, our habitat suitability model suggested that interspersion–juxtaposition of low- and high-canopy cover ponderosa pine (Pinus ponderosa) patches was important for nest-site suitability. Cross-validation suggested the model performed adequately for management planning at a scale >1 ha. Evaluation of mapped habitat suitability index (HSI) suggested that the maximum predictive gain (HSI = 0.36), where the number of nest locations are maximized in the smallest proportion of the modeled landscape, provided an objective initial threshold for identification of suitable habitat. However, managers can choose the threshold HSI most appropriate for their purposes (e.g., locating regions of low–moderate suitability that have potential for habitat restoration). Consequently, our habitat suitability model may be useful for managing dry coniferous forests for white-headed woodpeckers in central Oregon; however, model validation is necessary before our model could be applied to other locations.

  16. Capillary Condensation of Binary and Ternary Mixtures of n-Pentane-Isopentane-CO2 in Nanopores: An Experimental Study on the Effects of Composition and Equilibrium.

    Science.gov (United States)

    Barsotti, Elizabeth; Saraji, Soheil; Tan, Sugata P; Piri, Mohammad

    2018-02-06

    Confinement in nanopores can significantly impact the chemical and physical behavior of fluids. While some quantitative understanding is available for how pure fluids behave in nanopores, there is little such insight for mixtures. This study aims to shed light on how nanoporosity impacts the phase behavior and composition of confined mixtures through comparison of the effects of static and dynamic equilibrium on experimentally measured isotherms and chromatographic analysis of the experimental fluids. To this end, a novel gravimetric apparatus is introduced and validated. Unlike apparatuses that have been previously used to study the confinement-induced phase behavior of fluids, this apparatus employs a gravimetric technique capable of discerning phase transitions in a wide variety of nanoporous media under both static and dynamic conditions. The apparatus was successfully validated against data in the literature for pure carbon dioxide and n-pentane. Then, isotherms were generated for binary mixtures of carbon dioxide and n-pentane using static and flow-through methods. Finally, two ternary mixtures of carbon dioxide, n-pentane, and isopentane were measured using the static method. While the equilibrium time was found important for determination of confined phase transitions, flow rate in the dynamic method was not found to affect the confined phase behavior. For all measurements, the results indicate qualitative transferability of the bulk phase behavior to the confined fluid.

  17. Characteristic of bioplastic’s physical and mechanical (Study on Tapioca Concentration and Composition Mixture of Plasticizer

    Directory of Open Access Journals (Sweden)

    Bambang Admadi Harsojuwono

    2016-03-01

    Full Text Available This study aims to (1 the effect of the concentration of starch and  ratio mixture of plasticizer to the physical and mechanical characteristics of bioplastics (2 determine the concentration of starch and plasticizer RATIO mixture  that results in physical and mechanical characteristics of bio plastics best. The experiment was conducted using a factorial randomized block design. The first factor is the concentration of tapioca consisting of 3 levels 4%, 5% and 6% (w / w. The second factor is the   mixture plasticizer ratio  of glycerol and sorbitol   consisting of 5 levels ie (100: 0%, (95: 5%, (90:10%, (85:15%, (80:20% b / b. Each combination of treatments classified into 2 time  processing bio plastics, so there are 30 experimental units. Variables observed water content, elongation at break, tensile strength and Young's modulus . The data obtained were analyzed of variant and  test of Duncan's. The results showed that the concentration of tapioca and  mixture plasticizer had no effect on water content but significant effect on the elongation at break, tensile strength and Young's modulus. The concentration of starch 6% with a ratio of mixture of plasticizers glycerol: sorbitol ( 100: 0 produces the best characteristics of bioplastics with water content of 3.98%, elongation at break of 18.75%, the tensile strength of 930 MPa and a Young's modulus of 50 MPa.

  18. Effect of temperature and composition on the surface tension and surface properties of binary mixtures containing DMSO and short chain alcohols

    International Nuclear Information System (INIS)

    Bagheri, Ahmad; Fazli, Mostafa; Bakhshaei, Malihe

    2016-01-01

    Highlights: • Surface tension of DMSO + alcohol (methanol, ethanol and isopropanol) at various temperatures was measured. • The surface tension data of binary mixtures were correlated with four equations. • Intermolecular interaction of DMSO with alcohol was discussed. • The surface mole fraction of alcohol increase with increasing the length of alcohol chain. - Abstract: Surface tension of binary mixtures of methanol, ethanol and isopropanol with DMSO (dimethyl sulfoxide) was measured over the whole range of composition at atmospheric pressure of 82.5 kPa within the temperatures between (298.15 and 328.15) K. The experimental measurements were used to calculate in surface tension deviations (Δσ). The sign of Δσ for all temperatures is negative (except of methanol/DMSO system) because of the factors of hydrogen bonding and dipole–dipole interactions in the DMSO-alcohol systems. Surface tension values of the binary systems were correlated with FLW, MS, RK and LWW models. The mean standard deviation obtained from the comparison of experimental and calculated surface tension values for binary systems with three models (FLW, MS and RK) at various temperatures is less than 0.83. Also, the results of the LWW model were used to account for the interaction energy between alcohols and DMSO in binary mixtures. The temperature dependence of σ (surface tension) at fixed composition of solutions was used to estimate surface enthalpy, H s , and surface entropy, S s . The results obtained show that the values of the thermodynamic parameters for alcohol/DMSO mixtures decrease with increasing alkyl chain length of alcohol. Finally, the results are discussed in terms of surface mole fraction and lyophobicity using the extended Langmuir (EL) isotherm.

  19. Effects of the cellulose, xylan and lignin constituents on biomass pyrolysis characteristics and bio-oil composition using the Simplex Lattice Mixture Design method

    International Nuclear Information System (INIS)

    Fan, Yongsheng; Cai, Yixi; Li, Xiaohua; Jiao, Lihua; Xia, Jisheng; Deng, Xiuli

    2017-01-01

    Highlights: • Simplex Lattice Mixture Design was firstly applied to study biomass pyrolysis process. • Interactions between the constituents had effects on the biomass pyrolysis behavior. • Biomass pyrolysis behavior can be predicted based on the ratios of three constituents. • Bio-oil composition was affected by the constituents and their pyrolysis products. - Abstract: In order to clarify the relationships between biomass pyrolysis mechanism and its main constituents. The effects of main constituents on biomass pyrolysis characteristics were firstly determined by thermo-gravimetric analysis based on the Simplex Lattice Mixture Design to investigate that whether the prediction of the pyrolysis behavior of a certain lignocellulosic biomass is possible when its main constituent contents are known. The results showed that there are constituent interactions in the pyrolysis process, which can be intuitively reflected through the change laws of kinetics parameters. The mathematical models for calculating kinetics values were established, and the models were proved to be valid for predicting lignocellulosic biomass pyrolysis behavior. In addition, the effects of biomass constituents on bio-oil compositions were explored by subsequent vacuum pyrolysis experiments. The xylan pyrolysis had a certain inhibitory effect on the pyrolysis of cellulose, and the pyrolysis products of lignin might promote the further decomposition of sugars from cellulose pyrolysis, while the interaction between xylan and lignin had a little effect on the bio-oil composition.

  20. Graphene/TiO2/ZSM-5 composites synthesized by mixture design were used for photocatalytic degradation of oxytetracycline under visible light: Mechanism and biotoxicity

    Science.gov (United States)

    Hu, Xin-Yan; Zhou, Kefu; Chen, Bor-Yann; Chang, Chang-Tang

    2016-01-01

    This first-attempt study revealed mixture design of experiments to obtain the most promising composites of TiO2 loaded on zeolite and graphene for maximal photocatalytic degradation of oxytetracycline (OTC). The optimal weight ratio of graphene, titanium dioxide (TiO2), and zeolite was 1:8:1 determined via experimental design of simplex lattice mixture. The composite material was characterized by XRD, UV-vis, TEM and EDS analysis. The findings showed the composite material had a higher stability and a stronger absorption of the visible light. In addition, it was uniformly dispersed with promising adsorption characteristics. OTC was used as model toxicant to evaluate the photodegradation efficiency of the GTZ (1:8:1). At optimal operating conditions (i.e., pH 7 and 25 °C), complete degradation (ca. 100%) was achieved in 180 min. The biotoxicity of the degraded intermediates of OTC on cell growth of Escherichia coli DH5α were also assayed. After 180 min photocatalytic treatment, OTC solution treated by GTZ (1:8:1) showed insignificant biotoxicity to receptor DH5α cells. Furthermore, EDTA (hole scavengers) and t-BuOH (radical scavengers) were used to detect the main active oxidative species in the system. The results showed that the holes are the main oxidation species in the photocatalytic process.

  1. The impact of donor characteristics on the immune cell composition of mixture allografts of granulocyte-colony-stimulating factor-mobilized marrow harvests and peripheral blood harvests.

    Science.gov (United States)

    Wang, Yu-Tong; Zhao, Xiang-Yu; Zhao, Xiao-Su; Xu, Lan-Ping; Zhang, Xiao-Hui; Wang, Yu; Liu, Kai-Yan; Chang, Ying-Jun; Huang, Xiao-Jun

    2015-12-01

    The association of donor characteristics with immune cell composition in allografts remains poorly understood. In this retrospective study, the effects of donor characteristics on immune cell composition in allografts were investigated. The correlations of donor characteristics with the immune cell composition in mixture allografts of granulocyte-colony-stimulating factor-mobilized marrow harvests and peripheral blood harvests of 390 healthy donors (male, 240; female, 150; median age, 40 years old) were analyzed. The median doses of CD3+ T cells, CD4+ T cells, CD8+ T cells, CD3+CD4-CD8- T cells, and monocytes in mixture allografts were 160.57 × 10(6), 89.29 × 10(6), 56.16 × 10(6), 10.87 × 10(6), and 137.94 × 10(6)/kg, respectively. Multivariate analysis showed that younger donor age was associated with a higher dose of CD3+ T cells (p = 0.006), CD3+CD8+ T cells (p donor weight with CD3+ T cells (p blood lymphocyte pre-peripheral blood apheresis was correlated with the yield of CD3+ T cells (p blood monocyte count before marrow harvest predicted the monocyte dose (p = 0.002). The results suggested that older and overweight donors should not be chosen. The monocyte and lymphocyte counts before harvest could predict the yield of immune cells in allografts. © 2015 AABB.

  2. Chemical Composition Based Aerosol Optical Properties According to Size Distribution and Mixture Types during Smog and Asian Dust Events in Seoul, Korea

    Science.gov (United States)

    Jung, Chang Hoon; Lee, Ji Yi; Um, Junshik; Lee, Seung Soo; Kim, Yong Pyo

    2018-02-01

    This study investigated the optical properties of aerosols involved in different meteorological events, including smog and Asian dust days. Carbonaceous components and inorganic species were measured in Seoul, Korea between 25 and 31 March 2012. Based on the measurements, the optical properties of aerosols were calculated by considering composition, size distribution, and mixing state of aerosols. To represent polydisperse size distributions of aerosols, a lognormal size distribution with a wide range of geometric mean diameters and geometric standard deviations was used. For the optical property calculations, the Mie theory was used to compute single-scattering properties of aerosol particles with varying size and composition. Analysis of the sampled data showed that the water-soluble components of organic matter increased on smog days, whereas crustal elements increased on dust days. The water content significantly influenced the optical properties of aerosols during the smog days as a result of high relative humidity and an increase in the water-soluble component. The absorption coefficients depended on the aerosol mixture type and the aerosol size distributions. Therefore, to improve our knowledge on radiative impacts of aerosols, especially the regional impacts of aerosols in East Asia, accurate measurements of aerosols, such as size distribution, composition, and mixture type, under different meteorological conditions are required.

  3. THE EFFECT OF ADDING WHOLE WHEAT GRAIN TO FEED MIXTURE ON SLAUGHTER YIELD AND CARCASS COMPOSITION IN GAME PHEASANTS

    Directory of Open Access Journals (Sweden)

    DARIUSZ KOKOSZYŃSKI

    2009-06-01

    Full Text Available The mean body weight of pheasant cocks (1226 g and hens (946.9 g receiving feed mixtures was lower than that of birds fed diets with wheat (♂ 1421.4 g, ♀ 953.2 g. The dressing percentage of both sexes pheasants fed wheat grain also (69.9% was only 0.3% lower than in birds receiving feed mixtures only (70.2%. The carcasses of birds (♂♀ fed the diet with whole wheat grain contained more breast muscles (251.2 g, leg muscles (198.8 g and other carcass components. The carcass percentage of breast muscles, leg muscles, wings and skin with fat was lower, and that of remainders of carcass higher in pheasants receiving wheat grain. In addition, the carcasses of pheasants (♂♀ fed the wheat diets were characterized by a higher weight of meat and fat and lower carcass meat and fat percentage.

  4. OPTIMIZED FUEL INJECTOR DESIGN FOR MAXIMUM IN-FURNACE NOx REDUCTION AND MINIMUM UNBURNED CARBON

    Energy Technology Data Exchange (ETDEWEB)

    SAROFIM, A F; LISAUSKAS, R; RILEY, D; EDDINGS, E G; BROUWER, J; KLEWICKI, J P; DAVIS, K A; BOCKELIE, M J; HEAP, M P; PERSHING, D

    1998-01-01

    Reaction Engineering International (REI) has established a project team of experts to develop a technology for combustion systems which will minimize NO x emissions and minimize carbon in the fly ash. This much need technology will allow users to meet environmental compliance and produce a saleable by-product. This study is concerned with the NO x control technology of choice for pulverized coal fired boilers,"in-furnace NOx control," which includes: staged low-NOx burners, reburning, selective non-catalytic reduction (SNCR) and hybrid approaches (e.g., reburning with SNCR). The program has two primary objectives: 1) To improve the performance of "in-furnace" NOx control, processes. 2) To devise new, or improve existing, approaches for maximum "in-furnace" NOx control and minimum unburned carbon. The program involves: 1) fundamental studies at laboratory- and bench-scale to define NO reduction mechanisms in flames and reburning jets; 2) laboratory experiments and computer modeling to improve our two-phase mixing predictive capability; 3) evaluation of commercial low-NOx burner fuel injectors to develop improved designs, and 4) demonstration of coal injectors for reburning and low-NOx burners at commercial scale. The specific objectives of the two-phase program are to: 1 Conduct research to better understand the interaction of heterogeneous chemistry and two phase mixing on NO reduction processes in pulverized coal combustion. 2 Improve our ability to predict combusting coal jets by verifying two phase mixing models under conditions that simulate the near field of low-NOx burners. 3 Determine the limits on NO control by in-furnace NOx control technologies as a function of furnace design and coal type. 5 Develop and demonstrate improved coal injector designs for commercial low-NOx burners and coal reburning systems. 6 Modify the char burnout model in REI's coal

  5. Graphene/TiO{sub 2}/ZSM-5 composites synthesized by mixture design were used for photocatalytic degradation of oxytetracycline under visible light: Mechanism and biotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xin-Yan; Zhou, Kefu [College of the Environment and Ecology, Xiamen University, Xiamen (China); Chen, Bor-Yann, E-mail: boryannchen@yahoo.com.tw [Department of Chemical and Materials Engineering, National I-Lan University, Ilan, Taiwan (China); Chang, Chang-Tang, E-mail: ctchang73222@gmail.com [Department of Environmental Engineering, National I-Lan University, Ilan, Taiwan (China)

    2016-01-30

    Graphical abstract: The mechanism of OTC degradation can be described as follows. At first, the OTC molecule was adsorbed onto the surface of GTZ material. The conduction band electron (e{sup −}) and valence band holes (h{sup +}) are generated when aqueous GTZ suspension is irradiated with visible light. The generation of (e{sup −}/h+) pair leading to the formation of reactive oxygen species. The ·OH radical and ·O{sub 2}{sup −} can oxidize OTC molecular, resulting in the degradation and mineralization of the organics. - Highlights: • Determine optimal composites of graphene, TiO{sub 2}, and zeolite for maximal photodegradation efficiency via triangular mixture design. • Unravel most promising composites for high stability and absorptive capabilities for photocatalytic degradation. • Disclose time-series profiles of toxicity of advanced oxidation processes (AOPs) treatment of wastewater. • Propose plausible routes of mechanism of photocatalytical degradation of OTC. - Abstract: This first-attempt study revealed mixture design of experiments to obtain the most promising composites of TiO{sub 2} loaded on zeolite and graphene for maximal photocatalytic degradation of oxytetracycline (OTC). The optimal weight ratio of graphene, titanium dioxide (TiO{sub 2}), and zeolite was 1:8:1 determined via experimental design of simplex lattice mixture. The composite material was characterized by XRD, UV–vis, TEM and EDS analysis. The findings showed the composite material had a higher stability and a stronger absorption of the visible light. In addition, it was uniformly dispersed with promising adsorption characteristics. OTC was used as model toxicant to evaluate the photodegradation efficiency of the GTZ (1:8:1). At optimal operating conditions (i.e., pH 7 and 25 °C), complete degradation (ca. 100%) was achieved in 180 min. The biotoxicity of the degraded intermediates of OTC on cell growth of Escherichia coli DH5α were also assayed. After 180 min

  6. Graphene/TiO_2/ZSM-5 composites synthesized by mixture design were used for photocatalytic degradation of oxytetracycline under visible light: Mechanism and biotoxicity

    International Nuclear Information System (INIS)

    Hu, Xin-Yan; Zhou, Kefu; Chen, Bor-Yann; Chang, Chang-Tang

    2016-01-01

    Graphical abstract: The mechanism of OTC degradation can be described as follows. At first, the OTC molecule was adsorbed onto the surface of GTZ material. The conduction band electron (e"−) and valence band holes (h"+) are generated when aqueous GTZ suspension is irradiated with visible light. The generation of (e"−/h+) pair leading to the formation of reactive oxygen species. The ·OH radical and ·O_2"− can oxidize OTC molecular, resulting in the degradation and mineralization of the organics. - Highlights: • Determine optimal composites of graphene, TiO_2, and zeolite for maximal photodegradation efficiency via triangular mixture design. • Unravel most promising composites for high stability and absorptive capabilities for photocatalytic degradation. • Disclose time-series profiles of toxicity of advanced oxidation processes (AOPs) treatment of wastewater. • Propose plausible routes of mechanism of photocatalytical degradation of OTC. - Abstract: This first-attempt study revealed mixture design of experiments to obtain the most promising composites of TiO_2 loaded on zeolite and graphene for maximal photocatalytic degradation of oxytetracycline (OTC). The optimal weight ratio of graphene, titanium dioxide (TiO_2), and zeolite was 1:8:1 determined via experimental design of simplex lattice mixture. The composite material was characterized by XRD, UV–vis, TEM and EDS analysis. The findings showed the composite material had a higher stability and a stronger absorption of the visible light. In addition, it was uniformly dispersed with promising adsorption characteristics. OTC was used as model toxicant to evaluate the photodegradation efficiency of the GTZ (1:8:1). At optimal operating conditions (i.e., pH 7 and 25 °C), complete degradation (ca. 100%) was achieved in 180 min. The biotoxicity of the degraded intermediates of OTC on cell growth of Escherichia coli DH5α were also assayed. After 180 min photocatalytic treatment, OTC solution treated

  7. A dynamic organic Rankine cycle using a zeotropic mixture as the working fluid with composition tuning to match changing ambient conditions

    International Nuclear Information System (INIS)

    Collings, Peter; Yu, Zhibin; Wang, Enhua

    2016-01-01

    Highlights: • A dynamic ORC using a zeotropic mixture with composition tuning is proposed. • The working principle is verified theoretically, based on a thermodynamic model. • Improvements in the resultant power plant’s annual power production are analysed. • The economic benefits have been demonstrated by an economic analysis. - Abstract: Air-cooled condensers are widely used for Organic Rankine Cycle (ORC) power plants where cooling water is unavailable or too costly, but they are then vulnerable to changing ambient air temperatures especially in continental climates, where the air temperature difference between winter and summer can be over 40 °C. A conventional ORC system using a single component working fluid has to be designed according to the maximum air temperature in summer and thus operates far from optimal design conditions for most of the year, leading to low annual average efficiencies. This research proposes a novel dynamic ORC that uses a binary zeotropic mixture as the working fluid, with mechanisms in place to adjust the mixture composition dynamically during operation in response to changing heat sink conditions, significantly improving the overall efficiency of the plant. The working principle of the dynamic ORC concept is analysed. The case study results show that the annual average thermal efficiency can be improved by up to 23% over a conventional ORC when the heat source is 100 °C, while the evaluated increase of the capital cost is less than 7%. The dynamic ORC power plants are particularly attractive for low temperature applications, delivering shorter payback periods compared to conventional ORC systems.

  8. COMPARISON OF THE POPULATIONS OF COMMON WOOD-NYMPH BUTTERFLIES IN BURNED PRAIRIE, UNBURNED PRAIRIE AND OLD FIELD GRASSES

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, M.; Walton, R.

    2007-01-01

    Common wood-nymph butterfl ies are found throughout the United States and Canada. However, not much is known about how they overwinter or their preferences for particular grasses and habitats. In this study, the impact of prairie management plans on the abundance of the wood-nymph population was assessed, as well as the preference of these butterfl ies for areas with native or non-native grasses. The abundance of common wood-nymph butterfl ies was determined using Pollard walks; more common wood-nymph butterfl ies were found in the European grasses than were found in the burned and unburned prairie sites. The majority of the vegetation at each of the three sites was identifi ed and documented. Using a 1 X 3 ANOVA analysis, it was determined there were signifi cantly more butterfl ies in the European grasses than in the burned and unburned prairie sites (p < 0.0005). There was no signifi cant difference between the burned and unburned treatments of the prairie on the common wood-nymph population. A multiple variable linear regression model described the effect of temperature and wind speed on the number of observed common wood-nymph butterfl ies per hour (p = 0.026). These preliminary results need to be supplemented with future studies. Quadrat analysis of the vegetation from all three sites should be done to search for a correlation between common wood-nymph butterfl y abundance per hour and the specifi c types or quantity of vegetation at each site. The effect of vegetation height and density on the observer’s visual fi eld should also be assessed.

  9. Dynamic adsorption of mixtures of Rhodamine B, Pb (II), Cu (II) and Zn(II) ions on composites chitosan-silica-polyethylene glycol membrane

    Science.gov (United States)

    Mahatmanti, F. W.; Rengga, W. D. P.; Kusumastuti, E.; Nuryono

    2018-04-01

    The adsorption of a solution mixture of Rhodamine B, Pb (II), Cu (II) and Zn(II) was studied using dynamic methods employing chitosan-silica-polyethylene glycol (Ch/Si/P) composite membrane as an adsorptive membrane. The composite Ch/Si/P membrane was prepared by mixing a chitosan-based membrane with silica isolated from rice husk ash (ASP) and polyethylene glycol (PEG) as a plasticizer. The resultant composite membrane was a stronger and more flexible membrane than the original chitosan-based membrane as indicated by the maximum percentage of elongation (20.5 %) and minimum Young’s Modulus (80.5 MPa). The composite membrane also showed increased mechanical and hydrophilic properties compared to the chitosan membranes. The membrane was used as adsorption membrane for Pb (II), Cu (II), Cd (II) ions and Rhodamine B dyes in a dynamic system where the permeation and selectivity were determined. The permeation of the components was observed to be in the following order: Rhodamine B > Cd (II) > Pb (II) > Cu (II) whereas the selectivity was shown to decrease the order of Cu (II) > Pb (II) > Cd (II) > Rhodamine B.

  10. Validation of spectroscopic gas analyzer accuracy using gravimetric standard gas mixtures: impact of background gas composition on CO2 quantitation by cavity ring-down spectroscopy

    Science.gov (United States)

    Lim, Jeong Sik; Park, Miyeon; Lee, Jinbok; Lee, Jeongsoon

    2017-12-01

    The effect of background gas composition on the measurement of CO2 levels was investigated by wavelength-scanned cavity ring-down spectrometry (WS-CRDS) employing a spectral line centered at the R(1) of the (3 00 1)III ← (0 0 0) band. For this purpose, eight cylinders with various gas compositions were gravimetrically and volumetrically prepared within 2σ = 0.1 %, and these gas mixtures were introduced into the WS-CRDS analyzer calibrated against standards of ambient air composition. Depending on the gas composition, deviations between CRDS-determined and gravimetrically (or volumetrically) assigned CO2 concentrations ranged from -9.77 to 5.36 µmol mol-1, e.g., excess N2 exhibited a negative deviation, whereas excess Ar showed a positive one. The total pressure broadening coefficients (TPBCs) obtained from the composition of N2, O2, and Ar thoroughly corrected the deviations up to -0.5 to 0.6 µmol mol-1, while these values were -0.43 to 1.43 µmol mol-1 considering PBCs induced by only N2. The use of TPBC enhanced deviations to be corrected to ˜ 0.15 %. Furthermore, the above correction linearly shifted CRDS responses for a large extent of TPBCs ranging from 0.065 to 0.081 cm-1 atm-1. Thus, accurate measurements using optical intensity-based techniques such as WS-CRDS require TPBC-based instrument calibration or use standards prepared in the same background composition of ambient air.

  11. Effects of buffering mineral mixtures on milk yield, milk composition, rumen pH and some blood biochemical parameters in heat stressed dairy cows

    Directory of Open Access Journals (Sweden)

    Adamović Milan

    2014-01-01

    Full Text Available The objective of the work was to investigate the influence of partial substitution of magnesium oxide with natural bentonite in feed mixtures used in feeding of cows during their exposure to heat stress. The investigation lasted 30 days and was carried out during last ten days of may and first twenty days of June when average air temperature in stables was 36.6±2.5oC. In the experiment there were included 30 cows of Holstein breed in first phase of lactation, which were divided into two groups of 15 cows: control (C and experimental (E. Group C was fed with experimental mineral mixture that contained 60% of magnesium oxide during the whole investigation period. Group E was fed with experimental mineral mixture that contained 40% of magnesium oxide as well as 20% of natural bentonite. Remaining ingredients in both control and experimental mineral mixtures were the same and also contained 20% of sodium bicarbonate and 20% of zeolite in the same quantities. The control and experimental mineral mixtures were mixed into complete feed mixture (18% UP in the amount of 1%. At tne end of the investigation period, on the 30th day, there were taken samples of rumens contents for determining pH, and after that blood samples, in which, after the separation of blood serum, were determined glucose concentration, total proteins, albumin, globulin, urea, HDL cholesterol, LDL cholesterol, total bilirubin, calcium and phosphorus, as well as the activity of ALT and AST. By computation there was calculated the ratio between albumin and globulin, ALT and AST, and the ratio between calcium and phosphorus. Daily allowance and milk chemical composition ( percentage of fat, proteins and dry substance were determined at the end of the investigation period, that is on the 30th day of lactation, for each cow individually. Partial substitution of magnesium oxide with bentonite influenced milk production increase, but it was statistically insignificant. Besides that, in E

  12. In vitro cytotoxicity and genotoxicity of composite mixtures of natural rubber and leather residues used for textile applications.

    Science.gov (United States)

    Cavalcante, Dalita Gsm; Gomes, Andressa S; Dos Reis, Elton Ap; Danna, Caroline S; Kerche-Silva, Leandra E; Yoshihara, Eidi; Job, Aldo E

    2017-06-01

    A novel composite material has been developed from natural rubber and leather waste, and a corresponding patent has been filed. This new material may be incorporated into textile and footwear products. However, as leather waste contains chromium, the biocompatibility of this new material and its safety for use in humans must be investigated. The aim of the present study was to investigate the presence of chromium in this new material, determine the amount of each form of chromium present (trivalent or hexavalent), and evaluate the potential cytotoxic and genotoxic effects of the novel composite in two cell lines. The cellular viability was quantified using the MTT3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction method and neutral red uptake assay, and genotoxic damage was analyzed using the comet assay. Our findings indicated that the extracts obtained from the composite were severely cytotoxic to both cell lines tested, and additionally highly genotoxic to MRC-5 cells. These biological responses do not appear to be attributable to the presence of chromium, as the trivalent form was predominantly found to be present in the extracts, indicating that hexavalent chromium is not formed during the production of the novel composite. The incorporation of this new material in applications that do not involve direct contact with the human skin is thus indicated, and it is suggested that the chain of production of this material be studied in order to improve its biocompatibility so that it may safely be used in the textile and footwear industries.

  13. Effect of interfacial composition on uptake of curcumin-piperine mixtures in oil in water emulsions by Caco-2 cells.

    Science.gov (United States)

    Gülseren, İbrahim; Guri, Anilda; Corredig, Milena

    2014-06-01

    Encapsulation in lipid particles is often proposed as a solution to improve curcumin bioavailability. This bioactive molecule has low water solubility and rapidly degrades during digestion. In the present study, the uptake of curcumin from oil in water emulsions, prepared with two different emulsifiers, Tween 20 and Poloxamer 407, was investigated to determine the effect of interfacial composition on absorption. Piperine was added to the curcumin to limit the degradation of curcumin because it is known to inhibit β-glucuronidase activity. The emulsions were administered to Caco-2 cell cultures, which is used as a model for intestinal uptake, and the recovery of curcumin was measured. The curcumin uptake was significantly affected by the type of interface, and the extent of curcumin uptake improved significantly by piperine addition only in the case of oil-in-water emulsions stabilized by Poloxamer 407. This work provides further evidence of the importance of interfacial composition on the delivery of bioactives.

  14. Effects of solvent concentration and composition on protein dynamics: 13C MAS NMR studies of elastin in glycerol-water mixtures.

    Science.gov (United States)

    Demuth, Dominik; Haase, Nils; Malzacher, Daniel; Vogel, Michael

    2015-08-01

    We use (13)C CP MAS NMR to investigate the dependence of elastin dynamics on the concentration and composition of the solvent at various temperatures. For elastin in pure glycerol, line-shape analysis shows that larger-scale fluctuations of the protein backbone require a minimum glycerol concentration of ~0.6 g/g at ambient temperature, while smaller-scale fluctuations are activated at lower solvation levels of ~0.2 g/g. Immersing elastin in various glycerol-water mixtures, we observe at room temperature that the protein mobility is higher for lower glycerol fractions in the solvent and, thus, lower solvent viscosity. When decreasing the temperature, the elastin spectra approach the line shape for the rigid protein at 245 K for all studied samples, indicating that the protein ceases to be mobile on the experimental time scale of ~10(-5) s. Our findings yield evidence for a strong coupling between elastin fluctuations and solvent dynamics and, hence, such interaction is not restricted to the case of protein-water mixtures. Spectral resolution of different carbon species reveals that the protein-solvent couplings can, however, be different for side chain and backbone units. We discuss these results against the background of the slaving model for protein dynamics. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Simultaneous influence of gas mixture composition and process temperature on Fe2O3->FeO reduction kinetics: neural network modeling

    Directory of Open Access Journals (Sweden)

    K. Piotrowski

    2005-09-01

    Full Text Available The kinetics of Fe2O3->FeO reaction was investigated. The thermogravimetric (TGA data covered the reduction of hematite both by pure species (nitrogen diluted CO or H2 and by their mixture. The conventional analysis has indicated that initially the reduction of hematite is a complex, surface controlled process, however once a thin layer of lower oxidation state iron oxides (magnetite, wüstite is formed on the surface, it changes to diffusion control. Artificial Neural Network (ANN has proved to be a convenient tool for modeling of this complex, heterogeneous reaction runs within the both (kinetic and diffusion regions, correctly considering influence of temperature and gas composition effects and their complex interactions. ANN's model shows the capability to mimic some extreme (minimum of the reaction rate within the determined temperature window, while the Arrhenius dependency is of limited use.

  16. Direct numerical simulations of ignition of a lean n-heptane/air mixture with temperature and composition inhomogeneities relevant to HCCI and SCCI combustion

    KAUST Repository

    Luong, Minh Bau

    2015-12-01

    The effects of temperature and composition stratifications on the ignition of a lean n-heptane/air mixture at three initial mean temperatures under elevated pressure are investigated using direct numerical simulations (DNSs) with a 58-species reduced mechanism. Two-dimensional DNSs are performed by varying several key parameters: initial mean temperature, T0, and the variance of temperature and equivalence ratio (T\\' and φ\\') with different T-φcorrelations. It is found that for cases with φ\\' only, the overall combustion occurs more quickly and the mean heat release rate (HRR) increases more slowly with increasing φ\\' regardless of T0. For cases with T\\' only, however, the overall combustion is retarded/advanced in time with increasing T\\' for low/high T0 relative to the negative-temperature coefficient (NTC) regime resulting from a longer/shorter overall ignition delay of the mixture. For cases with uncorrelated T-φfields, the mean HRR is more distributed over time compared to the corresponding cases with T\\' or φ\\' only. For negatively-correlated cases, however, the temporal evolution of the overall combustion exhibits quite non-monotonic behavior with increasing T\\' and φ\\' depending on T0. All of these characteristics are found to be primarily related to the 0-D ignition delays of initial mixtures, the relative timescales between 0-D ignition delay and turbulence, and the dominance of the deflagration mode during the ignition. These results suggest that an appropriate combination of T\\' and φ\\' together with a well-prepared T-φdistribution can alleviate an excessive pressure-rise rate (PRR) and control ignition-timing in homogeneous charge compression-ignition (HCCI) combustion. In addition, critical species and reactions for the ignition of n-heptane/air mixture through the whole ignition process are estimated by comparing the temporal evolution of the mean mass fractions of important species with the overall reaction pathways of n

  17. Synthesis of a TiBw/Ti6Al4V composite by powder compact extrusion using a blended powder mixture

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Huiyang, E-mail: hl209@waikato.ac.nz [Waikato Center for Advanced Materials, School of Engineering, University of Waikato, Hamilton (New Zealand); Zhang, Deliang, E-mail: zhangdeliang@sjtu.edu.cn [State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai (China); Gabbitas, Brian, E-mail: briang@waikato.ac.nz [Waikato Center for Advanced Materials, School of Engineering, University of Waikato, Hamilton (New Zealand); Yang, Fei, E-mail: fyang@waikato.ac.nz [Waikato Center for Advanced Materials, School of Engineering, University of Waikato, Hamilton (New Zealand); Matthews, Steven, E-mail: S.Matthews@massey.ac.nz [School of Engineering and Advanced Technology, Massey University, Auckland (New Zealand)

    2014-09-01

    Highlights: • TiB/Ti6Al4V composites were prepared from extruded BE powders. • Different starting powders affected the morphologies of TiB whiskers formed in-situ. • A TiB/Ti6Al4V composite with TiB whiskers had good strength and ductility. • The strength and ductility achieved were superior to those obtained by other methods. - Abstract: A Ti–6 wt%Al–4 wt%V alloy (Ti6Al4V) matrix composite, reinforced by in situ synthesized TiB whiskers (TiBw) has been successfully fabricated by powder compact extrusion using a blended powder mixture. The microstructural characterization of the various extruded samples showed that the different starting powders, pre-alloyed powder plus boron powder or titanium plus Al–40V master alloy powder plus boron powder, had a significant effect on the morphology of the in situ synthesized TiB whiskers. It is also evident that the TiB whiskers affect the microstructural evolution of the Ti6Al4V matrix. The tensile test results indicated that the composite with a dispersion of fine TiB whiskers with high aspect ratios exhibited a high ultimate tensile stress (UTS) and yield stress (YS) of 1436 MPa and 1361 MPa, respectively, a reasonably good tensile ductility reflected by an elongation to fracture of 5.6% was also achieved. This is a significant improvement compared with as-extruded monolithic Ti6Al4V alloy produced in this study.

  18. Synthesis of a TiBw/Ti6Al4V composite by powder compact extrusion using a blended powder mixture

    International Nuclear Information System (INIS)

    Lu, Huiyang; Zhang, Deliang; Gabbitas, Brian; Yang, Fei; Matthews, Steven

    2014-01-01

    Highlights: • TiB/Ti6Al4V composites were prepared from extruded BE powders. • Different starting powders affected the morphologies of TiB whiskers formed in-situ. • A TiB/Ti6Al4V composite with TiB whiskers had good strength and ductility. • The strength and ductility achieved were superior to those obtained by other methods. - Abstract: A Ti–6 wt%Al–4 wt%V alloy (Ti6Al4V) matrix composite, reinforced by in situ synthesized TiB whiskers (TiBw) has been successfully fabricated by powder compact extrusion using a blended powder mixture. The microstructural characterization of the various extruded samples showed that the different starting powders, pre-alloyed powder plus boron powder or titanium plus Al–40V master alloy powder plus boron powder, had a significant effect on the morphology of the in situ synthesized TiB whiskers. It is also evident that the TiB whiskers affect the microstructural evolution of the Ti6Al4V matrix. The tensile test results indicated that the composite with a dispersion of fine TiB whiskers with high aspect ratios exhibited a high ultimate tensile stress (UTS) and yield stress (YS) of 1436 MPa and 1361 MPa, respectively, a reasonably good tensile ductility reflected by an elongation to fracture of 5.6% was also achieved. This is a significant improvement compared with as-extruded monolithic Ti6Al4V alloy produced in this study

  19. Preparation and properties of palmitic-stearic acid eutectic mixture/expanded graphite composite as phase change material for energy storage

    International Nuclear Information System (INIS)

    Zhang, Nan; Yuan, Yanping; Du, Yanxia; Cao, Xiaoling; Yuan, Yaguang

    2014-01-01

    A novel composite PCM (phase change material) with PA-SA (palmitic-stearic acid) eutectic mixture as PCM and EG (expanded graphite) as supporting material was prepared. The optimum absorption ratio of PA-SA/EG (Palmitic-stearic acid/expanded graphite) composite PCM was determined as PA-SA:EG = 13:1 (by mass). Scanning electron microscope and Fourier transformation infrared spectroscopy results show that PA-SA was uniformly distributed in the porous network structure of EG due to the physical action. Thermal property and thermal stability of the PA-SA/EG composite PCM were characterized by DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis). DSC results indicated that the melting and freezing temperatures and latent heats of PA-SA/EG were measured as 53.89 °C and 54.37 °C, and 166.27 J/g and 166.13 J/g. TGA test results revealed that PA-SA/EG had a good thermal stability in working temperature range. Thermal cycling test results showed PA-SA/EG had a good thermal reliability after 720 thermal cycles. Thermal conductivity of the composite PCM was measured as 2.51 W/m K, much higher than that of PA-SA. The thermal energy storage and release rates of PA-SA/EG were also increased due to the high thermal conductivity of EG. In conclusion, the prepared PA-SA/EG composite PCM can be acted as a potential material for thermal energy storage due to the acceptable thermal properties, good thermal reliability and stability, high thermal conductivity. - Highlights: • PA-SA/EG (Palmitic-stearic acid/expanded graphite) composite PCM was prepared. • Optimum absorption ratio of PA-SA in EG was obtained as 13:1 (by mass). • Thermal conductivity and performance of PA-SA/EG have been significate improved. • PA-SA/EG has a good thermal reliability and thermal stability

  20. Dependence of the mechanical fracture energy of the polymeric composite material from the mixture of filler fractions

    Directory of Open Access Journals (Sweden)

    E. M. Nurullaev

    2015-01-01

    Full Text Available This paper for the first time presents an equation for calculating the mechanical fracture energy of the polymeric composite material (PCM with regard to the basic formulation parameters. By means of the developed computer program the authors calculated the mechanical fracture energy of the polymer binder of the 3D cross-linked plasticized elastomer filled with multifractional silica. The solution of the integral equation was implemented using the corresponding dependence of stress on relative elongation at uniaxial tension. Engineering application of the theory was considered with respect to asphalt road covering. The authors proposed a generalized dependence of ruptural deformation of the polymer binder from the effective concentration of chemical and physical (intermolecular bonds for calculating the mechanical fracture energy of available and advanced PCMs as filled elastomers.

  1. Study of Influence of Composite Materials Components on Properties of Concrete Mixtures and Concrete in Time Dynamics

    Science.gov (United States)

    Butakova, M. D.; Gorbunov, S. P.

    2017-11-01

    It is accepted to call concrete a special construction mix which consists of several main components - most often, these are cement, water and various fillers. As a result of grout hardening, the artificial stone, used in many areas where durability, stability and durability are required, is formed. To improve the main characteristics of concrete, various additives are added to the mix. These substances are also capable of accelerating the speed of construction and reducing the funds expenditure. It is especially important to apply additives at the installation of coverings to airfields, at the construction of moorings, roads, at the laying of pools or during other hydraulic engineering constructions, and also at the construction of monolithic industrial facilities and houses. The article deals with the composition and quantity of complex organomineral additives, the duration and conditions for the formation of composites’ structure.

  2. Effect of diet composition and mixture of selected food additives on the erythrocytic system and iron metabolism in peripheral blood of male rats.

    Science.gov (United States)

    Sadowska, Joanna; Kuchlewska, Magdalena

    2011-01-01

    Metabolic processes of food additives which are "exogenous xenobiotics" are catalysed, primarily, by enzymes located in microsomes of hepatocytes affiliated to P-450 cytochrome superfamily, containing iron. The aim of the study was to investigate the effect of diet composition and selected food additives on the erythrocyte system and iron metabolism in peripheral blood of male rats. The experiment was carried out on 30 male rats sorted into three equinumerous groups. For drinking animals received pure, settled tap water, animals from group III were receiving additionally an aqueous solution of sodium (nitrate), potassium nitrite, benzoic acid, sorbic acid and monosodium glutamate. Ascertained a significant effect of changes in diet composition on the increase in hematocrit marker value and the count of red blood cells in blood of animals examined. Used food additives diminished hemoglobin concentration, hematocrit value and red blood cell count, diminishing also iron concentration in serum, the total iron binding capacity and transferrin saturation with iron. Analysis of the results allowed ascertain adverse changes in values of the erythrocytic system markers, occurring under the influence of the applied mixture of food additives. Used food additives change the iron metabolism, most likely from the necessity of applied xenobiotics biotransformation by heme-containing monoxygenases of P-450 cytochrome.

  3. Application of dry separative methods for decreasing content the residues unburned coal and separation Fe from black coal flies ash

    Directory of Open Access Journals (Sweden)

    František Kaľavský

    2008-06-01

    Full Text Available Main obstacle using of fly ashes in building, that is its main consumer, is the residue of unburned coal; it is expressed of loss onignition - LOI. In present, the valid STN and EU standard limits the content of LOI to 3 – 5 %, in national conditions maximum 7 %.Application of processing technologies also has to assure utilization of fly ash that provides a possibility of complex utilizationof individual products obtained by modification.By means of corona separation, based on different conductivity of individual fly ash elements, it is possible to separate unburnedcoal particles. The fly ash sample from black coal burning in melting boiler that was deposited on fly ash deposit, content of LOIof dielectric particle 6,45 % at 61 % weight yield was achieved. In the samples taken from dry taking of fly ash the non-conductingproduct contained 7,72 % of LOI at 73 % of weight yield.

  4. Consequences of unburned hydrocarbons on microstreamer dynamics and chemistry during plasma remediation of NO sub x using dielectric barrier discharges

    CERN Document Server

    Dorai, R

    2003-01-01

    Atmospheric pressure plasmas, and dielectric barrier discharges (DBDs) in particular, are being investigated for their use in the remediation of nitrogen oxides (NO sub x) from automotive exhausts. In their normal mode of operation, DBDs consist of a large density of short-lived filamentary microdischarges. Localized energy deposition results in spatially nonuniform gas temperatures and species densities which initiate advective and diffusive transport. Diesel exhausts, one of the major sources of NO sub x , typically contain unburned hydrocarbons (UHCs) which significantly influence the NO sub x chemistry during plasma remediation. In this paper, we discuss results from a computational investigation of the consequences of UHC chemistry on radial transport dynamics and remediation of NO sub x. In the presence of UHCs, radicals such as O and OH are dominantly consumed in the microstreamer region and their transport to larger radii is reduced. As a result, the conversion of NO to NO sub 2 is mainly restricted t...

  5. Adsorption of Naphthol Green B on unburned carbon: 2- and 3- parameter linear and non-linear equilibrium modelling

    Czech Academy of Sciences Publication Activity Database

    Bartoňová, L.; Ruppenthalová, Lucie; Ritz, M.

    2017-01-01

    Roč. 25, č. 1 (2017), s. 37-44 ISSN 1004-9541 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : adsorption * unburned carbon * Naphthol Green B * isotherms * Redlich–Peterson model Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 1.174, year: 2016 http://ac.els-cdn.com/S100495411630218X/1-s2.0-S100495411630218X-main.pdf?_tid=cac3f0e4-9a87-11e6-a1c5-00000aacb360&acdnat=1477382049_e99a7a8e381310d60cafbb816571cdd5

  6. Factors affecting the abundance of leaf-litter arthropods in unburned and thrice-burned seasonally-dry Amazonian forests.

    Science.gov (United States)

    Silveira, Juliana M; Barlow, Jos; Louzada, Julio; Moutinho, Paulo

    2010-09-21

    Fire is frequently used as a land management tool for cattle ranching and annual crops in the Amazon. However, these maintenance fires often escape into surrounding forests, with potentially severe impacts for forest biodiversity. We examined the effect of experimental fires on leaf-litter arthropod abundance in a seasonally-dry forest in the Brazilian Amazon. The study plots (50 ha each) included a thrice-burned forest and an unburned control forest. Pitfall-trap samples were collected at 160 randomly selected points in both plots, with sampling stratified across four intra-annual replicates across the dry and wet seasons, corresponding to 6, 8, 10 and 12 months after the most recent fire. Arthropods were identified to the level of order (separating Formicidae). In order to better understand the processes that determine arthropod abundance in thrice-burned forests, we measured canopy openness, understory density and litter depth. All arthropod taxa were significantly affected by fire and season. In addition, the interactions between burn treatment and season were highly significant for all taxa but Isoptera. The burned plot was characterized by a more open canopy, lower understory density and shallower litter depth. Hierarchical partitioning revealed that canopy openness was the most important factor explaining arthropod order abundances in the thrice-burned plot, whereas all three environmental variables were significant in the unburned control plot. These results reveal the marked impact of recurrent wildfires and seasonality on litter arthropods in this transitional forest, and demonstrate the overwhelming importance of canopy-openness in driving post-fire arthropod abundance.

  7. Performance of Carbon Nanotube/Polysulfone (CNT/Psf Composite Membranes during Oil–Water Mixture Separation: Effect of CNT Dispersion Method

    Directory of Open Access Journals (Sweden)

    Michael Olawale Daramola

    2017-03-01

    Full Text Available Effect of the dispersion method employed during the synthesis of carbon nanotube (CNT/polysulfone-infused composite membranes on the quality and separation performance of the membranes during oil–water mixture separation is demonstrated. Carbon nanotube/polysulfone composite membranes containing 5% CNT and pure polysulfone membrane (with 0% CNT were synthesized using phase inversion. Three CNT dispersion methods referred to as Method 1 (M1, Method 2 (M2, and Method 3 (M3 were used to disperse the CNTs. Morphology and surface property of the synthesized membranes were checked with scanning electron microscopy (SEM and Fourier-transform infrared (FTIR spectroscopy, respectively. Separation performance of the membranes was evaluated by applying the membrane to the separation of oil–water emulsion using a cross-flow filtration setup. The functional groups obtained from the FTIR spectra for the membranes and the CNTs included carboxylic acid groups (O–H and carbonyl group (C=O which are responsible for the hydrophilic properties of the membranes. The contact angles for the membranes obtained from Method 1, Method 2, and Method 3 were 76.6° ± 5.0°, 77.9° ± 1.3°, and 77.3° ± 4.5°, respectively, and 88.1° ± 2.1° was obtained for the pure polysulfone membrane. The oil rejection (OR for the synthesized composite membranes from Method 1, Method 2, and Method 3 were 48.71%, 65.86%, and 99.88%, respectively, indicating that Method 3 resulted in membrane of the best quality and separation performance.

  8. Experimental design for a basic mixture on a fluorinated packing. The effect of composition of the mobile phase.

    Science.gov (United States)

    Wang, Y; Harrison, M; Clark, B J

    2006-02-10

    An optimization methodology is introduced for investigating the separation and the retention behavior of analytes on a new fluorinated reversed-phase packing. Ten basic compounds were selected as test probes to study the predictive models developed by using SPSS and MATLAB software. A two-level orthogonal array design (OAD) was used to extract significant parameters. The significant factors were optimised using a central composite design to obtain the quadratic relationship between the dependent and the independent variables. Using this strategy, response surfaces were derived as the 3D and contour plots, and mathematical models were defined for the separation. The models had a satisfactory coefficient (R(2) > 0.97, n = 16). For the test compounds, the best separation condition was: MeCN/30 mM phosphate buffer pH 7.1(55.5:44.5, v/v) and 10 basic solutes were resolved in 22 min. The significant influence of the concentration of buffer shows that different mechanisms of separation for basic compounds on the fluorinated packing exist compared with a common ODS stationary phase.

  9. Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition, chlorine content and temperature.

    Science.gov (United States)

    Saqib, Naeem; Bäckström, Mattias

    2014-12-01

    Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of fly ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature. Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine content have significant effects on partitioning characteristics by increasing the formation and vaporization of highly volatile metal chlorides. Zinc and cadmium concentrations in fly ash increase with the incineration temperature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Mixtures and interactions

    NARCIS (Netherlands)

    Groten, J.P.

    2000-01-01

    Drinking water can be considered as a complex mixture that consists of tens, hundreds or thousands of chemicals of which the composition is qualitatively and quantitatively not fully known. From a public health point of view it is most relevant to answer the question of whether chemicals in drinking

  11. Trace element partitioning in ashes from boilers firing pure wood or mixtures of solid waste with respect to fuel composition, chlorine content and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Saqib, Naeem, E-mail: naeem.saqib@oru.se; Bäckström, Mattias, E-mail: mattias.backstrom@oru.se

    2014-12-15

    Highlights: • Different solids waste incineration is discussed in grate fired and fluidized bed boilers. • We explained waste composition, temperature and chlorine effects on metal partitioning. • Excessive chlorine content can change oxide to chloride equilibrium partitioning the trace elements in fly ash. • Volatility increases with temperature due to increase in vapor pressure of metals and compounds. • In Fluidized bed boiler, most metals find themselves in fly ash, especially for wood incineration. - Abstract: Trace element partitioning in solid waste (household waste, industrial waste, waste wood chips and waste mixtures) incineration residues was investigated. Samples of fly ash and bottom ash were collected from six incineration facilities across Sweden including two grate fired and four fluidized bed incinerators, to have a variation in the input fuel composition (from pure biofuel to mixture of waste) and different temperature boiler conditions. As trace element concentrations in the input waste at the same facilities have already been analyzed, the present study focuses on the concentration of trace elements in the waste fuel, their distribution in the incineration residues with respect to chlorine content of waste and combustion temperature. Results indicate that Zn, Cu and Pb are dominating trace elements in the waste fuel. Highly volatile elements mercury and cadmium are mainly found in fly ash in all cases; 2/3 of lead also end up in fly ash while Zn, As and Sb show a large variation in distribution with most of them residing in the fly ash. Lithophilic elements such as copper and chromium are mainly found in bottom ash from grate fired facilities while partition mostly into fly ash from fluidized bed incinerators, especially for plants fuelled by waste wood or ordinary wood chips. There is no specific correlation between input concentration of an element in the waste fuel and fraction partitioned to fly ash. Temperature and chlorine

  12. High-resolution transmission electron microscopy studies of graphite materials prepared by high-temperature treatment of unburned carbon concentrates from combustion fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Miguel Cabielles; Jean-Nol Rouzaud; Ana B. Garcia [Instituto Nacional del Carbn (INCAR), Oviedo (Spain)

    2009-01-15

    High-resolution transmission electron microscopy (HRTEM) has been used in this work to study the microstructural (structure and microtexture) changes occurring during the high-temperature treatment of the unburned carbon concentrates from coal combustion fly ashes. Emphasis was placed on two aspects: (i) the development of graphitic carbon structures and (ii) the disordered carbon forms remaining in the graphitized samples. In addition, by coupling HRTEM with energy-dispersive spectroscopy, the transformations with the temperature of the inorganic matter (mainly iron- and silicon-based phases) of the unburned carbon concentrates were evidenced. The HRTEM results were compared to the averaged structural order of the materials as evaluated by X-ray diffraction (XRD) and Raman spectroscopy. As indicated by XRD and Raman parameters, more-ordered materials were obtained from the unburned carbon concentrates with higher mineral/inorganic matter, thus inferring the catalytic effect of some of their components. However, the average character of the information provided by these instrumental techniques seems to be inconclusive in discriminating between carbon structures with different degrees of order (stricto sensu graphite, graphitic, turbostratic, etc.) in a given graphitized unburned carbon. Unlike XRD and Raman, HRTEM is a useful tool for imaging directly the profile of the polyaromatic layers (graphene planes), thus allowing the sample heterogeneity to be looked at, specifically the presence of disordered carbon phases. 49 refs., 9 figs., 3 tabs.

  13. Grouting mixture

    Energy Technology Data Exchange (ETDEWEB)

    Klyusov, A A; Bakshutov, V S; Kulyavtsev, V A

    1980-10-23

    A grouting mixture is proposed for low-temperature boreholes. The mixture contains cement, beta gypsum polyhydrate, and calcium chloride, so as to increase the water resistance and strength properties of expanding brick at conditions from 20 to -5/sup 0/ C, the components are in the following ratios: (by wt.-%): cement, 77.45-88.06; beta gypsum polyhydrate, 9.79-19.36; calcium chloride, 2.15-3.19. Grouting mortar for cold boreholes serves as the cement.

  14. Wetting-layer formation mechanisms of surface-directed phase separation under different quench depths with off-critical compositions in polymer binary mixture

    Science.gov (United States)

    Yan, Li-Tang; Xie, Xu-Ming

    2007-02-01

    Focusing on the off-critical condition, the quench depth dependence of surface-directed phase separation in the polymer binary mixture is numerically investigated by combination of the Cahn-Hilliard-Cook theory and the Flory-Huggins-de Gennes theory. Two distinct situations, i.e., for the wetting, the minority component is preferred by the surface and the majority component is preferred by the surface, are discussed in detail. The simulated results show that the formation mechanism of the wetting layer is affected by both the quench depth and the off-critical extent. Moreover, a diagram, illustrating the formation mechanisms of the wetting layer with various quench depths and compositions, is obtained on the basis of the simulated results. It is found that, when the minority component is preferred by the surface, the growth of the wetting layer can exhibit pure diffusion limited growth law, logarithmic growth law, and Lifshitz-Slyozov growth law. However, when the majority component is preferred by the surface, the wetting layer always grows logarithmically, regardless of the quench depth and the off-critical extent. It is interesting that the surface-induced nucleation can be observed in this case. The simulated results demonstrate that the surface-induced nucleation only occurs below a certain value of the quench depth, and a detailed range about it is calculated and indicated. Furthermore, the formation mechanisms of the wetting layer are theoretically analyzed in depth by the chemical potential gradient.

  15. Dependence of enthalpies of dissolution of β-alanyl-β-alanine on the composition of (water + alcohol) mixtures at 298.15 K

    International Nuclear Information System (INIS)

    Smirnov, Valeriy I.; Badelin, Valentin G.

    2011-01-01

    Highlights: · Enthalpies of dissolution of β-alanyl-β-alanine are measured in aqueous methanol, ethanol, 1-propanol and 2-propanol by calorimetry. · Standard values of dissolution and transfer enthalpies of β-alanyl-β-alanine and enthalpy coefficients of pair-wise interactions are calculated. · Dependences of the thermodynamic characteristics of dissolution of β-alanyl-β-alanine on the composition of (water + alcohol) mixtures are determined. - Abstract: The dissolution enthalpies of β-alanyl-β-alanine in aqueous methanol, ethanol, 1-propanol and 2-propanol solutions with an alcohol content up to 0.4 mole fractions have been measured calorimetrically at T = 298.15 K. The standard enthalpies of dissolution, Δ sol H o and transfer, Δ tr H o , of β-alanyl-β-alanine from water into mixed solvents and the enthalpy coefficients of pair-wise interactions, h xy , of β-alanyl-β-alanine with alcohol solvent molecules have been calculated. The results are discussed in terms of solute-solute and solute-solvent interactions.

  16. Investigation by response surface methodology of the combined effect of pH and composition of water-methanol mixtures on the stability of curcuminoids.

    Science.gov (United States)

    D'Archivio, Angelo Antonio; Maggi, Maria Anna

    2017-03-15

    Response surface methodology, coupled to a full factorial three-level experimental design, was applied to investigate the combined influence of pH (between 7.0 and 8.6) and composition of methanol-water mixtures (between 30 and 70% v/v of methanol content) on the stability of curcumin and its analogues demethoxycurcumin and bisdemethoxycurcumin. The response plots revealed that addition of methanol noticeably improved the stability of curcuminoids, this effect being both pH- and structure-dependent. In the central point of the experimental domain, half-life times of curcumin, demethoxycurcumin and bisdemethoxycurcumin were 3.8±0.2, 27±2 and 251±17h, respectively. Stability of curcuminoids increased at lower pH and higher methanol content and decreased in the opposite vertex of the experimental domain. These results can be interpreted by assuming that addition of methanol to water produces a different variation of pH of the medium and apparent pKa values of the ionisable groups of curcuminoids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Hydrogen storage properties of rare earth (RE) borohydrides (RE = La, Er) in composite mixtures with LiBH{sub 4} and LiH

    Energy Technology Data Exchange (ETDEWEB)

    Frommen, Christoph; Heere, Michael [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Riktor, Marit D. [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); SINTEF Materials and Chemistry, Forskningsveien 1, NO-0314 Oslo (Norway); Sørby, Magnus H. [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Hauback, Bjørn C., E-mail: bjorn.hauback@ife.no [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway)

    2015-10-05

    Highlights: • 6LiBH{sub 4}–RECl{sub 3}–3LiH composites (RE = La, Er) studied for the first time. • Drastically reduced decomposition temperature (300 {sup o}C) compared to LiBH{sub 4} (>400 °C). • Partial reversibility for 6LiBH{sub 4}–LaCl{sub 3}–3LiH: (19% at 340 °C, 10 MPa). • Excellent reversibility for 6LiBH{sub 4}–ErCl{sub 3}–3LiH: (80% at 340 °C, 10 MPa). • Reversibility comparable to that obtained for pure LiBH{sub 4} (76% at 600 °C and 15.5 MPa). - Abstract: Mixtures of 6LiBH{sub 4}–RECl{sub 3}–3LiH (RE = La, Er) have been produced by mechanochemical milling and their structure, thermal decomposition and reversibility have been studied. Hydrogen desorption starts around 300 °C in both composites. Heating to 400 °C yields LaB{sub 6}, ErB{sub 4} and REH{sub 2+δ} as major decomposition products. LiBH{sub 4} is destabilized by REH{sub 2+δ} formed through decomposition of the parent borohydrides LiLa(BH{sub 4}){sub 3}Cl and Er(BH{sub 4}){sub 3}, respectively, and its hydrogen release temperature is reduced by 100 °C as compared to pure ball-milled LiBH{sub 4}. The lanthanum-containing composite releases 4.2 wt.% H between 300 and 350 °C and shows a limited reversibility of ∼20% (340 °C, 10 MPa) probably due to hydrogen uptake by some amorphous boron-containing phases. For 6LiBH{sub 4}–ErCl{sub 3}–3LiH about 3 wt.% H is evolved up to 400 °C. Desorption against 0.5 MPa backpressure results in an increased reversibility (∼80%) as compared to vacuum (∼66%). Rehydrogenation (340 °C, 10 MPa) shows the formation of ErH{sub 3} and LiBH{sub 4} at drastically reduced conditions compared to pure LiBH{sub 4} (>400 °C, >10 MPa)

  18. Catalytic reduction of methane/unburned hydrocarbons in smoke from lean-burn gas engines

    International Nuclear Information System (INIS)

    Wit, Jan de.

    1999-01-01

    The aim of this project has been: To describe the flue gas conditions of typical stationary gas engines for cogeneration; To evaluate the predominant causes of deactivation of oxidation catalysts under realistic operation conditions; To develop improved long-term stable oxidation catalysts; To evaluate alternative catalyst-based methane reduction technologies. Most gas engines for stationary purposes are efficient lean-burn gas engines. Both the high efficiency and the very lean operation lead to low exhaust temperatures. However, there is now a tendency to design engines with un-cooled exhaust manifolds. This leads to higher shaft efficiency and increases the exhaust temperature. Exhaust gas composition and temperatures during continuous operation and start/stops are given in this report. Analyses have been made of catalyst samples to find predominant causes for oxidation catalyst deactivation. The analyses have shown that the presence of sulphur dioxide in the flue gas causes sulphur poisoning on the active catalyst surface. This effect is dependent on both the catalyst formulation and the catalyst support material composition. Neither sintering, nor other poisoning components than sulphur have been on the examined catalyst samples. The sulphur dioxide in the exhaust is a result of the sulphur in the odorisation additive used in the natural gas (approx. 10 mg/n 3 m THT) and of the sulphur present in combusted lubrication oil. These sources leads to a level of approx. 0.3 - 0.6 ppm (vol) SO 2 in the exhaust gas. Based on a large number of laboratory tests, a new oxidation catalyst formulation has been developed and successfully tested over 5000 hours of operation at a commercial cogeneration plant. This long-term testing has been additionally supplemented by short-term testings at test sites to see performance under other operation conditions. It has been shown that a rise in flue gas temperature (from e.g. 450 deg. C) will significantly reduce the necessary

  19. A general mixture theory. I. Mixtures of spherical molecules

    Science.gov (United States)

    Hamad, Esam Z.

    1996-08-01

    We present a new general theory for obtaining mixture properties from the pure species equations of state. The theory addresses the composition and the unlike interactions dependence of mixture equation of state. The density expansion of the mixture equation gives the exact composition dependence of all virial coefficients. The theory introduces multiple-index parameters that can be calculated from binary unlike interaction parameters. In this first part of the work, details are presented for the first and second levels of approximations for spherical molecules. The second order model is simple and very accurate. It predicts the compressibility factor of additive hard spheres within simulation uncertainty (equimolar with size ratio of three). For nonadditive hard spheres, comparison with compressibility factor simulation data over a wide range of density, composition, and nonadditivity parameter, gave an average error of 2%. For mixtures of Lennard-Jones molecules, the model predictions are better than the Weeks-Chandler-Anderson perturbation theory.

  20. Separation of unburned carbon from coal fly ash through froth flotation; Sekitanbai no shisshiki datsutanso gijutsu kaihatsu shiken

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, T [Center for Coal Utilization, Japan, Tokyo (Japan); Murakami, T [The Coal Mining Research Center, Japan, Tokyo (Japan)

    1996-09-01

    Coal ash tends to become containing more unburned carbon and porous substances depending on conditions of combustion, whose adverse effects to products due to water adsorbability, absorbability and color tones create obstacles in its utilization. Therefore, research and development works have been progressed on wet type carbon removing technology which is characterized in that coal is pulverized to preferable degrees and subjected to flotation. This paper reports the results obtained during fiscal 1995. The results may be summarized as follows: as a result of the comparison test on a column flotation machine and an FW type flotation machine of machine stirring type, the former machine showed better flotation efficiency; several methods were investigated on crushing as a treatment prior to flotation, whereas a mixer with greater circumferential speed and a homo mixer showed the highest efficiency; strength of the impact to the flotation efficiency was found to decrease in the order of pulp concentration > pretreatment time > collector addition ratio; and as a result of the evaluation on refined ash as a cement admixture and carbons as fuel, possibilities were found in them for practical application. 16 figs., 2 tabs.

  1. Direct numerical simulations of the ignition of a lean biodiesel/air mixture with temperature and composition inhomogeneities at high pressure and intermediate temperature

    KAUST Repository

    Luong, Minhbau

    2014-11-01

    The effects of the stratifications of temperature, T, and equivalence ratio, φ{symbol}, on the ignition characteristics of a lean homogeneous biodiesel/air mixture at high pressure and intermediate temperature are investigated using direct numerical simulations (DNSs). 2-D DNSs are performed at a constant volume with the variance of temperature and equivalence ratio (T′ and φ{symbol}′) together with a 2-D isotropic velocity spectrum superimposed on the initial scalar fields. In addition, three different T s(-) φ{symbol} correlations are investigated: (1) baseline cases with T′ only or φ{symbol}′ only, (2) uncorrelated T s(-) φ{symbol} distribution, and (3) negatively-correlated T s(-) φ{symbol} distribution. It is found that the overall combustion is more advanced and the mean heat release rate is more distributed over time with increasing T′ and/or φ{symbol}′ for the baseline and uncorrelated T s(-) φ{symbol} cases. However, the temporal advancement and distribution of the overall combustion caused by T′ or φ{symbol}′ only are nearly annihilated by the negatively-correlated T s(-) φ{symbol} fields. The chemical explosive mode and Damköhler number analyses verify that for the baseline and uncorrelated T s(-) φ{symbol} cases, the deflagration mode is predominant at the reaction fronts for large T′ and/or φ{symbol}′. On the contrary, the spontaneous ignition mode prevails for cases with small T′ or φ{symbol}′, especially for cases with negative T s(-) φ{symbol} correlations, and hence, simultaneous auto-ignition occurs throughout the entire domain, resulting in an excessive rate of heat release. It is also found that turbulence with large intensity, u′, and a short time scale can effectively smooth out initial thermal and compositional fluctuations such that the overall combustion is induced primarily by spontaneous ignition. Based on the present DNS results, the generalization of the effects of T′, φ{symbol}′, and u

  2. Calculation of the Ionization Coefficient in the Townsend Discharge in the Mixture of Argon and Mercury Vapors with Temperature-Dependent Composition

    Science.gov (United States)

    Bondarenko, G. G.; Dubinina, M. S.; Fisher, M. R.; Kristya, V. I.

    2018-04-01

    For a hybrid model of the low-current discharge considering, along with direct ionization of the mixture components by electrons, the Penning ionization of mercury atoms by metastable argon atoms, the ionization coefficient in the argon-mercury mixture used in illuminating lamps is calculated. The analytical approximation formula describing the dependence of the ionization coefficient of the mixture on the reduced electric field strength and temperature is obtained for sufficiently wide ranges of their variations, and its accuracy is estimated. It is demonstrated that the discharge ignition voltage calculated using this formula is in agreement with the results of simulation and the available experimental data.

  3. Prediction of unburned carbon and NOx in a tangentially fired power station using single coals and blends

    Energy Technology Data Exchange (ETDEWEB)

    R.I. Backreedy; J.M. Jones; L. Ma; M. Pourkashanian; A. Williams; A. Arenillas; B. Arias; J.J. Pis; F. Rubiera [University of Leeds, Leeds (United Kingdom). Energy and Resources Research Institute

    2005-12-01

    Two approaches can be employed for prediction of NOx and unburned carbon. The first approach uses global models such as the 'slice' model which requires the combustor reaction conditions as an input but which has a detailed coal combustion mechanism. The second involves a computational fluid dynamic model that in principle can give detailed information about all aspects of combustion, but usually is restricted in the detail of the combustion model because of the heavy computational demands. The slice model approach can be seen to be complimentary to the CFD approach since the NOx and carbon burnout is computed using the slice model as a post-processor to the CFD model computation. The slice model that has been used previously by our group is applied to a commercial tangentially fired combustor operated in Spain and using a range of Spanish coals and imported coals, some of which are fired as blends. The computed results are compared with experimental measurements, and the accuracy of the approach assessed. The CFD model applied to this case is one of the commercial codes modified to use a number of coal combustion sub-models developed by our group. In particular it can use two independent streams of coal and as such it can be used for the combustion of coal blends. The results show that both model approaches can give good predictions of the NOx and carbon in ash despite the fact that certain parts of the coal combustion models are not exactly the same. However, if a detailed insight into the combustor behaviour is required then the CFD model must be used. 28 refs., 4 figs., 6 tabs.

  4. Composition shift in liquid-recirculation refrigerating systems: an experimental investigation for the pure fluid R134a and the mixture R32/134a

    Energy Technology Data Exchange (ETDEWEB)

    Giuliani, G.; Marchesi Donati, F.; Polonara, F. [Ancona Univ. (Italy). Dip. di Energetica; Hewitt, N.J. [University of Ulster at Coleraine, Northern Ireland (United Kingdom). NICERT

    1999-09-01

    The ability of zeotropic mixtures with a remarkable temperature glide to operate in liquid-recirculation systems is investigated and the results of an experimental comparison between the performances of the pure fluid R134a and the zeotropic mixture R32/134a (25/75% by mass) are presented. R134a performs slightly better in the liquid-recirculation mode than in the traditional dry-expansion mode; on the other hand, liquid-recirculation configuration has a detrimental effect on the zeotropic mixture's performance. The reason for this detrimental effect is the mixture component separation which occurs at the liquid/vapor separator. The effect of this separation is investigated using gas chromatograph analysis.

  5. Characterization of gas sensors for measurement of unburned gases in small district heating furnaces; Karaktaerisering av gassensorer foer maetning av ofoerbraenda aemnen i naervaermecentraler

    Energy Technology Data Exchange (ETDEWEB)

    Eskilsson, David; Roennbaeck, Marie [Swedish National Testing and Research Inst., Boraas (Sweden)

    2004-11-01

    Small district heating boilers are often equipped with a simple O{sub 2}-gauge (lambda sensor) that controls the air supply. There is a great need in small furnaces of continuous measurements of several gas components such as CO, THC and NO{sub x} by simple and cheap technique. Recently, new types of cheap gas sensors have been developed which can be suitable. These gas sensors measure the amount of unburned species (sum of carbon monoxide, hydrocarbons and hydrogen). The objective with this project has been to characterise several gas sensors for unburnt in order to evaluate if they are suitable for combustion control and surveillance of small district heating furnaces. In this work three different gas sensors have been characterised. The sensors were characterised in the laboratory where they were exposed for mixtures of pure gases. The sensors were mounted inside the flue gas channel from a small district heating furnace during 3 months in order to estimate the sensors robustness and the character of the signal in flue gas. The tests with pure gases show that all sensors also reacts for other components besides CO and THC. It is mainly the oxygen concentrations that affect the sensors characteristics but also an altered humidity is important. Measurements in the small district heating furnace showed that none of the sensors was able to measure correctly when mounted directly in the flue gas channel (in situ). The in situ sensors are covered with fly ash and the fly ash also slowly destroys the sensors. Sensors mounted after a filter (exposed for a particle free flue gas) work satisfactory. All of the tested sensors, mounted after a filter, follow the changes in CO concentration well. Some of the sensors are capable of detecting CO as low as 15 ppm. But the accuracy of how well the sensors are able to detect CO varies from sensor to sensor. The measurements also show that even if the sensor is able to follow the changes in CO concentration, the ground signal of

  6. Study of a non-ideal liquid mixture in the hydrodynamic regime. Rayleigh-Brillouin spectra, sound propagation and damping in the CH3CN-CCl4 system at the azeotropic composition

    International Nuclear Information System (INIS)

    Sassi, Paola; D'Elia, Valerio; Cataliotti, Rosario Sergio

    2003-01-01

    The hydrodynamic behaviour in the GHz frequency region has been analzsed for the non-ideal CH 3 CN-CCl 4 liquid mixture around the azeotropic composition. Rayleigh-Brillouin spectra have been measured as a function of temperature and composition, at fixed value of transferred wave vector in the 90 deg. scattering geometry, and also at different scattering angles to study dispersion with frequency of the spectral observables. These measurements have been complemented by those of refractive index, density and viscosity at the same temperatures and mole fraction values. Very interesting behaviour of the classic Brillouin spectral observables, such as the hypersonic propagation speeds and the acoustic absorption coefficients, has been revealed near the azeotropic composition of the mixture at the investigated temperatures, namely 15 deg. C, 25 deg. C, 40 deg. C and 60 deg. C. These effects have been interpreted at the light of the Mountain and Deutch theory of binary solutions and the forecast behaviour of the intermolecular forces around the azeotropic point composition of these very different molecular liquids

  7. Composites

    International Nuclear Information System (INIS)

    Kasen, M.B.

    1983-01-01

    This chapter discusses the roles of composite laminates and aggregates in cryogenic technology. Filamentary-reinforced composites are emphasized because they are the most widely used composite materials. Topics considered include composite systems and terminology, design and fabrication, composite failure, high-pressure reinforced plastic laminates, low-pressure reinforced plastics, reinforced metals, selectively reinforced structures, the effect of cryogenic temperatures, woven-fabric and random-mat composites, uniaxial fiber-reinforced composites, composite joints in cryogenic structures, joining techniques at room temperature, radiation effects, testing laminates at cryogenic temperatures, static and cyclic tensile testing, static and cyclic compression testing, interlaminar shear testing, secondary property tests, and concrete aggregates. It is suggested that cryogenic composite technology would benefit from the development of a fracture mechanics model for predicting the fitness-for-purpose of polymer-matrix composite structures

  8. On a partial differential equation method for determining the free energies and coexisting phase compositions of ternary mixtures from light scattering data.

    Science.gov (United States)

    Ross, David S; Thurston, George M; Lutzer, Carl V

    2008-08-14

    In this paper we present a method for determining the free energies of ternary mixtures from light scattering data. We use an approximation that is appropriate for liquid mixtures, which we formulate as a second-order nonlinear partial differential equation. This partial differential equation (PDE) relates the Hessian of the intensive free energy to the efficiency of light scattering in the forward direction. This basic equation applies in regions of the phase diagram in which the mixtures are thermodynamically stable. In regions in which the mixtures are unstable or metastable, the appropriate PDE is the nonlinear equation for the convex hull. We formulate this equation along with continuity conditions for the transition between the two equations at cloud point loci. We show how to discretize this problem to obtain a finite-difference approximation to it, and we present an iterative method for solving the discretized problem. We present the results of calculations that were done with a computer program that implements our method. These calculations show that our method is capable of reconstructing test free energy functions from simulated light scattering data. If the cloud point loci are known, the method also finds the tie lines and tie triangles that describe thermodynamic equilibrium between two or among three liquid phases. A robust method for solving this PDE problem, such as the one presented here, can be a basis for optical, noninvasive means of characterizing the thermodynamics of multicomponent mixtures.

  9. Device for controlling the composition of the mixture burnt in the combustion spaces of an internal combustion engine. Einrichtung zur Regelung der Zusammensetzung des in den Brennraeumen einer Brennkraftmaschine zur Verbrennung kommenden Betriebsgemisches

    Energy Technology Data Exchange (ETDEWEB)

    Latsch, R; Bianchi, V

    1986-07-31

    The purpose of the invention is to create a device by which the extent of the reaction to the control of the composition of the mixture burnt in the combustion spaces of an internal combustion engine can be measured in a sensitive, responsive and safe way, where the position of the elements detecting the reaction should have a relatively small effect on the accuracy of the measurement and the extent of measurement. According to the invention, this problem is solved by the use of 2 thermal sensors connected to a control device (photo-electric diode, photo-electric transistor), one of which acts catalytically and causes the parts of the gas mixture there to react. The thermal sensor output signals are periodically integrated via the piston work and are entered in the control device. The measured temperature is a measure of how far the method of operation of the internal combustion engine has approached its limits. (HWJ).

  10. Empirical equation of state of the products of the detonation of a liquid explosive based on mixtures of tetranitromethane and nitrobenzene of various compositions

    International Nuclear Information System (INIS)

    Adigamova, T.A.; Davydov, N.B.

    2012-01-01

    The equation of state of the products of the detonation of liquid explosives has been derived by theoretical analysis and calculations. The dependence of the detonation rate on the oxygen balance has been obtained using the existing data on the physicomechanical and detonation properties of liquid explosive mixtures. Calculation dependences of the density on the weight content of nitrobenzene have been obtained [ru

  11. A thoroughly validated spreadsheet for calculating isotopic abundances (H-2, O-17, O-18) for mixtures of waters with different isotopic compositions

    NARCIS (Netherlands)

    Faghihi, V.; Meijer, H. A. J.; Groening, Manfred

    2015-01-01

    RationaleOxygen and hydrogen stable isotopes are widely used tracers for studies on naturally occurring and laboratory mixtures of isotopically different waters. Although the mixing calculations are straightforward to perform, there are ample possibilities to make mistakes, especially when dealing

  12. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2011-01-01

    Strategies are open compositions to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them in full...

  13. Composition

    DEFF Research Database (Denmark)

    2014-01-01

    Memory Pieces are open compositions to be realised solo by an improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound files will in some cases only provide a few minutes' sample. Please DOWNLOAD them to hear them...

  14. Successive composition of two laser channels upon excitation of He-Ar-Xe (2.03 μm) and Ar-Xe (1.73 μm) mixtures by uranium fission fragments

    International Nuclear Information System (INIS)

    Pikulev, A A; Tsvetkov, V M; Sosnin, P V; Sinyanskii, A A

    2009-01-01

    The operation efficiency of the scheme with successive composition of two laser channels upon excitation of the active medium by uranium-235 fission fragments is studied experimentally and numerically. For the He:Ar:Xe = 380:380:1 mixture (at a pressure of 1 atm and the lasing wavelength λ = 2.03 μm) the maximum lasing power of a double channel (1 kW) is almost twice that of a single channel (540 W). Calculations show that in the case of ideal composition (without losses on mirrors) the lasing power of the double channel can be increased to 1.2 kW. For the Ar:Xe = 380:1 mixture (the pressure is 0.5 atm, λ = 1.73 μm) the maximum lasing power of the double channel (620 W) is slightly above that of the single channel (520 W), which is caused by the losses on aluminum mirrors employed for channel doubling and by a negative effect of optical inhomogeneities. In the case of ideal composition, the lasing power can be increased to 830 W. (lasers)

  15. Effects of Processing Parameters on the Fabrication of in-situ Al/TiC Composites by Thermally Activated Combustion Reaction Process in an Aluminium Melt using Al-TiO_2-C Powder Mixtures

    International Nuclear Information System (INIS)

    Kim, Hwa-Jung; Lee, Jung-Moo; Cho, Young-Hee; Kim, Jong-Jin; Kim, Su-Hyeon; Lee, Jae-Chul

    2012-01-01

    A feasible way to fabricate in-situ Al/TiC composites was investigated. An elemental mixture of Al-TiO_2-C pellet was directly added into an Al melt at 800-920°C to form TiC by self-combustion reaction. The addition of CuO initiates the self-combustion reaction to form TiC in 1-2 um at the melt temperature above 850°C. Besides the CuO addition, a diluent element of excess Al plays a significant role in the TiC formation by forming a precursor phase, Al_3Ti. Processing parameters such as CuO content, the amount of excess Al and the melt temperature, have affected the combustion reaction and formation of TiC, and their influences on the microstructures of in-situ Al/TiC composites are examined.

  16. Effects of concentration, temperature and solvent composition on density and apparent molar volume of the binary mixtures of cationic-anionic surfactants in methanol-water mixed solvent media.

    Science.gov (United States)

    Bhattarai, Ajaya; Chatterjee, Sujeet Kumar; Niraula, Tulasi Prasad

    2013-01-01

    The accurate measurements on density of the binary mixtures of cetyltrimethylammonium bromide and sodium dodecyl sulphate in pure water and in methanol(1) + water (2) mixed solvent media containing (0.10, 0.20, and 0.30) volume fractions of methanol at 308.15, 318.15, and 323.15 K are reported. The concentrations are varied from (0.03 to 0.12) mol.l(-1) of sodium dodecyl sulphate in presence of ~ 5.0×10(-4) mol.l(-1) cetyltrimethylammonium bromide. The results showed almost increase in the densities with increasing surfactant mixture concentration, also the densities are found to decrease with increasing temperature over the entire concentration range, investigated in a given mixed solvent medium and these values are found to decrease with increasing methanol content in the solvent composition. The concentration dependence of the apparent molar volumes appear to be negligible over the entire concentration range, investigated in a given mixed solvent medium and the apparent molar volumes increase with increasing temperature and are found to decrease with increasing methanol content in the solvent composition.

  17. Efficient radiative transfer in dust grain mixtures

    OpenAIRE

    Wolf, S.

    2002-01-01

    The influence of a dust grain mixture consisting of spherical dust grains with different radii and/or chemical composition on the resulting temperature structure and spectral energy distribution of a circumstellar shell is investigated. The comparison with the results based on an approximation of dust grain parameters representing the mean optical properties of the corresponding dust grain mixture reveal that (1) the temperature dispersion of a real dust grain mixture decreases substantially ...

  18. Composition

    DEFF Research Database (Denmark)

    Bergstrøm-Nielsen, Carl

    2014-01-01

    Cue Rondo is an open composition to be realised by improvising musicians. See more about my composition practise in the entry "Composition - General Introduction". Caution: streaming the sound/video files will in some cases only provide a few minutes' sample, or the visuals will not appear at all....... Please DOWNLOAD them to see/hear them in full length! This work is licensed under a Creative Commons "by-nc" License. You may for non-commercial purposes use and distribute it, performance instructions as well as specially designated recordings, as long as the author is mentioned. Please see http...

  19. Fibril assembly in whey protein mixtures

    NARCIS (Netherlands)

    Bolder, S.G.

    2007-01-01

    The objective of this thesis was to study fibril assembly in mixtures of whey proteins. The effect of the composition of the protein mixture on the structures and the resulting phase behaviour was investigated. The current work has shown that beta-lactoglobulin is responsible for the fibril assembly

  20. Twisted intra-molecular electron transfer phenomenon of dansyl immobilized on chitosan film and its sensing property to the composition of ethanol-water mixtures

    International Nuclear Information System (INIS)

    Ding Liping; Fang Yu; Jiang Linling; Gao Lining; Yin Xiong

    2005-01-01

    A new fluorescent chitosan film bearing dansyl as a fluorophore has been prepared. The film shows dual fluorescence phenomenon due to twisted intra-molecular charge transfer (TICT) in the excited state of the fluorophore. The position of the maximum emission of the film depends on the polarity of the medium, and it shifts from 460 nm in ethanol to 505 nm in water. The two emissions have been attributed to the emission from the 'locally excited' state or non-charge transfer excited state of dansyl and that from the TICT excited state of the fluorophore, respectively. Existence of TICT phenomenon of the immobilized dansyl has been confirmed and studied by various fluorescence techniques, such as fluorescence lifetime measurement, steady-state and time-resolved fluorescence emission spectroscopy measurements, etc. The ratio, I 505 /I 460 , of the intensities of the two emission bands depends linearly on the concentration of water in ethanol-water mixture provided the concentration is less than 40%. Furthermore, the sensing property of the film to the mixture is reversible

  1. Twisted intra-molecular electron transfer phenomenon of dansyl immobilized on chitosan film and its sensing property to the composition of ethanol-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Ding Liping [School of Chemistry and Materials Science, Shaanxi Normal University, Changan Road No. 199, Xi' an 710062 (China); Fang Yu [School of Chemistry and Materials Science, Shaanxi Normal University, Changan Road No. 199, Xi' an 710062 (China)]. E-mail: yfang@snnu.edu.cn; Jiang Linling [School of Chemistry and Materials Science, Shaanxi Normal University, Changan Road No. 199, Xi' an 710062 (China); Gao Lining [School of Chemistry and Materials Science, Shaanxi Normal University, Changan Road No. 199, Xi' an 710062 (China); Yin Xiong [School of Chemistry and Materials Science, Shaanxi Normal University, Changan Road No. 199, Xi' an 710062 (China)

    2005-05-01

    A new fluorescent chitosan film bearing dansyl as a fluorophore has been prepared. The film shows dual fluorescence phenomenon due to twisted intra-molecular charge transfer (TICT) in the excited state of the fluorophore. The position of the maximum emission of the film depends on the polarity of the medium, and it shifts from 460 nm in ethanol to 505 nm in water. The two emissions have been attributed to the emission from the 'locally excited' state or non-charge transfer excited state of dansyl and that from the TICT excited state of the fluorophore, respectively. Existence of TICT phenomenon of the immobilized dansyl has been confirmed and studied by various fluorescence techniques, such as fluorescence lifetime measurement, steady-state and time-resolved fluorescence emission spectroscopy measurements, etc. The ratio, I {sub 505}/I {sub 460}, of the intensities of the two emission bands depends linearly on the concentration of water in ethanol-water mixture provided the concentration is less than 40%. Furthermore, the sensing property of the film to the mixture is reversible.

  2. Properties of Direct Coal Liquefaction Residue Modified Asphalt Mixture

    Directory of Open Access Journals (Sweden)

    Jie Ji

    2017-01-01

    Full Text Available The objectives of this paper are to use Direct Coal Liquefaction Residue (DLCR to modify the asphalt binders and mixtures and to evaluate the performance of modified asphalt mixtures. The dynamic modulus and phase angle of DCLR and DCLR-composite modified asphalt mixture were analyzed, and the viscoelastic properties of these modified asphalt mixtures were compared to the base asphalt binder SK-90 and Styrene-Butadiene-Styrene (SBS modified asphalt mixtures. The master curves of the asphalt mixtures were shown, and dynamic and viscoelastic behaviors of asphalt mixtures were described using the Christensen-Anderson-Marasteanu (CAM model. The test results show that the dynamic moduli of DCLR and DCLR-composite asphalt mixtures are higher than those of the SK-90 and SBS modified asphalt mixtures. Based on the viscoelastic parameters of CAM models of the asphalt mixtures, the high- and low-temperature performance of DLCR and DCLR-composite modified asphalt mixtures are obviously better than the SK-90 and SBS modified asphalt mixtures. In addition, the DCLR and DCLR-composite modified asphalt mixtures are more insensitive to the frequency compared to SK-90 and SBS modified asphalt mixtures.

  3. Reaction mechanisms and kinetics of processing glucose, xylose and glucose-xylose mixtures under hot compressed water conditions for predicting bio-crude composition

    DEFF Research Database (Denmark)

    Grigoras, Ionela; Toor, Saqib Sohail; Rosendahl, Lasse Aistrup

    Mechanisms for bio-crude formation during the conversion of glucose, xylose and glucose-xylose mixtures as biomass model compounds under hot compressed water conditions are investigated. Studies in literature have shown that the diverse products formed at the early stages of glucose or xylose...... conversion are 5-HMF, erythrose, glyceraldehyde, dihydroxyacetone, pyruvaldehyde, and saccharinic acids resulted through reactions such as dehydration, retro-aldol condensation and isomerization. However, these compounds are mostly water soluble compounds and lack the final steps towards formation of water...... insoluble components at longer reaction times. The effects of pressure, pH, catalyst and reaction time on the main products are examined thoroughly. The possible routes for the formation of oil compounds are developed....

  4. Determination of two-liquid mixture composition by assessing its dielectric parameters 2. modified measuring system for monitoring the dehydration process of bioethanol production

    Directory of Open Access Journals (Sweden)

    Vilitis O.

    2014-02-01

    Full Text Available In Part 2 of the work we describe a modified measuring system for precise monitoring of the dehydration process of bioethanol production. This is based on the earlier proposed system for measuring the concentration of solutions and two-liquid mixtures using devices with capacitive sensors (1-300pF, which provides a stable measuring resolution of ± 0.005 pF at measuring the capacitance of a sensor. In this part of our work we determine additional requirements that are to be imposed on the measuring system at monitoring the ethanol dehydration process and control of bioethanol production. The most important parameters of the developed measuring system are identified. An exemplary calculation is given for the thermocompensated calibration of measuring devices. The results of tests have shown a good performance of the developed measuring system.

  5. Deciding which chemical mixtures risk assessment methods work best for what mixtures

    International Nuclear Information System (INIS)

    Teuschler, Linda K.

    2007-01-01

    The most commonly used chemical mixtures risk assessment methods involve simple notions of additivity and toxicological similarity. Newer methods are emerging in response to the complexities of chemical mixture exposures and effects. Factors based on both science and policy drive decisions regarding whether to conduct a chemical mixtures risk assessment and, if so, which methods to employ. Scientific considerations are based on positive evidence of joint toxic action, elevated human exposure conditions or the potential for significant impacts on human health. Policy issues include legislative drivers that may mandate action even though adequate toxicity data on a specific mixture may not be available and risk assessment goals that impact the choice of risk assessment method to obtain the amount of health protection desired. This paper discusses three important concepts used to choose among available approaches for conducting a chemical mixtures risk assessment: (1) additive joint toxic action of mixture components; (2) toxicological interactions of mixture components; and (3) chemical composition of complex mixtures. It is proposed that scientific support for basic assumptions used in chemical mixtures risk assessment should be developed by expert panels, risk assessment methods experts, and laboratory toxicologists. This is imperative to further develop and refine quantitative methods and provide guidance on their appropriate applications. Risk assessors need scientific support for chemical mixtures risk assessment methods in the form of toxicological data on joint toxic action for high priority mixtures, statistical methods for analyzing dose-response for mixtures, and toxicological and statistical criteria for determining sufficient similarity of complex mixtures

  6. Investigation into isomolar series of Al(NO3)3, Na3VO4 solution mixture and composition of solid phases

    International Nuclear Information System (INIS)

    Chernysh, L.F.; Nakhodnova, A.P.; Makarova, R.A.

    1979-01-01

    Conducted is investigation of properties of isomolar series of aluminium nitrate and sodiUm vanadate solutions at pH of the latter 12.5; 10.0; 7.0 and the temperature of 25 deg C using the methods of pH-metry, conductometry, ''seeming'' volume of precipitations, residual concentration of aluminium and vanadium. It is shown, that the composition property diagram of the system investigated does not reflect the true composition of solid-phase products of the reaction, which depends on the component ratio in solution. Bottom phases of isomolar series are mainly heterogeneous. At the excess of sodium vanadate solution and its high pH values conditions for the basic salt formation are created. At pH of the Na 3 VO 4 solution of 12.5 and 10.0 and Al(NO 3 ) 3 : Na 3 VO 4 ratios 4:6 and 3:7 respectively obtained are the basic aluminium vanadates of the (AlOH) 3 (VO 4 ) 2 x 7.5H 2 O and (AlOH) 2 V 2 O 7 x5H 2 O composition, some of their physicochemical properties being investigated

  7. Investigation into isomolar series of Al(NO/sub 3/)/sub 3/, Na/sub 3/VO/sub 4/ solution mixture and composition of solid phases

    Energy Technology Data Exchange (ETDEWEB)

    Chernysh, L F; Nakhodnova, A P; Makarova, R A [Donetskij Gosudarstvennyj Univ. (Ukrainian SSR)

    1979-11-01

    Conducted is investigation of properties of isomolar series of aluminium nitrate and sodium vanadate solutions at pH of the latter 12.5; 10.0; 7.0 and the temperature of 25 deg C using the methods of pH-metry, conductometry, ''seeming'' volume of precipitations, residual concentration of aluminium and vanadium. It is shown, that the composition property diagram of the system investigated does not reflect the true composition of solid-phase products of the reaction, which depends on the component ratio in solution. Bottom phases of isomolar series are mainly heterogeneous. At the excess of sodium vanadate solution and its high pH values conditions for the basic salt formation are created. At pH of the Na/sub 3/VO/sub 4/ solution of 12.5 and 10.0 and Al(NO/sub 3/)/sub 3/: Na/sub 3/VO/sub 4/ ratios 4:6 and 3:7 respectively obtained are the basic aluminium vanadates of the (AlOH)/sub 3/(VO/sub 4/)/sub 2/x 7.5H/sub 2/O and (AlOH)/sub 2/V/sub 2/O/sub 7/x5H/sub 2/O composition, some of their physicochemical properties being investigated.

  8. Effects of Pleurotus sapidus (Schulzer Sacc. treatment on nutrient composition and ruminal fermentability of barley straw, barley rootless, and a mixture of the two

    Directory of Open Access Journals (Sweden)

    Alfonso Soto-Sánchez

    2015-09-01

    Full Text Available Barley (Hordeum vulgare L., and its derivatives, ranks fourth in cereal production worldwide, and the Pleurotus species are among the most efficient types of lignocellulolytic white-rot fungi. The objective of this research study was to evaluate the degradation of barley straw and barley rootless with an inoculum of Pleurotus to improve their nutritional availability as a food source for ruminants. Two experiments were conducted; the first was to determine the effects of inoculation of Pleurotus sapidus (Schulzer Sacc. (PS in barley straw (BS, barley rootless (BR, and a 75% BS and 25% BR mixture (M. The second experiment was to evaluate the same substrates in vitro ruminal fermentation. Barley rootless had better organic matter (OM degradability than BS after 24 h incubation with PS. The protein content in BR was higher than in BS (P < 0.01. Enzyme activities had the highest concentration from the start of fermentation, and in vitro dry matter (DM degradability in BS and BR increased after 8 and 24 d fermentation, respectively (P < 0.05. Propionic acid concentration was enhanced after 16 d fermentation in BR (P < 0.5. The use of BS combined with BR exhibited better fermentation; this result provides relevant information for integrating BR with other substrates and improving the use of straw, which can be more nutritionally available for feeding ruminants.

  9. SiC/C composite sheets produced from polycarbosilane/resin/bonder mixtures. Polycarbosilane/jushi/bonder kongokei kara sakuseishita SiC/C fukugo sheet

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, K. (The National Defense Academy, Kanagawa (Japan)); Koga, J.; Iwata, T.; Yamanaka, S.; Ono, M. (Mitsubishi Materials Corp., Saitama (Japan))

    1992-02-01

    In a course of work to improve anti-oxidative property and strength of sheets of carbonic composite materials with resins, and further to produce those sheets in an industrial scale, it was tried to prepare two types of 0.4 {approximately} 0.6 m thickness SiC / C composite sheets by heat treatment of two green sheets polycarbosilane ( PCS ) / fran resin / binder type and PCS / (phenol-formaldehyde resin / binder type ) at temperature of 1200 {approximately} 1400{degree}C in an atmosphere of nitrogen. The sheets thus made were subjected to SEM observation, X-ray diffraction, measurement of density and electric resistance, and to tests on weight loss by heating and on bending. The texture of them were as tight as that of their resin carbon ( glassy carbon ). The structural feature is formation of amorphous SiO{sub 2} as a secondary product, This indicates that Si in PCS reacts with oxygen in resin during pyrolysis. The bending strength and anti-oxidative property depend on the SiC content from PCS and that the mixing effect of SiC on them are feasible when a mixing ratio of PCS / resin is higher than (2/1). 13 ref., 7 figs., 2 tabs.

  10. Synthesis, microstructure and mechanical properties of Ti3SiC2-TiC composites pulse discharge sintered from Ti/Si/TiC powder mixture

    International Nuclear Information System (INIS)

    Tian Wubian; Sun Zhengming; Hashimoto, Hitoshi; Du Yulei

    2009-01-01

    Ti 3 SiC 2 -TiC composites with the volume fractions of TiC from 0 to 90% were fabricated by pulse discharge sintering (PDS) technique using Ti-Si-TiC as starting powders in the sintering temperature range of 1250-1400 deg. C. Phase content and microstructure of the synthesized samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The samples sintered at 1400 deg. C are almost fully dense for all compositions with relative density higher than 98%. The phase distribution in the synthesized samples is non-uniform. The Vickers hardness increases almost linearly with the volume fraction of TiC up to a value of 20.1 ± 1.4 GPa at 90 vol.% TiC. The flexural strength increases with the volume fraction of TiC to a maximum value of 655 ± 10 MPa at 50 vol.% TiC. The relationship between microstructure and mechanical properties is discussed.

  11. TEMPERATURE INFLUENCE ON PHASE STABILITY OF ETHANOL-GASOLINE MIXTURES

    Directory of Open Access Journals (Sweden)

    Valerian Cerempei

    2011-06-01

    Full Text Available The article investigates phase stability of ethanol-gasoline mixtures depending on their composition, water concentration in ethanol and ethanol-gasoline mixture and temperature. There have been determined the perfect functioning conditions of spark ignition engines fueled with ethanol-gasoline mixtures.

  12. Optimal mixture experiments

    CERN Document Server

    Sinha, B K; Pal, Manisha; Das, P

    2014-01-01

    The book dwells mainly on the optimality aspects of mixture designs. As mixture models are a special case of regression models, a general discussion on regression designs has been presented, which includes topics like continuous designs, de la Garza phenomenon, Loewner order domination, Equivalence theorems for different optimality criteria and standard optimality results for single variable polynomial regression and multivariate linear and quadratic regression models. This is followed by a review of the available literature on estimation of parameters in mixture models. Based on recent research findings, the volume also introduces optimal mixture designs for estimation of optimum mixing proportions in different mixture models, which include Scheffé’s quadratic model, Darroch-Waller model, log- contrast model, mixture-amount models, random coefficient models and multi-response model.  Robust mixture designs and mixture designs in blocks have been also reviewed. Moreover, some applications of mixture desig...

  13. Solid state reaction synthesis of Ba0.75Sr0.25AlSi2O8 - Al2O3 ceramic composites from mechanically activated precursor mixtures

    Directory of Open Access Journals (Sweden)

    Ramos-Ramírez, M. V.

    2014-06-01

    Full Text Available Ceramic composites with Ba0.75Sr0.25AlSi2O8 (SBAS/Al2O3 mass ratios of: 1 90/10, 2 70/30, and 3 50/50, were in situ synthesized at 900-1500 °C/5 h from mixtures of fly ash, BaCO3, SrCO3 and Al2O3. The green mixtures were mechanically activated for 0, 4 and 8 h in an attrition mill. As a result, the solid state reactions were faster and occurred at lower temperatures. Only the SBAS and Al2O3 phases were obtained at 1300-1500°C, with the SBAS present in composition 1 achieving full conversion from its hexagonal (Hexacelsian into its monoclinic (Celsian form, with or without milling. The higher nominal SBAS content of composition 1 facilitated in it the mentioned conversion, in comparison with the other two studied compositions, which required to be mechanically activated for times that increased with increasing Al2O3 content, in order to attain in them similarly high Hexacelsian to Celsian conversions. The mechanical properties of the synthesized materials increased with increasing milling time, sintering temperature and Al2O3 content. Thus, the best mechanical properties were obtained for composition 3 milled for 8 h and sintered at 1500 °C.Compósitos cerámicos con relaciones Ba0.75Sr0.25AlSi2O8 (SBAS/Al2O3 en masa de: 1 90/10, 2 70/30, y 3 50/50, fueron sintetizados in situ a 900-1500 °C/5 h usando mezclas de cenizas volantes, BaCO3, SrCO3 y Al2O3 . Las mezclas en verde fueron activadas mecánicamente por 0, 4 y 8 h en un molino de atrición. Como resultado, las reacciones en el estado sólido fueron más rápidas y ocurrieron a menores temperaturas. A 1300-1500°C sólo se obtuvo las fases SBAS y Al2O3 , con el SBAS presente en la composición 1 transformado completamente de su forma hexagonal (Hexacelsiana a la monoclínica (Celsiana, con o sin molienda. El mayor contenido nominal de SBAS en esa composición facilitó dicha conversión, en comparación con las otras dos composiciones estudiadas, las cuales requirieron ser activadas mec

  14. Characterization of bioactive mixtures oligogalacturonidos

    International Nuclear Information System (INIS)

    Mederos Torres, Yuliem; Hormaza Montenegro, Josefa; Reynaldo Escobar, Ines; Montesino Sequi, Raquel

    2011-01-01

    Oligogalacturonides are pectic oligosaccharides composed of lineal chains of D-galacturonic acid, linked by α (1-4) glycosidic linkage. Oligogalacturonides' mixtures are obtained by enzymatic hydrolysis of pectins of diverse vegetal species. These oligosaccharides unchain a diverse biological activity in plants, which depends mainly on their polymerization degrees. The National Institute of Agricultural Science has a patent technology at national scale that lets to obtain a mixture of oligogalacturonides with different polymerization degree. In this work is presented the characterization of oligogalacturonides by spectrophotometric analysis attending to their uronic acids, reductor sugars, and neutral sugars content. Also the chromatographic profile of samples in study is obtained, using the derivatization with 2-aminobenzamide label and the separation by high pH anion exchange chromatography. It is achieved the separation of at least eight galacturonic acid oligomers with a variable degree of polymerization. On the other hand, the analysis by Fourier transform-infrared spectroscopy (FT-IR) showed that mixtures were composed by galacturonic acid salts. Results indicated that starting from two pectic acids with different characteristics, mixtures of oligogalacturonides of similar chemical composition could be obtained, but they differ in the proportion that they are presented

  15. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  16. Isotope mixtures of hydrogen in vanadium

    International Nuclear Information System (INIS)

    Mecking-Schloetensack, P.

    1982-03-01

    The properties of isotope-mixtures of Protium and Deuterium stored in Vanadium have been studied. Protium and Deuterium are existing as interstitial-atoms on tetrahedral sites as well as on octahedral sites in this system. This feature leads to large isotopic-effects between the two isotopes. The dependence of the thermodynamic functions like heat of solution, nonconfigurational entropy, specific heat and ordering temperatures from the composition of the isotope-mixture has been determined. (orig.)

  17. Desensitization of metastable intermolecular composites

    Science.gov (United States)

    Busse, James R [South Fork, CO; Dye, Robert C [Los Alamos, NM; Foley, Timothy J [Los Alamos, NM; Higa, Kelvin T [Ridgecrest, CA; Jorgensen, Betty S [Jemez Springs, NM; Sanders, Victor E [White Rock, NM; Son, Steven F [Los Alamos, NM

    2011-04-26

    A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

  18. Perception of trigeminal mixtures.

    Science.gov (United States)

    Filiou, Renée-Pier; Lepore, Franco; Bryant, Bruce; Lundström, Johan N; Frasnelli, Johannes

    2015-01-01

    The trigeminal system is a chemical sense allowing for the perception of chemosensory information in our environment. However, contrary to smell and taste, we lack a thorough understanding of the trigeminal processing of mixtures. We, therefore, investigated trigeminal perception using mixtures of 3 relatively receptor-specific agonists together with one control odor in different proportions to determine basic perceptual dimensions of trigeminal perception. We found that 4 main dimensions were linked to trigeminal perception: sensations of intensity, warmth, coldness, and pain. We subsequently investigated perception of binary mixtures of trigeminal stimuli by means of these 4 perceptual dimensions using different concentrations of a cooling stimulus (eucalyptol) mixed with a stimulus that evokes warmth perception (cinnamaldehyde). To determine if sensory interactions are mainly of central or peripheral origin, we presented stimuli in a physical "mixture" or as a "combination" presented separately to individual nostrils. Results showed that mixtures generally yielded higher ratings than combinations on the trigeminal dimensions "intensity," "warm," and "painful," whereas combinations yielded higher ratings than mixtures on the trigeminal dimension "cold." These results suggest dimension-specific interactions in the perception of trigeminal mixtures, which may be explained by particular interactions that may take place on peripheral or central levels. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Iterative Mixture Component Pruning Algorithm for Gaussian Mixture PHD Filter

    Directory of Open Access Journals (Sweden)

    Xiaoxi Yan

    2014-01-01

    Full Text Available As far as the increasing number of mixture components in the Gaussian mixture PHD filter is concerned, an iterative mixture component pruning algorithm is proposed. The pruning algorithm is based on maximizing the posterior probability density of the mixture weights. The entropy distribution of the mixture weights is adopted as the prior distribution of mixture component parameters. The iterative update formulations of the mixture weights are derived by Lagrange multiplier and Lambert W function. Mixture components, whose weights become negative during iterative procedure, are pruned by setting corresponding mixture weights to zeros. In addition, multiple mixture components with similar parameters describing the same PHD peak can be merged into one mixture component in the algorithm. Simulation results show that the proposed iterative mixture component pruning algorithm is superior to the typical pruning algorithm based on thresholds.

  20. Burning test on a storage drum filled with a mixture of sodiumnitrate and bitumen

    International Nuclear Information System (INIS)

    Knotik, K.; Leichter, P.; Spalek, K.

    1979-01-01

    A burning test on a common storage drum filled with a mixture of sodiumnitrate and bitumen was carried out to show the incinerability of said mixture. A 50 l mild steel drum was filled with 80,7 kg sodiumnitrate/bitumen-mixture. The drum was packed in a 200 l mild steel drum, the remaining space was filled with enough sand to cover the top of the inner drum with 15 cm of sand. The sand packing was then soaked with 70 l of light distillate fuel and ignited. The fuel burned until self-extinguishing occurred. 30 % (22,2 l) of the fuel was burned. 0,7 % of the energy potential was absorbed in the sand layer. The highest measured temperature was 34 0 C at the top of the test drum. It can be concluded, that even under severe external actions the ignition temperature of 400 0 C for bitumen/waste mixtures cannot be reached, providing correct technical storage conditions, which means that the void space in the cavities is filled with unburnable absorbing material like sand or salt. (author)

  1. Ultrasonic study of molecular interaction in binary liquid mixtures at ...

    Indian Academy of Sciences (India)

    The variation of these parameters with composition of the mixture helps us in understanding the nature and extent of interaction between unlike molecules in the mixtures. Further, theoretical values of ultrasonic speed were evaluated using theories and empirical relations. The relative merits of these theories and relations ...

  2. Thermodiffusion in multicomponent n-alkane mixtures.

    Science.gov (United States)

    Galliero, Guillaume; Bataller, Henri; Bazile, Jean-Patrick; Diaz, Joseph; Croccolo, Fabrizio; Hoang, Hai; Vermorel, Romain; Artola, Pierre-Arnaud; Rousseau, Bernard; Vesovic, Velisa; Bou-Ali, M Mounir; Ortiz de Zárate, José M; Xu, Shenghua; Zhang, Ke; Montel, François; Verga, Antonio; Minster, Olivier

    2017-01-01

    Compositional grading within a mixture has a strong impact on the evaluation of the pre-exploitation distribution of hydrocarbons in underground layers and sediments. Thermodiffusion, which leads to a partial diffusive separation of species in a mixture due to the geothermal gradient, is thought to play an important role in determining the distribution of species in a reservoir. However, despite recent progress, thermodiffusion is still difficult to measure and model in multicomponent mixtures. In this work, we report on experimental investigations of the thermodiffusion of multicomponent n -alkane mixtures at pressure above 30 MPa. The experiments have been conducted in space onboard the Shi Jian 10 spacecraft so as to isolate the studied phenomena from convection. For the two exploitable cells, containing a ternary liquid mixture and a condensate gas, measurements have shown that the lightest and heaviest species had a tendency to migrate, relatively to the rest of the species, to the hot and cold region, respectively. These trends have been confirmed by molecular dynamics simulations. The measured condensate gas data have been used to quantify the influence of thermodiffusion on the initial fluid distribution of an idealised one dimension reservoir. The results obtained indicate that thermodiffusion tends to noticeably counteract the influence of gravitational segregation on the vertical distribution of species, which could result in an unstable fluid column. This confirms that, in oil and gas reservoirs, the availability of thermodiffusion data for multicomponent mixtures is crucial for a correct evaluation of the initial state fluid distribution.

  3. Global concentration additivity and prediction of mixture toxicities, taking nitrobenzene derivatives as an example.

    Science.gov (United States)

    Li, Tong; Liu, Shu-Shen; Qu, Rui; Liu, Hai-Ling

    2017-10-01

    The toxicity of a mixture depends not only on the mixture concentration level but also on the mixture ratio. For a multiple-component mixture (MCM) system with a definite chemical composition, the mixture toxicity can be predicted only if the global concentration additivity (GCA) is validated. The so-called GCA means that the toxicity of any mixture in the MCM system is the concentration additive, regardless of what its mixture ratio and concentration level. However, many mixture toxicity reports have usually employed one mixture ratio (such as the EC 50 ratio), the equivalent effect concentration ratio (EECR) design, to specify several mixtures. EECR mixtures cannot simulate the concentration diversity and mixture ratio diversity of mixtures in the real environment, and it is impossible to validate the GCA. Therefore, in this paper, the uniform design ray (UD-Ray) was used to select nine mixture ratios (rays) in the mixture system of five nitrobenzene derivatives (NBDs). The representative UD-Ray mixtures can effectively and rationally describe the diversity in the NBD mixture system. The toxicities of the mixtures to Vibrio qinghaiensis sp.-Q67 were determined by the microplate toxicity analysis (MTA). For each UD-Ray mixture, the concentration addition (CA) model was used to validate whether the mixture toxicity is additive. All of the UD-Ray mixtures of five NBDs are global concentration additive. Afterwards, the CA is employed to predict the toxicities of the external mixtures from three EECR mixture rays with the NOEC, EC 30 , and EC 70 ratios. The predictive toxicities are in good agreement with the experimental toxicities, which testifies to the predictability of the mixture toxicity of the NBDs. Copyright © 2017. Published by Elsevier Inc.

  4. Mixtures Estimation and Applications

    CERN Document Server

    Mengersen, Kerrie; Titterington, Mike

    2011-01-01

    This book uses the EM (expectation maximization) algorithm to simultaneously estimate the missing data and unknown parameter(s) associated with a data set. The parameters describe the component distributions of the mixture; the distributions may be continuous or discrete. The editors provide a complete account of the applications, mathematical structure and statistical analysis of finite mixture distributions along with MCMC computational methods, together with a range of detailed discussions covering the applications of the methods and features chapters from the leading experts on the subject

  5. Detonation velocity in poorly mixed gas mixtures

    Science.gov (United States)

    Prokhorov, E. S.

    2017-10-01

    The technique for computation of the average velocity of plane detonation wave front in poorly mixed mixture of gaseous hydrocarbon fuel and oxygen is proposed. Here it is assumed that along the direction of detonation propagation the chemical composition of the mixture has periodic fluctuations caused, for example, by layered stratification of gas charge. The technique is based on the analysis of functional dependence of ideal (Chapman-Jouget) detonation velocity on mole fraction (with respect to molar concentration) of the fuel. It is shown that the average velocity of detonation can be significantly (by more than 10%) less than the velocity of ideal detonation. The dependence that permits to estimate the degree of mixing of gas mixture basing on the measurements of average detonation velocity is established.

  6. I-optimal mixture designs

    OpenAIRE

    GOOS, Peter; JONES, Bradley; SYAFITRI, Utami

    2013-01-01

    In mixture experiments, the factors under study are proportions of the ingredients of a mixture. The special nature of the factors in a mixture experiment necessitates specific types of regression models, and specific types of experimental designs. Although mixture experiments usually are intended to predict the response(s) for all possible formulations of the mixture and to identify optimal proportions for each of the ingredients, little research has been done concerning their I-optimal desi...

  7. Thermal analysis of pyrotechnic mixture-fireworks, atom-bomb

    International Nuclear Information System (INIS)

    Rajendran, Jeya; Thanulingam, T.L.

    2008-01-01

    Sound level produced from two varieties of sound producing fireworks of atom-bomb, cake bomb and thunder bomb were measured. The pyrotechnic mixture, KNO 3 /S/Al(H 3 BO 3 ) of compositions 57.5/19.9/22.1(0.5)% very much similar to commercial atom-bomb were taken and five cake bomb and seven thunder bomb with different net weight of chemicals were manufactured specifically for analysis. Cake bomb with 1g pyrotechnic mixture and thunder bomb with 2g pyrotechnic mixture produce -3 . Ignition temperature of the mixture is above the melting point of the metallic fuel, Al (660 deg C) and self propagating decomposition occurred at high temperature. The pyrotechnic mixture, KNO 3 /S/Al(H 3 BO 3 ) is a safe mixture from accidental factor, static electricity. DSC studies indicate slight formation of potassium nitrite with evolution of NO above 400 deg C. (author)

  8. Pool Boiling of Hydrocarbon Mixtures on Water

    Energy Technology Data Exchange (ETDEWEB)

    Boee, R.

    1996-09-01

    In maritime transport of liquefied natural gas (LNG) there is a risk of spilling cryogenic liquid onto water. The present doctoral thesis discusses transient boiling experiments in which liquid hydrocarbons were poured onto water and left to boil off. Composition changes during boiling are believed to be connected with the initiation of rapid phase transition in LNG spilled on water. 64 experimental runs were carried out, 14 using pure liquid methane, 36 using methane-ethane, and 14 using methane-propane binary mixtures of different composition. The water surface was open to the atmosphere and covered an area of 200 cm{sup 2} at 25 - 40{sup o}C. The heat flux was obtained by monitoring the change of mass vs time. The void fraction in the boiling layer was measured with a gamma densitometer, and a method for adapting this measurement concept to the case of a boiling cryogenic liquid mixture is suggested. Significant differences in the boil-off characteristics between pure methane and binary mixtures revealed by previous studies are confirmed. Pure methane is in film boiling, whereas the mixtures appear to enter the transitional boiling regime with only small amounts of the second component added. The results indicate that the common assumption that LNG will be in film boiling on water because of the high temperature difference, may be questioned. Comparison with previous work shows that at this small scale the results are influenced by the experimental apparatus and procedures. 66 refs., 76 figs., 28 tabs.

  9. Systems and methods for producing electrical discharges in compositions

    KAUST Repository

    Cha, Min; Zhang, Xuming; Chung, Suk-Ho

    2015-01-01

    Systems and methods configured to produce electrical discharges in compositions, such as those, for example, configured to produce electrical discharges in compositions that comprise mixtures of materials, such as a mixture of a material having a

  10. Computing Properties Of Chemical Mixtures At Equilibrium

    Science.gov (United States)

    Mcbride, B. J.; Gordon, S.

    1995-01-01

    Scientists and engineers need data on chemical equilibrium compositions to calculate theoretical 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 is general program that calculates chemical equilibrium compositions and properties of mixtures for any chemical system for which thermodynamic data are available. Includes thermodynamic data for more than 1,300 gaseous and condensed species and thermal-transport data for 151 gases. Written in FORTRAN 77.

  11. Mixture based outlier filtration

    Czech Academy of Sciences Publication Activity Database

    Pecherková, Pavla; Nagy, Ivan

    2006-01-01

    Roč. 46, č. 2 (2006), s. 30-35 ISSN 1210-2709 R&D Projects: GA MŠk 1M0572; GA MDS 1F43A/003/120 Institutional research plan: CEZ:AV0Z10750506 Keywords : data filtration * system modelling * mixture models Subject RIV: BD - Theory of Information http://library.utia.cas.cz/prace/20060165.pdf

  12. Amorphous metal composites

    International Nuclear Information System (INIS)

    Byrne, M.A.; Lupinski, J.H.

    1984-01-01

    This patent discloses an improved amorphous metal composite and process of making the composite. The amorphous metal composite comprises amorphous metal (e.g. iron) and a low molecular weight thermosetting polymer binder. The process comprises placing an amorphous metal in particulate form and a thermosetting polymer binder powder into a container, mixing these materials, and applying heat and pressure to convert the mixture into an amorphous metal composite

  13. Influence of coprecipitation and mechanical mixture methods on the characteristics of nickel oxide-alumina composites; Influencia dos metodos de coprecipitacao e mistura mecanica nas caracteristicas de compositos oxido de niquel-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, G.L.; Yoshito, W.K.; Ussui, V.; Lima, N.B. de; Lazar, D.R.R., E-mail: gcordeiro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais

    2014-07-01

    Alumina-supported nickel catalysts are currently used in the reforming process due to low cost and high activity for hydrogen production from alcohols. In this work, the effect of preparation methods on nickel oxide-alumina based materials has been investigated. Nickel content was fixed at 15 wt%. Ceramic powders were obtained by coprecipitation in ammonia medium and mechanical mixture. Coprecipitated materials were calcined in air at 750 deg C to obtain the corresponding oxides. Materials obtained by mechanical mixture were prepared by wet milling of nickel oxide and alumina powders, both synthesized by precipitation and calcination in air at 450 and 750 deg C, respectively. Powders were characterized by X-ray diffraction, nitrogen gas sorption by applying the BET method, laser diffraction, scanning electron microscopy, electrophoretic mobility measurements for zeta potential determination and infrared spectroscopy. The results showed that coprecipitation method allowed the production of mixed oxides with high surface area (232,7 ± 3,2 m{sup 2}.g{sup -1}) and normal granulometric distribution while mechanical mixture led to the formation of materials constituted by gamma alumina and nickel oxide phases, with low surface area (136,2 ± 0,5 m{sup 2}.g{sup -1}) and bimodal granulometric distribution. (author)

  14. Mixture for plugging absorption zones

    Energy Technology Data Exchange (ETDEWEB)

    Sitinkov, G V; Kovalenko, N G; Makarov, L V; Zinnatulchin, Ts Kh

    1981-01-17

    A mixture is proposed for plugging absorption zones. The mixture contains synthetic polymer and a solvent. So as to increase the penetrability of the mixture through a reduction in its viscosity and an increase in insulation properties, the compound contains either Capron or Neilon as the synthetic polyamide resin polmyer, and concentrated chloride as the solvent. The mixture is prepared in a special AzINMASh-30 unit (acid cart). After the mixture has been produced, it is injected into the borehole by means of an acid cart pump. So as to prevent coaggulation at the point when the mixture in injected into the stratum through tubes, the mixture is placed betwen chemically inert fluids, for example, a clay mortar. The inert and compressed fluids are injected by means of a cementing unit. The entire process of production and application of the mixture is simple and fully automated through the use of well-known equipment.

  15. Separating Underdetermined Convolutive Speech Mixtures

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Wang, DeLiang; Larsen, Jan

    2006-01-01

    a method for underdetermined blind source separation of convolutive mixtures. The proposed framework is applicable for separation of instantaneous as well as convolutive speech mixtures. It is possible to iteratively extract each speech signal from the mixture by combining blind source separation...

  16. Mixtures of truncated basis functions

    DEFF Research Database (Denmark)

    Langseth, Helge; Nielsen, Thomas Dyhre; Rumí, Rafael

    2012-01-01

    In this paper we propose a framework, called mixtures of truncated basis functions (MoTBFs), for representing general hybrid Bayesian networks. The proposed framework generalizes both the mixture of truncated exponentials (MTEs) framework and the mixture of polynomials (MoPs) framework. Similar t...

  17. Desensitization and recovery of metastable intermolecular composites

    Science.gov (United States)

    Busse, James R [South Fork, CO; Dye, Robert C [Los Alamos, NM; Foley, Timothy J [Los Alamos, NM; Higa, Kelvin T [Ridgecrest, CA; Jorgensen, Betty S [Jemez Springs, NM; Sanders, Victor E [White Rock, NM; Son, Steven F [Los Alamos, NM

    2010-09-07

    A method to substantially desensitize a metastable intermolecular composite material to electrostatic discharge and friction comprising mixing the composite material with an organic diluent and removing enough organic diluent from the mixture to form a mixture with a substantially putty-like consistency, as well as a concomitant method of recovering the metastable intermolecular composite material.

  18. Structural transition of a homopolymer in solvents mixture

    Energy Technology Data Exchange (ETDEWEB)

    Guettari, Moez [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)], E-mail: gtarimoez@yahoo.fr; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)

    2008-07-01

    The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M{sub w} = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X{sub A} is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X{sub A} = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture.

  19. Structural transition of a homopolymer in solvents mixture

    International Nuclear Information System (INIS)

    Guettari, Moez; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh

    2008-01-01

    The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M w = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X A is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X A = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture

  20. Prevalence Incidence Mixture Models

    Science.gov (United States)

    The R package and webtool fits Prevalence Incidence Mixture models to left-censored and irregularly interval-censored time to event data that is commonly found in screening cohorts assembled from electronic health records. Absolute and relative risk can be estimated for simple random sampling, and stratified sampling (the two approaches of superpopulation and a finite population are supported for target populations). Non-parametric (absolute risks only), semi-parametric, weakly-parametric (using B-splines), and some fully parametric (such as the logistic-Weibull) models are supported.

  1. Antiandrogenic activity of phthalate mixtures: Validity of concentration addition

    International Nuclear Information System (INIS)

    Christen, Verena; Crettaz, Pierre; Oberli-Schrämmli, Aurelia; Fent, Karl

    2012-01-01

    Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose–response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC 10 , EC 25 and EC 50 in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approach (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP + DBP, DBP + DEP and DEP + BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC 10 mixtures BBP + DBP, BBP + DEP and DBP + DEP, and the EC 25 mixture of DBP + BPA. A ternary mixture revealed synergism at the EC 50 , and weak antagonistic activity at the EC 25 level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept. -- Highlights: ► Antiandrogenic activity of mixtures of 2 and 3 phthalates are assessed in MDA-kb2 cells. ► Mixture activities followed the concentration addition model. ► A tendency to synergism at high and antagonism at low levels occurred.

  2. Antiandrogenic activity of phthalate mixtures: Validity of concentration addition

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Verena [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Crettaz, Pierre; Oberli-Schrämmli, Aurelia [Swiss Federal Office of Public Health, Division Chemical Products, 3003 Bern (Switzerland); Fent, Karl, E-mail: karl.fent@bluewin.ch [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Swiss Federal Institute of Technology Zürich (ETH Zürich), Department of Environmental Sciences, 8092 Zürich (Switzerland)

    2012-03-01

    Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose–response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC{sub 10}, EC{sub 25} and EC{sub 50} in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approach (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP + DBP, DBP + DEP and DEP + BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC{sub 10} mixtures BBP + DBP, BBP + DEP and DBP + DEP, and the EC{sub 25} mixture of DBP + BPA. A ternary mixture revealed synergism at the EC{sub 50}, and weak antagonistic activity at the EC{sub 25} level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept. -- Highlights: ► Antiandrogenic activity of mixtures of 2 and 3 phthalates are assessed in MDA-kb2 cells. ► Mixture activities followed the concentration addition model. ► A tendency to synergism at high and antagonism at low levels occurred.

  3. Investigation of Asphalt Mixture Creep Behavior Using Thin Beam Specimens

    International Nuclear Information System (INIS)

    Zofka, Adam; Marasteanu, Mihai; Turos, Mugur

    2008-01-01

    The asphalt pavement layer consists of two or more lifts of compacted asphalt mixture; the top of the layer is also exposed to aging, a factor that significantly affects the mixture properties. The current testing specifications use rather thick specimens that cannot be used to investigate the gradual change in properties with pavement depth. This paper investigates the feasibility of using the 3-point bending test with thin asphalt mixture beams (127x12.7x6.35 mm) to determine the low-temperature creep compliance of the mixtures. Several theoretical and semi-empirical models, from the theory of composites, are reviewed and evaluated using numerical and experimental data. Preliminary results show that this method can be used for low-temperature mixture characterization but several crucial factors need further inspection and interpretation

  4. Concrete mixture characterization. Cementitious barriers partnership

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Protiere, Yannick [SIMCO Technologies, Inc., Quebec (Canada)

    2014-12-01

    This report summarizes the characterization study performed on two concrete mixtures used for radioactive waste storage. Both mixtures were prepared with approximately 425 kg of binder. The testing protocol mostly focused on determining the transport properties of the mixtures; volume of permeable voids (porosity), diffusion coefficients, and water permeability were evaluated. Tests were performed after different curing durations. In order to obtain data on the statistical distribution of transport properties, the measurements after 2 years of curing were performed on 10+ samples. Overall, both mixtures exhibited very low tortuosities and permeabilities, a direct consequence of their low water-to-binder ratio and the use of supplementary cementitious materials. The data generated on 2-year old samples showed that porosity, tortuosity and permeability follow a normal distribution. Chloride ponding tests were also performed on test samples. They showed limited chloride ingress, in line with measured transport properties. These test results also showed that both materials react differently with chloride, a consequence of the differences in the binder chemical compositions.

  5. Concrete mixtures with high-workability for ballastless slab tracks

    OpenAIRE

    Olga Smirnova

    2017-01-01

    The concrete track-supporting layer and the monolithic concrete slab of ballastless track systems are made in-situ. For this reason the concrete mixtures of high workability should be used. Influence of the sand kind, the quartz microfiller fineness and quantity as well as quantity of superplasticizer on workability of fresh concrete and durability of hardened concrete is shown. The compositions of the high-workability concrete mixtures with lower consumption of superplasticizer are developed...

  6. Ethane-xenon mixtures under shock conditions

    Science.gov (United States)

    Flicker, Dawn; Magyar, Rudolph; Root, Seth; Cochrane, Kyle; Mattsson, Thomas

    2015-06-01

    Mixtures of light and heavy elements arise in inertial confinement fusion and planetary science. We present results on the physics of molecular scale mixing through a validation study of equation of state (EOS) properties. Density functional theory molecular dynamics (DFT/QMD) at elevated-temperature and pressure is used to obtain the properties of pure xenon, ethane, and various compressed mixture compositions along their principal Hugoniots. To validate the QMD simulations, we performed high-precision shock compression experiments using Sandia's Z-Machine. A bond tracking analysis of the simulations correlates the sharp rise in the Hugoniot curve with completion of dissociation in ethane. DFT-based simulation results compare well with experimental data and are used to provide insight into the dissociation as a function of mixture composition. Interestingly, we find that the compression ratio for complete dissociation is similar for ethane, Xe-ethane, polymethyl-pentene, and polystyrene, suggesting that a limiting compression exists for C-C bonded systems. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, Security Administration under contract DE-AC04-94AL85000.

  7. Thermal signature measurements for ammonium nitrate/fuel mixtures by laser heating

    International Nuclear Information System (INIS)

    Nazarian, Ashot; Presser, Cary

    2016-01-01

    Highlights: • LDTR is a useful diagnostic for characterizing AN/fuel mixture thermochemical behavior. • Each AN/fuel mixture thermal signature was different. • AN/fuel mixture signature features were defined by the individual constituents. • Baseline signatures changed after an experiment. - Abstract: Measurements were carried out to obtain thermal signatures of several ammonium nitrate/fuel (ANF) mixtures, using a laser-heating technique referred to as the laser-driven thermal reactor (LDTR). The mixtures were ammonium nitrate (AN)/kerosene, AN/ethylene glycol, AN/paraffin wax, AN/petroleum jelly, AN/confectioner's sugar, AN/cellulose (tissue paper), nitromethane/cellulose, nitrobenzene/cellulose, AN/cellulose/nitromethane, AN/cellulose/nitrobenzene. These mixtures were also compared with AN/nitromethane and AN/diesel fuel oil, obtained from an earlier investigation. Thermograms for the mixtures, as well as individual constituents, were compared to better understand how sample thermal signature changes with mixture composition. This is the first step in development of a thermal-signature database, to be used along with other signature databases, to improve identification of energetic substances of unknown composition. The results indicated that each individual thermal signature was associated unambiguously with a particular mixture composition. The signature features of a particular mixture were shaped by the individual constituent signatures. It was also uncovered that the baseline signature was modified after an experiment due to coating of unreacted residue on the substrate surface and a change in the reactor sphere oxide layer. Thus, care was required to pre-oxidize the sphere prior to an experiment. A minimum sample mass (which was dependent on composition) was required to detect the signature characteristics. Increased laser power served to magnify signal strength while preserving the signature features. For the mixtures examined, the thermal

  8. Separation of gas mixtures

    International Nuclear Information System (INIS)

    1981-01-01

    Apparatus is described for the separation of a gaseous plasma mixture into components in some of which the original concentration of a specific ion has been greatly increased or decreased, comprising: a source for converting the gaseous mixture into a train of plasma packets; an open-ended vessel with a main section and at least one branch section, adapted to enclose along predetermined tracks the original plasma packets in the main section, and the separated plasma components in the branch sections; drive means for generating travelling magnetic waves along the predetermined tracks with the magnetic flux vector of the waves transverse to each of the tracks; and means for maintaining phase coherence between the plasma packets and the magnetic waves at a value needed for accelerating the components of the packets to different velocities and in such different directions that the plasma of each packet is divided into distinctly separate packets in some of which the original concentration of a specific ion has been greatly increased or decreased, and which plasma packets are collected from the branch sections of the vessels. (author)

  9. Spectrophotometric determination of volautile inorganic hydrides in binary gaseous mixtures

    International Nuclear Information System (INIS)

    Rezchikov, V.G.; Skachkova, I.N.; Kuznetsova, T.S.; Khrushcheva, V.V.

    1985-01-01

    A study was made on possibility of single and continuons analysis of binary mixtures (hydride-gas) for the content of volatile inorganic hydrides (VIH) from absorption spectra in the 185-280 nm band. Dependences of the percentage of VIH transmission on the wavelength are presented. It is shown that the maximum of their absorption depends on the element-hydrogen the bond length and binding energy. Detection limit for boron hydride was established to be n x 10 -3 % vol at 185-190 nm wavelength. Technique for spectrophotometric hydride determination in binary mixtures with hydrogen, argon, helium was developed. The technique provides the continuous control of gaseous mixture composition

  10. Chemical kinetics of detonation in some liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Raikova, Vlada M.; Likholatov, Evgeny A. [Mendeleev University of Chemical Technology, Moscow (Russian Federation)

    2005-09-01

    The main objective of this work is to study the chemical kinetics of detonation reactions in some nitroester mixtures and solutions of nitrocompounds in concentrated nitric acid. The main source of information on chemical kinetics in the detonation wave was the experimental dependence of failure diameter on composition of mixtures. Calculations were carried out in terms of classic theory of Dremin using the SGKR computer code. Effective values for the activation energies and pre-exponential factors for detonation reactions in the mixtures under investigation have been defined. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  11. The influence of wildfire severity on soil char composition and nitrogen dynamics

    Science.gov (United States)

    Rhoades, Charles; Fegel, Timothy; Chow, Alex; Tsai, Kuo-Pei; Norman, John, III; Kelly, Eugene

    2017-04-01

    Forest fires cause lasting ecological changes and alter the biogeochemical processes that control stream water quality. Decreased plant nutrient uptake is the mechanism often held responsible for lasting post-fire shifts in nutrient supply and demand, though other upland and in-stream factors also likely contribute to elevated stream nutrient losses. Soil heating, for example, creates pyrogenic carbon (C) and char layers that influence C and nitrogen (N) cycling. Char layer composition and persistence vary across burned landscapes and are influenced first by fire behavior through the temperature and duration of combustion and then by post-fire erosion. To evaluate the link between soil char and stream C and N export we studied areas burned by the 2002 Hayman Fire, the largest wildfire in Colorado, USA history. We compared soil C and N pools and processes across ecotones that included 1) unburned forests, 2) areas with moderate and 3) high wildfire severity. We analyzed 1-2 cm thick charred organic layers that remain visible 15 years after the fire, underlying mineral soils, and soluble leachate from both layers. Unburned soils released more dissolved organic C and N (DOC and DON) from organic and mineral soil layers than burned soils. The composition of DOC leachate characterized by UV-fluorescence, emission-excitation matrices (EEMs) and Fluorescence Regional Integration (FRI) found similarity between burned and unburned soils, underscoring a common organic matter source. Humic and fulvic acid-like fractions, contained in regions V and III of the FRI model, comprised the majority of the fluorescing DOM in both unburned and char layers. Similarity between two EEMs indices (Fluorescence and Freshness), further denote that unburned soils and char layers originate from the same source and are consistent with visual evidence char layers contain significant amounts of unaltered OM. However, the EEMs humification index (HIX) and compositional analysis with pyrolysis GCMS

  12. Composite anode for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    de Guzman, Rhet C.; Ng, K.Y. Simon; Salley, Steven O.

    2018-03-06

    A composite anode for a lithium-ion battery is manufactured from silicon nanoparticles having diameters mostly under 10 nm; providing an oxide layer on the silicon nanoparticles; dispersing the silicon nanoparticles in a polar liquid; providing a graphene oxide suspension; mixing the polar liquid containing the dispersed silicone nanoparticles with the graphene oxide suspension to obtain a composite mixture; probe-sonicating the mixture for a predetermined time; filtering the composite mixture to obtain a solid composite; drying the composite; and reducing the composite to obtain graphene and silicon.

  13. comparative proximate composition and antioxidant vitamins

    African Journals Online (AJOL)

    DR. AMINU

    Keywords: Comparative, proximate composition, antioxidant vitamins, honey. INTRODUCTION ... solution of inverted sugars and complex mixture of other saccharides ... enzymatic browning in apple slices and grape juice. (Khan, 1985).

  14. Structural properties of dendrimer-colloid mixtures

    International Nuclear Information System (INIS)

    Lenz, Dominic A; Blaak, Ronald; Likos, Christos N

    2012-01-01

    We consider binary mixtures of colloidal particles and amphiphilic dendrimers of the second generation by means of Monte Carlo simulations. By using the effective interactions between monomer-resolved dendrimers and colloids, we compare the results of simulations of mixtures stemming from a full monomer-resolved description with the effective two-component description at different densities, composition ratios, colloid diameters and interaction strengths. Additionally, we map the two-component system onto an effective one-component model for the colloids in the presence of the dendrimers. Simulations based on the resulting depletion potentials allow us to extend the comparison to yet another level of coarse graining and to examine under which conditions this two-step approach is valid. In addition, a preliminary outlook into the phase behavior of this system is given. (paper)

  15. Radiation hardenable coating mixture

    International Nuclear Information System (INIS)

    Howard, D.D.

    1977-01-01

    This invention relates to coatings that harden under radiation and to their compositions. Specifically, this invention concerns unsaturated urethane resins polymerisable by addition and to compositions, hardening under the effect of radiation, containing these resins. These resins feature the presence of at least one unsaturated ethylenic terminal group of structure CH 2 =C and containing the product of the reaction of an organic isocyanate compound with at least two isocyanate groups and one polyester polyol with at least two hydroxyl groups, and one unsaturated monomer compound polymerisable by addition having a single active hydrogen group reacting with the isocyanate [fr

  16. Research of Deformation of Clay Soil Mixtures Mixtures

    OpenAIRE

    Romas Girkontas; Tadas Tamošiūnas; Andrius Savickas

    2014-01-01

    The aim of this article is to determine clay soils and clay soils mixtures deformations during drying. Experiments consisted from: a) clay and clay mixtures bridges (height ~ 0,30 m, span ~ 1,00 m); b) tiles of clay and clay, sand and straw (height, length, wide); c) cylinders of clay; clay and straw; clay, straw and sand (diameter; height). According to the findings recommendations for clay and clay mixtures drying technology application were presented. During the experiment clay bridge bear...

  17. Mutagenicity of complex mixtures

    International Nuclear Information System (INIS)

    Pelroy, R.A.

    1985-01-01

    The effect of coal-derived complex chemical mixtures on the mutagenicity of 6-aminochrysene (6-AC) was determined with Salmonella typhimurium TA98. Previous results suggested that the mutagenic potency of 6-AC for TA98 in the standard microsomal activation (Ames) assay increased if it was presented to the cells mixed with high-boiling coal liquids (CL) from the solvent refined coal (SRC) process. In this year's work, the apparent mutational synergism of CL and 6-AC was independently verified in a fluctuation bioassay which allowed quantitation of mutational frequencies and cell viability. The results of this assay system were similar to those in the Ames assay. Moreover, the fluctation assay revealed that mutagenesis and cellular toxicity induced by 6-AC were both strongly enhanced if 6-AC was presented to the cells mixed in a high-boiling CL. 4 figures

  18. Environmentally relevant chemical mixtures of concern in waters of United States tributaries to the Great Lakes

    Science.gov (United States)

    Elliott, Sarah M.; Brigham, Mark E.; Kiesling, Richard L.; Schoenfuss, Heiko L.; Jorgenson, Zachary G.

    2018-01-01

    The North American Great Lakes are a vital natural resource that provide fish and wildlife habitat, as well as drinking water and waste assimilation services for millions of people. Tributaries to the Great Lakes receive chemical inputs from various point and nonpoint sources, and thus are expected to have complex mixtures of chemicals. However, our understanding of the co‐occurrence of specific chemicals in complex mixtures is limited. To better understand the occurrence of specific chemical mixtures in the US Great Lakes Basin, surface water from 24 US tributaries to the Laurentian Great Lakes was collected and analyzed for diverse suites of organic chemicals, primarily focused on chemicals of concern (e.g., pharmaceuticals, personal care products, fragrances). A total of 181 samples and 21 chemical classes were assessed for mixture compositions. Basin wide, 1664 mixtures occurred in at least 25% of sites. The most complex mixtures identified comprised 9 chemical classes and occurred in 58% of sampled tributaries. Pharmaceuticals typically occurred in complex mixtures, reflecting pharmaceutical‐use patterns and wastewater facility outfall influences. Fewer mixtures were identified at lake or lake‐influenced sites than at riverine sites. As mixture complexity increased, the probability of a specific mixture occurring more often than by chance greatly increased, highlighting the importance of understanding source contributions to the environment. This empirically based analysis of mixture composition and occurrence may be used to focus future sampling efforts or mixture toxicity assessments. 

  19. Skin barrier composition

    International Nuclear Information System (INIS)

    Osburn, F.G.

    1985-01-01

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices. (author)

  20. Skin barrier composition

    Energy Technology Data Exchange (ETDEWEB)

    Osburn, F G

    1985-06-12

    A skin barrier composition comprises a mixture of a copolymer resin of ethylene and vinyl acetate (EVA), and a water-insoluble dry tack-providing elastomer such as polyisobutylene. The composition after mixing and molding, is subjected to ionizing irradiation to form cross-linked polymer networks of the EVA. The compositions have exceptional properties for use as barrier sheets, rings, or strips in ostomy, wound drainage, and incontinence devices.

  1. Pycnonuclear reaction rates for binary ionic mixtures

    Science.gov (United States)

    Ichimaru, S.; Ogata, S.; Van Horn, H. M.

    1992-01-01

    Through a combination of compositional scaling arguments and examinations of Monte Carlo simulation results for the interparticle separations in binary-ionic mixture (BIM) solids, we have derived parameterized expressions for the BIM pycnonuclear rates as generalizations of those in one-component solids obtained previously by Salpeter and Van Horn and by Ogata et al. We have thereby discovered a catalyzing effect of the heavier elements, which enhances the rates of reactions among the lighter elements when the charge ratio exceeds a critical value of approximately 2.3.

  2. Complex mixtures biostudies

    International Nuclear Information System (INIS)

    Springer, D.L.

    1987-01-01

    The objective of the project is to identify potential adverse biological activities associated with human exposures to complex organic mixtures (COM) from energy-related industries. Studies to identify the influence of chemical class fractions from a COM on the initiating activity of a known carcinogen, benzo(a)pyrene (BaP), demonstrated that the polycyclic aromatic hydrocarbons (PAH) and nitrogen-containing polycyclic aromatic compound (NPAC) fractions were the most effective inhibitors of initiation. In an effort to determine the contribution of BaP to the initiating activity of the COM, binding of radiolabeled BaP to mouse skin DNA was measured. Results indicated that binding of BaP to DNA decreased in the presence of the COM so that at initiating COM doses, BaP binding was near the limit detection. Addition of unlabeled BaP to the COM at an amount similar to that originally present in the COM did not significantly increase the binding. Studies to determine the rates of disappearance of carcinogenic PAH from the site of application on the skin indicated that half-lives for PAH differed by a factor of about 2. Analytical methods developed to identify PAH from COM which covalently bind to DNA demonstrated that the lower level of detection is approximately 200 picograms. Developmental studies demonstrated that both pregnant rats and mice treated dermally with a high-boiling COM developed fetuses with major malformations including cleft palate, small lungs, edema, and sagittal suture hemorrhages. 3 figures, 5 tables

  3. Fire-mediated dieback and compositional cascade in an Amazonian forest.

    Science.gov (United States)

    Barlow, Jos; Peres, Carlos A

    2008-05-27

    The only fully coupled land-atmosphere global climate model predicts a widespread dieback of Amazonian forest cover through reduced precipitation. Although these predictions are controversial, the structural and compositional resilience of Amazonian forests may also have been overestimated, as current vegetation models fail to consider the potential role of fire in the degradation of forest ecosystems. We examine forest structure and composition in the Arapiuns River basin in the central Brazilian Amazon, evaluating post-fire forest recovery and the consequences of recurrent fires for the patterns of dominance of tree species. We surveyed tree plots in unburned and once-burned forests examined 1, 3 and 9 years after an unprecedented fire event, in twice-burned forests examined 3 and 9 years after fire and in thrice-burned forests examined 5 years after the most recent fire event. The number of trees recorded in unburned primary forest control plots was stable over time. However, in both once- and twice-burned forest plots, there was a marked recruitment into the 10-20cm diameter at breast height tree size classes between 3 and 9 years post-fire. Considering tree assemblage composition 9 years after the first fire contact, we observed (i) a clear pattern of community turnover among small trees and the most abundant shrubs and saplings, and (ii) that species that were common in any of the four burn treatments (unburned, once-, twice- and thrice-burned) were often rare or entirely absent in other burn treatments. We conclude that episodic wildfires can lead to drastic changes in forest structure and composition, with cascading shifts in forest composition following each additional fire event. Finally, we use these results to evaluate the validity of the savannization paradigm.

  4. Component effects in mixture experiments

    International Nuclear Information System (INIS)

    Piepel, G.F.

    1980-01-01

    In a mixture experiment, the response to a mixture of q components is a function of the proportions x 1 , x 2 , ..., x/sub q/ of components in the mixture. Experimental regions for mixture experiments are often defined by constraints on the proportions of the components forming the mixture. The usual (orthogonal direction) definition of a factor effect does not apply because of the dependence imposed by the mixture restriction, /sup q/Σ/sub i=1/ x/sub i/ = 1. A direction within the experimental region in which to compute a mixture component effect is presented and compared to previously suggested directions. This new direction has none of the inadequacies or errors of previous suggestions while having a more meaningful interpretation. The distinction between partial and total effects is made. The uses of partial and total effects (computed using the new direction) in modification and interpretation of mixture response prediction equations are considered. The suggestions of the paper are illustrated in an example from a glass development study in a waste vitrification program. 5 figures, 3 tables

  5. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon; Ryu, Duchwan; Mallick, Bani K.; Genton, Marc G.

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class

  6. Easy and flexible mixture distributions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Mabit, Stefan L.

    2013-01-01

    We propose a method to generate flexible mixture distributions that are useful for estimating models such as the mixed logit model using simulation. The method is easy to implement, yet it can approximate essentially any mixture distribution. We test it with good results in a simulation study...

  7. Method of separation of gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Berlin, M.A.; Potapov, V.F.; Potapova, M.S.

    1980-04-05

    Gas mixtures are separated in a rectification tower by repeated counterflow contact of the heated gas flow and cool condensate as the pressure drops in each stage of separation (StR) and when condensate is added from StR with lower pressure to the StR with higher pressure. In order to reduce energy consumption noncondensing gas in amounts of 5-15 percent by weight of the amount of incoming gases are added. Hydrocarbon or carbon dioxide gas can be used as the latter. Example. To separate natural gas of the Shatlyk deposit of composition, percent by mo1: C1 -- 94.960; C2 -- 4.260; C3 -- 0.200; C4 -- 0.08; C4+B -- 0.51. It is enriched with carbon dioxide gas in an amount of 10 percent by weight. Upon rectification of the enriched hydrocarbon mixture separation is achieved at lower pressures of the gas mixture and less cold. This leads to reduction of energy consumption by 10-12 percent.

  8. Chemometrics as a tool to analyse complex chemical mixtures

    DEFF Research Database (Denmark)

    Christensen, J. H.

    Chemical characterisation of contaminant mixtures is important for environmental forensics and risk assessment. The great challenge in future research lies in develop- ing suitable, rapid, reliable and objective methods for analysis of the composition of complex chemical mixtures. This thesis...... describes the development of such methods for assessing the identity (chemical fingerprinting) and fate (e.g. biodegradation) of petroleum hydrocarbon mixtures. The methods comply with the general concept that suitable methods must be rapid and inexpensive, objective with limited human in- tervention...... and at the same time must consider a substantial fraction of compounds in the complex mixture. A combination of a) limited sample preparation, b) rapid chemical screening analysis, c) fast and semi-automatic pre-processing, d) compre- hensive multivariate statistical data analysis and e) objective data evaluation...

  9. A Variational Statistical-Field Theory for Polar Liquid Mixtures

    Science.gov (United States)

    Zhuang, Bilin; Wang, Zhen-Gang

    Using a variational field-theoretic approach, we derive a molecularly-based theory for polar liquid mixtures. The resulting theory consists of simple algebraic expressions for the free energy of mixing and the dielectric constant as functions of mixture composition. Using only the dielectric constants and the molar volumes of the pure liquid constituents, the theory evaluates the mixture dielectric constants in good agreement with the experimental values for a wide range of liquid mixtures, without using adjustable parameters. In addition, the theory predicts that liquids with similar dielectric constants and molar volumes dissolve well in each other, while sufficient disparity in these parameters result in phase separation. The calculated miscibility map on the dielectric constant-molar volume axes agrees well with known experimental observations for a large number of liquid pairs. Thus the theory provides a quantification for the well-known empirical ``like-dissolves-like'' rule. Bz acknowledges the A-STAR fellowship for the financial support.

  10. Petroleum Diesel Fuel and Linseed Oil Mixtures as Engine Fuels

    Science.gov (United States)

    Markov, V. A.; Kamaltdinov, V. G.; Savastenko, A. A.

    2018-01-01

    The actual problem is the use of alternative biofuels in automotive diesel engines. Insufficiently studied are the indicators of toxicity of exhaust gases of these engines operating on biofuel. The aim of the study is to identify indicators of the toxicity of exhaust gases when using of petroleum diesel fuel and linseed oil mixtures as a fuel for automotive diesel engines. Physical and chemical properties of linseed oil and its mixtures with petroleum diesel fuel are considered. Experimental researches of D-245.12C diesel are carried out on mixtures of diesel fuel and corn oil with a different composition. An opportunity of exhaust toxicity indexes improvement using these mixtures as a fuel for automobiles engine is shown.

  11. Co-pyrolysis of wood biomass and synthetic polymers mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sharypov, V.I.; Beregovtsova, N.G.; Kuznetsov, B.N.; Baryshnikov, S.V. [Institute of Chemistry and Chemical Technology SB RAS, K. Marx Str., Krasnoyarsk 660049 (Russian Federation); Cebolla, V.L. [Instituto de Carboquimica, CSIC, Zaragoza (Spain); Weber, J.V.; Collura, S.; Finqueneisel, G.; Zimny, T. [Laboratoire de Chimie et Applications, Universite de Metz, IUT, rue V. Demange, 57500 Saint Avold (France)

    2006-06-01

    The pyrolysis in a hydrogen atmosphere of pine wood and synthetic polymers (polyethylene and polypropylene) mixtures was studied in a rotating autoclave. The effects of reaction temperature, wood/polymers mixture composition and catalysts, on the mixtures conversion into liquids and gases were established and discussed. The used catalysts were pyrrhotite and haematite materials activated by mechanochemical treatment. In the co-liquefaction processes the interaction between fragments of wood and polymers thermal decomposition took place. This results in non-additive increase of the wood/polymers conversion degree by 10-15wt.% and of the yield of distillate fractions by 14-19wt.%. Iron ore materials were found catalytically active in the process of hydropyrolysis of wood/polymers mixtures. By using these catalysts a significant increase of the distillable liquids amounts (by 14-21wt.%) and a sharp decrease of olefins and cycloparaffins content (by approximately two to three times) were observed. (author)

  12. Water-bearing explosive compositions

    Energy Technology Data Exchange (ETDEWEB)

    Gay, G M

    1970-12-21

    An explosive water-bearing composition, with high detonation velocity, comprises a mixture of (1) an inorganic oxidizer salt; (2) nitroglycerine; (3) nitrocellulose; (4) water; and (5) a water thickening agent. (11 claims)

  13. Thermodynamics of liquid mixtures of methane and ethene

    Energy Technology Data Exchange (ETDEWEB)

    Calado, J C.G.; Soares, V A.M.

    1977-08-01

    Experiments conducted by Portugal's Instituto Superior Tecnico provide liquid and vapor equilibrium compositions and pressures for the methane-ethene system at 103.94 and -115.77 K as well as the molar volumes of the mixtures at the lower temperature. From the results, researchers estimated the excess Gibbs energies at these tempertures and the molar enthalpy of mixing.

  14. Thermodynamics of liquid mixtures of methane and ethene

    Energy Technology Data Exchange (ETDEWEB)

    Calado, J.C.G.; Soares, V.A.M.

    1977-08-01

    Experiments conducted by Portugal's Instituto Superior Tecnico provide liquid and vapor equilibrium compositions and pressures for the methane-ethene system at 103.94 and -115.77 K as well as the molar volumes of the mixtures at the lower temperature. From the results, researchers estimated the excess Gibbs energies at these tempertures and the molar enthalpy of mixing.

  15. 3.4. Durability of soil-cement mixtures influenced by hostile environment

    International Nuclear Information System (INIS)

    Saidov, D.Kh.

    2011-01-01

    It is determined that soil-cement mixture is one of most perspective materials, that can substitute concrete. Experiments on revelation of magnesium sulphate influence on soil-cement mixtures were carried out. Data on granulometric composition and physical parameters of loess soils is presented in this article. Portland cement M 400 was used as binder. According to the results it is concluded that stability of soil-cement mixtures from loess soils in solutions of magnesium sulphate depends on concentration of solution.

  16. Diffusion in Poiseuille and Couette flows of binary mixtures of incompressible newtonian fluids

    International Nuclear Information System (INIS)

    Caetano Filho, E.; Qassim, R.Y.

    1981-07-01

    Using the continuum theory of binary mixtures of incompressible Newtonian fluids, Poiseuille and Couette flows are studied with a view to determining whether diffusion occurs in such flows. It is shown that diffusion is absent in the Couette case. However, in Poiseuille flow there are significant differences between the velocities of the species comprising the mixture. This result is in broad agreement with that of Mills for similar mixtures of nonuniform composition. (Author) [pt

  17. Thermal Signature Measurements for Ammonium Nitrate/Fuel Mixtures by Laser Heating.

    Science.gov (United States)

    Nazarian, Ashot; Presser, Cary

    2016-01-10

    Measurements were carried out to obtain thermal signatures of several ammonium nitrate/fuel (ANF) mixtures, using a laser-heating technique referred to as the laser-driven thermal reactor (LDTR). The mixtures were ammonium nitrate (AN)/kerosene, AN/ethylene glycol, AN/paraffin wax, AN/petroleum jelly, AN/confectioner's sugar, AN/cellulose (tissue paper), nitromethane/cellulose, nitrobenzene/cellulose, AN/cellulose/nitromethane, AN/cellulose/nitrobenzene. These mixtures were also compared with AN/nitromethane and AN/diesel fuel oil, obtained from an earlier investigation. Thermograms for the mixtures, as well as individual constituents, were compared to better understand how the sample thermal signature changes with mixture composition. This is the first step in development of a thermal-signature database, to be used along with other signature databases, to improve identification of energetic substances of unknown composition. The results indicated that each individual thermal signature was associated unambiguously with a particular mixture composition. The signature features of a particular mixture were shaped by the individual constituent signatures. It was also uncovered that the baseline signature was modified after an experiment due to coating of unreacted residue on the substrate surface and a change in the reactor sphere oxide layer. Thus, care was required to pre-oxidize the sphere prior to an experiment. A minimum sample mass (which was dependent on composition) was required to detect the signature characteristics. Increased laser power served to magnify signal strength while preserving the signature features. For the mixtures examined, the thermal response of each ANF mixture was found to be different, which was based on the mixture composition and the thermal behavior of each mixture constituent.

  18. Acrylic composition

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Meda, Yutaka.

    1969-01-01

    An acrylic composition and a process for the production of an easily hardenable coating material by irradiating with active energy, particularly electron beams and ultraviolet light, are provided using a mixture of 10%-100% by weight of an unsaturated compound and 90%-0% of a vinyl monomer. The composition has a high degree of polymerization, low volatility, low viscosity and other properties similar to thermosetting acrylic or amino alkyd resins. The aforesaid unsaturated compound is produced by primarily reacting saturated cyclocarboxylic anhydride and/or alpha-, beta-ethylene unsaturated carboxylic anhydride and by secondarily reacting an epoxy radical-containing vinyl monomer by addition reaction with polyhydric alcohols. Each reaction is conducted in the presence of a tertiary amino radical-containing vinyl monomer as a catalyst. The cross-linking is effected generally with an electron beam accelerator of 0.1-2.0 MeV or with a light beam in the 2,000-8,000A range in the presence of a photosensitive agent. In one example, 62 parts of ethylene glycol and 196 parts of maleic anhydride were dissolved in a mixture consisting of 100 parts of n-butyl methacrylate and 30 parts of styrene. To the mixture were added 5 parts of 2-methyl 5 vinyl piridine and 0.005 part of hydroquinone monomethyl ether. After the reaction at 90 0 C for 3 hours, a compound HOC:O-CH=CHC:OCH 2 CH 2 C:OOH was produced. To this solution were added 285 parts of glycidyl methacrylate. After the reaction at 90 0 C for 6 hours, 95% of the carboxylic acids reacted with epoxy radicals. Fourteen examples are given. (Iwakiri, K.)

  19. NO{sub x} emissions from combustion of hydrogen mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Roertveit, Geir Johan

    2002-07-01

    to 1800 K the importance of the prompt NO{sub x} mechanism is verified for the porous burners that are burning hydrocarbon fuels. A catalytical burner system has been designed and tested. The system uses Labview for improved mass flow control and the logging of all measurements. Commercial catalysts with Pt and Pt/Pd are used and were found to completely oxidise lean mixtures of H{sub 2} in air. Due to the low temperatures no NO{sub x} emissions were recorded. The initial temperature requirements for igniting CH{sub 4} and C{sub 3}H{sub 8} in these catalytic burners was met by preheating, CO, or H{sub 2} oxidation. C{sub 3}H{sub 8} was found to be far easier to ignite than CH{sub 4}. After the ignition of either hydrocarbon fuel at above 1170 K, it was possible to switch over to either of the pure hydrocarbon fuels. Complete combustion at temperatures of up to 1270 K gave emissions for NO{sub x}, CO and unburned hydrocarbons of less than 3 ppm corrected to 3 % O{sub 2} in the flue gases. The limitation of these catalytic burners is the durability of the catalytic materials and when a temperature of about 1320 K is exceeded for periods of time, there was a permanent loss of activity. An 8 hour long term test indicated a loss of activity by a factor of about 4. This led to the development of a catalytically supported porous burner, where the temperature at the catalyst could be kept low. However, this burner did not further lower the emissions values compared to a regular porous burner. (Author)

  20. Hydrogen-water vapor mixtures: Control of hydrothermal atmospheres by hydrogen osmosis

    Science.gov (United States)

    Shaw, H.R.

    1963-01-01

    Experiments at 700??C and 800 bars total pressure demonstrate positive deviations from ideality for mixtures of hydrogen and H2O gases. The deviations are greater than predicted with Stockmayer's method. The composition of the mixture and the fugacity of hydrogen are controlled by diffusing hydrogen through metallic membranes. The results give the fugacities of both H 2O and oxygen.

  1. Vertical vs Lateral Macrophase Separation in Thin Films of Block Copolymer Mixtures

    DEFF Research Database (Denmark)

    Berezkin, Anatoly V.; Jung, Florian; Posselt, Dorthe

    2017-01-01

    Mixtures of two diblock copolymers of very different lengths may feature both macro- and microphase separation; however, not much is known about the mechanisms of separation in diblock copolymer thin films. In the present work, we study thin films of mixtures of two compositionally symmetric bloc...

  2. Natural convection in ternary mixtures

    International Nuclear Information System (INIS)

    Kremer, G.M.; Kai, L.

    1981-01-01

    The field equations for a mixture of a viscous fluid, a deformable solid and a non-viscous fluid are studied, based on a linearized theory proposed by Bowen. The fields of density of each constituent, temperature, velocity of each fluid and displacement of the solid are determined, for steady states flow of the mixture between two parallel planes and between two concentric cylinders which are maintained at diferent temperatures. (Author) [pt

  3. Centrifugal separation of mixture gases

    International Nuclear Information System (INIS)

    Zhou, M.S.; Chen, W.N.; Yin, Y.T.

    2008-01-01

    An attempt for single centrifugal separation of mixtures with different molecular formula was presented in this paper. The mixtures of SF 6 and CCl 3 F, and SF 6 and CCl 4 were chosen as the processing gases, which were prepared in three mass ratios, 0.5, 0.8 and 0.2, respectively. The separating characteristics such as the overall separation factors and the variation of cuts were studied. (author)

  4. Strongly correlated Fermi-Bose mixtures in disordered optical lattices

    International Nuclear Information System (INIS)

    Sanchez-Palencia, L; Ahufinger, V; Kantian, A; Zakrzewski, J; Sanpera, A; Lewenstein, M

    2006-01-01

    We investigate theoretically the low-temperature physics of a two-component ultracold mixture of bosons and fermions in disordered optical lattices. We focus on the strongly correlated regime. We show that, under specific conditions, composite fermions, made of one fermion plus one bosonic hole, form. The composite picture is used to derive an effective Hamiltonian whose parameters can be controlled via the boson-boson and the boson-fermion interactions, the tunnelling terms and the inhomogeneities. We finally investigate the quantum phase diagram of the composite fermions and show that it corresponds to the formation of Fermi glasses, spin glasses and quantum percolation regimes

  5. Strongly correlated Fermi-Bose mixtures in disordered optical lattices

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Palencia, L [Laboratoire Charles Fabry de l' Institut d' Optique, CNRS and Universite Paris-Sud XI, Bat 503, Centre scientifique, F-91403 Orsay Cedex (France); Ahufinger, V [ICREA and Grup d' optica, Departament de FIsica, Universitat Autonoma de Barcelona, E-08193 Belaterra (Barcelona) (Spain); Kantian, A [Institut fuer Theoretische Physik, Universitaet Innsbruck, A-6020 Innsbruck (Austria); Zakrzewski, J [Instytut Fizyki imienia Mariana Smoluchowskiego i Centrum Badan Ukladow Zlozonych imienia Marka Kaca, Uniwersytet Jagiellonski, ulica Reymonta 4, PL-30-059 Krakow (Poland); Sanpera, A [ICREA and Grup de FIsica Teorica, Departament de FIsica, Universitat Autonoma de Barcelona, E-08193 Belaterra (Barcelona) (Spain); Lewenstein, M [ICREA and ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la TecnologIa, E-08860 Castelldefels (Barcelona) (Spain); Institut fuer Theoretische Physik, Universitaet Hannover, D-30167 Hannover (Germany)

    2006-05-28

    We investigate theoretically the low-temperature physics of a two-component ultracold mixture of bosons and fermions in disordered optical lattices. We focus on the strongly correlated regime. We show that, under specific conditions, composite fermions, made of one fermion plus one bosonic hole, form. The composite picture is used to derive an effective Hamiltonian whose parameters can be controlled via the boson-boson and the boson-fermion interactions, the tunnelling terms and the inhomogeneities. We finally investigate the quantum phase diagram of the composite fermions and show that it corresponds to the formation of Fermi glasses, spin glasses and quantum percolation regimes.

  6. Modeling Hydrodynamic State of Oil and Gas Condensate Mixture in a Pipeline

    Directory of Open Access Journals (Sweden)

    Dudin Sergey

    2016-01-01

    Based on the developed model a calculation method was obtained which is used to analyze hydrodynamic state and composition of hydrocarbon mixture in each ith section of the pipeline when temperature-pressure and hydraulic conditions change.

  7. Performance evaluation of Louisiana superpave mixtures.

    Science.gov (United States)

    2008-12-01

    This report documents the performance of Louisiana Superpave mixtures through laboratory mechanistic tests, mixture : volumetric properties, gradation analysis, and early field performance. Thirty Superpave mixtures were evaluated in this : study. Fo...

  8. Forage intake and botanical composition of feed for cattle fed Brachiaria/legume mixtures Consumo e composição da forragem ingerida por bovinos alimentados com Brachiaria e uma leguminosa

    Directory of Open Access Journals (Sweden)

    Robert Macedo

    2010-08-01

    Full Text Available A key contribution to study the cycling of nutrients in soil/plant/animal systems is the evaluation of the consumption of forage and their nutrients by cattle. The objective of this study was to test techniques to evaluate faecal production, in vitro digestibility, forage consumption and the proportion of legume in the acquired diet. Five Zebu steer calves were confined and fed five diets of different combinations of Brachiaria dictyoneura and Desmodium ovalifolium. All quantities of faeces were collected per animal and these values were found to compare favourably with those derived from using the chromium oxide technique. In vitro digestibility ranged from 7 to 10% higher than the actual in vivo digestibility. Faecal samples from steers fed with diets with 25% or more of grass in the mixture were found to be depleted in δ13C between 1.7 and 2.1‰, but no depletion was observed when the diet was 100% D. ovalifolium. There was a positive linear regression (r² = 0.97*** of the δ13C of the diet with the δ13C of faeces, but if the acquired diet contained a very high proportion of legume, the legume content could be underestimated by as much as 10%. None of the internal indicators, such as lignin or ash content of the diets, were useful to predict feed intake, but the chromium oxide external indicator performed satisfactorily. The 13C analysis of the faeces was an effective predictor of the proportion of the legume in the consumed diet.Uma contribuição fundamental para o estudo da ciclagem de nutrientes no sistema solo/planta/ animal é a avaliação do consumo pelo gado de forragem e dos nutrientes nela contidos. Testaram-se, sob condições controladas, técnicas para avaliar a produção fecal, digestibilidade in vitro, consumo de forragem e a proporção de leguminosa ingerida na dieta. Cinco novilhos de Zebu foram confinados e alimentados com quantidades conhecidas de cinco rações com diferentes proporções de Brachiaria dictyoneura e

  9. Effects of Mixture Stratification on Combustion and Emissions of Boosted Controlled Auto-Ignition Engines

    Directory of Open Access Journals (Sweden)

    Jacek Hunicz

    2017-12-01

    Full Text Available The stratification of in-cylinder mixtures appears to be an effective method for managing the combustion process in controlled auto-ignition (CAI engines. Stratification can be achieved and controlled using various injection strategies such as split fuel injection and the introduction of a portion of fuel directly before the start of combustion. This study investigates the effect of injection timing and the amount of fuel injected for stratification on the combustion and emissions in CAI engine. The experimental research was performed on a single cylinder engine with direct gasoline injection. CAI combustion was achieved using negative valve overlap and exhaust gas trapping. The experiments were performed at constant engine fueling. Intake boost was applied to control the excess air ratio. The results show that the application of the late injection strategy has a significant effect on the heat release process. In general, the later the injection is and the more fuel is injected for stratification, the earlier the auto-ignition occurs. However, the experimental findings reveal that the effect of stratification on combustion duration is much more complex. Changes in combustion are reflected in NOX emissions. The attainable level of stratification is limited by the excessive emission of unburned hydrocarbons, CO and soot.

  10. Determinação das composições físico-químicas de cachaças do sul de minas gerais e de suas misturas Determination of the physical-chemical composition of homemade cachaças produced in the South of Minas Gerais and their mixtures

    Directory of Open Access Journals (Sweden)

    Fernando José Vilela

    2007-08-01

    Full Text Available Este trabalho teve por objetivo a determinação da composição físico-química de cachaças artesanais produzidas no sul do Estado de Minas Gerais e suas misturas. Foram analisados os teores de etanol, acidez volátil, aldeídos, cobre, ésteres, álcoois superiores totais e metanol, além dos álcoois propanol-1, isobutanol e 3-metil-butanol-1. Os resultados apresentam o perfil peculiar desta bebida, que apresentou teores satisfatórios de álcoois superiores, ésteres e aldeídos. O teor de cobre apresenta-se como preocupante já que algumas amostras excederam o limite de 5 mg.L-1. A produção de misturas foi estudada e esta apresenta-se como uma alternativa viável ao produtor e cooperativas.The present study sought the physical-chemical composition of homemade cachaças produced in the south of the state Minas Gerais and of mixtures of the same cachaça samples. The ethanol, aldehyde, copper, higher alcohol, volatile acid and methanol concentrations were determined, in addition to the individual propanol, 2-methyl-1-propanol and 3-methyl-1-butanol concentrations. The results demonstrated the characteristic profile of this beverage, which presented satisfactory concentrations of higher alcohols, esters, and aldehydes. The copper concentrations of some samples exceeded the limit of 5 mg. L-1. The mixtures produced from some of the cachaça samples presented a viable alternative for the producers and cooperatives because the concentrations of the components were more adequate for exportation.

  11. Concrete mixtures with high-workability for ballastless slab tracks

    Directory of Open Access Journals (Sweden)

    Olga Smirnova

    2017-10-01

    Full Text Available The concrete track-supporting layer and the monolithic concrete slab of ballastless track systems are made in-situ. For this reason the concrete mixtures of high workability should be used. Influence of the sand kind, the quartz microfiller fineness and quantity as well as quantity of superplasticizer on workability of fresh concrete and durability of hardened concrete is shown. The compositions of the high-workability concrete mixtures with lower consumption of superplasticizer are developed. The results of the research can be recommended for high performance concrete of ballastless slab track.

  12. Self-compacting concrete mixtures for road BUILDING

    Directory of Open Access Journals (Sweden)

    Tran Tuan My

    2012-10-01

    Therefore, effective concrete road pavements require self-compacting though non-segregating concrete mixtures to comply with the pre-set values of their properties, namely, bending and compressive strength, corrosion resistance, freeze resistance, etc. Acting in cooperation with Department of Technology of Binders and Concretes of MSUCE, NIIMosstroy developed and examined a self-compacting cast concrete mixture designated for durable monolithic road pavements. The composition in question was generated by adding a multi-component modifier into the mix. The modifier was composed of a hyperplasticiser, active (structureless fine and crystalline silica, and a concrete hardening control agent.

  13. Solidification of radioactive waste in a cement/lime mixture

    International Nuclear Information System (INIS)

    Zhou, H.; Colombo, P.

    1984-01-01

    The suitability of a cement/lime mixture for use as a solidification agent for different types of wastes was investigated. This work includes studies directed towards determining the wasted/binder compositional field over which successful solidification occurs with various wastes and the measurement of some of the waste from properties relevant to evaluating the potential for the release of radionuclides to the environment. In this study, four types of low-level radioactive wastes were simulated for incorporation into a cement/lime mixture. These were boric acid waste, sodium sulfate wastes, aion exchange resins and incinerator ash. 7 references, 3 figures, 2 tables

  14. Nonparametric e-Mixture Estimation.

    Science.gov (United States)

    Takano, Ken; Hino, Hideitsu; Akaho, Shotaro; Murata, Noboru

    2016-12-01

    This study considers the common situation in data analysis when there are few observations of the distribution of interest or the target distribution, while abundant observations are available from auxiliary distributions. In this situation, it is natural to compensate for the lack of data from the target distribution by using data sets from these auxiliary distributions-in other words, approximating the target distribution in a subspace spanned by a set of auxiliary distributions. Mixture modeling is one of the simplest ways to integrate information from the target and auxiliary distributions in order to express the target distribution as accurately as possible. There are two typical mixtures in the context of information geometry: the [Formula: see text]- and [Formula: see text]-mixtures. The [Formula: see text]-mixture is applied in a variety of research fields because of the presence of the well-known expectation-maximazation algorithm for parameter estimation, whereas the [Formula: see text]-mixture is rarely used because of its difficulty of estimation, particularly for nonparametric models. The [Formula: see text]-mixture, however, is a well-tempered distribution that satisfies the principle of maximum entropy. To model a target distribution with scarce observations accurately, this letter proposes a novel framework for a nonparametric modeling of the [Formula: see text]-mixture and a geometrically inspired estimation algorithm. As numerical examples of the proposed framework, a transfer learning setup is considered. The experimental results show that this framework works well for three types of synthetic data sets, as well as an EEG real-world data set.

  15. Curing kinetics of alkyd/melamine resin mixtures

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana C.

    2009-01-01

    Full Text Available Alkyd resins are the most popular and useful synthetic resins applied as the binder in protective coatings. Frequently they are not used alone but are modified with other synthetic resins in the manufacture of the coatings. An alkyd/melamine resin mixture is the usual composition for the preparation of coating called 'baking enamel' and it is cured through functional groups of resins at high temperatures. In this paper, curing kinetics of alkyd resins based on castor oil and dehydrated castor oil with melamine resin, has been studied by DSC method with programmed heating and in isothermal mode. The results determined from dynamic DSC curves were mathematically transformed using the Ozawa isoconversional method for obtaining the isothermal data. These results, degree of curing versus time, are in good agreement with those determined by the isothermal DSC experiments. By applying the Ozawa method it is possible to calculate the isothermal kinetic parameters for the alkyd/melamine resin mixtures curing using only calorimetric data obtained by dynamic DSC runs. Depending on the alkyd resin type and ratio in mixtures the values of activation energies of curing process of resin mixtures are from 51.3 to 114 kJ mol-1. The rate constant of curing increases with increasing the content of melamine resin in the mixture and with curing temperature. The reaction order varies from 1.12 to 1.37 for alkyd based on dehydrated castor oil/melamine resin mixtures and from 1.74 to 2.03 for mixtures with alkyd based on castor oil. Based on the results obtained, we propose that dehydrated castor oil alkyd/melamine resin mixtures can be used in practice (curing temperatures from 120 to 160°C.

  16. Nature and prevalence of non-additive toxic effects in industrially relevant mixtures of organic chemicals.

    Science.gov (United States)

    Parvez, Shahid; Venkataraman, Chandra; Mukherji, Suparna

    2009-06-01

    The concentration addition (CA) and the independent action (IA) models are widely used for predicting mixture toxicity based on its composition and individual component dose-response profiles. However, the prediction based on these models may be inaccurate due to interaction among mixture components. In this work, the nature and prevalence of non-additive effects were explored for binary, ternary and quaternary mixtures composed of hydrophobic organic compounds (HOCs). The toxicity of each individual component and mixture was determined using the Vibrio fischeri bioluminescence inhibition assay. For each combination of chemicals specified by the 2(n) factorial design, the percent deviation of the predicted toxic effect from the measured value was used to characterize mixtures as synergistic (positive deviation) and antagonistic (negative deviation). An arbitrary classification scheme was proposed based on the magnitude of deviation (d) as: additive (50%, class-IV) antagonistic/synergistic. Naphthalene, n-butanol, o-xylene, catechol and p-cresol led to synergism in mixtures while 1, 2, 4-trimethylbenzene and 1, 3-dimethylnaphthalene contributed to antagonism. Most of the mixtures depicted additive or antagonistic effect. Synergism was prominent in some of the mixtures, such as, pulp and paper, textile dyes, and a mixture composed of polynuclear aromatic hydrocarbons. The organic chemical industry mixture depicted the highest abundance of antagonism and least synergism. Mixture toxicity was found to depend on partition coefficient, molecular connectivity index and relative concentration of the components.

  17. Potential of organic Rankine cycle using zeotropic mixtures as working fluids for waste heat recovery

    International Nuclear Information System (INIS)

    Li, You-Rong; Du, Mei-Tang; Wu, Chun-Mei; Wu, Shuang-Ying; Liu, Chao

    2014-01-01

    The performance of the ORC (organic Rankine cycle) systems using zeotropic mixtures as working fluids for recovering waste heat of flue gas from industrial boiler is examined on the basis of thermodynamics and thermo-economics under different operating conditions. In order to explore the potential of the mixtures as the working fluids in the ORC, the effects of various mixtures with different components and composition proportions on the system performance have been analyzed. The results show that the compositions of the mixtures have an important effect on the ORC system performance, which is associated with the temperature glide during the phase change of mixtures. From the point of thermodynamics, the performance of the ORC system is not always improved by employing the mixtures as the working fluids. The merit of the mixtures is related to the restrictive conditions of the ORC, different operating conditions results in different conclusions. At a fixed pinch point temperature difference, the small mean heat transfer temperature difference in heat exchangers will lead to a larger heat transfer area and the larger total cost of the ORC system. Compared with the ORC with pure working fluids, the ORC with the mixtures presents a poor economical performance. - Highlights: • Organic Rankine cycle system with the mixture working fluids for recovering waste heat is analyzed. • The performance of the mixture-fluid ORC is related to temperature glide in phase change of mixture working fluids. • The relative merit of the mixture working fluids depends on the restrictive operation conditions of the ORC. • The ORC with mixture working fluid presents a poor economical performance compared with the pure working fluid case

  18. Use of Adhesion Promoters in Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Cihlářová Denisa

    2018-03-01

    Full Text Available The purpose of asphalt binder as a significant binder in road constructions is to permanently bind aggregates of different compositions and grain sizes. The asphalt binder itself does not have suitable adhesiveness, so after a period of time, bare grains can appear. This results in a gradual separation of the grains from an asphalt layer and the presence of potholes in a pavement. Adhesion promoters or adhesive agents are important and proven promoters in practice. They are substances mainly based on the fatty acids of polyamides which should increase the reliability of the asphalt’s binder adhesion to the aggregates, thus increasing the lifetime period of the asphalt mixture as well as its resistance to mechanical strain. The amount of a promoter or agent added to the asphalt mixture is negligible and constitutes about 0.3% of the asphalt’s binder weight. Nevertheless, even this quantity significantly increases the adhesive qualities of an asphalt binder. The article was created in cooperatation with the Slovak University of Technology, in Bratislava, Slovakia, and focuses on proving the new AD2 adhesive additive and comparing it with the Addibit and Wetfix BE promoters used on aggregates from the Skuteč - Litická and Bystřec quarries.

  19. Radiative otacity tables for 40 stellar mixtures

    International Nuclear Information System (INIS)

    Cox, A.N.; Tabor, J.E.

    1976-01-01

    Using improved methods, radiative opacities for 40 mixtures of elements are given for use in calculations of stellar structure, stellar evolution, and stellar pulsation. The major improvements over previous Los Alamos data are increased iron abundance in the composition, better allowance for the continuum depression for bound electrons, and corrections in some bound-electron energy levels. These opacities have already been widely used, and represent a relatively homogeneous set of data for stellar structures. Further improvements to include more bound-bound (line) transitions by a smearing technique and to include molecular absorptions are becoming available, and in a few years these tables, as well as all previous tables, will be outdated. At high densities the conduction of energy will dominate radiation flow, and this effect must be added separately

  20. Mixtures of skewed Kalman filters

    KAUST Repository

    Kim, Hyoungmoon

    2014-01-01

    Normal state-space models are prevalent, but to increase the applicability of the Kalman filter, we propose mixtures of skewed, and extended skewed, Kalman filters. To do so, the closed skew-normal distribution is extended to a scale mixture class of closed skew-normal distributions. Some basic properties are derived and a class of closed skew. t distributions is obtained. Our suggested family of distributions is skewed and has heavy tails too, so it is appropriate for robust analysis. Our proposed special sequential Monte Carlo methods use a random mixture of the closed skew-normal distributions to approximate a target distribution. Hence it is possible to handle skewed and heavy tailed data simultaneously. These methods are illustrated with numerical experiments. © 2013 Elsevier Inc.

  1. Preparation of conducting solid mixtures

    International Nuclear Information System (INIS)

    Spokas, J.J.

    1978-01-01

    The application of conducting plastic mixtures to the fundamental problem of radiation dosimetry is briefly reviewed. A particular approach to achieving formulations with the necessary characteristics is described. A number of successful mixtures are defined for a number of different specific dosimetry situations. To obtain high quality stable materials requires intense blending and working of the materials at elevated temperatures. One machine that succeeds in this task is the Shonka plastics mixer-extruder. The Shonka mixer is described in complete detail. The procedures used in preparing representative formulations with this device are presented. A number of properties of successful conducting mixtures so prepared are summarized. The conditions required for molding such material are given. Several special welding methods for specific application with these formulations have been devised and are described

  2. Bayesian Kernel Mixtures for Counts.

    Science.gov (United States)

    Canale, Antonio; Dunson, David B

    2011-12-01

    Although Bayesian nonparametric mixture models for continuous data are well developed, there is a limited literature on related approaches for count data. A common strategy is to use a mixture of Poissons, which unfortunately is quite restrictive in not accounting for distributions having variance less than the mean. Other approaches include mixing multinomials, which requires finite support, and using a Dirichlet process prior with a Poisson base measure, which does not allow smooth deviations from the Poisson. As a broad class of alternative models, we propose to use nonparametric mixtures of rounded continuous kernels. An efficient Gibbs sampler is developed for posterior computation, and a simulation study is performed to assess performance. Focusing on the rounded Gaussian case, we generalize the modeling framework to account for multivariate count data, joint modeling with continuous and categorical variables, and other complications. The methods are illustrated through applications to a developmental toxicity study and marketing data. This article has supplementary material online.

  3. Toxicology of Chemical Mixtures: A Review of Mixtures Assessment

    National Research Council Canada - National Science Library

    Bjarnason, Stephen

    2004-01-01

    .... Recent advances in disciplines such as genomics, proteomics, metabonomics and physiologically-based pharmacokinetic modeling should assist in the hazard assessment of complex chemical mixtures. However, the process of regulatory assessment of these types of exposures will remain both complex and difficult.

  4. Mixture Design and Its Application in Cement Solidification for Spent Resin

    International Nuclear Information System (INIS)

    Gan, Xueying; Lin, Meiqing; Chen, Hui

    1994-01-01

    The study is aimed to assess the usefulness of the mixture design for spent resin immobilization in cement. Although a considerable amount of research has been carried out to determine the limits for the composition of an acceptable resin-cement mixture, no efficient experimental strategy exists that explores the full properties of waste form against composition relationship. In order to gain an overall view, this report introduces the method of mixture design and mixture analysis, and describes the design of experiment of the 5-component mixture with the constraint conditions. The mathematic models of 28-day compressive strength varying with the ingredients are fitted, and the main effect and interaction effect of two ingredients are identified quantitatively along with the graphical interpretation using the response trace plot and contour plots

  5. Solvation of hydrocarbons in aqueous-organic mixtures

    International Nuclear Information System (INIS)

    Sedov, I.A.; Magsumov, T.I.; Solomonov, B.N.

    2016-01-01

    Highlights: • Thermodynamic functions of solvation in mixtures of water with acetone and acetonitrile are measured at T = 298.15 K. • Solvation of n-octane and toluene in aqueous-organic mixtures is studied. • When increasing water content, Gibbs free energies grow up steadily, while enthalpies have a maximum. • Hydrocarbons are preferentially solvated with organic cosolvent even in mixtures with rather high water content. • Acetonitrile suppresses the hydrophobic effect less than acetone. - Abstract: We study the solvation of two hydrocarbons, n-octane and toluene, in binary mixtures of water with organic cosolvents. Two polar aprotic cosolvents that are miscible with water in any proportions, acetonitrile and acetone, were considered. We determine the magnitudes of thermodynamic functions of dissolution and solvation at T = 298.15 K in the mixtures with various compositions. Solution calorimetry was used to measure the enthalpies of solution, and GC headspace analysis was applied to obtain limiting activity coefficients of solutes in the studied systems. For the first time, the enthalpies of solution of alkane in the mixtures with high water content were measured directly. We observed well-pronounced maxima of the dependencies of enthalpies of solvation from the composition of solvent and no maxima for the Gibbs free energies of solvation. Two factors are concluded to be important to explain the observed tendencies: high energy cost of reorganization of binary solvent upon insertion of solute molecules and preferential surrounding of hydrocarbons with the molecules of organic cosolvent. Enthalpy-entropy compensation leads to a steady growth of the Gibbs free energies with increasing water content. On the other hand, consideration of the plots of the Gibbs free energy against enthalpy of solvation clearly shows that the solvation properties are changed dramatically after addition of a rather small amount of organic cosolvents. It is shown that they

  6. Toxicity effects of an environmental realistic herbicide mixture on the seagrass Zostera noltei.

    Science.gov (United States)

    Diepens, Noël J; Buffan-Dubau, Evelyne; Budzinski, Hélène; Kallerhoff, Jean; Merlina, Georges; Silvestre, Jérome; Auby, Isabelle; Nathalie Tapie; Elger, Arnaud

    2017-03-01

    Worldwide seagrass declines have been observed due to multiple stressors. One of them is the mixture of pesticides used in intensive agriculture and boat antifouling paints in coastal areas. Effects of mixture toxicity are complex and poorly understood. However, consideration of mixture toxicity is more realistic and ecologically relevant for environmental risk assessment (ERA). The first aim of this study was to determine short-term effects of realistic herbicide mixture exposure on physiological endpoints of Zostera noltei. The second aim was to assess the environmental risks of this mixture, by comparing the results to previously published data. Z. noltei was exposed to a mixture of four herbicides: atrazine, diuron, irgarol and S-metolachlor, simulating the composition of typical cocktail of contaminants in the Arcachon bay (Atlantic coast, France). Three stress biomarkers were measured: enzymatic activity of glutathione reductase, effective quantum yield (EQY) and photosynthetic pigment composition after 6, 24 and 96 h. Short term exposure to realistic herbicide mixtures affected EQY, with almost 100% inhibition for the two highest concentrations, and photosynthetic pigments. Effect on pigment composition was detected after 6 h with a no observed effect concentration (NOEC) of 1 μg/L total mixture concentration. The lowest EQY effect concentration at 10% (EC 10 ) (2 μg/L) and pigment composition NOEC with an assessment factor of 10 were above the maximal field concentrations along the French Atlantic coast, suggesting that there are no potential short term adverse effects of this particular mixture on Z. noltei. However, chronic effects on photosynthesis may lead to reduced energy reserves, which could thus lead to effects at whole plant and population level. Understanding the consequences of chemical mixtures could help to improve ERA and enhance management strategies to prevent further declines of seagrass meadows worldwide. Copyright © 2016

  7. Application Of Electronic Nose And Ion Mobility Spectrometer To Quality Control Of Spice Mixtures

    International Nuclear Information System (INIS)

    Banach, U.; Tiebe, C.; Huebert, Th.

    2009-01-01

    The aim of the paper is to demonstrate the application of electronic nose (e-nose) and ion mobility spectrometry (IMS) to quality control and to find out product adulteration of spice mixtures. Therefore the gaseous head space phase of four different spice mixtures (spices for sausages and saveloy) was differed from original composition and product adulteration. In this set of experiments metal-oxide type e-nose (KAMINA-type) has been used, and characteristic patterns of data corresponding to various complex odors of the four different spice mixtures were generated. Simultaneously an ion mobility spectrometer was coupled also to an emission chamber for the detection of gaseous components of spice mixtures. The two main methods that have been used show a clear discrimination between the original spice mixtures and product adulteration could be distinguished from original spice mixtures.

  8. Thermal mixtures in stochastic mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, F [Rome Univ. (Italy). Ist. di Matematica; Loffredo, M I [Salerno Univ. (Italy). Ist. di Fisica

    1981-01-17

    Stochastic mechanics is extended to systems in thermal equilibrium. The resulting stochastic processes are mixtures of Nelson processes. Their Markov property is investigated in some simple cases. It is found that in order to inforce Markov property the algebra of observable associated to the present must be suitably enlarged.

  9. Ecological Assembly of Chemical Mixtures

    Science.gov (United States)

    Human-environment interactions have a significant role in the formation of chemical mixtures in the environment and by extension in human tissues and fluids. These interactions, which include decisions to purchase and use products containing chemicals as well as behaviors and act...

  10. Optimization and characterization of liposome formulation by mixture design.

    Science.gov (United States)

    Maherani, Behnoush; Arab-tehrany, Elmira; Kheirolomoom, Azadeh; Reshetov, Vadzim; Stebe, Marie José; Linder, Michel

    2012-02-07

    This study presents the application of the mixture design technique to develop an optimal liposome formulation by using the different lipids in type and percentage (DOPC, POPC and DPPC) in liposome composition. Ten lipid mixtures were generated by the simplex-centroid design technique and liposomes were prepared by the extrusion method. Liposomes were characterized with respect to size, phase transition temperature, ζ-potential, lamellarity, fluidity and efficiency in loading calcein. The results were then applied to estimate the coefficients of mixture design model and to find the optimal lipid composition with improved entrapment efficiency, size, transition temperature, fluidity and ζ-potential of liposomes. The response optimization of experiments was the liposome formulation with DOPC: 46%, POPC: 12% and DPPC: 42%. The optimal liposome formulation had an average diameter of 127.5 nm, a phase-transition temperature of 11.43 °C, a ζ-potential of -7.24 mV, fluidity (1/P)(TMA-DPH)((¬)) value of 2.87 and an encapsulation efficiency of 20.24%. The experimental results of characterization of optimal liposome formulation were in good agreement with those predicted by the mixture design technique.

  11. Using mixture experiments to develop cementitious waste forms

    International Nuclear Information System (INIS)

    Spence, R.D.; Anderson, C.M.; Piepel, G.F.

    1993-01-01

    Mixture experiments are presented as a means to develop cementitious waste forms. The steps of a mixture experiment are (1) identifying the waste form ingredients; (2) determining the compositional constraints of these ingredients; (3) determining the extreme vertices, edge midpoints, and face centroids of the constrained multidimensional volume (these points along with some interior points represent the set of possible compositions for testing); (4) picking a subset of these points for the experimental design; (5) measuring the properties of the selected subset; and (6) generating the response surface models. The models provide a means for predicting the properties within the constrained region. This article presents an example of this process for one property: unconfined compressive strength

  12. Qualitative criteria and thresholds for low noise asphalt mixture design

    Science.gov (United States)

    Vaitkus, A.; Andriejauskas, T.; Gražulytė, J.; Šernas, O.; Vorobjovas, V.; Kleizienė, R.

    2018-05-01

    Low noise asphalt pavements are cost efficient and cost effective alternative for road traffic noise mitigation comparing with noise barriers, façade insulation and other known noise mitigation measures. However, design of low noise asphalt mixtures strongly depends on climate and traffic peculiarities of different regions. Severe climate regions face problems related with short durability of low noise asphalt mixtures in terms of considerable negative impact of harsh climate conditions (frost-thaw, large temperature fluctuations, hydrological behaviour, etc.) and traffic (traffic loads, traffic volumes, studded tyres, etc.). Thus there is a need to find balance between mechanical and acoustical durability as well as to ensure adequate pavement skid resistance for road safety purposes. Paper presents analysis of the qualitative criteria and design parameters thresholds of low noise asphalt mixtures. Different asphalt mixture composition materials (grading, aggregate, binder, additives, etc.) and relevant asphalt layer properties (air void content, texture, evenness, degree of compaction, etc.) were investigated and assessed according their suitability for durable and effective low noise pavements. Paper concluded with the overview of requirements, qualitative criteria and thresholds for low noise asphalt mixture design for severe climate regions.

  13. Combustible gas production (methane) and biodegradation of solid and liquid mixtures of meat industry wastes

    Energy Technology Data Exchange (ETDEWEB)

    Marcos, A.; Al-Kassir, A.; Cuadros, F.; Lopez-Rodriguez, F. [School of Engineering, University of Extremadura, Avda. De Elva, s/n, 06071, Badajoz (Spain); Mohamad, A.A. [Department of Mechanical and Manufacturing Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, Alberta (Canada)

    2010-05-15

    This work is devoted to determine the optimal operational conditions on the methane production as well as on the biodegradation obtained from the anaerobic codigestion of solid (fat, intestines, rumen, bowels, whiskers, etc.) and liquid (blood, washing water, manure, etc.) wastes of meat industry, particularly the ones rising from the municipal slaughterhouse of Badajoz (Spain). The experiments were performed using a 2 l capacity discontinuous digester at 38 C. The loading rate were 0.5, 1, 2, 3, and 4.5 g COD for wastewater (washing water and blood; Mixture 1), and 0.5, 1, 2, 3, and 4 g COD for the co-digestion of a mixture of 97% liquid effluent and 3% solid wastes v/v (Mixture 2) which represents the annual mean composition of the waste generated by the slaughterhouse. The maximal biodegradation rates obtained were: Mixture 1, 56.9% for a COD load of 1 g; and Mixture 2, 19.1% for a COD load of 2 g. For both mixtures, the greatest methane production was for the maximum COD load (4.5 g for Mixture 1, and 4 g for Mixture 2), at which values the amounts of methane obtained during and at the end of the co-digestion were practically indistinguishable between the two mixtures. The results will be used to design, construct, and establish the optimal operating conditions of a continuous complete-mixture biodigester. (author)

  14. An approach for assessing human exposures to chemical mixtures in the environment

    International Nuclear Information System (INIS)

    Rice, Glenn; MacDonell, Margaret; Hertzberg, Richard C.; Teuschler, Linda; Picel, Kurt; Butler, Jim; Chang, Young-Soo; Hartmann, Heidi

    2008-01-01

    Humans are exposed daily to multiple chemicals, including incidental exposures to complex chemical mixtures released into the environment and to combinations of chemicals that already co-exist in the environment because of previous releases from various sources. Exposures to chemical mixtures can occur through multiple pathways and across multiple routes. In this paper, we propose an iterative approach for assessing exposures to environmental chemical mixtures; it is similar to single-chemical approaches. Our approach encompasses two elements of the Risk Assessment Paradigm: Problem Formulation and Exposure Assessment. Multiple phases of the assessment occur in each element of the paradigm. During Problem Formulation, analysts identify and characterize the source(s) of the chemical mixture, ensure that dose-response and exposure assessment measures are concordant, and develop a preliminary evaluation of the mixture's fate. During Exposure Assessment, analysts evaluate the fate of the chemicals comprising the mixture using appropriate models and measurement data, characterize the exposure scenario, and estimate human exposure to the mixture. We also describe the utility of grouping the chemicals to be analyzed based on both physical-chemical properties and an understanding of environmental fate. In the article, we also highlight the need for understanding of changes in the mixture composition in the environment due to differential transport, differential degradation, and differential partitioning to other media. The section describes the application of the method to various chemical mixtures, highlighting issues associated with assessing exposures to chemical mixtures in the environment

  15. Determination of heavy water in heavy water - light water mixtures

    International Nuclear Information System (INIS)

    Sanhueza M, A.

    1986-01-01

    A description about experimental methodology to determine isotopic composition of heavy water - light water mixtures is presented. The employed methods are Nuclear Magnetic Resonance Spectroscopy, for measuring heavy water concentrations from 0 to 100% with intervals of 10% approx., and mass Spectrometry, for measuring heavy water concentrations from 0.1 to 1% with intervals of 0.15% approx., by means of an indirect method of Dilution. (Author)

  16. Burner redesign for the reduction of the unburned particulate emission in thermal power stations of Comision Federal de Electricidad; Rediseno de quemadores para la reduccion de la emision de particulas inquemadas en centrales termicas de la Comisionon Federal de Electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Huerta Espino, Mario; Espipnoza Garza, Jesus; Mani Gonzalez, Alejandro; Giles Alarcon, Armando; Pena Garcia, Adriana; Albarran Sanchez, Irma L; Mendez Aranda, Angel [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    In the presence of the increasing demand for reaching higher efficiencies and a smaller production of polluting emissions in combustion systems, studies focused to the optimization of the present designs of burners are required. The Comision Federal de Electricidad (CFE) and the Instituto de Investigaciones Electricas (IIE) have established a project that contemplates the redesign of burners in ten of its units of thermoelectric generation. In this work the redesign of the flame stabilizer or diffuser for the reduction of the unburned particulate emission is explained. The results of the modeling of a burner of rotational flow of steam generators of the CFE are shown, as well as the graphs of the contours of the recirculation zone generated by each diffuser without combustion and a figure of the velocity profile that is generated in front of the diffuser. In agreement with the results obtained in the aerodynamic evaluation of frontal burners of rotational flow, it is possible to established that the characteristics of the recirculation zone, generated by this type of burners, are related to geometric parameters of the diffuser that identify with the number of turns and the pressure drop, where it is necessary to look for designs that improve the conditions of the mixing process and combustion in the burner. [Spanish] Ante la creciente demanda por alcanzar mayores eficiencias y una menor produccion de emisiones contaminantes en sistemas de combustion, se requieren estudios enfocados a la optimizacion de los disenos actuales de quemadores. La Comision Federal de Electricidad (CFE) y el Instituto de Investigaciones Electricas (IIE) han establecido un proyecto que contempla el rediseno de quemadores en diez de sus unidades de generacion termoelectrica. En este trabajo se explica el rediseno del estabilizador de flama o difusor para la reduccion de la emision de particulas inquemadas. Se muestran los resultados de la modelacion de un quemador de flujo rotacional de

  17. Misturas NR/SBR: influência da composição e do modo de preparação sobre propriedades mecânicas e reométricas NR/SBR mixtures: influence of composition and preparation mode on the mechanical and rheological properties

    Directory of Open Access Journals (Sweden)

    Hérlon M. B. Abreu Junior

    2010-01-01

    Full Text Available Aplicações de produtos à base de borracha diversas vezes requerem um conjunto de propriedades as quais, geralmente, não são fornecidas por um único elastômero. Dessa forma, um dos recursos utilizados é a mistura de dois ou mais polímeros para obtenção de novas propriedades. Neste caso, os demais ingredientes que são adicionados, normalmente distribuem-se de forma irregular, dependendo de sua afinidade com cada uma das borrachas. O grau de dispersão de cada um desses ingredientes em cada fase elastomérica irá então influenciar a velocidade de cura e o grau de vulcanização e, certamente, terá conseqüências nas propriedades do produto final. Neste trabalho, a borracha natural (NR foi misturada ao elastômero de butadieno-estireno (SBR nas proporções de 75:25 e 50:50, em massa. As composições foram preparadas empregando-se quatro maneiras distintas para a incorporação dos aditivos. Os resultados das propriedades mecânicas mostraram que, apesar da utilização de uma mesma formulação, o modo de preparo tem grande influência sobre as propriedades. No caso da mistura NR/SBR as melhores propriedades são obtidas quando é favorecida a vulcanização da borracha que, isoladamente, apresenta propriedades inferiores.Frequently a set of properties required for a given application cannot be accomplished by one elastomer only and, thus, mixtures of two or more polymers must be employed. In these cases, the other ingredients added are normally dispersed in a non homogeneous way, depending on their affinity to each polymer. The degree of dispersion each additive experiences in each elastomeric phase will influence the rate and the degree of vulcanization and will certainly have consequences on the properties of the final product. In this work, natural rubber (NR was mixed with styrene-butadiene elastomer (SBR in 75:25 and 50:50 w/w ratios. The compositions were prepared in a two-roll mill, by introducing the additives according to

  18. Construction of Lines of Constant Density and Constant Refractive Index for Ternary Liquid Mixtures.

    Science.gov (United States)

    Tasic, Aleksandar Z.; Djordjevic, Bojan D.

    1983-01-01

    Demonstrates construction of density constant and refractive index constant lines in triangular coordinate system on basis of systematic experimental determinations of density and refractive index for both homogeneous (single-phase) ternary liquid mixtures (of known composition) and the corresponding binary compositions. Background information,…

  19. Solution enthalpy of potassium iodide in furfural and its mixtures with dimethylsulfoxide

    International Nuclear Information System (INIS)

    Vlasenko, K.K.; Belov, A.A.; Vorob'ev, A.F.

    1986-01-01

    Solution enthalpy of potassium iodide in furfural-dimethylsulfoxide mixtures at 298.15 K and furfural concentration 17.3-100% are determined experimentally. K + and I - ion solvate shell composition, which in the general case doesn't correspond to the mixed solvent composition, is calculated

  20. Composition and Temperature Dependence of Shear Viscosity of Hydrocarbon Mixtures

    Science.gov (United States)

    1980-07-01

    HNN- XTHDCPD Binary System IX. VTF Eq. Parameters for Shear Viscosities Using Constant B Parameter X. Results of Fits to Master Viscosity Eqs. (43...T(K) for 5 C10 Hydrocarbons I Fig. 2a. log n versus 103/T(K) for HNNi I Fig. 2b. log n versus 103/T(K) for XTHDCPD Fig. 3. Isothem of log n versus X...CD for CO-MO Binary System Fig. 4. Isotherm of log n versus XNBC for NBC-DMO Binary System ( ~Fig. 5. Isotherm of log n versus XfINN for HNN- XTHDCPD

  1. Soil mixture composition alters Arabidopsis susceptibility to Pseudomonas syringae infection

    Science.gov (United States)

    Pseudomonas syringae is a Gram-negative bacterial pathogen that causes disease on more than 100 different plant species, including the model plant Arabidopsis thaliana. Dissection of the Arabidopsis thaliana-Pseudomonas syringae pathosystem has identified many factors that contribute to successful ...

  2. Composite materials formed with anchored nanostructures

    Science.gov (United States)

    Seals, Roland D; Menchhofer, Paul A; Howe, Jane Y; Wang, Wei

    2015-03-10

    A method of forming nano-structure composite materials that have a binder material and a nanostructure fiber material is described. A precursor material may be formed using a mixture of at least one metal powder and anchored nanostructure materials. The metal powder mixture may be (a) Ni powder and (b) NiAl powder. The anchored nanostructure materials may comprise (i) NiAl powder as a support material and (ii) carbon nanotubes attached to nanoparticles adjacent to a surface of the support material. The process of forming nano-structure composite materials typically involves sintering the mixture under vacuum in a die. When Ni and NiAl are used in the metal powder mixture Ni.sub.3Al may form as the binder material after sintering. The mixture is sintered until it consolidates to form the nano-structure composite material.

  3. Mixtures in nonstable Levy processes

    International Nuclear Information System (INIS)

    Petroni, N Cufaro

    2007-01-01

    We analyse the Levy processes produced by means of two interconnected classes of nonstable, infinitely divisible distribution: the variance gamma and the Student laws. While the variance gamma family is closed under convolution, the Student one is not: this makes its time evolution more complicated. We prove that-at least for one particular type of Student processes suggested by recent empirical results, and for integral times-the distribution of the process is a mixture of other types of Student distributions, randomized by means of a new probability distribution. The mixture is such that along the time the asymptotic behaviour of the probability density functions always coincide with that of the generating Student law. We put forward the conjecture that this can be a general feature of the Student processes. We finally analyse the Ornstein-Uhlenbeck process driven by our Levy noises and show a few simulations of it

  4. Separation of compounds differing in isotopic composition

    International Nuclear Information System (INIS)

    Sievers, R.E.; Brooks, J.J.

    1976-01-01

    Compounds differing in isotopic composition are separated by introducing a mixture of the compounds into a chromatographic column containing a lanthanide chelate as a stationary phase and eluting from the column a fraction which is at least enriched with one of the compounds of the mixture. 17 claims, no drawings

  5. Separation of compounds differing in isotopic composition

    International Nuclear Information System (INIS)

    Sievers, R.E.; Brooks, J.J.

    1975-01-01

    Compounds differing in isotopic composition are separated by introducing a mixture of the compounds into a chromatographic column containing a lanthanide chelate as a stationary phase and eluting from the column a fraction that is at least enriched with one of the compounds of the mixture. (U.S.)

  6. Consistency of the MLE under mixture models

    OpenAIRE

    Chen, Jiahua

    2016-01-01

    The large-sample properties of likelihood-based statistical inference under mixture models have received much attention from statisticians. Although the consistency of the nonparametric MLE is regarded as a standard conclusion, many researchers ignore the precise conditions required on the mixture model. An incorrect claim of consistency can lead to false conclusions even if the mixture model under investigation seems well behaved. Under a finite normal mixture model, for instance, the consis...

  7. Dirichlet Process Parsimonious Mixtures for clustering

    OpenAIRE

    Chamroukhi, Faicel; Bartcus, Marius; Glotin, Hervé

    2015-01-01

    The parsimonious Gaussian mixture models, which exploit an eigenvalue decomposition of the group covariance matrices of the Gaussian mixture, have shown their success in particular in cluster analysis. Their estimation is in general performed by maximum likelihood estimation and has also been considered from a parametric Bayesian prospective. We propose new Dirichlet Process Parsimonious mixtures (DPPM) which represent a Bayesian nonparametric formulation of these parsimonious Gaussian mixtur...

  8. An Efficient Composition for Bengal Lights.

    Science.gov (United States)

    Comet, M.; Schreyeck, L.; Fuzellier, H.

    2002-01-01

    Reports the discovery of an efficient base composition for making bengal lights that is obtained with potassium chlorate and thiourea. Combining this mixture with appropriate flame coloring can produce several impressive bengal lights. (DDR)

  9. Dynamic mean field theory for lattice gas models of fluid mixtures confined in mesoporous materials.

    Science.gov (United States)

    Edison, J R; Monson, P A

    2013-11-12

    We present the extension of dynamic mean field theory (DMFT) for fluids in porous materials (Monson, P. A. J. Chem. Phys. 2008, 128, 084701) to the case of mixtures. The theory can be used to describe the relaxation processes in the approach to equilibrium or metastable equilibrium states for fluids in pores after a change in the bulk pressure or composition. It is especially useful for studying systems where there are capillary condensation or evaporation transitions. Nucleation processes associated with these transitions are emergent features of the theory and can be visualized via the time dependence of the density distribution and composition distribution in the system. For mixtures an important component of the dynamics is relaxation of the composition distribution in the system, especially in the neighborhood of vapor-liquid interfaces. We consider two different types of mixtures, modeling hydrocarbon adsorption in carbon-like slit pores. We first present results on bulk phase equilibria of the mixtures and then the equilibrium (stable/metastable) behavior of these mixtures in a finite slit pore and an inkbottle pore. We then use DMFT to describe the evolution of the density and composition in the pore in the approach to equilibrium after changing the state of the bulk fluid via composition or pressure changes.

  10. A role of low dose chemical mixtures in adipose tissue in carcinogenesis.

    Science.gov (United States)

    Lee, Duk-Hee; Jacobs, David R; Park, Ho Yong; Carpenter, David O

    2017-11-01

    The Halifax project recently hypothesized a composite carcinogenic potential of the mixture of low dose chemicals which are commonly encountered environmentally, yet which are not classified as human carcinogens. A long neglected but important fact is that adipose tissue is an important exposure source for chemical mixtures. In fact, findings from human studies based on several persistent organic pollutants in general populations with only background exposure should be interpreted from the viewpoint of chemical mixtures because serum concentrations of these chemicals can be seen as surrogates for chemical mixtures in adipose tissue. Furthermore, in conditions such as obesity with dysfunctional adipocytes or weight loss in which lipolysis is increased, the amount of the chemical mixture released from adipose tissue to circulation is increased. Thus, both obesity and weight loss can enhance the chance of chemical mixtures reaching critical organs, however paradoxical this idea may be when fat mass is the only factor considered. The complicated, interrelated dynamics of adipocytes and chemical mixtures can explain puzzling findings related to body weight among cancer patients, including the obesity paradox. The contamination of fat in human diet with chemical mixtures, occurring for reasons similar to contamination of human adipose tissue, may be a missing factor which affects the association between dietary fat intake and cancer. The presence of chemical mixtures in adipose tissue should be considered in future cancer research, including clinical trials on weight management among cancer survivors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Some properties of explosive mixtures containing peroxides

    International Nuclear Information System (INIS)

    Zeman, Svatopluk; Trzcinski, Waldemar A.; Matyas, Robert

    2008-01-01

    This study concerns mixtures of triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP) and ammonium nitrate (AN) with added water (W), as the case may be, and dry mixtures of TATP with urea nitrate (UN). Relative performances (RP) of the mixtures and their individual components, relative to TNT, were determined by means of ballistic mortar. The detonation energies, E 0 , and detonation velocities, D, were calculated for the mixtures studied by means of the thermodynamic code CHEETAH. Relationships have been found and are discussed between the RP and the E 0 values related to unit volume of gaseous products of detonation of these mixtures. These relationships together with those between RP and oxygen balance values of the mixtures studied indicate different types of participation of AN and UN in the explosive decomposition of the respective mixtures. Dry TATP/UN mixtures exhibit lower RP than analogous mixtures TATP/AN containing up to 25% of water. Depending on the water content, the TATP/AN mixtures possess higher detonability values than the ANFO explosives. A semi-logarithmic relationship between the D values and oxygen coefficients has been derived for all the mixtures studied at the charge density of 1000 kg m -3 . Among the mixtures studied, this relationship distinguishes several samples of the type of 'tertiary explosives' as well as samples that approach 'high explosives' in their performances and detonation velocities

  12. Base-line data on everglades soil-plant systems: elemental composition, biomass, and soil depth

    International Nuclear Information System (INIS)

    Volk, B.G.; Schemnitz, S.D.; Gamble, J.F.; Sartain, J.B.

    1975-01-01

    Plants and soils from plots in the Everglades Wildlife Management Area, Conservation Area 3, were examined. Chemical composition (N, P, K, Ca, Mg, Na, Cu, Fe, Mn, Zn, Co, Sr, Pb, Ni, Cr, Al, and Si) of most plant and soil digests was determined. Cladium jamaicense was the predominant plant species contributing to biomass in all plots except the wet prairie, where Rhynchospora sp. and Panicum hemitomon were most common. The biomass of dead C. jamaicense was greater than that of the living plants in unburned saw-grass plots. The burned saw grass, muck burn, and wet prairie were characterized by a large number of plant species per square meter but smaller average biomass production than the unburned saw-grass locations. Levels of Cu, Mn, Ca, Mg, K, and N in C. jamaicense differed significantly across locations. Highly significant differences in elemental composition existed between plant species. Concentrations of several elements (particularly Zn, Ca, Mg, P, and N) were low in live C. jamaicense compared with other plant species. Cesium-137 levels ranged from 670 to 3100 pCi/kg in sandy and in organic soils, respectively. Polygonum had a 137 Cs level of 11,600 pCi/kg. Dead C. jamaicense indicated a rapid leaching loss of 137 Cs from dead tissue

  13. Thermodynamic studies of mixtures for topical anesthesia: Lidocaine-salol binary phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Lazerges, Mathieu [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France); Rietveld, Ivo B., E-mail: ivo.rietveld@parisdescartes.fr [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France); Corvis, Yohann; Ceolin, Rene; Espeau, Philippe [Laboratoire de Chimie Physique (EA 4066), Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75270 Paris Cedex 06 (France)

    2010-01-10

    The lidocaine-salol binary system has been investigated by differential scanning calorimetry, direct visual observations, and X-ray powder diffraction, resulting in a temperature-composition phase diagram with a eutectic equilibrium. The eutectic mixture, found at 0.423 {+-} 0.007 lidocaine mole-fraction, melts at 18.2 {+-} 0.5 {sup o}C with an enthalpy of 17.3 {+-} 0.5 kJ mol{sup -1}. This indicates that the liquid phase around the eutectic composition is stable at room temperature. Moreover, the undercooled liquid mixture does not easily crystallize. The present binary mixture exhibits eutectic behavior similar to the prilocaine-lidocaine mixture in the widely used EMLA topical anesthetic preparation.

  14. Plasmachemical synthesis of nanopowders of yttria and zirconia from dispersed water-salt-organic mixtures

    Science.gov (United States)

    Novoselov, Ivan; Karengin, Alexander; Shamanin, Igor; Alyukov, Evgeny; Gusev, Alexander

    2018-03-01

    Article represents results on theoretical and experimental research of yttria and zirconia plasmachemical synthesis in air plasma from water-salt-organic mixtures "yttrium nitrate-water-acetone" and "zirconyl nitrate-water-acetone". On the basis of thermotechnical calculations the influence of organic component on lower heat value and adiabatic combustion temperature of water-salt-organic mixtures as well as compositions of mixtures providing their energy-efficient plasma treatment were determined. The calculations found the influence of mass fraction and temperature of air plasma supporting gas on the composition of plasma treatment products. It was determined the conditions providing yttria and zirconia plasmachemical synthesis in air plasma. During experiments it was b eing carried out the plasmachemical synthesis of yttria and zirconia powders in air plasma flow from water -salt-organic mixtures. Analysis of the results for obtained powders (scanning electron microscopy, X-ray diffraction analysis, BET analysis) confirm nanostructure of yttria and zirconia.

  15. Thermodynamic studies of mixtures for topical anesthesia: Lidocaine-salol binary phase diagram

    International Nuclear Information System (INIS)

    Lazerges, Mathieu; Rietveld, Ivo B.; Corvis, Yohann; Ceolin, Rene; Espeau, Philippe

    2010-01-01

    The lidocaine-salol binary system has been investigated by differential scanning calorimetry, direct visual observations, and X-ray powder diffraction, resulting in a temperature-composition phase diagram with a eutectic equilibrium. The eutectic mixture, found at 0.423 ± 0.007 lidocaine mole-fraction, melts at 18.2 ± 0.5 o C with an enthalpy of 17.3 ± 0.5 kJ mol -1 . This indicates that the liquid phase around the eutectic composition is stable at room temperature. Moreover, the undercooled liquid mixture does not easily crystallize. The present binary mixture exhibits eutectic behavior similar to the prilocaine-lidocaine mixture in the widely used EMLA topical anesthetic preparation.

  16. The composition of interstellar grain mantles

    International Nuclear Information System (INIS)

    Tielens, A.G.G.M.

    1984-01-01

    The molecular composition of interstellar grain mantles employing gas phase as well as grain surface reactions has been calculated. The calculated mixtures consist mainly of the molecules H 2 O H 2 CO, N 2 , CO, O 2 , CO 2 , H 2 O 2 , NH 3 , and their deuterated counterparts in varying ratios. The exact compositions depend strongly on the physical conditions in the gas phase. The calculated mixtures are compared to the observations by using laboratory spectra of grain mantle analogs. (author)

  17. Stability studies of colloidal silica dispersions in binary solvent mixtures

    International Nuclear Information System (INIS)

    Bean, Keith Howard

    1997-01-01

    A series of monodispersed colloidal silica dispersions, of varying radii, has been prepared. These particles are hydrophilic in nature due to the presence of surface silanol groups. Some of the particles have been rendered hydrophobic by terminally grafting n-alkyl (C 18 ) chains to the surface. The stability of dispersions of these various particles has been studied in binary mixtures of liquids, namely (i) ethanol and cyclohexane, and (ii) benzene and n-heptane. The ethanol - cyclohexane systems have been studied using a variety of techniques. Adsorption excess isotherms have been established and electrophoretic mobility measurements have been made. The predicted stability of the dispersions from D.V.L.O. calculations is compared to the observed stability. The hydrophilic silica particles behave as predicted by the calculations, with the zeta potential decreasing and the van der Waals attraction increasing with increasing cyclohexane concentration. The hydrophobic particles behave differently than expected, and the stability as a function of solvent mixture composition does not show a uniform trend. The effect of varying the coverage of C 18 chains on the surface and the effect of trace water in the systems has also been investigated. Organophilic silica dispersions in benzene - n-heptane solvent mixtures show weak aggregation and phase separation into a diffuse 'gas-like' phase and a more concentrated 'liquid-like' phase, analogous to molecular condensation processes. Calculations of the van der Waals potential as a function of solvent mixture composition show good agreement with the observed stability. Determination of the number of particles in each phase at equilibrium allows the energy of flocculation to be determined using a simple thermodynamic relationship. Finally, the addition of an AB block copolymer to organophilic silica particles in benzene n-heptane solvent mixtures has been shown to have a marked effect on the dispersion stability. This stability

  18. Mixture-mixture design for the fingerprint optimization of chromatographic mobile phases and extraction solutions for Camellia sinensis.

    Science.gov (United States)

    Borges, Cleber N; Bruns, Roy E; Almeida, Aline A; Scarminio, Ieda S

    2007-07-09

    A composite simplex centroid-simplex centroid mixture design is proposed for simultaneously optimizing two mixture systems. The complementary model is formed by multiplying special cubic models for the two systems. The design was applied to the simultaneous optimization of both mobile phase chromatographic mixtures and extraction mixtures for the Camellia sinensis Chinese tea plant. The extraction mixtures investigated contained varying proportions of ethyl acetate, ethanol and dichloromethane while the mobile phase was made up of varying proportions of methanol, acetonitrile and a methanol-acetonitrile-water (MAW) 15%:15%:70% mixture. The experiments were block randomized corresponding to a split-plot error structure to minimize laboratory work and reduce environmental impact. Coefficients of an initial saturated model were obtained using Scheffe-type equations. A cumulative probability graph was used to determine an approximate reduced model. The split-plot error structure was then introduced into the reduced model by applying generalized least square equations with variance components calculated using the restricted maximum likelihood approach. A model was developed to calculate the number of peaks observed with the chromatographic detector at 210 nm. A 20-term model contained essentially all the statistical information of the initial model and had a root mean square calibration error of 1.38. The model was used to predict the number of peaks eluted in chromatograms obtained from extraction solutions that correspond to axial points of the simplex centroid design. The significant model coefficients are interpreted in terms of interacting linear, quadratic and cubic effects of the mobile phase and extraction solution components.

  19. TRANSPORT PROPERTIES FOR REFRIGERANT MIXTURES

    Directory of Open Access Journals (Sweden)

    V. Geller

    2014-06-01

    Full Text Available A set of models to predict viscosity and thermal conductivity of refrigerant mixtures is developed. A general model for viscosity and thermal conductivity use the three contributions sum form (the dilute-gas terms, the residual terms, and the liquid terms. The corresponding states model is recommended to predict the dense gas transport properties over a range of reduced density from 0 to 2. It is shown that the RHS model provides the most reliable results for the saturated-liquid and the compressed-liquid transport properties over a range of given temperatures from 0,5 to 0,95.

  20. Nonparametric Mixture of Regression Models.

    Science.gov (United States)

    Huang, Mian; Li, Runze; Wang, Shaoli

    2013-07-01

    Motivated by an analysis of US house price index data, we propose nonparametric finite mixture of regression models. We study the identifiability issue of the proposed models, and develop an estimation procedure by employing kernel regression. We further systematically study the sampling properties of the proposed estimators, and establish their asymptotic normality. A modified EM algorithm is proposed to carry out the estimation procedure. We show that our algorithm preserves the ascent property of the EM algorithm in an asymptotic sense. Monte Carlo simulations are conducted to examine the finite sample performance of the proposed estimation procedure. An empirical analysis of the US house price index data is illustrated for the proposed methodology.

  1. Prenatal exposure to an environmentally relevant phthalate mixture disrupts reproduction in F1 female mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Changqing; Gao, Liying; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2017-03-01

    Phthalates are used in a large variety of products, such as building materials, medical devices, and personal care products. Most previous studies on the toxicity of phthalates have focused on single phthalates, but it is also important to study the effects of phthalate mixtures because humans are exposed to phthalate mixtures. Thus, we tested the hypothesis that prenatal exposure to an environmentally relevant phthalate mixture adversely affects female reproduction in mice. To test this hypothesis, pregnant CD-1 dams were orally dosed with vehicle (tocopherol-stripped corn oil) or a phthalate mixture (20 and 200 μg/kg/day, 200 and 500 mg/kg/day) daily from gestational day 10 to birth. The mixture was based on the composition of phthalates detected in urine samples from pregnant women in Illinois. The mixture included 35% diethyl phthalate, 21% di(2-ethylhexyl) phthalate, 15% dibutyl phthalate, 15% diisononyl phthalate, 8% diisobutyl phthalate, and 5% benzylbutyl phthalate. Female mice born to the exposed dams were subjected to tissue collections and fertility tests at different ages. Our results indicate that prenatal exposure to the phthalate mixture significantly increased uterine weight and decreased anogenital distance on postnatal days 8 and 60, induced cystic ovaries at 13 months, disrupted estrous cyclicity, reduced fertility-related indices, and caused some breeding complications at 3, 6, and 9 months of age. Collectively, our data suggest that prenatal exposure to an environmentally relevant phthalate mixture disrupts aspects of female reproduction in mice. - Highlights: • Prenatal exposure to a phthalate mixture disrupts F1 estrous cyclicity. • Prenatal exposure to a phthalate mixture induces F1 ovarian cysts. • Prenatal exposure to a phthalate mixture decreases F1 female fertility-related indices. • Prenatal exposure to a phthalate mixture induces F1 breeding complications.

  2. Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture.

    Science.gov (United States)

    Yang, Chao; Xie, Jun; Zhou, Xiaojun; Liu, Quantao; Pang, Ling

    2018-04-27

    Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diatomite were investigated. The characterization of diatomite exhibits that it is a porous material with high SiO₂ content and large specific surface area. It contributes to asphalt absorption and therefore leads to bonding enhancement between asphalt and aggregate. However, physical absorption instead of chemical reaction occurs according to the results of FTIR. The resistance of asphalt mixtures with diatomite to permanent deformation and moisture are superior to those of the control mixtures. But, the addition of diatomite does not help to improve the crack and fatigue resistance of asphalt mixture.

  3. Performance Characteristic of Cold Recycled Mixture with Asphalt Emulsion and Chemical Additives

    Directory of Open Access Journals (Sweden)

    Shaowen Du

    2015-01-01

    Full Text Available Three types of chemical additives were used to modify asphalt emulsion recycled mixture. These chemical additives include composite Portland cement (CPC, hydrated lime (HL, and a combination of hydrated lime and ground-granulated blast-furnace slag (GGBF. The influence of different additives on the recycled mixture performance was investigated by volumetric and strength tests, moisture susceptibility test, rutting resistance test, and low temperature bending test. To better understand its performance characteristic, the microstructure images of the recycled mixture were observed by environmental scanning electron microscope (ESEM. Test results demonstrate that the performance improvement of the emulsion recycled mixture depends on the types and content of chemical additives. Several recommendations are presented for the selection of chemical materials. Based on ESEM image analysis, the interface bonding mechanism is proposed to explain the performance characteristic of the recycled mixture with asphalt emulsion and cementitious materials.

  4. Performance Evaluation and Improving Mechanisms of Diatomite-Modified Asphalt Mixture

    OpenAIRE

    Chao Yang; Jun Xie; Xiaojun Zhou; Quantao Liu; Ling Pang

    2018-01-01

    Diatomite is an inorganic natural resource in large reserve. This study consists of two phases to evaluate the effects of diatomite on asphalt mixtures. In the first phase, we characterized the diatomite in terms of mineralogical properties, chemical compositions, particle size distribution, mesoporous distribution, morphology, and IR spectra. In the second phase, road performances, referring to the permanent deformation, crack, fatigue, and moisture resistance, of asphalt mixtures with diato...

  5. Passive dosing of polycyclic aromatic hydrocarbon (PAH) mixtures to terrestrial springtails: linking mixture toxicity to chemical activities, equilibrium lipid concentrations, and toxic units.

    Science.gov (United States)

    Schmidt, Stine N; Holmstrup, Martin; Smith, Kilian E C; Mayer, Philipp

    2013-07-02

    A 7-day mixture toxicity experiment with the terrestrial springtail Folsomia candida was conducted, and the effects were linked to three different mixture exposure parameters. Passive dosing from silicone was applied to tightly control exposure levels and compositions of 12 mixture treatments, containing the polycyclic aromatic hydrocarbons (PAHs) naphthalene, phenanthrene, and pyrene. Springtail lethality was then linked to sum chemical activities (∑a), sum equilibrium lipid concentrations (∑C(lipid eq.)), and sum toxic units (∑TU). In each case, the effects of all 12 mixture treatments could be fitted to one sigmoidal exposure-response relationship. The effective lethal chemical activity (La50) of 0.027 was well within the expected range for baseline toxicity of 0.01-0.1. Linking the effects to the lipid-based exposure parameter yielded an effective lethal concentration (LC(lipid eq 50)) of 133 mmol kg(-1) lipid in good correspondence with the lethal membrane burden for baseline toxicity (40-160 mmol kg(-1) lipid). Finally, the effective lethal toxic unit (LTU50) of 1.20 was rather close to the expected value of 1. Altogether, passive dosing provided tightly controlled mixture exposure in terms of both level and composition, while ∑a, ∑C(lipid eq.), and ∑TU allowed baseline toxicity to be linked to mixture exposure.

  6. GRAVITY PIPELINE TRANSPORT FOR HARDENING FILLING MIXTURES

    Directory of Open Access Journals (Sweden)

    Leonid KROUPNIK

    2015-12-01

    Full Text Available In underground mining of solid minerals becoming increasingly common development system with stowing hardening mixtures. In this case the natural ore array after it is replaced by an artificial excavation of solidified filling mixture consisting of binder, aggregates and water. Such a mixture is prepared on the surface on special stowing complexes and transported underground at special stowing pipelines. However, it is transported to the horizons of a few kilometers, which requires a sustainable mode of motion of such a mixture in the pipeline. Hardening stowing mixture changes its rheological characteristics over time, which complicates the calculation of the parameters of pipeline transportation. The article suggests a method of determining the initial parameters of such mixtures: the status coefficient, indicator of transportability, coefficient of hydrodynamic resistance to motion of the mixture. These indicators characterize the mixture in terms of the possibility to transport it through pipes. On the basis of these indicators is proposed methodology for calculating the parameters of pipeline transport hardening filling mixtures in drift mode when traffic on the horizontal part of the mixture under pressure column of the mixture in the vertical part of the backfill of the pipeline. This technique allows stable operation is guaranteed to provide pipeline transportation.

  7. Vibrational relaxation in OCS mixtures

    International Nuclear Information System (INIS)

    Simpson, C.J.S.M.; Gait, P.D.; Simmie, J.M.

    1976-01-01

    Experimental measurements are reported of vibrational relaxation times which may be used to show whether there is near resonant vibration-rotation energy transfer between OCS and H 2 , D 2 or HD. Vibrational relaxation times have been measured in OCS and OCS mixtures over the temperature range 360 to 1000 K using a shock tube and a laser schlieren system. The effectiveness of the additives in reducing the relaxation time of OCS is in the order 4 He 3 He 2 2 and HD. Along this series the effect of an increase in temperature changes from the case of speeding up the rate with 4 He to retarding it with D 2 , HD and H 2 . There is no measurable difference in the effectiveness of n-D 2 and o-D 2 and little, or no, difference between n-H 2 and p-H 2 . Thus the experimental results do not give clear evidence for rotational-vibration energy transfer between hydrogen and OCS. This contrasts with the situation for CO 2 + H 2 mixtures. (author)

  8. Supercritical Water Mixture (SCWM) Experiment

    Science.gov (United States)

    Hicks, Michael C.; Hegde, Uday G.

    2012-01-01

    The subject presentation, entitled, Supercritical Water Mixture (SCWM) Experiment, was presented at the International Space Station (ISS) Increment 33/34 Science Symposium. This presentation provides an overview of an international collaboration between NASA and CNES to study the behavior of a dilute aqueous solution of Na2SO4 (5% w) at near-critical conditions. The Supercritical Water Mixture (SCWM) investigation, serves as important precursor work for subsequent Supercritical Water Oxidation (SCWO) experiments. The SCWM investigation will be performed in DECLICs High Temperature Insert (HTI) for the purpose of studying critical fluid phenomena at high temperatures and pressures. The HTI includes a completely sealed and integrated test cell (i.e., Sample Cell Unit SCU) that will contain approximately 0.3 ml of the aqueous test solution. During the sequence of tests, scheduled to be performed in FY13, temperatures and pressures will be elevated to critical conditions (i.e., Tc = 374C and Pc = 22 MPa) in order to observe salt precipitation, precipitate agglomeration and precipitate transport in the presence of a temperature gradient without the influences of gravitational forces. This presentation provides an overview of the motivation for this work, a description of the DECLIC HTI hardware, the proposed test sequences, and a brief discussion of the scientific research objectives.

  9. Free radical explosive composition

    Science.gov (United States)

    Walker, Franklin E.; Wasley, Richard J.

    1979-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a getter additive comprising a compound or mixture of compounds capable of capturing or deactivating free radicals or ions under mechanical or electrical shock conditions and which is not an explosive. Exemplary getter additives are isocyanates, olefins and iodine.

  10. Scattering and radiative properties of semi-external versus external mixtures of different aerosol types

    International Nuclear Information System (INIS)

    Mishchenko, Michael I.; Liu Li; Travis, Larry D.; Lacis, Andrew A.

    2004-01-01

    The superposition T-matrix method is used to compute the scattering of unpolarized light by semi-external aerosol mixtures in the form of polydisperse, randomly oriented two-particle clusters with touching components. The results are compared with those for composition-equivalent external aerosol mixtures, in which the components are widely separated and scatter light in isolation from each other. It is concluded that aggregation is likely to have a relatively weak effect on scattering and radiative properties of two-component tropospheric aerosols and can be replaced by the much simpler external-mixture model in remote sensing studies and atmospheric radiation balance computations

  11. Hofmeister effect of salt mixtures on thermo-responsive poly(propylene oxide)

    DEFF Research Database (Denmark)

    Moghaddam, Saeed Zajforoushan; Thormann, Esben

    2015-01-01

    of aqueous solutions of poly(propylene oxide) is affected by mixtures of ions with different location in the Hofmeister series. Our results show that the Hofmeister effects of pure salt species are not always linearly additive and that the relative effect of some ions can be reversed depending...... on the composition of the salt mixture as well as by the absolute and relative concentration of the different species. We suggest that these results can lead to a better understanding of the potential role of the Hofmeister effect in regulation of biological processes, which does always take place in salt mixtures...... rather than solutions containing just single salt species....

  12. Change of hydrogen bonding structure in ionic liquid mixtures by anion type

    Science.gov (United States)

    Cha, Seoncheol; Kim, Doseok

    2018-05-01

    Ionic liquid mixtures have gained attention as a way of tuning material properties continuously with composition changes. For some mixture systems, physicochemical properties such as excess molar volume have been found to be significantly different from the value expected by linear interpolation, but the origin of this deviation is not well understood yet. The microstructure of the mixture, which can range from an ideal mixture of two initial consisting ionic liquids to a different structure from those of pure materials, has been suggested as the origin of the observed deviation. The structures of several different ionic liquid mixtures are studied by IR spectroscopy to confirm this suggestion, as a particular IR absorption band (νC(2)-D) for the moiety participating in the hydrogen bonding changes sensitively with the change of the anion in the ionic liquid. The absorbance of νC(2)-D changes proportionally with the composition, and a relatively small excess molar volume is observed for the mixtures containing an electronegative halide anion. By contrast, the absorbance changes nonlinearly, and the excess molar volumes are larger for the mixtures of which one of the anions has multiple interaction sites.

  13. Study of the refractive index of gasoline+alcohol pseudo-binary mixtures

    Directory of Open Access Journals (Sweden)

    Nita Irina

    2017-02-01

    Full Text Available The properties of gasoline change as a result of blending with a bioalcohol, affecting the behavior of the pseudo-binary system. The aim of this paper is to present experimental data of the refractive index for pseudobinary mixtures of a reformate gasoline with ethanol, isopropanol and n-butanol over the entire composition range and for temperature ranging from 293.15 K to 313.15 K. The accuracy of different equations to predict the refractive index of the mixtures was tested. The best prediction accuracy (the lower AAD corresponded to Eykman and Lorentz-Lorenz mixing rules. A logarithmic equation proposed to correlate the refractive index with composition and temperature of gasoline+alcohol mixtures showed a good accuracy (the absolute average deviation AAD < 0.052%. The deviations in refractive index for investigated systems are negative over the entire composition range and at all investigated temperatures.

  14. POTENTIAL MODIFICATION OF HYDRATION OF ALKALI ACTIVATED MIXTURES FROM GRANULATED BLAST FURNACE SLAG AND FLY ASH

    Directory of Open Access Journals (Sweden)

    VÁCLAVA TOMKOVÁ

    2012-07-01

    Full Text Available Alkali activated binders (AAB and composites from suitable latent hydraulic raw materials represent an alternative to materials based on Portland cements. The paper deals with possibilities to influence functional parameters of AAB by setting the mixtures of GBFS and fly ash to the selected chemical composition or by fly ash reactivity change effected by milling. In this way course of hydration process is modified, the alkali activation products phase composition is changed as well as their final characteristic. The amorphous character of the hydration products limits the evaluation of the composition during the massing phase. Part of the study is the search for possibilities of identifying the differences in composition and properties of specially drafted mixtures of original raw materials after their alkali activation.

  15. Partially composite Higgs models

    DEFF Research Database (Denmark)

    Alanne, Tommi; Buarque Franzosi, Diogo; Frandsen, Mads T.

    2018-01-01

    We study the phenomenology of partially composite-Higgs models where electroweak symmetry breaking is dynamically induced, and the Higgs is a mixture of a composite and an elementary state. The models considered have explicit realizations in terms of gauge-Yukawa theories with new strongly...... interacting fermions coupled to elementary scalars and allow for a very SM-like Higgs state. We study constraints on their parameter spaces from vacuum stability and perturbativity as well as from LHC results and find that requiring vacuum stability up to the compositeness scale already imposes relevant...... constraints. A small part of parameter space around the classically conformal limit is stable up to the Planck scale. This is however already strongly disfavored by LHC results. in different limits, the models realize both (partially) composite-Higgs and (bosonic) technicolor models and a dynamical extension...

  16. PURIFICATION AND ENRICHMENT OF BIOGAS IN ASH-WATER MIXTURE

    Directory of Open Access Journals (Sweden)

    Andrzej Brudniak

    2014-10-01

    Full Text Available Biogas, produced in an aerobic digestion process, is a mixture of gases, and that is why its inexpensive and effective valorisation is essential. Research on this process is necessary in order to use biogas as a renewable energy source. The aim of this thesis is to present methods of biogas purification and enrichment in the fly ash - water mixture, that is generated on the base of fly ash produced during burning coal in power industry. Experience presented that the fly ash absorbs CO2 and H2S, even in conventional conditions. The absorption efficiency depends not only on the chemical composition of the ash but also on its physical properties. There was also a strong neutralization of alkaline waste combustion.

  17. Method of producing exfoliated graphite composite compositions for fuel cell flow field plates

    Energy Technology Data Exchange (ETDEWEB)

    Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

    2014-04-08

    A method of producing an electrically conductive composite composition, which is particularly useful for fuel cell bipolar plate applications. The method comprises: (a) providing a supply of expandable graphite powder; (b) providing a supply of a non-expandable powder component comprising a binder or matrix material; (c) blending the expandable graphite with the non-expandable powder component to form a powder mixture wherein the non-expandable powder component is in the amount of between 3% and 60% by weight based on the total weight of the powder mixture; (d) exposing the powder mixture to a temperature sufficient for exfoliating the expandable graphite to obtain a compressible mixture comprising expanded graphite worms and the non-expandable component; (e) compressing the compressible mixture at a pressure within the range of from about 5 psi to about 50,000 psi in predetermined directions into predetermined forms of cohered graphite composite compact; and (f) treating the so-formed cohered graphite composite to activate the binder or matrix material thereby promoting adhesion within the compact to produce the desired composite composition. Preferably, the non-expandable powder component further comprises an isotropy-promoting agent such as non-expandable graphite particles. Further preferably, step (e) comprises compressing the mixture in at least two directions. The method leads to composite plates with exceptionally high thickness-direction electrical conductivity.

  18. Quality improvement of melt extruded laminar systems using mixture design.

    Science.gov (United States)

    Hasa, D; Perissutti, B; Campisi, B; Grassi, M; Grabnar, I; Golob, S; Mian, M; Voinovich, D

    2015-07-30

    This study investigates the application of melt extrusion for the development of an oral retard formulation with a precise drug release over time. Since adjusting the formulation appears to be of the utmost importance in achieving the desired drug release patterns, different formulations of laminar extrudates were prepared according to the principles of Experimental Design, using a design for mixtures to assess the influence of formulation composition on the in vitro drug release from the extrudates after 1h and after 8h. The effect of each component on the two response variables was also studied. Ternary mixtures of theophylline (model drug), monohydrate lactose and microcrystalline wax (as thermoplastic binder) were extruded in a lab scale vertical ram extruder in absence of solvents at a temperature below the melting point of the binder (so that the crystalline state of the drug could be maintained), through a rectangular die to obtain suitable laminar systems. Thanks to the desirability approach and a reliability study for ensuring the quality of the formulation, a very restricted optimal zone was defined within the experimental domain. Among the mixture components, the variation of microcrystalline wax content played the most significant role in overall influence on the in vitro drug release. The formulation theophylline:lactose:wax, 57:14:29 (by weight), selected based on the desirability zone, was subsequently used for in vivo studies. The plasma profile, obtained after oral administration of the laminar extruded system in hard gelatine capsules, revealed the typical trend of an oral retard formulation. The application of the mixture experimental design associated to a desirability function permitted to optimize the extruded system and to determine the composition space that ensures final product quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Composite materials design and applications

    CERN Document Server

    Gay, Daniel; Tsai, Stephen W

    2002-01-01

    PART ONE. PRINCIPLES OF CONSTRUCTIONCOMPOSITE MATERIALS, INTEREST AND PROPERTIESWhat is Composite Material Fibers and MatrixWhat can be Made Using Composite Materials?Typical Examples of Interest on the Use of Composite MaterialsExamples on Replacing Conventional Solutions with CompositesPrincipal Physical PropertiesFABRICATION PROCESSESMolding ProcessesOther Forming ProcessesPractical Hints in the Manufacturing ProcessesPLY PROPERTIESIsotropy and AnisotropyCharacteristics of the Reinforcement-Matrix MixtureUnidirectional PlyWoven FabricsMats and Reinforced MatricesMultidimensional FabricsMetal Matrix CompositesTestsSANDWICH STRUCTURES:What is a Sandwich Structure?Simplified FlexureA Few Special AspectsFabrication and Design ProblemsNondestructive Quality ControlCONCEPTION AND DESIGNDesign of a Composite PieceThe LaminateFailure of LaminatesSizing of LaminatesJOINING AND ASSEMBLYRiveting and BoltingBondingInsertsCOMPOSITE MATERIALS AND AEROSPACE CONSTRUCTIONAircraftHelicoptersPropeller Blades for AirplanesTur...

  20. Method for preparing ceramic composite

    Science.gov (United States)

    Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

    1996-01-09

    A process is disclosed for preparing ceramic composite comprising blending TiC particulates, Al{sub 2}O{sub 3} particulates and nickel aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m{sup 1/2}, a hardness equal to or greater than 18 GPa. 5 figs.

  1. Mixtures and their risk assessment in toxicology.

    Science.gov (United States)

    Mumtaz, Moiz M; Hansen, Hugh; Pohl, Hana R

    2011-01-01

    For communities generally and for persons living in the vicinity of waste sites specifically, potential exposures to chemical mixtures are genuine concerns. Such concerns often arise from perceptions of a site's higher than anticipated toxicity due to synergistic interactions among chemicals. This chapter outlines some historical approaches to mixtures risk assessment. It also outlines ATSDR's current approach to toxicity risk assessment. The ATSDR's joint toxicity assessment guidance for chemical mixtures addresses interactions among components of chemical mixtures. The guidance recommends a series of steps that include simple calculations for a systematic analysis of data leading to conclusions regarding any hazards chemical mixtures might pose. These conclusions can, in turn, lead to recommendations such as targeted research to fill data gaps, development of new methods using current science, and health education to raise awareness of residents and health care providers. The chapter also provides examples of future trends in chemical mixtures assessment.

  2. Combustion of stratified hydrogen-air mixtures in the 10.7 m3 Combustion Test Facility cylinder

    International Nuclear Information System (INIS)

    Whitehouse, D.R.; Greig, D.R.; Koroll, G.W.

    1996-01-01

    This paper presents preliminary results from hydrogen concentration gradient combustion experiments in a 10.7 m 3 cylinder. These gradients, also referred to as stratified mixtures, were formed from dry mixtures of hydrogen and air at atmospheric temperature. Combustion pressures, burn fractions and flame speeds in concentration gradients were compared with combustion of well-mixed gases containing equivalent amounts of hydrogen. The studied variables included the quantity of hydrogen in the vessel, the steepness of the concentration gradient, the igniter location, and the initial concentration of hydrogen at the bottom of the vessel. Gradients of hydrogen and air with average concentrations of hydrogen below the downward propagation limit produced significantly greater combustion pressures when ignited at the top of the vessel than well-mixed gases with the same quantity of hydrogen. This was the result of considerably higher burn fractions in the gradients than in the well-mixed gas tests. Above the downward propagation limit, gradients of hydrogen ignited at the top of the vessel produced nearly the same combustion pressures as under well-mixed conditions; both gradients and well-mixed gases had high burn fractions. Much higher flame speeds were observed in the gradients than the well-mixed gases. Gradients and well-mixed gases containing up to 14% hydrogen ignited at the bottom of the vessel produced nearly the same combustion pressures. Above 14% hydrogen, gradients produced lower combustion pressures than well-mixed gases having the same quantity of hydrogen. This can be attributed to lower burn fractions of fuel from the gradients compared with well-mixed gases with similar quantities of hydrogen. When ignited at the bottom of the vessel, 90% of a gradient's gases remained unburned until several seconds after ignition. The remaining gases were then consumed at a very fast rate. (orig.)

  3. Catalytic Gasification of Coal using Eutectic Salt Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Atul Sheth; Pradeep Agrawal; Yaw D. Yeboah

    1998-12-04

    eutectic salt mixture consisting of Li- Na- and K- carbonates has the potential as gasification catalyst. To verify the literature reported, melting points for various compositions consisting of these three salts and the temperature range over which the mixture remained molten were determined in the lab. For mixtures with different concentrations of the three salts, the temperatures at which the mixtures were found to be in complete molten state were recorded. By increasing the amount of Li2CO3, the melting temperature range was reduced significantly. In the literature, the eutectic mixtures of Li- Na- and K-carbonates are claimed to have a lower activation energy than that of K2CO3 alone and they remain molten at a lower temperature than pure K2CO3. The slow increase in the gasification rates with eutectics reported in the literature is believed to be due to a gradual penetration of the coals and coal char particles by the molten and viscous catalyst phase. The even spreading of the salt phase seems to increase the overall carbon conversion rate. In the next reporting period, a number of eutectic salts and methods of their application on the coal will be identified and tested.

  4. Some properties of explosive mixtures containing peroxides

    Energy Technology Data Exchange (ETDEWEB)

    Zeman, Svatopluk [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice (Czech Republic)], E-mail: svatopluk.zeman@upce.cz; Trzcinski, Waldemar A. [Institute of Chemistry, Military University of Technology, PL-00-908 Warsaw 49 (Poland); Matyas, Robert [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice (Czech Republic)

    2008-06-15

    This study concerns mixtures of triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP) and ammonium nitrate (AN) with added water (W), as the case may be, and dry mixtures of TATP with urea nitrate (UN). Relative performances (RP) of the mixtures and their individual components, relative to TNT, were determined by means of ballistic mortar. The detonation energies, E{sub 0}, and detonation velocities, D, were calculated for the mixtures studied by means of the thermodynamic code CHEETAH. Relationships have been found and are discussed between the RP and the E{sub 0} values related to unit volume of gaseous products of detonation of these mixtures. These relationships together with those between RP and oxygen balance values of the mixtures studied indicate different types of participation of AN and UN in the explosive decomposition of the respective mixtures. Dry TATP/UN mixtures exhibit lower RP than analogous mixtures TATP/AN containing up to 25% of water. Depending on the water content, the TATP/AN mixtures possess higher detonability values than the ANFO explosives. A semi-logarithmic relationship between the D values and oxygen coefficients has been derived for all the mixtures studied at the charge density of 1000 kg m{sup -3}. Among the mixtures studied, this relationship distinguishes several samples of the type of 'tertiary explosives' as well as samples that approach 'high explosives' in their performances and detonation velocities.

  5. Method for separating gaseous mixtures of isotopes

    International Nuclear Information System (INIS)

    Neimann, H.J.; Schuster, E.; Kersting, A.

    1976-01-01

    A gaseous mixture of isotopes is separated by laser excitation of the isotope mixture with a narrow band of wavelengths, molecularly exciting mainly the isotope to be separated and thereby promoting its reaction with its chemical partner which is excited in a separate chamber. The excited isotopes and the chemical partner are mixed, perhaps in a reaction chamber to which the two excited components are conducted by very short conduits. The improvement of this method is the physical separation of the isotope mixture and its partner during excitation. The reaction between HCl and the mixture of 238 UF 6 and 235 UF 6 is discussed

  6. Shear viscosity of liquid mixtures: Mass dependence

    International Nuclear Information System (INIS)

    Kaushal, Rohan; Tankeshwar, K.

    2002-06-01

    Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model. (author)

  7. Evaluation of mastic in bituminous mixtures

    OpenAIRE

    Silva, Hugo Manuel Ribeiro Dias da; Pais, Jorge C.; Pereira, Paulo A. A.

    2002-01-01

    The efficiency of the asphalt-aggregate bond is one of the key factors which affects the mechanical resistance of bituminous mixtures and a better understanding of its performance allows the behaviour of mixture to be more accurately predicted. The asphalt-aggregate bond depends on the properties of the mastic and the mixture of fine aggregate and bitumen which bonds itself to the larger sized particles within the bituminous mixture. This mastic plays an im-portant role in the asphalt-aggr...

  8. Shear viscosity of liquid mixtures Mass dependence

    CERN Document Server

    Kaushal, R

    2002-01-01

    Expressions for zeroth, second, and fourth sum rules of transverse stress autocorrelation function of two component fluid have been derived. These sum rules and Mori's memory function formalism have been used to study shear viscosity of Ar-Kr and isotopic mixtures. It has been found that theoretical result is in good agreement with the computer simulation result for the Ar-Kr mixture. The mass dependence of shear viscosity for different mole fraction shows that deviation from ideal linear model comes even from mass difference in two species of fluid mixture. At higher mass ratio shear viscosity of mixture is not explained by any of the emperical model.

  9. Minimally refined biomass fuel. [carbohydrate-water-alcohol mixture

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, R.K.; Hirschfeld, T.B.

    1981-03-26

    A minimally refined fluid composition, suitable as a fuel mixture and derived from biomass material, is comprised of one or more water-soluble carbohydrates such as sucrose, one or more alcohols having less than four carbons, and water. The carbohydrate provides the fuel source; water-solubilizes the carbohydrate; and the alcohol aids in the combustion of the carbohydrate and reduces the viscosity of the carbohydrate/water solution. Because less energy is required to obtain the carbohydrate from the raw biomass than alcohol, an overall energy savings is realized compared to fuels employing alcohol as the primary fuel.

  10. Penning transfer in argon-based gas mixtures

    CERN Document Server

    Sahin, O; Tapan, I; Ozmutlu, E N

    2010-01-01

    Penning transfers, a group of processes by which excitation energy is used to ionise the gas, increase the gas gain in some detectors. Both the probability that such transfers occur and the mechanism by which the transfer takes place, vary with the gas composition and pressure. With a view to developing a microscopic electron transport model that takes Penning transfers into account, we use this dependence to identify the transfer mechanisms at play. We do this for a number of argon-based gas mixtures, using gain curves from the literature.

  11. Prospective environmental risk assessment of mixtures in wastewater treatment plant effluents - Theoretical considerations and experimental verification.

    Science.gov (United States)

    Coors, Anja; Vollmar, Pia; Sacher, Frank; Polleichtner, Christian; Hassold, Enken; Gildemeister, Daniela; Kühnen, Ute

    2018-04-14

    identity of substances composing environmental mixtures such as WWTP effluents is typically unknown. Therefore, a mixture assessment factor is discussed as an option for a prospective ERA of mixtures of unknown composition. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Hypolipidaemic effect of vegetable and cereal dietary mixtures from Egyptian sources

    Energy Technology Data Exchange (ETDEWEB)

    Rashed, M. M.; Shallan, M.; Mohamed, D. A.; Fouda, K.; Hanna, L. M.

    2010-07-01

    Hyperlipidaemia is a predominant risk factor for atherosclerosis and associated cardiovascular diseases (CVD). The international guidelines issued by the World Health Organization recommend a reduction in dietary saturated fat and cholesterol intake as a means to prevent hypercholesterolemia and CVD; however, only limited data are available on the benefits of vegetable consumption on CVD risk factors. The aim of this study was to prepare two powder mixtures containing vegetables and cereals and to evaluate their effect in hyperlipidaemic rats. The first mixture was prepared from whole wheat, cabbage, parsley and pepper, while the second mixture was prepared from whole wheat, red beet root, parsley and pepper. Whole wheat was used as a source of dietary fiber, while cabbage and beetroot were used as sources of glucosinolates (GLS) and betalains respectively as well as dietary fiber. The chemical compositions of these mixtures were determined. The safety of these mixtures was also evaluated by examining liver and kidney functions. The chemical compositions of the powder mixtures revealed that mixtures (1) and (2) contain 19.1% and 13.3% protein, 2.1% and 2.5 % fat, 69.6% and 77.5% carbohydrates, 1.8% and 1.2% crude fibers, 7.4% and 5.5% ash and 18.3% and 16.8% dietary fibers respectively. Vitamin E was 7.4 and 4.5 mg/100g in mixtures (1) and (2) respectively. {beta}-carotene was 830 and 786{mu}g/100g in mixtures (1) and (2) respectively. Total phenolic compounds were 1910 and 1710 mg as gallic acid equivalents/100g in mixtures (1) and (2) respectively. The results of the animal experiment showed a non-significant reduction in final body weight and body weight gain in rats fed the control diet containing mixture (1) or (2) when compared with different groups. Rats fed the control diet containing mixture (1) or (2) showed a significant reduction in plasma total lipids, T-Ch, LDL-Ch, TG and the ratio of T-Ch /HDLCh in different degrees, while HDL-Ch increased

  13. Thermodynamics of mixtures containing amines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)], E-mail: jagl@termo.uva.es; Mozo, Ismael; Garcia de la Fuente, Isaias; Cobos, Jose Carlos [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Riesco, Nicolas [Department of Chemical Engineering, Loughborough University, Loughborough, LE113TU Leicestershire (United Kingdom)

    2008-01-30

    Mixtures with dimethyl or trimethylpyridines and alkane, aromatic compound or 1-alkanol have been examined using different theories: DISQUAC, Flory, the concentration-concentration structure factor, S{sub CC}(0), or the Kirkwood-Buff formalism. DISQUAC represents fairly well the available experimental data, and improves theoretical calculations from Dortmund UNIFAC. Two important effects have been investigated: (i) the effect of increasing the number of methyl groups attached to the aromatic ring of the amine; (ii) the effect of modifying the position of the methyl groups in this ring. The molar excess enthalpy, H{sup E}, and the molar excess volume, V{sup E}, decrease in systems with alkane or methanol as follows: pyridine > 3-methylpyridine > 3,5-dimethylpyridine and pyridine > 2-methylpyridine > 2,4-dimethylpyridine > 2,4,6-trimethylpyridine, which has been attributed to a weakening of the amine-amine interactions in the same sequences. This is in agreement with the relative variation of the effective dipole moment, {mu}-bar, and of the differences between the boiling temperature of a pyridine base and that of the homomorphic alkane. For heptane solutions, the observed H{sup E} variation, H{sup E} (3,5-dimethylpyridine) > H{sup E} (2,4-dimethylpyridine) > H{sup E} (2,6-dimethylpyridine), is explained similarly. Calculations on the basis of the Flory model confirm that orientational effects become weaker in systems with alkane in the order: pyridine > methylpyridine > dimethylpyridine > trimethylpyridine. S{sub CC}(0) calculations show that steric effects increase with the number of CH{sub 3}- groups in the pyridine base, and that the steric effects exerted by methyl groups in positions 2 and 6 are higher than when they are placed in positions 3 and 5. The hydrogen bond energy in methanol mixtures is independent of the pyridine base, and it is estimated to be -35.2 kJ mol{sup -1}. Heterocoordination in these solutions is due in part to size effects. Their

  14. A numerical model for boiling heat transfer coefficient of zeotropic mixtures

    Science.gov (United States)

    Barraza Vicencio, Rodrigo; Caviedes Aedo, Eduardo

    2017-12-01

    Zeotropic mixtures never have the same liquid and vapor composition in the liquid-vapor equilibrium. Also, the bubble and the dew point are separated; this gap is called glide temperature (Tglide). Those characteristics have made these mixtures suitable for cryogenics Joule-Thomson (JT) refrigeration cycles. Zeotropic mixtures as working fluid in JT cycles improve their performance in an order of magnitude. Optimization of JT cycles have earned substantial importance for cryogenics applications (e.g, gas liquefaction, cryosurgery probes, cooling of infrared sensors, cryopreservation, and biomedical samples). Heat exchangers design on those cycles is a critical point; consequently, heat transfer coefficient and pressure drop of two-phase zeotropic mixtures are relevant. In this work, it will be applied a methodology in order to calculate the local convective heat transfer coefficients based on the law of the wall approach for turbulent flows. The flow and heat transfer characteristics of zeotropic mixtures in a heated horizontal tube are investigated numerically. The temperature profile and heat transfer coefficient for zeotropic mixtures of different bulk compositions are analysed. The numerical model has been developed and locally applied in a fully developed, constant temperature wall, and two-phase annular flow in a duct. Numerical results have been obtained using this model taking into account continuity, momentum, and energy equations. Local heat transfer coefficient results are compared with available experimental data published by Barraza et al. (2016), and they have shown good agreement.

  15. Theoretical analysis of a combined power and ejector refrigeration cycle using zeotropic mixture

    International Nuclear Information System (INIS)

    Yang, Xingyang; Zhao, Li; Li, Hailong; Yu, Zhixin

    2015-01-01

    Highlights: • A combined power and refrigeration cycle using zeotropic mixture is analyzed. • The cycle performances with different mixture compositions are compared. • Both exergy and parametric analysis of the combined cycle are conducted. - Abstract: A theoretical study on a combined power and ejector refrigeration cycle using zeotropic mixture isobutane/pentane is carried out. The performances of different mixture compositions are compared. An exergy analysis is conducted for the cycle. The result reveals that most exergy destruction happens in the ejector, where more than 40% exergy is lost. The heat exchange in generator causes the second largest exergy loss, larger than 28%. As the mass fraction of isobutane changes ranges from 100% to 0%, the relative exergy destruction of each component is also changing. And mixture isobutane/pentane (50/50) has the maximum exergy efficiency of 7.83%. The parametric analysis of generator temperature, condenser temperature and evaporator temperature for all the mixtures shows that, all these three thermodynamic parameters have a strong effect on the cycle performance.

  16. An oxyde mixture fuel containing uranium and plutonium dioxides and process to obtain this oxyde mixture

    International Nuclear Information System (INIS)

    Hannerz, K.

    1976-01-01

    An oxide-mixture fuel containing uranium and plutonium dioxides having the slage of spherical, or nearly spherical, oxide-mixture particles with a diameter within the range of from 0.2 to 2 mn charactarized in that each oxide-mixture particles is provided with an outer layer comprising mainly UO2, the thickness of which is at least 0.05; whereas the inner portion of the oxide-mixture particles comprises mainly PUO 2

  17. Evaluation of Skid Resistance of Wearing Course Made Of Stone Mastic Asphalt Mixture in Laboratory Conditions

    Science.gov (United States)

    Wasilewska, Marta

    2017-10-01

    This paper presents the comparison of skid resistance of wearing course made of SMA (Stone Mastic Asphalt) mixtures which differ in resistance to polishing of coarse aggregate. Dolomite, limestone, granite and trachybasalt were taken for investigation. SMA mixtures have the same nominal size of aggregate (11 mm) and very similar aggregate particle-size distribution in mineral mixtures. Tested SMA11 mixtures were designed according to EN 13108-5 and Polish National Specification WT-2: 2014. Evaluation of the skid resistance has been performed using the FAP (Friction After Polishing) test equipment also known as the Wehner/Schulze machine. Laboratory method enables to compare the skid resistance of different types of mixtures under specified conditions simulating polishing processes. Tests were performed on both the specimens made of each coarse aggregate and SMA11 mixtures containing these aggregates. Measuring of friction coefficient μm was conducted before and during polishing process up to 180 0000 passes of polishing head. Comparison of the results showed differences in sensitivity to polishing among particular mixtures which depend on the petrographic properties of rock used to produce aggregate. Limestone and dolomite tend to have a fairly uniform texture with low hardness which makes these rock types susceptible to rapid polishing. This caused lower coefficient of friction for SMA11 mixtures with limestone and dolomite in comparison with other test mixtures. These significant differences were already registered at the beginning of the polishing process. Limestone aggregate had lower value of μm before starting the process than trachybasalt and granite aggregate after its completion. Despite the differences in structure and mineralogical composition between the granite and trachybasalt, slightly different values of the friction coefficient at the end of polishing were obtained. Images of the surface were taken with the optical microscope for better

  18. Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.

    1994-01-01

    The present research reports on the effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures. Experimental and theoretical research related to combustion phenomena in hydrogen-air-steam mixtures has been ongoing for many years. However, detonation cell size data currently exists or hydrogen-air-steam mixtures up to a temperature of only 400K. Sever accident scenarios have been identified for light water reactors (LWRs) where hydrogen-air mixture temperatures in excess of 400K could be generated within containment. The experiments in this report focus on extending the cell size data base for initial mixture temperatures in excess of 400K. The experiments were carried out in a 10-cm inner-diameter, 6.1-m long heated detonation tube with a maximum operating temperature of 700K and spatial temperature uniformity of ±14K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300K--650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15 percent by hydrogen at 300K down to about 9 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments

  19. Process Dissociation and Mixture Signal Detection Theory

    Science.gov (United States)

    DeCarlo, Lawrence T.

    2008-01-01

    The process dissociation procedure was developed in an attempt to separate different processes involved in memory tasks. The procedure naturally lends itself to a formulation within a class of mixture signal detection models. The dual process model is shown to be a special case. The mixture signal detection model is applied to data from a widely…

  20. Buffer gas cooling and mixture analysis

    Science.gov (United States)

    Patterson, David S.; Doyle, John M.

    2018-03-06

    An apparatus for spectroscopy of a gas mixture is described. Such an apparatus includes a gas mixing system configured to mix a hot analyte gas that includes at least one analyte species in a gas phase into a cold buffer gas, thereby forming a supersaturated mixture to be provided for spectroscopic analysis.

  1. Unfolding the potential of wheat cultivar mixtures

    DEFF Research Database (Denmark)

    Borg, J.; Kiær, Lars Pødenphant; Lecarpentier, C.

    2018-01-01

    and they are not encouraged by advisory services. Based on the methodology developed by Kiær et al. (2009), we achieved a meta-analysis of cultivar mixtures in wheat. Among the 120 publications dedicated to wheat, we selected 32 studies to analyze various factors that may condition the success or failure of wheat mixtures...

  2. Separation of organic azeotropic mixtures by pervaporation

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W.

    1991-12-01

    Distillation is a commonly used separation technique in the petroleum refining and chemical processing industries. However, there are a number of potential separations involving azetropic and close-boiling organic mixtures that cannot be separated efficiently by distillation. Pervaporation is a membrane-based process that uses selective permeation through membranes to separate liquid mixtures. Because the separation process is not affected by the relative volatility of the mixture components being separated, pervaporation can be used to separate azetropes and close-boiling mixtures. Our results showed that pervaporation membranes can be used to separate azeotropic mixtures efficiently, a result that is not achievable with simple distillation. The membranes were 5--10 times more permeable to one of the components of the mixture, concentrating it in the permeate stream. For example, the membrane was 10 times more permeable to ethanol than methyl ethyl ketone, producing 60% ethanol permeate from an azeotropic mixture of ethanol and methyl ethyl ketone containing 18% ethanol. For the ethyl acetate/water mixture, the membranes showed a very high selectivity to water (> 300) and the permeate was 50--100 times enriched in water relative to the feed. The membranes had permeate fluxes on the order of 0.1--1 kg/m{sup 2}{center dot}h in the operating range of 55--70{degrees}C. Higher fluxes were obtained by increasing the operating temperature.

  3. Process of decomposing an oil mixture

    Energy Technology Data Exchange (ETDEWEB)

    Kubierschky, K

    1917-12-02

    A process is described for the decomposition of oil mixtures, and the like, by means of alcohol, characterized in that the subject mixture is brought into solution in high-grade alcohol, and this solution is washed countercurrent with dilute alcohol.

  4. Mixture Modeling: Applications in Educational Psychology

    Science.gov (United States)

    Harring, Jeffrey R.; Hodis, Flaviu A.

    2016-01-01

    Model-based clustering methods, commonly referred to as finite mixture modeling, have been applied to a wide variety of cross-sectional and longitudinal data to account for heterogeneity in population characteristics. In this article, we elucidate 2 such approaches: growth mixture modeling and latent profile analysis. Both techniques are…

  5. Intelligent gas-mixture flow sensor

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Dijkstra, Fred; Houkes, Z.; van Kuijk, J.C.C.; van Kuijk, Joost

    A simple way to realize a gas-mixture flow sensor is presented. The sensor is capable of measuring two parameters from a gas flow. Both the flow rate and the helium content of a helium-nitrogen gas mixture are measured. The sensor exploits two measurement principles in combination with (local)

  6. Shock formation in mixtures of fluids

    International Nuclear Information System (INIS)

    Virgopia, N.; Ferraioli, F.

    1987-01-01

    The problem of weak-discontinuity propagation in mixtures of two ideal fluids is examined. The presence of exchenge of momentum reduces or enhances the time for shock formation depending on the machanism with whom the exchange of momentum takes place. Numerical evaluation are also presented for mixtures of nitrogen and oxygen simulating dry-air models

  7. The Modified Enskog Equation for Mixtures

    NARCIS (Netherlands)

    Beijeren, H. van; Ernst, M.H.

    1973-01-01

    In a previous paper it was shown that a modified form of the Enskog equation, applied to mixtures of hard spheres, should be considered as the correct extension of the usual Enskog equation to the case of mixtures. The main argument was that the modified Enskog equation leads to linear transport

  8. Inflammable gax mixtures in biogas facilities; Entzuendbare Gasgemische in Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Volkmar; Pahl, Robert [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany). Fachbereich 2.1 ' Gase, Gasanlagen'

    2013-09-15

    The number of the biogas facilities in Germany has strongly increased with the extension of regenerative energy. In the facilities by decomposition of organic matter inflammable biogas is obtained, which strongly fluctuates in its composition. The main components of biogas are methane and carbon dioxide, but also depending on the process-level water vapor, nitrogen,oxygen, and impurities, which may partly be toxic. In addition it is begun to work up biogas in larger facilities in order to feed it directly in the natural-gas network. In the development are currently also coupled biogas and electrolysis facilities. By means of the electrolysis of water also surpluses of electrical energy from wind and solar facilities can be processed to hydrogen (power-to-gas technology). In order to make reliable data for the explosion protection in the handling with the gas mixtures present in the facilities available, the BAM has in the last years measured explosion ranges of mixtures of methane, hydrogen, carbon dioxide, water vapor, air, and oxygen in accordance with the standard EN 1839 and made available as key data. By means of these data the explosion ability of the gas mixtures in biogas facilities can be reliably estimated. On this base corresponding explosion-protection actions can be taken.

  9. Isotope and mixture effects on neoclassical transport in the pedestal

    Science.gov (United States)

    Pusztai, Istvan; Buller, Stefan; Omotani, John T.; Newton, Sarah L.

    2017-10-01

    The isotope mass scaling of the energy confinement time in tokamak plasmas differs from gyro-Bohm estimates, with implications for the extrapolation from current experiments to D-T reactors. Differences in mass scaling in L-mode and various H-mode regimes suggest that the isotope effect may originate from the pedestal. In the pedestal, sharp gradients render local diffusive estimates invalid, and global effects due to orbit-width scale profile variations have to be taken into account. We calculate neoclassical cross-field fluxes from a radially global drift-kinetic equation using the PERFECT code, to study isotope composition effects in density pedestals. The relative reduction to the peak heat flux due to global effects as a function of the density scale length is found to saturate at an isotope-dependent value that is larger for heavier ions. We also consider D-T and H-D mixtures with a focus on isotope separation. The ability to reproduce the mixture results via single-species simulations with artificial ``DT'' and ``HD'' species has been considered. These computationally convenient single ion simulations give a good estimate of the total ion heat flux in corresponding mixtures. Funding received from the International Career Grant of Vetenskapsradet (VR) (330-2014-6313) with Marie Sklodowska Curie Actions, Cofund, Project INCA 600398, and Framework Grant for Strategic Energy Research of VR (2014-5392).

  10. Contributory Factors Related to Permanent Deformation of Hot Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Alaa Husein Abd

    2017-03-01

    Full Text Available Permanent deformation (Rutting of asphalt pavements which appears in many roads in Iraq, have caused a major impact on pavement performance by reducing the useful service life of pavement and creating services hazards for highway users. The main objective of this research is investigating the effect of some contributory factors related to permanent deformation of asphalt concrete mixture. To meet the objectives of this research, available local materials are used including asphalt binder, aggregates, mineral filler and modified asphalt binder. The Superpave mix design system was adopted with varying volumetric compositions. The Superpave Gyratory Compactor was used to compact 24 asphalt concrete cylindrical specimens. To collect the required data and investigate the development of permanent deformation in asphalt concrete under repeated loadings, Wheel-Tracking apparatus has been used in a factorial testing program during which 44 slab samples; with dimensions of 400×300×50 mm; were tested to simulate . actual pavement. Based on wheel-tracking test results, it has been concluded that increasing the compaction temperature from 110 to 150ºC caused a decreasing in permanent deformation by 20.5 and 15.6 percent for coarse and fine gradation control asphalt mixtures respectively. While the permanent deformation decreased about 21.3 percent when the compaction temperature is increased from 110 to 150ºC for coarse gradation asphalt mixtures modified with styrene butadiene styrene SBS with 3 percent by asphalt binder weight.

  11. Dissolution and biodegradation of a mixture of immiscible liquids

    International Nuclear Information System (INIS)

    Gandhi, P.; Erickson, L.E.; Fan, L.T.

    1994-01-01

    Subsurface contaminants are frequently encountered as mixtures of nonaqueous phase liquids (NAPLs) at sites contaminated by gasoline or coal tar comprising organic mixtures. The leaching of these organic mixtures from the aquifer has been examined with and without biodegradation. The results obtained have been compared with the limiting case of a single component NAPL. Various physical processes involved have been quantified based on the assumptions that liquid-liquid and sorption equilibria are established at the beginning of each flushing; oxygen required for biochemical oxidation is completely consumed by the end of each flushing; and the rate of biochemical oxidation obeys the Monod kinetics for a multi-substrate system, characterized by an oxygen utilization factor. This has given rise to an equilibrium model expressing the mass fraction of any component remaining in the aquifer, its aqueous concentration, and the composition of the NAPL as functions of the number of flushings. The results of the simulation with the model demonstrate that bioremediation can significantly reduce the time necessary for removing the components of intermediate solubility such as xylene. Highly soluble components of the NAPL are mainly removed by the pump-and-treat mechanism while the components of extremely low solubility are unavailable to the microbes as substrates in a multi-component system

  12. A novel coarsening mechanism of droplets in immiscible fluid mixtures

    Science.gov (United States)

    Shimizu, Ryotaro; Tanaka, Hajime

    2015-06-01

    In our daily lives, after shaking a salad dressing, we see the coarsening of oil droplets suspended in vinegar. Such a demixing process is observed everywhere in nature and also of technological importance. For a case of high droplet density, domain coarsening proceeds with inter-droplet collisions and the resulting coalescence. This phenomenon has been explained primarily by the so-called Brownian-coagulation mechanism: stochastic thermal forces exerted by molecules induce random motion of individual droplets, causing accidental collisions and subsequent interface-tension-driven coalescence. Contrary to this, here we demonstrate that the droplet motion is not random, but hydrodynamically driven by the composition Marangoni force due to an interfacial tension gradient produced in each droplet as a consequence of composition correlation among droplets. This alters our physical understanding of droplet coarsening in immiscible liquid mixtures on a fundamental level.

  13. NMR study of thallium(I) ions in molten binary mixtures of nitrates and chlorides

    International Nuclear Information System (INIS)

    Nakamura, Yoshio; Kitazawa, Yukiharu; Shimoji, Mitsuo; Shimokawa, Shigezo.

    1983-01-01

    The chemical shifts of 205 Tl NMR in molten binary mixtures of nitrates and those of chlorides have been measured as a function of composition and temperature. The shifts increase in the diamagnetic direction with decreasing the size of foreign cations and increase in the paramagnetic direction with increasing temperature. These results are interpreted by changes in the overlap of orbitals of the Tl + ion and the anion, which depend upon composition and temperature. (author)

  14. The (water + acetonitrile) mixture revisited: A new approach for calculating partial molar volumes

    International Nuclear Information System (INIS)

    Carmen Grande, Maria del; Julia, Jorge Alvarez; Barrero, Carmen R.; Marschoff, Carlos M.; Bianchi, Hugo L.

    2006-01-01

    Density and viscosity of (water + acetonitrile) mixtures were measured over the whole composition range at the temperatures: (298.15, 303.15, 308.15, 313.15, and 318.15) K. A new mathematical approach was developed which allows the calculation of the derivatives of density with respect to composition avoiding the appearance of local discontinuities. Thus, reliable partial molar volumes and thermal expansion coefficients were obtained

  15. Mixture toxicity of PBT-like chemicals

    DEFF Research Database (Denmark)

    Syberg, Kristian; Dai, Lina; Ramskov, Tina

    addition is a suitable model for default estimations of mixture effects. One of the major challenges is therefore how to select specific chemicals for actual mixture toxicity assessments. Persistant chemicals are likely to be present in the environment for an extended period of time, thus increasing...... the likelihood of them being present in environmentally found mixtures. Persistant, bioaccumulative and toxic (PBT) chemicals are therefore a highly relevant group of chemicals to consider for mixture toxicity regulation. The present study evaluates to what extent a number of PBT-like chemicals posess concern...... beyond that of the individual components. Firstly, the effects of three chemicals with PBT-like properties (acetyl cedrene, pyrene and triclosan) was examined on the freshwater snail, Potamopyrgus antipodarum. Secondly, mixture bioaccumulation of the same three chemicals were assessed experimentally...

  16. A binary mixture operated heat pump

    International Nuclear Information System (INIS)

    Hihara, E.; Saito, T.

    1991-01-01

    This paper evaluates the performance of possible binary mixtures as working fluids in high- temperature heat pump applications. The binary mixtures, which are potential alternatives of fully halogenated hydrocarbons, include HCFC142b/HCFC22, HFC152a/HCFC22, HFC134a/HCFC22. The performance of the mixtures is estimated by a thermodynamic model and a practical model in which the heat transfer is considered in heat exchangers. One of the advantages of binary mixtures is a higher coefficient of performance, which is caused by the small temperature difference between the heat-sink/-source fluid and the refrigerant. The mixture HCFC142b/HCFC22 is promising from the stand point of thermodynamic performance

  17. Radiolytic decomposition of water-ethanol mixtures

    International Nuclear Information System (INIS)

    Baquey, Charles

    1968-07-01

    This research thesis addresses the study of the behaviour of binary mixtures submitted to ionizing radiations, and notably aims, by studying the case of water-ethanol mixtures, at verifying solutions proposed by previously published works on the origin of hydrogen atoms and of molecular hydrogen, on the intervention of excited atoms, and on the origin of products appearing under radiolysis. The experimental part of this work consists in the dosing of products formed in water-ethanol mixtures irradiated in presence or absence of nitrate, hydrogen, hydrocarbon, acetaldehyde, 2-3 butanediol and nitrite. Results are discussed and interpreted in terms of acetaldehyde efficiency, 2-3 butanediol efficiencies, and hydrocarbon efficiencies in pure ethanol, and in water-ethanol mixtures. The influence of the presence of nitrate ions in mixtures is also discussed

  18. Deformation Properties and Fatigue of Bituminous Mixtures

    Directory of Open Access Journals (Sweden)

    Frantisek Schlosser

    2013-01-01

    Full Text Available Deformation properties and fatigue performance are important characteristics of asphalt bound materials which are used for construction of pavement layers. Viscoelastic asphalt mixtures are better characterized via dynamic tests. This type of tests allows us to collate materials with regard to axle vibrations which lie usually in the range of 6 Hz–25 Hz for standard conditions. Asphalt modified for heat sensitivity in the range from −20°C to +60°C has significant impact on the overall characteristics of the mixture. Deformation properties are used as inputs for empirical mixture design, and fatigue performance of asphalt mixtures reflects the parameters of functional tests. Master curves convey properties of asphalt mixtures for various conditions and allow us to evaluate them without the need of time expensive testing.

  19. Dielectric and physiochemical study of binary mixture of nitrobenzene with toluene

    Science.gov (United States)

    Mohod, Ajay G.; Deshmukh, S. D.; Pattebahadur, K. L.; Undre, P. B.; Patil, S. S.; Khirade, P. W.

    2018-05-01

    This paper presents the study of binary mixture of Nitrobenzene (NB) with Toluene (TOL) for eleven different concentrations at room temperature. The determined Dielectric Constant (ɛ0) Density (ρ) and Refractive index (nD) values of binary mixture are used to calculate the excess properties i.e. Excess Dielectric Constant (ɛ0E), Excess Molar Volume (VmE), Excess Refractive Index (nDE) and Excess Molar Refraction (RmE) of mixture over the entire composition range and fitted to the Redlich-Kister equation. The Kirkwood Correlation Factor (geff) and other parameters were used to discuss the information about the orientation of dipoles and the solute-solvent interaction of binary mixture at molecular level over the entire range of concentration.

  20. Experimental measurements and prediction of liquid densities for n-alkane mixtures

    International Nuclear Information System (INIS)

    Ramos-Estrada, Mariana; Iglesias-Silva, Gustavo A.; Hall, Kenneth R.

    2006-01-01

    We present experimental liquid densities for n-pentane, n-hexane and n-heptane and their binary mixtures from (273.15 to 363.15) K over the entire composition range (for the mixtures) at atmospheric pressure. A vibrating tube densimeter produces the experimental densities. Also, we present a generalized correlation to predict the liquid densities of n-alkanes and their mixtures. We have combined the principle of congruence with the Tait equation to obtain an equation that uses as variables: temperature, pressure and the equivalent carbon number of the mixture. Also, we present a generalized correlation for the atmospheric liquid densities of n-alkanes. The average absolute percentage deviation of this equation from the literature experimental density values is 0.26%. The Tait equation has an average percentage deviation of 0.15% from experimental density measurements

  1. Influence of high power ultrasound on rheological and foaming properties of model ice-cream mixtures

    Directory of Open Access Journals (Sweden)

    Verica Batur

    2010-03-01

    Full Text Available This paper presents research of the high power ultrasound effect on rheological and foaming properties of ice cream model mixtures. Ice cream model mixtures are prepared according to specific recipes, and afterward undergone through different homogenization techniques: mechanical mixing, ultrasound treatment and combination of mechanical and ultrasound treatment. Specific diameter (12.7 mm of ultrasound probe tip has been used for ultrasound treatment that lasted 5 minutes at 100 percent amplitude. Rheological parameters have been determined using rotational rheometer and expressed as flow index, consistency coefficient and apparent viscosity. From the results it can be concluded that all model mixtures have non-newtonian, dilatant type behavior. The highest viscosities have been observed for model mixtures that were homogenizes with mechanical mixing, and significantly lower values of viscosity have been observed for ultrasound treated ones. Foaming properties are expressed as percentage of increase in foam volume, foam stability index and minimal viscosity. It has been determined that ice cream model mixtures treated only with ultrasound had minimal increase in foam volume, while the highest increase in foam volume has been observed for ice cream mixture that has been treated in combination with mechanical and ultrasound treatment. Also, ice cream mixtures having higher amount of proteins in composition had shown higher foam stability. It has been determined that optimal treatment time is 10 minutes.

  2. Combining measurements to estimate properties and characterization extent of complex biochemical mixtures; applications to Heparan Sulfate

    Science.gov (United States)

    Pradines, Joël R.; Beccati, Daniela; Lech, Miroslaw; Ozug, Jennifer; Farutin, Victor; Huang, Yongqing; Gunay, Nur Sibel; Capila, Ishan

    2016-04-01

    Complex mixtures of molecular species, such as glycoproteins and glycosaminoglycans, have important biological and therapeutic functions. Characterization of these mixtures with analytical chemistry measurements is an important step when developing generic drugs such as biosimilars. Recent developments have focused on analytical methods and statistical approaches to test similarity between mixtures. The question of how much uncertainty on mixture composition is reduced by combining several measurements still remains mostly unexplored. Mathematical frameworks to combine measurements, estimate mixture properties, and quantify remaining uncertainty, i.e. a characterization extent, are introduced here. Constrained optimization and mathematical modeling are applied to a set of twenty-three experimental measurements on heparan sulfate, a mixture of linear chains of disaccharides having different levels of sulfation. While this mixture has potentially over two million molecular species, mathematical modeling and the small set of measurements establish the existence of nonhomogeneity of sulfate level along chains and the presence of abundant sulfate repeats. Constrained optimization yields not only estimations of sulfate repeats and sulfate level at each position in the chains but also bounds on these levels, thereby estimating the extent of characterization of the sulfation pattern which is achieved by the set of measurements.

  3. Insights into Glycol Ether-Alkanol Mixtures from a Combined Experimental and Theoretical Approach.

    Science.gov (United States)

    Alcalde, Rafael; Gutiérrez, Alberto; Atilhan, Mert; Trenzado, José Luis; Aparicio, Santiago

    2017-06-08

    The binary liquid mixtures of glycol ethers (glymes) + 1-alkanol were characterized from the microscopic and macroscopic viewpoints through a combined experimental and theoretical study. Structuring, dynamics, and intermolecular forces were determined using density functional theory and classical molecular dynamics methods. The macroscopic behavior was studied though the measurement of relevant physicochemical properties and Raman IR studies. The changes in intermolecular forces with mixture composition, temperature, and the effects from the types of glymes as well as 1-alkanols were considered. Hydrogen bonding in the mixed fluids, its changes upon mixing, and mixture composition showed a large effect on fluids' structure and determined most of the fluids' properties together with the presence of hydrophobic domains from long 1-alkanols.

  4. Solution thermodynamics and preferential solvation of sulfamethazine in (methanol + water) mixtures

    International Nuclear Information System (INIS)

    Delgado, Daniel R.; Almanza, Ovidio A.; Martínez, Fleming; Peña, María A.; Jouyban, Abolghasem; Acree, William E.

    2016-01-01

    Highlights: • Solubility of sulfamethazine (SMT) was measured in (methanol + water) mixtures. • SMT solubility was correlated with Jouyban–Acree model. • Gibbs energy, enthalpy, and entropy of dissolution of SMT were calculated. • Non-linear enthalpy–entropy relationship was observed for SMT. • Preferential solvation of SMT by methanol was analyzed by using the IKBI method. - Abstract: The solubility of sulfamethazine (SMT) in {methanol (1) + water (2)} co-solvent mixtures was determined at five different temperatures from (293.15 to 313.15) K. The sulfonamide exhibited its highest mole fraction solubility in pure methanol (δ 1 = 29.6 MPa 1/2 ) and its lowest mole fraction solubility in water (δ 2 = 47.8 MPa 1/2 ) at each of the five temperatures studied. The Jouyban–Acree model was used to correlate/predict the solubility values. The respective apparent thermodynamic functions Gibbs energy, enthalpy, and entropy of solution were obtained from the solubility data through the van’t Hoff and Gibbs equations. Apparent thermodynamic quantities of mixing were also calculated for this drug using values of the ideal solubility reported in the literature. A non-linear enthalpy–entropy relationship was noted for SMT in plots of both the enthalpy vs. Gibbs energy of mixing and the enthalpy vs. entropy of mixing. These plots suggest two different trends according to the slopes obtained when the composition of the mixtures changes. Accordingly, the mechanism for SMT transfer processes in water-rich mixtures from water to the mixture with 0.70 in mass fraction of methanol is entropy driven. Conversely, the mechanism is enthalpy driven in mixtures whenever the methanol composition exceeds 0.70 mol fraction. An inverse Kirkwood–Buff integral analysis of the preferential solvation of SMT indicated that the drug is preferentially solvated by water in water-rich mixtures but is preferentially solvated by methanol in methanol-rich mixtures.

  5. Peak quantification in surface-enhanced laser desorption/ionization by using mixture models

    NARCIS (Netherlands)

    Dijkstra, Martijn; Roelofsen, Han; Vonk, Roel J.; Jansen, Ritsert C.

    2006-01-01

    Surface-enhanced laser desorption/ionization (SELDI) time of flight (TOF) is a mass spectrometry technology for measuring the composition of a sampled protein mixture. A mass spectrum contains peaks corresponding to proteins in the sample. The peak areas are proportional to the measured

  6. Excess enthalpies and (vapour + liquid) equilibrium data for the binary mixtures of dimethylsulphoxide with ketones

    International Nuclear Information System (INIS)

    Radhamma, M.; Venkatesu, P.; Rao, M.V. Prabhakara; Prasad, D.H.L.

    2007-01-01

    Excess enthalpies (H E ), at ambient pressure and T = 298.15 K, have been measured by using a solution calorimeter for the binary liquid mixtures of dimethyl sulphoxide (DMSO) with ketones, as a function of composition. The ketones chosen in the present investigation were methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CH). The H E values are positive over the entire composition range for the three binary mixtures. Furthermore, the (vapour + liquid) equilibrium (VLE) was measured at 715 Torr for these mixtures, of different compositions, with the help of Swietoslawski-ebulliometer. The experimental temperature-mole fraction (t-x) data were used to compute Wilson parameters and then used to calculate the equilibrium vapour-phase compositions as well as the theoretical points for these binary mixtures. These Wilson parameters are used to calculate activity coefficients (γ) and these in turn to calculate excess Gibbs free energy (G E ). The intermolecular interactions and structural effects were analyzed on the basis of the measured and derived properties

  7. Protein-peptide interactions in mixtures of whey peptides and whey proteins

    NARCIS (Netherlands)

    Creusot, N.; Gruppen, H.

    2007-01-01

    The effects of several conditions on the amounts and compositions of aggregates formed in mixtures of whey protein hydrolysate, made with Bacillus licheniformis protease, and whey protein isolate were investigated using response surface methodology. Next, the peptides present in the aggregates were

  8. Fouling tendency of ash resulting from burning mixtures of biofuels. Part 2: Deposit chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Mischa Theis; Bengt-Johan Skrifvars; Maria Zevenhoven; Mikko Hupa; Honghi Tranb [Aabo Akademi Process Chemistry Centre, Aabo (Finland). Combustion and Materials Chemistry

    2006-10-15

    Mixtures of peat with bark and peat with straw were burned in a lab-scale entrained flow reactor under controlled conditions, and deposits were collected on an air-cooled probe at a temperature of 550 {sup o}C. The fuel and deposit compositions were compared using chemical fractionation analysis and SEM/EDX. Chemical fractionation analysis was capable of explaining the relative fouling tendency of peat, bark, and straw. The composition of deposits obtained from firing peat, bark, and straw individually resembled the composition of their ashes. When firing peat-bark and peat-straw mixtures, it was found that the deposition rate only started to increase when the Cl/S molar ratio in the feed ash exceeded 0.15. The composition of the ensuing deposits resembled the deposits obtained from burning either bark or straw individually. For peat-bark mixtures it was concluded that the presence of S in the feed suppresses deposition by sulfating chloride compounds, leading to deposits that contain less Cl and have less molten phase. For peat-straw mixtures it was concluded that the deposition behaviour is governed by other mechanisms than the interaction of Cl and S. 27 refs., 7 figs., 1 tab.

  9. Fine tuning the ionic liquid-vacuum outer atomic surface using ion mixtures.

    Science.gov (United States)

    Villar-Garcia, Ignacio J; Fearn, Sarah; Ismail, Nur L; McIntosh, Alastair J S; Lovelock, Kevin R J

    2015-03-28

    Ionic liquid-vacuum outer atomic surfaces can be created that are remarkably different from the bulk composition. In this communication we demonstrate, using low-energy ion scattering (LEIS), that for ionic liquid mixtures the outer atomic surface shows significantly more atoms from anions with weaker cation-anion interactions (and vice versa).

  10. Increased accuracy of starch granule type quantification using mixture distributions.

    Science.gov (United States)

    Tanaka, Emi; Ral, Jean-Phillippe F; Li, Sean; Gaire, Raj; Cavanagh, Colin R; Cullis, Brian R; Whan, Alex

    2017-01-01

    The proportion of granule types in wheat starch is an important characteristic that can affect its functionality. It is widely accepted that granule types are either large, disc-shaped A-type granules or small, spherical B-type granules. Additionally, there are some reports of the tiny C-type granules. The differences between these granule types are due to its carbohydrate composition and crystallinity which is highly, but not perfectly, correlated with the granule size. A majority of the studies that have considered granule types analyse them based on a size threshold rather than chemical composition. This is understandable due to the expense of separating starch into different types. While the use of a size threshold to classify granule type is a low-cost measure, this results in misclassification. We present an alternative, statistical method to quantify the proportion of granule types by a fit of the mixture distribution, along with an R package, a web based app and a video tutorial for how to use the web app to enable its straightforward application. Our results show that the reliability of the genotypic effects increase approximately 60% using the proportions of the A-type and B-type granule estimated by the mixture distribution over the standard size-threshold measure. Although there was a marginal drop in reliability for C-type granules. The latter is likely due to the low observed genetic variance for C-type granules. The determination of the proportion of granule types from size-distribution is better achieved by using the mixing probabilities from the fit of the mixture distribution rather than using a size-threshold.

  11. Transesterification of camelina sativa oil with supercritical alcohol mixtures

    International Nuclear Information System (INIS)

    Sun, Yingqiang; Ponnusamy, Sundaravadivelnathan; Muppaneni, Tapaswy; Reddy, Harvind K.; Wang, Jun; Zeng, Zheling; Deng, Shuguang

    2015-01-01

    Highlights: • Transesterification of camelina oil under supercritical methanol/ethanol and 1-butanol mixture conditions. • Chemical composition of fatty acid methyl esters, ethyl esters and butyl esters. • Effect of different alcohol molar ratio on biodiesel yields. • Effect of different alcohol molar ratio on physical properties of biodiesel products. - Abstract: The transesterification of camelina sativa oil with methanol–1-butanol, and ethanol–1-butanol alcohol mixtures under supercritical conditions have been studied in order to maximize biodiesel yield and improve biodiesel quality. The influence of the variation of the molar ratio of methanol–1-butanol and ethanol–1-butanol from 1:0, 3:1, 2:1, 1:1, 1:2, to 0:1 on the yield of free fatty methyl esters/free fatty ethanol esters–free fatty acid butyl esters, the composition of the biodiesel blend mixtures, and the physical properties of the biodiesel have been investigated at the reaction temperature of 290 °C, reaction time of 30 min, and the initial reaction pressure of 500 psi. A maximum yield of 86.14 wt% for free fatty acid methyl esters–free fatty acid butyl esters with the optimum cold property can be obtained at the molar ratio of methanol–1-butanol of 0.5–0.9. Also, a maximum yield of 85.60 wt% for free fatty ethyl esters–free fatty butyl esters with the lowest pour point can be achieved at the molar ratio of ethanol–1-butanol in the range of 0.5–0.7

  12. Asphaltenes-based polymer nano-composites

    Science.gov (United States)

    Bowen, III, Daniel E

    2013-12-17

    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  13. Multi-temperature mixture of fluids

    Directory of Open Access Journals (Sweden)

    Ruggeri Tommaso

    2009-01-01

    Full Text Available We present a survey on some recent results concerning the different models of a mixture of compressible fluids. In particular we discuss the most realistic case of a mixture when each constituent has its own temperature (MT and we first compare the solutions of this model with the one with a unique common temperature (ST . In the case of Eulerian fluids it will be shown that the corresponding (ST differential system is a principal subsystem of the (MT one. Global behavior of smooth solutions for large time for both systems will also be discussed through the application of the Shizuta-Kawashima condition. Then we introduce the concept of the average temperature of mixture based upon the consideration that the internal energy of the mixture is the same as in the case of a single-temperature mixture. As a consequence, it is shown that the entropy of the mixture reaches a local maximum in equilibrium. Through the procedure of Maxwellian iteration a new constitutive equation for non-equilibrium temperatures of constituents is obtained in a classical limit, together with the Fick's law for the diffusion flux. Finally, to justify the Maxwellian iteration, we present for dissipative fluids a possible approach of a classical theory of mixture with multi-temperature and we prove that the differences of temperatures between the constituents imply the existence of a new dynamical pressure even if the fluids have a zero bulk viscosity.

  14. Donor free radical explosive composition

    Science.gov (United States)

    Walker, Franklin E. [15 Way Points Rd., Danville, CA 94526; Wasley, Richard J. [4290 Colgate Way, Livermore, CA 94550

    1980-04-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising an organic compound or mixture of organic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and which is not an explosive, or an inorganic compound or mixture of inorganic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and selected from ammonium or alkali metal persulfates.

  15. Probabilistic mixture-based image modelling

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Havlíček, Vojtěch; Grim, Jiří

    2011-01-01

    Roč. 47, č. 3 (2011), s. 482-500 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572; GA ČR GA102/08/0593 Grant - others:CESNET(CZ) 387/2010; GA MŠk(CZ) 2C06019; GA ČR(CZ) GA103/11/0335 Institutional research plan: CEZ:AV0Z10750506 Keywords : BTF texture modelling * discrete distribution mixtures * Bernoulli mixture * Gaussian mixture * multi-spectral texture modelling Subject RIV: BD - Theory of Information Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/RO/haindl-0360244.pdf

  16. Adsorption on mixtures of ion exchangers

    International Nuclear Information System (INIS)

    Triolo, R.; Lietzke, M.H.

    1979-01-01

    A theoretical study has been made of adsorption on mixtures of ion exchangers. The effect of variables such as the concentration of the ion being adsorbed, the concentration of the supporting electrolyte, loading, the values of the capacities and equilibrium constants for the various exchange processes, and the fraction of each adsorber in the mixture on the observed distribution coefficient has been investigated. A computer program has been written to facilitate the calculation of distribution coefficients for the adsorption of an ion on a given mixture of ion exchangers under a specified set of conditions

  17. Principles and practice of mixtures toxicology

    National Research Council Canada - National Science Library

    Mumtaz, Moiz

    2010-01-01

    ... accurate predictions for the adverse effects of mixtures has been limited by the difficulty of acquiring data for all the possible combinations of dose and time that exist even in simple mixtures. Such predictions are also compromised by our use of single-agent toxicity studies since most "realworld" exposures are to mixtures. This has resulted in a variety of approaches (models, protocols, techniques, etc.) to address these issues. These are described in detail in the two dozen chapters of this book along with ca...

  18. Deflagration of thermite - ammonium nitrate based propellant mixture

    Science.gov (United States)

    Duraes, Luisa; Morgado, Joel; Portugal, Antonio; Campos, Jose

    2001-06-01

    Reaction between iron oxide (Fe2O3) and aluminum (Al) is the reference of the classic thermite compositions. The efficency of the reaction, for a given initial composition of Fe2O3 and Al, is evaluated by the final temperature and by the mass ratio of Al2O3 /AlO in products of combustion (in condensed phase). In order to increase pressure in products of thermite reaction, the original composition is mixed, with an original twin screw extruder, with a propellant binder composed of ammonium and sodium nitrates, initialy solved in formamide (CH3NO) and mixed with a polyurethane solution. The products of combustion and pyrolysis of this binder, reacting with thermite products, generates high pressure and high temperature conditions. These experimental conditions are also predicted using THOR code. The study presents DSC and TGA results of components and mixtures, and correlates them to the ignition phenomena and reaction properties. The regression rate of combustion and final attained temperature and pressure, in a closed confinement, as a function of composition of thermite components/propellant binder, are presented and discussed. They show the influence of gaseous combustion and pyrolysis products of binder in final reaction.

  19. Thermal analysis evaluation of the reactivity of coal mixtures for injection in the blast furnace

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Ilha Gomes

    2006-03-01

    Full Text Available Pulverized Coal Injection (PCI is an important standard technology replacing coke partially by pulverized coal into the blast furnace that allows a significant reduction of hot metal costs and environmental impact, contributing to a decrease of coke requirements for ironmaking. Coals typically used in this process in Brazil are, at current time, exclusively imported from many countries, although economic important coal-measures occur in the southern part of the country. The Brazilian coals have a low rank, higher contents of inert components, proportioning nocoking properties and an expected high reactivity. Due to these caractheristics, these coals could be used for injection in the blast furnaces in order to decrease the dependency on high cost imported coals. The efficiency in the combustion and the coal reactivity are considered important parameters in the blast furnace, since a larger amount of char (unburned coal causes severe problems to the furnace operation. The aim of the present work is to compare the reactivity of a south Brazilian coal, obtained from Faxinal mine, with two imported coals and the blends of the Brazilian coal with the imported ones. The reactivity of these coals and their blends were evaluated in a thermogravimetric analyzer. In the experiments, various mass ratios of Faxinal coal and the imported coals were used to compose the blends. The gasification reaction with pure CO2 was conducted under isothermal conditions at 1050 °C and atmospheric pressure. The experimental results show the greater reactivity of the Faxinal coal. The additive behavior was confirmed. The blends with a composition of up to 50% Faxinal coal have parameters according to the usual limits used for PCI.

  20. Toxicity of binary mixtures of metals and pyrethroid insecticides to Daphnia magna Straus. Implications for multi-substance risks assessment

    Energy Technology Data Exchange (ETDEWEB)

    Barata, Carlos [Laboratory of Environmental Toxicology, Universitat Poltiecnica de Catalunya, CN 150 Km 14.5, Terrassa 08220 (Spain)]. E-mail: barata@intexter.upc.edu; Baird, D.J. [National Water Research Institute (Environment Canada) at Canadian Rivers Institute, 10 Bailey Drive, PO Box 45111, University of New Brunswick, Fredericton E3B 6E1, New Brunswick (Canada); Nogueira, A.J.A. [Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Soares, A.M.V.M. [Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Riva, M.C. [Laboratory of Environmental Toxicology, Universitat Poltiecnica de Catalunya, CN 150 Km 14.5, Terrassa 08220 (Spain)

    2006-06-10

    Two different concepts, termed concentration addition (CA) and independent action (IA), describe general relationships between the effects of single substances and their corresponding mixtures allowing calculation of an expected mixture toxicity on the basis of known toxicities of the mixture components. Both concepts are limited to cases in which all substances in a mixture influence the same experimental endpoint, and are usually tested against a 'fixed ratio design' where the mixture ratio is kept constant throughout the studies and the overall concentration of the mixture is systematically varied. With this design, interaction among toxic components across different mixture ratios and endpoints (i.e. lethal versus sublethal) is not assessed. In this study lethal and sublethal (feeding) responses of Daphnia magna individuals to single and binary combinations of similarly and dissimilarly acting chemicals including the metals (cadmium, copper) and the pyrethroid insecticides ({lambda}-cyhalothrin and deltamethrin) were assayed using a composite experimental design to test for interactions among toxic components across mixture effect levels, mixture ratios, lethal and sublethal toxic effects. To account for inter-experiment response variability, in each binary mixture toxicity assay the toxicity of the individual mixture constituents was also assessed. Model adequacy was then evaluated comparing the slopes and elevations of predicted versus observed mixture toxicity curves with those estimated for the individual components. Model predictive abilities changed across endpoints. The IA concept was able to predict accurately mixture toxicities of dissimilarly acting chemicals for lethal responses, whereas the CA concept did so in three out of four pairings for feeding response, irrespective of the chemical mode of action. Interaction effects across mixture effect levels, evidenced by crossing slopes, were only observed for the binary mixture Cd and Cu for

  1. Toxicity of binary mixtures of metals and pyrethroid insecticides to Daphnia magna Straus. Implications for multi-substance risks assessment

    International Nuclear Information System (INIS)

    Barata, Carlos; Baird, D.J.; Nogueira, A.J.A.; Soares, A.M.V.M.; Riva, M.C.

    2006-01-01

    Two different concepts, termed concentration addition (CA) and independent action (IA), describe general relationships between the effects of single substances and their corresponding mixtures allowing calculation of an expected mixture toxicity on the basis of known toxicities of the mixture components. Both concepts are limited to cases in which all substances in a mixture influence the same experimental endpoint, and are usually tested against a 'fixed ratio design' where the mixture ratio is kept constant throughout the studies and the overall concentration of the mixture is systematically varied. With this design, interaction among toxic components across different mixture ratios and endpoints (i.e. lethal versus sublethal) is not assessed. In this study lethal and sublethal (feeding) responses of Daphnia magna individuals to single and binary combinations of similarly and dissimilarly acting chemicals including the metals (cadmium, copper) and the pyrethroid insecticides (λ-cyhalothrin and deltamethrin) were assayed using a composite experimental design to test for interactions among toxic components across mixture effect levels, mixture ratios, lethal and sublethal toxic effects. To account for inter-experiment response variability, in each binary mixture toxicity assay the toxicity of the individual mixture constituents was also assessed. Model adequacy was then evaluated comparing the slopes and elevations of predicted versus observed mixture toxicity curves with those estimated for the individual components. Model predictive abilities changed across endpoints. The IA concept was able to predict accurately mixture toxicities of dissimilarly acting chemicals for lethal responses, whereas the CA concept did so in three out of four pairings for feeding response, irrespective of the chemical mode of action. Interaction effects across mixture effect levels, evidenced by crossing slopes, were only observed for the binary mixture Cd and Cu for lethal effects

  2. Chemical behaviors of tritium formed in a LiF-BeF2 mixture and its removal from a molten mixture

    International Nuclear Information System (INIS)

    Oishi, J.; Moriyama, H.; Maeda, S.; Ohmura, T.; Moritani, K.

    1987-01-01

    Chemical behaviors of tritium formed in a LiF-BeF 2 mixture were studied using a radiometric method. Most of tritium was found to be present in the T + and T - states under no thermal treatment. The distribution of tritium in chemical states was explained by considering hot atom reactions and radiation chemical reactions. Tritium behaviors in a molten LiF-BeF 2 mixture were also studied at 873 K. In the presence of hydrogen, the isotopic exchange reaction which is TF + H 2 → HT + HF was observed to occur probably in the salt phase. The removal of tritium in a molten LiF-BeF 2 mixture was tried by sparging a gas in a melt for tritium purge, and the effects of the composition of purge gas and of the construction material of crucibles containing the melt on the removal rate were observed. (author)

  3. Quantiles for Finite Mixtures of Normal Distributions

    Science.gov (United States)

    Rahman, Mezbahur; Rahman, Rumanur; Pearson, Larry M.

    2006-01-01

    Quantiles for finite mixtures of normal distributions are computed. The difference between a linear combination of independent normal random variables and a linear combination of independent normal densities is emphasized. (Contains 3 tables and 1 figure.)

  4. Shear-induced phase changes in mixtures

    International Nuclear Information System (INIS)

    Romig, K.D.; Hanley, H.J.M.

    1986-01-01

    A thermodynamic theory to account for the behavior of liquid mixtures exposed to a shear is developed. One consequence of the theory is that shear-induced phase changes are predicted. The theory is based on a thermodynamics that includes specifically the shear rate in the formalism and is applied to mixtures by a straightforward modification of the corresponding states, conformalsolution approach. The approach is general but is used here for a mixture of Lennard-Jones particles with a Lennard-Jones equation of state as a reference fluid. The results are discussed in the context of the Scott and Van Konynenberg phase classification. It is shown that the influence of a shear does affect substantially the type of the phase behavior. Results from the model mixture are equated loosely with those from real polymeric liquids

  5. A simple approach to polymer mixture miscibility.

    Science.gov (United States)

    Higgins, Julia S; Lipson, Jane E G; White, Ronald P

    2010-03-13

    Polymeric mixtures are important materials, but the control and understanding of mixing behaviour poses problems. The original Flory-Huggins theoretical approach, using a lattice model to compute the statistical thermodynamics, provides the basic understanding of the thermodynamic processes involved but is deficient in describing most real systems, and has little or no predictive capability. We have developed an approach using a lattice integral equation theory, and in this paper we demonstrate that this not only describes well the literature data on polymer mixtures but allows new insights into the behaviour of polymers and their mixtures. The characteristic parameters obtained by fitting the data have been successfully shown to be transferable from one dataset to another, to be able to correctly predict behaviour outside the experimental range of the original data and to allow meaningful comparisons to be made between different polymer mixtures.

  6. Model structure selection in convolutive mixtures

    DEFF Research Database (Denmark)

    Dyrholm, Mads; Makeig, S.; Hansen, Lars Kai

    2006-01-01

    The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious represent......The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious...... representation in many practical mixtures. The new filter-CICAAR allows Bayesian model selection and can help answer questions like: ’Are we actually dealing with a convolutive mixture?’. We try to answer this question for EEG data....

  7. Modelling of an homogeneous equilibrium mixture model

    International Nuclear Information System (INIS)

    Bernard-Champmartin, A.; Poujade, O.; Mathiaud, J.; Mathiaud, J.; Ghidaglia, J.M.

    2014-01-01

    We present here a model for two phase flows which is simpler than the 6-equations models (with two densities, two velocities, two temperatures) but more accurate than the standard mixture models with 4 equations (with two densities, one velocity and one temperature). We are interested in the case when the two-phases have been interacting long enough for the drag force to be small but still not negligible. The so-called Homogeneous Equilibrium Mixture Model (HEM) that we present is dealing with both mixture and relative quantities, allowing in particular to follow both a mixture velocity and a relative velocity. This relative velocity is not tracked by a conservation law but by a closure law (drift relation), whose expression is related to the drag force terms of the two-phase flow. After the derivation of the model, a stability analysis and numerical experiments are presented. (authors)

  8. Viscosities of corium-concrete mixtures

    International Nuclear Information System (INIS)

    Seiler, J.M.; Ganzhorn, J.

    1997-01-01

    Severe accidents on nuclear reactors involve many situations such as pools of molten core material, melt spreading, melt/concrete interactions, etc. The word 'corium' designates mixtures of materials issued from the molten core at high temperature; these mixtures involve mainly: UO2, ZrO2, Zr and, in small amounts, Ni, Cr, Ag, In, Cd. These materials, when flowing out of the reactor vessel, may interact with the concrete of the reactor building thus introducing decomposition products of concrete into the original mixture. These decomposition products are mainly: SiO 2 , FeO, MgO, CaO and Al 2 O 3 in different amounts depending on the nature of the concrete being considered. Siliceous concrete is rich in SiO 2 , limestone concrete contains both SiO 2 and CaO. Liquidus temperatures of such mixtures are generally obove 2300 K whereas solidus temperatures are ∝1400 K. (orig.)

  9. Negative muon capture in noble gas mixtures

    International Nuclear Information System (INIS)

    Hutson, R.L.; Knight, J.D.; Leon, M.; Schillaci, M.E.; Knowles, H.B.; Reidy, J.J.

    1980-01-01

    We have determined the probabilities of atomic negative muon capture in binary mixtures of the gases He, Ne, Ar, and Kr at partial pressures near five atmospheres. Relative capture rates were deduced from measured muonic X-ray yields. (orig.)

  10. Mixture design procedure for flexible base.

    Science.gov (United States)

    2013-04-01

    This document provides information on mixture design requirements for a flexible base course. Sections : design requirements, job mix formula, contractor's responsibility, and engineer's responsibility. Tables : material requirements; requirements fo...

  11. Predicting skin permeability from complex chemical mixtures

    International Nuclear Information System (INIS)

    Riviere, Jim E.; Brooks, James D.

    2005-01-01

    Occupational and environmental exposure to topical chemicals is usually in the form of complex chemical mixtures, yet risk assessment is based on experimentally derived data from individual chemical exposures from a single, usually aqueous vehicle, or from computed physiochemical properties. We present an approach using hybrid quantitative structure permeation relationships (QSPeR) models where absorption through porcine skin flow-through diffusion cells is well predicted using a QSPeR model describing the individual penetrants, coupled with a mixture factor (MF) that accounts for physicochemical properties of the vehicle/mixture components. The baseline equation is log k p = c + mMF + aΣα 2 H + bΣβ 2 H + sπ 2 H + rR 2 + vV x where Σα 2 H is the hydrogen-bond donor acidity, Σβ 2 H is the hydrogen-bond acceptor basicity, π 2 H is the dipolarity/polarizability, R 2 represents the excess molar refractivity, and V x is the McGowan volume of the penetrants of interest; c, m, a, b, s, r, and v are strength coefficients coupling these descriptors to skin permeability (k p ) of 12 penetrants (atrazine, chlorpyrifos, ethylparathion, fenthion, methylparathion, nonylphenol, ρ-nitrophenol, pentachlorophenol, phenol, propazine, simazine, and triazine) in 24 mixtures. Mixtures consisted of full factorial combinations of vehicles (water, ethanol, propylene glycol) and additives (sodium lauryl sulfate, methyl nicotinate). An additional set of 4 penetrants (DEET, SDS, permethrin, ricinoleic acid) in different mixtures were included to assess applicability of this approach. This resulted in a dataset of 16 compounds administered in 344 treatment combinations. Across all exposures with no MF, R 2 for absorption was 0.62. With the MF, correlations increased up to 0.78. Parameters correlated to the MF include refractive index, polarizability and log (1/Henry's Law Constant) of the mixture components. These factors should not be considered final as the focus of these studies

  12. Comparative conductimetric studies of salicylic acid in methanol–water mixtures at 25 °C

    Directory of Open Access Journals (Sweden)

    Zahra Chaaraoui

    2017-05-01

    Full Text Available Conductivity data of salicylic acid in methanol–water mixtures were measured at 25 °C. The data were analyzed in two methods, the Hsia–Fuoss’s and Fuoss 78’s conductance equations and a comparison was made. The two methods concern the derivation of thermodynamic association constants and limiting molar conductivities for all solvent compositions. The limiting equivalent conductance decreases with the increase of methanol content in the binary mixtures over the whole range of the solvent composition, but the variation does not give a constant value of Walden product. The electrolytes were found to be practically completely associated in all studied solvent mixtures. The association constant of acid decreases with the increase in relative permittivity of the mixtures. The values of ionic coefficients of self diffusion and the ionic conductance at infinite solutions were estimated.

  13. On modeling of structured multiphase mixtures

    International Nuclear Information System (INIS)

    Dobran, F.

    1987-01-01

    The usual modeling of multiphase mixtures involves a set of conservation and balance equations of mass, momentum, energy and entropy (the basic set) constructed by an averaging procedure or postulated. The averaged models are constructed by averaging, over space or time segments, the local macroscopic field equations of each phase, whereas the postulated models are usually motivated by the single phase multicomponent mixture models. In both situations, the resulting equations yield superimposed continua models and are closed by the constitutive equations which place restrictions on the possible material response during the motion and phase change. In modeling the structured multiphase mixtures, the modeling of intrinsic motion of grains or particles is accomplished by adjoining to the basic set of field equations the additional balance equations, thereby placing restrictions on the motion of phases only within the imposed extrinsic and intrinsic sources. The use of the additional balance equations has been primarily advocated in the postulatory theories of multiphase mixtures and are usually derived through very special assumptions of the material deformation. Nevertheless, the resulting mixture models can predict a wide variety of complex phenomena such as the Mohr-Coulomb yield criterion in granular media, Rayleigh bubble equation, wave dispersion and dilatancy. Fundamental to the construction of structured models of multiphase mixtures are the problems pertaining to the existence and number of additional balance equations to model the structural characteristics of a mixture. Utilizing a volume averaging procedure it is possible not only to derive the basic set of field equation discussed above, but also a very general set of additional balance equations for modeling of structural properties of the mixture

  14. Muonium radicals in benzene-styrene mixtures

    International Nuclear Information System (INIS)

    Ng, B.W.; Stadlbauer, J.W.; Walker, D.C.

    1984-01-01

    Muonium radicals were observed through their μ + SR precession frequencies in high transverse magnetic fields in pure benzene, pure styrene and their mixtures, all as liquids at room temperature. In benzene-styrene mixtures, the radicals obtained in each pure liquid are both present, so no slow (10 -9 -10 -5 s) intermolecular exchange occurs; but strong selectivity was found with the formation of the radical from styrene being about eight-times more probable than the radical from benzene. (Auth.)

  15. Construction of a 21-Component Layered Mixture Experiment Design

    International Nuclear Information System (INIS)

    Piepel, Gregory F.; Cooley, Scott K.; Jones, Bradley

    2004-01-01

    This paper describes the solution to a unique and challenging mixture experiment design problem involving: (1) 19 and 21 components for two different parts of the design, (2) many single-component and multi-component constraints, (3) augmentation of existing data, (4) a layered design developed in stages, and (5) a no-candidate-point optimal design approach. The problem involved studying the liquidus temperature of spinel crystals as a function of nuclear waste glass composition. The statistical objective was to develop an experimental design by augmenting existing glasses with new nonradioactive and radioactive glasses chosen to cover the designated nonradioactive and radioactive experimental regions. The existing 144 glasses were expressed as 19-component nonradioactive compositions and then augmented with 40 new nonradioactive glasses. These included 8 glasses on the outer layer of the region, 27 glasses on an inner layer, 2 replicate glasses at the centroid, and one replicate each of three existing glasses. Then, the 144 + 40 = 184 glasses were expressed as 21-component radioactive compositions and augmented with 5 radioactive glasses. A D-optimal design algorithm was used to select the new outer layer, inner layer, and radioactive glasses. Several statistical software packages can generate D-optimal experimental designs, but nearly all require a set of candidate points (e.g., vertices) from which to select design points. The large number of components (19 or 21) and many constraints made it impossible to generate the huge number of vertices and other typical candidate points. JMP(R) was used to select design points without candidate points. JMP uses a coordinate-exchange algorithm modified for mixture experiments, which is discussed in the paper

  16. Study of decolorisation of binary dye mixture by response surface methodology.

    Science.gov (United States)

    Khamparia, Shraddha; Jaspal, Dipika

    2017-10-01

    Decolorisation of a complex mixture of two different classes of textile dyes Direct Red 81 (DR81) and Rhodamine B (RHB), simulating one of the most important condition in real textile effluent was investigated onto deoiled Argemone Mexicana seeds (A. Mexicana). The adsorption behaviour of DR81 and RHB dyes was simultaneously analyzed in the mixture using derivative spectrophotometric method. Central composite design (CCD) was employed for designing the experiments for this complex binary mixture where significance of important parameters and possible interactions were analyzed by response surface methodology (RSM). Maximum adsorption of DR81 and RHB by A. Mexicana was obtained at 53 °C after 63.33 min with 0.1 g of adsorbent and 8 × 10 -6  M DR81, 12 × 10 -6  M RHB with composite desirability of 0.99. The predicted values for percentage removal of dyes from the mixture were in good agreement with the experimental values with R 2 > 96% for both the dyes. CCD superimposed RSM confirmed that presence of different dyes in a solution created a competition for the adsorbent sites and hence interaction of dyes was one of the most important factor to be studied to simulate the real effluent. The adsorbent showed remarkable adsorption capacities for both the dyes in the mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Chlorination of uranium oxides in melts of alkali metal chlorides and their mixtures

    International Nuclear Information System (INIS)

    Vorobej, M.P.; Bevz, A.S.; Skiba, O.V.

    1978-01-01

    Chlorination of UO 2 , U 3 O 8 , and UO 3 in melts of chlorides of alkali metals and of their mixtures has been studied by thermogravimetric, X-ray phase, and spectrophotometric methods. The thermogravimetric method has been proposed for evaluating the state of uranylcation in the melt; the effect of the composition of the oxide being chlorinated and of the salt-solvent on the composition of the chlorination products has been studied. The effect of the composition of the chlorination products on the stoichiometry of the electrolytic uranium dioxide has been shown

  18. Using Big Data Analytics to Address Mixtures Exposure

    Science.gov (United States)

    The assessment of chemical mixtures is a complex issue for regulators and health scientists. We propose that assessing chemical co-occurrence patterns and prevalence rates is a relatively simple yet powerful approach in characterizing environmental mixtures and mixtures exposure...

  19. Phase equilibria for mixtures containing very many components. development and application of continuous thermodynamics for chemical process design

    International Nuclear Information System (INIS)

    Cotterman, R.L.; Bender, R.; Prausnitz, J.M.

    1984-01-01

    For some multicomponent mixtures, where detailed chemical analysis is not feasible, the compositio of the mixture may be described by a continuous distribution function of some convenient macroscopic property suc as normal boiling point or molecular weight. To attain a quantitative description of phase equilibria for such mixtures, this work has developed thermodynamic procedures for continuous systems; that procedure is called continuous thermodynamics. To illustrate, continuous thermodynamics is used to calculate dew points for natural-gas mixtures, solvent loss in a high-pressure absorber, and liquid-liquid phase equilibria in a polymer fractionation process. Continuous thermodynamics provides a rational method for calculating phase equilibria for those mixtures where complete chemical analysis is not available but where composition can be given by some statistical description. While continuous thermodynamics is only the logical limit of the well-known pseudo-component method, it is more efficient than that method because it is less arbitrary and it often requires less computer time

  20. Analysis of hydrogen-deuterium mixtures and of mixtures of heavy-water and light-water by means of a mass spectrometer

    International Nuclear Information System (INIS)

    Chenouard, J.; Gueron, J.; Roth, E.

    1951-07-01

    The differences between hydrogen and deuterium with respect to the capture of thermal neutrons (hydrogen = 0.31 barn; deuterium 0.00065 barn) explains the interest of detecting small variations of the isotopic composition of the heavy waters used in the Chatillon nuclear pile. The aim of this report is to describe and discuss the method used since more than a year for the dosimetry of heavy waters. After a recall of the principle of mass spectroscopy analysis of deuterium-hydrogen mixtures, the preciseness of the results is presented and the balancing method used for the determination of the isotopic composition of hydrogen-deuterium mixtures is explained in detail. Finally, a brief comparison of the preciseness of mass spectroscopy measurements with the analyses made with other methods is performed. Some calculations and the tables of results are presented in appendixes. (J.S.)

  1. Raising, Sustaining Productivity and Quality in Mixtures Imperata Cylindrica-Stylosanthes Guyanensis Pastures with Phosphorus Fertilization and Defoliation Management

    OpenAIRE

    Nohong, Budiman

    2016-01-01

    Phosphorus fertilization on crop mixtures Cogongrass-Stylo's very important for the development of root nodules, nitrogen fixation and improve the botanical composition Stylo to confront an aggressive Cogon grass. This study aims to improve the productivity and quality of crops mixtures Cogon grass-Stylo through fertilization and defoliation frequency. The study consisted of two factors . The first factor is the phosphorus fertilizer with a dose of 0 (P0 ) and 100 kg P2O/ha (P1 ). The second ...

  2. Comparison of compressive strength of paving block with a mixture of Sinabung ash and paving block with a mixture of lime

    Science.gov (United States)

    Hastuty, I. P.; Sembiringand Nursyamsi, I. S.

    2018-02-01

    Paving block is one of the material used as the top layer of road structure besides asphalt and concrete paving block is usually made of mixed material such as Portland cement or other adhesive material, water, and aggregate. People nowadays prefer paving block compared to other pavement such as concrete or asphalt. Their interest toward the use of paving block increase because paving block is an eco-friendly construction which is very useful in helping soil water conservation, can be done faster, has easier installation and maintenance, has a variety of shades that increase the aesthetic value, also costs cheaper than the other. Preparation of the specimens with a mixture of Sinabung ash and a mixture of Sinabung ash and lime are implemented with a mixture ratio of cement : sand : stone ash is 1: 2 : 3. The mixture is used as a substitute material by reducing the percentage amount of the weight of the cement with the composition ratio variation based on the comparative volume category of the paving block aggregate, i.e. 0%, 5%, 10%, 15%, 20%, and 25%. The result of this research shows that the maximum compressive strength value is 42.27 Mpa, it was obtained from a mixture of 10% lime with curing time 28 days. The maximum compressive strength value which is obtained from the mixture of sinabung ash is 41.60 Mpa, it was obtained from a mixture of 15% sinabung ash. From the use of these two materials, paving blocks produced are classified as paving blocks quality A and B (350 - 400 Mpa) in accordance to specification from SNI 03-0691-1996.

  3. A turbulence model in mixtures. First part: Statistical description of mixture

    International Nuclear Information System (INIS)

    Besnard, D.

    1987-03-01

    Classical theory of mixtures gives a model for molecular mixtures. This kind of model is based on a small gradient approximation for concentration, temperature, and pression. We present here a mixture model, allowing for large gradients in the flow. We also show that, with a local balance assumption between material diffusion and flow gradients evolution, we obtain a model similar to those mentioned above [fr

  4. Construction of a 21-Component Layered Mixture Experiment Design Using a New Mixture Coordinate-Exchange Algorithm

    International Nuclear Information System (INIS)

    Piepel, Gregory F.; Cooley, Scott K.; Jones, Bradley

    2005-01-01

    This paper describes the solution to a unique and challenging mixture experiment design problem involving: (1) 19 and 21 components for two different parts of the design, (2) many single-component and multi-component constraints, (3) augmentation of existing data, (4) a layered design developed in stages, and (5) a no-candidate-point optimal design approach. The problem involved studying the liquidus temperature of spinel crystals as a function of nuclear waste glass composition. The statistical objective was to develop an experimental design by augmenting existing glasses with new nonradioactive and radioactive glasses chosen to cover the designated nonradioactive and radioactive experimental regions. The existing 144 glasses were expressed as 19-component nonradioactive compositions and then augmented with 40 new nonradioactive glasses. These included 8 glasses on the outer layer of the region, 27 glasses on an inner layer, 2 replicate glasses at the centroid, and one replicate each of three existing glasses. Then, the 144 + 40 = 184 glasses were expressed as 21-component radioactive compositions, and augmented with 5 radioactive glasses. A D-optimal design algorithm was used to select the new outer layer, inner layer, and radioactive glasses. Several statistical software packages can generate D-optimal experimental designs, but nearly all of them require a set of candidate points (e.g., vertices) from which to select design points. The large number of components (19 or 21) and many constraints made it impossible to generate the huge number of vertices and other typical candidate points. JMP was used to select design points without candidate points. JMP uses a coordinate-exchange algorithm modified for mixture experiments, which is discussed and illustrated in the paper

  5. Secondary organic aerosol from VOC mixtures in an oxidation flow reactor

    Science.gov (United States)

    Ahlberg, Erik; Falk, John; Eriksson, Axel; Holst, Thomas; Brune, William H.; Kristensson, Adam; Roldin, Pontus; Svenningsson, Birgitta

    2017-07-01

    The atmospheric organic aerosol is a tremendously complex system in terms of chemical content. Models generally treat the mixtures as ideal, something which has been questioned owing to model-measurement discrepancies. We used an oxidation flow reactor to produce secondary organic aerosol (SOA) mixtures containing oxidation products of biogenic (α-pinene, myrcene and isoprene) and anthropogenic (m-xylene) volatile organic compounds (VOCs). The resulting volume concentration and chemical composition was measured using a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), respectively. The SOA mass yield of the mixtures was compared to a partitioning model constructed from single VOC experiments. The single VOC SOA mass yields with no wall-loss correction applied are comparable to previous experiments. In the mixtures containing myrcene a higher yield than expected was produced. We attribute this to an increased condensation sink, arising from myrcene producing a significantly higher number of nucleation particles compared to the other precursors. Isoprene did not produce much mass in single VOC experiments but contributed to the mass of the mixtures. The effect of high concentrations of isoprene on the OH exposure was found to be small, even at OH reactivities that previously have been reported to significantly suppress OH exposures in oxidation flow reactors. Furthermore, isoprene shifted the particle size distribution of mixtures towards larger sizes, which could be due to a change in oxidant dynamics inside the reactor.

  6. Experimental and predicted refractive index properties in ternary mixtures of associated liquids

    International Nuclear Information System (INIS)

    Sechenyh, Vitaliy V.; Legros, Jean-Claude; Shevtsova, Valentina

    2011-01-01

    Highlights: → Measurements of refractive indices of 200 different aqueous ternary mixtures have been performed for two wave lengths. → Refractive indices of the associated ternary mixtures can be modeled with a relative error of about 0.9. → Difference between experimental and calculated derivatives of refractive index with concentration is unsatisfactory large. - Abstract: Refractive indices of ternary mixtures formed by (water + ethanol + k-ethylene glycol) (when k is mono, di or tri) and (water + t-butanol + dimethyl sulfoxide) are presented over a wide range of mixture compositions. All measurements have been conducted at 298.15 K and atmospheric pressure using two light sources: one in the visible (λ = 670 nm) and the other in the infrared (λ = 925 nm) spectrum. The performance of several mixing rules that are commonly used in modeling optical constants are examined. We demonstrate that the refractive indices of the associated ternary mixtures can be modeled with a relative error of about 0.9% by using the thermodynamical properties of the pure components. The concentration derivatives of the refractive index are an important parameter, as they are required for different experimental techniques. These derivatives have been determined from the experimental data on refractive indices. However, applying mixing rules for calculation of the derivatives of the refractive indices with respect to concentrations does not provide satisfactory results in the case of ternary mixtures of associated liquids.

  7. Thermogravimetric analysis of the polymer acrylate-vinyl ether mixture cured by radiation

    International Nuclear Information System (INIS)

    Danu, Sugiarto

    1998-01-01

    An experiment on thermal stability of the polymer acrylate-vinyl ether mixture cured by radiation have been done using thermogravimetric analysis. Three kinds of acrylic oligomers i.e., epoxy acrylate, urethane acrylate, and polypropylene glycol diacrylate, and vinyl ether monomers i.e., triethylene glycol divinyl ether (DVE-3), 1,4-cyclohexane dimethanol divinyl ether (CHVE), and butanediol monovinyl ether (HBVE) were used in the experiment. Reaction was taken via radical and cationic polymerisation. In case of cationic polymerisation, diphenyliodonium hexafluorophosphate fotoinisiator was used in the formulation. Thermogravimetric analysis was conducted in a nitrogen atmosphere at a flow rate of 40 ml/minute with a constant heating rate 10 o C and evaluation range were done from 25 to 500 o C. The results of thermogravimetric analysis showed that acrylate and DVE-3 mixture produced the polymer films with higher thermal stability than the mixture of acrylate with CHVE or HBVE. The composition of acrylate-vinyl ether mixture and degree of unsaturation of vinyl ether monomers influenced the thermal stability of polymer. The mixture of epoxy acrylate-vinyl ether and polypropylene glycol diacrylate-vinyl ether have 1 initial decomposition temperature whereas the urethane acrylate-vinyl ether mixture has 2 initial decomposition temperatures. (authors)

  8. Estimation of value at risk and conditional value at risk using normal mixture distributions model

    Science.gov (United States)

    Kamaruzzaman, Zetty Ain; Isa, Zaidi

    2013-04-01

    Normal mixture distributions model has been successfully applied in financial time series analysis. In this paper, we estimate the return distribution, value at risk (VaR) and conditional value at risk (CVaR) for monthly and weekly rates of returns for FTSE Bursa Malaysia Kuala Lumpur Composite Index (FBMKLCI) from July 1990 until July 2010 using the two component univariate normal mixture distributions model. First, we present the application of normal mixture distributions model in empirical finance where we fit our real data. Second, we present the application of normal mixture distributions model in risk analysis where we apply the normal mixture distributions model to evaluate the value at risk (VaR) and conditional value at risk (CVaR) with model validation for both risk measures. The empirical results provide evidence that using the two components normal mixture distributions model can fit the data well and can perform better in estimating value at risk (VaR) and conditional value at risk (CVaR) where it can capture the stylized facts of non-normality and leptokurtosis in returns distribution.

  9. Investigation of the helium proportion influence on the Prandtl number value of gas mixtures

    Directory of Open Access Journals (Sweden)

    S. A. Burtsev

    2014-01-01

    Full Text Available The paper investigates an influence of helium fraction (light gases on the Prandtl number value for binary and more complex gas mixtures.It is shown that a low value of the Prandtl number (Pr-number results in decreasing a temperature recovery factor value and, respectively, in reducing a recovery temperature value on the wall (thermoinsulated wall temperature with the compressive gas flow bypassing it. This, in turn, allows us to increase efficiency of gasdynamic energy separation in Leontyev's tube.The paper conducts a numerical research of the influence of binary and more complex gas mixture composition on the Prandtl number value. It is shown that a mixture of two gases with small and large molecular weight allows us to produce a mixture with a lower value of the Prandtl number in comparison with the initial gases. Thus, the value of Prandtl number decreases by 1.5-3.2 times in comparison with values for pure components (the more a difference of molar mass of components, the stronger is a decrease.The technique to determine the Prandtl number value for mixtures of gases in the wide range of temperatures and pressure is developed. Its verification based on experimental data and results of numerical calculations of other authors is executed. It is shown that it allows correct calculation of binary and more complex mixtures of gasesFor the mixtures of inert gases it has been obtained that the minimum value of the Prandtl number is as follows: for helium - xenon mixtures (He-Xe makes 0.2-0.22, for helium - krypton mixtures (He-Kr – 0.3, for helium - argon mixes (He-Ar – 0.41.For helium mixture with carbon dioxide the minimum value of the Prandtl number makes about 0.4, for helium mixture with N2 nitrogen the minimum value of the Prandtl number is equal to 0.48, for helium-methane (CH4 - 0.5 and helium – oxygen (O2 – 0.46.This decrease is caused by the fact that the thermal capacity of mixture changes under the linear law in regard to the

  10. Ion mobilities in Xe/Ne and other rare-gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Piscitelli, D; Pitchford, L C [Centre de Physique des Plasmas et Applications de Toulouse (CPAT), UMR 5002 CNRS, 118 route de Narbonne, 31062 Toulouse (France); Phelps, A V [JILA, University of Colorado and National Institute of Technology, Boulder, Colorado (United States); Urquijo, J de [Centro de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Post Office Box 48-3, 62251, 80309-0440 Cuernavaca, Moreno (Mexico); Basurto, E [Departmento de Ciencias Basicas, Universidad Autonoma Metropolitana, 02200 Mexico Distrito Federal (Mexico)

    2003-10-01

    The ion mobility or drift velocity data important for modeling glow discharges in rare gas mixtures are not generally available, nor are the ion-neutral scattering cross sections needed to calculate these data. In this paper we propose a set of cross sections for Xe{sup +} and Ne{sup +} collisions with Xe and Ne atoms. Ion mobilities at 300 K calculated using this cross section set in a Monte Carlo simulation are reported for reduced field strengths, E/N, up to 1500x10{sup -21} V m{sup 2}, in pure gases and in Xe/Ne mixtures containing 5% and 20% Xe/Ne, which are mixtures of interest for plasma display panels (PDPs). The calculated Xe{sup +} mobilities depend strongly on the mixture composition, but the Ne{sup +} mobility varies only slightly with increasing Xe in the mixture over the range studied here. The mobilities in pure gases compare well with available experimental values, and mobilities in gas mixtures at low E/N compare well with our recent measurements which will be published separately. Results from these calculations of ion mobilities are used to evaluate the predictions of Blanc's law and of the mixture rule proposed by Mason and Hahn [Phys. Rev. A 5, 438 (1972)] for determining the ion mobilities in mixtures from a knowledge of the mobilities in each of the pure gases. The mixture rule of Mason and Hahn is accurate to better than 10% at high field strengths over a wide range of conditions of interest for modeling PDPs. We conclude that a good estimate of ion mobilities at high E/N in Xe/Ne and other binary rare gas mixtures can be obtained using this mixture rule combined with known values of mobilities in parent gases and with the Langevin form for mobility of rare gas ions ion in other gases. This conclusion is supported by results in Ar/Ne mixtures which are also presented here.

  11. Weed infestation of a cereal-legume mixture depending on its concentration and position in a crop rotation

    Directory of Open Access Journals (Sweden)

    Marta K. Kostrzewska

    2012-10-01

    Full Text Available A field study was carried out in the period 2000-2006 at the Experimental Station in Tomaszkowo belonging to the University of Warmia and Mazury in Olsztyn. Its aim was to compare weed infestation of a mixture of spring barley and field pea grown in a four crop rotation with different crop selection and sequence. Each year during tillering of spring barley and before the harvest of the mixture, weed species composition and density were evaluated, while additionally weed biomass was also estimated before the harvest. These results were used to determine species constancy, Simpson’s dominance index, the Shannon-Wiener diversity and evenness indices as well as the community similarity index based on floristic richness, numbers and biomass of particular weed species. The cropping frequency and the position of the mixture in the crop rotation did not differentiate the species composition and total biomass of weed communities in the cereal-legume mixture crops. The crop rotation in which the mixture constituted 50% and was grown after itself had a reducing effect on weed numbers. Growing field pea in the 4-year crop rotation promoted weed infestation of the mixture and the dominance of weed communities. Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Elymus repens, Polygonum convolvulus, and Sonchus arvensis were constant components of the agrophytocenoses. The weed communities were more similar in terms of their floristic composition than in terms of weed density and air-dry weight of weeds.

  12. Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures

    Science.gov (United States)

    Almandoz, M. C.; Sancho, M. I.; Blanco, S. E.

    2014-01-01

    The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π*). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture.

  13. Viscosities of binary mixtures of toluene with butan-1-ol and 2-methylpropan-2-ol

    Directory of Open Access Journals (Sweden)

    VASILE DUMITRESCU

    2005-11-01

    Full Text Available The viscosities of binary liquid mixtures of toluene with butan-1-ol and 2-methylpropan-2-ol have been determined at 298.15, 303.15, 308.15, 313.15 and 318.15 K over the whole concentration range. The Hind, Grunberg–Nissan, Wijk, Auslander and McAllister models were used to calculate the viscosity coefficients and these were compared with the experimental data for the mixtures. Excess viscosities were also calculated and fitted to the Redlich–Kister equation. Various thermodynamic properties of viscous flow activation were determined and their variations with composition are discussed.

  14. Radiation curing of mixtures of diallylphthalate prepolymer and vinyl monomer, 9

    International Nuclear Information System (INIS)

    Gotoda, Masao; Kitada, Yoshinori.

    1975-01-01

    Radiation curing, mainly by electron beams was studied with mixtures of low molecular weight diallylphthalate prepolymer (DAPsub(p).L) and vinyl monomers with special reference to their workability. Among the vinyl monomers, acrylonitrile gave a solution of low viscosity and methyl acrylate gave a solution of low dose curing. Radiation curing of DAPsub(p).L/vinyl monomer mixtures impregnated in wood was also tried. To obtain uniform wood-polymer composites, γ-irradiation after impregnation at 10 kg/cm 2 was found to be required for thick plate (110 mm), while electron beam irradiation after impregnation at normal pressure was sufficient for thin plate. (author)

  15. Saturated steams pressure of HfCl/sub 4/-KCl molten mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, A B; Smirnov, M V; Kudyakov, V Ya [AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii

    1980-02-01

    A bellows null pressure gauge and the dynamic method were used to measure the total and partial pressures of saturated vapors of individual components of molten HfCl/sub 4/-KCl mixtures, as a function of temperature (260 to 1000 deg C) and composition (1.9 to 64.3 mol.% HfCl/sub 4/). Empirical equations expressing the relationship between pressure and temperature are presented. It is shown that in molten mixtures of hafnium tetrachloride with chlorides of alkaline metals its partial pressure dramatically increases when potassium chloride substitutes for cesium chloride.

  16. Saturated steams pressure of HfCl4-KCl molten mixtures

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Smirnov, M.V.; Kudyakov, V.Ya.

    1980-01-01

    A bellows null pressure gauge and the dynamic method were used to measure the total and partial pressures of saturated vapors of individual components of molten HfCl 4 -KCl mixtures, as a function of temperature (260 to 1000 deg C) and composition (1.9 to 64.3 mol.% HfCl 4 ). Empirical equations expressing the relationship between pressure and temperature are presented. It is shown that in molten mixtures of hafnium tetrachloride with chlorides of alkaline metals its partial pressure dramatically increases when potassium chloride substitutes for cesium chloride

  17. Influence of special attributes of zeotropic refrigerant mixtures on design and operation of vapour compression refrigeration and heat pump systems

    International Nuclear Information System (INIS)

    Rajapaksha, Leelananda

    2007-01-01

    The use of zeotropic refrigerant mixtures introduces a number of novel issues that affect the established design and operational practices of vapour compression systems used in refrigeration, air conditioning and heat pump applications. Two attributes; composition shift and temperature glide, associated with the phase changing process of zeotropic mixtures are the primary phenomena that bring in these issues. However, relevant researches are uncovering ways how careful system designs and selection of operational parameters allow improving the energy efficiency and the capacity of vapour compression refrigeration systems. Most of these concepts exploit the presence of composition shift and temperature glide. This paper qualitatively discusses how the mixture attributes influence the established heat exchanger design practices, performance and operation of conventional vapour compression systems. How the temperature glide and composition shift can be incorporated to improve the system performance and the efficiency are also discussed

  18. The effect of heat exchanger parameters on performance predictions for nonazeotropic refrigerant mixtures in liquid-liquid heat pumps

    International Nuclear Information System (INIS)

    Stanger, S.; Den Braven, K.R.; Owre, T.A.S.

    1990-01-01

    The effects of constant heat exchanger area on the coefficient of performance (COP) for liquid-liquid heat pumps were analyzed for systems which use nonazeotropic mixtures as the working fluid. For this analysis, two different computer models were compared. In the first, the log mean temperature differences (LMTDs) through the heat exchangers were specified, and were held constant for all refrigerant compositions. The second method was constructed so that the heat exchanger UA product was held constant, thus approximating constant heat exchanger area over a range of refrigerant compositions. Results from these models show only a one percent difference in COP prediction between holding LMTD constant and holding UA constant over the range of mixture composition. This paper reports the models compared using mixtures of R-22/R-11 and R-22/R-114. It is also shown that changes in glide and lift temperatures have little influence on the differences between the two models

  19. Method and composition for removing iodine from gases

    International Nuclear Information System (INIS)

    French, J.A.; O'Hara, D.K.; Pasha, M.

    1980-01-01

    A method and composition for removing iodine and organic iodides from an iodine-containing off-gas stream is provided. The composition for the removal is a ceramic material impregnated with a mixture of a metallic salt with a water-soluble secondary amine. The method for removing the iodine and iodide is accomplished by passing the off-gas stream over the ceramic impregnated with the metallic salt-amine mixture

  20. Healable Composites

    Science.gov (United States)

    2012-03-28

    oriented fibers and healable polymer matrix 4. Laminate pre-preg layers to form composite panels with minimal voids & defects 5. Characterize the...composites: determine mechanical and crack healing properties (4, 5) Composite (3) Prepreg (2) Polymer (1) Furan (1) Maleimide Healable Composites...Develop pre-preg system of oriented fibers and healable polymer matrix 4. Laminate pre-preg layers to form composite panels with minimal voids & defects

  1. Plant fibre composites - porosity and stiffness

    DEFF Research Database (Denmark)

    Madsen, Bo; Thygesen, Anders; Lilholt, Hans

    2009-01-01

    Plant fibre composites contain typically a relatively large amount of porosity which influences their performance. A model, based on a modified rule of mixtures, is presented to include the influence of porosity on the composite stiffness. The model integrates the volumetric composition...... of the composites with their mechanical properties. The fibre weight fraction is used as an independent parameter to calculate the complete volumetric composition. A maximum obtainable stiffness of the composites is calculated at a certain transition fibre weight fraction, which is characterised by a best possible...... combination of high fibre volume fraction and low porosity. The model is validated with experimental data from the literature on several types of composites. A stiffness diagram is presented to demonstrate that the calculations can be used for tailoring and design of composites with a given profile...

  2. Iron aluminide composites

    International Nuclear Information System (INIS)

    Schneibel, J.H.

    1999-01-01

    Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB 2 , and ZrB 2 . In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructures, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength of elevated temperatures (1,073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a rule of mixtures. Interestingly, sufficiently thin (<1 microm) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminides, environmental embrittlement is dramatically reduced in iron aluminide composites

  3. Mixture toxicity revisited from a toxicogenomic perspective.

    Science.gov (United States)

    Altenburger, Rolf; Scholz, Stefan; Schmitt-Jansen, Mechthild; Busch, Wibke; Escher, Beate I

    2012-03-06

    The advent of new genomic techniques has raised expectations that central questions of mixture toxicology such as for mechanisms of low dose interactions can now be answered. This review provides an overview on experimental studies from the past decade that address diagnostic and/or mechanistic questions regarding the combined effects of chemical mixtures using toxicogenomic techniques. From 2002 to 2011, 41 studies were published with a focus on mixture toxicity assessment. Primarily multiplexed quantification of gene transcripts was performed, though metabolomic and proteomic analysis of joint exposures have also been undertaken. It is now standard to explicitly state criteria for selecting concentrations and provide insight into data transformation and statistical treatment with respect to minimizing sources of undue variability. Bioinformatic analysis of toxicogenomic data, by contrast, is still a field with diverse and rapidly evolving tools. The reported combined effect assessments are discussed in the light of established toxicological dose-response and mixture toxicity models. Receptor-based assays seem to be the most advanced toward establishing quantitative relationships between exposure and biological responses. Often transcriptomic responses are discussed based on the presence or absence of signals, where the interpretation may remain ambiguous due to methodological problems. The majority of mixture studies design their studies to compare the recorded mixture outcome against responses for individual components only. This stands in stark contrast to our existing understanding of joint biological activity at the levels of chemical target interactions and apical combined effects. By joining established mixture effect models with toxicokinetic and -dynamic thinking, we suggest a conceptual framework that may help to overcome the current limitation of providing mainly anecdotal evidence on mixture effects. To achieve this we suggest (i) to design studies to

  4. A constitutive theory of reacting electrolyte mixtures

    Science.gov (United States)

    Costa Reis, Martina; Wang, Yongqi; Bono Maurizio Sacchi Bassi, Adalberto

    2013-11-01

    A constitutive theory of reacting electrolyte mixtures is formulated. The intermolecular interactions among the constituents of the mixture are accounted for through additional freedom degrees to each constituent of the mixture. Balance equations for polar reacting continuum mixtures are accordingly formulated and a proper set of constitutive equations is derived with basis in the Müller-Liu formulation of the second law of thermodynamics. Moreover, the non-equilibrium and equilibrium responses of the reacting mixture are investigated in detail by emphasizing the inner and reactive structures of the medium. From the balance laws and constitutive relations, the effects of molecular structure of constituents upon the fluid flow are studied. It is also demonstrated that the local thermodynamic equilibrium state can be reached without imposing that the set of independent constitutive variables is time independent, neither spatially homogeneous nor null. The resulting constitutive relations presented throughout this work are of relevance to many practical applications, such as swelling of clays, developing of bio and polymeric membranes, and use of electrorheological fluids in industrial processes. The first author acknowledges financial support from National Counsel of Technological and Scientific Development (CNPq) and German Academic Exchange Service (DAAD).

  5. Yield and competition in barley variety mixtures

    Directory of Open Access Journals (Sweden)

    Kari Jokinen

    1991-09-01

    Full Text Available Competition between spring barley varieties and yield performance of two-, three and four-variety mixtures were studied in two replacement series field experiments. In the first experiment, repeated in three successive years (1983 —85 the components were the six-row varieties Agneta, Arra, Hja-673 and Porno. In the second experiment (1984, including two nitrogen doses (50 and 100 kgN/ha, both six-row (Agneta, Pomo and two-row (Ida, Kustaa varieties were used. Arra in the first and Agneta in the second experiment were the most competitive varieties. The results suggested that the fast growth of Arra at the beginning promoted its competitive ability. Increase in available nitrogen usually strengthened the competitiveness of Agneta. The observed competitive differences between varieties were not related to the earliness of a variety, neither to the morphological characters (two- and six-row varieties nor to the grain yield of a variety grown alone. The competitive ability was not always a stable character, the dominant suppression relationship varying from one environment to another (e.g. growing season, nitrogen dose. The observed overyielding was not statistically significant. The ratio of actual to expected yield and the relative yield total of several mixtures exceeded slightly one. As a conclusion, the yield advantage of mixtures was marginal. As a rule, the mixtures were not more stable than monocultures as determined by the coefficient of variation. However, the yield of some mixtures varied less than the yield of the most stable monoculture.

  6. Evaluation of Different Mineral Filler Aggregates for Asphalt Mixtures

    Science.gov (United States)

    Wasilewska, Marta; Małaszkiewicz, Dorota; Ignatiuk, Natalia

    2017-10-01

    Mineral filler aggregates play an important role in asphalt mixtures because they fill voids in paving mix and improve the cohesion of asphalt binder. Limestone powder containing over 90% of CaCO3 is the most frequently used type of filler. Waste material from the production of coarse aggregate can be successfully used as a mineral filler aggregate for hot asphalt concrete mixtures as the limestone powder replacement. This paper presents the experimental results of selected properties of filler aggregates which were obtained from rocks with different mineral composition and origin. Five types of rocks were used as a source of the mineral filler aggregate: granite, gabbro, trachybasalt, quartz sandstone and rocks from postglacial deposits. Limestone filler was used in this study as the reference material. The following tests were performed: grading (air jet sieving), quality of fines according to methylene blue test, water content by drying in a ventilated oven, particle density using pyknometer method, Delta ring and ball test, Bitumen Number, fineness determined as Blaine specific surface area. Mineral filler aggregates showed significant differences when they were mixed with bitumen and stiffening effect in Delta ring and ball test was evaluated. The highest values were achieved when gabbro and granite fillers were used. Additionally, Scanning Electron Microscopy (SEM) analysis of grain shape and size was carried out. Significant differences in grain size and shape were observed. The highest non-homogeneity in size was determined for quartz sandstone, gabbro and granite filler. Their Blaine specific surface area was lower than 2800 cm2/g, while for limestone and postglacial fillers with regular and round grains it exceeded 3000 cm2/g. All examined mineral filler aggregates met requirements of Polish National Specification WT-1: 2014 and could be used in asphalt mixtures.

  7. In vitro evaluation of oestrogenic/androgenic activity of the serum organochlorine pesticide mixtures previously described in a breast cancer case–control study

    International Nuclear Information System (INIS)

    Rivero, Javier; Luzardo, Octavio P.; Henríquez-Hernández, Luis A.; Machín, Rubén P.; Pestano, José; Zumbado, Manuel; Boada, Luis D.; Camacho, María; Valerón, Pilar F.

    2015-01-01

    Some organochlorine pesticides (OCs) have been individually linked to breast cancer (BC) because they exert oestrogenic effects on mammary cells. However, humans are environmentally exposed to more or less complex mixtures of these organochlorines, and the biological effects of these mixtures must be elucidated. In this work we evaluated the in vitro effects exerted on human BC cells by the OC mixtures that were most frequently detected in two groups of women who participated in a BC case–control study developed in Spain: healthy women and women diagnosed with BC. The cytotoxicity, oestrogenicity, and androgenicity of the most prevalent OC mixtures found in healthy women (H-mixture) and in BC patients (BC-mixture) were tested at concentrations that resembled those found in the serum of the evaluated women. Our results showed that both OC mixtures presented a similar oestrogenic activity and effect on cell viability, but BC-mixture showed an additional anti-androgenic effect. These results indicate that although the proliferative effect exerted by these mixtures on human breast cells seems to depend mainly on their oestrogenic action, the BC-mixture might additionally induce cell proliferation due to its anti-androgenic activity, therefore increasing the carcinogenic potential of this mixture. The findings of this study demonstrate that subtle variations in the composition of a mixture may induce relevant changes in its biological action. - Highlights: • E-screen and A-screen of two mixtures of organochlorine pesticides (OCP) • Assay concentrations based on a previous breast cancer case–control study • Only non-cytotoxic concentrations assayed • Both OCP mixtures induce proliferation mediated by oestrogen receptor. • OCP mixture of breast cancer patients exhibits additional androgenic activity.

  8. In vitro evaluation of oestrogenic/androgenic activity of the serum organochlorine pesticide mixtures previously described in a breast cancer case–control study

    Energy Technology Data Exchange (ETDEWEB)

    Rivero, Javier; Luzardo, Octavio P., E-mail: octavio.perez@ulpgc.es; Henríquez-Hernández, Luis A.; Machín, Rubén P.; Pestano, José; Zumbado, Manuel; Boada, Luis D.; Camacho, María; Valerón, Pilar F.

    2015-12-15

    Some organochlorine pesticides (OCs) have been individually linked to breast cancer (BC) because they exert oestrogenic effects on mammary cells. However, humans are environmentally exposed to more or less complex mixtures of these organochlorines, and the biological effects of these mixtures must be elucidated. In this work we evaluated the in vitro effects exerted on human BC cells by the OC mixtures that were most frequently detected in two groups of women who participated in a BC case–control study developed in Spain: healthy women and women diagnosed with BC. The cytotoxicity, oestrogenicity, and androgenicity of the most prevalent OC mixtures found in healthy women (H-mixture) and in BC patients (BC-mixture) were tested at concentrations that resembled those found in the serum of the evaluated women. Our results showed that both OC mixtures presented a similar oestrogenic activity and effect on cell viability, but BC-mixture showed an additional anti-androgenic effect. These results indicate that although the proliferative effect exerted by these mixtures on human breast cells seems to depend mainly on their oestrogenic action, the BC-mixture might additionally induce cell proliferation due to its anti-androgenic activity, therefore increasing the carcinogenic potential of this mixture. The findings of this study demonstrate that subtle variations in the composition of a mixture may induce relevant changes in its biological action. - Highlights: • E-screen and A-screen of two mixtures of organochlorine pesticides (OCP) • Assay concentrations based on a previous breast cancer case–control study • Only non-cytotoxic concentrations assayed • Both OCP mixtures induce proliferation mediated by oestrogen receptor. • OCP mixture of breast cancer patients exhibits additional androgenic activity.

  9. Robust high temperature composite and CO sensor made from such composite

    Science.gov (United States)

    Dutta, Prabir K.; Ramasamy, Ramamoorthy; Li, Xiaogan; Akbar, Sheikh A.

    2010-04-13

    Described herein is a composite exhibiting a change in electrical resistance proportional to the concentration of a reducing gas present in a gas mixture, detector and sensor devices comprising the composite, a method for making the composite and for making devices comprising the composite, and a process for detecting and measuring a reducing gas in an atmosphere. In particular, the reducing gas may be carbon monoxide and the composite may comprise rutile-phase TiO2 particles and platinum nanoclusters. The composite, upon exposure to a gas mixture containing CO in concentrations of up to 10,000 ppm, exhibits an electrical resistance proportional to the concentration of the CO present. The composite is useful for making sensitive, low drift, fast recovering detectors and sensors, and for measuring CO concentrations in a gas mixture present at levels from sub-ppm up to 10,000 ppm. The composites, and devices made from the composites, are stable and operable in a temperature range of from about 450.degree. C. to about 700.degree. C., such as may be found in a combustion chamber.

  10. Geotechnical Properties of Rubber Tires and Sediments Mixtures

    Directory of Open Access Journals (Sweden)

    H. Sellaf

    2014-04-01

    Full Text Available An experimental work was undertaken to study the effect of rubber tires on the geotechnical properties of a dredged sediment, using a mixing ratio of large size. For comparison, two types of soil were studied (dredged sediment from Fergoug dam and Tizi Tuff from the north west of Algeria. Taking into account the high compressibility and the low water absorption of the rubber tires, grain size analysis, density, Atterberg limits analysis, chemical composition, direct shear tests, loading-unloading tests, modified Proctor and CBR tests are performed on the two soils and their mixtures with different scrap tire rubber (10, 20, 25 and 50%. The results show that liquid limits and plastic indexes decrease with the scrap tire rubber content and that the decrease is more significant for soil with high plasticity. Cohesion also decreases with scrap tire rubber content when the internal friction angle is vacillating. Compression and recompression indexes increase gradually with the scrap tire rubber content and the variation for compression index is more significant for the two soils. Compaction characteristics and CBR values decrease with scrap tire rubber content. The CBR values for W=3% are important compared to those with W=5% excepted for mixture with (75% tuff and 25% scrap tire rubber. The results show that the scrap tire rubber can be used as a reinforcement material for dredged soil, but with a content that should not highly affect the compressibility.

  11. Designing of Synergistic Waste Mixtures for Multiphase Reactive Smelting

    Directory of Open Access Journals (Sweden)

    Vaso Manojlović

    2016-06-01

    Full Text Available Electric arc furnace (EAF dust, together with a mill scale and coke were smelted in a laboratory electric arc furnace. These metallurgical wastes consist of a many different phases and elements, making the reaction process complex. Thermo-chemical analysis of the reactions in metal, slag, and gas phases was done, and used for modeling of the mixture composition and energy consumption required for smelting. Modelling was performed with the software named RikiAlC. The crude ZnO, slag, and metal phase were analyzed using the atomic absorption spectrometry (AAS, the optical emission spectrometry with inductively coupled plasma (ICP-OES, the X-ray diffraction (XRD, the scanning electron microscopy (SEM equipped with energy dispersive spectrometry (EDS, and reflected and transmitted light microscopy. Also, in order to follow the behavior of this process the exhausted gases were monitored. The synergetic effects of the designed mixture may be recognized in minimizing energy consumption for the smelting process, improving the product yield efficiency, and reducing the negative environmental effects.

  12. Mixture preparation by cool flames for diesel-reforming technologies

    Science.gov (United States)

    Hartmann, L.; Lucka, K.; Köhne, H.

    The separation of the evaporation from the high-temperature reaction zone is crucial for the reforming process. Unfavorable mixtures of liquid fuels, water and air lead to degradation by local hot spots in the sensitive catalysts and formation of unwanted by-products in the reformer. Furthermore, the evaporator has to work with dynamic changes in the heat transfer, residence times and educt compositions. By using exothermal pre-reactions in the form of cool flames it is possible to realize a complete and residue-free evaporation of liquid hydrocarbon mixtures. The conditions whether cool flames can be stabilised or not is related to the heat release of the pre-reactions in comparison to the heat losses of the system. Examinations were conducted in a flow reactor at atmospheric pressure and changing residence times to investigate the conditions under which stable cool flame operation is possible and auto-ignition or quenching occurs. An energy balance of the evaporator should deliver the values of heat release by cool flames in comparison to the heat losses of the system. The cool flame evaporation is applied in the design of several diesel-reforming processes (thermal and catalytic partial oxidation, autothermal reforming) with different demands in the heat management and operation range (air ratio λ, steam-to-carbon ratio, SCR). The results are discussed at the end of this paper.

  13. Anomalous separation of homogeneous particle-fluid mixtures: Further observations

    Science.gov (United States)

    Husain, H. S.; Hussain, F.; Goldshtik, M.

    1995-11-01

    Previously, we reported the puzzling phenomenon of separation of components from an initially uniform mixture (air and smoke) in a rotating flow device (a cylindrical can with a rotating end disk). Here we summarize further studies of this phenomenon through experiments, analysis of particle forces, and direct numerical simulation (DNS). Separation of spherical polystyrene particles when immersed in water or pure alcohol lends further credence to the phenomenon. We have studied the dependence of the particle-free column size and its establishment time on particle size, particle concentration, disk and cylinder Reynolds numbers, and fluid composition. The evolution of passive markers in DNS shows segregation similar to that observed in experiments, supporting our kinematic separation hypothesis. However, kinematic action, though important, is inadequate to explain the ``antidiffusion'' phenomenon. Although estimates show that known particle forces cannot account for the particle separation, experimental results suggest the action of a yet unknown lift force whose effect is magnified kinematically in our apparatus. At high particle concentrations or when a small amount of solute (e.g. sugar, salt, or alcohol) is added to water polystyrene particle mixtures, the flow within the column becomes unstable and the particle-free column loses its axial symmetry; this unusual behavior is not yet clearly understood.

  14. High resolution conductometry for isotopic assay of deuterium in mixtures of heavy water and light water

    International Nuclear Information System (INIS)

    Ananthanarayanan, R.; Sahoo, P.; Murali, N.

    2014-01-01

    A PC based high resolution conductivity monitoring technique has been deployed for determination of isotopic purity of heavy water in samples containing heavy water and light water mixtures using pulsating sensor based conductivity monitoring instrument. The technique involves accurate determination of conductivities of a series of specially treated heavy water and light water mixtures of various compositions at a constant solution temperature. The shift in conductivity (Δκ), which is the difference between conductivities of composite mixture after and before the formation of a typical complex compound (boric acid–mannitol complex in this case), shows a smooth and reproducible decreasing trend with increase in percentage composition of heavy water. This relation, which is obtained by appropriate calibration, is used in the software program for direct display of isotopic purity of heavy water. The technique is examined for determination of percentage composition of heavy water in the entire range of concentration (0-100 %) with reasonable precision (relative standard deviation, RSD ≤1.5 %). About 1 mL of sample is required for each analysis and analysis is completed within a couple of minutes after pretreatment of sample. The accuracy in measurement is ≤1.75 %. (author)

  15. Thermophysical properties of energetic ionic liquids/nitric acid mixtures: insights from molecular dynamics simulations.

    Science.gov (United States)

    Hooper, Justin B; Smith, Grant D; Bedrov, Dmitry

    2013-09-14

    Molecular dynamics (MD) simulations of mixtures of the room temperature ionic liquids (ILs) 1-butyl-4-methyl imidazolium [BMIM]/dicyanoamide [DCA] and [BMIM][NO3(-)] with HNO3 have been performed utilizing the polarizable, quantum chemistry based APPLE&P(®) potential. Experimentally it has been observed that [BMIM][DCA] exhibits hypergolic behavior when mixed with HNO3 while [BMIM][NO3(-)] does not. The structural, thermodynamic, and transport properties of the IL/HNO3 mixtures have been determined from equilibrium MD simulations over the entire composition range (pure IL to pure HNO3) based on bulk simulations. Additional (non-equilibrium) simulations of the composition profile for IL/HNO3 interfaces as a function of time have been utilized to estimate the composition dependent mutual diffusion coefficients for the mixtures. The latter have been employed in continuum-level simulations in order to examine the nature (composition and width) of the IL/HNO3 interfaces on the millisecond time scale.

  16. Detonation engine fed by acetylene-oxygen mixture

    Science.gov (United States)

    Smirnov, N. N.; Betelin, V. B.; Nikitin, V. F.; Phylippov, Yu. G.; Koo, Jaye

    2014-11-01

    The advantages of a constant volume combustion cycle as compared to constant pressure combustion in terms of thermodynamic efficiency has focused the search for advanced propulsion on detonation engines. Detonation of acetylene mixed with oxygen in various proportions is studied using mathematical modeling. Simplified kinetics of acetylene burning includes 11 reactions with 9 components. Deflagration to detonation transition (DDT) is obtained in a cylindrical tube with a section of obstacles modeling a Shchelkin spiral; the DDT takes place in this section for a wide range of initial mixture compositions. A modified ka-omega turbulence model is used to simulate flame acceleration in the Shchelkin spiral section of the system. The results of numerical simulations were compared with experiments, which had been performed in the same size detonation chamber and turbulent spiral ring section, and with theoretical data on the Chapman-Jouguet detonation parameters.

  17. Role of calcium-enriched mixture in endodontics

    Directory of Open Access Journals (Sweden)

    Pradeep Kabbinale

    2015-01-01

    Full Text Available Calcium-enriched mixture (CEM has been recently introduced as a hydrophilic tooth-colored cement. The CEM cement powder is composed of calcium oxide, calcium sulfate, phosphorus oxide, and silica as major elements. CEM is alkaline cement (pH~11 that releases calcium hydroxide (CH during and after setting. The physical properties of CEM, such as flow, film thickness, and primary setting time are favorable. This cement is biocompatible and induces formation of cementum, dentin, bone and periodontal tissues. This novel cement has an antibacterial effect comparable to CH and superior to mineral trioxide aggregate (MTA and sealing ability similar to MTA. Its clinical applications include pulp capping, pulpotomy, root-end filling and perforation repair. This review describes the composition, properties and clinical applications of CEM in endodontics.

  18. DCMDN: Deep Convolutional Mixture Density Network

    Science.gov (United States)

    D'Isanto, Antonio; Polsterer, Kai Lars

    2017-09-01

    Deep Convolutional Mixture Density Network (DCMDN) estimates probabilistic photometric redshift directly from multi-band imaging data by combining a version of a deep convolutional network with a mixture density network. The estimates are expressed as Gaussian mixture models representing the probability density functions (PDFs) in the redshift space. In addition to the traditional scores, the continuous ranked probability score (CRPS) and the probability integral transform (PIT) are applied as performance criteria. DCMDN is able to predict redshift PDFs independently from the type of source, e.g. galaxies, quasars or stars and renders pre-classification of objects and feature extraction unnecessary; the method is extremely general and allows the solving of any kind of probabilistic regression problems based on imaging data, such as estimating metallicity or star formation rate in galaxies.

  19. The Viscosity of Organic Liquid Mixtures

    Science.gov (United States)

    Len, C. W.; Trusler, J. P. M.; Vesovic, V.; Wakeham, W. A.

    2006-01-01

    The paper reports measurements of the viscosity and density of two heavy hydrocarbon mixtures, Dutrex and Arab Light Flashed Distillate (ALFD), and of their mixtures with hydrogen. The measurements have been carried out with a vibrating-wire device over a range of temperatures from 399 to 547 K and at pressures up to 20 MPa. Measurements have also been carried out on systems in which hydrogen at different concentrations has been dissolved in the liquids. The measurements have an estimated uncertainty of ±5% for viscosity and ±2% for density and represent the first results on these prototypical heavy hydrocarbons. The results reveal that the addition of hydrogen reduces both the density and viscosity of the original hydrocarbon mixture at a particular temperature and pressure.

  20. Capillary condensation and adsorption of binary mixtures.

    Science.gov (United States)

    Weinberger, B; Darkrim-Lamari, F; Levesque, D

    2006-06-21

    The adsorption of equimolar binary mixtures of hydrogen-carbon dioxide, hydrogen-methane, and methane-carbon dioxide in porous material models is determined by grand canonical Monte Carlo simulations. The material models have an adsorbent surface similar to that of nanofibers with a herringbone structure. Our main result, which is relevant for hydrogen purification and carbon dioxide capture, is that the adsorption selectivities calculated for the mixtures can differ significantly from those deduced from simulations of the adsorption of pure gases, in particular, when one of the adsorbed gases presents a capillary condensation induced by confinement within the pore network. A comparison of our data is also made with theoretical models used in the literature for predicting the properties of the mixture adsorption.

  1. MICROBIAL QUALITY OF HONEY MIXTURE WITH POLLEN

    Directory of Open Access Journals (Sweden)

    Ján Mareček

    2011-02-01

    Full Text Available Normal 0 21 MicrosoftInternetExplorer4 The aim of this study was evaluation of microbial quality in raw materials (honey, pollen and evaluation of microbial quality in honey mixture with pollen (2.91 % and 3.85 % and also dynamics of microbial groups in honey mixtures with pollen after 14 days storage at the room temperature (approximately 25 °C and in cold store (8 °C. We used dilution plating method for testing of samples. Detections of total plate microbial count (aerobic and anaerobic microorganisms, sporulating bacteria, coliform bacteria, Bifidobacterium sp., Lactobacillus sp. and microscopic fungi were performed. In general, counts of microorganisms decreased in honey mixture with pollen compared to raw pollen and these counts increased compared to natural honey. Total plate count was 5.37 log KTJ.g-1 in pollen; 1.36 log KTJ.g-1 in honey; 2.97 log KTJ.g-1 in honey mixture with 2.91 % pollen and 2.04 log KTJ.g-1 in honey mixture with 3.85 % pollen. Coliform bacteria were detected in pollen (1.77 log KTJ.g-1. Then, we found coliform bacteria in one sample of honey mixtures with pollen (2.91 % - 1.00 log KTJ.g-1.Bifidobacterium species were detected only in raw pollen. We did not findLactobacillus sp. in any of the samples. Microscopic fungi were detected on two cultivating media. Yeasts were present in pollen sample (average 5.39 log KTJ.g-1, honey mixture with 2.91 % pollen (average 2.51 log KTJ.g-1 and honey mixture with 3.85 % pollen (average 1.58 log KTJ.g-1. Filamentous microscopic fungi were detectable in pollen (average 3.38 log KTJ.g-1, in honey (only on one medium: 1.00 log KTJ.g-1, in honey mixture with 2.91 % pollen (average 1.15 log KTJ.g-1 and in honey mixture with 3.85 % pollen (1.71 %. Raw pollen contained microscopic fungi as Absidiasp., Mucor sp., Alternaria sp. andEmericella nidulans. Honey mixture with 2.91 % pollen after storage (14 days contained lower microbial counts when compared with the sample

  2. Excess Volumes and Excess Isentropic Compressibilities of Binary Liquid Mixtures of Trichloroethylene with Esters at 303.15 K

    Science.gov (United States)

    Ramanaiah, S.; Rao, C. Narasimha; Nagaraja, P.; Venkateswarlu, P.

    2015-11-01

    Exces volumes, VE, and excess isentropic compressibilities, κSE, have been reported as a function of composition for binary liquid mixtures of trichloroethylene with ethyl acetate, n-propyl acetate, and n-butyl acetate at 303.15 K. Isentropic compressibilities are calculated using measured sound speeds and density data for pure components and for binary mixtures. Excess volumes and excess isentropic compressibilities are found to be negative for the three systems studied over the entire composition range at 303.15 K, whereas these values become more negative with an increase of carbon chain length. The results are discussed in terms of intermolecular interactions between unlike molecules.

  3. Flows and chemical reactions in homogeneous mixtures

    CERN Document Server

    Prud'homme, Roger

    2013-01-01

    Flows with chemical reactions can occur in various fields such as combustion, process engineering, aeronautics, the atmospheric environment and aquatics. The examples of application chosen in this book mainly concern homogeneous reactive mixtures that can occur in propellers within the fields of process engineering and combustion: - propagation of sound and monodimensional flows in nozzles, which may include disequilibria of the internal modes of the energy of molecules; - ideal chemical reactors, stabilization of their steady operation points in the homogeneous case of a perfect mixture and c

  4. in Binary Liquid Mixtures of Ethyl benzoate

    Directory of Open Access Journals (Sweden)

    Shaik Babu

    2012-01-01

    Full Text Available Ultrasonic velocity is measured at 2MHz frequency in the binary mixtures of Ethyl Benzoate with 1-Propanol, 1-Butanol, 1-Pentanol and theoretical values of ultrasonic velocity have been evaluated at 303K using Nomoto's relation, Impedance relation, Ideal mixture relation, Junjie's method and free length theory. Theoretical values are compared with the experimental values and the validity of the theories is checked by applying the chi-square test for goodness of fit and by calculating the average percentage error (APE. A good agreement has been found between experimental and Nomoto’s ultrasonic velocity.

  5. Robust classification using mixtures of dependency networks

    DEFF Research Database (Denmark)

    Gámez, José A.; Mateo, Juan L.; Nielsen, Thomas Dyhre

    2008-01-01

    Dependency networks have previously been proposed as alternatives to e.g. Bayesian networks by supporting fast algorithms for automatic learning. Recently dependency networks have also been proposed as classification models, but as with e.g. general probabilistic inference, the reported speed......-ups are often obtained at the expense of accuracy. In this paper we try to address this issue through the use of mixtures of dependency networks. To reduce learning time and improve robustness when dealing with data sparse classes, we outline methods for reusing calculations across mixture components. Finally...

  6. Plasma assisted combustion of parafin mixture

    International Nuclear Information System (INIS)

    Nedybaliuk, O.A.; Chernyak, V.Ya.; Martysh, E.V.; Lisitchenko, T.E.; Vergun, O.Yu.; Orlovska, S.G.

    2013-01-01

    In this work the results of solid paraffin combustion with the aid of the plasma of transverse and rotational gliding arc studies are represented. The question of the additional activation of paraffin based solid fuels is examined. The mixture of n-paraffin and stearin in the solid state as the model of the solid paraffin based fuel is used. The plasma assisted combustion of this model is experimentally investigated. The voltage-current characteristics of discharge at the different regimes are measured. The population temperatures of excited rotational levels are determined. The flame temperature during the combustion of solid paraffin containing mixture is calculated

  7. Separation of alcohols from organic liquid mixtures by pervaporation

    NARCIS (Netherlands)

    Park, Hyun-Chae

    1993-01-01

    In the chemical industry, distillation is generally the preferred technique to separate a liquid mixture. However some liquid mixtures such as azeotropic mixtures, close-boiling hydrocarbons, and various isomers are difficult to separate by simple distillation. For the separation of these mixtures

  8. Composite Material from By-products and Its Properties

    Science.gov (United States)

    Šeps, K.; Broukalová, I.; Vodička, J.

    2017-09-01

    The paper shows an example of utilization of specific textile admixture - fluffs of torn textiles from waste cars in production of composite with aggregate consisting entirely of unsorted recycled concrete. The admixture in the mixture of recycled concrete and cement binder fills the pores and voids in composite. The elaborated composite has working title STEREDconcrete. In the article, basic mechanical-physical properties of the composite are presented also the fire resistance of STEREDconcrete, which was determined in tests.

  9. Influence of irradiation on electrical properties of cermet composition

    International Nuclear Information System (INIS)

    Iskhakov, V.M.; Avanesyan, R.R.; Daukeev, D.K.; Nedorezov, V.G.; Chormonov, N.T.; Chormonov, T.Kh.; Shevelev, G.A.

    1986-01-01

    Cermet composition radiation stability and also possibility of directed change of the composition properties during radiation treatment were studied. Investigations were carried out using cermet composition containing 40 mass % of conducting phase (RuO 2 +Nb 2 O 5 additions) and 60 mass % of alumoborosilicate glass. Composition and organic binder mixture was applied to a dielectric substrate with land by stenciling, then was calcinated in the travelling furnace at 850 deg C for 15 min

  10. Gas-particle partitioning of semivolatile organic compounds (SOCs) on mixtures of aerosols in a smog chamber.

    Science.gov (United States)

    Chandramouli, Bharadwaj; Jang, Myoseon; Kamens, Richard M

    2003-09-15

    The partitioning behavior of a set of diverse SOCs on two and three component mixtures of aerosols from different sources was studied using smog chamber experimental data. A set of SOCs of different compound types was introduced into a system containing a mixture of aerosols from two or more sources. Gas and particle samples were taken using a filter-filter-denuder sampling system, and a partitioning coefficient Kp was estimated using Kp = Cp/(CgTSP). Particle size distributions were measured using a differential mobility analyzer and a light scattering detector. Gas and particle samples were analyzed using GCMS. The aerosol composition in the chamber was tracked chemically using a combination of signature compounds and the organic matter mass fraction (f(om)) of the individual aerosol sources. The physical nature of the aerosol mixture in the chamber was determined using particle size distributions, and an aggregate Kp was estimated from theoretically calculated Kp on the individual sources. Model fits for Kp showed that when the mixture involved primary sources of aerosol, the aggregate Kp of the mixture could be successfully modeled as an external mixture of the Kp on the individual aerosols. There were significant differences observed for some SOCs between modeling the system as an external and as an internal mixture. However, when one of the aerosol sources was secondary, the aggregate model Kp required incorporation of the secondary aerosol products on the preexisting aerosol for adequate model fits. Modeling such a system as an external mixture grossly overpredicted the Kp of alkanes in the mixture. Indirect evidence of heterogeneous, acid-catalyzed reactions in the particle phase was also seen, leading to a significant increase in the polarity of the resulting aerosol mix and a resulting decrease in the observed Kp of alkanes in the chamber. The model was partly consistent with this decrease but could not completely explain the reduction in Kp because of

  11. Effect of monomer composition on the properties of high temperature polymer concretes

    Energy Technology Data Exchange (ETDEWEB)

    Zeldin, A.; Kukacka, L.E.; Carciello, N.

    1980-01-01

    The effects of organic monomer composition on the thermomechanical properties of polymer concrete (PC) containing sand-cement mixtures as an agregate filler were investigated. The effects of various monomer mixtures on compressive strength and hydrolytic stability are discussed. Composites were fabricated in the same way as ordinary concrete, with monomer solutions of various compositions and concentrations used to bind the sand-cement mixture. The compressive strengths of th composites before and after exposure to air and to brine solutions at 240/sup 0/C are discussed.

  12. Gassmann Modeling of Acoustic Properties of Sand-clay Mixtures

    Science.gov (United States)

    Gurevich, B.; Carcione, J. M.

    The feasibility of modeling elastic properties of a fluid-saturated sand-clay mixture rock is analyzed by assuming that the rock is composed of macroscopic regions of sand and clay. The elastic properties of such a composite rock are computed using two alternative schemes.The first scheme, which we call the composite Gassmann (CG) scheme, uses Gassmann equations to compute elastic moduli of the saturated sand and clay from their respective dry moduli. The effective elastic moduli of the fluid-saturated composite rock are then computed by applying one of the mixing laws commonly used to estimate elastic properties of composite materials.In the second scheme which we call the Berryman-Milton scheme, the elastic moduli of the dry composite rock matrix are computed from the moduli of dry sand and clay matrices using the same composite mixing law used in the first scheme. Next, the saturated composite rock moduli are computed using the equations of Brown and Korringa, which, together with the expressions for the coefficients derived by Berryman and Milton, provide an extension of Gassmann equations to rocks with a heterogeneous solid matrix.For both schemes, the moduli of the dry homogeneous sand and clay matrices are assumed to obey the Krief's velocity-porosity relationship. As a mixing law we use the self-consistent coherent potential approximation proposed by Berryman.The calculated dependence of compressional and shear velocities on porosity and clay content for a given set of parameters using the two schemes depends on the distribution of total porosity between the sand and clay regions. If the distribution of total porosity between sand and clay is relatively uniform, the predictions of the two schemes in the porosity range up to 0.3 are very similar to each other. For higher porosities and medium-to-large clay content the elastic moduli predicted by CG scheme are significantly higher than those predicted by the BM scheme.This difference is explained by the fact

  13. The effect of water on thermal stresses in polymer composites

    Science.gov (United States)

    Sullivan, Roy M.

    1994-01-01

    The fundamentals of the thermodynamic theory of mixtures and continuum thermochemistry are reviewed for a mixture of condensed water and polymer. A specific mixture which is mechanically elastic with temperature and water concentration gradients present is considered. An expression for the partial pressure of water in the mixture is obtained based on certain assumptions regarding the thermodynamic state of the water in the mixture. Along with a simple diffusion equation, this partial pressure expression may be used to simulate the thermostructural behavior of polymer composite materials due to water in the free volumes of the polymer. These equations are applied to a specific polymer composite material during isothermal heating conditions. The thermal stresses obtained by the application of the theory are compared to measured results to verify the accuracy of the approach.

  14. Dynamic viscosity versus probe-reported microviscosity of aqueous mixtures of poly(ethylene glycol)

    International Nuclear Information System (INIS)

    Bhanot, Chhavi; Trivedi, Shruti; Gupta, Arti; Pandey, Shubha; Pandey, Siddharth

    2012-01-01

    Highlights: ► Aqueous polymer mixtures, non-toxic media of huge industrial importance, are investigated. ► Bulk viscosity of aqueous. PEG mixtures is shown to vary widely with composition and temperature. ► T-dependent viscosity follows Arrhenius behavior suggesting aqueous PEGs to be Newtonian fluids. ► Microviscosity sensed by a fluorescence ratiometric probe is estimated and correlated with viscosity. ► Microviscosity correlates well with bulk viscosity at higher PEG concentrations. - Abstract: Correlation between the dynamic viscosity (η) and the microviscosity of a hybrid green medium constituted of water and poly(ethylene glycol) (PEG) of average molar mass (200, 400, and 600) g · mol −1 , respectively, is explored over the temperatures range (10 to 90) °C across the complete composition regime. The microviscosity is obtained using a fluorescence probe 1,3-bis-(1-pyrenyl)propane (BPP), which is manifested through the ratio of the monomer-to-intramolecular excimer intensities (I M /I E ). Aqueous PEG mixtures are observed to behave similar to Newtonian fluids as the temperature dependence of dynamic viscosity follows Arrhenius-type behavior. Surprisingly, a simple and convenient linear dependence of ln η with wt% PEG of the mixture is established. The BPP I M /I E is observed, in general, to increase with the bulk dynamic viscosity of the mixture having >10 wt% PEG suggesting a good correlation between the bulk dynamic viscosity and BPP-reported microviscosity when the viscosity of the aqueous PEG mixture is relatively high.

  15. A combined experimental and computational investigation of excess molar enthalpies of (nitrobenzene + alkanol) mixtures

    International Nuclear Information System (INIS)

    Neyband, Razieh Sadat; Zarei, Hosseinali

    2015-01-01

    Highlights: • Excess molar enthalpies for the binary mixtures of nitrobenzene + alkanols mixtures were measured. • The infinite dilution excess partial molar enthalpies were calculated using the ab initio methods. • The PCM calculations were performed. • The computed excess partial molar enthalpies at infinite dilution were compared to experimental results. - Abstract: Excess molar enthalpies (H m E ) for the binary mixtures of {(nitrobenzene + ethanol), 1-propanol, 2-propanol, 1-butanol and 2-butanol} have been measured over the entire composition range at ambient pressure (81.5 kPa) and temperature 298 K using a Parr 1455 solution calorimeter. From the experimental results, the excess partial molar enthalpies (H i E ) and excess partial molar enthalpies at infinite dilution (H i E,∞ ) were calculated. The excess molar enthalpies (H m E ) are positive for all {nitrobenzene (1) + alkanol (2)} mixtures over the entire composition range. A state-of-the-art computational strategy for the evaluation of excess partial molar enthalpies at infinite dilution was followed at the M05-2X/6-311++G ∗∗ level of theory with the PCM model. The experimental excess partial molar enthalpies at infinite dilution have been compared to the computational data of the ab initio in liquid phase. Integrated experimental and computational results help to clarify the nature of the intermolecular interactions in {nitrobenzene (1) + alkanol (2)} mixtures. The experimental and computational work which was done in this study complements and extends the general research on the computation of excess partial molar enthalpy at infinite dilution of binary mixtures

  16. Densities and viscosities of binary and ternary mixtures of cyclohexanone, 1,4-dioxane and isooctane from T = (288.15 to 313.15) K

    International Nuclear Information System (INIS)

    Rafiee, Hamid Reza; Ranjbar, Shahram; Poursalman, Fariborz

    2012-01-01

    Graphical abstract: For binary and ternary mixtures of the following liquids the densities and viscosities have been determined at several temperatures and over the entire range of composition. Also the Δη and excess molar volumes for binary mixtures determined and have been fitted to the Redlich–Kister equation. The interaction parameters, G 12 in the Grunberg–Nissan equation have been found to be negative for all binary mixtures which indicates decreasing the interaction between unlike molecules. Highlights: ► Experimental data for viscosity and density of binary and ternary mixtures reported. ► The considered solvents are Cyclohexanone, 1,4-Dioxane and Isooctane. ► Temperature ranges from 288.15 to 313.15 K and entire range of composition is considered. ► G 12 , in Grunberg–Nissan equation was negative in all binary mixtures at all temperatures. ► V E and Δη for binary mixtures have been fitted to Redlich–Kister equation. - Abstract: Densities and viscosities of binary and ternary mixtures of cyclohexanone, 1,4-dioxane and isooctane have been measured at temperatures from 288.15 K to 313.15 K and over the entire composition range, under atmospheric pressure. From these binary data, the excess molar volumes have been determined and then fitted to Redlich–Kister equation to determine the appropriate coefficients. This work also provides a test of the Grunberg and Nissan equation for correlation the dynamic viscosities of binary mixtures with mole fractions. The interaction parameters for this equation, G 12 were negative for all binary mixtures at different temperatures over entire range of composition which attributed to decreasing the strength of interaction between unlike molecules in mixture.

  17. Challenges in modelling the random structure correctly in growth mixture models and the impact this has on model mixtures.

    Science.gov (United States)

    Gilthorpe, M S; Dahly, D L; Tu, Y K; Kubzansky, L D; Goodman, E

    2014-06-01

    Lifecourse trajectories of clinical or anthropological attributes are useful for identifying how our early-life experiences influence later-life morbidity and mortality. Researchers often use growth mixture models (GMMs) to estimate such phenomena. It is common to place constrains on the random part of the GMM to improve parsimony or to aid convergence, but this can lead to an autoregressive structure that distorts the nature of the mixtures and subsequent model interpretation. This is especially true if changes in the outcome within individuals are gradual compared with the magnitude of differences between individuals. This is not widely appreciated, nor is its impact well understood. Using repeat measures of body mass index (BMI) for 1528 US adolescents, we estimated GMMs that required variance-covariance constraints to attain convergence. We contrasted constrained models with and without an autocorrelation structure to assess the impact this had on the ideal number of latent classes, their size and composition. We also contrasted model options using simulations. When the GMM variance-covariance structure was constrained, a within-class autocorrelation structure emerged. When not modelled explicitly, this led to poorer model fit and models that differed substantially in the ideal number of latent classes, as well as class size and composition. Failure to carefully consider the random structure of data within a GMM framework may lead to erroneous model inferences, especially for outcomes with greater within-person than between-person homogeneity, such as BMI. It is crucial to reflect on the underlying data generation processes when building such models.

  18. Wood composites

    Science.gov (United States)

    Lars Berglund; Roger M. Rowell

    2005-01-01

    A composite can be defined as two or more elements held together by a matrix. By this definition, what we call “solid wood” is a composite. Solid wood is a three-dimensional composite composed of cellulose, hemicelluloses and lignin (with smaller amounts of inorganics and extractives), held together by a lignin matrix. The advantages of developing wood composites are (...

  19. MixtureTree annotator: a program for automatic colorization and visual annotation of MixtureTree.

    Directory of Open Access Journals (Sweden)

    Shu-Chuan Chen

    Full Text Available The MixtureTree Annotator, written in JAVA, allows the user to automatically color any phylogenetic tree in Newick format generated from any phylogeny reconstruction program and output the Nexus file. By providing the ability to automatically color the tree by sequence name, the MixtureTree Annotator provides a unique advantage over any other programs which perform a similar function. In addition, the MixtureTree Annotator is the only package that can efficiently annotate the output produced by MixtureTree with mutation information and coalescent time information. In order to visualize the resulting output file, a modified version of FigTree is used. Certain popular methods, which lack good built-in visualization tools, for example, MEGA, Mesquite, PHY-FI, TreeView, treeGraph and Geneious, may give results with human errors due to either manually adding colors to each node or with other limitations, for example only using color based on a number, such as branch length, or by taxonomy. In addition to allowing the user to automatically color any given Newick tree by sequence name, the MixtureTree Annotator is the only method that allows the user to automatically annotate the resulting tree created by the MixtureTree program. The MixtureTree Annotator is fast and easy-to-use, while still allowing the user full control over the coloring and annotating process.

  20. Toxicology of chemical mixtures: International perspective

    NARCIS (Netherlands)

    Feron, V.J.; Cassee, F.R.; Groten, J.P.

    1998-01-01

    This paper reviews major activities outside the United States on human health issues related to chemical mixtures. In Europe an international study group on combination effects has been formed and has started by defining synergism and antagonism. Successful research programs in Europe include the

  1. Collective dynamics in dense fluid mixtures

    International Nuclear Information System (INIS)

    Sinha, S.

    1992-01-01

    This thesis deals with the short wavelength collective dynamics of dense binary fluid mixtures. The analysis shows that at the level of linearized generalized hydrodynamics, the longitudinal modes of the system separates essentially into two parts - one involves the coupling of partial density fluctuations of the two species and the other involves coupling of longitudinal momentum and temperature fluctuations. The authors have shown that the coupling of longitudinal momentum and temperature fluctuations leads to an adequate description of sound propagation in such systems. In particular, they show that structural disorder controls the trapping of sound waves in dense mixtures. The coupling of the partial density fluctuations of the two species leads to a simple description of the partial dynamic structure factors. The results are in agreement with the molecular dynamics simulations of soft sphere mixtures. The partial density fluctuations are the slowest decaying fluctuations on molecular length scales and it turns out that nonlinear coupling of these slow modes leads to important corrections to the long time behavior of the time correlation functions determining the shear viscosity in dense mixtures

  2. The Coffee-Milk Mixture Problem Revisited

    Science.gov (United States)

    Marion, Charles F.

    2015-01-01

    This analysis of a problem that is frequently posed at professional development workshops, in print, and on the Web--the coffee-milk mixture riddle--illustrates the timeless advice of George Pólya's masterpiece on problem solving in mathematics, "How to Solve It." In his book, Pólya recommends that problems previously solved and put…

  3. Modelling interactions in grass-clover mixtures

    NARCIS (Netherlands)

    Nassiri Mahallati, M.

    1998-01-01

    The study described in this thesis focuses on a quantitative understanding of the complex interactions in binary mixtures of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) under cutting. The first part of the study describes the dynamics of growth, production

  4. Predicting diffusivities in dense fluid mixtures

    Directory of Open Access Journals (Sweden)

    C. DARIVA

    1999-09-01

    Full Text Available In this work the Enskog solution of the Boltzmann equation, as corrected by Speedy, together with the Weeks-Chandler-Andersen (WCA perturbation theory of liquids is employed in correlating and predicting self-diffusivities of dense fluids. Afterwards this theory is used to estimate mutual diffusion coefficients of solutes at infinite dilution in sub and supercritical solvents. We have also investigated the behavior of Fick diffusion coefficients in the proximity of a binary vapor-liquid critical point since this subject is of great interest for extraction purposes. The approach presented here, which makes use of a density and temperature dependent hard-sphere diameter, is shown to be excellent for predicting diffusivities in dense pure fluids and fluid mixtures. The calculations involved highly nonideal mixtures as well as systems with high molecular asymmetry. The predicted diffusivities are in good agreement with the experimental data for the pure and binary systems. The methodology proposed here makes only use of pure component information and density of mixtures. The simple algebraic relations are proposed without any binary adjustable parameters and can be readily used for estimating diffusivities in multicomponent mixtures.

  5. Two-Microphone Separation of Speech Mixtures

    DEFF Research Database (Denmark)

    Pedersen, Michael Syskind; Wang, DeLiang; Larsen, Jan

    2008-01-01

    combined, independent component analysis (ICA) and binary time–frequency (T–F) masking. By estimating binary masks from the outputs of an ICA algorithm, it is possible in an iterative way to extract basis speech signals from a convolutive mixture. The basis signals are afterwards improved by grouping...

  6. Wind Integration into Various Generation Mixtures

    NARCIS (Netherlands)

    Maddaloni, J.D.; Rowe, A.M.; Kooten, van G.C.

    2009-01-01

    A load balance model is used to quantify the economic and environmental effects of integrating wind power into three typical generation mixtures. System operating costs over a specified period are minimized by controlling the operating schedule of the existing power generating facilities for a range

  7. Modeling text with generalizable Gaussian mixtures

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Sigurdsson, Sigurdur; Kolenda, Thomas

    2000-01-01

    We apply and discuss generalizable Gaussian mixture (GGM) models for text mining. The model automatically adapts model complexity for a given text representation. We show that the generalizability of these models depends on the dimensionality of the representation and the sample size. We discuss...

  8. Semiparametric mixtures in case-controlstudies

    NARCIS (Netherlands)

    Murphy, S.A.; van der Vaart, A.W.

    2001-01-01

    We consider likelihood based inference in a class of logistic models for case-control studies with a partially observed covariate. The likelihood is a combination of a nonparametric mixture, a parametric likelihood, and an empirical likelihood. We prove the asymptotic normality of the maximum

  9. Thermodynamic modeling of CO2 mixtures

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel

    Knowledge of the thermodynamic properties and phase equilibria of mixtures containing carbon dioxide (CO2) is important in several industrial processes such as enhanced oil recovery, carbon capture and storage, and supercritical extractions, where CO2 is used as a solvent. Despite this importance...

  10. 16 CFR 1500.5 - Hazardous mixtures.

    Science.gov (United States)

    2010-01-01

    ..., flammable, sensitizing, or pressure-generating properties of a substance from what is known about its... Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.5 Hazardous mixtures...

  11. Optimal designs for linear mixture models

    NARCIS (Netherlands)

    Mendieta, E.J.; Linssen, H.N.; Doornbos, R.

    1975-01-01

    In a recent paper Snee and Marquardt [8] considered designs for linear mixture models, where the components are subject to individual lower and/or upper bounds. When the number of components is large their algorithm XVERT yields designs far too extensive for practical purposes. The purpose of this

  12. Meso Mechanical Analysis of AC Mixture Response

    NARCIS (Netherlands)

    Woldekidan, M.F.; Huurman, M.; Vaccari, E.; Poot, M.

    2012-01-01

    Ongoing research into performance modeling of Asphalt Concrete (AC) mixtures using meso mechanics approaches is being undertaken at Delft University of Technology (TUD). The approach has already been successfully employed for evaluating the long term performance of porous asphalt concrete. The work

  13. Optimal designs for linear mixture models

    NARCIS (Netherlands)

    Mendieta, E.J.; Linssen, H.N.; Doornbos, R.

    1975-01-01

    In a recent paper Snee and Marquardt (1974) considered designs for linear mixture models, where the components are subject to individual lower and/or upper bounds. When the number of components is large their algorithm XVERT yields designs far too extensive for practical purposes. The purpose of

  14. Bayesian mixture analysis for metagenomic community profiling.

    Science.gov (United States)

    Morfopoulou, Sofia; Plagnol, Vincent

    2015-09-15

    Deep sequencing of clinical samples is now an established tool for the detection of infectious pathogens, with direct medical applications. The large amount of data generated produces an opportunity to detect species even at very low levels, provided that computational tools can effectively profile the relevant metagenomic communities. Data interpretation is complicated by the fact that short sequencing reads can match multiple organisms and by the lack of completeness of existing databases, in particular for viral pathogens. Here we present metaMix, a Bayesian mixture model framework for resolving complex metagenomic mixtures. We show that the use of parallel Monte Carlo Markov chains for the exploration of the species space enables the identification of the set of species most likely to contribute to the mixture. We demonstrate the greater accuracy of metaMix compared with relevant methods, particularly for profiling complex communities consisting of several related species. We designed metaMix specifically for the analysis of deep transcriptome sequencing datasets, with a focus on viral pathogen detection; however, the principles are generally applicable to all types of metagenomic mixtures. metaMix is implemented as a user friendly R package, freely available on CRAN: http://cran.r-project.org/web/packages/metaMix sofia.morfopoulou.10@ucl.ac.uk Supplementary data are available at Bionformatics online. © The Author 2015. Published by Oxford University Press.

  15. Electron scattering in dense He-Ar gas mixtures: A pressure shift study

    International Nuclear Information System (INIS)

    Asaf, U.; Felps, W.S.; McGlynn, S.P.

    1989-01-01

    The dependence of the energies of high-n Rydberg states of CH 3 I on the molar composition of helium-argon mixtures (in the number density range 1.3x10 20 --5.6x10 20 cm -3 ) is reported. The energy shifts, when normalized to a given density value, are found to vary linearly with the mole fraction of either component of the binary, rare-gas mixture. The observed change in sign of the energy shift is attributable to the different signs of the electron scattering lengths for the two rare-gas components. As a result, there exists a mixture composition, at a mole ratio [He]/[Ar]=2.0, at which the shift is null. The experimental results for the gas mixture agree with the Fermi formula, as modified to include the Alekseev-Sobel'man polarization term. Effective electron scattering lengths and cross sections, polarizabilities, and thermal velocities are used to characterize the effects of the binary gas perturber system

  16. Thermophysical properties of binary mixtures of N,N-dimethylformamide with three cyclic ethers

    Directory of Open Access Journals (Sweden)

    Sinha Biswajit

    2013-01-01

    Full Text Available Densities and viscosities of the binary mixtures consisting of tetrahydrofuran (THF, 1,3-dioxolane (1,3-DO and 1,4-dioxane (1,4-DO with N,N-dimethylformamide (DMF over the entire range of composition were measured at temperatures 298.15, 308.15 and 318.15 K and at atmospheric pressure. Ultrasonic speeds of sound of these binary mixtures were measured at ambient temperature and atmospheric pressure (T = 298.15 K and P = 1.01×105 Pa. The various experimental data were utilized to derive excess molar volumes (VmE, excess viscosities (ηE, and excess isentropic compressibilities (κsE. Using the excess molar volumes (VmE, excess partial molar volumes (and and excess partial molar volumes at infinite dilution (and of each liquid component in the mixtures were derived and discussed. Excess molar volumes (VmE as a function of composition at ambient temperature and atmospheric pressure were used further to test the applicability of the Prigogine-Flory-Patterson (PFP theory to the experimental binaries. The excess properties were found to be either negative or positive depending on the nature of molecular interactions and structural effects of liquid mixtures. Em,1V Em,2VE0,m,1VE0,m,2V.

  17. Measurement and correlation of critical properties for binary mixtures and ternary mixtures containing gasoline additives

    International Nuclear Information System (INIS)

    Wang, Lipu; Han, Kewei; Xia, Shuqian; Ma, Peisheng; Yan, Fangyou

    2014-01-01

    Highlights: • A high-pressure view cell was used to measure the critical properties of mixtures. • Three binary mixtures’ and three ternary mixtures’ critical properties were reported. • The experimental data of each system covered the whole mole fraction range. • The critical properties of the ternary mixtures were predicted with the PR–WS model. • Empirical equations were used to correlate the experimental results. - Abstract: The critical properties of three binary mixtures and three ternary mixtures containing gasoline additives (including methanol + 1-propanol, heptane + ethanol, heptane + 1-propanol, methanol + 1-propanol + heptane, methanol + 1-propanol + methyl tert-butyl ether (MTBE), and ethanol + heptane + MTBE) were determined by a high-pressure cell. All the critical lines of binary mixtures belong to the type I described by Scott and van Konynenburg. The system of methanol + 1-propanol showed little non-ideal behavior due to their similar molecular structures. The heptane + ethanol and heptane + 1-propanol systems showed visible non-ideal behavior for their great differences in molecular structure. The Peng–Robinson equation of state combined with the Wong–Sandler mixing rule (PR–WS) was applied to correlate the critical properties of binary mixtures. The critical points of the three ternary mixtures were predicted by the PR–WS model with the binary interaction parameters using the procedure proposed by Heidemann and Khalil. The predicted critical temperatures were in good agreement with the experimental values, while the predicted critical pressures differed from the measured values. The experimental values of binary mixtures were fitted well with the Redlich–Kister equation. The critical properties of ternary mixtures were correlated with the Cibulka’s equation, and the critical surfaces were plotted using the Cibulka’s equations

  18. Coating material composition

    International Nuclear Information System (INIS)

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Maeda, Yutaka.

    1969-01-01

    A coating material composition is provided which can easily be cross-linked by irradiation with active energy, particularly electron beams and ultraviolet light, using a mixture of a prepolymer (a) with an addition reaction product (b). Such compositions have coating properties as good as thermosetting acrylic or amino alkyd resins. The prepolymer (a) is produced by primarily reacting at least 0.1 mol of saturated cyclocarboxylic acid anhydrides and/or alpha-, beta-ethylene unsaturated carboxylic acid anhydrides by addition reaction with one mol of hydroxyl radicals of a basic polymer having a molecular weight of 1,000 to 100,000, the basic polymer being obtained from 1%-40% of a hydroxyl radical containing vinyl monomer and at least 30% of (meth)acrylate monomer. One mol of the sum of hydroxyl radicals and carboxyl radicals of the primary reaction product undergoes a secondary addition reaction with at least 0.1 mol of an epoxy radical-containing vinyl monomer to form the prepolymer(a). The addition reaction product(b) is produced by reacting an epoxy radical-containing vinyl monomer with alpha-, beta-ethylene unsaturated carboxylic acids or their anhydrides. The coating material composition contains a majority of a mixture consisting of 10%-90% of (a) and 90%-10% of (b) above by weight. Four examples of the production of basic polymers, seven examples of the production of prepolymers, seven examples of the production of oligomers, and five examples of applications are given. (Iwakiri, K.)

  19. NON-EQUILIBRIUM MOLECULAR DYNAMICS USED TO OBTAIN SORET COEFFICIENTS OF BINARY HYDROCARBON MIXTURES

    Directory of Open Access Journals (Sweden)

    F. A. Furtado

    2015-09-01

    Full Text Available AbstractThe Boundary Driven Non-Equilibrium Molecular Dynamics (BD-NEMD method is employed to evaluate Soret coefficients of binary mixtures. Using a n-decane/n-pentane mixture at 298 K, we study several parameters and conditions of the simulation procedure such as system size, time step size, frequency of perturbation, and the undesired warming up of the system during the simulation. The Soret coefficients obtained here deviated around 20% when comparing with experimental data and with simulated results from the literature. We showed that fluctuations in composition gradients and the consequent deviations of the Soret coefficient may be due to characteristic fluctuations of the composition gradient. Best results were obtained with the smallest time steps and without using a thermostat, which shows that there is room for improvement and/or development of new BD-NEMD algorithms.

  20. Nutritional, microbiological and sensorial characteristics of alfajor prepared with dehydrated mixture of salmon and tilapia

    Directory of Open Access Journals (Sweden)

    Kátia Setsuko Kimura

    2017-02-01

    Full Text Available Current assay deals with the preparation of alfajores with different levels (0 to 15% of dehydrated fish mixture of salmon (10% and tilapia (90% to assess the sensorial characteristics and their centesimal composition and microbiological. Fish inclusion in alfajores did not affect the aroma, taste, texture, color and physical aspect, with scores ranging between 6.70 and 7.96 of a hedonic scale of 9 score. An average score of 4 in a 5-score purchasing intention scale was obtained, or rather, tasters would probably buy the product. In the case of centesimal composition, inclusion affected (p 0.05 in lipids and calorie rates in the alfajores. Results show that the inclusion of up to 15% of a dehydrated mixture of salmon (10% and tilapia (90% in alfajores was greatly accepted and improved their nutrition values. Further, the product was also within the microbiological standards required by Brazilian sanitary laws.